ASAP (As Soon As Publishable)

Carbazole-based conjugated polymers are revolutionizing electrochromic technology and becoming indispensable materials for cutting-edge applications. These polymers showcase exceptional electrochromic capabilities, featuring high coloration efficiency, fast switching times, and outstanding stability, all tailored to their unique structure and doping levels. This review explores the innovative realm of EC conjugated polymers, highlighting the charge transport and photoconductive role of carbazole (Cz) as a main chain building block or subunit, making these materials ideal for use in smart windows, displays, and other optoelectronic devices. The resulting polymers of Cz demonstrate diverse electrochromic behaviors, ranging from transparent to green and blue color transitions, depending on the specific structure and doping level. The presence of carbazole units within the polymer backbone or as side chain substituents allows for further tuning of the material’s properties through chemical modification. Furthermore, our review emphasizes the importance of understanding the relationship between the molecular structures of the polymers and their resulting electrochromic properties. By systematically studying the effects of different substituents, linkage positions, and polymerization techniques, researchers can gain valuable insights into the design principles that govern the performance of these materials. This knowledge is crucial for the development of next-generation electrochromic devices with improved efficiency, durability, and functionality.

Maintaining ultrahigh heat resistance, a low thermal expansion coefficient (CTE), and adequate colorless transparency concurrently poses a significant challenge for colorless polyimides (CPIs), especially as substrate materials for flexible optoelectronic devices. In this work, we designed and synthesized a hydrogen-bonding carbazole tetraphenyl aromatic diamine, 2,7-bis[2-trifluoromethyl-4-aminophenyl]-9H-carbazole (2,7-CPFDA). The corresponding polyimide (PI) films were synthesized via the copolymerization of 2,7-CPFDA and 2,2′-bis(trifluoromethyl)benzidine (TFDB) with 3,3′,4,4′-biphenyltetracarboxylic dianhydride (BPDA) at varying molar ratios. All copolymer PI films presented high heat resistance with the 5% weight loss temperatures (T_d5) between 552 and 563 °C, and the glass transition temperatures (T_g) ranged from 354 to 380 °C. As the content of 2,7-CPFDA increased, the CTE decreased from 17.6 to 10.4 ppm K^–1, while the tensile modulus (E) rose from 5.7 to 6.7 GPa, and the elongation at break (ε) improved from 5.4% to 28%. When BPDA was substituted with 9,10-diphenyl-9,10-bis(trifluoromethyl)-9,10-dihydroanthracene-2,3,6,7-tetraacid dianhydride (6FDPDA) and 4,4′-(hexafluoroisopropylidene)diphthalic anhydride (6FDA), the CPI films exhibited overall favorable properties. Notably, C–PI-7 exhibited a high T_g of 456 °C, excellent mechanical properties (E = 6.7 GPa, ε = 11.9%), low CTE (8.7 ppm K^–1), and high transmittance at 450 nm (T₄₅₀ = 86.1%), thereby meeting the performance requirements for flexible electronic devices.

Polyurethane, as a highly adaptable polymeric precursor, plays a pivotal role in a wide range of advanced applications, particularly in biomedical engineering, regenerative medicine, and multifunctional material design. The Baylis–Hillman reaction synthesized a multifunctional chain extender that provided a suitable platform for postmodification of the polyurethane. Therefore, this study aims to engineer unsaturated hard domains tailored for postsynthetic modifications by designing and synthesizing a novel chain extender through the Baylis–Hillman reaction. The postpolymerization of unsaturated hard domains was accomplished via thiol–ene chemistry as a clickable reaction. This was accomplished by modifying gelatin with γ-thiobutyrolactone, which subsequently served as one of the reactants in the thiol–ene reaction. The influence of the hard segment content on the thiol–ene reaction was systematically investigated to optimize the fabrication of cross-linked gelatinized polyurethane films, highlighting its critical role in controlling the network architecture and mechanical properties. Interestingly, the results demonstrated that the hard segment content plays a pivotal role in governing the formation and extent of cross-linking in the synthesized polyurethane networks. Attenuated total reflection infrared spectroscopy (ATR-FTIR) and nuclear magnetic resonance (NMR) confirmed the successful synthesis of an unsaturated-chain extender and incorporation into the polyurethane backbone. Thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and atomic force microscopy (AFM) were employed to investigate the effect of hard segment content on the formation of cross-linked gelatinized-polyurethane films. Mechanical analysis revealed a direct correlation between the hard segment content and the cross-link density of the synthesized samples. Furthermore, X-ray photoelectron spectroscopy (XPS) confirmed surface composition variations in the polyurethane films upon the incorporation of thiolated gelatin.

