Organic photovoltaics have attracted much attention in the past few years, mainly due to their ability to be fully printed at low cost and large scale. However, the organic semiconductors utilized as the active layer are typically synthesized using Migita–Stille or Suzuki–Miyaura cross-coupling, which is not cost efficient and may bring toxicity concerns. In the search for atom-economical synthesis, direct (hetero)arylation polymerization (DHAP) enables the activation of aromatic C–H bonds, both reducing synthetic steps of monomers and toxic reaction byproducts. In this issue, we will discuss the recent contributions on direct (hetero)arylation synthesis toward mass production of photovoltaic materials. The impact of DHAP on material efficiency will be addressed and compared to conventional coupling methods. The ongoing improvements will be discussed, as DHAP becomes more sustainable at higher scale and materials are observed as having higher quality.

The strategy of random terpolymerization has been shown to be a flexible and effective method with which to construct state-of-the-art polymer donors, and chlorination has frequently been utilized to fine-tune material properties in these polymers with the aim of improving the solar conversion efficiency. Herein, three random terpolymers consisting of BDT, BDD, and Th–Cl monomers in the optimized ratio of 1:0.85:0.15 were synthesized in parallel in an effort to understand the effect of chlorination in terpolymer systems and the chlorine-containing derviatives (named PBDB-Th15, PBDB-ThCl15, and PBDB-Th2Cl15). Among these three polymers, PBDB-ThCl15 shows a low-lying HOMO level, the most balanced hole and electron mobility, and enhanced aggregation behavior in blend film as a result of the introduction of one chlorine atom. When blended with a small molecule accepetor Y6, the resulting PBDB-ThCl15:Y6-based device showed the highest PCE of 15.63% of the three polymers. The PBDB-Th15- and PBDB-Th2Cl15-based devices present relatively poor conversion efficiencies of 14.91% and 12.62%. Interestingly, the terpolymer PBDB-ThCl15 was repeatedly prepared by random terpolymerization under the same conditions, and a low batch-to-batch variation was observed with a PCE of ∼15.50%. These results indicate that the synergy of chlorination with random terpolymerization promises to contribute to the preparation of stable and high-performance solar cell polymers.

Two nonfullerene acceptors (TTIDIC and BTIDIC), consisting of indacenodithiophene (IDT) dimers bridged with electron-rich thienothiophene (TT) or electron-accepting benzothiadiazole (BT), were synthesized and compared with their counterpart SIDIC without a bridge to study effects of the bridge nature. Their thin-film absorption spectra and bandgaps are similar. The electron-rich TT bridge slightly up-shifts, whereas the electron-poor BT bridge slightly down-shifts energy levels of the dimers. Both TT and BT bridges enhance the electron mobilities of the dimers. When using polymer J71 as an electron donor, SIDIC-, TTIDIC-, and BTIDIC-based photovoltaic cells show efficiencies of 9.71, 6.54, and 11.5%, respectively. Compared to TT bridge, the BT bridge improves photovoltaic performance of the dimers.

With the recent remarkable advances in the efficiency of organic solar cells, the need to distill key structure–property relationships for semiconducting materials cannot be understated. The fundamental design criteria based on these structure–property relationships will help realize low-cost, scalable, and high-efficiency materials. In this study, we systematically explore the impact of a variety of functional groups, including nitrogen heteroatoms, fluorine substituents, and cyano groups, on benzotriazole (TAZ)-based acceptor moieties that are incorporated into the conjugated polymers. Specifically, a pyridine heterocycle was used to replace the benzene unit of TAZ, leading to the PyTAZ polymer, and a cyano substituent was added to the benzene of the TAZ unit, resulting in the CNTAZ polymer. The PyTAZ polymer suffers from low mobility and poor exciton harvesting, driven by large and excessively pure domains when blended with PCBM. The inclusion of fluorine substituents, placed strategically along the polymer backbone, can mitigate these issues, as shown with 4FT–PyTAZ. However, when this same approach is used for the cyano-functionalized polymer (CNTAZ), the resulting polymer (4FT–CNTAZ) is overfunctionalized and suffers from impure domains and recombination issues. The cyano group has a larger impact on the TAZ core compared to the nitrogen heteroatom due to the strong electron-withdrawing strength of the cyano group. Because of this, further functionalization of the cyano-based polymers has less fruitful impact on the polymer properties and results in deterioration of the solar cell efficiency. Overall, this work highlights some of the benefits, thresholds, and limitations for functionalization of conjugated polymers for organic solar cells.

In this manuscript, we investigate the effect of alkyl side chains of polymer donors on photovoltaic performance of all-polymer solar cells (all-PSCs) based on polymer acceptors containing a boron–nitrogen coordination bond (B ← N). We develop three polymer donors, CD-C12, CD-C16, and CD-C20, with 4,8-di(thiophen-2-yl)benzo[1,2-b:4,5-b′]dithiophen-alt-5,6-difluoro-7-(thiophen-2-yl)-2H-benzo[d][1,2,3]triazole as the main chain and 2-butyloctyl, 2-hexyldecyl, and 2-octyldodecyl as the side chains, respectively. The three polymer donors exhibit similar LUMO/HOMO energy levels and similar absorption spectra. However, they show different aggregation tendency in solution and different solid stacking properties. Among the three polymers, CD-C16 containing medium-length alkyl side chains exhibits the strongest aggregation behavior in solution and much enhanced crystallinity in films. The three polymer donors are blended with a B ← N-based polymer acceptor PBN-14 to prepare all-PSCs. The device of CD-C16 with medium-length alkyl side chains shows small-size phase separation, which leads to a power conversion efficiency (PCE) of up to 9.8%. In comparison, the active layers of CD-C12 and CD-20 show large-scale phase separation and decreased PCEs of the devices. The optimal all-PSC device performance of CD-16 is ascribed to the strong aggregation behavior of polymer backbones in solution and the high crystallinity, which inhibit the oversized crystals of the polymer acceptor and lead to ideal phase separation morphology of the donor/acceptor blend.

Effects of the donor moiety substitution on the intrinsic and photovoltaic blend properties of n-type semiconducting naphthalene diimide-arylene copolymers with donor–acceptor structure were investigated. The alternating naphthalene diimide-thiophene copolymer, PNDIT-hd, and naphthalene diimide-selenophene copolymer, PNDIS-hd, were found to have identical electrochemically derived electronic structures and similar bulk electron mobility; however, PNDIS-hd has an optical bandgap of 1.70 eV, which is 0.07 eV narrower relative to that of PNDIT-hd. All-polymer solar cells incorporating the donor polymer, PBDB-T, and PNDIS-hd were found to combine a high power conversion efficiency of 8.4% with high external quantum efficiency (86%) and a high fill factor of 0.71, which are significantly enhanced compared to the corresponding PBDB-T:PNDIT-hd devices with 6.7% power conversion efficiency and 73% external quantum efficiency. The improved photovoltaic properties of the selenophene-containing acceptor copolymer relative to the thiophene counterpart originate from enhanced light harvesting, more favorable molecular packing in blends, and reduced charge recombination losses in devices. These findings demonstrate that selenophene substitution for thiophene in donor–acceptor copolymers is an effective strategy that enhances the intrinsic polymer properties as well as the performance of all-polymer solar cells incorporating them.

