Oriented Carbon Fiber Networks by Design from Renewables for Electrochemical ApplicationsClick to copy article linkArticle link copied!
- Jiayuan WeiJiayuan WeiDepartment of Engineering Sciences and Mathematics, Luleå University of Technology, SE-97187 Luleå, SwedenMore by Jiayuan Wei
- Faiz Ullah ShahFaiz Ullah ShahChemistry of Interfaces, Luleå University of Technology, SE-97187 Luleå, SwedenMore by Faiz Ullah Shah
- Lisa Johansson CarneLisa Johansson CarneDepartment of Engineering Sciences and Mathematics, Luleå University of Technology, SE-97187 Luleå, SwedenMore by Lisa Johansson Carne
- Shiyu GengShiyu GengDepartment of Engineering Sciences and Mathematics, Luleå University of Technology, SE-97187 Luleå, SwedenMore by Shiyu Geng
- Oleg N. AntzutkinOleg N. AntzutkinChemistry of Interfaces, Luleå University of Technology, SE-97187 Luleå, SwedenMore by Oleg N. Antzutkin
- Mohini SainMohini SainMechanical & Industrial Engineering (MIE), University of Toronto, Toronto, ON M5S 3G8, CanadaMore by Mohini Sain
- Kristiina Oksman*Kristiina Oksman*Email: [email protected]Department of Engineering Sciences and Mathematics, Luleå University of Technology, SE-97187 Luleå, SwedenMechanical & Industrial Engineering (MIE), University of Toronto, Toronto, ON M5S 3G8, CanadaMore by Kristiina Oksman
Abstract
With the explosion of global demands for electrified mobility systems and a surge in rural energy transport mechanisms augmented by the scarcity of key metals, carbon by design has become a transformational pathway to fill the gap as an energy material of choice. The development of functional carbon from renewables with outstanding electrostatic double-layer capacitance is still in its infancy, as there is a significant gap in understanding the relationship between the tunable structure and properties of the bioresources both before and after their controlled carbonization. Herein, we report carbon fiber networks (CFNs) with highly controllable intact structure manufactured from four functional lignins originating from different types of processing residues, demonstrating excellent electrochemical efficacies, which makes them promising self-standing electrodes in supercapacitors. This study also underpins the feasibility and importance of preparing CFNs with highly oriented structure, which endows superior specific capacitance and cycle stability compared to the CFNs with randomly oriented fibers. The randomly oriented CFNs reached a specific capacitance value of 456 F g–1 under current densities of 1 A g–1 and a cycle stability of 73.6%, while the CFNs with an orientation factor of 0.87 exhibited significant improvement of the specific capacitance by approximately 15% (529 F g–1) and the cycle stability reached 95% after 10 000 charge–discharge cycles. The high specific capacitance and excellent overall electrochemical properties of the highly oriented CFNs make them a cost-effective and greener material of choice for energy storage devices.
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License Summary*
You are free to share(copy and redistribute) this article in any medium or format and to adapt(remix, transform, and build upon) the material for any purpose, even commercially within the parameters below:
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Synopsis
Green carbon fiber networks with outstanding electrochemical performance can be produced from lignin, a main byproduct in biorefinery and paper-making industries.
Introduction
Results and Discussion
Figure 1
Figure 1. (a) 400.27 MHz 1H NMR spectra of LB, KR, HY, and SD dissolved in DMSO-d6. The 1H NMR resonance line at 2.50 ppm present in all the spectra corresponds to the solvent DMSO-d5(H). Assignment of protons in (i) CH2, CH3; (ii) CH2, CH; (iii) CH, CH3O, CH2O, CHO; (iv) aromatic H; (v) aromatic OH; and (vi) COOH. (b) 100.64 MHz 13C CP-MAS NMR spectra of LB, KR, HY, and SD. The MAS frequency was 8 kHz.
lignin | relative integral intensitiesa | |||
---|---|---|---|---|
85–0 ppmb | 56 ppmc | 74 ppmd | 50–0 ppme | |
LB | 0.94 | 0.29 | 0.09 | 0.45 |
KR | 1.18 | 0.33 | 0.13 | 0.53 |
HY | 1.19 | 0.27 | 0.08 | 0.67 |
SD | 1.33 | 0.33 | 0.17 | 0.63 |
Normalized to the integral intensity of aromatic carbons (integrated in the range of 162–102 ppm).
All-aliphatic carbons.
Methoxyl carbons (integrated in the range of 60–50 ppm).
Substituted sp3 (CO) carbons, carbohydrates (integrated in the range of 77–67 ppm).
Unsubstituted sp3 carbons.
Mw (Da) | Mn (Da) | PDI | |
---|---|---|---|
LB | 4202 | 741 | 5.57 |
KRa | ca. 10 000 | N.A. | N.A. |
SD | 2219 | 601 | 3.69 |
HY | 7367 | 664 | 11.1 |
According to the information from the supplier.
Figure 2
Figure 2. Thermogravimetric analysis of LB, KR, HY, and SD in N2 atmosphere.
Figure 3
Figure 3. Optical microscopy image of the (a) LB, (b) KR, (c) HY, and (d) SD solutions used for preparing the electrospinning precursor.
sample code | lignin | speed of the collector (rpm) | carbonization |
---|---|---|---|
LB200 | LB | 200 | no |
KR200 | KR | 200 | no |
HY200 | HY | 200 | no |
SD200 | SD | 200 | no |
LB1500 | LB | 1500 | no |
C-LB200 | LB | 200 | yes |
C-KR200 | KR | 200 | yes |
C-HY200 | HY | 200 | yes |
C-SD200 | SD | 200 | yes |
C-LB1500 | LB | 1500 | yes |
Figure 4
Figure 4. SEM images and the fiber diameter distributions of (a) C-LB200, (b) C-KR200, (c) C-HY200, and (d) C-SD200.
Figure 5
Figure 5. Orientation-related colored SEM images of (a) C-LB200, (b) C-KR200, (c) C-HY200, and (d) C-SD200. Zero degree corresponds to the vertical direction.
SEM-EDX | |||||||
---|---|---|---|---|---|---|---|
sample | C (at. %) | O (at. %) | Na (at. %) | S (at. %) | K (at. %) | SSA (m2 g–1) | pore sizea (nm) |
C-LB200 | 93.3 | 5.4 | 0.6 | 0.7 | 0.0 | 715 | 1.7 |
C-KR200 | 95.7 | 3.4 | 0.2 | 0.4 | 0.1 | 1241 | 1.8 |
C-HY200 | 93.9 | 5.2 | 0.2 | 0.7 | 0.0 | 1268 | 2.2 |
C-SD200 | 96.4 | 2.7 | 0.5 | 0.4 | 0.2 | 1286 | 2.2 |
C-LB1500 | 95.4 | 3.4 | 0.6 | 0.5 | 0.0 | 700 | 1.7 |
Adsorption average pore diameter (4 V/A by BET).
Figure 6
Figure 6. Raman spectra of C-LB200, C-KR200, C-HY200, and C-SD200.
Figure 7
Figure 7. Electrochemical properties of the randomly oriented CFNs. (a) Cyclic voltammograms (CV) of C-LB200, C-KR200, C-HY200, and C-SD200 under a scan rate of 100 mV s–1. (b) Galvanostatic charge–discharge (GCD) profiles of C-LB200, C-KR200, C-HY200, and C-SD200 using a current density of 10 A g–1. (c) Summary of the specific capacitance of C-LB200, C-KR200, C-HY200, and C-SD200 from the GCD under a series of current density. (d) Capacitance retention of C-LB200, C-KR200, C-HY200, and C-SD200 during 10 000 charge–discharge cycles under a current density of 10 A g–1.
precursor materials | cell configuration | electrolyte | current density (A g–1) | Celec (F g–1) | ref |
---|---|---|---|---|---|
modified lignin/polyacrylonitrile | three-electrode | 6 M KOH | 1 | 428.9 | (53) |
kraft lignin | two-electrode | 6 M KOH | 0.1 | 155 | (54) |
kraft lignin/poly(vinylpyrrolidone)/Zn(NO3)2 | three-electrode | 6 M KOH | 0.1 | 217 | (55) |
20 | 152 | ||||
hydrolyzed lignin/polyacrylonitrile/poly(methyl methacrylate) | three-electrode | 6 M KOH | 0.5 | 233 | (56) |
kraft lignin/PVA | two-electrode | 6 M KOH | 0.8 | 179.2 | (29) |
kraft lignin/PVA | two-electrode | 6 M KOH | 0.4 | 64 | (30) |
lignoboost lignin/PVA | three-electrode | 1 M H2SO4 | 1 | 456.1 | this study |
Figure 8
Figure 8. Fiber morphology of the as-spun and the carbonized fiber networks. (a) SEM image of LB200, (b) SEM image of LB1500, (c) fiber diameter distribution of LB200 and LB1500, (d) SEM image of C-LB200, (e) SEM image of C-LB1500, and (f) fiber diameter distribution of C-LB200 and C-LB1500.
Figure 9
Figure 9. Orientation-related colored SEM images of (a) LB200, (b) LB-1500, (d) C-LB200, and (e) C-LB1500. Orientation distribution graphs of (c) LB200 and LB1500 and (f) C-LB200 and C-LB1500. Zero degree is aligned to the vertical direction.
Figure 10
Figure 10. Comparison of the electrochemical properties between the randomly oriented and highly oriented CFNs. (a) CV of C-LB1500. (b) GCD of C-LB1500. (c) CV of C-LB200 and C-LB1500 under a scan rate of 100 mV s–1. (d) GCD curves of C-LB200 and C-LB1500 using a current density of 10 A g–1. (e) Summary of the specific capacitance of C-LB200 and C-LB1500 from the GCD under a series of current densities. (f) Capacitance retention of C-LB200 and C-LB1500 during charge–discharge cycles under a current density of 10 A g–1.
Figure 11
Figure 11. Nyquist diagrams for C-LB200 and C-LB1500 obtained using electrochemical impedance spectroscopy (EIS). The testing potential is 300 mV.
Conclusion
Experimental Section
Materials
Electrospinning of Lignin-Based Fibers
LB | KR | HY | SD | |
---|---|---|---|---|
solid contenta (wt %) | 16 | 19 | 16 | 19 |
lignin (g) | 3.0 | 3.3 | 3.0 | 3.6 |
PVAb (g) | 1.0 | 1.1 | 1.0 | 1.2 |
H2O (g) | 20.7 | 19.0 | 20.7 | 20.0 |
NaOH (g) | 0.3 | 0.0 | 0.3 | 0.3 |
pH | 11.3 | 8.7 | 11.2 | 10.6 |
voltage (kV) | 16.0 | 16.0 | 20.0 | 20.0 |
feeding rate (8 mL h–1) | 0.40 | 0.20 | 0.45 | 0.25 |
Only PVA and lignin contributed to the solid content in the calculation.
PVA is a commonly used binder polymer to facilitate the electrospinning of lignin-dominated precursor. According to the study from Ago et al., (62) a continuous phase of lignin has been found on surfaces of the electrospun fibers using this lignin/PVA ratio. Lai et al. (30) reported that pure PVA fibers formed less porous carbon with a low degree of graphitic order when carbonized.
Carbonization of the As-Spun fFbers
Characterization


Supporting Information
The Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/acssuschemeng.1c03549.
13C NMR spectra of lignins; molecule size distribution of lignins; magnified OM image of SD solution; illustration of the electrospinning setup; SEM images of as-spun fiber networks; CV plots and GCD curves of CFNs; bending test of the electrode after the electrochemical testing; N2 adsorption isotherms of the CFNs at 77 K; pore size distribution of the CFNs based on nonlocal density functional theory (PDF)
Terms & Conditions
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Acknowledgments
The authors acknowledge the Swedish Research Council (Carbon Lignin 2017-04240), Swedish Strategic Research Program Bio4Energy, and Business Finland (Grelectronics) for their financial support. St1 Oy (Helsinki, Finland) is acknowledged for providing the hydrolysis lignin. We are thankful to Ms. Elisa Wirkkala at the University of Oulu for the purification of hydrolysis lignin. Dr. Manish Kumar and the Chemical Process Engineering Research Unit at the University of Oulu are acknowledged for conducting the GPC test. We also thank the Kempe Foundation in memory of J. C. and Seth M. Kempe (project numbers JCK-1306 and JCK-1433) and the laboratory fund at Luleå University of Technology (LTU) for providing grants, from which a Bruker Aeon/Avance III NMR spectrometer at LTU was purchased.
References
This article references 68 other publications.
- 1Bajpai, P. Lignin. In Carbon Fibre from Lignin; Springer Nature: Singapore, 2017; pp 11– 15.Google ScholarThere is no corresponding record for this reference.
- 2Henriksson, G. Lignin. In Wood chemistry and biotechnology; Ek, M., Gellerstedt, G., Henriksson, G., Eds.; Pulp and Paper Chemistry and Technology; Walter de Gruyter GmbH & Co.: Berlin, Germany, 2009; Vol. 1, pp 121– 145.Google ScholarThere is no corresponding record for this reference.
- 3Yuan, T.-Q.; Sun, S.-N.; Xu, F.; Sun, R.-C. Characterization of Lignin Structures and Lignin–Carbohydrate Complex (LCC) Linkages by Quantitative 13C and 2D HSQC NMR Spectroscopy. J. Agric. Food Chem. 2011, 59 (19), 10604– 10614, DOI: 10.1021/jf2031549Google Scholar3https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXhtFKnt7rM&md5=2674734ad70922c56ab1741ecc6e5aadCharacterization of Lignin Structures and Lignin-Carbohydrate Complex (LCC) Linkages by Quantitative 13C and 2D HSQC NMR SpectroscopyYuan, Tong-Qi; Sun, Shao-Ni; Xu, Feng; Sun, Run-CangJournal of Agricultural and Food Chemistry (2011), 59 (19), 10604-10614CODEN: JAFCAU; ISSN:0021-8561. (American Chemical Society)To characterize the lignin structures and lignin-carbohydrate complex (LCC) linkages, milled wood lignin (MWL) and mild acidolysis lignin (MAL) with a high content of assocd. carbohydrates were sequentially isolated from ball-milled poplar wood. Quantification of their structural features has been achieved by using a combination of quant. 13C and 2D HSQC NMR techniques. The results showed that acetylated 4-O-methylgluconoxylan is the main carbohydrate assocd. with lignins, and acetyl groups frequently acylate the C2 and C3 positions. MWL and MAL exhibited similar structural features. The main substructures were β-O-4' aryl ether, resinol, and phenylcoumaran, and their abundances per 100 Ar units changed from 41.5 to 43.3, from 14.6 to 12.7, and from 3.7 to 4.0, resp. The S/G ratios were estd. to be 1.57 and 1.62 for MWL and MAL, resp. Ph glycoside and benzyl ether LCC linkages were clearly quantified, whereas the amt. of γ-ester LCC linkages was ambiguous for quantification.
- 4Gierer, J. Chemical Aspects of Kraft Pulping. Wood Sci. Technol. 1980, 14 (4), 241– 266, DOI: 10.1007/BF00383453Google Scholar4https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaL3MXmslCnsQ%253D%253D&md5=e05b14fbda370a2fe83da74433159218Chemical aspects of kraft pulpingGierer, J.Wood Science and Technology (1980), 14 (4), 241-66CODEN: WOSTBE; ISSN:0043-7719.In kraft pulping of wood chips, degrdn. and condensation reactions of lignin, the formation of quinone methide intermediates, the course of delignification, and degrdn. of carbohydrates are reviewed with 75 refs.
- 5Gosselink, R. J. A. Lignin as a Renewable Aromatic Resource for the Chemical Industry . Ph.D. Thesis, Wageningen University, Wageningen, Netherlands, 2011.Google ScholarThere is no corresponding record for this reference.
- 6Chakar, F. S.; Ragauskas, A. J. Review of Current and Future Softwood Kraft Lignin Process Chemistry. Ind. Crops Prod. 2004, 20 (2), 131– 141, DOI: 10.1016/j.indcrop.2004.04.016Google Scholar6https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2cXotFCntb0%253D&md5=cf61bb642b156646310842fa001f465bReview of current and future softwood kraft lignin process chemistryChakar, Fadi S.; Ragauskas, Arthur J.Industrial Crops and Products (2004), 20 (2), 131-141CODEN: ICRDEW; ISSN:0926-6690. (Elsevier B.V.)A review. The structure of lignin has remained one of the most difficult biopolymers to characterize, however recent advances in anal. chem. and spectroscopy have dramatically improved our knowledge of this natural resource. This paper highlights our current understanding of lignin structure and examines the process chem. surrounding kraft pulping. The application of this knowledge, with respect to converting lignin into novel biomaterials, biocomposites, and biofuels is examd. briefly.
- 7Henriksson, G.; Li, J.; Zhang, L.; Lindström, M. Lignin Utilization. In Thermochemical Conversion of Biomass to Liquid Fuels and Chemicals; Crocker, M., Ed.; RSC Energy and Environment Series; Royal Society of Chemistry: London, 2010.Google ScholarThere is no corresponding record for this reference.
- 8Lora, J. H. Lignin: A Platform for Renewable Aromatic Polymeric Materials. Quality Living Through Chemurgy and Green Chemistry; Springer: Berlin, Heidleberg, Germany, 2016; pp 221– 261.Google ScholarThere is no corresponding record for this reference.
- 9Biermann, C. J. Handbook of Pulping and Papermaking; Academic Press: Cambridge, MA, 1996.Google ScholarThere is no corresponding record for this reference.
- 10Chapple, C.; Ladisch, M.; Meilan, R. Loosening Lignin’s Grip on Biofuel Production. Nat. Biotechnol. 2007, 25 (7), 746– 748, DOI: 10.1038/nbt0707-746Google Scholar10https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2sXnsFartbw%253D&md5=688db6d460b0c70686522c899d66576fLoosening lignin's grip on biofuel productionChapple, Clint; Ladisch, Michael; Meilan, RickNature Biotechnology (2007), 25 (7), 746-748CODEN: NABIF9; ISSN:1087-0156. (Nature Publishing Group)There is no expanded citation for this reference.
- 11Raud, M.; Tutt, M.; Olt, J.; Kikas, T. Dependence of the Hydrolysis Efficiency on the Lignin Content in Lignocellulosic Material. Int. J. Hydrogen Energy 2016, 41 (37), 16338– 16343, DOI: 10.1016/j.ijhydene.2016.03.190Google Scholar11https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC28XmtVOns70%253D&md5=6bc5c56da2fdda2a254e291abb84630cDependence of the hydrolysis efficiency on the lignin content in lignocellulosic materialRaud, M.; Tutt, M.; Olt, J.; Kikas, T.International Journal of Hydrogen Energy (2016), 41 (37), 16338-16343CODEN: IJHEDX; ISSN:0360-3199. (Elsevier Ltd.)Lignocellulosic material is the most promising feedstock for bioethanol prodn.; however, due to the varying physicochem. characteristics of different biomasses, it is necessary to select a biomass suitable for bioethanol prodn. For this purpose, several different alternative non-food energy crops were chosen to investigate their suitability for bioethanol prodn., considering their cellulose, hemicellulose and lignin content. The traditional three-step bioethanol prodn. process was used, where dil. acid was applied for biomass pre-treatment. Glucose and ethanol yields and hydrolysis efficiency were used to evaluate the suitability of different energy crops for bioethanol prodn. The results show that the glucose yield increases as the cellulose content in the biomass rises. However, a sharp decrease in hydrolysis efficiency was noted in the lignin content range of 7-9 g 100 g-1. The lower hydrolysis efficiency also resulted in a lower ethanol yield in the next step of the bioethanol prodn. process.
- 12Ragauskas, A. J.; Beckham, G. T.; Biddy, M. J.; Chandra, R.; Chen, F.; Davis, M. F.; Davison, B. H.; Dixon, R. A.; Gilna, P.; Keller, M. Lignin Valorization: Improving Lignin Processing in the Biorefinery. Science 2014, 344, 6185, DOI: 10.1126/science.1246843Google ScholarThere is no corresponding record for this reference.
- 13Fache, M.; Boutevin, B.; Caillol, S. Vanillin Production from Lignin and Its Use as a Renewable Chemical. ACS Sustainable Chem. Eng. 2016, 4 (1), 35– 46, DOI: 10.1021/acssuschemeng.5b01344Google Scholar13https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXhvF2itr7E&md5=3c96f266ab9350361267bfaea10790b1Vanillin Production from Lignin and Its Use as a Renewable ChemicalFache, Maxence; Boutevin, Bernard; Caillol, SylvainACS Sustainable Chemistry & Engineering (2016), 4 (1), 35-46CODEN: ASCECG; ISSN:2168-0485. (American Chemical Society)A review. The use of vanillin as a building block for the chem. industry is discussed in this article. Vanillin is currently one of the only mol. phenolic compds. manufd. on an industrial scale from biomass. It has thus the potential to become a key-intermediate for the synthesis of bio-based polymers, for which arom. monomers are needed to reach good thermo-mech. properties. After a first part dedicated to the current sousing of vanillin, this article focuses on the alk. oxidn. lignin-to-vanillin process, reporting advantages and limits, discusses the various post-depolymn. methods for product isolation and finally examines the outlook for the wider use of vanillin as a key building block for the chem. industry.
- 14Culebras, M.; Sanchis, M. J.; Beaucamp, A.; Carsí, M.; Kandola, B. K.; Horrocks, A. R.; Panzetti, G.; Birkinshaw, C.; Collins, M. N. Understanding the Thermal and Dielectric Response of Organosolv and Modified Kraft Lignin as a Carbon Fibre Precursor. Green Chem. 2018, 20 (19), 4461– 4472, DOI: 10.1039/C8GC01577EGoogle Scholar14https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1cXhtlajsbrI&md5=f5f8e66e7cc1de8b4190bec0844c5e89Understanding the thermal and dielectric response of organosolv and modified kraft lignin as a carbon fibre precursorCulebras, Mario; Sanchis, Maria J.; Beaucamp, Anne; Carsi, Marta; Kandola, Baljinder K.; Horrocks, A. Richard; Panzetti, Gianmarco; Birkinshaw, Colin; Collins, Maurice N.Green Chemistry (2018), 20 (19), 4461-4472CODEN: GRCHFJ; ISSN:1463-9262. (Royal Society of Chemistry)Understanding the thermal behavior of lignin is crucial to realize its valorization as an engineering polymer. Two hardwood lignins, organosolv (OSL) and chem. modified kraft lignin (ML) were chosen to represent important classes of renewable and abundant raw materials. The relation between ionic mobility and viscosity in OSL and ML was studied. The rheol. results were interpreted in terms of the competitive processes of thermal plasticization and stiffening through crosslinking. Results show that with OSL, crosslinking proceeds relatively rapidly, and this is consistent with its more reactive structure. Higher mol. wt. (Mw) influenced the melt stability as crosslinking kinetics was reduced and this was attributed to the redn. of chain ends available for crosslinking reactions. Scanning calorimetry has shown that both materials are glassy and pass through the glass transition between 100 °C and 115 °C, with the higher mol. wt. modified material having a slightly higher Tg. Both lignins show pronounced maxima in the Gram-Schmidt plots for methane or methanol around 400 °C. However, a significant difference between the materials is obsd. with the detection of a strong carbonyl peak in the evolution products of the ML, which is attributed to the scission of the hydroxypropyl substituent present in the ML structure. The differences in the degrdn. processes are further reflected in the dielec. properties of the partially degraded materials where loss maxima occur at different temps. and show different degrees of frequency dependence. An important observation is the difference in cond., where higher values for OSL are attributed to the crosslinking between adjacent benzene rings, whereas with the ML, a lower cond. is assocd. with intrinsically less conductive intermol. linkages. These results demonstrate that the thermal decompn. of the two lignins follows significantly different paths at the mol. level. With the more reactive OSL, it appears to be the case that there is a greater tendency to form direct ring to ring crosslinks and this is significant for the properties of the intended end product.
- 15Jiang, W.; Liu, S.; Wu, C.; Liu, Y.; Yang, G.; Ni, Y. Super-Stable, Solvent-Resistant and Uniform Lignin Nanorods and Nanospheres with a High Yield in a Mild and Facile Process. Green Chem. 2020, 22 (24), 8734– 8744, DOI: 10.1039/D0GC02887HGoogle Scholar15https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXitlKktLbF&md5=78b9e7be09cfc218ffe5119de547d2f9Super-stable, solvent-resistant and uniform lignin nanorods and nanospheres with a high yield in a mild and facile processJiang, Weikun; Liu, Shuyun; Wu, Chaojun; Liu, Yu; Yang, Guihua; Ni, YonghaoGreen Chemistry (2020), 22 (24), 8734-8744CODEN: GRCHFJ; ISSN:1463-9262. (Royal Society of Chemistry)Lignin-based nanomaterials have attracted much attention in value-added functional material fields due to their green/sustainable nature; however, it is a challenge to control the morphol. of lignin nanoparticles, and furthermore, to make them stable in org. solvent systems. Herein, for the first time we developed a green and simple approach for producing lignin nanorods, in addn. to lignin nanospheres, both of which are stable in various org. solvents. The prepn. process involves two steps: (1) lignosulfonate (LS) is fractionated into three fractions, namely, LS90, LS70, and LS40 using 90% ethanol, 70% ethanol and 40% ethanol sequentially; (2) lignin nanorods are obtained from the LS40 fraction, while lignin nanospheres are obtained from LS70 by an anti-solvent method. During the lignin self-assembly process, for the LS40 fraction, the lignin structures are in a flat oblate ellipsoid conformation, and the J-aggregation of their arom. structures occurs on the flat sides of the oblate ellipsoid, leading to the formation of lignin nanorods. In contrast, for the LS70 fraction, lignin aggregation occurs randomly because of its near-spherical small ellipsoid conformation in soln., leading to the formation of lignin nanospheres. The entire prepn. process of lignin nanorods and lignin nanospheres is simple, without the use of templates, complex chem. reactions and rigorous conditions. The lignin nanorods and lignin nanospheres exhibit excellent uniformity and dispersibility, and long-term stability in various org. solvents. This study not only presents a green, facile and economical approach for prepg. lignin nanorods, as well as lignin nanospheres, but also provides a promising new value-added utilization pathway for lignosulfonate.