Polyureas (PUas) are a versatile class of polymers with wide applications in coatings, flexible electronics, 3D printing, and engineering protection. Herein, a series of thermoplastic PUas with diverse properties were prepared from diisocyanates with different structures and a carbon-dioxide-based oligourea (OUa). First, OUa was synthesized from diamines and carbon dioxide (CO₂); then a group of thermoplastic PUas were fabricated by reacting OUa with diisocyanates. The formation of CO₂-based OUa and its subsequent polymerization with diisocyanates are necessary steps in producing high-performance PUas. The properties of the synthesized PUas depend on the diisocyanate structure. While 4,4′-diphenylmethane diisocyanate (MDI) and CO₂-based OUa produced a tough material with excellent mechanical properties including a tensile strength of 62 MPa, Young’s modulus of 1104 MPa, elongation at break of 209%, and toughness of 85 MJ·m^–3, 1,6-hexamethylene diisocyanate (HDI) and CO₂-based OUa produced an elastic material with a tensile strength of 50.5 MPa, Young’s modulus of 382 MPa, elongation at break of 456%, and toughness of 129 MJ·m^–3. Moreover, PUa derived from HDI and OUa also presented excellent damping properties with an energy absorption efficiency of 94% and an energy dissipation density of 23.0 MJ·m^–3. It could be used as a damping and protective material for wheels, buildings, driveways, etc. It is worth noting that the PUas also exhibited good reprocessing properties, maintaining their mechanical properties after two cycles of reprocessing. Additionally, all the PUas showed good thermal stability, with initial degradation temperature values ranging from 287 to 313 °C.

Polyurethane (PU) has developed rapidly, and it has become an irreplaceable polymer material. Nonisocyanate PUs (NIPUs) have become the focus of research due to the green synthesis route that does not use toxic isocyanates. However, NIPUs face great challenges such as poor mechanical properties, heat resistance, and lack of functions, which greatly limit their applications. In order to enhance the heat resistance and endow functionality of NIPUs, a series of PUs (PCUPs) were synthesized in this paper by melt polycondensation reaction using dimethyl carbonate, 1,6-hexanediol, 1,6-hexanediamine, and nontoxic polydimethylsiloxane (PDMS) as raw materials. The thermal, mechanical properties, water absorption, and anti-graffiti resistance of PCUPs were studied. The experimental results showed that the thermal, mechanical, and graffiti resistance properties of PCUPs were improved by adjusting the content of PDMS. The synthesized PCUPs had excellent mechanical properties with a tensile strength of 38 MPa and an elongation at break of 240% due to the formation of microphase-separated structures promoted by PDMS. After three times of hot compression molding, it still maintains good mechanical properties (87%). In addition, the heat deflection temperature of PCUPs increased from 40.3 to 65.2 °C. Surprisingly, the water contact angle of the PCUP film was 104.7°, showing excellent hydrophobicity and satisfactory graffiti resistance behavior. This study provides a perspective on the functional design of environmentally friendly nonisocyanate polyurethanes.