Solar energy conversion has nowadays attracted research interests of the community, wherein conjugated polymers (CPs) become a class of workhorses on photon-to-electron and photon-to-fuel conversion studies. In recent years, exciting breakthroughs have been made in these multi-interdisciplinary fields, with the assistance of the intrinsic flexibilities on tuning optoelectronic, mechanical and structural properties of CPs. In this review, we summarize the recent notable development of CPs in polymer solar cells, perovskite solar cells, and photocatalysts, wherein CPs function well as light-capture and conversion components for polymer solar cells and photocatalysts as well as charge extraction materials for perovskite solar cells. By analyzing the principles, status, and structural-properties of these areas, we outline the design strategies and perspectives of CPs for further advancing solar energy conversions.

A solid epoxy resin formulation containing 2.5 wt % carbon nanotubes is 3D printed into self-standing parts, which after thermal curing result in CNTs/epoxy nanocomposites with mechanical properties attractive for heavy-duty applications.

The electrical conductivity of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) films with four salts that have various cations but the same bis(trifluoromethanesulfonyl)amide (TFSI) anion was studied. We found that doping salts of small-sized cations led to better conductivity because of the improved crystalline order and p-doped level of PEDOT, as revealed by the grazing-incidence wide-angle X-ray scattering (GIWAXS) and UV–vis spectrum. This phenomenon can be rationalized with the fact that small-sized cations with stronger Coulombic interactions can lead to high doping and rearrangement of PEDOT:PSS. These findings will help to develop recipes based on the PEDOT:PSS/salt composite toward the applications for printed flexible electronics.

A thermally cured epoxy/anhydride system is shown to exhibit dose-dependent increases in cross-link density, glass transition temperature, and modulus. The addition of various sensitizers further boosts sensitivity toward radiation-induced cross-linking. A theory proposed by Shibayama relating T_g with cross-link density provides a useful means to predict the dose at which a particular set of properties may be produced. This combination of an approach to materials formulation and processing and the identification of simple analytical models to predict resultant properties provides a useful strategy for the generation of functionally graded materials.

Polydicyclopentadiene (PDCPD) is a thermoset polymer that is valued in industry for its excellent mechanical properties, heat resistance, and chemical tolerance. However, the commercial polymer lacks chemically tunable functionality. Recently, a methyl ester functionalized polydicyclopentadiene (fPDCPD) was shown to offer significantly improved tunability while maintaining the same thermal stability as the unfunctionalized parent polymer. In this report, we describe the synthesis and characterization of poly[(methyl ester functionalized dicyclopentadiene)-stat-(dicyclopentadiene)] copolymers in which the mole fraction of the functionalized, ester-containing monomer, relative to the unfunctionalized dicyclopentadiene monomer, is systematically increased. Our data reveal an ability to tune physical and mechanical properties of the copolymers (e.g., alpha transition and hardness) by changing the monomer ratio and thermal curing time. Importantly, the copolymers retain the same thermal stability as the individual homopolymers, while allowing for increased control over surface energy.

We present a series of polyamide membranes synthesized via molecular layer-by-layer (mLbL) deposition of trimesoyl chloride (TMC) and 3,5-diaminobenzoic acid (BA). These membranes exhibit superior NaCl rejection compared to previously reported TMC–BA membranes prepared via interfacial polymerization with the improved performance of the mLbL films attributable to higher cross-link density facilitated by the stepwise deposition process in good solvents. We compare the TMC–BA series with membranes synthesized from TMC and m-phenylenediamine (MPD), a conventional reverse osmosis membrane chemistry. At the minimum thickness capable of 90% NaCl rejection, mLbL TMC–BA membranes exhibit 50% greater water permeance than mLbL TMC–MPD.

Wearable devices can provide valuable information for the user when completing rehabilitation or attempting to improve athletic performance. Seamlessly incorporated soft strain sensors enable the correlation of strain to more complex metrics such as quantitative multiaxis joint angle motion tracking that is useful for analysis of activities such as walking, running, or cycling. Using a dip-coating technique, a capacitive filament was produced that achieved a relatively high performance with simple materials and fabrication processes. The design of the capacitor produced a sensor with a high baseline capacitance with low noise through the use of a combination of dielectric layers and interfaces between electrodes, good mechanical response through the use of a pristine core filament to support the capacitive sensor components, and a highly stable and reliable signal without requiring exotic or expensive conductive components aided by using specific electronics. The sensor was highly linear within the sensing region required in our proof-of-concept knee brace device, which could predict knee angles to within 1.79° with a simple and easy calibration protocol.

In this study, we propose a simple low-cost emulsion-based method to fabricate porous poly(dimethylsiloxane) (PDMS) adhesive films, with a focus on their possible application as wound dressings. In this method, water is added to PDMS to form an emulsion. On film-casting the emulsion and curing it at 120 °C, evaporation of water droplets and PDMS cross-linking result in randomly distributed pores/voids in the bulk of the PDMS film. A huge advantage of the proposed method over conventional approaches is its simplicity owing to the use of water as a porogen. Two variants of the fabrication approach were considered: direct film-casting of emulsion and film-casting of the solvent-mediated emulsion with additional degassing. Films prepared using the first approach demonstrated that the bulk porosity induces significant roughness at their surface. Such films do not make good contact with the substrate, resulting in poor adhesion. Coating the films with a thin viscoelastic layer of PDMS, while retaining the bulk structure, improves the contact of the film with the substrate. These bi-layer films demonstrated remarkable enhancement in adhesion. The second approach involves adding ethyl acetate as a solvent and degassing the emulsion before film-casting, which results in a more controlled porosity and lower roughness at the surface. Compared to the porous films synthesized using the former protocol, these films have a relatively improved contact with the cover plate, resulting in enhanced adhesion. Lastly, through falling weight impact measurements, it was shown that the porous films, in comparison to their nonporous counterpart, were more effective in absorbing the accidental impact shock, which makes them potentially useful in healthcare applications.

All-atom molecular dynamics simulations were undertaken to study the ion-transport mechanism in poly(ethyl vinyl imidazolium) with different anions: Br^–, BF₄^–, PF₆^–, and Tf₂N^–. Specifically, ion association was analyzed along with the statistics of hopping events at a relatively short time scale, which was defined from the instant the breaking and forming occurred of the ion association. Of some significance was the observation that BF₄^– and PF₆^– exhibited more hopping events than either Tf₂N^– or Br^–. Higher temperature promoted more interchain hopping than intrachain hopping for all the polyatomic anions. At a longer time scale, the diffusivity, dynamic heterogeneity, and stringlike cooperative motion were examined. The dynamic heterogeneity decreased with the size of the counterion. Tf₂N^– had a unique curve shape of the self-part of the van Hove function and a shorter length of stringlike motion. It was confirmed that only a small fraction of the counterions were mobile, and most of the hopping events did not lead to the effective transport. The diffusivity had universal correlation to both the structural relaxation time and the average lifetime of ion association for all the simulated chemistries. For each anion, the linear correlation was more possible between the diffusivity and the inverse of the structural relaxation time.