- 16Yang, Y.; Deng, Y.; Tong, Z.; Wang, C. Renewable Lignin-Based Xerogels with Self-Cleaning Properties and Superhydrophobicity. ACS Sustainable Chem. Eng. 2014, 2 (7), 1729– 1733, DOI: 10.1021/sc500250bGoogle Scholar16https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXpt1yqsL4%253D&md5=ef9ab4c06e766627b2f36c9b00c4655eRenewable Lignin-Based Xerogels with Self-Cleaning Properties and SuperhydrophobicityYang, Yu; Deng, Yonghong; Tong, Zhen; Wang, ChaoyangACS Sustainable Chemistry & Engineering (2014), 2 (7), 1729-1733CODEN: ASCECG; ISSN:2168-0485. (American Chemical Society)A novel diisocyanate-modified lignin xerogel is facilely prepd. using renewable lignin as precursors via a sol-gel process and ambient pressure drying method. The xerogel possesses high performance in self-cleaning and superhydrophobicity with no need for further hydrophobic modification. Furthermore, the xerogel obtained can find potential applications in absorbents, coatings, and scaffolds.
- 17Kai, D.; Zhang, K.; Jiang, L.; Wong, H. Z.; Li, Z.; Zhang, Z.; Loh, X. J. Sustainable and Antioxidant Lignin–Polyester Copolymers and Nanofibers for Potential Healthcare Applications. ACS Sustainable Chem. Eng. 2017, 5 (7), 6016– 6025, DOI: 10.1021/acssuschemeng.7b00850Google Scholar17https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXosVOqurw%253D&md5=4786bdc2c3d5e3ee4d729ba82bd87589Sustainable and Antioxidant Lignin-Polyester Copolymers and Nanofibers for Potential Healthcare ApplicationsKai, Dan; Zhang, Kangyi; Jiang, Lu; Wong, Hua Zhong; Li, Zibiao; Zhang, Zheng; Loh, Xian JunACS Sustainable Chemistry & Engineering (2017), 5 (7), 6016-6025CODEN: ASCECG; ISSN:2168-0485. (American Chemical Society)Lignin polymn. has been considered as an effective approach for lignin valorization. Herein we report the synthesis of a series of new lignin-based copolymers (lignin-poly(ε-caprolactone-co-lactide), lignin-PCLLA) via solvent-free ring-opening polymn. Lignin-PCLLA copolymers with tunable mol. wts. (10 to 16 kDa) and glass transition temps. (-40 to 40 °C) were obtained. Such copolymers were engineered into ultrafine nanofibers by blending with polyesters (polycaprolactone, PCL and poly(L-lactic acid), PLLA) via electrospinning. Both PCL/lignin-PCLLA and PLLA/lignin-PCLLA nanofibers displayed uniform and beadless nanofibrous morphol. The size (diams. ranging from 300 to 500 nm) and tensile tests of the obtained nanofibers indicated that the lignin copolymers are miscible with the polyester matrixes and can significantly improve the mech. properties of the nanofibers. Moreover, good antioxidant activity and biocompatibility of the lignin nanofibers were demonstrated in vitro, certifying the great potential of lignin-PCLLA copolymers and nanofibers for biomedical or healthcare applications.
- 18Wei, C.; Zhu, X.; Peng, H.; Chen, J.; Zhang, F.; Zhao, Q. Facile Preparation of Lignin-Based Underwater Adhesives with Improved Performances. ACS Sustainable Chem. Eng. 2019, 7 (4), 4508– 4514, DOI: 10.1021/acssuschemeng.8b06731Google Scholar18https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXitlKmsLg%253D&md5=f501a53bfd62f44d0858ed0469ebefc9Facile Preparation of Lignin-Based Underwater Adhesives with Improved PerformancesWei, Congying; Zhu, Xiangwei; Peng, Haiyan; Chen, Jianjun; Zhang, Fang; Zhao, QiangACS Sustainable Chemistry & Engineering (2019), 7 (4), 4508-4514CODEN: ASCECG; ISSN:2168-0485. (American Chemical Society)Bioinspired wet adhesives have demonstrated versatile applicability in humid conditions, but the attainment of catecholic protein mimics comprises multistep synthesis and use of complex chem. components. Advanced wet adhesives derived from inexpensive bioresources and green processing are highly expected. We report a straightforward means to underwater-implemented adhesives from aq. mixing of lignosulfonate (LS) and a polyamidoamine-epichlorohydrin (PAE-Cl) soln. The formation of a fluidic LS-PAE complex was driven by a delicate balance between electrostatic attraction and hydrophilic stabilization. The obtained adhesive highlights instant wet adhesion on diverse submerged surfaces and spontaneous curing in water. More importantly, it demonstrates robust and stable bonding strength over the alkali, salty, high-temp., and long-time soaking conditions. This work advanced the development of lignin into functional wet adhesives through a green and sustainable approach.
- 19Baker, D. A.; Rials, T. G. Recent Advances in Low-Cost Carbon Fiber Manufacture from Lignin. J. Appl. Polym. Sci. 2013, 130 (2), 713– 728, DOI: 10.1002/app.39273Google Scholar19https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXms1OisLg%253D&md5=a04827db94b77c03041c9732f0f591c7Recent advances in low-cost carbon fiber manufacture from ligninBaker, Darren A.; Rials, Timothy G.Journal of Applied Polymer Science (2013), 130 (2), 713-728CODEN: JAPNAB; ISSN:0021-8995. (John Wiley & Sons, Inc.)A review. The confluence of two US energy policy mandates, the 2012 Corporate Av. Fuel Economy Stds. and Renewable Fuels Std. #2, provide the opportunity to examine the possibility of high-value materials from lignin with increased depth. In this case, the desire to provide lighter, low-cost materials for automobiles to reduce fuel consumption, and to improve the economics of biorefineries for fuel prodn., have led to an increased interest in low-cost carbon fiber manuf. from lignin. For this review the authors provide the context of subject matter importance, a cost comparison of potential low-cost carbon fibers, a brief review of historical work, a review of more recent work, and a limited tech. discussion followed by recommendations for future directions. As the available material for review is limited, the author includes many refs. to publicly available government documents and reviewed proceedings that are generally difficult to locate. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 000: 000-000, 2013.
- 20Geng, S.; Wei, J.; Jonasson, S.; Hedlund, J.; Oksman, K. Multifunctional Carbon Aerogels with Hierarchical Anisotropic Structure Derived from Lignin and Cellulose Nanofibers for CO2 Capture and Energy Storage. ACS Appl. Mater. Interfaces 2020, 12 (6), 7432– 7441, DOI: 10.1021/acsami.9b19955Google Scholar20https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXhtlWhurk%253D&md5=a1615e53c2f26c21293e7c17482f2beeMultifunctional Carbon Aerogels with Hierarchical Anisotropic Structure Derived from Lignin and Cellulose Nanofibers for CO2 Capture and Energy StorageGeng, Shiyu; Wei, Jiayuan; Jonasson, Simon; Hedlund, Jonas; Oksman, KristiinaACS Applied Materials & Interfaces (2020), 12 (6), 7432-7441CODEN: AAMICK; ISSN:1944-8244. (American Chemical Society)In current times, CO2 capture and lightwt. energy storage are receiving significant attention and will be vital functions in next-generation materials. Porous carbonaceous materials have great potential in these areas, whereas most of the developed carbon materials still have significant limitations, such as nonrenewable resources, complex and costly processing, or the absence of tailorable structure. In this study, a new strategy is developed for using the currently underutilized lignin and cellulose nanofibers, which can be extd. from renewable resources to produce high-performance multifunctional carbon aerogels with a tailorable, anisotropic pore structure. Both the macro- and microstructure of the carbon aerogels can be simultaneously controlled by carefully tuning the wt. ratio of lignin to cellulose nanofibers in the precursors, which considerably influences their final porosity and surface area. The designed carbon aerogels demonstrate excellent performance in both CO2 capture and capacitive energy storage, and the best results exhibit a CO2 adsorption capacity of 5.23 mmol g-1 at 273 K and 100 kPa and a specific elec. double-layer capacitance of 124 F g-1 at a c.d. of 0.2 A g-1, indicating that they have great future potential in the relevant applications.
- 21Guo, N.; Li, M.; Sun, X.; Wang, F.; Yang, R. Enzymatic Hydrolysis Lignin Derived Hierarchical Porous Carbon for Supercapacitors in Ionic Liquids with High Power and Energy Densities. Green Chem. 2017, 19 (11), 2595– 2602, DOI: 10.1039/C7GC00506GGoogle Scholar21https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXlvFyksLY%253D&md5=757b7deacc069b7b71ed16c0c5eb792dEnzymatic hydrolysis lignin derived hierarchical porous carbon for supercapacitors in ionic liquids with high power and energy densitiesGuo, Nannan; Li, Min; Sun, Xingkai; Wang, Feng; Yang, RuGreen Chemistry (2017), 19 (11), 2595-2602CODEN: GRCHFJ; ISSN:1463-9262. (Royal Society of Chemistry)Porous carbons were obtained by chem. activation of hydrochar, prepd. by hydrothermal carbonization using enzymic hydrolysis lignin originated from the butanol fermn. of corn straw. The intermediate hydrochar was activated using different KOH/hydrochar wt. ratios to evaluate the effect of these ratios on its electrochem. properties. The materials thus prepd. exhibited high sp. surface areas in the range 1290-1660 m2 g-1 mainly attributed to the three-dimensional hierarchical texture made up of abundant micropores, small mesopores and macropores, and high elec. cond. in the 4.0-5.4 S cm-1 range. Consequently, the samples show high specific capacitance, superior rate performance and outstanding durability in three-electrode and two-electrode systems in 6 M KOH. The as-assembled sym. supercapacitor in an ionic liq. electrolyte system exhibits a superior energy d. of 46.8 W h kg-1 and a value of 22.9 W h kg-1 is maintained even at an ultrahigh power d. of 25 400 W kg-1. These materials possessing excellent structural features are an ideal candidate for high performance supercapacitors.
- 22Herou, S.; Ribadeneyra, M. C.; Madhu, R.; Araullo-Peters, V.; Jensen, A.; Schlee, P.; Titirici, M. Ordered Mesoporous Carbons from Lignin: A New Class of Biobased Electrodes for Supercapacitors. Green Chem. 2019, 21 (3), 550– 559, DOI: 10.1039/C8GC03497DGoogle Scholar22https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXkvFSgtg%253D%253D&md5=931b2d91fc1d551b8c16e12a37de0740Ordered mesoporous carbons from lignin: a new class of biobased electrodes for supercapacitorsHerou, Servann; Ribadeneyra, Maria Crespo; Madhu, Rajesh; Araullo-Peters, Vicente; Jensen, Anders; Schlee, Philipp; Titirici, MagdalenaGreen Chemistry (2019), 21 (3), 550-559CODEN: GRCHFJ; ISSN:1463-9262. (Royal Society of Chemistry)We report the synthesis of sustainable ordered mesoporous carbons (OMCs) produced from lignin, using the evapn. induced self-assembly (EISA) method. We demonstrated that it is possible to replace half of the phloroglucinol (a well-known carbon precursor currently not derived from bioprecursors) by hardwood organosolv lignin while obtaining a highly ordered pore structure. Notably, we also used glyoxal instead of formaldehyde as a crosslinker, which makes the synthesis route even "greener" with respect to the toxicity of the precursors and their renewable sourcing. Finally, we demonstrated that the resulting carbons make powerful electrodes in supercapacitors and we have made clear correlations between the porous structure and their electrochem. performance in sym. supercapacitors in order to deliver tailored energy storage to meet various demands (i.e. amt. of charge stored vs. power of delivery).
- 23Baker, D. A.; Gallego, N. C.; Baker, F. S. On the Characterization and Spinning of an Organic-Purified Lignin toward the Manufacture of Low-Cost Carbon Fiber. J. Appl. Polym. Sci. 2012, 124 (1), 227– 234, DOI: 10.1002/app.33596Google Scholar23https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXht1OhsbnE&md5=599787e266c544d07985f495c13b28b4On characterization and spinning of organic-purified lignin toward manufacture of low-cost carbon fiberBaker, Darren A.; Gallego, Nidia C.; Baker, Frederick S.Journal of Applied Polymer Science (2012), 124 (1), 227-234CODEN: JAPNAB; ISSN:0021-8995. (John Wiley & Sons, Inc.)A Kraft hardwood lignin (HWL) and an org.-purified hardwood lignin (HWL-OP) were evaluated as potential precursors for the prodn. of low-cost carbon fibers. It was found that the unpurified HWL exhibited poor spinnability while the HWL-OP exhibited excellent spinnability characteristics. Fibers of various diams. were obtained from the HWL-OP. Thermostabilization studies showed that oxidative stabilization can only be used to convert HWL-OP-based fibers into carbon fibers if extremely low heating rates are applied. Carbonized lignin-based fibers had tensile strength of 0.51 GPa and tensile modulus of 28.6 GPa.
- 24Qu, W.; Liu, J.; Xue, Y.; Wang, X.; Bai, X. Potential of Producing Carbon Fiber from Biorefinery Corn Stover Lignin with High Ash Content. J. Appl. Polym. Sci. 2018, 135 (4), 45736, DOI: 10.1002/app.45736Google ScholarThere is no corresponding record for this reference.
1–11.
- 25Sudo, K.; Shimizu, K. A New Carbon Fiber from Lignin. J. Appl. Polym. Sci. 1992, 44 (1), 127– 134, DOI: 10.1002/app.1992.070440113Google Scholar25https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK38XmsFCgsQ%253D%253D&md5=323428917b7cb0b3c1fa3b504e02d188A new carbon fiber from ligninSudo, K.; Shimizu, K.Journal of Applied Polymer Science (1992), 44 (1), 127-34CODEN: JAPNAB; ISSN:0021-8995.A new C fiber was prepd. from the lignin (steam-exploded lignin), which was isolated from steam-exploded birch wood (Betula platyphylla). The lignin was modified to melt thermally on hydrogenolysis. The chloroform sol. and CS2 insol. fraction (HL) of the reaction products was heated at 300-350° for 30 min, giving a molten viscous material (HHL). The HHL had a softening point of 110° and melted at >145° to form viscous liq. When HHL was subjected to a spinning test, according to a conventional fusion spinning method at a speed >100 m/min, a fine filament could be continuously formed through a pinhole (diam. 0.3 mm). After the filaments were heated in air at 1-2°/min for ≤210°, by which time the filament was converted to have an infusible property, the filaments were carbonized by heating from room temp. to 1000° at a heating rate of 5°/min in a stream of N. The typical properties of the lignin-based C fiber were: fiber diam. 7.6 ±2.7 μm, elongation 1.63 ±0.29%, tensile strength 660 ±230 MPa, modulus of elasticity 40.7 ±6.3 GPa. The chem. structure of the precursor was remarkably changed from that of the original lignin, indicating the elimination of aliph. functional groups implied originally in the starting material.
- 26Uraki, Y.; Kubo, S.; Kurakami, H.; Sano, Y. Activated Carbon Fibers from Acetic Acid Lignin. Holzforschung 1997, 51 (2), 188– 192, DOI: 10.1515/hfsg.1997.51.2.188Google Scholar26https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK2sXltFOqu74%253D&md5=39ac2e32e64ca54f58f273ca16e47eebActivated carbon fibers from acetic acid ligninUraki, Yasumitsu; Kubo, Satoshi; Kurakami, Harutora; Sano, YoshihiroHolzforschung (1997), 51 (2), 188-192CODEN: HOLZAZ; ISSN:0018-3830. (de Gruyter)Activated carbon fibers (ACF's) were prepd. from acetic acid lignin-based carbon fibers by steam activation. The ACF had excellent properties, such as more rapid adsorption rate and higher iodine and methylene blue adsorption capacities, as compared to a com. available activated carbon. The adsorption mechanism of ACF was quite different from that of activated carbon (AC), as supported by the micropore distribution profiles.
- 27Kadla, J.; Kubo, S.; Venditti, R.; Gilbert, R.; Compere, A.; Griffith, W. Lignin-Based Carbon Fibers for Composite Fiber Applications. Carbon 2002, 40 (15), 2913– 2920, DOI: 10.1016/S0008-6223(02)00248-8Google Scholar27https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD38Xot1WmtrY%253D&md5=9be05ea6b16322abcc57eebd45ea66eaLignin-based carbon fibers for composite fiber applicationsKadla, J. F.; Kubo, S.; Venditti, R. A.; Gilbert, R. D.; Compere, A. L.; Griffith, W.Carbon (2002), 40 (15), 2913-2920CODEN: CRBNAH; ISSN:0008-6223. (Elsevier Science Ltd.)Carbon fibers were produced for the first time from a com. available kraft lignin, without any chem. modification, by thermal spinning followed by carbonization. A fusible lignin with excellent spinnability to form a fine filament was produced with a thermal pretreatment under vacuum. Blending the lignin with poly(ethylene oxide) (PEO) further facilitated fiber spinning, but at PEO levels >5%, the blends could not be stabilized without the individual fibers fusing together. The carbon fibers produced had an over all yield of 45%. The tensile strength and modulus increased with decreasing fiber diam., and are comparable to those of much smaller diam. carbon fibers produced from phenolated exploded lignins. In view of the mech. properties, tensile strength 400-550 MPa and elastic modulus 30-60 GPa, kraft lignin should be further investigated as a precursor for general grade carbon fibers.
- 28Pandolfo, T.; Ruiz, V.; Seepalakottai, S.; Nerkar, J. Ch 2. General Properties of Electrochemical Capacitors. In Supercapacitors: Materials, Systems, and Applications; Lu, M., Ed.; Wiley-VCH Verlag GmbH & Co.: Weinheim, Germany, 2013; pp 69– 110.Google ScholarThere is no corresponding record for this reference.
- 29Wei, J.; Geng, S.; Pitkänen, O.; Jarvinen, T.; Kordas, K.; Oksman, K. Green Carbon Nanofiber Networks for Advanced Energy Storage. ACS Applied Energy Materials 2020, 3 (4), 3530– 3540, DOI: 10.1021/acsaem.0c00065Google Scholar29https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXmt1eqtbo%253D&md5=b5c96368b128d74909e7a80368646f1bGreen Carbon Nanofiber Networks for Advanced Energy StorageWei, Jiayuan; Geng, Shiyu; Pitkaenen, Olli; Jaervinen, Topias; Kordas, Krisztian; Oksman, KristiinaACS Applied Energy Materials (2020), 3 (4), 3530-3540CODEN: AAEMCQ; ISSN:2574-0962. (American Chemical Society)Energy storage devices such as supercapacitors of high performance are in great need due to the continuous expansion of digitalization and related devices for mobile electronics, autonomous sensors, and vehicles of different kinds. However, the nonrenewable resources and often complex prepn. processes assocd. with electrode materials and structures pose limited scale-up in prodn. and difficulties in versatile utilization of the devices. Here, free-standing and flexible carbon nanofiber networks derived from renewable and abundant bioresources are demonstrated. By a simple optimization of carbonization, the carbon nanofiber networks reach a large surface area of 1670 m2 g-1 and excellent specific gravimetric capacitance of ~ 240 F g-1, outperforming many other nanostructured carbon, activated carbon, and even those decorated with metal oxides. The remarkable electrochem. performance and flexibility of the green carbon networks enable an all-solid-state supercapacitor device, which displays a device capacitance of 60.4 F g-1 with a corresponding gravimetric energy d. of 8.4 Wh kg-1 while maintaining good mech. properties.
- 30Lai, C.; Zhou, Z.; Zhang, L.; Wang, X.; Zhou, Q.; Zhao, Y.; Wang, Y.; Wu, X.-F.; Zhu, Z.; Fong, H. Free-Standing and Mechanically Flexible Mats Consisting of Electrospun Carbon Nanofibers Made from a Natural Product of Alkali Lignin as Binder-Free Electrodes for High-Performance Supercapacitors. J. Power Sources 2014, 247, 134– 141, DOI: 10.1016/j.jpowsour.2013.08.082Google Scholar30https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhs12lu7%252FE&md5=5424be2b998f439d74ededbb8eba9c16Free-standing and mechanically flexible mats consisting of electrospun carbon nanofibers made from a natural product of alkali lignin as binder-free electrodes for high-performance supercapacitorsLai, Chuilin; Zhou, Zhengping; Zhang, Lifeng; Wang, Xiaoxu; Zhou, Qixin; Zhao, Yong; Wang, Yechun; Wu, Xiang-Fa; Zhu, Zhengtao; Fong, HaoJournal of Power Sources (2014), 247 (), 134-141CODEN: JPSODZ; ISSN:0378-7753. (Elsevier B.V.)Mech. flexible mats consisting of electrospun carbon nanofibers (ECNFs) were prepd. by first electrospinning aq. mixts. contg. a natural product of alkali lignin together with polyvinyl alc. (PVA) into composite nanofiber mats followed by stabilization in air and carbonization in an inert environment. Morphol. and structural properties, as well as sp. surface area, total pore vol., av. pore size, and pore size distribution, of the lignin-based ECNF mats were characterized; and their electrochem. performances (i.e., capacitive behaviors) were evaluated by cyclic voltammetry, galvanostatic charge/discharge, and electrochem. impedance spectroscopy. The lignin-based ECNF mats exhibited outstanding performance as free-standing and/or binder-free electrodes of supercapacitors. For example, the ECNFs made from the composite nanofibers with mass ratio of lignin/PVA being 70/30 (i.e., ECNFs (70/30)) had the av. diam. of ∼100 nm and the Brunauer-Emmett-Teller (BET) sp. surface area of ∼583 m2.g-1. The gravimetric capacitance of ECNFs (70/30) electrode in 6 M KOH aq. electrolyte exhibited 64 F.g-1 at c.d. of 400 mA.g-1 and 50 F.g-1 at 2000 mA.g-1. The ECNFs (70/30) electrode also exhibited excellent cycling durability/stability, and the gravimetric capacitance merely reduced by ∼10% after 6000 cycles of charge/discharge.
- 31Hu, S.; Zhang, S.; Pan, N.; Hsieh, Y.-L. High Energy Density Supercapacitors from Lignin Derived Submicron Activated Carbon Fibers in Aqueous Electrolytes. J. Power Sources 2014, 270, 106– 112, DOI: 10.1016/j.jpowsour.2014.07.063Google Scholar31https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXht1KgsLfL&md5=26e8a6a19d623c5933a9acc93557651bHigh energy density supercapacitors from lignin derived submicron activated carbon fibers in aqueous electrolytesHu, Sixiao; Zhang, Sanliang; Pan, Ning; Hsieh, You-LoJournal of Power Sources (2014), 270 (), 106-112CODEN: JPSODZ; ISSN:0378-7753. (Elsevier B.V.)Highly porous submicron activated carbon fibers (ACFs) were robustly generated from low sulfonated alkali lignin and fabricated into supercapacitors for capacitive energy storage. The hydrophilic and high sp. surface ACFs exhibited large-size nanographites and good elec. cond. to demonstrate outstanding electrochem. performance. ACFs from KOH activation, in particular, showed very high 344 F g-1 specific capacitance at low 1.8 mg cm-2 mass loading and 10 mV s-1 scan rate in aq. electrolytes. Even at relatively high scan rate of 50 mV s-1 and mass loading of 10 mg cm-2, a decent specific capacitance of 196 F g-1 and a remarkable areal capacitance of 0.55 F cm-2 was obtained, leading to high energy d. of 8.1 Wh kg-1 based on averaged electrodes mass. Furthermore, over 96% capacitance retention rates were achieved after 5000 charge/discharge cycles. Such excellent performance demonstrated great potential of lignin derived carbons for elec. energy storage.
- 32You, X.; Koda, K.; Yamada, T.; Uraki, Y. Preparation of Electrode for Electric Double Layer Capacitor from Electrospun Lignin Fibers. Holzforschung 2015, 69 (9), 1097– 1106, DOI: 10.1515/hf-2014-0262Google Scholar32https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXhslCqsb%252FO&md5=c415b63cff485dd966bf7819ff59ff29Preparation of electrode for electric double layer capacitor from electrospun lignin fibersYou, Xiangyu; Koda, Keiichi; Yamada, Tatsuhiko; Uraki, YasumitsuHolzforschung (2015), 69 (9), 1097-1106CODEN: HOLZAZ; ISSN:0018-3830. (Walter de Gruyter GmbH)Lignin-based activated carbon fibers (ACFs) were prepd. by electrospinning of hardwood acetic acid lignin (HW-AAL) soln. followed by thermostabilization, carbonization, and steam activation. The thermostabilization process was able to be remarkably shortened from 38 h to 3 h with hexamethylenetetramine (hexamine) in binary solvents, AcOH/CCl4 (8/2), when compared with conventional thermostabilization processes. The resultant ACFs possessed higher sp. surface area (2185 m2 g-1) than those from com. activated carbon and electrospun lignin fibers without hexamine. These ACFs also exhibited good elec. capacitance (133.3 F g-1 at a c.d. of 1 A g-1) as electrodes of elec. double layer capacitor (EDLC) are efficient not only due to their large surfaces area but also due to their porous structure with well-developed micropores (diam.: 0.5-1.3 nm). High energy d. and power d. of this EDLC (42 Wh kg-1 and 91 kW kg-1, resp.) were also achieved.