Transdermal drug delivery (TDD) is emerging as a favorable alternative to traditional oral and injectable drug administration routes, offering a noninvasive, pain-free option with controlled and sustainable drug delivery. However, developing a TDD patch that delivers drugs with a high efficiency while being skin-friendly is still challenging. Here, we report an ultrathin and breathable iontophoretic patch for TDD application. The ultrathin dye-loaded electronic tattoo (UDET) consists of silk nanofibers (SNFs) and graphene. Cationic rhodamine B (RB) and methylene blue (MB) model drugs are incorporated in SNFs. The UDETs can be seamlessly affixed to nonuniform and pliable pigskin. The performance of the iontophoretic system can be fine-tuned by adjusting the applied voltage and duration of the iontophoresis process. The UDET delivers the RB and MB model drugs into pigskin up to a depth of >800 μm under a bias voltage of 20 V within 2 h. Additionally, to evaluate the potential for real-world applications, the diffusion of Dextran molecules of varying molecular weights was examined. The penetration depth of low molecular weight Dextran (Dex-10,000) was significantly higher than that of high molecular weight Dextran (Dex-70,000), demonstrating the influence of molecular size on diffusion efficiency. Our results show the UDET patch’s controllable and efficient delivery capability as well as underscore the potential of UDETs in augmenting TDD through controlled electric fields. This feature would be pivotal for the delivery of therapeutics in scenarios where conventional methods may be inadequate.

Membrane separation technology has garnered significant attention for CO₂ separation and purification, with mixed matrix membranes (MMMs) emerging as promising candidates due to their advantages of ease of processing, high mechanical strength, and thermal stability. The development of effective fillers for separation performance becomes one of the key foci in this area. In this work, CC3, a type of porous organic cages (POCs), was synthesized and functionalized with two amino-containing materials of different chain lengths. Polyethylenimine (PEI) and diethylenetriamine were used as modification agents to successfully graft amino groups onto the CC3 crystals to form defect-free Pebax mixed matrix membranes containing amino-functionalized CC3. The special porous structure of CC3 increases the gas permeability of the mixed matrix membrane by providing extra channels for the transportation of CO₂. Besides, amino groups on functionalized CC3 interact with the chains of Pebax through hydrogen bonding, thus improving the compatibility between filler and matrix. The amino groups can further facilitate the transport of gases across the membrane through reversible reactions with CO₂, which is further enhanced under humid conditions. Under optimal conditions, at 1 bar and 30 °C, the CO₂ permeability of Pebax/PEI@CC3-MMMs was 342.33 Barrer with a selectivity of 33.38, while Pebax/DETA@CC3-MMMs exhibited a CO₂ permeability of 273.34 Barrer and a selectivity of 35.77. This work demonstrates that amino-functionalized POCs (CC3) can effectively enhance the CO₂ permeability and the CO₂/N₂ selectivity, which may provide a way to develop high-performance mixed matrix membranes with superior separation properties.

Leveraging the kinetic selectivity of various thiol-based chemistries, sequential thiol-Michael and thiol–ene reactions were applied semiorthogonally toward holographic recording, thereby expanding the available toolbox for developing thiol–ene-based optical recording media. In a unique ternary mixture, thiol glycolates are highly favored kinetically due to the higher stability and therefore enhanced reactivity of the thiolate anion as compared with aliphatic thiols in the thiol-Michael reaction. The thiol glycolate is base-catalyzed to react with a Michael acceptor, i.e., an electron-deficient double bond, to form the first-stage matrix, leaving most of the aliphatic thiol unreacted and available for the successive thiol–ene photopolymerization. Through product ratios obtained from ¹H NMR, the high kinetic selectivity was demonstrated in small molecule model studies, in which a significant excess loading of aliphatic thiol monomer was utilized (up to five-fold excess of thiol functional groups). Furthermore, the two-stage behavior was evaluated in a bulk material system comprised of multifunctional monomers through photorheology. The resultant films, which are robust elastomers, exhibit high spatiotemporal control in photopatterning. Taking advantage of the decoupled choice of thiol monomers to realize a higher theoretical refractive index contrast between two stages, transmission holographic gratings were recorded in similar formulations, yielding a peak-to-mean refractive index contrast of 0.0064 with high fidelity of spatial resolution even at a size scale of 620 nm period.