To achieve a better balance between the refractive index and Abbe number, the thiol-functionalized polyhedral oligomeric silsesquioxane (POSS–SH) was incorporated as both nanoreinforcement and cross-linking reagent into high-refractive index polythiourethane (PTU). The influences of the POSS–SH on the microstructures and properties of PTU were investigated. It is found that all the nanocomposites exhibited a dense network structure and high structural homogeneity even at the POSS–SH loading up to 10 wt %. Besides great improvements in the thermal stability and mechanical property, the nanocomposite containing 1.5 wt % POSS–SH revealed a slight reduction in the refractive index from 1.6568 for neat PTU to 1.6557 but a significant increase in the Abbe number from 28 to 35, accompanied by excellent optical transparency. These results indicate that the covalent incorporation of bifunctional POSS–SH into the PTU network will be helpful for the rational design of advanced optical and optoelectronic materials.

Amorphous solids, which show characteristic differences from crystals, are common in daily usage. Glasses, gels, and polymers are familiar examples, and polymers are particularly important in terms of their role in construction and crafting. Previous studies have mainly focused on the bulk properties of polymeric products, and the local properties are less discussed. Here, we designed a distinctive protocol using the negatively charged nitrogen vacancy (NV^–) center in nanodiamond to study properties inside polymeric products in situ. Choosing the curing of poly(dimethylsiloxane) (PDMS) and the polymerization of cyanoacrylate as subjects of investigation, we measured the time dependence of local pressure and strain in the materials during the chemical processes. From the measurements, we were able to probe the local shear stress inside the two polymeric substances in situ. By regarding the surprisingly large shear stress as the internal tension, we attempted to provide a microscopic explanation for the ultimate tensile strength (UTS) of a bulk solid. Our current methodology is applicable to any kind of transparent amorphous solids with the stress in the order of MPa and to the study of in situ properties in nanoscale. With better apparatus, we expect the limit can be pushed to sub-MPa scale.

Organic cage frameworks (OCFs), one kind of amorphous porous organic polymers with fixed pore size, exhibit great potential in molecular separations and sensing. However, it is a great challenge to control the porous properties of OCFs because of the low yielding for synthesizing the highly stable organic cage monomers. Herein, two organic cage frameworks (OCFs) pCage-1 and pCage-2 were constructed from bicyclooxacalixarene cages Cage-1 and Cage-2, respectively. The pore sizes of both the frameworks pCage-1 and pCage-2 were 5.4 Å because their monomers Cage-1 and Cage-2 have similar intrinsic cavities. Compared with the framework pCage-1, pCage-2 shows significant improvement in porous properties, including the Brunauer–Emmett–Teller (BET) surface area, CO₂ adsorption capacity, and adsorption selectivity of CO₂/N₂, which may be the reason for the introduction of N-doped triazine unit.

Atomic oxygen (AO) attacks carbon-fiber reinforcing polymers on the surfaces of spacecraft in low Earth orbit and threatens safe spacecraft operation and service life. Incorporating phenylphosphine oxide (PPO) groups into polymer chains offers a self-regenerating method of protection from AO but remains poorly understood. Herein, epoxies containing PPO groups were synthesized with increasing concentrations of phosphorus [P] from 0 to 8 wt % to investigate their AO resistance. Thin films of PPO-containing epoxies were exposed to AO via oxygen plasma etching and characterized by interferometry, X-ray photoelectron spectroscopy, and atomic force microscopy─infrared spectroscopy. Measurements confirmed that the exposure of these materials to AO produces a passivation phosphate (PO_x) layer on the surface of the sample, resulting in up to 100X decrease in AO erosion rates. Furthermore, key insights into the relationship between initial [P], passivation layer surface topology, and polymer depth profiles were obtained. Crucially, the results indicate that these materials advantageously did not exhibit linear erosion rates when exposed to AO, in contrast to most organic polymers, and their AO resistance can be readily tuned via synthetic incorporation of monomers with varying [P].

Intrinsic porosity in polymeric materials arises from the formation of a continuous network of interconnected voids and is a direct consequence of the shape and rigidity of the molecular building blocks. To obtain well-defined pores with narrow size distributions, the polymerization of rigid and sterically hindered monomers must not interfere with the pore formation and should avoid the use of additives that may occupy voids. Polydiacetylenes can be generated by the topochemical polymerization of diacetylene-bearing molecules favorably arranged in crystals, gels, thin films, or vesicles. Polydiacetylene formation in amorphous materials has been sparsely studied because higher-order self-assembled structures are assumed to be required for the topochemical polymerization of 1,3-butadiyne to occur. In this study, a bulky hexachlorocyclotriphosphazene core (N₃P₃Cl₆) was functionalized with six diacetylene-containing alkyl chains and successfully converted to an intrinsically porous multifunctional polydiacetylene. The successful formation of the polydiacetylene was confirmed by Raman spectroscopy, and the porous structure of the resulting materials was verified by X-ray diffraction and Brunauer–Emmett–Teller surface area measurements. This investigation revealed a significant change in the porous structure after polymerization, leading to a 5-fold increase in specific surface area. Overall, the topochemical polymerization of diacetylenes is a promising strategy for the preparation of functional materials, which is shown to be compatible with rather amorphous phases of bulky molecules. The results obtained from this investigation give access to a range of porous polydiacetylene materials for potential applications in organic electronics, gas adsorption, and other related fields.

The use of electrically charged, polymerized ionic liquids (polyILs) offers opportunities for the development of gel–polymer electrolytes (GPEs), but the rational design of such systems is in its infancy. In this work, we compare the properties of polyIL/IL GPEs based on 1-butyl-3-(4-vinylbenzyl)imidazolium bis(trifluromethanesulfonyl)imide containing trapped ammonium-based protic ionic liquids (ILs) with an analogous series based on the electrically neutral host polymer 1-(4-vinylbenzyl)imidazole. The materials are synthesized by photopolymerizing ionic and neutral monomers in the presence of diethylmethylammonium trifluoromethanesulfonate, [dema][TfO], diethylmethylammonium trifluoroacetate, [dema][TFAc], and diethylmethylammonium bis[trifluoromethanesulfonyl]imide, [dema][Tf₂N], respectively. The resulting materials are characterized using electron microscopy, infrared spectroscopy, thermal analysis, Raman spectroscopy, and AC-impedance analysis. Spectroscopic analysis confirms that the ILs are distributed throughout the polymers, unless the GPE also contains poly(diallyldimethylammonium) bis[trifluoromethanesulfonyl]imide, when separation of the components occurs. The polyIL/IL GPEs are more electrochemically and thermally stable, and up to six times more conductive, than the materials based on the neutral host. As a proof-of-concept demonstration, we show that polyIL/IL gels can be 3D printed using readily available 3D-printing hardware.