- 33Ma, X.; Kolla, P.; Zhao, Y.; Smirnova, A. L.; Fong, H. Electrospun Lignin-Derived Carbon Nanofiber Mats Surface-Decorated with MnO2 Nanowhiskers as Binder-Free Supercapacitor Electrodes with High Performance. J. Power Sources 2016, 325, 541– 548, DOI: 10.1016/j.jpowsour.2016.06.073Google Scholar33https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC28XhtVGiu73N&md5=3ec17f52f1a2e1425284d6ec843b0c00Electrospun lignin-derived carbon nanofiber mats surface-decorated with MnO2 nanowhiskers as binder-free supercapacitor electrodes with high performanceMa, Xiaojing; Kolla, Praveen; Zhao, Yong; Smirnova, Alevtina L.; Fong, HaoJournal of Power Sources (2016), 325 (), 541-548CODEN: JPSODZ; ISSN:0378-7753. (Elsevier B.V.)The aim of this study is to explore innovative materials for the development of next-generation supercapacitor electrodes. The hypothesis is that, upon the surface-decoration with appropriate amt. of MnO2 nanowhiskers, freestanding and highly graphitic electrospun carbon nanofiber (ECNF) mats (with fiber diams. of ∼200 nm and BET sp. surface areas of ∼583 m2 g-1) derived from a natural product of lignin would be binder-free supercapacitor electrodes with high performance. To test the hypothesis, the ECNF mats have been prepd. first; thereafter, the acquired ECNF mats have been surface-decorated with varied amts. of MnO2 nanowhiskers to prep. three types of ECNF/MnO2 mats. The morphol. and structural properties of ECNF and ECNF/MnO2 mats are characterized by SEM, TEM and XRD, the wt. percentages of MnO2 nanowhiskers in three ECNF/MnO2 mats are detd. by thermal gravimetric anal.; while the electrochem. performance of each mat/electrode is evaluated by cyclic voltammetry, galvanostatic charge/discharge method, and electrochem. impedance spectroscopy. This study reveals that, all of the three ECNF/MnO2 mats/electrodes have significantly enhanced electrochem. performances compared to the ECNF mat/electrode; while the ECNF/MnO2 (1:1) mat/electrode exhibits the highest gravimetric capacitance of 83.3 F g-1, energy d. of 84.3 W h kg-1, and power d. of 5.72 kW kg-1.
- 34Hu, S.; Hsieh, Y.-L. Lignin Derived Activated Carbon Particulates as an Electric Supercapacitor: Carbonization and Activation on Porous Structures and Microstructures. RSC Adv. 2017, 7 (48), 30459– 30468, DOI: 10.1039/C7RA00103GGoogle Scholar34https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXpvVKnur4%253D&md5=0fade3b61f3f681e98bffbf2d609caafLignin derived activated carbon particulates as an electric supercapacitor: carbonization and activation on porous structures and microstructuresHu, Sixiao; Hsieh, You-LoRSC Advances (2017), 7 (48), 30459-30468CODEN: RSCACL; ISSN:2046-2069. (Royal Society of Chemistry)Microporous and mesoporous particulate activated carbons (PACs) with unique hierarchical microstructures were facilely synthesized from alkali lignin via simultaneous carbonization and alkali hydroxide activation. Both NaOH and KOH activated PACs contained slit-like micropores and carbon microstructures with circular nanoplates of graphite-like basal planes and amorphous carbon clusters. The micropores broadened with increasing temps., holding time and alk. hydroxides. The basal planes sizes and order were enhanced with increasing temps. and holding time but lowering impregnation ratios, while amorphous carbon showed no particular patterns due to its much higher reactivity toward alkali hydroxides. The PACs with the highest micropore surface area and pore vol. (1100 m2 g-1, 0.43 cm3 g-1) were obtained at 900°C, 30 min and an impregnation ratio of 1 and fabricated into elec. supercapacitors to exhibit excellent 226 F g-1 specific capacitance, 7.8 W h kg-1 energy d. and 47 kW kg-1 power d. as well as over 92% capacitance retention after 5000 cycles.
- 35Fang, W.; Yang, S.; Yuan, T.-Q.; Charlton, A.; Sun, R.-C. Effects of Various Surfactants on Alkali Lignin Electrospinning Ability and Spun Fibers. Ind. Eng. Chem. Res. 2017, 56 (34), 9551– 9559, DOI: 10.1021/acs.iecr.7b02494Google Scholar35https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXht12mtLnN&md5=66a019f7c44312a6936bcca94d50a3ffEffects of Various Surfactants on Alkali Lignin Electrospinning Ability and Spun FibersFang, Wei; Yang, Sen; Yuan, Tong-Qi; Charlton, Adam; Sun, Run-CangIndustrial & Engineering Chemistry Research (2017), 56 (34), 9551-9559CODEN: IECRED; ISSN:0888-5885. (American Chemical Society)Anionic, cationic, and nonionic surfactants with varying concns. (0.2-1.2%) were introduced to neutralize beads on lignin nanofibers by decreasing the surface tension of spinning dopes. The surfactants used in this work were sodium dodecyl sulfate (SDS), N,N,N-trimethyl-1-dodecanaminium bromide (DTAB), and Triton X-100 (TX-100). The effects of viscosity, rheol. properties, surface tension, and cond. of the solns. on the morphol. and physicochem. performances of fibers were investigated. As expected, the presence of certain amts. of surfactants eliminated the beads and resulted in the formation of smooth and bead-free fibers with small diams. Furthermore, the gravimetric capacitance of the carbon mat with 1% SDS was slightly improved from 66.3 to 80.7 F g-1. The results suggested that the surfactants benefit from the electrospinning of lignin and allow for the control over nanofiber morphol. without compromising their performance as supercapacitor electrodes.
- 36Shu, R.; Zhang, Q.; Ma, L.; Xu, Y.; Chen, P.; Wang, C.; Wang, T. Insight into the Solvent, Temperature and Time Effects on the Hydrogenolysis of Hydrolyzed Lignin. Bioresour. Technol. 2016, 221, 568– 575, DOI: 10.1016/j.biortech.2016.09.043Google Scholar36https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC28XhsFamsrbF&md5=9bae3e4108c7a91f522935b169d95a7cInsight into the solvent, temperature and time effects on the hydrogenolysis of hydrolyzed ligninShu, Riyang; Zhang, Qi; Ma, Longlong; Xu, Ying; Chen, Pengru; Wang, Chenguang; Wang, TiejunBioresource Technology (2016), 221 (), 568-575CODEN: BIRTEB; ISSN:0960-8524. (Elsevier Ltd.)The aim of this study is to explore the reaction mediums and conditions for producing high yield of valuable monomers from concd. sulfuric acid hydrolyzed lignin. The solvent, temp. and time effects on the hydrogenolysis of hydrolyzed lignin were investigated under the catalysis of Pd/C and CrCl3. Supercrit. methanol exhibits the best depolymn. performance, because of its unique diffusion, dissoln. and acid-base properties. Afterwards, the influence of reaction temp. and time on depolymn., repolymn. and coking during hydrogenolysis was examd. in methanol. The high temp. is found to favor the depolymn., with the β-O-4 linkages cleaved significantly. However, the repolymn. is promoted simultaneously, and a high amt. of β-β groups form. These reactions are in const. competition with each other and the repolymn. is preferred at excessive high temp., producing bulk char residues, that is coking. This study will provide a beneficial ref. for the maximization of lignin waste valorization.
- 37Cho, J.; Chu, S.; Dauenhauer, P. J.; Huber, G. W. Kinetics and Reaction Chemistry for Slow Pyrolysis of Enzymatic Hydrolysis Lignin and Organosolv Extracted Lignin Derived from Maplewood. Green Chem. 2012, 14 (2), 428– 439, DOI: 10.1039/C1GC16222EGoogle Scholar37https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38Xhsleksbs%253D&md5=09084ee5e9bc9c962f67599e274ec83cKinetics and reaction chemistry for slow pyrolysis of enzymatic hydrolysis lignin and organosolv extracted lignin derived from maplewoodCho, Joungmo; Chu, Sheng; Dauenhauer, Paul J.; Huber, George W.Green Chemistry (2012), 14 (2), 428-439CODEN: GRCHFJ; ISSN:1463-9262. (Royal Society of Chemistry)The kinetics and reaction chem. for the pyrolysis of Maplewood lignin were investigated using both a pyroprobe reactor and a thermogravimetric analyzer mass spectrometry (TGA-MS). Lignin residue after enzymic hydrolysis and organosolv lignin derived from Maplewood were used to measure the kinetic behaviors of lignin pyrolysis and to analyze pyrolysis product distributions. The enzymic lignin residue pyrolyzed at lower temp. than that of organosolv lignin. The differential thermogravimetric (DTG) peaks for pyrolysis of the enzymic residue were more similar to the DTG peaks for pyrolysis of the original Maplewood than DTG of the organosolv lignin. The condensable liq. volatile products were collected from a Pyroprobe reactor with a liq. nitrogen trap. The primary monomeric phenolic compds. were guaiacol, syringol, and vanillic acid. However, only 14-36 carbon% of the sample could be detected by GC-MS. Over 60 carbon% of the condensable products were heavy tar mols. that are not detectable by GC-MS. These heavy tar mols. are the primary products from pyrolysis of lignin. Intermediate solid samples were also collected at various pyrolysis temps. and characterized by elemental anal., FT-IR, DP-MAS 13C NMR, and TOC. The methoxy groups and ether linkages decreased and the non-protonated arom. carbon-carbon bonds increased in the solid residues as the pyrolysis temp. increased. The carbon content of the initial lignin feed (derived from enzymic hydrolysis) and the solid polyaroms. residue (obtained at 773 K) was 58 wt% and 74 wt% resp. This polyarom. residue contained about 69 wt% of the original lignin feed. The solid polyaroms. undergo further slow decompn. accompanied by a const. release of carbon dioxide as the pyrolysis reaction continues. The pyrolysis of the enzymic lignin residue was modelled by two reactions in series. In the first pyrolysis step the lignin was decompd. with an apparent activation energy of 74 kJ mol-1 and a heat of reaction of -8780 kJ kg-1. The second pyrolysis step had an apparent activation energy of 110 kJ mol-1 and a heat of reaction of -2819 kJ kg-1. Lignin pyrolysis has lower activation energies and higher heats of reaction than cellulose pyrolysis.
- 38Ma, R.; Xu, Y.; Zhang, X. Catalytic Oxidation of Biorefinery Lignin to Value-Added Chemicals to Support Sustainable Biofuel Production. ChemSusChem 2015, 8 (1), 24– 51, DOI: 10.1002/cssc.201402503Google Scholar38https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXivVWhuw%253D%253D&md5=85eb71012dd5aa0f7ceb6f6f2250f3beCatalytic Oxidation of Biorefinery Lignin to Value-added Chemicals to Support Sustainable Biofuel ProductionMa, Ruoshui; Xu, Yan; Zhang, XiaoChemSusChem (2015), 8 (1), 24-51CODEN: CHEMIZ; ISSN:1864-5631. (Wiley-VCH Verlag GmbH & Co. KGaA)A review. Transforming plant biomass to biofuel is one of the few solns. that can truly sustain mankind's long-term needs for liq. transportation fuel with minimized environmental impact. However, despite decades of effort, com. development of biomass-to-biofuel conversion processes is still not an economically viable proposition. Identifying value-added co-products along with the prodn. of biofuel provides a key soln. to overcoming this economic barrier. Lignin is the second most abundant component next to cellulose in almost all plant biomass; the emerging biomass refinery industry will inevitably generate an enormous amt. of lignin. Development of selective biorefinery lignin-to-bioproducts conversion processes will play a pivotal role in significantly improving the economic feasibility and sustainability of biofuel prodn. from renewable biomass. The urgency and importance of this endeavor has been increasingly recognized in the last few years. This paper reviews state-of-the-art oxidative lignin depolymn. chemistries employed in the papermaking process and oxidative catalysts that can be applied to biorefinery lignin to produce platform chems. including phenolic compds., dicarboxylic acids, and quinones in high selectivity and yield. The potential synergies of integrating new catalysts with com. delignification chemistries are discussed. We hope the information will build on the existing body of knowledge to provide new insights towards developing practical and com. viable lignin conversion technologies, enabling sustainable biofuel prodn. from lignocellulosic biomass to be competitive with fossil fuel.
- 39Ralph, J.; Landucci, L. L. NMR of Lignins. In Lignin and lignans: Advances in chemistry; Heitner, C., Dimmel, D., Schmidt, J., Eds.; CRC Press (Taylor & Francis Group): Boca Raton, FL, 2010; pp 137– 234.Google ScholarThere is no corresponding record for this reference.
- 40Li, S.; Lundquist, K. A New Method for the Analysis of Phenolic Groups in Lignins by 1H NMR Spectroscopy. Nord. Pulp Pap. Res. J. 1994, 9 (3), 191– 195, DOI: 10.3183/npprj-1994-09-03-p191-195Google Scholar40https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK2MXhsleqtLY%253D&md5=57fd4bdaebe6ffee08d1ffb175557b5cA new method for the analysis of phenolic groups in lignins by proton NMR spectrometryLi, Shiming; Lundquist, KnutNordic Pulp & Paper Research Journal (1994), 9 (3), 191-5CODEN: NPPJEG; ISSN:0283-2631. (Arbor Publishing)Phenolic groups in lignins were analyzed by 1H NMR spectrometry at 400 and 500 MHz (DMSO-d6 soln., temp. 300 K). Under these conditions, the majority of the signals from protons in phenolic OH groups were found in the spectral range δ 8.0-9.3. Most carbonyl-conjugated phenols give signals at δ values >9.3; the corresponding types of lignin units constitute only a very small fraction of the phenolic groups. The no. of phenolic groups in milled wood lignin (MWL) from spruce was estd. as 0.24/phenylpropane unit; phenolic groups in biphenyl and diaryl ether structures constituted about 20% of the total no. of phenolic groups. Spectra of MWL from birch exhibited sep. peaks for phenols in guaiacyl units (δ ≈ 8.8) and syringyl units (δ ≈ 8.2); the total no. of phenolic groups was estd. as 0.18/phenylpropane unit. The proportion of phenols in guaiacyl units was larger than that in syringyl units.
- 41Gil, A.; Lopes, M.; Neto, C. P.; Rocha, J. Very High-Resolution 1H MAS NMR of a Natural Polymeric Material. Solid State Nucl. Magn. Reson. 1999, 15 (1), 59– 67, DOI: 10.1016/S0926-2040(99)00047-8Google Scholar41https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD3cXivVOqtQ%253D%253D&md5=132d43600ba04e410ddd5a4b984fefaaVery high-resolution proton MAS NMR of a natural polymeric materialGil, A. M.; Lopes, M. H.; Pascoal Neto, C.; Rocha, J.Solid State Nuclear Magnetic Resonance (1999), 15 (1), 59-67CODEN: SSNRE4; ISSN:0926-2040. (Elsevier Science B.V.)The use of ultrafast magic angle spinning (> 30 kHz) in tandem with delayed echo acquisition yields very high-resoln. 1H MAS NMR spectra of complex natural org. materials. For the 1st time, very high-resoln. 1H MAS NMR spectra are reported for cork and wood components, 2 natural materials with great economic importance. The effect of the spinning rate on the 1H NMR spectra was evaluated with single-pulse acquisition and delayed-echo acquisition. The delayed-echo acquisition spectra presented line-widths as sharp as 67 and 25 Hz. The narrow peaks, characterized by proton spin-spin and spin-lattice relaxation, were assigned to the isotropic chem. shifts and the general spectral features were shown to correlate with the sample chem. structure. The tentative assignments of cork 1H MAS NMR signals were presented.
- 42Lundquist, K.; Aasen, A. J.; Daasvatn, K.; Forsgren, B.; Gustafsson, J.-A.; Hogberg, B.; Becher, J. NMR Studies of Lignins. 4. Investigation of Spruce Lignin by 1H NMR Spectroscopy. Acta Chem. Scand. 1980, 34b, 21– 26, DOI: 10.3891/acta.chem.scand.34b-0021Google ScholarThere is no corresponding record for this reference.
- 43Chen, C.-L.; Robert, D. Characterization of Lignin by 1H and 13C NMR Spectroscopy. Methods Enzymol. 1988, 161, 137– 174, DOI: 10.1016/0076-6879(88)61017-2Google Scholar43https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaL1MXksF2ktLk%253D&md5=63535665e4b03f3ef1e93a8f48435614Characterization of lignin by proton and carbon-13 NMR spectroscopyChen, Chen Loung; Robert, DanielleMethods in Enzymology (1988), 161 (Biomass, Pt. B), 137-74CODEN: MENZAU; ISSN:0076-6879.A review with 38 refs.
- 44Capanema, E. A.; Balakshin, M. Y.; Kadla, J. F. A Comprehensive Approach for Quantitative Lignin Characterization by NMR Spectroscopy. J. Agric. Food Chem. 2004, 52 (7), 1850– 1860, DOI: 10.1021/jf035282bGoogle Scholar44https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2cXitValsLw%253D&md5=8916836e151a2635b4ec85f012f095a4A Comprehensive Approach for Quantitative Lignin Characterization by NMR SpectroscopyCapanema, Ewellyn A.; Balakshin, Mikhail Y.; Kadla, John F.Journal of Agricultural and Food Chemistry (2004), 52 (7), 1850-1860CODEN: JAFCAU; ISSN:0021-8561. (American Chemical Society)A detailed approach for the quantification of different lignin structures in milled wood lignin (MWL) has been suggested using a combination of NMR techniques. 1H-13C heteronuclear multiple quantum coherence and quant. 13C NMR of nonacetylated and acetylated spruce MWL have been found to have a synergetic effect, resulting in significant progress in the characterization of lignin moieties by NMR. About 80% of side chain moieties, such as different β-O-4, dibenzodioxocin, phenylcoumaran, pinoresinol, and others, have been identified on the structural level. The presence of appreciable amts. of α-O-alkyl and γ-O-alkyl ethers has been suggested. Although the quantification of various condensed moieties was less precise than for side chain structures, reliable information can be obtained. Comparison of the calcd. results with known databases on spruce MWL structure shows that the suggested approach is rather informative and comparable with the information obtained from the combination of various wet chem. methods. Discrepancies between the results obtained in this study and those previously published are discussed.
- 45Chen, C.-L. Characterization of Milled Wood Lignins and Dehydrogenative Polymerisates from Monolignols by Carbon-13 NMR Spectroscopy. ACS Symp. Ser. 1998, 697, 255– 275, DOI: 10.1021/bk-1998-0697.ch018Google Scholar45https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK1cXltlCmsrk%253D&md5=aab00f0ad55999ad6eec3270939930b6Characterization of milled wood lignins and dehydrogenative polymerizates from monolignols by carbon-13 NMR spectroscopyChen, Chen-LoungACS Symposium Series (1998), 697 (Lignin and Lignan Biosynthesis), 255-275CODEN: ACSMC8; ISSN:0097-6156. (American Chemical Society)Carbon-13 NMR spectroscopy was used to characterize milled wood lignin (I) from spruce (Picea glauca) and Zhong-Yan Mu (Bischofia polycarpa), as well as dehydrogenative polymerizates (DHPs) from monolignols. The anal. of a quant. 13C-NMR spectrum of spruce I showed that this guaiacyl type lignin had 8-8', 8-5', 5-5' and 8-O-4' linkages which were interpreted as approximating 2, 9, 24 and 53 per 100 C9-units, resp., whereas the frequency of 7-O-4' linkages was <3 per 100 C9-units. The frequencies of both 5-5' and 8-O-4' linkages were much higher than values previously estd. The spectrum of the Zhong-Yan Mu I showed that it is a guaiacyl-syringyl lignin with a guaiacylpropane-syringylpropane molar ratio of approx. 86:14. The dehydrogenation polymn. of monolignols is discussed on the basis of the components identified among the reaction products.
- 46Hatcher, P. G. Chemical Structural Studies of Natural Lignin by Dipolar Dephasing Solid-State 13C Nuclear Magnetic Resonance. Org. Geochem. 1987, 11 (1), 31– 39, DOI: 10.1016/0146-6380(87)90049-0Google Scholar46https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaL2sXltFOitbk%253D&md5=618d7834274719c46fad8c0d568dc812Chemical structural studies of natural lignin by dipolar dephasing solid-state carbon-13 nuclear magnetic resonanceHatcher, Patrick G.Organic Geochemistry (1987), 11 (1), 31-9CODEN: ORGEDE; ISSN:0146-6380.Lignins from naturally degraded Douglas fir and white oak were examd. by conventional solid-state and dipolar dephasing 13C NMR techniques. The results obtained from both techniques showed that the structure of natural lignins was consistent with models of softwood and hardwood lignin. The dipolar dephasing NMR data provided a measure of the degree of substitution on arom. rings which was consistent with the models.
- 47Sameni, J.; Krigstin, S.; Sain, M. Characterization of Lignins Isolated from Industrial Residues and Their Beneficial Uses. BioResources 2016, 11 (4), 8435– 8456, DOI: 10.15376/biores.11.4.8435-8456Google Scholar47https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXhtlSmsLo%253D&md5=a2adb9ac00976e593b7c7328fdc5bb05Characterization of lignins isolated from industrial residues and their beneficial usesSameni, Javad; Krigstin, Sally; Sain, MohiniBioResources (2016), 11 (4), 8435-8456CODEN: BIORCM; ISSN:1930-2126. (North Carolina State University, Dep. of Wood and Paper Science)The physico-chem. properties of lignin isolated from lignocellulosic bioethanol residues and hardwood kraft black liquor were compared with two com. lignins, kraft softwood lignin, and soda non-wood lignin. Lignin from the industrial residues was isolated through the acid pptn. method. The amt. of lignin isolated was approx. 38% of the dry wt. of lignocellulosic bioethanol residues and approx. 27% of the black liquor solids. The nos. of methoxyl groups and phenolic and aliph. hydroxyls were detd. to derive a mol. formula for each of the four lignins. The mol. wts. of the lignins were measured by high performance size exclusion chromatog. Potential value-added applications of the lignins were summarized based on their mol. wts. and physico-chem. characteristics.
- 48Ferrari, A. C.; Robertson, J. Raman Spectroscopy of Amorphous, Nanostructured, Diamond–like Carbon, and Nanodiamond. Philos. Trans. R. Soc., A 2004, 362 (1824), 2477– 2512, DOI: 10.1098/rsta.2004.1452Google Scholar48https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2cXhtFahtbrM&md5=18ebdb3a57dcbb6b220d0e652345a254Raman spectroscopy of amorphous, nanostructured, diamond-like carbon, and nanodiamondFerrari, Andrea Carlo; Robertson, JohnPhilosophical Transactions of the Royal Society of London, Series A: Mathematical, Physical and Engineering Sciences (2004), 362 (1824), 2477-2512CODEN: PTRMAD; ISSN:1364-503X. (Royal Society)A review. Raman spectroscopy is a std. characterization technique for any C system. Here the authors review the Raman spectra of amorphous, nanostructured, diamond-like C and nanodiamond. To use resonant Raman spectroscopy to det. structure and compn. of C films with and without N. The measured spectra change with varying excitation energy. By visible and UV excitation measurements, the G peak dispersion can be derived and correlated with key parameters; such as d., sp3 content, elastic consts. and chem. compn. The authors then discuss the assignment of the peaks at 1150 and 1480 cm-1 often obsd. in nanodiamond. The authors review the resonant Raman, isotope substitution and annealing expts.; which lead to the assignment of these peaks to trans-polyacetylene.
- 49Ferrari, A. C.; Robertson, J. Interpretation of Raman Spectra of Disordered and Amorphous Carbon. Phys. Rev. B: Condens. Matter Mater. Phys. 2000, 61 (20), 14095– 14107, DOI: 10.1103/PhysRevB.61.14095Google Scholar49https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD3cXjs1Smu7c%253D&md5=e451e6f21e1f6cf375931e6a23e836bbInterpretation of Raman spectra of disordered and amorphous carbonFerrari, A. C.; Robertson, J.Physical Review B: Condensed Matter and Materials Physics (2000), 61 (20), 14095-14107CODEN: PRBMDO; ISSN:0163-1829. (American Physical Society)The model and theor. understanding of the Raman spectra in disordered and amorphous C are given. The nature of the G and D vibration modes in graphite is analyzed in terms of the resonant excitation of π states and the long-range polarizability of π bonding. Visible Raman data on disordered, amorphous, and diamondlike C are classified in a 3-stage model to show the factors that control the position, intensity, and widths of the G and D peaks. The visible Raman spectra depend formally on the configuration of the sp2 sites in sp2-bonded clusters. In cases where the sp2 clustering is controlled by the sp3 fraction, such as in as-deposited tetrahedral amorphous C (ta-C) or hydrogenated amorphous C (a-C:H) films, the visible Raman parameters can be used to derive the sp3 fraction.
- 50Wei, J.; Geng, S.; Kumar, M.; Pitkänen, O.; Hietala, M.; Oksman, K. Investigation of Structure and Chemical Composition of Carbon Nanofibers Developed from Renewable Precursor. Front. Mater. 2019, 6, 334, DOI: 10.3389/fmats.2019.00334Google ScholarThere is no corresponding record for this reference.