Ionic hydrogels and ionogels have been widely utilized as ionic thermoelectric (iTE) materials for converting low-grade heat to usable electricity. However, developing iTE gels that possess environmental tolerance, long-lasting usability, and biofriendliness remains challenging. Herein, we present a highly transparent polymer eutectogel comprising a green eutectic solvent (ES) along with a lithium salt. This eutectogel exhibits a high ionic conductivity of 20.2 mS cm^–1 and an ionic Seebeck coefficient of 9.7 mV K^–1. Thanks to the excellent freeze-resistant property of ES, the ionic conductivity can still reach 7.6 mS cm^–1 even at −20 °C. Additionally, the interaction between the polymer network and ES prevents crystallization within as-prepared eutectogel, instead resulting in a glass transition at −114 °C, slightly lower than a glass transition temperature of ES at −113 °C. Furthermore, as-prepared eutectogel demonstrates exceptional long-term solvent retention, showing no weight loss when exposed to an ambient environment (∼23 °C, ∼60% RH) for 7 days and maintaining 90% of its weight after being placed in an oven for 1 day (50 °C, ∼30% RH with strong air circulation). As-prepared eutectogel also shows excellent stability of TE performance over a wide range of relative humidity. The homemade device utilized as-prepared eutectogel shows the potential to directly power some small electronic devices (such as light-emitting diodes and timers) and to recover wasted heat generated by solar panels. Our results provide a foundation for the development of biofriendly TE gel-like materials that exhibit outstanding environmental tolerance and long-lasting usability.

The observation of auxetic behavior (i.e., negative Poisson’s ratio) in liquid crystal elastomers (LCEs) presents an exciting opportunity to explore application areas previously inaccessible to LCEs. Since its initial discovery, research has focused on improving understanding of the underpinning physics that drives the auxetic response, the structure–property relationships that enable the response to be tuned, and LCE properties such as the refractive index. However, the auxetic LCE materials reported to date have made use of either mechanical strain during fabrication, or unreactive ‘templates’ to stabilize the nematic ordering in the precursors. The latter approach provides excellent monodomain films, but there is unavoidable anisotropic shrinkage of the LCE. Both processes previously employed create complications toward manufacturing and scale-up. In this article, we report the first example of an auxetic LCE synthesized through surface alignment without the use of a nonreactive ‘template’ and thus without the need for a washout. The LCE includes both terminally and laterally attached mesogens, presents an auxetic threshold of 76% strain, and displays a comparable dependence of auxetic behavior on its glass transition temperature as that reported in the literature. This work presents an exciting milestone in the journey toward realizing applications for auxetic LCEs.

Lightweight all-polymer composite foams are fabricated using digital light processing via sequential photopolymerization and thermal activation to expand internal foaming agents, thereby promising alternate routes of manufacturing and installation. However, multistage thermal processing can lead to processing-related defects, restricting the full potential of such foams. To investigate the complex evolution of material properties, we comprehensively characterized their thermomechanical properties during each fabrication stage. Through the heat treatment of fabricated foams, a notable exothermic reaction at elevated temperatures attributed to the thermal curing of residual monomers could be accessed. This postfabrication enhanced material stiffness arises due to a phase transition of the foam matrix from a two-phase polymer-rich/monomer-rich structure to a fully cured single-phase polymer network with no measurable change in foam porosity or void microstructure. We demonstrated that this postfabrication heat hardening could be kinetically controlled to tailor mechanical properties. By advancing our understanding of processing–property relationships, this work offers ways to streamline the manufacturing of precisely engineered composite foams with properties and functionalities that can be introduced on site and on demand.