Great advances have been made in the development of porous materials for efficient iodine capture. Among them, introducing high-affinity binding sites (such as heteroatoms) to improve iodine uptake is a promising strategy. However, systematic research on the heteroatom effect for iodine capture, which may be helpful in clarifying the adsorption process and designing materials with excellent performance, has been rarely reported. In this study, seven hyper-cross-linked porous polymers (HCPs) containing boron, nitrogen, and sulfur atoms, individually or in combination, were synthesized. Based on the experimental evidence and computational simulations, it can be concluded that surface area and pore accessibility are important factors for improving iodine capture capacities and that doping heteroatoms can influence the affinity between HCPs and iodine and then influence the pore accessibility of the materials.

Ceramic/polymer composite with a high thermal conductivity is a candidate of insulating materials for electronic packaging. However, traditional polymer composites filled with alumina (Al₂O₃) powders present limited enhancement in thermal conductivity even at a high loading due to thermal resistance on the filler/filler and filler/matrix interfaces. Herein, a contiguous 3D network of alumina foam (AF) filled with different diameters of Al₂O₃ microparticles via vacuum-assisted filtration proves to be a promising filler structure for thermal conductivity composites. The fabricated epoxy/AF/Al₂O₃ composite exhibits a high thermal conductivity of 4.1 W/mK and a significant thermal conductivity enhancement (TCE) of 2097%. Further study reveals a prominent synergistic effect between the 3D interconnected AF and Al₂O₃ microparticles, which plays a critical role in the formation of thermal percolation networks to promote thermal conductivity dramatically. Meanwhile, compared to previous reports, the composite resulted in a lower coefficient of thermal expansion (CTE) than those of most epoxy-based composites, showing great potential for heat conduction applications in microelectronics. This result paves an effective way of developing epoxy composites with high thermal conductivity in electronic packaging applications.

We developed molecularly imprinted polymers (MIPs) with a poly(ethylene glycol) (PEG)-based cross-linker and boronic acids in functional monomers, which selectively form a complex with a diol structure for selective removal of lactones from a coffee beverage. We synthesized a boronic acid monomer, 1-allylpyridinium-3-boronic acid, which has lower pK_a and stronger binding strength to saccharides than commonly used boronic acids. Then, we prepared the MIPs with the monomer and succeeded in selective adsorption for a type of lactones, quinic acid gamma-lactone (QAGL). Furthermore, the high hydrophilicity of PEG and the molecular imprinting effect prevented an un-specific adsorption of other components in coffee. Finally, we achieved in removal of QAGL in coffee with high yield and at high speed by using the MIP-based microsphere as a separation medium in solid-phase extraction. This study provides a simple method for better-tasting freshly brewed coffee.

The challenge in achieving extreme wetting (<10° contact angle) in engineering polymer surfaces lies in the balance between water-loving chemical compositions and the degrading effects of absorbed water on physical, thermal, and mechanical properties. Hydrophobic recovery caused by surface energy minimization and surface polymer chain relaxation also contributes to the challenges in achieving stable extreme wetting in thermoplastic polymers. In this report, multiscale topography consisting of random nanoporous structure and uniform micropattern presents an extended capillary network to achieve superwetting on thermoplastic polymers. The topography that results in a buried pore structure achieves two design objectives: (1) an extended surface area that is shielded from surface contamination by the small pore size and tortuous path into the coating thickness and (2) an extended path for wicking of liquid into the coating to achieve long-lasting superhydrophilic performance. Nanoporous poly(methyl methacrylate) (PMMA) coatings on microtextured substrates exhibit superhydrophilic performance through a two-phase contact angle decline. Nanoporous PMMA on 1 μm grating and 500 nm pillar arrays yielded the best and most robust superhydrophilic wetting with a measured water contact angle of near 0°, a complete spreading state over a test period of 48 h and over multiple rewetting tests.

We present a photocurable, biocompatible, and flexible silicone-hydrogel hybrid material for stereolithographic (SLA) printing of biomedical devices. The silicone-hydrogel polymer is similar to mixtures used for contact lenses. It is flexible and stretchable with a Young’s modulus of 78 MPa and a maximum elongation at break of 51%, shows a low degree of swelling (<4% v/v) in water, and can be bonded easily to flat glass substrates via a surface-modification method. The in vitro cytotoxicity of the material is assessed with a WST-8 cell viability assay using five different cell lines: HT1080, L929, and Hs27 fibroblasts, cardiomyocyte-like HL-1 cells, and neuronal-phenotype PC-12 cells. On this account, the silicone-hydrogel polymer is compared to several other common SLA printing materials used for cell-culture applications and polydimethylsiloxane (PDMS). A simple extraction step in water is sufficient for reaching biocompatibility of the material with respect to the tested cell types. The oxygen permeability of the silicone-hydrogel material is investigated and compared to that of PDMS, Medicalprint clear─a commercial resin for medical products, and a short-chain hydrogel-based resin. As a proof of concept, we demonstrate a 3D-printed microfluidic device with integrated valves and mixers. Furthermore, we show a printed culture chamber for analyzing signal propagation in HL-1 cardiomyocyte cell networks. Ca²⁺ imaging is used to observe the signal propagation through the cardiac cell layers grown in the microchannels. The cells are shown to maintain normal electrophysiological activity within the printed chambers. Overall, the biocompatible silicone-hydrogel material will be an advancement for SLA printing in cell-culture and microfluidic lab-on-a-chip applications.

Epoxy resins with enhanced thermal conductivity are in great demand to improve the thermal management of electrical motors. However, the thermal conductivity of epoxy resin is typically low, comparable to 0.2 W/(m K), and a predictive understanding of the connection between molecular structure and thermal conductivity is not yet established. In this work, we present data for the thermal conductivity of seven thermosets synthesized from one commercially available diepoxide (resorcinol diglycidyl ether) and seven phenylenediamines to systematically examine the dependence of thermal conductivity on the molecular structure of the phenylenediamine hardener. Variations in the molecular structure of phenylenediamines, for example, positions of amine groups and the addition of an electron-withdrawing group, produce up to a factor of 2 change in the thermal conductivity of the cured resins. The highest thermal conductivity of 0.27 W/(m K) is obtained with 5-chloro-m-phenylenediamine; the lowest thermal conductivity of 0.14 W/(m K) is obtained with o-phenylenediamine. Thermal conductivities of these seven epoxy resins are 10–40% lower than the prediction of the minimum thermal conductivity model.