- 51Noori, A.; El-Kady, M. F.; Rahmanifar, M. S.; Kaner, R. B.; Mousavi, M. F. Towards Establishing Standard Performance Metrics for Batteries, Supercapacitors and Beyond. Chem. Soc. Rev. 2019, 48 (5), 1272– 1341, DOI: 10.1039/C8CS00581HGoogle Scholar51https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXislCltb8%253D&md5=88f640aa2b5f14f544030014bd4d3666Towards establishing standard performance metrics for batteries, supercapacitors and beyondNoori, Abolhassan; El-Kady, Maher F.; Rahmanifar, Mohammad S.; Kaner, Richard B.; Mousavi, Mir F.Chemical Society Reviews (2019), 48 (5), 1272-1341CODEN: CSRVBR; ISSN:0306-0012. (Royal Society of Chemistry)Over the past decade, electrochem. energy storage (EES) devices have greatly improved, as a wide variety of advanced electrode active materials and new device architectures have been developed. These new materials and devices should be evaluated against clear and rigorous metrics, primarily based on the evidence of real performances. A series of criteria are commonly used to characterize and report performance of EES systems in the literature. However, as advanced EES systems are becoming more and more sophisticated, the methodologies to reliably evaluate the performance of the electrode active materials and EES devices need to be refined to realize the true promise as well as the limitations of these fast-moving technologies, and target areas for further development. In the absence of a commonly accepted core group of metrics, inconsistencies may arise between the values attributed to the materials or devices and their real performances. Herein, we provide an overview of the energy storage devices from conventional capacitors to supercapacitors to hybrid systems and ultimately to batteries. The metrics for evaluation of energy storage systems are described, although the focus is kept on capacitive and hybrid energy storage systems. In addn., we discuss the challenges that still need to be addressed for establishing more sophisticated criteria for evaluating EES systems. We hope this effort will foster ongoing dialog and promote greater understanding of these metrics to develop an international protocol for accurate assessment of EES systems.
- 52Yu, D.; Goh, K.; Wang, H.; Wei, L.; Jiang, W.; Zhang, Q.; Dai, L.; Chen, Y. Scalable Synthesis of Hierarchically Structured Carbon Nanotube–Graphene Fibres for Capacitive Energy Storage. Nat. Nanotechnol. 2014, 9 (7), 555– 562, DOI: 10.1038/nnano.2014.93Google Scholar52https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXnslGksrk%253D&md5=1f3ce86cac98a92bad907cbe87eb5857Scalable synthesis of hierarchically structured carbon nanotube-graphene fibres for capacitive energy storageYu, Dingshan; Goh, Kunli; Wang, Hong; Wei, Li; Jiang, Wenchao; Zhang, Qiang; Dai, Liming; Chen, YuanNature Nanotechnology (2014), 9 (7), 555-562CODEN: NNAABX; ISSN:1748-3387. (Nature Publishing Group)Micro-supercapacitors are promising energy storage devices that can complement or even replace batteries in miniaturized portable electronics and microelectromech. systems. Their main limitation, however, is the low volumetric energy d. when compared with batteries. Here, the authors describe a hierarchically structured carbon microfiber made of an interconnected network of aligned single-walled carbon nanotubes with interposed nitrogen-doped reduced graphene oxide sheets. The nanomaterials form mesoporous structures of large sp. surface area (396 m2 g-1) and high elec. cond. (102 S cm-1). The authors develop a scalable method to continuously produce the fibers using a silica capillary column functioning as a hydrothermal microreactor. The resultant fibers show a sp. volumetric capacity ≤305 F/cm3 in sulfuric acid (measured at 73.5 mA/cm3 in a three-electrode cell) or 300 F/cm3 in polyvinyl alc. (PVA)/H3PO4 electrolyte (measured at 26.7 mA/cm3 in a two-electrode cell). A full micro-supercapacitor with PVA/H3PO4 gel electrolyte, free from binder, current collector and separator, has a volumetric energy d. of ∼6.3 mWh/cm3 (a value comparable to that of 4 V-500 μAh thin-film lithium batteries) while maintaining a power d. more than two orders of magnitude higher than that of batteries, as well as a long cycle life. To demonstrate that the fiber-based, all-solid-state micro-supercapacitors can be easily integrated into miniaturized flexible devices, the authors use them to power an UV photodetector and a light-emitting diode.
- 53Zhu, M.; Liu, H.; Cao, Q.; Zheng, H.; Xu, D.; Guo, H.; Wang, S.; Li, Y.; Zhou, J. Electrospun Lignin-Based Carbon Nanofibers as Supercapacitor Electrodes. ACS Sustainable Chem. Eng. 2020, 8 (34), 12831– 12841, DOI: 10.1021/acssuschemeng.0c03062Google Scholar53https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXhsFWjs7jO&md5=63d73785b01294997c4fdb625b07b70dElectrospun Lignin-Based Carbon Nanofibers as Supercapacitor ElectrodesZhu, Mengni; Liu, Huan; Cao, Qiping; Zheng, Hao; Xu, Dang; Guo, Haoyu; Wang, Shumei; Li, Yao; Zhou, JinghuiACS Sustainable Chemistry & Engineering (2020), 8 (34), 12831-12841CODEN: ASCECG; ISSN:2168-0485. (American Chemical Society)Lignin shows great potential for carbon-based functional materials and composite material electronics. However, high heterogeneity, poor thermal stability, and low mol. wt. limit the practical application of lignin for fiber-shaped lignin-based materials, esp. in the field of supercapacitors with high energy storage devices. Herein, a simple modification and fractionation strategy is designed to obtain lignin for the prepn. of high-performance lignin-based carbon fibers (CFs). The modification and fractionation process effectively increases the mol. wt. and reduces the heterogeneity of lignin. The introduction of lignin with large mol. wt. and low heterogeneity is conducive to reduce the carbon wt. loss of the precursor fibers, maintain the morphol. of lignin-based CFs, and then significantly improve the sp. surface area and energy storage properties. The sp. surface area and energy storage d. of the obtained lignin-based CFs reach 2042.86 m2/g and 442.2 F/g, resp. This strategy provides a simple and effective method for the prepn. of high-performance, low-cost, and green energy storage materials. A simple modification and fractionation strategy is designed to obtain lignin for the prepn. of high-performance lignin-based carbon fibers.
- 54Schlee, P.; Hosseinaei, O.; Baker, D.; Landmér, A.; Tomani, P.; Mostazo-López, M. J.; Cazorla-Amorós, D.; Herou, S.; Titirici, M.-M. From Waste to Wealth: From Kraft Lignin to Free-Standing Supercapacitors. Carbon 2019, 145, 470– 480, DOI: 10.1016/j.carbon.2019.01.035Google Scholar54https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXhvF2gsb4%253D&md5=c8ac50c9fd71df0200cf5f711d88ffbaFrom Waste to Wealth: From Kraft Lignin to Free-standing SupercapacitorsSchlee, Philipp; Hosseinaei, Omid; Baker, Darren; Landmer, Alice; Tomani, Per; Mostazo-Lopez, Maria Jose; Cazorla-Amoros, Diego; Herou, Servann; Titirici, Maria-MagdalenaCarbon (2019), 145 (), 470-480CODEN: CRBNAH; ISSN:0008-6223. (Elsevier Ltd.)Pure eucalyptus Kraft lignin derived carbon fiber mats were produced based on a model work flow. It covers the prepn. and characterization of the lignin precursor and the carbon materials and its testing in the final application (supercapacitor). Sequential solvent extn. was employed to produce a eucalyptus Kraft lignin precursor which could be electrospun into lignin fibers without any additives. The fiber formation from low mol. wt. lignin is assigned to strong intermol. interactions via hydrogen bonding and π-π-stacking between individual lignin macromols. which gives rise to assocn. complexes in the electrospinning soln. By stabilization in air, carbonization in N2 and an activation step in CO2, free-standing microporous carbon fiber mats could be produced. These fiber mats possess mainly basic oxygen functional groups which proved to be beneficial when tested as free-standing electrodes in sym. supercapacitors. Consequently, the CO2-activated fiber mats showed a high specific gravimetric capacitance of 155 F/g at 0.1 A/g, excellent rate capability with 113 F/g at 250 A/g and good capacitance retention of 94% after 6000 cycles when tested in 6 M KOH electrolyte. Therefore, we conclude that lignin itself is a promising precursor to produce microporous, oxygen functionalized carbon fibers serving as free-standing electrodes in aq. supercapacitors.
- 55Ma, C.; Wu, L.; Dirican, M.; Cheng, H.; Li, J.; Song, Y.; Shi, J.; Zhang, X. ZnO-Assisted Synthesis of Lignin-Based Ultra-Fine Microporous Carbon Nanofibers for Supercapacitors. J. Colloid Interface Sci. 2021, 586, 412– 422, DOI: 10.1016/j.jcis.2020.10.105Google Scholar55https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXitlWmt7zJ&md5=922e784fbf32bf7d947901000345bdacZnO-assisted synthesis of lignin-based ultra-fine microporous carbon nanofibers for supercapacitorsMa, Chang; Wu, Liqiang; Dirican, Mahmut; Cheng, Hui; Li, Junjing; Song, Yan; Shi, Jingli; Zhang, XiangwuJournal of Colloid and Interface Science (2021), 586 (), 412-422CODEN: JCISA5; ISSN:0021-9797. (Elsevier B.V.)Reducing the material size could be an effective approach to enhance the electrochem. performance of porous carbons for supercapacitors. In this work, ultra-fine porous carbon nanofibers are prepd. by electrospinning using lignin/ polyvinylpyrrolidone as carbon precursor and zinc nitrate hexahydrate (ZNH) as an additive, followed by pre-oxidn., carbonization, and pickling processes. Assisted by the ZnO template, the pyrolytic product of ZNH, abundant micropores are yielded, leading to the formation of microporous carbon nanofibers with sp. surface area (SSA) up to 1363 m2 g-1. The av. diam. of the lignin-based ultra-fine porous carbon nanofibers (LUPCFs) is effectively controlled from 209 to 83 nm through adjusting the ZNH content. With good flexibility and self-standing nature, the LUPCFs could be directly cut into electrodes for use in supercapacitors. High accessible surface, enriched surface N/O groups, and reduced fiber diams. endow the LUPCFs-based electrodes with an excellent specific capacitance of 289 F g-1. The redn. of fiber diams. remarkably improves the rate performance of the LUPCFs and leads to a low relaxation time const. of 0.37 s. The high specific capacitance of 162 F g-1 is maintained when the c.d. is increased from 0.1 to 20 A g-1. Besides, the fabricated LUPCFs show exceptional cycling stability in sym. supercapacitors, manifesting a promising application prospect in the next generation of supercapacitors.
- 56Xuan, D.; Liu, J.; Wang, D.; Lu, Z.; Liu, Q.; Liu, Y.; Li, S.; Zheng, Z. Facile Preparation of Low-Cost and Cross-Linked Carbon Nanofibers Derived from PAN/PMMA/Lignin as Supercapacitor Electrodes. Energy Fuels 2021, 35 (1), 796– 805, DOI: 10.1021/acs.energyfuels.0c02511Google Scholar56https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXisFWqtr3L&md5=eea73787eb39e90265f204f3a1452205Facile Preparation of Low-Cost and Cross-Linked Carbon Nanofibers Derived from PAN/PMMA/Lignin as Supercapacitor ElectrodesXuan, Dipan; Liu, Jie; Wang, Dechao; Lu, Zhe; Liu, Qian; Liu, Yuxuan; Li, Shuirong; Zheng, ZhifengEnergy & Fuels (2021), 35 (1), 796-805CODEN: ENFUEM; ISSN:0887-0624. (American Chemical Society)To develop economical and high-performance water electrolyte supercapacitor electrodes, low-cost and cross-linked carbon nanofibers (CNFs) were prepd. with an electrospinning method by using PAN, lignin, and PMMA as precursors. The addn. of lignin not only reduces the cost of the carbon nanofibers but also increases the sp. surface area of the CNFs by removing carbonyls, and phenol functional groups of lignin during thermal treatment. The effect of PMMA addn. was investigated to prep. the optimal candidate for the supercapacitor electrodes. The results showed that the CNFs from PAN, PMMA, and lignin (PPLCNFs-x, x is the content of PMMA in the spinning soln.) showed excellent electrochem. performance in alk. aq. electrolyte. PPLCNFs-0.5g showed specific capacitance of 233 F g1- at 0.5 A g-1, an outstanding stability of 96.8% when it was cycled 50 000 times at 2 A g-1, and it remained 54.5% of rate capability as c.d. raising from 0.5 to 100 A g-1. The outstanding electrochem. performance of PPLCNFs-0.5g is expected as a consequence of the synergistic effect of larger sp. surface area and cross-linked structure. The cross-linked structure ensures rapid transmission of electrons on the carbon nanofiber membrane, and the large sp. surface area is conducive to charge storage. This method offers a new prepn. approach for synthesizing high performance CNFs with low-cost, cross-linked structures.
- 57Kim, M.; Kim, Y.; Lee, K. M.; Jeong, S. Y.; Lee, E.; Baeck, S. H.; Shim, S. E. Electrochemical Improvement Due to Alignment of Carbon Nanofibers Fabricated by Electrospinning as an Electrode for Supercapacitor. Carbon 2016, 99, 607– 618, DOI: 10.1016/j.carbon.2015.12.068Google Scholar57https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC28XhsFaksQ%253D%253D&md5=c7fd76cb84612c8394407f51eb05a332Electrochemical improvement due to alignment of carbon nanofibers fabricated by electrospinning as an electrode for supercapacitorKim, Minjae; Kim, Yeongseon; Lee, Kyung Min; Jeong, Seon Young; Lee, Eunsoo; Baeck, Sung Hyeon; Shim, Sang EunCarbon (2016), 99 (), 607-618CODEN: CRBNAH; ISSN:0008-6223. (Elsevier Ltd.)Aligned carbon nanofibers (CNFs) were fabricated by electrospinning to evaluate the potential of aligned one-dimensional structure as a supercapacitor electrode. First, randomly oriented polyacrylonitrile (PAN) nanofibers were fabricated, and aligned PAN nanofibers were prepd. by increasing the speed of the rotary collector from 250 to 2000 rpm. The prepd. PAN nanofibers were carbonized for use as a supercapacitor electrode. According to increase of speed of collector, the sp. surface area and elec. cond. were improved from 533 to 635 m2 g-1 and from 342 to 626 S cm-1, resp. This result might be caused by increased pulling strength between the fibers and the surface of the collector generated by electrospinning as well as the unique aligned nanostructure of CNFs. The specific capacitance and rate capability of the aligned carbon nanofibers (CNFs) were increased by 35.5 and 28.4%, resp., compared to the randomly oriented CNFs. The enhanced surface area, micropore vol. (from 0.19 to 0.24 cm3 g-1), mesopore vol. (from 0.08 to 0.26 cm3 g-1), and aligned structure make an impact upon the unique electrochem. properties both low scan rate (10 mV s-1) and high scan rate (50 mV s-1).
- 58Jia, K.; Zhuang, X.; Cheng, B.; Shi, S.; Shi, Z.; Zhang, B. Solution Blown Aligned Carbon Nanofiber Yarn as Supercapacitor Electrode. J. Mater. Sci.: Mater. Electron. 2013, 24 (12), 4769– 4773, DOI: 10.1007/s10854-013-1472-zGoogle Scholar58https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhtlGqsLzL&md5=801a34635c3681d3f6ff113672dd4f0aSolution blown aligned carbon nanofiber yarn as supercapacitor electrodeJia, Kaifei; Zhuang, Xupin; Cheng, Bowen; Shi, Shaojun; Shi, Zhiqiang; Zhang, BoJournal of Materials Science: Materials in Electronics (2013), 24 (12), 4769-4773CODEN: JSMEEV; ISSN:0957-4522. (Springer)Carbon materials with various microtextures and wide availabilities represent very attractive electrode materials for supercapacitors. In this paper, a modified soln. blowing process, using a pair of parallel rods as collector, was reported to fabricate carbon nanofiber yarn (CNFY) with polyacrylonitrile (PAN) as precursor polymer. The morphol. and structure of the nanofibers were investigated. The PAN precursor and carbon nanofibers were well-aligned and their av. diam. was 280 nm and 187 nm, resp. The performance of CNFY as supercapacitor electrode was evaluated. The CNFY possessed high cond. of 608.7 Scm-1 and mass specific capacitance of 70 Fg-1 at the c.d. of 500 mAg-1, and the redn. of capacitance is 29.14 % of the initial value at the c.d. range from 0.5 to 8 Ag-1. The superior performance of the CNFY electrode was attributed to the well-aligned structure and high elec. cond. which afforded the potential application as a novel electrode for supercapacitors.
- 59Zhang, Z.; Bai, B.; Zeng, L.; Wei, L.; Zhao, T. Aligned Electrospun Carbon Nanofibers as Electrodes for Vanadium Redox Flow Batteries. Energy Technol. 2019, 7 (10), 1900488, DOI: 10.1002/ente.201900488Google Scholar59https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXhvVylsrfO&md5=a51965c34b3b8fe691760376ee00cce8Aligned Electrospun Carbon Nanofibers as Electrodes for Vanadium Redox Flow BatteriesZhang, Zhihui; Bai, Bofeng; Zeng, Lin; Wei, Lei; Zhao, TianshouEnergy Technology (Weinheim, Germany) (2019), 7 (10), 1900488CODEN: ETNEFN; ISSN:2194-4296. (Wiley-VCH Verlag GmbH & Co. KGaA)Electrospun carbon nanofibers (CNFs) are regarded as potential electrode materials for vanadium redox flow batteries (VRFBs) due to the advantages of a large surface area and good electrochem. activity. However, woven CNFs with randomly distributed fibers are limited by poor permeability of the electrolyte, thus leading to a large mass-transport polarization during battery operation. To address this issue, aligned carbon nanofiber (ACNF) webs are fabricated and applied in the battery with fibers parallel to the flow channel. Cyclic voltammogram results show that the as-prepd. aligned electrode exhibits better electrochem. activity for both the VO2+/VO2+ and V2+/V3+ redox reactions than that of com. carbon paper (CP) and random electrodes, attributing to its higher surface area and favorable surface activity. The battery with the ACNF electrode achieves higher voltage efficiency (87%, 60 mA cm-2) than that of CP and random electrodes. Moreover, the ordered structure of the aligned electrode further enhances mass transport effectively, thus lowering the concn. loss. The polarization curve measurements also show that the limiting c.d. of the aligned electrode is 25% higher than that of the random electrode. All these results demonstrate that the aligned electrode is promising in VRFBs.
- 60Zhang, Y.; Song, X.; Xu, Y.; Shen, H.; Kong, X.; Xu, H. Utilization of Wheat Bran for Producing Activated Carbon with High Specific Surface Area via NaOH Activation Using Industrial Furnace. J. Cleaner Prod. 2019, 210, 366– 375, DOI: 10.1016/j.jclepro.2018.11.041Google Scholar60https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1cXit1WlsrvJ&md5=b63d1ba9bb71f450de968ec6cf769c3cUtilization of wheat bran for producing activated carbon with high specific surface area via NaOH activation using industrial furnaceZhang, Ying; Song, Xiaolan; Xu, Yue; Shen, Haijing; Kong, Xiaodong; Xu, HongmeiJournal of Cleaner Production (2019), 210 (), 366-375CODEN: JCROE8; ISSN:0959-6526. (Elsevier Ltd.)Waste of wheat bran was used for the first time to prep. activated carbon with high sp. surface area via sodium hydroxide activation. The effects of activation temp. (700-900°C) and NaOH mass ratio (1-5) on surface area were studied. Products were characterized by thermal anal., nitrogen adsorption-desorption, X-ray diffraction, IR spectroscopy, SEM and transmission electron microscopy. One development model was used to explain the evolution of pore structure. The product synthesized at 800°C with mass ratio of 4 possessed the largest surface area of 2543 ± 89 m2/g with low ash content of 0.68 ± 0.03 wt%. For liq. adsorption of methylene blue, the max. adsorption capacity was recorded as 887.3 ± 24.9 mg/g, higher than 663.8 ± 14.8 mg/g for com. coconut shell carbon. Adsorption data were fitted well with the Redlich-Peterson isotherm and pseudo-second order model, closing to surface area. Cost of carbon prodn. using industrial furnace was calcd. as 3.56 ± 0.18 $/kg (reduced 32.4% than tube furnace), with output of 1.28 ± 0.07 kg/d (improved 11.8 times). It could be demonstrated that wheat bran was an effective and sustainable raw material to obtain low cost carbon product with high surface area, indicating its potential utilization.
- 61Carrott, P.; Carrott, M. R.; Suhas Comparison of the Dubinin–Radushkevich and Quenched Solid Density Functional Theory Approaches for the Characterisation of Narrow Microporosity in Activated Carbons Obtained by Chemical Activation with KOH or NaOH of Kraft and Hydrolytic Lignins. Carbon 2010, 48 (14), 4162– 4169, DOI: 10.1016/j.carbon.2010.07.031Google Scholar61https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXhtVyru7zL&md5=5903eb0b591fb30b57d0e7a06d45b74eComparison of the Dubinin-Radushkevich and Quenched Solid Density Functional Theory approaches for the characterisation of narrow microporosity in activated carbons obtained by chemical activation with KOH or NaOH of Kraft and hydrolytic ligninsCarrott, P. J. M.; Ribeiro Carrott, M. M. L.; SuhasCarbon (2010), 48 (14), 4162-4169CODEN: CRBNAH; ISSN:0008-6223. (Elsevier Ltd.)The classical DR method and the Quenched Solid D. Functional Theory (QSDFT) approach have been used to analyze N2 at 77 K isotherms detd. on activated carbons prepd. by alk. chem. activation of different lignins. The QSDFT pore size distributions are bimodal with a narrow peak below 1 nm and a broad peak from 1 to 2.5-3.5 nm. Deconvolution allows estn. of the vols. and widths of the narrow micropores. These are lower than estd. by the DR anal. as this does not sep. micropore and non-micropore adsorption. On the basis of the QSDFT anal., the optimum conditions for obtaining materials with a high vol. of narrow micropores were activation temps. of 550-650 °C, hydroxide/lignin ratio of 1 and dwell time at the max. activation temp. of 30 min. KOH was preferable to NaOH as it requires lower temps. and results in materials with higher narrow micropore vols. The "best" material obtained, prepd. with KOH at 550 °C, had mean micropore width of 0.7 nm and micropore vol. of 0.37 cm3 g-1 which compares very favorably with mol. sieve carbons prepd. from synthetic polymers. Furthermore, this material was obtained with an activation yield of 32.9%, which is quite high for alk. chem. activation.
- 62Ago, M.; Jakes, J. E.; Johansson, L.-S.; Park, S.; Rojas, O. J. Interfacial Properties of Lignin-Based Electrospun Nanofibers and Films Reinforced with Cellulose Nanocrystals. ACS Appl. Mater. Interfaces 2012, 4 (12), 6849– 6856, DOI: 10.1021/am302008pGoogle Scholar62https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XhsleqtLfP&md5=1404b05d86e59f1f0a9d2d2f821e601aInterfacial Properties of Lignin-Based Electrospun Nanofibers and Films Reinforced with Cellulose NanocrystalsAgo, Mariko; Jakes, Joseph E.; Johansson, Leena-Sisko; Park, Sunkyu; Rojas, Orlando J.ACS Applied Materials & Interfaces (2012), 4 (12), 6849-6856CODEN: AAMICK; ISSN:1944-8244. (American Chemical Society)Sub-100 nm resoln. local thermal anal., XPS, and water contact angle (WCA) measurements were used to relate surface polymer distribution with the compn. of electrospun fiber mats and spin coated films obtained from aq. dispersions of lignin, polyvinyl alc. (PVA), and cellulose nanocrystal (CNC). Defect-free lignin/PVA fibers were produced with radii which were obsd. to increase with lignin concn. and with the addn. of CNCs. XPS and WCA results indicate a nonlinear relationship between the surface and the bulk compns. A threshold around 50 wt % bulk compn. was identified in which extensive partitioning of PVA and lignin components occurred on the surface below and above this value. In 75:25 wt % lignin/PVA solvent cast films, phase sepd. domains were obsd. Using nanoscale thermal analyses, the continuous phase was detd. to be lignin-rich and the discontinuous phase had a lignin/PVA dispersion. Importantly, the size of the phase sepd. domains was reduced by the addn. of CNCs. When electrospun fiber surfaces were lignin-rich, the addn. of CNCs affected their surfaces. In contrast, no surface effects were obsd. with the addn. of CNCs in PVA-rich fibers. Overall, we highlight the importance of mol. interactions and phase sepn. on the surface properties of fibers from lignin as an abundant raw material for the fabrication of new functional materials.
- 63Bennett, A. E.; Rienstra, C. M.; Auger, M.; Lakshmi, K.; Griffin, R. G. Heteronuclear Decoupling in Rotating Solids. J. Chem. Phys. 1995, 103 (16), 6951– 6958, DOI: 10.1063/1.470372Google Scholar63https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK2MXovVeqtLs%253D&md5=ed2b1421bea9403a0dc85d2f51c8a746Heteronuclear decoupling in rotating solidsBennett, Andrew E.; Rienstra, Chad M.; Auger, Michele; Lakshmi, K. V.; Griffin, Robert G.Journal of Chemical Physics (1995), 103 (16), 6951-8CODEN: JCPSA6; ISSN:0021-9606. (American Institute of Physics)A simple two pulse phase modulation (TPPM) scheme greatly reduces the residual linewidths arising from insufficient proton decoupling power in double resonance magic angle spinning (MAS) expts. Optimization of pulse lengths and phases in the sequence produces substantial improvements in both the resoln. and sensitivity of dil. spins (e.g., 13C) over a broad range of spinning speeds at high magnetic field. The theor. complications introduced by large homo- and heteronuclear interactions among the spins, as well as the amplitude modulation imposed by MAS, are explored anal. and numerically. To the authors' knowledge, this method is the 1st phase-switched sequence to exhibit improvement over continuous-wave (cw) decoupling in a strongly coupled homogeneous spin system undergoing sample spinning.