Composite phase-change thermoregulatory fiber films were successfully fabricated using coaxial electrospinning, with polyacrylonitrile fiber films serving as the sheath and octadecane as the core phase-change material. The optimized phase-change fiber films, produced at a sheath feed rate of 0.60 mL/h and a core feed rate of 0.25 mL/h, exhibited the ability to absorb, store, and release thermal energy within the human comfort temperature range (approximately 28 °C), achieving a high melting enthalpy of 171.6 J/g, indicative of excellent heat storage capacity. Moreover, these fiber films demonstrated outstanding thermal stability, retaining a latent heat of 117.7 J/g after 100 heating–cooling cycles, along with excellent mechanical properties, including a tensile strength of 2.418 MPa, tensile yield stress of 2.331 MPa, tensile strain at break of 36.5%, and an elastic modulus of 58.226 MPa. The films also exhibited an exceptional thermal management performance. This study introduces a promising phase-change material for advanced applications in smart textiles, enabling efficient temperature regulation and energy conservation while ensuring comfort during wear.

With their high safety, high specific capacity, and low economic cost, the environmentally friendly aqueous zinc-ion batteries (AZIBs) are a prospective energy storage technology. However, the challenges faced, such as promiscuous growth of dendrites, water-related corrosion reactions, and weak ion migration ability, significantly affect the development of AZIBs. Herein, poly(vinylidene fluoride) (β-PVDF) with high polarity was used as carrier, and a certain amount of europium chloride was doped to create an artificial solid electrolyte interface (ASEI) layer with hydrophilicity (denoted as PVDF-Eu). The resulting ASEI facilitates the uniform distribution of zinc ions (Zn²⁺), so as to enable uniform Zn deposition. Additionally, the ASEI can effectively suppress the side reactions and improve the cyclic stability of the cells. Consequently, with the effective assistance of the ASEI, the symmetrical Zn//Zn cell can achieve stable plating/stripping for 500 h at a current density of 20 mA cm^–2. The Zn//Cu asymmetrical cell can achieve stable cycles of up to 2250 with an initial Coulombic efficiency of 98.5%. The capacity retention rate of a sodium vanadate based zinc-ion full cell reaches 90.6% after 900 cycles at 10 A g^–1. This ASEI strategy demonstrates a method to enhance the performance of AZIBs.

Materials with circularly polarized luminescence have garnered significant attention due to their applications in anticounterfeiting and displays. In this work, we synthesized a pair of AIEgens, designated as D- and L-TA-TPE, as dopants by utilizing tartaric acid and tetraphenylethylene. These AIEgens were incorporated as dopants into nematic liquid crystal polymer network films. The resulting films exhibited |g_lum| values of about 7.0 × 10^–3, which can be attributed to the chiral conformations of these two AIEgens. For the AIEgen-doped cholesteric liquid crystal polymer network (CLCN) films, due to the selective Bragg reflection of the CLCN films, the |g_lum| values reached about 0.7. When composite films incorporating both fluorescent and CLCN layers were examined, the |g_lum| values reached about 1.6. The |g_lum| value increased with increasing CLCN film thickness. AIEgen-doped CLCN patterns were prepared by using a photomask or through screen printing. Based on the selective Bragg reflection and the handedness of the CPL, distinct images were observed through the left- and right-handed circular polarizers. Therefore, these patterns are potentially applied for decoration and anticounterfeiting.

Conductive polymers have great potential applications as electrode materials for supercapacitors in small energy storage devices. First, manganese sulfate (MnSO₄) was oxidized to manganese dioxide (MnO₂) microspheres with a diameter of 1.5–3.5 μm by catalysis of Ag⁺. Subsequently, polyaniline (PANI) grew in situ on the surface of MnO₂ by the dilute solution method, using MnO₂ as a self-degraded template in an acidic environment. The MnO₂ was gradually reduced to Mn²⁺ because MnO₂ acted as both an oxidant and a template for the polymerization of aniline, resulting in the formation of PANI microspheres with a hollow urchin-like structure. The as-prepared PANI, with its high specific surface area and porous properties, was considered a potential material for surface–interface chemical energy storage. Therefore, the specific capacitance of the hollow urchin-like PANI electrode could reach 531 ± 35 F/g at 5 mV/s, and the loss of specific capacitance was 41.0% when the current density increased from 1 to 10 A/g. Further analysis of the charge storage mechanism of the hollow urchin-like PANI electrode revealed that the electrode was controlled by slow kinetics, indicating that the electrode reaction was mainly controlled by the Faradaic intercalation process inside the active material. A symmetric supercapacitor device was also assembled using hollow urchin-like PANI microsphere electrodes, and the maximum energy density was about 17.92 Wh/kg at a power density of 500 W/kg.