This work aims to provide effective strategies and practical tools to control the diameter of fibers, a long-lasting challenge in the application of free surface melt electrospinning, mainly by highlighting the importance of the solidification point. A systematic approach to mapping the solidification point and temperature profile in an electrohydrodynamic jet in the melt electrospinning process was developed experimentally through the backlit imaging technique and numerically through computational fluid dynamics. The effect of the different spin-line temperature profiles on the robustness of the process as well as the fiber morphology was investigated. Scanning electron microscopy analysis demonstrated that at high spin-line temperature profiles, the fiber diameter dropped by four times compared to the room temperature spin-line environment. Both in situ backlit images from the jets in the spin line and the numerical phase fraction analysis revealed an immediate solidification of the jet, which is elongated twice in the case of the high spin-line temperature profiles. The elongated freezing length for the high spin-line temperature profiles as a result of the delayed solidification was identified as one of the main factors contributing to the jet thinning and subsequent fiber diameter reduction. Based on the simulation, the temperature profile of the jet demonstrated an approximately 20 °C drop along the jet length in the nonsolidified portion (freezing length), proposing the viscosity drop as a second factor in the fiber diameter reduction mechanism. Ultimately, the molten film thickness on the plate was identified as a semiphysical confinement parameter, controlling the size of the formed cones and subsequently the fiber diameter, despite the free surface nature of the unconfined melt electrospinning.

Nanoscale control over pore surface properties is a challenging objective for nanopore research and could enable advanced bioanalytical applications, along with enhanced precision and accuracy of existing measurement processes. This work reports a one-pot strategy for the functionalization of thermoplastic polyurethane (TPU) tunable nanopores with polymer brushes. These elastomeric pores are used for tunable resistive pulse sensing (TRPS), which can detect and analyze a broad range of microparticle and nanoparticle species in aqueous electrolytes. Grafting is achieved using the recently developed Graftfast method, via the chemical reduction of diazonium salts. The study focuses on Graftfast of negatively charged poly(acrylic acid) (PAA) brushes. The method is further exemplified through the grafting of neutral brushes with a view to utilizing their possible antifouling properties: zwitterionic poly(sulfobetaine), 2-hydroxyethyl methacrylate, and poly(ethylene glycol) methyl ethermethacrylate. The successful TPU functionalization was characterized using Fourier transform infrared spectroscopy, contact angle measurements, and X-ray photoelectron spectroscopy. For PAA-grafted pores, the TRPS configuration was used for studies of ionic current rectification, streaming potential, and resistive pulse durations for 500-nm-diameter carboxylated polystyrene spheres. Results were consistent with increased negative surface charge on the pore walls, confirming successful pore functionalization.

In high-resolution stereolithography, printed parts deviate significantly from the projected photomask because of the reaction complexity on the voxel scale. To better understand the reaction process, we have developed a technique to measure local photopolymerization rates using a nanocylinder-tipped atomic force microscope cantilever. The drag force experienced during cantilever oscillations can be correlated to the viscosity and extent of reaction. Fluid dynamics simulations show micrometer-scale measurement localization, and the resonance-based measurement allows submillisecond temporal resolution. In a thiol–ene resin exposed to patterned light, oligomer diffusion length scales are significant compared to the size of printed structures. Consequently, part resolution is dictated by the competition between polymerization and diffusion. Because of the radical polymerization mechanism, increasing the light intensity at a constant dose decreases the local conversion, even though the diffusion length decreases. In the case of printed test structures with features matching the measured diffusion lengths, increased light intensity causes increased geometric aberration from the projected mask. Overall, the results indicate a need for enhanced control over polymerization and diffusion to obtain dimensionally accurate and mechanically homogeneous parts.

Poly(lactic acid) (PLA) is a well-known sustainable plastic but with an inherent brittleness, slow crystallization rate, and poor heat resistance, which significantly limits its application. In this work, toughened PLA with a balanced tensile strength, fast crystallization rate, and great heat resistance was obtained by dynamic vulcanization with an unsaturated liquid crystalline polyester (PBDPSM) in the presence of a free radical initiator of dicumyl peroxide (DCP). PBDPSM is efficient in enhancing the tensile toughness of PLA in that the elongation at break of PLA significantly increased from 15 to 179% while adding only 1 wt % PBDPSM. When adding 8 wt % PBDPSM, the PLA/PBDPSM8 blend has an elongation at break of 265%, tensile toughness of 107.2 MJ/m³, and notched Izod impact strength of 22.5 kJ/m². Moreover, it keeps a high tensile strength of 62.6 MPa. In addition, the crystallization rate of PLA has dramatically accelerated due to the apparent nucleation effect induced by DCP and PBDPSM. PLA/PBDPSM3 shows the highest crystallinity with 44.4%. Furthermore, it shows a high Vicat softening temperature of 152.2 °C, which is 92.2 °C higher than that of neat PLA. Finally, highly toughened PLA materials with balanced tensile strength and good heat-resistant properties were realized.

Herein, we present a scalable and economic synthesis of covalent organic microspheres, a highly cross-linked microspherical polymer, through a single step process. The as-synthesized imine-linked microspherical polymer (TATF-COM) was successfully dressed with Ag nanoparticles and characterized by various spectroscopic-cum-analytical techniques, demonstrating high thermal and chemical stability. The potent catalytic behavior of as-prepared Ag@TATF-COM was evaluated for the catalytic hydrogenation of nitroaromatics (toxic pollutants) in water along with efficient synthesis of substituted imidazoles and exhibited intriguing catalytic activity with encouragement for reusability. The rate constant and Gibbs free energy for catalytic hydrogenation reaction were calculated to be 0.0226 s^–1 and 83.702 kJ/mol, suggesting that the reaction is endothermic, endergonic, and nonspontaneous in nature. We accentuate the significance of shape specific property of COMs that provide a spherical morphology with high surface-to-volume ratio for uniform dressing of Ag nanoparticles. Moreover, we envisage a “catch–react–release” model to explain the catalytic process and investigated in light of experimental results. Thereafter, we have also studied the catalytic efficiency of Ag@TATF-COM in synthesis of substituted imidazoles and observed that as-prepared catalyst showed promising performance for organic transformations. In this, Ag@TATF-COM shows its advantage over previously published work.

Lead zirconate titanate and polydimethylsiloxane (PZT–PDMS) thin films are an attractive choice for a flexible piezoelectric substrate. In this work, the surface modification of the PZT–PDMS composite with plasma treatment is developed to fabricate flexible conductor patterns or devices directly on the composite surface. Optimized plasma treatment conditions are achieved by varying plasma parameters such as the pressure of treatment, type of gas, gas flow, and time of treatment. Plasma polymerization is carried out using C₂H₄–CO₂, and argon (Ar) is used for the surface ablation effect in low-pressure conditions. Atmospheric pressure plasma (APP) is performed in a N₂ atmosphere which has a surface etching effect. All the treatments create a hydrophilic layer, which is confirmed with water contact angle measurements, X-ray photoelectron spectroscopy, and Fourier transform infrared analysis. Silver conductive ink was printed on the plasma-treated films to fabricate flexible conductive patterns, and the bonding strength was tested by performing adhesive tests such as tape, ultrasonic, and soak tests. APP treatment under a N₂ environment with a 300 V input voltage, 21.5 kHz frequency, and 2 min deposition time proves to be the most efficient surface modification technique. This treatment produces a silica-like layer on the composite surface and results in better wettability. It reduces the contact angle from 108 to 20° immediately after the treatment and shows strong adhesion during several rigorous adhesion tests. The printed conductive patterns on the N₂-treated film show strong mechanical stability and exhibit great electric conductivity under bending and releasing. The APP treatment under N₂ environment can overcome the adhesion issue of the printed conductive layer on the hydrophobic composite surfaces. Moreover, all the above plasma treatments have a negligible effect on the piezoelectric properties of PZT–PDMS films.