- 64Earl, W. L.; VanderHart, D. Measurement of 13C Chemical Shifts in Solids. J. Magn. Reson. 1982, 48 (1), 35– 54, DOI: 10.1016/0022-2364(82)90236-0Google Scholar64https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaL38XktFGqsb4%253D&md5=082b8ac5b581e0a46c38496d462434d2Measurement of carbon-13 chemical shifts in solidsEarl, William L.; Van der Hart, D. L.Journal of Magnetic Resonance (1969-1992) (1982), 48 (1), 35-54CODEN: JOMRA4; ISSN:0022-2364.A pulse sequence and sample geometry which allows the measurement of 13C chem. shifts of solid materials relative to liq. Me4Si (TMS) are described. The chem. shifts of a series of common engineering plastics were measured. A small no. of candidate secondary shift ref. materials were considered and their chem. shifts measured. Most of these materials proved to be unsuitable for general 13C shift refs. for differing reasons. The most promising std. investigated was polydimethylsilane. The measurement of chem. shifts in solid materials is slightly complicated by anisotropic magnetic properties and sensitivity to magic-angle missetting when the material exhibits macroscopic orientation. These complications are discussed in detail and examples of misleading spectra are shown.
- 65Morcombe, C. R.; Zilm, K. W. Chemical Shift Referencing in MAS Solid State NMR. J. Magn. Reson. 2003, 162 (2), 479– 486, DOI: 10.1016/S1090-7807(03)00082-XGoogle Scholar65https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD3sXks1Wgtrw%253D&md5=7c8d952460e414150384534810791514Chemical shift referencing in MAS solid state NMRMorcombe, Corey R.; Zilm, Kurt W.Journal of Magnetic Resonance (2003), 162 (2), 479-486CODEN: JMARF3; ISSN:1090-7807. (Elsevier Science)Solid state 13C magic angle spinning (MAS) NMR spectra are typically referenced externally using a probe which does not incorporate a field frequency lock. Soln. NMR shifts however, are more often detd. with respect to an internal ref. and using a deuterium based field frequency lock. Further differences arise in soln. NMR of proteins and nucleic acids where both 13C and 1H shifts are referenced by recording the frequency of the 1H resonance of DSS (sodium salt of 2,2-dimethyl-2-silapentane-5-sulfonic acid) instead of TMS (tetramethylsilane). The authors study the difficulties in relating shifts measured relative to TMS and DSS by these various approaches in soln. and solids NMR, and calibrate adamantane as an external 13C std. for solids NMR. External chem. shift referencing of magic angle spinning spectra is typically quite reproducible and accurate, with better than ±0.03 ppm accuracy being straight forward to achieve. Solid state and liq. phase NMR shifts obtained by magic angle spinning with external referencing agree with those measured using typical soln. NMR hardware with the sample tube aligned with the applied field as long as magnetic susceptibility corrections and solvent shifts are taken into account. The DSS and TMS ref. scales for 13C and 1H are related accurately using MAS NMR. Large solvent shifts for the 13C resonance in TMS in either deuterochloroform or methanol are obsd., being +0.71 ppm and -0.74 ppm from external TMS, resp. The ratio of the 13C resonance frequencies for the two carbons in solid adamantane to the 1H resonance of TMS is reported.
- 66Schneider, C. A.; Rasband, W. S.; Eliceiri, K. W. NIH Image to ImageJ: 25 Years of Image Analysis. Nat. Methods 2012, 9 (7), 671– 675, DOI: 10.1038/nmeth.2089Google Scholar66https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XhtVKntb7P&md5=85ab928cd79f1e2f2351c834c0c600f0NIH Image to ImageJ: 25 years of image analysisSchneider, Caroline A.; Rasband, Wayne S.; Eliceiri, Kevin W.Nature Methods (2012), 9 (7_part1), 671-675CODEN: NMAEA3; ISSN:1548-7091. (Nature Publishing Group)For the past 25 years NIH Image and ImageJ software have been pioneers as open tools for the anal. of scientific images. We discuss the origins, challenges and solns. of these two programs, and how their history can serve to advise and inform other software projects.
- 67Püspöki, Z.; Storath, M.; Sage, D.; Unser, M. Transforms and Operators for Directional Bioimage Analysis: A Survey. In Focus on Bio-Image Informatics; De Vos, W. H., Munck, S., Timmermans, J.-P., Eds.; Advances in Anatomy, Embryology and Cell Biology; Springer International Publishing: New York, 2016; Vol. 219, pp 69– 93.Google ScholarThere is no corresponding record for this reference.
- 68Lundahl, M. J.; Cunha, A. G.; Rojo, E.; Papageorgiou, A. C.; Rautkari, L.; Arboleda, J. C.; Rojas, O. J. Strength and Water Interactions of Cellulose I Filaments Wet-Spun from Cellulose Nanofibril Hydrogels. Sci. Rep. 2016, 6 (1), 1– 13, DOI: 10.1038/srep30695Google ScholarThere is no corresponding record for this reference.
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Abstract
Figure 1
Figure 1. (a) 400.27 MHz 1H NMR spectra of LB, KR, HY, and SD dissolved in DMSO-d6. The 1H NMR resonance line at 2.50 ppm present in all the spectra corresponds to the solvent DMSO-d5(H). Assignment of protons in (i) CH2, CH3; (ii) CH2, CH; (iii) CH, CH3O, CH2O, CHO; (iv) aromatic H; (v) aromatic OH; and (vi) COOH. (b) 100.64 MHz 13C CP-MAS NMR spectra of LB, KR, HY, and SD. The MAS frequency was 8 kHz.
Figure 2
Figure 2. Thermogravimetric analysis of LB, KR, HY, and SD in N2 atmosphere.
Figure 3
Figure 3. Optical microscopy image of the (a) LB, (b) KR, (c) HY, and (d) SD solutions used for preparing the electrospinning precursor.
Figure 4
Figure 4. SEM images and the fiber diameter distributions of (a) C-LB200, (b) C-KR200, (c) C-HY200, and (d) C-SD200.
Figure 5
Figure 5. Orientation-related colored SEM images of (a) C-LB200, (b) C-KR200, (c) C-HY200, and (d) C-SD200. Zero degree corresponds to the vertical direction.
Figure 6
Figure 6. Raman spectra of C-LB200, C-KR200, C-HY200, and C-SD200.
Figure 7
Figure 7. Electrochemical properties of the randomly oriented CFNs. (a) Cyclic voltammograms (CV) of C-LB200, C-KR200, C-HY200, and C-SD200 under a scan rate of 100 mV s–1. (b) Galvanostatic charge–discharge (GCD) profiles of C-LB200, C-KR200, C-HY200, and C-SD200 using a current density of 10 A g–1. (c) Summary of the specific capacitance of C-LB200, C-KR200, C-HY200, and C-SD200 from the GCD under a series of current density. (d) Capacitance retention of C-LB200, C-KR200, C-HY200, and C-SD200 during 10 000 charge–discharge cycles under a current density of 10 A g–1.
Figure 8
Figure 8. Fiber morphology of the as-spun and the carbonized fiber networks. (a) SEM image of LB200, (b) SEM image of LB1500, (c) fiber diameter distribution of LB200 and LB1500, (d) SEM image of C-LB200, (e) SEM image of C-LB1500, and (f) fiber diameter distribution of C-LB200 and C-LB1500.
Figure 9
Figure 9. Orientation-related colored SEM images of (a) LB200, (b) LB-1500, (d) C-LB200, and (e) C-LB1500. Orientation distribution graphs of (c) LB200 and LB1500 and (f) C-LB200 and C-LB1500. Zero degree is aligned to the vertical direction.
Figure 10
Figure 10. Comparison of the electrochemical properties between the randomly oriented and highly oriented CFNs. (a) CV of C-LB1500. (b) GCD of C-LB1500. (c) CV of C-LB200 and C-LB1500 under a scan rate of 100 mV s–1. (d) GCD curves of C-LB200 and C-LB1500 using a current density of 10 A g–1. (e) Summary of the specific capacitance of C-LB200 and C-LB1500 from the GCD under a series of current densities. (f) Capacitance retention of C-LB200 and C-LB1500 during charge–discharge cycles under a current density of 10 A g–1.
Figure 11
Figure 11. Nyquist diagrams for C-LB200 and C-LB1500 obtained using electrochemical impedance spectroscopy (EIS). The testing potential is 300 mV.
References
This article references 68 other publications.
- 1Bajpai, P. Lignin. In Carbon Fibre from Lignin; Springer Nature: Singapore, 2017; pp 11– 15.There is no corresponding record for this reference.
- 2Henriksson, G. Lignin. In Wood chemistry and biotechnology; Ek, M., Gellerstedt, G., Henriksson, G., Eds.; Pulp and Paper Chemistry and Technology; Walter de Gruyter GmbH & Co.: Berlin, Germany, 2009; Vol. 1, pp 121– 145.There is no corresponding record for this reference.
- 3Yuan, T.-Q.; Sun, S.-N.; Xu, F.; Sun, R.-C. Characterization of Lignin Structures and Lignin–Carbohydrate Complex (LCC) Linkages by Quantitative 13C and 2D HSQC NMR Spectroscopy. J. Agric. Food Chem. 2011, 59 (19), 10604– 10614, DOI: 10.1021/jf20315493https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXhtFKnt7rM&md5=2674734ad70922c56ab1741ecc6e5aadCharacterization of Lignin Structures and Lignin-Carbohydrate Complex (LCC) Linkages by Quantitative 13C and 2D HSQC NMR SpectroscopyYuan, Tong-Qi; Sun, Shao-Ni; Xu, Feng; Sun, Run-CangJournal of Agricultural and Food Chemistry (2011), 59 (19), 10604-10614CODEN: JAFCAU; ISSN:0021-8561. (American Chemical Society)To characterize the lignin structures and lignin-carbohydrate complex (LCC) linkages, milled wood lignin (MWL) and mild acidolysis lignin (MAL) with a high content of assocd. carbohydrates were sequentially isolated from ball-milled poplar wood. Quantification of their structural features has been achieved by using a combination of quant. 13C and 2D HSQC NMR techniques. The results showed that acetylated 4-O-methylgluconoxylan is the main carbohydrate assocd. with lignins, and acetyl groups frequently acylate the C2 and C3 positions. MWL and MAL exhibited similar structural features. The main substructures were β-O-4' aryl ether, resinol, and phenylcoumaran, and their abundances per 100 Ar units changed from 41.5 to 43.3, from 14.6 to 12.7, and from 3.7 to 4.0, resp. The S/G ratios were estd. to be 1.57 and 1.62 for MWL and MAL, resp. Ph glycoside and benzyl ether LCC linkages were clearly quantified, whereas the amt. of γ-ester LCC linkages was ambiguous for quantification.
- 4Gierer, J. Chemical Aspects of Kraft Pulping. Wood Sci. Technol. 1980, 14 (4), 241– 266, DOI: 10.1007/BF003834534https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaL3MXmslCnsQ%253D%253D&md5=e05b14fbda370a2fe83da74433159218Chemical aspects of kraft pulpingGierer, J.Wood Science and Technology (1980), 14 (4), 241-66CODEN: WOSTBE; ISSN:0043-7719.In kraft pulping of wood chips, degrdn. and condensation reactions of lignin, the formation of quinone methide intermediates, the course of delignification, and degrdn. of carbohydrates are reviewed with 75 refs.
- 5Gosselink, R. J. A. Lignin as a Renewable Aromatic Resource for the Chemical Industry . Ph.D. Thesis, Wageningen University, Wageningen, Netherlands, 2011.There is no corresponding record for this reference.
- 6Chakar, F. S.; Ragauskas, A. J. Review of Current and Future Softwood Kraft Lignin Process Chemistry. Ind. Crops Prod. 2004, 20 (2), 131– 141, DOI: 10.1016/j.indcrop.2004.04.0166https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2cXotFCntb0%253D&md5=cf61bb642b156646310842fa001f465bReview of current and future softwood kraft lignin process chemistryChakar, Fadi S.; Ragauskas, Arthur J.Industrial Crops and Products (2004), 20 (2), 131-141CODEN: ICRDEW; ISSN:0926-6690. (Elsevier B.V.)A review. The structure of lignin has remained one of the most difficult biopolymers to characterize, however recent advances in anal. chem. and spectroscopy have dramatically improved our knowledge of this natural resource. This paper highlights our current understanding of lignin structure and examines the process chem. surrounding kraft pulping. The application of this knowledge, with respect to converting lignin into novel biomaterials, biocomposites, and biofuels is examd. briefly.
- 7Henriksson, G.; Li, J.; Zhang, L.; Lindström, M. Lignin Utilization. In Thermochemical Conversion of Biomass to Liquid Fuels and Chemicals; Crocker, M., Ed.; RSC Energy and Environment Series; Royal Society of Chemistry: London, 2010.There is no corresponding record for this reference.
- 8Lora, J. H. Lignin: A Platform for Renewable Aromatic Polymeric Materials. Quality Living Through Chemurgy and Green Chemistry; Springer: Berlin, Heidleberg, Germany, 2016; pp 221– 261.There is no corresponding record for this reference.
- 9Biermann, C. J. Handbook of Pulping and Papermaking; Academic Press: Cambridge, MA, 1996.There is no corresponding record for this reference.
- 10Chapple, C.; Ladisch, M.; Meilan, R. Loosening Lignin’s Grip on Biofuel Production. Nat. Biotechnol. 2007, 25 (7), 746– 748, DOI: 10.1038/nbt0707-74610https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2sXnsFartbw%253D&md5=688db6d460b0c70686522c899d66576fLoosening lignin's grip on biofuel productionChapple, Clint; Ladisch, Michael; Meilan, RickNature Biotechnology (2007), 25 (7), 746-748CODEN: NABIF9; ISSN:1087-0156. (Nature Publishing Group)There is no expanded citation for this reference.
- 11Raud, M.; Tutt, M.; Olt, J.; Kikas, T. Dependence of the Hydrolysis Efficiency on the Lignin Content in Lignocellulosic Material. Int. J. Hydrogen Energy 2016, 41 (37), 16338– 16343, DOI: 10.1016/j.ijhydene.2016.03.19011https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC28XmtVOns70%253D&md5=6bc5c56da2fdda2a254e291abb84630cDependence of the hydrolysis efficiency on the lignin content in lignocellulosic materialRaud, M.; Tutt, M.; Olt, J.; Kikas, T.International Journal of Hydrogen Energy (2016), 41 (37), 16338-16343CODEN: IJHEDX; ISSN:0360-3199. (Elsevier Ltd.)Lignocellulosic material is the most promising feedstock for bioethanol prodn.; however, due to the varying physicochem. characteristics of different biomasses, it is necessary to select a biomass suitable for bioethanol prodn. For this purpose, several different alternative non-food energy crops were chosen to investigate their suitability for bioethanol prodn., considering their cellulose, hemicellulose and lignin content. The traditional three-step bioethanol prodn. process was used, where dil. acid was applied for biomass pre-treatment. Glucose and ethanol yields and hydrolysis efficiency were used to evaluate the suitability of different energy crops for bioethanol prodn. The results show that the glucose yield increases as the cellulose content in the biomass rises. However, a sharp decrease in hydrolysis efficiency was noted in the lignin content range of 7-9 g 100 g-1. The lower hydrolysis efficiency also resulted in a lower ethanol yield in the next step of the bioethanol prodn. process.
- 12Ragauskas, A. J.; Beckham, G. T.; Biddy, M. J.; Chandra, R.; Chen, F.; Davis, M. F.; Davison, B. H.; Dixon, R. A.; Gilna, P.; Keller, M. Lignin Valorization: Improving Lignin Processing in the Biorefinery. Science 2014, 344, 6185, DOI: 10.1126/science.1246843There is no corresponding record for this reference.
- 13Fache, M.; Boutevin, B.; Caillol, S. Vanillin Production from Lignin and Its Use as a Renewable Chemical. ACS Sustainable Chem. Eng. 2016, 4 (1), 35– 46, DOI: 10.1021/acssuschemeng.5b0134413https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXhvF2itr7E&md5=3c96f266ab9350361267bfaea10790b1Vanillin Production from Lignin and Its Use as a Renewable ChemicalFache, Maxence; Boutevin, Bernard; Caillol, SylvainACS Sustainable Chemistry & Engineering (2016), 4 (1), 35-46CODEN: ASCECG; ISSN:2168-0485. (American Chemical Society)A review. The use of vanillin as a building block for the chem. industry is discussed in this article. Vanillin is currently one of the only mol. phenolic compds. manufd. on an industrial scale from biomass. It has thus the potential to become a key-intermediate for the synthesis of bio-based polymers, for which arom. monomers are needed to reach good thermo-mech. properties. After a first part dedicated to the current sousing of vanillin, this article focuses on the alk. oxidn. lignin-to-vanillin process, reporting advantages and limits, discusses the various post-depolymn. methods for product isolation and finally examines the outlook for the wider use of vanillin as a key building block for the chem. industry.
- 14Culebras, M.; Sanchis, M. J.; Beaucamp, A.; Carsí, M.; Kandola, B. K.; Horrocks, A. R.; Panzetti, G.; Birkinshaw, C.; Collins, M. N. Understanding the Thermal and Dielectric Response of Organosolv and Modified Kraft Lignin as a Carbon Fibre Precursor. Green Chem. 2018, 20 (19), 4461– 4472, DOI: 10.1039/C8GC01577E14https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1cXhtlajsbrI&md5=f5f8e66e7cc1de8b4190bec0844c5e89Understanding the thermal and dielectric response of organosolv and modified kraft lignin as a carbon fibre precursorCulebras, Mario; Sanchis, Maria J.; Beaucamp, Anne; Carsi, Marta; Kandola, Baljinder K.; Horrocks, A. Richard; Panzetti, Gianmarco; Birkinshaw, Colin; Collins, Maurice N.Green Chemistry (2018), 20 (19), 4461-4472CODEN: GRCHFJ; ISSN:1463-9262. (Royal Society of Chemistry)Understanding the thermal behavior of lignin is crucial to realize its valorization as an engineering polymer. Two hardwood lignins, organosolv (OSL) and chem. modified kraft lignin (ML) were chosen to represent important classes of renewable and abundant raw materials. The relation between ionic mobility and viscosity in OSL and ML was studied. The rheol. results were interpreted in terms of the competitive processes of thermal plasticization and stiffening through crosslinking. Results show that with OSL, crosslinking proceeds relatively rapidly, and this is consistent with its more reactive structure. Higher mol. wt. (Mw) influenced the melt stability as crosslinking kinetics was reduced and this was attributed to the redn. of chain ends available for crosslinking reactions. Scanning calorimetry has shown that both materials are glassy and pass through the glass transition between 100 °C and 115 °C, with the higher mol. wt. modified material having a slightly higher Tg. Both lignins show pronounced maxima in the Gram-Schmidt plots for methane or methanol around 400 °C. However, a significant difference between the materials is obsd. with the detection of a strong carbonyl peak in the evolution products of the ML, which is attributed to the scission of the hydroxypropyl substituent present in the ML structure. The differences in the degrdn. processes are further reflected in the dielec. properties of the partially degraded materials where loss maxima occur at different temps. and show different degrees of frequency dependence. An important observation is the difference in cond., where higher values for OSL are attributed to the crosslinking between adjacent benzene rings, whereas with the ML, a lower cond. is assocd. with intrinsically less conductive intermol. linkages. These results demonstrate that the thermal decompn. of the two lignins follows significantly different paths at the mol. level. With the more reactive OSL, it appears to be the case that there is a greater tendency to form direct ring to ring crosslinks and this is significant for the properties of the intended end product.
- 15Jiang, W.; Liu, S.; Wu, C.; Liu, Y.; Yang, G.; Ni, Y. Super-Stable, Solvent-Resistant and Uniform Lignin Nanorods and Nanospheres with a High Yield in a Mild and Facile Process. Green Chem. 2020, 22 (24), 8734– 8744, DOI: 10.1039/D0GC02887H15https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXitlKktLbF&md5=78b9e7be09cfc218ffe5119de547d2f9Super-stable, solvent-resistant and uniform lignin nanorods and nanospheres with a high yield in a mild and facile processJiang, Weikun; Liu, Shuyun; Wu, Chaojun; Liu, Yu; Yang, Guihua; Ni, YonghaoGreen Chemistry (2020), 22 (24), 8734-8744CODEN: GRCHFJ; ISSN:1463-9262. (Royal Society of Chemistry)Lignin-based nanomaterials have attracted much attention in value-added functional material fields due to their green/sustainable nature; however, it is a challenge to control the morphol. of lignin nanoparticles, and furthermore, to make them stable in org. solvent systems. Herein, for the first time we developed a green and simple approach for producing lignin nanorods, in addn. to lignin nanospheres, both of which are stable in various org. solvents. The prepn. process involves two steps: (1) lignosulfonate (LS) is fractionated into three fractions, namely, LS90, LS70, and LS40 using 90% ethanol, 70% ethanol and 40% ethanol sequentially; (2) lignin nanorods are obtained from the LS40 fraction, while lignin nanospheres are obtained from LS70 by an anti-solvent method. During the lignin self-assembly process, for the LS40 fraction, the lignin structures are in a flat oblate ellipsoid conformation, and the J-aggregation of their arom. structures occurs on the flat sides of the oblate ellipsoid, leading to the formation of lignin nanorods. In contrast, for the LS70 fraction, lignin aggregation occurs randomly because of its near-spherical small ellipsoid conformation in soln., leading to the formation of lignin nanospheres. The entire prepn. process of lignin nanorods and lignin nanospheres is simple, without the use of templates, complex chem. reactions and rigorous conditions. The lignin nanorods and lignin nanospheres exhibit excellent uniformity and dispersibility, and long-term stability in various org. solvents. This study not only presents a green, facile and economical approach for prepg. lignin nanorods, as well as lignin nanospheres, but also provides a promising new value-added utilization pathway for lignosulfonate.
- 16Yang, Y.; Deng, Y.; Tong, Z.; Wang, C. Renewable Lignin-Based Xerogels with Self-Cleaning Properties and Superhydrophobicity. ACS Sustainable Chem. Eng. 2014, 2 (7), 1729– 1733, DOI: 10.1021/sc500250b16https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXpt1yqsL4%253D&md5=ef9ab4c06e766627b2f36c9b00c4655eRenewable Lignin-Based Xerogels with Self-Cleaning Properties and SuperhydrophobicityYang, Yu; Deng, Yonghong; Tong, Zhen; Wang, ChaoyangACS Sustainable Chemistry & Engineering (2014), 2 (7), 1729-1733CODEN: ASCECG; ISSN:2168-0485. (American Chemical Society)A novel diisocyanate-modified lignin xerogel is facilely prepd. using renewable lignin as precursors via a sol-gel process and ambient pressure drying method. The xerogel possesses high performance in self-cleaning and superhydrophobicity with no need for further hydrophobic modification. Furthermore, the xerogel obtained can find potential applications in absorbents, coatings, and scaffolds.
- 17Kai, D.; Zhang, K.; Jiang, L.; Wong, H. Z.; Li, Z.; Zhang, Z.; Loh, X. J. Sustainable and Antioxidant Lignin–Polyester Copolymers and Nanofibers for Potential Healthcare Applications. ACS Sustainable Chem. Eng. 2017, 5 (7), 6016– 6025, DOI: 10.1021/acssuschemeng.7b0085017https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXosVOqurw%253D&md5=4786bdc2c3d5e3ee4d729ba82bd87589Sustainable and Antioxidant Lignin-Polyester Copolymers and Nanofibers for Potential Healthcare ApplicationsKai, Dan; Zhang, Kangyi; Jiang, Lu; Wong, Hua Zhong; Li, Zibiao; Zhang, Zheng; Loh, Xian JunACS Sustainable Chemistry & Engineering (2017), 5 (7), 6016-6025CODEN: ASCECG; ISSN:2168-0485. (American Chemical Society)Lignin polymn. has been considered as an effective approach for lignin valorization. Herein we report the synthesis of a series of new lignin-based copolymers (lignin-poly(ε-caprolactone-co-lactide), lignin-PCLLA) via solvent-free ring-opening polymn. Lignin-PCLLA copolymers with tunable mol. wts. (10 to 16 kDa) and glass transition temps. (-40 to 40 °C) were obtained. Such copolymers were engineered into ultrafine nanofibers by blending with polyesters (polycaprolactone, PCL and poly(L-lactic acid), PLLA) via electrospinning. Both PCL/lignin-PCLLA and PLLA/lignin-PCLLA nanofibers displayed uniform and beadless nanofibrous morphol. The size (diams. ranging from 300 to 500 nm) and tensile tests of the obtained nanofibers indicated that the lignin copolymers are miscible with the polyester matrixes and can significantly improve the mech. properties of the nanofibers. Moreover, good antioxidant activity and biocompatibility of the lignin nanofibers were demonstrated in vitro, certifying the great potential of lignin-PCLLA copolymers and nanofibers for biomedical or healthcare applications.
- 18Wei, C.; Zhu, X.; Peng, H.; Chen, J.; Zhang, F.; Zhao, Q. Facile Preparation of Lignin-Based Underwater Adhesives with Improved Performances. ACS Sustainable Chem. Eng. 2019, 7 (4), 4508– 4514, DOI: 10.1021/acssuschemeng.8b0673118https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXitlKmsLg%253D&md5=f501a53bfd62f44d0858ed0469ebefc9Facile Preparation of Lignin-Based Underwater Adhesives with Improved PerformancesWei, Congying; Zhu, Xiangwei; Peng, Haiyan; Chen, Jianjun; Zhang, Fang; Zhao, QiangACS Sustainable Chemistry & Engineering (2019), 7 (4), 4508-4514CODEN: ASCECG; ISSN:2168-0485. (American Chemical Society)Bioinspired wet adhesives have demonstrated versatile applicability in humid conditions, but the attainment of catecholic protein mimics comprises multistep synthesis and use of complex chem. components. Advanced wet adhesives derived from inexpensive bioresources and green processing are highly expected. We report a straightforward means to underwater-implemented adhesives from aq. mixing of lignosulfonate (LS) and a polyamidoamine-epichlorohydrin (PAE-Cl) soln. The formation of a fluidic LS-PAE complex was driven by a delicate balance between electrostatic attraction and hydrophilic stabilization. The obtained adhesive highlights instant wet adhesion on diverse submerged surfaces and spontaneous curing in water. More importantly, it demonstrates robust and stable bonding strength over the alkali, salty, high-temp., and long-time soaking conditions. This work advanced the development of lignin into functional wet adhesives through a green and sustainable approach.