Supersoft elastomers have attracted considerable attention as matrices for flexible electronics, as their moduli closely match those of biological tissues. However, the incorporation of high stretchability, self-healing ability, toughness, and rapid adhesion into supersoft elastomers remains a formidable challenge. We synthesized an elastomer by the one-step photoinitiated copolymerization of commercially available acrylate monomers. The elastomer exhibited strain-reinforcing behavior, and its Young’s modulus was as low as 28.7 kPa. Because of the cooperation of soft and hard phases and hierarchical dynamic interactions, such as dipole–dipole interactions and hydrogen bonds, the elastomer possesses high stretchability (2815% elongation), rapid recovery (3 min), high crack resistance, and self-healing abilities. Notably, the elastomer exhibited rapid (contact time: 3 s), repeatable, and tough adhesion on various substrates in both air and underwater environments. In addition, the elastomer-based sensor detected human motion and handwriting. Overall, this work provides a simple strategy for synthesizing a multifunctional supersoft elastomer, which could be used in supersoft electronic devices.

Irradiation of aqueous solutions containing alkyl chlorides generates peroxyl radicals by reactions of alkyl chlorides, aqueous electrons, and dissolved oxygen. The peroxyl radical can oxidize thioethers to sulfoxides, a transformation that has relevance for targeted or triggered drug delivery. However, small-molecule alkyl chlorides can induce liver damage, which limits their potential for application in anticancer therapy. Here, we show that alkyl chlorides bound to a hydrophilic random copolymer chain behave similar to small-molecule alkyl chlorides. Our work shows that using polymeric alkyl chlorides can be an alternative to small-molecule alkyl chlorides provided that the alkyl chloride functionalities are easily accessible to aqueous electrons.

Functional materials fabricated by using 3D printing are an emerging and cutting-edge research branch in the field of advanced energy, and the mechanical behavior of bimaterial composites is crucial for designing structures with enhanced strength, toughness, and multifunctionality. In this work, the thickness-induced tensile strengthening effect in 3D-printed bimaterial specimens was investigated. Specimens with varying layer thicknesses were fabricated by using a vat photopolymerization (VPP) multimaterial 3D printing process, and tensile tests were conducted to analyze the impact of thickness on the interfacial interaction and overall tensile strength. The experimental results show that reducing the layer thickness of the specimen to 0.2 mm significantly enhances the tensile strength due to improved interfacial bonding and material synergy. The finite element model of the transition region with the equivalent interfacial layer is established based on the microscopic morphology at the interface. Finite element analysis confirmed the experimental results, showing that reducing the layer thickness is beneficial for enhancing tensile strength in bimaterial structures.

Conductive hydrogels are garnering increased attention for their application in flexible strain sensors due to their distinctive inherent excellent properties. However, the high water content leads to inadequate antifreezing capability, severely restricting their application in cold environments. Here, an interpenetrating dual-network hydrogel with intrinsic antifreezing property was prepared by introducing silicone-containing imidazolium ionic liquid [SiM]Cl into an acrylic acid gel system. The introduction of silicone composition increases the fracture strength of the hydrogel by 157% to 0.62 MPa. Notably, the existence of ionic liquid [SiM]Cl greatly enhances the hydrogel’s low-temperature resistance, offering it a freezing point as low as −42.9 °C and a breaking elongation of 650% even at −20 °C. The hydrogel has a conductivity of 2.46 mS/cm and shows excellent linear strain-sensing behavior. Flexible sensors fabricated using this hydrogel demonstrate sensitive and responsive performance to human movements, and the array sensors produced through three-dimensional printing technology can accurately reflect the distribution of force and deformation. Furthermore, the hydrogel exhibits favorable pH sensitivity and inhibits the growth of Escherichia coli and Staphylococcus aureus in more than 99%. The silicone ionic liquid-based multifunctional hydrogel in this work provides a noteworthy strategy for designing low-temperature-resistant flexible strain sensors.