The use of highly cross-linked molecularly imprinted polymers as a synthetic target receptor has the limitations of restricted accessibility to the binding sites, resulting in a slow response time. Moreover, such artificial receptors often require additional transduction mechanisms to translate target binding events into measurable signals. Here, we propose the development of a single-chain stimuli-responsive templated polymer, without using any covalent interchain cross-linkers, as a target recognition element. The synthesized polymer chain exhibits preferential binding with the target molecule with which the polymer is templated. Moreover, upon specific target recognition, the polymer undergoes conformation change induced by its particular stimuli responsiveness, namely, the target binding event. Such templated single-chain polymers can be attached to the electrode surface to implement a label-free electrochemical sensing platform. A target analyte, 4-nitrophenol (4-NP), was used as a template to synthesize a poly(N-isopropylacrylamide) (PNIPAM)-based copolymer chain which was anchored to the electrode to be used as a selective receptor for 4-NP. The electrode surface chemistry analysis and the electrochemical impedance study reveal that the polymer concentration, the interchain interactions, and the Hofmeister effect play a major role in influencing the rate of polymer grafting as well as the morphology of the polymers grafted to the electrode. We also show that the specific binding between 4-NP and the copolymer results in a substantial change in the charge transfer kinetics at the electrode signifying the polymer conformation change.

Highly monovalent/bivalent anion permselectivity of anion exchange membranes (AEMs) is of great relevance for a wide range of applications, especially in electrodialysis (ED). In this study, two series of long-side-chain-type AEMs with different microstructures were designed by a facile one-step or two-step Menshutkin reaction. It is found that varying the hydrophobicity of the side chains is a feasible method to easily regulate the permselectivity of AEMs, which was achieved by changing the length of the side chain and charge numbers in long side-chain grafting to the polymer backbone. The CMPSF-N16-1 AEM (ion exchange capacity (IEC) ≈ 1.1 mmol·g–1) exhibits the highest permselectivity (PSO42–Cl– of 60.1), low water uptake (3.5%), and high membrane surface resistance, which are attributed to its hydrophobic polymer backbone and longest alkyl chains. As the IEC of the prepared AEMs augmented or increased the charge numbers in the side chains, PSO42–Cl– obviously decreased, which can be ascribed to the enhanced electrostatic effect and hydrophobicity changes. This work demonstrates that the proposed method to regulate the membrane hydrophobicity is effective to guide the preparation of AEMs with enhanced permselectivity from the microstructure design.

We present a series of bisimidazole-based conjugated porous organic polymers (POPs) (BisImi-POP@1–6), which were formed by the CuI(I)–KOH/KOH-catalyzed cross-coupling reaction between the 2,2′-bisimidazole monomer and aryl halides. For iodine capture, the resultant POPs with a large number of imidazole N-heterocycle units in the skeletons can be used as effective adsorbents, which exhibit high iodine capture capacities of 9.50, 10.30, 4.83, 6.45, 3.57, and 3.93 g g^–1 for BisImi-POP@1, BisImi-POP@2, BisImi-POP@3, BisImi-POP@4, BisImi-POP@5, and BisImi-POP@6, respectively. This is the second report of 2,2′-bisimidazole liquid complexes of the cationic backbone of the POPs and polyiodides as far as we know. Compared with previous solid iodine adsorbents, porous materials based on imidazole and its derivatives show unique properties when they are used as adsorbents for capturing radioactive iodine. This work studied the relationship between the iodine adsorption properties of imidazole-based polymers and the content of imidazole nitrogen heterocycles.

The relationships between the structure and the dielectric properties of polyimides (PIs) were extensively studied to construct universal correlations of dielectric constant (D_k) and dissipation factor (D_f) on the structural parameters. In this study, 36 kinds of PIs with a plethora of functional groups including ether, fluorine, amide, ester, ketone, sulfide, sulfone, and alkane groups were prepared by polyaddition and thermal imidization. Accordingly, their thermal, mechanical, and dielectric properties were systematically investigated. The experimental results showed highly correlated relationships between the D_k values and two structural parameters of fluorine content (F%) and volume polarizability (P/V) with a correlation coefficient of 0.98 and 0.90, respectively. Likewise, the D_f value was highly correlated to the imide group content (Imide%) with a correlation coefficient of 0.95. However, a multiple positive trend was found in the relationship between the D_f values and the volume dipole moment (μ/V) for the PIs. The discrepancy might be resulted from the difficulty to elucidate local molecular motions in the unit structure of PIs. Nevertheless, the D_f values still presented a nontrivial relation to the orientational polarization and dipole moment of the unit structures. Collectively, our experimental results revealed the structure–dielectric properties relationships of the PIs by rational definition on a series of structural parameters and warrant further investigation. Meanwhile, this work provides systematic guidelines for molecular structure design of PIs which are promising for high frequency applications on the fifth-generation (5G) mobile communications technology.

Bio-based flame retardants (FRs) were employed to successfully reduce the flammability of acrylonitrile–butadiene–styrene (ABS), achieving results comparable to a commercial brominated ABS product (Br-ABS); synergistic interactions between the components were responsible for the enhanced performance. In a two-phase study, eight nonhalogenated, low-toxicity FRs and combinations thereof were melt-processed with ABS at a 30 wt % FR content and screened using microscale combustion calorimetry (MCC). All 30 samples presented significantly lower peak heat release rates (PHRR; 26–43% reduction) and total heat release (THR; 16–29% reduction) than ABS. Four best-performing compositions─ABS/tannic acid (TA), ABS/tannic acid/fish gelatin (TA-FG), ABS/phytic acid sodium salt (PA), and ABS/phytic acid sodium salt/tannic acid (PA-TA)─were scaled up and further analyzed through cone calorimetry (CC) and mechanical testing. TA, TA-FG, PA, and PA-TA significantly lowered ABS’s PHRR in MCC (36–43% reduction) and in CC (38–65% reduction). Some samples matched commercial brominated ABS: TA in MCC and PA-TA in CC. The mechanical performances of the composites were acceptable, with an increase in modulus but a loss in toughness. Important synergistic interactions between the FRs and the ABS matrix, between TA and FG, and between PA and TA, were responsible for the reduced flammabilities.

In this work, a series of shape memory biopolymers based on a dual-phase poly(lactic acid) and poly(hydroxybutyrate)-rubber copolymer (PLA/PHB-rubber) were developed, exhibiting significant flexibility and well-balanced shape memory (SM) performance. The incorporation of PHB-rubber emerged as numerous well-dispersed microsized domains that partially penetrated the PLA domain, as revealed by the reduction of glass-transition temperature in the differential scanning calorimetry (DSC). The overall increase in crystallinity with the increasing PHB-rubber contributed to a high shape fixity of ∼99% and recovery of ∼95%, where the crystalline domains of PLA and PHB regions constituted as effective anchors for shape fixing, while the rubbery segment that constituted the switching phase provides considerable chain crusade. Concurrently, the PHB-rubber phase promotes considerable interfacial interaction with the PLA phase, as revealed by the field-emission scanning electron microscopy (FESEM) studies. Remarkably, the macroscopic triple-coiled shape recovery was accomplished in just 3 s. The developed dual-phase binary polymer shows great potential as a shape memory polymer for biomedical applications.