- 19Baker, D. A.; Rials, T. G. Recent Advances in Low-Cost Carbon Fiber Manufacture from Lignin. J. Appl. Polym. Sci. 2013, 130 (2), 713– 728, DOI: 10.1002/app.3927319https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXms1OisLg%253D&md5=a04827db94b77c03041c9732f0f591c7Recent advances in low-cost carbon fiber manufacture from ligninBaker, Darren A.; Rials, Timothy G.Journal of Applied Polymer Science (2013), 130 (2), 713-728CODEN: JAPNAB; ISSN:0021-8995. (John Wiley & Sons, Inc.)A review. The confluence of two US energy policy mandates, the 2012 Corporate Av. Fuel Economy Stds. and Renewable Fuels Std. #2, provide the opportunity to examine the possibility of high-value materials from lignin with increased depth. In this case, the desire to provide lighter, low-cost materials for automobiles to reduce fuel consumption, and to improve the economics of biorefineries for fuel prodn., have led to an increased interest in low-cost carbon fiber manuf. from lignin. For this review the authors provide the context of subject matter importance, a cost comparison of potential low-cost carbon fibers, a brief review of historical work, a review of more recent work, and a limited tech. discussion followed by recommendations for future directions. As the available material for review is limited, the author includes many refs. to publicly available government documents and reviewed proceedings that are generally difficult to locate. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 000: 000-000, 2013.
- 20Geng, S.; Wei, J.; Jonasson, S.; Hedlund, J.; Oksman, K. Multifunctional Carbon Aerogels with Hierarchical Anisotropic Structure Derived from Lignin and Cellulose Nanofibers for CO2 Capture and Energy Storage. ACS Appl. Mater. Interfaces 2020, 12 (6), 7432– 7441, DOI: 10.1021/acsami.9b1995520https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXhtlWhurk%253D&md5=a1615e53c2f26c21293e7c17482f2beeMultifunctional Carbon Aerogels with Hierarchical Anisotropic Structure Derived from Lignin and Cellulose Nanofibers for CO2 Capture and Energy StorageGeng, Shiyu; Wei, Jiayuan; Jonasson, Simon; Hedlund, Jonas; Oksman, KristiinaACS Applied Materials & Interfaces (2020), 12 (6), 7432-7441CODEN: AAMICK; ISSN:1944-8244. (American Chemical Society)In current times, CO2 capture and lightwt. energy storage are receiving significant attention and will be vital functions in next-generation materials. Porous carbonaceous materials have great potential in these areas, whereas most of the developed carbon materials still have significant limitations, such as nonrenewable resources, complex and costly processing, or the absence of tailorable structure. In this study, a new strategy is developed for using the currently underutilized lignin and cellulose nanofibers, which can be extd. from renewable resources to produce high-performance multifunctional carbon aerogels with a tailorable, anisotropic pore structure. Both the macro- and microstructure of the carbon aerogels can be simultaneously controlled by carefully tuning the wt. ratio of lignin to cellulose nanofibers in the precursors, which considerably influences their final porosity and surface area. The designed carbon aerogels demonstrate excellent performance in both CO2 capture and capacitive energy storage, and the best results exhibit a CO2 adsorption capacity of 5.23 mmol g-1 at 273 K and 100 kPa and a specific elec. double-layer capacitance of 124 F g-1 at a c.d. of 0.2 A g-1, indicating that they have great future potential in the relevant applications.
- 21Guo, N.; Li, M.; Sun, X.; Wang, F.; Yang, R. Enzymatic Hydrolysis Lignin Derived Hierarchical Porous Carbon for Supercapacitors in Ionic Liquids with High Power and Energy Densities. Green Chem. 2017, 19 (11), 2595– 2602, DOI: 10.1039/C7GC00506G21https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXlvFyksLY%253D&md5=757b7deacc069b7b71ed16c0c5eb792dEnzymatic hydrolysis lignin derived hierarchical porous carbon for supercapacitors in ionic liquids with high power and energy densitiesGuo, Nannan; Li, Min; Sun, Xingkai; Wang, Feng; Yang, RuGreen Chemistry (2017), 19 (11), 2595-2602CODEN: GRCHFJ; ISSN:1463-9262. (Royal Society of Chemistry)Porous carbons were obtained by chem. activation of hydrochar, prepd. by hydrothermal carbonization using enzymic hydrolysis lignin originated from the butanol fermn. of corn straw. The intermediate hydrochar was activated using different KOH/hydrochar wt. ratios to evaluate the effect of these ratios on its electrochem. properties. The materials thus prepd. exhibited high sp. surface areas in the range 1290-1660 m2 g-1 mainly attributed to the three-dimensional hierarchical texture made up of abundant micropores, small mesopores and macropores, and high elec. cond. in the 4.0-5.4 S cm-1 range. Consequently, the samples show high specific capacitance, superior rate performance and outstanding durability in three-electrode and two-electrode systems in 6 M KOH. The as-assembled sym. supercapacitor in an ionic liq. electrolyte system exhibits a superior energy d. of 46.8 W h kg-1 and a value of 22.9 W h kg-1 is maintained even at an ultrahigh power d. of 25 400 W kg-1. These materials possessing excellent structural features are an ideal candidate for high performance supercapacitors.
- 22Herou, S.; Ribadeneyra, M. C.; Madhu, R.; Araullo-Peters, V.; Jensen, A.; Schlee, P.; Titirici, M. Ordered Mesoporous Carbons from Lignin: A New Class of Biobased Electrodes for Supercapacitors. Green Chem. 2019, 21 (3), 550– 559, DOI: 10.1039/C8GC03497D22https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXkvFSgtg%253D%253D&md5=931b2d91fc1d551b8c16e12a37de0740Ordered mesoporous carbons from lignin: a new class of biobased electrodes for supercapacitorsHerou, Servann; Ribadeneyra, Maria Crespo; Madhu, Rajesh; Araullo-Peters, Vicente; Jensen, Anders; Schlee, Philipp; Titirici, MagdalenaGreen Chemistry (2019), 21 (3), 550-559CODEN: GRCHFJ; ISSN:1463-9262. (Royal Society of Chemistry)We report the synthesis of sustainable ordered mesoporous carbons (OMCs) produced from lignin, using the evapn. induced self-assembly (EISA) method. We demonstrated that it is possible to replace half of the phloroglucinol (a well-known carbon precursor currently not derived from bioprecursors) by hardwood organosolv lignin while obtaining a highly ordered pore structure. Notably, we also used glyoxal instead of formaldehyde as a crosslinker, which makes the synthesis route even "greener" with respect to the toxicity of the precursors and their renewable sourcing. Finally, we demonstrated that the resulting carbons make powerful electrodes in supercapacitors and we have made clear correlations between the porous structure and their electrochem. performance in sym. supercapacitors in order to deliver tailored energy storage to meet various demands (i.e. amt. of charge stored vs. power of delivery).
- 23Baker, D. A.; Gallego, N. C.; Baker, F. S. On the Characterization and Spinning of an Organic-Purified Lignin toward the Manufacture of Low-Cost Carbon Fiber. J. Appl. Polym. Sci. 2012, 124 (1), 227– 234, DOI: 10.1002/app.3359623https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXht1OhsbnE&md5=599787e266c544d07985f495c13b28b4On characterization and spinning of organic-purified lignin toward manufacture of low-cost carbon fiberBaker, Darren A.; Gallego, Nidia C.; Baker, Frederick S.Journal of Applied Polymer Science (2012), 124 (1), 227-234CODEN: JAPNAB; ISSN:0021-8995. (John Wiley & Sons, Inc.)A Kraft hardwood lignin (HWL) and an org.-purified hardwood lignin (HWL-OP) were evaluated as potential precursors for the prodn. of low-cost carbon fibers. It was found that the unpurified HWL exhibited poor spinnability while the HWL-OP exhibited excellent spinnability characteristics. Fibers of various diams. were obtained from the HWL-OP. Thermostabilization studies showed that oxidative stabilization can only be used to convert HWL-OP-based fibers into carbon fibers if extremely low heating rates are applied. Carbonized lignin-based fibers had tensile strength of 0.51 GPa and tensile modulus of 28.6 GPa.
- 24Qu, W.; Liu, J.; Xue, Y.; Wang, X.; Bai, X. Potential of Producing Carbon Fiber from Biorefinery Corn Stover Lignin with High Ash Content. J. Appl. Polym. Sci. 2018, 135 (4), 45736, DOI: 10.1002/app.45736There is no corresponding record for this reference.
1–11.
- 25Sudo, K.; Shimizu, K. A New Carbon Fiber from Lignin. J. Appl. Polym. Sci. 1992, 44 (1), 127– 134, DOI: 10.1002/app.1992.07044011325https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK38XmsFCgsQ%253D%253D&md5=323428917b7cb0b3c1fa3b504e02d188A new carbon fiber from ligninSudo, K.; Shimizu, K.Journal of Applied Polymer Science (1992), 44 (1), 127-34CODEN: JAPNAB; ISSN:0021-8995.A new C fiber was prepd. from the lignin (steam-exploded lignin), which was isolated from steam-exploded birch wood (Betula platyphylla). The lignin was modified to melt thermally on hydrogenolysis. The chloroform sol. and CS2 insol. fraction (HL) of the reaction products was heated at 300-350° for 30 min, giving a molten viscous material (HHL). The HHL had a softening point of 110° and melted at >145° to form viscous liq. When HHL was subjected to a spinning test, according to a conventional fusion spinning method at a speed >100 m/min, a fine filament could be continuously formed through a pinhole (diam. 0.3 mm). After the filaments were heated in air at 1-2°/min for ≤210°, by which time the filament was converted to have an infusible property, the filaments were carbonized by heating from room temp. to 1000° at a heating rate of 5°/min in a stream of N. The typical properties of the lignin-based C fiber were: fiber diam. 7.6 ±2.7 μm, elongation 1.63 ±0.29%, tensile strength 660 ±230 MPa, modulus of elasticity 40.7 ±6.3 GPa. The chem. structure of the precursor was remarkably changed from that of the original lignin, indicating the elimination of aliph. functional groups implied originally in the starting material.
- 26Uraki, Y.; Kubo, S.; Kurakami, H.; Sano, Y. Activated Carbon Fibers from Acetic Acid Lignin. Holzforschung 1997, 51 (2), 188– 192, DOI: 10.1515/hfsg.1997.51.2.18826https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK2sXltFOqu74%253D&md5=39ac2e32e64ca54f58f273ca16e47eebActivated carbon fibers from acetic acid ligninUraki, Yasumitsu; Kubo, Satoshi; Kurakami, Harutora; Sano, YoshihiroHolzforschung (1997), 51 (2), 188-192CODEN: HOLZAZ; ISSN:0018-3830. (de Gruyter)Activated carbon fibers (ACF's) were prepd. from acetic acid lignin-based carbon fibers by steam activation. The ACF had excellent properties, such as more rapid adsorption rate and higher iodine and methylene blue adsorption capacities, as compared to a com. available activated carbon. The adsorption mechanism of ACF was quite different from that of activated carbon (AC), as supported by the micropore distribution profiles.
- 27Kadla, J.; Kubo, S.; Venditti, R.; Gilbert, R.; Compere, A.; Griffith, W. Lignin-Based Carbon Fibers for Composite Fiber Applications. Carbon 2002, 40 (15), 2913– 2920, DOI: 10.1016/S0008-6223(02)00248-827https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD38Xot1WmtrY%253D&md5=9be05ea6b16322abcc57eebd45ea66eaLignin-based carbon fibers for composite fiber applicationsKadla, J. F.; Kubo, S.; Venditti, R. A.; Gilbert, R. D.; Compere, A. L.; Griffith, W.Carbon (2002), 40 (15), 2913-2920CODEN: CRBNAH; ISSN:0008-6223. (Elsevier Science Ltd.)Carbon fibers were produced for the first time from a com. available kraft lignin, without any chem. modification, by thermal spinning followed by carbonization. A fusible lignin with excellent spinnability to form a fine filament was produced with a thermal pretreatment under vacuum. Blending the lignin with poly(ethylene oxide) (PEO) further facilitated fiber spinning, but at PEO levels >5%, the blends could not be stabilized without the individual fibers fusing together. The carbon fibers produced had an over all yield of 45%. The tensile strength and modulus increased with decreasing fiber diam., and are comparable to those of much smaller diam. carbon fibers produced from phenolated exploded lignins. In view of the mech. properties, tensile strength 400-550 MPa and elastic modulus 30-60 GPa, kraft lignin should be further investigated as a precursor for general grade carbon fibers.
- 28Pandolfo, T.; Ruiz, V.; Seepalakottai, S.; Nerkar, J. Ch 2. General Properties of Electrochemical Capacitors. In Supercapacitors: Materials, Systems, and Applications; Lu, M., Ed.; Wiley-VCH Verlag GmbH & Co.: Weinheim, Germany, 2013; pp 69– 110.There is no corresponding record for this reference.
- 29Wei, J.; Geng, S.; Pitkänen, O.; Jarvinen, T.; Kordas, K.; Oksman, K. Green Carbon Nanofiber Networks for Advanced Energy Storage. ACS Applied Energy Materials 2020, 3 (4), 3530– 3540, DOI: 10.1021/acsaem.0c0006529https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXmt1eqtbo%253D&md5=b5c96368b128d74909e7a80368646f1bGreen Carbon Nanofiber Networks for Advanced Energy StorageWei, Jiayuan; Geng, Shiyu; Pitkaenen, Olli; Jaervinen, Topias; Kordas, Krisztian; Oksman, KristiinaACS Applied Energy Materials (2020), 3 (4), 3530-3540CODEN: AAEMCQ; ISSN:2574-0962. (American Chemical Society)Energy storage devices such as supercapacitors of high performance are in great need due to the continuous expansion of digitalization and related devices for mobile electronics, autonomous sensors, and vehicles of different kinds. However, the nonrenewable resources and often complex prepn. processes assocd. with electrode materials and structures pose limited scale-up in prodn. and difficulties in versatile utilization of the devices. Here, free-standing and flexible carbon nanofiber networks derived from renewable and abundant bioresources are demonstrated. By a simple optimization of carbonization, the carbon nanofiber networks reach a large surface area of 1670 m2 g-1 and excellent specific gravimetric capacitance of ~ 240 F g-1, outperforming many other nanostructured carbon, activated carbon, and even those decorated with metal oxides. The remarkable electrochem. performance and flexibility of the green carbon networks enable an all-solid-state supercapacitor device, which displays a device capacitance of 60.4 F g-1 with a corresponding gravimetric energy d. of 8.4 Wh kg-1 while maintaining good mech. properties.
- 30Lai, C.; Zhou, Z.; Zhang, L.; Wang, X.; Zhou, Q.; Zhao, Y.; Wang, Y.; Wu, X.-F.; Zhu, Z.; Fong, H. Free-Standing and Mechanically Flexible Mats Consisting of Electrospun Carbon Nanofibers Made from a Natural Product of Alkali Lignin as Binder-Free Electrodes for High-Performance Supercapacitors. J. Power Sources 2014, 247, 134– 141, DOI: 10.1016/j.jpowsour.2013.08.08230https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhs12lu7%252FE&md5=5424be2b998f439d74ededbb8eba9c16Free-standing and mechanically flexible mats consisting of electrospun carbon nanofibers made from a natural product of alkali lignin as binder-free electrodes for high-performance supercapacitorsLai, Chuilin; Zhou, Zhengping; Zhang, Lifeng; Wang, Xiaoxu; Zhou, Qixin; Zhao, Yong; Wang, Yechun; Wu, Xiang-Fa; Zhu, Zhengtao; Fong, HaoJournal of Power Sources (2014), 247 (), 134-141CODEN: JPSODZ; ISSN:0378-7753. (Elsevier B.V.)Mech. flexible mats consisting of electrospun carbon nanofibers (ECNFs) were prepd. by first electrospinning aq. mixts. contg. a natural product of alkali lignin together with polyvinyl alc. (PVA) into composite nanofiber mats followed by stabilization in air and carbonization in an inert environment. Morphol. and structural properties, as well as sp. surface area, total pore vol., av. pore size, and pore size distribution, of the lignin-based ECNF mats were characterized; and their electrochem. performances (i.e., capacitive behaviors) were evaluated by cyclic voltammetry, galvanostatic charge/discharge, and electrochem. impedance spectroscopy. The lignin-based ECNF mats exhibited outstanding performance as free-standing and/or binder-free electrodes of supercapacitors. For example, the ECNFs made from the composite nanofibers with mass ratio of lignin/PVA being 70/30 (i.e., ECNFs (70/30)) had the av. diam. of ∼100 nm and the Brunauer-Emmett-Teller (BET) sp. surface area of ∼583 m2.g-1. The gravimetric capacitance of ECNFs (70/30) electrode in 6 M KOH aq. electrolyte exhibited 64 F.g-1 at c.d. of 400 mA.g-1 and 50 F.g-1 at 2000 mA.g-1. The ECNFs (70/30) electrode also exhibited excellent cycling durability/stability, and the gravimetric capacitance merely reduced by ∼10% after 6000 cycles of charge/discharge.
- 31Hu, S.; Zhang, S.; Pan, N.; Hsieh, Y.-L. High Energy Density Supercapacitors from Lignin Derived Submicron Activated Carbon Fibers in Aqueous Electrolytes. J. Power Sources 2014, 270, 106– 112, DOI: 10.1016/j.jpowsour.2014.07.06331https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXht1KgsLfL&md5=26e8a6a19d623c5933a9acc93557651bHigh energy density supercapacitors from lignin derived submicron activated carbon fibers in aqueous electrolytesHu, Sixiao; Zhang, Sanliang; Pan, Ning; Hsieh, You-LoJournal of Power Sources (2014), 270 (), 106-112CODEN: JPSODZ; ISSN:0378-7753. (Elsevier B.V.)Highly porous submicron activated carbon fibers (ACFs) were robustly generated from low sulfonated alkali lignin and fabricated into supercapacitors for capacitive energy storage. The hydrophilic and high sp. surface ACFs exhibited large-size nanographites and good elec. cond. to demonstrate outstanding electrochem. performance. ACFs from KOH activation, in particular, showed very high 344 F g-1 specific capacitance at low 1.8 mg cm-2 mass loading and 10 mV s-1 scan rate in aq. electrolytes. Even at relatively high scan rate of 50 mV s-1 and mass loading of 10 mg cm-2, a decent specific capacitance of 196 F g-1 and a remarkable areal capacitance of 0.55 F cm-2 was obtained, leading to high energy d. of 8.1 Wh kg-1 based on averaged electrodes mass. Furthermore, over 96% capacitance retention rates were achieved after 5000 charge/discharge cycles. Such excellent performance demonstrated great potential of lignin derived carbons for elec. energy storage.
- 32You, X.; Koda, K.; Yamada, T.; Uraki, Y. Preparation of Electrode for Electric Double Layer Capacitor from Electrospun Lignin Fibers. Holzforschung 2015, 69 (9), 1097– 1106, DOI: 10.1515/hf-2014-026232https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXhslCqsb%252FO&md5=c415b63cff485dd966bf7819ff59ff29Preparation of electrode for electric double layer capacitor from electrospun lignin fibersYou, Xiangyu; Koda, Keiichi; Yamada, Tatsuhiko; Uraki, YasumitsuHolzforschung (2015), 69 (9), 1097-1106CODEN: HOLZAZ; ISSN:0018-3830. (Walter de Gruyter GmbH)Lignin-based activated carbon fibers (ACFs) were prepd. by electrospinning of hardwood acetic acid lignin (HW-AAL) soln. followed by thermostabilization, carbonization, and steam activation. The thermostabilization process was able to be remarkably shortened from 38 h to 3 h with hexamethylenetetramine (hexamine) in binary solvents, AcOH/CCl4 (8/2), when compared with conventional thermostabilization processes. The resultant ACFs possessed higher sp. surface area (2185 m2 g-1) than those from com. activated carbon and electrospun lignin fibers without hexamine. These ACFs also exhibited good elec. capacitance (133.3 F g-1 at a c.d. of 1 A g-1) as electrodes of elec. double layer capacitor (EDLC) are efficient not only due to their large surfaces area but also due to their porous structure with well-developed micropores (diam.: 0.5-1.3 nm). High energy d. and power d. of this EDLC (42 Wh kg-1 and 91 kW kg-1, resp.) were also achieved.
- 33Ma, X.; Kolla, P.; Zhao, Y.; Smirnova, A. L.; Fong, H. Electrospun Lignin-Derived Carbon Nanofiber Mats Surface-Decorated with MnO2 Nanowhiskers as Binder-Free Supercapacitor Electrodes with High Performance. J. Power Sources 2016, 325, 541– 548, DOI: 10.1016/j.jpowsour.2016.06.07333https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC28XhtVGiu73N&md5=3ec17f52f1a2e1425284d6ec843b0c00Electrospun lignin-derived carbon nanofiber mats surface-decorated with MnO2 nanowhiskers as binder-free supercapacitor electrodes with high performanceMa, Xiaojing; Kolla, Praveen; Zhao, Yong; Smirnova, Alevtina L.; Fong, HaoJournal of Power Sources (2016), 325 (), 541-548CODEN: JPSODZ; ISSN:0378-7753. (Elsevier B.V.)The aim of this study is to explore innovative materials for the development of next-generation supercapacitor electrodes. The hypothesis is that, upon the surface-decoration with appropriate amt. of MnO2 nanowhiskers, freestanding and highly graphitic electrospun carbon nanofiber (ECNF) mats (with fiber diams. of ∼200 nm and BET sp. surface areas of ∼583 m2 g-1) derived from a natural product of lignin would be binder-free supercapacitor electrodes with high performance. To test the hypothesis, the ECNF mats have been prepd. first; thereafter, the acquired ECNF mats have been surface-decorated with varied amts. of MnO2 nanowhiskers to prep. three types of ECNF/MnO2 mats. The morphol. and structural properties of ECNF and ECNF/MnO2 mats are characterized by SEM, TEM and XRD, the wt. percentages of MnO2 nanowhiskers in three ECNF/MnO2 mats are detd. by thermal gravimetric anal.; while the electrochem. performance of each mat/electrode is evaluated by cyclic voltammetry, galvanostatic charge/discharge method, and electrochem. impedance spectroscopy. This study reveals that, all of the three ECNF/MnO2 mats/electrodes have significantly enhanced electrochem. performances compared to the ECNF mat/electrode; while the ECNF/MnO2 (1:1) mat/electrode exhibits the highest gravimetric capacitance of 83.3 F g-1, energy d. of 84.3 W h kg-1, and power d. of 5.72 kW kg-1.
- 34Hu, S.; Hsieh, Y.-L. Lignin Derived Activated Carbon Particulates as an Electric Supercapacitor: Carbonization and Activation on Porous Structures and Microstructures. RSC Adv. 2017, 7 (48), 30459– 30468, DOI: 10.1039/C7RA00103G34https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXpvVKnur4%253D&md5=0fade3b61f3f681e98bffbf2d609caafLignin derived activated carbon particulates as an electric supercapacitor: carbonization and activation on porous structures and microstructuresHu, Sixiao; Hsieh, You-LoRSC Advances (2017), 7 (48), 30459-30468CODEN: RSCACL; ISSN:2046-2069. (Royal Society of Chemistry)Microporous and mesoporous particulate activated carbons (PACs) with unique hierarchical microstructures were facilely synthesized from alkali lignin via simultaneous carbonization and alkali hydroxide activation. Both NaOH and KOH activated PACs contained slit-like micropores and carbon microstructures with circular nanoplates of graphite-like basal planes and amorphous carbon clusters. The micropores broadened with increasing temps., holding time and alk. hydroxides. The basal planes sizes and order were enhanced with increasing temps. and holding time but lowering impregnation ratios, while amorphous carbon showed no particular patterns due to its much higher reactivity toward alkali hydroxides. The PACs with the highest micropore surface area and pore vol. (1100 m2 g-1, 0.43 cm3 g-1) were obtained at 900°C, 30 min and an impregnation ratio of 1 and fabricated into elec. supercapacitors to exhibit excellent 226 F g-1 specific capacitance, 7.8 W h kg-1 energy d. and 47 kW kg-1 power d. as well as over 92% capacitance retention after 5000 cycles.