In recent years, photopolymerization has found wide applications in industry and daily life, especially 3D printing. However, some defective properties of photopolymers limit their development, such as their mechanical properties, density, compressive strength, and functionality. Herein, in this work, we reported the fabrication of composites containing seven different kinds of zeolites used as fillers under mild photopolymerization conditions (LTA-5A was selected as the benchmark zeolite), that is, visible LED light irradiation at room temperature under air. The filler properties affecting the related depth of cure and the enhanced mechanical (the storage modulus increased by 10-fold compared to that of a pure polymer) and functional properties were examined in detail. In addition, the production of 3D patterns was performed through direct laser writing (DLW) as a lithography technique. As a real breakthrough, the 3D printing of zeolite/polymer composites is presented here for the first time with high filler contents (up to 75 wt %) using this stereolithography approach. 4D behavior can be established in the presence of water, that is, the 3D object can change the shape and return to the starting geometry after desiccation. Remarkably, after debinding of the composites by thermal treatment, a high zeolite porosity can be regenerated. Therefore, the 3D printing of zeolites is possible in two steps: (i) photopolymerization of organic/zeolite composites to generate the desired shape, followed by (ii) removal of the organic part by thermal treatment. This work is expected to lead to valuable developments in the field of photopolymerization reactions in highly filled composites (with the filler content exceeding 50 wt %) and thereby expand their potential application for 3D or 4D printing in the fields of, for example, high-performance light-weight materials and adsorption.

Light- and temperature-responsive poly(N-isopropylacrylamide-co-nitrobenzyl methacrylate) (pNIPAm-co-NBMA) microgels were synthesized via free-radical precipitation polymerization and exhibited a hydrodynamic diameter of 320 ± 40 nm. We demonstrated that the microgels’ NMBA groups were cleaved upon UV irradiation, which we showed could be used for light-activated release of fluorescein (used as a model drug molecule). Moreover, drug release could also be promoted by microgel deswelling due to heating. Specifically, the hydrophobic model drug fluorescein was incorporated into the pNIPAm-co-NBMA microgels via physical interactions, and we showed that exposure to UV light (or heating) could induce its release. Thus, the pNIPAm-co-NBMA microgels could find the use for applications requiring triggered release of cargo when needed.

Two series of α-1,3-glucan with branched and linear mixed ester side chains, namely α-1,3-glucan pivalate hexanoate (α-1,3-glucan-Pi-Hex) and α-1,3-glucan isobutyrate hexanoate (α-1,3-glucan-iBu-Hex), were synthesized as biomass-based thermoplastic resins via an enzymatic polymerization and a heterogeneous chemical esterification using trifluoroacetic acid anhydride and carboxylic acids. The degree of substitution (DS) ratio of two types of ester groups was precisely controlled by adjusting the initial dosages of the two corresponding carboxylic acids. Although α-1,3-glucan homobranched esters, i.e., α-1,3-glucan pivalate and α-1,3-glucan isobutyrate, were crystalline and their cast films were brittle, the cast films of the mixed esters gradually lost crystallinity and finally became amorphous in proportion to increasing DS of hexanoate (DS_Hex), and their flexibility improved significantly. Specifically, α-1,3-glucan-Pi-Hex and α-1,3-glucan-iBu-Hex with DS_Hex = 1.5 had high film flexibilities and high glass-transition temperatures of 120 and 93 °C, respectively. These are comparable to the properties of conventional oil-based amorphous plastics such as polystyrene and poly(methyl methacrylate). The processing window widened with increasing DS_Hex, which led to less thermal decomposition during thermal processing. The mixed ester method was effective for controlling the physical properties of α-1,3-glucan esters. Furthermore, α-1,3-glucan-Pi-Hex and α-1,3-glucan-iBu-Hex showed promise as transparent and flexible films with high thermal stability for electric devices of designability.

Composites based on fully bio-based epoxy-amine resins reinforced with recycled carbon fibers were obtained and compared to petro- and partially bio-based benchmark materials. Rheology measurements showed that fully bio-based resins are better suited for resin infusion processes as they have higher gel-point temperatures than the benchmark formulations. Thermogravimetric analyses demonstrated that the resin thermal resistance was increased in the presence of recycled fibers. Dynamic mechanical analyses showed that the glass transition temperatures of fully bio-based composites are higher by 30 °C than other reported bio-based materials, making them better suited for industrial applications. Fully bio-based composites exhibited an improvement of mechanical properties between 5 and 85% compared to the benchmark materials. Indeed, a better fiber wetting behavior was observed by scanning electron microscopy analyses, enhancing fiber–matrix interfaces, resulting in higher mechanical behavior. This unprecedented work highlights fully bio-based epoxy-amine resins reinforced with recycled carbon fibers as a realistic low carbon-footprint alternative for functional applications.

A starch-graft-poly(butyl acrylate/styrene) (St-g-PBAS) copolymer was synthesized via grafting butyl acrylate (BA) and styrene (S) monomers onto starch by radical polymerization, and ammonium persulfate (APS) was used as an initiator. Thermochromic St-g-PBAS fibers with a full core structure were achieved through a wet-spinning process via coagulating a dope-dyed St-g-PBAS/dimethylacetamide (DMAc) solution in water. The effects of spinning conditions such as temperature and the drawing rate in a coagulation bath, drawing and stretching multiples of the primary fiber in hot water, thermal setting temperature, and time on the finished fiber mechanical performances were examined. The St-g-PBAS copolymer was analyzed by Fourier transform infrared spectra (FT-IR), solid-state nuclear magnetic resonance (¹³C NMR), thermal gravimetric analysis (TG), and X-ray photoelectron spectroscopy (XPS). The fiber performances were characterized by a scanning electron microscope (SEM), X-ray diffraction (XRD), and a fiber mechanical determinator. The results showed that the substitution degree of starch was 0.51, and the obtained St-g-PBAS fiber had the full core structure and excellent mechanical performances with high breaking strength (up to 2.11 cN·dtex^–1), thermal stability, and elasticity (breaking elongation of up to 88.2%). The fiber color changes repeatedly between purple and pink as the temperature increases and then decreases to 31 °C.

The advent of the COVID-19 pandemic has generated an increased consumption of personal protective equipment (PPE), including gloves and masks, by healthcare workers and by the general public at a global scale. This has generated substantial shortage of these single-use and disposable PPEs that will end up as a landfill waste. Extending the life cycle of PPEs, such as gloves, by disinfecting treatments could help mitigate these concerns. However, the effect of various disinfection treatments on the functionality of gloves is unknown. In this study, six commonly used viral disinfection treatment methods (i.e., ultraviolet (UV) radiation, dry heat, steam, alcohol, chlorine compounds, and quaternary ammonium compounds) were evaluated for their effect on the performance attributes of two commonly used medical-grade gloves and nitrile and vinyl (latex) gloves. The barrier properties of both gloves against water and ethanol vapor flux were not affected up to 10 cycles of disinfection cycles. However, the increase in the disinfection cycle from 10 to 20 slightly reduced their barrier properties with minor variation in the type of disinfection and glove type. Infrared spectroscopy and microscopy investigations confirmed that both types of gloves could withstand up to 20 cycles of disinfection treatments with no observable change in the chemical structure and surface morphology of the disinfected surfaces, respectively. Lastly, tear property testing of the gloves indicated little to no change from the baseline after 20 cycles of treatment in both the nitrile and vinyl-based gloves. Overall, this study indicated that alcohol, UV, and heat treatment could be acceptable disinfection methods that allow the reuse of gloves up to 20 cycles. Such repeated disinfection of gloves not only reduces the strain on the supply of gloves but also decreases the postconsumer landfilled waste and environmental footprint of gloves.

Aerogels comprising poly(3-hexylthiophene) (P3HT) nanofibers dispersed in polystyrene (PS) were fabricated by freeze-drying, doped with iodine vapor, and subjected to thermoelectric property analysis, which revealed that the aerogel structure facilitated quite low thermal conductivity for temperature gradient preservation, while the P3HT nanofiber network percolating the aerogel bulk acted as an effective conductive structure. The highest Seebeck coefficient (S) of >10 mV K^–1 was observed at a P3HT/PS mass ratio of 6:94. At low dopant concentrations (i.e., σ < 10^–5 S cm^–1), the relationship between S and conductivity (σ) followed that of nondegenerate polymer semiconductors (S ∼ σ^–1/4), while at high dopant concentrations (σ > 10^–5 S cm^–1), the S–σ relationship followed that of metals or degenerate semiconductors (S ∼ σ^–1), and cross-over behavior was observed. The giant Seebeck coefficient was ascribed to the unique morphology of the freeze-dried aerogel and the effect of energy filtering. A foam-based energy harvester comprising the P3HT nanofiber aerogel was demonstrated, and a significant induced voltage using a single cell indicated the advantage of P3HT nanofiber aerogels with the giant Seebeck coefficient.

Two fac-rhenium tris-carbonyl complexes bearing a π-accepting pyridoannelated N-heterocyclic carbene (NHC) ligand with general formula Re(CO)₃(pyipy)X, where pyipy is 2-pyridil-imidazo[1,5-a]pyridine-3-ylidene and X = Cl (Re1) and Br (Re2), are investigated as photoredox catalytic systems in light-promoted polymerization reactions. Both rhenium(I) complexes are able to efficiently generate radicals to initiate free radical polymerization. Remarkably, excellent radical polymerization profiles and final conversions are obtained under soft irradiations (LED lamp, λ_exc = 405 nm) by using the proposed complexes with iodonium salt and amine as photoinitiating systems (PISs) for polyethyleneglycol (PEG)-acrylate monomers. The involved mechanism is investigated by means of different spectroscopic techniques and further supported by electrochemical data. In addition, using the prepared three-component PISs, outstanding 3D patterns with spatial resolution could be obtained through direct laser write experiments. Remarkably, the resulting material displays reversible deformation that can be controlled with heating–hydration cycles due to stimuli-responsiveness of PEG chains of the polymeric network, thus opening the way for innovative smart and stimuli-responsive 4D-printed materials and soft actuators.

Functionalized amphiphilic polymers consisting of hydrophilic poly(ethylene glycol) pendant groups and a hydrophobic poly(epichlorohydrin) backbone can spontaneously self-organize into single-chain polymeric nanoparticles (SCPNs) in water, without exhibiting concentration-dependent effects or requiring additional reactive additives or subsequent purification. These SCPNs can effectively encapsulate the anticancer drug doxorubicin and have a high drug-loading capacity, desirable particle size distribution, and excellent drug-entrapment stability in serum-containing media or buffer solutions at various pH values; these unique physical and biological properties will be crucial to the achievement of smart drug delivery nanocarriers based on functional micelles. Cytotoxicity assays confirmed that the drug-loaded SCPNs were not cytotoxic toward normal cells but were significantly cytotoxic toward tumor cells under normal physiological conditions. Our results suggest that the drug-loaded SCPNs exert selective, targeted cytotoxic effects in cancer cells, without affecting healthy cells. Importantly, cellular uptake and flow cytometric assays confirmed that the drug-loaded SCPNs effectively targeted and entered the tumor cells via endocytosis and subsequently effectively promoted apoptotic cell death. Thus, this SCPN system has the ability to improve the overall therapeutic efficacy and safety of cancer chemotherapy.

Ion conduction in nanoscale ion channels or ion pumps to produce electrical signals is the basis of many fundamental biological processes. Inspired by biological ion channels, artificial nanochannels have been extensively explored to mimic the regulation of ion transport in nanochannels and to be applied in salinity gradient power generation. In this study, sulfonated polyether sulfone (SPES) membranes with many nanochannels were constructed via a phase separation method and applied in the salinity gradient power generation field. The nanochannel structure (nanochannel size and length) in the membrane was adjusted by controlling the SPES content and the thickness of the casting solution. These SPES membranes exhibited typical surface charge governing ion transport and excellent cation selectivity. The numerical simulation of ion transport properties for nanochannels with a series of nanochannel sizes and lengths was performed to analyze the effect of the nanochannel structure on the ion transport and salinity gradient power generation properties. The calculated results show that the nanochannels with length and size satisfying a certain relation possess optimal salinity gradient power generation properties. These SPES membranes were also used to generate electricity by mixing artificial seawater (0.5 M NaCl) and river water (0.01 M NaCl). The output power densities of the SPES membranes (M30–10 and M30–50) with the optimized nanochannel structure reached up to 5.8 and 5.6 W m^–2, respectively.

Many sorbents demonstrate exceptionally high absorbance capacity on a per unit mass basis, with some sorbents capable of absorbing hundreds of times their own mass. However, the volumetric capacity (volume of the absorbed liquid per unit volume of the sorbent) remains close to a one-to-one ratio, making transportation and storage of sorbents intended for large volumes of liquid a challenge. A compact volume-expandable sorbent (CVES) has been developed through polymerizing the organic phase of a high internal phase emulsion (HIPE). These polymeric sorbents can transform from a collapsed state (when dry) to an expanded intermediate state (when absorbing a wetting solvent) and to a fully expanded and swollen state (when absorbing a good solvent) and are capable of absorbing a volume of organic liquid more than 20 times the original volume of the sorbent. The CVES demonstrates excellent oil–water selectivity due to a multiscale structure consisting of voids in the porous solid on the order of tens of micrometers and smaller (submicrometer scale) voids within the internal struts as a result of phase separation that occurs during curing of the HIPE. Furthermore, the CVES has a low compression hysteresis loss and retains high oil absorption performance after many cycles of use. Because of these aforementioned properties, the CVES represents a type of high-performance sorbent.