- 35Fang, W.; Yang, S.; Yuan, T.-Q.; Charlton, A.; Sun, R.-C. Effects of Various Surfactants on Alkali Lignin Electrospinning Ability and Spun Fibers. Ind. Eng. Chem. Res. 2017, 56 (34), 9551– 9559, DOI: 10.1021/acs.iecr.7b0249435https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXht12mtLnN&md5=66a019f7c44312a6936bcca94d50a3ffEffects of Various Surfactants on Alkali Lignin Electrospinning Ability and Spun FibersFang, Wei; Yang, Sen; Yuan, Tong-Qi; Charlton, Adam; Sun, Run-CangIndustrial & Engineering Chemistry Research (2017), 56 (34), 9551-9559CODEN: IECRED; ISSN:0888-5885. (American Chemical Society)Anionic, cationic, and nonionic surfactants with varying concns. (0.2-1.2%) were introduced to neutralize beads on lignin nanofibers by decreasing the surface tension of spinning dopes. The surfactants used in this work were sodium dodecyl sulfate (SDS), N,N,N-trimethyl-1-dodecanaminium bromide (DTAB), and Triton X-100 (TX-100). The effects of viscosity, rheol. properties, surface tension, and cond. of the solns. on the morphol. and physicochem. performances of fibers were investigated. As expected, the presence of certain amts. of surfactants eliminated the beads and resulted in the formation of smooth and bead-free fibers with small diams. Furthermore, the gravimetric capacitance of the carbon mat with 1% SDS was slightly improved from 66.3 to 80.7 F g-1. The results suggested that the surfactants benefit from the electrospinning of lignin and allow for the control over nanofiber morphol. without compromising their performance as supercapacitor electrodes.
- 36Shu, R.; Zhang, Q.; Ma, L.; Xu, Y.; Chen, P.; Wang, C.; Wang, T. Insight into the Solvent, Temperature and Time Effects on the Hydrogenolysis of Hydrolyzed Lignin. Bioresour. Technol. 2016, 221, 568– 575, DOI: 10.1016/j.biortech.2016.09.04336https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC28XhsFamsrbF&md5=9bae3e4108c7a91f522935b169d95a7cInsight into the solvent, temperature and time effects on the hydrogenolysis of hydrolyzed ligninShu, Riyang; Zhang, Qi; Ma, Longlong; Xu, Ying; Chen, Pengru; Wang, Chenguang; Wang, TiejunBioresource Technology (2016), 221 (), 568-575CODEN: BIRTEB; ISSN:0960-8524. (Elsevier Ltd.)The aim of this study is to explore the reaction mediums and conditions for producing high yield of valuable monomers from concd. sulfuric acid hydrolyzed lignin. The solvent, temp. and time effects on the hydrogenolysis of hydrolyzed lignin were investigated under the catalysis of Pd/C and CrCl3. Supercrit. methanol exhibits the best depolymn. performance, because of its unique diffusion, dissoln. and acid-base properties. Afterwards, the influence of reaction temp. and time on depolymn., repolymn. and coking during hydrogenolysis was examd. in methanol. The high temp. is found to favor the depolymn., with the β-O-4 linkages cleaved significantly. However, the repolymn. is promoted simultaneously, and a high amt. of β-β groups form. These reactions are in const. competition with each other and the repolymn. is preferred at excessive high temp., producing bulk char residues, that is coking. This study will provide a beneficial ref. for the maximization of lignin waste valorization.
- 37Cho, J.; Chu, S.; Dauenhauer, P. J.; Huber, G. W. Kinetics and Reaction Chemistry for Slow Pyrolysis of Enzymatic Hydrolysis Lignin and Organosolv Extracted Lignin Derived from Maplewood. Green Chem. 2012, 14 (2), 428– 439, DOI: 10.1039/C1GC16222E37https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38Xhsleksbs%253D&md5=09084ee5e9bc9c962f67599e274ec83cKinetics and reaction chemistry for slow pyrolysis of enzymatic hydrolysis lignin and organosolv extracted lignin derived from maplewoodCho, Joungmo; Chu, Sheng; Dauenhauer, Paul J.; Huber, George W.Green Chemistry (2012), 14 (2), 428-439CODEN: GRCHFJ; ISSN:1463-9262. (Royal Society of Chemistry)The kinetics and reaction chem. for the pyrolysis of Maplewood lignin were investigated using both a pyroprobe reactor and a thermogravimetric analyzer mass spectrometry (TGA-MS). Lignin residue after enzymic hydrolysis and organosolv lignin derived from Maplewood were used to measure the kinetic behaviors of lignin pyrolysis and to analyze pyrolysis product distributions. The enzymic lignin residue pyrolyzed at lower temp. than that of organosolv lignin. The differential thermogravimetric (DTG) peaks for pyrolysis of the enzymic residue were more similar to the DTG peaks for pyrolysis of the original Maplewood than DTG of the organosolv lignin. The condensable liq. volatile products were collected from a Pyroprobe reactor with a liq. nitrogen trap. The primary monomeric phenolic compds. were guaiacol, syringol, and vanillic acid. However, only 14-36 carbon% of the sample could be detected by GC-MS. Over 60 carbon% of the condensable products were heavy tar mols. that are not detectable by GC-MS. These heavy tar mols. are the primary products from pyrolysis of lignin. Intermediate solid samples were also collected at various pyrolysis temps. and characterized by elemental anal., FT-IR, DP-MAS 13C NMR, and TOC. The methoxy groups and ether linkages decreased and the non-protonated arom. carbon-carbon bonds increased in the solid residues as the pyrolysis temp. increased. The carbon content of the initial lignin feed (derived from enzymic hydrolysis) and the solid polyaroms. residue (obtained at 773 K) was 58 wt% and 74 wt% resp. This polyarom. residue contained about 69 wt% of the original lignin feed. The solid polyaroms. undergo further slow decompn. accompanied by a const. release of carbon dioxide as the pyrolysis reaction continues. The pyrolysis of the enzymic lignin residue was modelled by two reactions in series. In the first pyrolysis step the lignin was decompd. with an apparent activation energy of 74 kJ mol-1 and a heat of reaction of -8780 kJ kg-1. The second pyrolysis step had an apparent activation energy of 110 kJ mol-1 and a heat of reaction of -2819 kJ kg-1. Lignin pyrolysis has lower activation energies and higher heats of reaction than cellulose pyrolysis.
- 38Ma, R.; Xu, Y.; Zhang, X. Catalytic Oxidation of Biorefinery Lignin to Value-Added Chemicals to Support Sustainable Biofuel Production. ChemSusChem 2015, 8 (1), 24– 51, DOI: 10.1002/cssc.20140250338https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXivVWhuw%253D%253D&md5=85eb71012dd5aa0f7ceb6f6f2250f3beCatalytic Oxidation of Biorefinery Lignin to Value-added Chemicals to Support Sustainable Biofuel ProductionMa, Ruoshui; Xu, Yan; Zhang, XiaoChemSusChem (2015), 8 (1), 24-51CODEN: CHEMIZ; ISSN:1864-5631. (Wiley-VCH Verlag GmbH & Co. KGaA)A review. Transforming plant biomass to biofuel is one of the few solns. that can truly sustain mankind's long-term needs for liq. transportation fuel with minimized environmental impact. However, despite decades of effort, com. development of biomass-to-biofuel conversion processes is still not an economically viable proposition. Identifying value-added co-products along with the prodn. of biofuel provides a key soln. to overcoming this economic barrier. Lignin is the second most abundant component next to cellulose in almost all plant biomass; the emerging biomass refinery industry will inevitably generate an enormous amt. of lignin. Development of selective biorefinery lignin-to-bioproducts conversion processes will play a pivotal role in significantly improving the economic feasibility and sustainability of biofuel prodn. from renewable biomass. The urgency and importance of this endeavor has been increasingly recognized in the last few years. This paper reviews state-of-the-art oxidative lignin depolymn. chemistries employed in the papermaking process and oxidative catalysts that can be applied to biorefinery lignin to produce platform chems. including phenolic compds., dicarboxylic acids, and quinones in high selectivity and yield. The potential synergies of integrating new catalysts with com. delignification chemistries are discussed. We hope the information will build on the existing body of knowledge to provide new insights towards developing practical and com. viable lignin conversion technologies, enabling sustainable biofuel prodn. from lignocellulosic biomass to be competitive with fossil fuel.
- 39Ralph, J.; Landucci, L. L. NMR of Lignins. In Lignin and lignans: Advances in chemistry; Heitner, C., Dimmel, D., Schmidt, J., Eds.; CRC Press (Taylor & Francis Group): Boca Raton, FL, 2010; pp 137– 234.There is no corresponding record for this reference.
- 40Li, S.; Lundquist, K. A New Method for the Analysis of Phenolic Groups in Lignins by 1H NMR Spectroscopy. Nord. Pulp Pap. Res. J. 1994, 9 (3), 191– 195, DOI: 10.3183/npprj-1994-09-03-p191-19540https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK2MXhsleqtLY%253D&md5=57fd4bdaebe6ffee08d1ffb175557b5cA new method for the analysis of phenolic groups in lignins by proton NMR spectrometryLi, Shiming; Lundquist, KnutNordic Pulp & Paper Research Journal (1994), 9 (3), 191-5CODEN: NPPJEG; ISSN:0283-2631. (Arbor Publishing)Phenolic groups in lignins were analyzed by 1H NMR spectrometry at 400 and 500 MHz (DMSO-d6 soln., temp. 300 K). Under these conditions, the majority of the signals from protons in phenolic OH groups were found in the spectral range δ 8.0-9.3. Most carbonyl-conjugated phenols give signals at δ values >9.3; the corresponding types of lignin units constitute only a very small fraction of the phenolic groups. The no. of phenolic groups in milled wood lignin (MWL) from spruce was estd. as 0.24/phenylpropane unit; phenolic groups in biphenyl and diaryl ether structures constituted about 20% of the total no. of phenolic groups. Spectra of MWL from birch exhibited sep. peaks for phenols in guaiacyl units (δ ≈ 8.8) and syringyl units (δ ≈ 8.2); the total no. of phenolic groups was estd. as 0.18/phenylpropane unit. The proportion of phenols in guaiacyl units was larger than that in syringyl units.
- 41Gil, A.; Lopes, M.; Neto, C. P.; Rocha, J. Very High-Resolution 1H MAS NMR of a Natural Polymeric Material. Solid State Nucl. Magn. Reson. 1999, 15 (1), 59– 67, DOI: 10.1016/S0926-2040(99)00047-841https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD3cXivVOqtQ%253D%253D&md5=132d43600ba04e410ddd5a4b984fefaaVery high-resolution proton MAS NMR of a natural polymeric materialGil, A. M.; Lopes, M. H.; Pascoal Neto, C.; Rocha, J.Solid State Nuclear Magnetic Resonance (1999), 15 (1), 59-67CODEN: SSNRE4; ISSN:0926-2040. (Elsevier Science B.V.)The use of ultrafast magic angle spinning (> 30 kHz) in tandem with delayed echo acquisition yields very high-resoln. 1H MAS NMR spectra of complex natural org. materials. For the 1st time, very high-resoln. 1H MAS NMR spectra are reported for cork and wood components, 2 natural materials with great economic importance. The effect of the spinning rate on the 1H NMR spectra was evaluated with single-pulse acquisition and delayed-echo acquisition. The delayed-echo acquisition spectra presented line-widths as sharp as 67 and 25 Hz. The narrow peaks, characterized by proton spin-spin and spin-lattice relaxation, were assigned to the isotropic chem. shifts and the general spectral features were shown to correlate with the sample chem. structure. The tentative assignments of cork 1H MAS NMR signals were presented.
- 42Lundquist, K.; Aasen, A. J.; Daasvatn, K.; Forsgren, B.; Gustafsson, J.-A.; Hogberg, B.; Becher, J. NMR Studies of Lignins. 4. Investigation of Spruce Lignin by 1H NMR Spectroscopy. Acta Chem. Scand. 1980, 34b, 21– 26, DOI: 10.3891/acta.chem.scand.34b-0021There is no corresponding record for this reference.
- 43Chen, C.-L.; Robert, D. Characterization of Lignin by 1H and 13C NMR Spectroscopy. Methods Enzymol. 1988, 161, 137– 174, DOI: 10.1016/0076-6879(88)61017-243https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaL1MXksF2ktLk%253D&md5=63535665e4b03f3ef1e93a8f48435614Characterization of lignin by proton and carbon-13 NMR spectroscopyChen, Chen Loung; Robert, DanielleMethods in Enzymology (1988), 161 (Biomass, Pt. B), 137-74CODEN: MENZAU; ISSN:0076-6879.A review with 38 refs.
- 44Capanema, E. A.; Balakshin, M. Y.; Kadla, J. F. A Comprehensive Approach for Quantitative Lignin Characterization by NMR Spectroscopy. J. Agric. Food Chem. 2004, 52 (7), 1850– 1860, DOI: 10.1021/jf035282b44https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2cXitValsLw%253D&md5=8916836e151a2635b4ec85f012f095a4A Comprehensive Approach for Quantitative Lignin Characterization by NMR SpectroscopyCapanema, Ewellyn A.; Balakshin, Mikhail Y.; Kadla, John F.Journal of Agricultural and Food Chemistry (2004), 52 (7), 1850-1860CODEN: JAFCAU; ISSN:0021-8561. (American Chemical Society)A detailed approach for the quantification of different lignin structures in milled wood lignin (MWL) has been suggested using a combination of NMR techniques. 1H-13C heteronuclear multiple quantum coherence and quant. 13C NMR of nonacetylated and acetylated spruce MWL have been found to have a synergetic effect, resulting in significant progress in the characterization of lignin moieties by NMR. About 80% of side chain moieties, such as different β-O-4, dibenzodioxocin, phenylcoumaran, pinoresinol, and others, have been identified on the structural level. The presence of appreciable amts. of α-O-alkyl and γ-O-alkyl ethers has been suggested. Although the quantification of various condensed moieties was less precise than for side chain structures, reliable information can be obtained. Comparison of the calcd. results with known databases on spruce MWL structure shows that the suggested approach is rather informative and comparable with the information obtained from the combination of various wet chem. methods. Discrepancies between the results obtained in this study and those previously published are discussed.
- 45Chen, C.-L. Characterization of Milled Wood Lignins and Dehydrogenative Polymerisates from Monolignols by Carbon-13 NMR Spectroscopy. ACS Symp. Ser. 1998, 697, 255– 275, DOI: 10.1021/bk-1998-0697.ch01845https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK1cXltlCmsrk%253D&md5=aab00f0ad55999ad6eec3270939930b6Characterization of milled wood lignins and dehydrogenative polymerizates from monolignols by carbon-13 NMR spectroscopyChen, Chen-LoungACS Symposium Series (1998), 697 (Lignin and Lignan Biosynthesis), 255-275CODEN: ACSMC8; ISSN:0097-6156. (American Chemical Society)Carbon-13 NMR spectroscopy was used to characterize milled wood lignin (I) from spruce (Picea glauca) and Zhong-Yan Mu (Bischofia polycarpa), as well as dehydrogenative polymerizates (DHPs) from monolignols. The anal. of a quant. 13C-NMR spectrum of spruce I showed that this guaiacyl type lignin had 8-8', 8-5', 5-5' and 8-O-4' linkages which were interpreted as approximating 2, 9, 24 and 53 per 100 C9-units, resp., whereas the frequency of 7-O-4' linkages was <3 per 100 C9-units. The frequencies of both 5-5' and 8-O-4' linkages were much higher than values previously estd. The spectrum of the Zhong-Yan Mu I showed that it is a guaiacyl-syringyl lignin with a guaiacylpropane-syringylpropane molar ratio of approx. 86:14. The dehydrogenation polymn. of monolignols is discussed on the basis of the components identified among the reaction products.
- 46Hatcher, P. G. Chemical Structural Studies of Natural Lignin by Dipolar Dephasing Solid-State 13C Nuclear Magnetic Resonance. Org. Geochem. 1987, 11 (1), 31– 39, DOI: 10.1016/0146-6380(87)90049-046https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaL2sXltFOitbk%253D&md5=618d7834274719c46fad8c0d568dc812Chemical structural studies of natural lignin by dipolar dephasing solid-state carbon-13 nuclear magnetic resonanceHatcher, Patrick G.Organic Geochemistry (1987), 11 (1), 31-9CODEN: ORGEDE; ISSN:0146-6380.Lignins from naturally degraded Douglas fir and white oak were examd. by conventional solid-state and dipolar dephasing 13C NMR techniques. The results obtained from both techniques showed that the structure of natural lignins was consistent with models of softwood and hardwood lignin. The dipolar dephasing NMR data provided a measure of the degree of substitution on arom. rings which was consistent with the models.
- 47Sameni, J.; Krigstin, S.; Sain, M. Characterization of Lignins Isolated from Industrial Residues and Their Beneficial Uses. BioResources 2016, 11 (4), 8435– 8456, DOI: 10.15376/biores.11.4.8435-845647https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXhtlSmsLo%253D&md5=a2adb9ac00976e593b7c7328fdc5bb05Characterization of lignins isolated from industrial residues and their beneficial usesSameni, Javad; Krigstin, Sally; Sain, MohiniBioResources (2016), 11 (4), 8435-8456CODEN: BIORCM; ISSN:1930-2126. (North Carolina State University, Dep. of Wood and Paper Science)The physico-chem. properties of lignin isolated from lignocellulosic bioethanol residues and hardwood kraft black liquor were compared with two com. lignins, kraft softwood lignin, and soda non-wood lignin. Lignin from the industrial residues was isolated through the acid pptn. method. The amt. of lignin isolated was approx. 38% of the dry wt. of lignocellulosic bioethanol residues and approx. 27% of the black liquor solids. The nos. of methoxyl groups and phenolic and aliph. hydroxyls were detd. to derive a mol. formula for each of the four lignins. The mol. wts. of the lignins were measured by high performance size exclusion chromatog. Potential value-added applications of the lignins were summarized based on their mol. wts. and physico-chem. characteristics.
- 48Ferrari, A. C.; Robertson, J. Raman Spectroscopy of Amorphous, Nanostructured, Diamond–like Carbon, and Nanodiamond. Philos. Trans. R. Soc., A 2004, 362 (1824), 2477– 2512, DOI: 10.1098/rsta.2004.145248https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2cXhtFahtbrM&md5=18ebdb3a57dcbb6b220d0e652345a254Raman spectroscopy of amorphous, nanostructured, diamond-like carbon, and nanodiamondFerrari, Andrea Carlo; Robertson, JohnPhilosophical Transactions of the Royal Society of London, Series A: Mathematical, Physical and Engineering Sciences (2004), 362 (1824), 2477-2512CODEN: PTRMAD; ISSN:1364-503X. (Royal Society)A review. Raman spectroscopy is a std. characterization technique for any C system. Here the authors review the Raman spectra of amorphous, nanostructured, diamond-like C and nanodiamond. To use resonant Raman spectroscopy to det. structure and compn. of C films with and without N. The measured spectra change with varying excitation energy. By visible and UV excitation measurements, the G peak dispersion can be derived and correlated with key parameters; such as d., sp3 content, elastic consts. and chem. compn. The authors then discuss the assignment of the peaks at 1150 and 1480 cm-1 often obsd. in nanodiamond. The authors review the resonant Raman, isotope substitution and annealing expts.; which lead to the assignment of these peaks to trans-polyacetylene.
- 49Ferrari, A. C.; Robertson, J. Interpretation of Raman Spectra of Disordered and Amorphous Carbon. Phys. Rev. B: Condens. Matter Mater. Phys. 2000, 61 (20), 14095– 14107, DOI: 10.1103/PhysRevB.61.1409549https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD3cXjs1Smu7c%253D&md5=e451e6f21e1f6cf375931e6a23e836bbInterpretation of Raman spectra of disordered and amorphous carbonFerrari, A. C.; Robertson, J.Physical Review B: Condensed Matter and Materials Physics (2000), 61 (20), 14095-14107CODEN: PRBMDO; ISSN:0163-1829. (American Physical Society)The model and theor. understanding of the Raman spectra in disordered and amorphous C are given. The nature of the G and D vibration modes in graphite is analyzed in terms of the resonant excitation of π states and the long-range polarizability of π bonding. Visible Raman data on disordered, amorphous, and diamondlike C are classified in a 3-stage model to show the factors that control the position, intensity, and widths of the G and D peaks. The visible Raman spectra depend formally on the configuration of the sp2 sites in sp2-bonded clusters. In cases where the sp2 clustering is controlled by the sp3 fraction, such as in as-deposited tetrahedral amorphous C (ta-C) or hydrogenated amorphous C (a-C:H) films, the visible Raman parameters can be used to derive the sp3 fraction.
- 50Wei, J.; Geng, S.; Kumar, M.; Pitkänen, O.; Hietala, M.; Oksman, K. Investigation of Structure and Chemical Composition of Carbon Nanofibers Developed from Renewable Precursor. Front. Mater. 2019, 6, 334, DOI: 10.3389/fmats.2019.00334There is no corresponding record for this reference.
- 51Noori, A.; El-Kady, M. F.; Rahmanifar, M. S.; Kaner, R. B.; Mousavi, M. F. Towards Establishing Standard Performance Metrics for Batteries, Supercapacitors and Beyond. Chem. Soc. Rev. 2019, 48 (5), 1272– 1341, DOI: 10.1039/C8CS00581H51https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXislCltb8%253D&md5=88f640aa2b5f14f544030014bd4d3666Towards establishing standard performance metrics for batteries, supercapacitors and beyondNoori, Abolhassan; El-Kady, Maher F.; Rahmanifar, Mohammad S.; Kaner, Richard B.; Mousavi, Mir F.Chemical Society Reviews (2019), 48 (5), 1272-1341CODEN: CSRVBR; ISSN:0306-0012. (Royal Society of Chemistry)Over the past decade, electrochem. energy storage (EES) devices have greatly improved, as a wide variety of advanced electrode active materials and new device architectures have been developed. These new materials and devices should be evaluated against clear and rigorous metrics, primarily based on the evidence of real performances. A series of criteria are commonly used to characterize and report performance of EES systems in the literature. However, as advanced EES systems are becoming more and more sophisticated, the methodologies to reliably evaluate the performance of the electrode active materials and EES devices need to be refined to realize the true promise as well as the limitations of these fast-moving technologies, and target areas for further development. In the absence of a commonly accepted core group of metrics, inconsistencies may arise between the values attributed to the materials or devices and their real performances. Herein, we provide an overview of the energy storage devices from conventional capacitors to supercapacitors to hybrid systems and ultimately to batteries. The metrics for evaluation of energy storage systems are described, although the focus is kept on capacitive and hybrid energy storage systems. In addn., we discuss the challenges that still need to be addressed for establishing more sophisticated criteria for evaluating EES systems. We hope this effort will foster ongoing dialog and promote greater understanding of these metrics to develop an international protocol for accurate assessment of EES systems.
- 52Yu, D.; Goh, K.; Wang, H.; Wei, L.; Jiang, W.; Zhang, Q.; Dai, L.; Chen, Y. Scalable Synthesis of Hierarchically Structured Carbon Nanotube–Graphene Fibres for Capacitive Energy Storage. Nat. Nanotechnol. 2014, 9 (7), 555– 562, DOI: 10.1038/nnano.2014.9352https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXnslGksrk%253D&md5=1f3ce86cac98a92bad907cbe87eb5857Scalable synthesis of hierarchically structured carbon nanotube-graphene fibres for capacitive energy storageYu, Dingshan; Goh, Kunli; Wang, Hong; Wei, Li; Jiang, Wenchao; Zhang, Qiang; Dai, Liming; Chen, YuanNature Nanotechnology (2014), 9 (7), 555-562CODEN: NNAABX; ISSN:1748-3387. (Nature Publishing Group)Micro-supercapacitors are promising energy storage devices that can complement or even replace batteries in miniaturized portable electronics and microelectromech. systems. Their main limitation, however, is the low volumetric energy d. when compared with batteries. Here, the authors describe a hierarchically structured carbon microfiber made of an interconnected network of aligned single-walled carbon nanotubes with interposed nitrogen-doped reduced graphene oxide sheets. The nanomaterials form mesoporous structures of large sp. surface area (396 m2 g-1) and high elec. cond. (102 S cm-1). The authors develop a scalable method to continuously produce the fibers using a silica capillary column functioning as a hydrothermal microreactor. The resultant fibers show a sp. volumetric capacity ≤305 F/cm3 in sulfuric acid (measured at 73.5 mA/cm3 in a three-electrode cell) or 300 F/cm3 in polyvinyl alc. (PVA)/H3PO4 electrolyte (measured at 26.7 mA/cm3 in a two-electrode cell). A full micro-supercapacitor with PVA/H3PO4 gel electrolyte, free from binder, current collector and separator, has a volumetric energy d. of ∼6.3 mWh/cm3 (a value comparable to that of 4 V-500 μAh thin-film lithium batteries) while maintaining a power d. more than two orders of magnitude higher than that of batteries, as well as a long cycle life. To demonstrate that the fiber-based, all-solid-state micro-supercapacitors can be easily integrated into miniaturized flexible devices, the authors use them to power an UV photodetector and a light-emitting diode.
- 53Zhu, M.; Liu, H.; Cao, Q.; Zheng, H.; Xu, D.; Guo, H.; Wang, S.; Li, Y.; Zhou, J. Electrospun Lignin-Based Carbon Nanofibers as Supercapacitor Electrodes. ACS Sustainable Chem. Eng. 2020, 8 (34), 12831– 12841, DOI: 10.1021/acssuschemeng.0c0306253https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXhsFWjs7jO&md5=63d73785b01294997c4fdb625b07b70dElectrospun Lignin-Based Carbon Nanofibers as Supercapacitor ElectrodesZhu, Mengni; Liu, Huan; Cao, Qiping; Zheng, Hao; Xu, Dang; Guo, Haoyu; Wang, Shumei; Li, Yao; Zhou, JinghuiACS Sustainable Chemistry & Engineering (2020), 8 (34), 12831-12841CODEN: ASCECG; ISSN:2168-0485. (American Chemical Society)Lignin shows great potential for carbon-based functional materials and composite material electronics. However, high heterogeneity, poor thermal stability, and low mol. wt. limit the practical application of lignin for fiber-shaped lignin-based materials, esp. in the field of supercapacitors with high energy storage devices. Herein, a simple modification and fractionation strategy is designed to obtain lignin for the prepn. of high-performance lignin-based carbon fibers (CFs). The modification and fractionation process effectively increases the mol. wt. and reduces the heterogeneity of lignin. The introduction of lignin with large mol. wt. and low heterogeneity is conducive to reduce the carbon wt. loss of the precursor fibers, maintain the morphol. of lignin-based CFs, and then significantly improve the sp. surface area and energy storage properties. The sp. surface area and energy storage d. of the obtained lignin-based CFs reach 2042.86 m2/g and 442.2 F/g, resp. This strategy provides a simple and effective method for the prepn. of high-performance, low-cost, and green energy storage materials. A simple modification and fractionation strategy is designed to obtain lignin for the prepn. of high-performance lignin-based carbon fibers.
- 54Schlee, P.; Hosseinaei, O.; Baker, D.; Landmér, A.; Tomani, P.; Mostazo-López, M. J.; Cazorla-Amorós, D.; Herou, S.; Titirici, M.-M. From Waste to Wealth: From Kraft Lignin to Free-Standing Supercapacitors. Carbon 2019, 145, 470– 480, DOI: 10.1016/j.carbon.2019.01.03554https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXhvF2gsb4%253D&md5=c8ac50c9fd71df0200cf5f711d88ffbaFrom Waste to Wealth: From Kraft Lignin to Free-standing SupercapacitorsSchlee, Philipp; Hosseinaei, Omid; Baker, Darren; Landmer, Alice; Tomani, Per; Mostazo-Lopez, Maria Jose; Cazorla-Amoros, Diego; Herou, Servann; Titirici, Maria-MagdalenaCarbon (2019), 145 (), 470-480CODEN: CRBNAH; ISSN:0008-6223. (Elsevier Ltd.)Pure eucalyptus Kraft lignin derived carbon fiber mats were produced based on a model work flow. It covers the prepn. and characterization of the lignin precursor and the carbon materials and its testing in the final application (supercapacitor). Sequential solvent extn. was employed to produce a eucalyptus Kraft lignin precursor which could be electrospun into lignin fibers without any additives. The fiber formation from low mol. wt. lignin is assigned to strong intermol. interactions via hydrogen bonding and π-π-stacking between individual lignin macromols. which gives rise to assocn. complexes in the electrospinning soln. By stabilization in air, carbonization in N2 and an activation step in CO2, free-standing microporous carbon fiber mats could be produced. These fiber mats possess mainly basic oxygen functional groups which proved to be beneficial when tested as free-standing electrodes in sym. supercapacitors. Consequently, the CO2-activated fiber mats showed a high specific gravimetric capacitance of 155 F/g at 0.1 A/g, excellent rate capability with 113 F/g at 250 A/g and good capacitance retention of 94% after 6000 cycles when tested in 6 M KOH electrolyte. Therefore, we conclude that lignin itself is a promising precursor to produce microporous, oxygen functionalized carbon fibers serving as free-standing electrodes in aq. supercapacitors.
- 55Ma, C.; Wu, L.; Dirican, M.; Cheng, H.; Li, J.; Song, Y.; Shi, J.; Zhang, X. ZnO-Assisted Synthesis of Lignin-Based Ultra-Fine Microporous Carbon Nanofibers for Supercapacitors. J. Colloid Interface Sci. 2021, 586, 412– 422, DOI: 10.1016/j.jcis.2020.10.10555https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXitlWmt7zJ&md5=922e784fbf32bf7d947901000345bdacZnO-assisted synthesis of lignin-based ultra-fine microporous carbon nanofibers for supercapacitorsMa, Chang; Wu, Liqiang; Dirican, Mahmut; Cheng, Hui; Li, Junjing; Song, Yan; Shi, Jingli; Zhang, XiangwuJournal of Colloid and Interface Science (2021), 586 (), 412-422CODEN: JCISA5; ISSN:0021-9797. (Elsevier B.V.)Reducing the material size could be an effective approach to enhance the electrochem. performance of porous carbons for supercapacitors. In this work, ultra-fine porous carbon nanofibers are prepd. by electrospinning using lignin/ polyvinylpyrrolidone as carbon precursor and zinc nitrate hexahydrate (ZNH) as an additive, followed by pre-oxidn., carbonization, and pickling processes. Assisted by the ZnO template, the pyrolytic product of ZNH, abundant micropores are yielded, leading to the formation of microporous carbon nanofibers with sp. surface area (SSA) up to 1363 m2 g-1. The av. diam. of the lignin-based ultra-fine porous carbon nanofibers (LUPCFs) is effectively controlled from 209 to 83 nm through adjusting the ZNH content. With good flexibility and self-standing nature, the LUPCFs could be directly cut into electrodes for use in supercapacitors. High accessible surface, enriched surface N/O groups, and reduced fiber diams. endow the LUPCFs-based electrodes with an excellent specific capacitance of 289 F g-1. The redn. of fiber diams. remarkably improves the rate performance of the LUPCFs and leads to a low relaxation time const. of 0.37 s. The high specific capacitance of 162 F g-1 is maintained when the c.d. is increased from 0.1 to 20 A g-1. Besides, the fabricated LUPCFs show exceptional cycling stability in sym. supercapacitors, manifesting a promising application prospect in the next generation of supercapacitors.
- 56Xuan, D.; Liu, J.; Wang, D.; Lu, Z.; Liu, Q.; Liu, Y.; Li, S.; Zheng, Z. Facile Preparation of Low-Cost and Cross-Linked Carbon Nanofibers Derived from PAN/PMMA/Lignin as Supercapacitor Electrodes. Energy Fuels 2021, 35 (1), 796– 805, DOI: 10.1021/acs.energyfuels.0c0251156https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXisFWqtr3L&md5=eea73787eb39e90265f204f3a1452205Facile Preparation of Low-Cost and Cross-Linked Carbon Nanofibers Derived from PAN/PMMA/Lignin as Supercapacitor ElectrodesXuan, Dipan; Liu, Jie; Wang, Dechao; Lu, Zhe; Liu, Qian; Liu, Yuxuan; Li, Shuirong; Zheng, ZhifengEnergy & Fuels (2021), 35 (1), 796-805CODEN: ENFUEM; ISSN:0887-0624. (American Chemical Society)To develop economical and high-performance water electrolyte supercapacitor electrodes, low-cost and cross-linked carbon nanofibers (CNFs) were prepd. with an electrospinning method by using PAN, lignin, and PMMA as precursors. The addn. of lignin not only reduces the cost of the carbon nanofibers but also increases the sp. surface area of the CNFs by removing carbonyls, and phenol functional groups of lignin during thermal treatment. The effect of PMMA addn. was investigated to prep. the optimal candidate for the supercapacitor electrodes. The results showed that the CNFs from PAN, PMMA, and lignin (PPLCNFs-x, x is the content of PMMA in the spinning soln.) showed excellent electrochem. performance in alk. aq. electrolyte. PPLCNFs-0.5g showed specific capacitance of 233 F g1- at 0.5 A g-1, an outstanding stability of 96.8% when it was cycled 50 000 times at 2 A g-1, and it remained 54.5% of rate capability as c.d. raising from 0.5 to 100 A g-1. The outstanding electrochem. performance of PPLCNFs-0.5g is expected as a consequence of the synergistic effect of larger sp. surface area and cross-linked structure. The cross-linked structure ensures rapid transmission of electrons on the carbon nanofiber membrane, and the large sp. surface area is conducive to charge storage. This method offers a new prepn. approach for synthesizing high performance CNFs with low-cost, cross-linked structures.
- 57Kim, M.; Kim, Y.; Lee, K. M.; Jeong, S. Y.; Lee, E.; Baeck, S. H.; Shim, S. E. Electrochemical Improvement Due to Alignment of Carbon Nanofibers Fabricated by Electrospinning as an Electrode for Supercapacitor. Carbon 2016, 99, 607– 618, DOI: 10.1016/j.carbon.2015.12.06857https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC28XhsFaksQ%253D%253D&md5=c7fd76cb84612c8394407f51eb05a332Electrochemical improvement due to alignment of carbon nanofibers fabricated by electrospinning as an electrode for supercapacitorKim, Minjae; Kim, Yeongseon; Lee, Kyung Min; Jeong, Seon Young; Lee, Eunsoo; Baeck, Sung Hyeon; Shim, Sang EunCarbon (2016), 99 (), 607-618CODEN: CRBNAH; ISSN:0008-6223. (Elsevier Ltd.)Aligned carbon nanofibers (CNFs) were fabricated by electrospinning to evaluate the potential of aligned one-dimensional structure as a supercapacitor electrode. First, randomly oriented polyacrylonitrile (PAN) nanofibers were fabricated, and aligned PAN nanofibers were prepd. by increasing the speed of the rotary collector from 250 to 2000 rpm. The prepd. PAN nanofibers were carbonized for use as a supercapacitor electrode. According to increase of speed of collector, the sp. surface area and elec. cond. were improved from 533 to 635 m2 g-1 and from 342 to 626 S cm-1, resp. This result might be caused by increased pulling strength between the fibers and the surface of the collector generated by electrospinning as well as the unique aligned nanostructure of CNFs. The specific capacitance and rate capability of the aligned carbon nanofibers (CNFs) were increased by 35.5 and 28.4%, resp., compared to the randomly oriented CNFs. The enhanced surface area, micropore vol. (from 0.19 to 0.24 cm3 g-1), mesopore vol. (from 0.08 to 0.26 cm3 g-1), and aligned structure make an impact upon the unique electrochem. properties both low scan rate (10 mV s-1) and high scan rate (50 mV s-1).
- 58Jia, K.; Zhuang, X.; Cheng, B.; Shi, S.; Shi, Z.; Zhang, B. Solution Blown Aligned Carbon Nanofiber Yarn as Supercapacitor Electrode. J. Mater. Sci.: Mater. Electron. 2013, 24 (12), 4769– 4773, DOI: 10.1007/s10854-013-1472-z58https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhtlGqsLzL&md5=801a34635c3681d3f6ff113672dd4f0aSolution blown aligned carbon nanofiber yarn as supercapacitor electrodeJia, Kaifei; Zhuang, Xupin; Cheng, Bowen; Shi, Shaojun; Shi, Zhiqiang; Zhang, BoJournal of Materials Science: Materials in Electronics (2013), 24 (12), 4769-4773CODEN: JSMEEV; ISSN:0957-4522. (Springer)Carbon materials with various microtextures and wide availabilities represent very attractive electrode materials for supercapacitors. In this paper, a modified soln. blowing process, using a pair of parallel rods as collector, was reported to fabricate carbon nanofiber yarn (CNFY) with polyacrylonitrile (PAN) as precursor polymer. The morphol. and structure of the nanofibers were investigated. The PAN precursor and carbon nanofibers were well-aligned and their av. diam. was 280 nm and 187 nm, resp. The performance of CNFY as supercapacitor electrode was evaluated. The CNFY possessed high cond. of 608.7 Scm-1 and mass specific capacitance of 70 Fg-1 at the c.d. of 500 mAg-1, and the redn. of capacitance is 29.14 % of the initial value at the c.d. range from 0.5 to 8 Ag-1. The superior performance of the CNFY electrode was attributed to the well-aligned structure and high elec. cond. which afforded the potential application as a novel electrode for supercapacitors.
- 59Zhang, Z.; Bai, B.; Zeng, L.; Wei, L.; Zhao, T. Aligned Electrospun Carbon Nanofibers as Electrodes for Vanadium Redox Flow Batteries. Energy Technol. 2019, 7 (10), 1900488, DOI: 10.1002/ente.20190048859https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXhvVylsrfO&md5=a51965c34b3b8fe691760376ee00cce8Aligned Electrospun Carbon Nanofibers as Electrodes for Vanadium Redox Flow BatteriesZhang, Zhihui; Bai, Bofeng; Zeng, Lin; Wei, Lei; Zhao, TianshouEnergy Technology (Weinheim, Germany) (2019), 7 (10), 1900488CODEN: ETNEFN; ISSN:2194-4296. (Wiley-VCH Verlag GmbH & Co. KGaA)Electrospun carbon nanofibers (CNFs) are regarded as potential electrode materials for vanadium redox flow batteries (VRFBs) due to the advantages of a large surface area and good electrochem. activity. However, woven CNFs with randomly distributed fibers are limited by poor permeability of the electrolyte, thus leading to a large mass-transport polarization during battery operation. To address this issue, aligned carbon nanofiber (ACNF) webs are fabricated and applied in the battery with fibers parallel to the flow channel. Cyclic voltammogram results show that the as-prepd. aligned electrode exhibits better electrochem. activity for both the VO2+/VO2+ and V2+/V3+ redox reactions than that of com. carbon paper (CP) and random electrodes, attributing to its higher surface area and favorable surface activity. The battery with the ACNF electrode achieves higher voltage efficiency (87%, 60 mA cm-2) than that of CP and random electrodes. Moreover, the ordered structure of the aligned electrode further enhances mass transport effectively, thus lowering the concn. loss. The polarization curve measurements also show that the limiting c.d. of the aligned electrode is 25% higher than that of the random electrode. All these results demonstrate that the aligned electrode is promising in VRFBs.
- 60Zhang, Y.; Song, X.; Xu, Y.; Shen, H.; Kong, X.; Xu, H. Utilization of Wheat Bran for Producing Activated Carbon with High Specific Surface Area via NaOH Activation Using Industrial Furnace. J. Cleaner Prod. 2019, 210, 366– 375, DOI: 10.1016/j.jclepro.2018.11.04160https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1cXit1WlsrvJ&md5=b63d1ba9bb71f450de968ec6cf769c3cUtilization of wheat bran for producing activated carbon with high specific surface area via NaOH activation using industrial furnaceZhang, Ying; Song, Xiaolan; Xu, Yue; Shen, Haijing; Kong, Xiaodong; Xu, HongmeiJournal of Cleaner Production (2019), 210 (), 366-375CODEN: JCROE8; ISSN:0959-6526. (Elsevier Ltd.)Waste of wheat bran was used for the first time to prep. activated carbon with high sp. surface area via sodium hydroxide activation. The effects of activation temp. (700-900°C) and NaOH mass ratio (1-5) on surface area were studied. Products were characterized by thermal anal., nitrogen adsorption-desorption, X-ray diffraction, IR spectroscopy, SEM and transmission electron microscopy. One development model was used to explain the evolution of pore structure. The product synthesized at 800°C with mass ratio of 4 possessed the largest surface area of 2543 ± 89 m2/g with low ash content of 0.68 ± 0.03 wt%. For liq. adsorption of methylene blue, the max. adsorption capacity was recorded as 887.3 ± 24.9 mg/g, higher than 663.8 ± 14.8 mg/g for com. coconut shell carbon. Adsorption data were fitted well with the Redlich-Peterson isotherm and pseudo-second order model, closing to surface area. Cost of carbon prodn. using industrial furnace was calcd. as 3.56 ± 0.18 $/kg (reduced 32.4% than tube furnace), with output of 1.28 ± 0.07 kg/d (improved 11.8 times). It could be demonstrated that wheat bran was an effective and sustainable raw material to obtain low cost carbon product with high surface area, indicating its potential utilization.
- 61Carrott, P.; Carrott, M. R.; Suhas Comparison of the Dubinin–Radushkevich and Quenched Solid Density Functional Theory Approaches for the Characterisation of Narrow Microporosity in Activated Carbons Obtained by Chemical Activation with KOH or NaOH of Kraft and Hydrolytic Lignins. Carbon 2010, 48 (14), 4162– 4169, DOI: 10.1016/j.carbon.2010.07.03161https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXhtVyru7zL&md5=5903eb0b591fb30b57d0e7a06d45b74eComparison of the Dubinin-Radushkevich and Quenched Solid Density Functional Theory approaches for the characterisation of narrow microporosity in activated carbons obtained by chemical activation with KOH or NaOH of Kraft and hydrolytic ligninsCarrott, P. J. M.; Ribeiro Carrott, M. M. L.; SuhasCarbon (2010), 48 (14), 4162-4169CODEN: CRBNAH; ISSN:0008-6223. (Elsevier Ltd.)The classical DR method and the Quenched Solid D. Functional Theory (QSDFT) approach have been used to analyze N2 at 77 K isotherms detd. on activated carbons prepd. by alk. chem. activation of different lignins. The QSDFT pore size distributions are bimodal with a narrow peak below 1 nm and a broad peak from 1 to 2.5-3.5 nm. Deconvolution allows estn. of the vols. and widths of the narrow micropores. These are lower than estd. by the DR anal. as this does not sep. micropore and non-micropore adsorption. On the basis of the QSDFT anal., the optimum conditions for obtaining materials with a high vol. of narrow micropores were activation temps. of 550-650 °C, hydroxide/lignin ratio of 1 and dwell time at the max. activation temp. of 30 min. KOH was preferable to NaOH as it requires lower temps. and results in materials with higher narrow micropore vols. The "best" material obtained, prepd. with KOH at 550 °C, had mean micropore width of 0.7 nm and micropore vol. of 0.37 cm3 g-1 which compares very favorably with mol. sieve carbons prepd. from synthetic polymers. Furthermore, this material was obtained with an activation yield of 32.9%, which is quite high for alk. chem. activation.
- 62Ago, M.; Jakes, J. E.; Johansson, L.-S.; Park, S.; Rojas, O. J. Interfacial Properties of Lignin-Based Electrospun Nanofibers and Films Reinforced with Cellulose Nanocrystals. ACS Appl. Mater. Interfaces 2012, 4 (12), 6849– 6856, DOI: 10.1021/am302008p62https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XhsleqtLfP&md5=1404b05d86e59f1f0a9d2d2f821e601aInterfacial Properties of Lignin-Based Electrospun Nanofibers and Films Reinforced with Cellulose NanocrystalsAgo, Mariko; Jakes, Joseph E.; Johansson, Leena-Sisko; Park, Sunkyu; Rojas, Orlando J.ACS Applied Materials & Interfaces (2012), 4 (12), 6849-6856CODEN: AAMICK; ISSN:1944-8244. (American Chemical Society)Sub-100 nm resoln. local thermal anal., XPS, and water contact angle (WCA) measurements were used to relate surface polymer distribution with the compn. of electrospun fiber mats and spin coated films obtained from aq. dispersions of lignin, polyvinyl alc. (PVA), and cellulose nanocrystal (CNC). Defect-free lignin/PVA fibers were produced with radii which were obsd. to increase with lignin concn. and with the addn. of CNCs. XPS and WCA results indicate a nonlinear relationship between the surface and the bulk compns. A threshold around 50 wt % bulk compn. was identified in which extensive partitioning of PVA and lignin components occurred on the surface below and above this value. In 75:25 wt % lignin/PVA solvent cast films, phase sepd. domains were obsd. Using nanoscale thermal analyses, the continuous phase was detd. to be lignin-rich and the discontinuous phase had a lignin/PVA dispersion. Importantly, the size of the phase sepd. domains was reduced by the addn. of CNCs. When electrospun fiber surfaces were lignin-rich, the addn. of CNCs affected their surfaces. In contrast, no surface effects were obsd. with the addn. of CNCs in PVA-rich fibers. Overall, we highlight the importance of mol. interactions and phase sepn. on the surface properties of fibers from lignin as an abundant raw material for the fabrication of new functional materials.
- 63Bennett, A. E.; Rienstra, C. M.; Auger, M.; Lakshmi, K.; Griffin, R. G. Heteronuclear Decoupling in Rotating Solids. J. Chem. Phys. 1995, 103 (16), 6951– 6958, DOI: 10.1063/1.47037263https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK2MXovVeqtLs%253D&md5=ed2b1421bea9403a0dc85d2f51c8a746Heteronuclear decoupling in rotating solidsBennett, Andrew E.; Rienstra, Chad M.; Auger, Michele; Lakshmi, K. V.; Griffin, Robert G.Journal of Chemical Physics (1995), 103 (16), 6951-8CODEN: JCPSA6; ISSN:0021-9606. (American Institute of Physics)A simple two pulse phase modulation (TPPM) scheme greatly reduces the residual linewidths arising from insufficient proton decoupling power in double resonance magic angle spinning (MAS) expts. Optimization of pulse lengths and phases in the sequence produces substantial improvements in both the resoln. and sensitivity of dil. spins (e.g., 13C) over a broad range of spinning speeds at high magnetic field. The theor. complications introduced by large homo- and heteronuclear interactions among the spins, as well as the amplitude modulation imposed by MAS, are explored anal. and numerically. To the authors' knowledge, this method is the 1st phase-switched sequence to exhibit improvement over continuous-wave (cw) decoupling in a strongly coupled homogeneous spin system undergoing sample spinning.
- 64Earl, W. L.; VanderHart, D. Measurement of 13C Chemical Shifts in Solids. J. Magn. Reson. 1982, 48 (1), 35– 54, DOI: 10.1016/0022-2364(82)90236-064https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaL38XktFGqsb4%253D&md5=082b8ac5b581e0a46c38496d462434d2Measurement of carbon-13 chemical shifts in solidsEarl, William L.; Van der Hart, D. L.Journal of Magnetic Resonance (1969-1992) (1982), 48 (1), 35-54CODEN: JOMRA4; ISSN:0022-2364.A pulse sequence and sample geometry which allows the measurement of 13C chem. shifts of solid materials relative to liq. Me4Si (TMS) are described. The chem. shifts of a series of common engineering plastics were measured. A small no. of candidate secondary shift ref. materials were considered and their chem. shifts measured. Most of these materials proved to be unsuitable for general 13C shift refs. for differing reasons. The most promising std. investigated was polydimethylsilane. The measurement of chem. shifts in solid materials is slightly complicated by anisotropic magnetic properties and sensitivity to magic-angle missetting when the material exhibits macroscopic orientation. These complications are discussed in detail and examples of misleading spectra are shown.
- 65Morcombe, C. R.; Zilm, K. W. Chemical Shift Referencing in MAS Solid State NMR. J. Magn. Reson. 2003, 162 (2), 479– 486, DOI: 10.1016/S1090-7807(03)00082-X65https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD3sXks1Wgtrw%253D&md5=7c8d952460e414150384534810791514Chemical shift referencing in MAS solid state NMRMorcombe, Corey R.; Zilm, Kurt W.Journal of Magnetic Resonance (2003), 162 (2), 479-486CODEN: JMARF3; ISSN:1090-7807. (Elsevier Science)Solid state 13C magic angle spinning (MAS) NMR spectra are typically referenced externally using a probe which does not incorporate a field frequency lock. Soln. NMR shifts however, are more often detd. with respect to an internal ref. and using a deuterium based field frequency lock. Further differences arise in soln. NMR of proteins and nucleic acids where both 13C and 1H shifts are referenced by recording the frequency of the 1H resonance of DSS (sodium salt of 2,2-dimethyl-2-silapentane-5-sulfonic acid) instead of TMS (tetramethylsilane). The authors study the difficulties in relating shifts measured relative to TMS and DSS by these various approaches in soln. and solids NMR, and calibrate adamantane as an external 13C std. for solids NMR. External chem. shift referencing of magic angle spinning spectra is typically quite reproducible and accurate, with better than ±0.03 ppm accuracy being straight forward to achieve. Solid state and liq. phase NMR shifts obtained by magic angle spinning with external referencing agree with those measured using typical soln. NMR hardware with the sample tube aligned with the applied field as long as magnetic susceptibility corrections and solvent shifts are taken into account. The DSS and TMS ref. scales for 13C and 1H are related accurately using MAS NMR. Large solvent shifts for the 13C resonance in TMS in either deuterochloroform or methanol are obsd., being +0.71 ppm and -0.74 ppm from external TMS, resp. The ratio of the 13C resonance frequencies for the two carbons in solid adamantane to the 1H resonance of TMS is reported.
- 66Schneider, C. A.; Rasband, W. S.; Eliceiri, K. W. NIH Image to ImageJ: 25 Years of Image Analysis. Nat. Methods 2012, 9 (7), 671– 675, DOI: 10.1038/nmeth.208966https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XhtVKntb7P&md5=85ab928cd79f1e2f2351c834c0c600f0NIH Image to ImageJ: 25 years of image analysisSchneider, Caroline A.; Rasband, Wayne S.; Eliceiri, Kevin W.Nature Methods (2012), 9 (7_part1), 671-675CODEN: NMAEA3; ISSN:1548-7091. (Nature Publishing Group)For the past 25 years NIH Image and ImageJ software have been pioneers as open tools for the anal. of scientific images. We discuss the origins, challenges and solns. of these two programs, and how their history can serve to advise and inform other software projects.
- 67Püspöki, Z.; Storath, M.; Sage, D.; Unser, M. Transforms and Operators for Directional Bioimage Analysis: A Survey. In Focus on Bio-Image Informatics; De Vos, W. H., Munck, S., Timmermans, J.-P., Eds.; Advances in Anatomy, Embryology and Cell Biology; Springer International Publishing: New York, 2016; Vol. 219, pp 69– 93.There is no corresponding record for this reference.
- 68Lundahl, M. J.; Cunha, A. G.; Rojo, E.; Papageorgiou, A. C.; Rautkari, L.; Arboleda, J. C.; Rojas, O. J. Strength and Water Interactions of Cellulose I Filaments Wet-Spun from Cellulose Nanofibril Hydrogels. Sci. Rep. 2016, 6 (1), 1– 13, DOI: 10.1038/srep30695There is no corresponding record for this reference.
Supporting Information
Supporting Information
The Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/acssuschemeng.1c03549.
13C NMR spectra of lignins; molecule size distribution of lignins; magnified OM image of SD solution; illustration of the electrospinning setup; SEM images of as-spun fiber networks; CV plots and GCD curves of CFNs; bending test of the electrode after the electrochemical testing; N2 adsorption isotherms of the CFNs at 77 K; pore size distribution of the CFNs based on nonlocal density functional theory (PDF)
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