In this work, the synthesis and in-depth characterization of three sets of ultraviolet (UV)-curable diacrylate poly(ethylene glycol) (PEG) monomers containing sulfide/thioether, sulfoxide–sulfone, and methyl sulfonium groups are reported. Three series of solid polymer electrolytes are obtained by photopolymerization of each diacrylate monomer incorporating lithium bis(fluorosulfonyl) imide (LiFSI). The effect of the polymeric nature on the ionic conductivity was investigated. All polymer electrolytes exhibit an electrochemical stability of up to 4 V vs Li⁺/Li. This is extended to 4.3 V vs Li⁺/Li in polymer-containing methyl sulfonium groups, which possess the highest ionic conductivity (2·10^–4 S cm^–1 at 70 °C) and lowest plating–stripping overpotentials (≈0.1 V vs Li⁺/Li). However, polymer electrolytes containing thioether groups show not only high ionic conductivity but also oxidation in sulfoxide/sulfone between 4 and 4.5 V vs Li⁺/Li. The polymer electrolyte containing sulfoxide–sulfone moieties highlights the lowest ionic conductivity and poorest Li interfacial stability. This work provides useful insights into sulfur-containing solid polymer electrolytes for high-performance lithium batteries and energy storage devices.

In this study, we present a hybrid electrolyte design based on single-ion conducting block copolymer-grafted nanoparticles with superior ionic conductivity. By grafting poly(methyl methacrylate) (PMMA) as a neutral core layer on nanoparticles and sequentially polymerizing poly(1-vinylimidazolium-bistriflimide) (PVIm-TFSI) as the charged corona, we achieve well-defined copolymer hybrids with controlled charge gradient and particle dispersion. Three copolymer systems with different PVIm-TFSI chain lengths are analyzed, revealing that longer chains (430 kDa) enhance both particle dispersion and molar conductivity by forming well-connected corona layers, while other shorter chains (170 and 97 kDa) result in sparse strings and aggregated structures, respectively, and they exhibit lower conductivity. Potentiostatic polarization experiments show that the PVIM-TFSI chains rearrange and polarize irreversibly under applied electric fieds and this effect enhances ion conductivity. The polarization response of the copolymer hybrid indicates that PMMA grafts limit the polarization, and the PVIm-TFSI rearrangement in the copolymer occurs at long times. These findings underscore the critical importance of polymer hybrid structures in optimizing ionic conductivity, providing practical insights for applications in electroactive actuators, biomedical devices, wearable sensors, and electrochemical devices, such as capacitors and batteries.

In multicomponent self-assembly, the chemical and compositional diversity of functional molecules governs the formation of complex architectures with distinct functionalities. However, the influence of composition in host–guest systems has rarely been explored. Therefore, this study investigates composition-driven structural modulation in the st-PMMA/C₆₀ complex system. Tuning the encapsulation ratio (E-ratio) of C₆₀ not only regulates the accumulation of C₆₀s molecules within the st-PMMA supramolecular helices but also modulates the composition of the st-PMMA/C₆₀ helical bundles in the semicrystalline morphology. Variations in these hierarchical structures subsequently affect the vapochromism of the st-PMMA/C₆₀ complex. At low E-ratios, isolated C₆₀s molecules within the st-PMMA helices do not trigger a vapochromic response to aromatic volatile organic compounds (VOCs). At a moderate E-ratio of 15 wt %, the st-PMMA/C₆₀ complex forms optimal hierarchical structures, allowing aromatic VOCs to efficiently intercalate into the st-PMMA/C₆₀ helices and perturb the π-conjugation of C₆₀s. However, at the maximum E-ratio, the st-PMMA/C₆₀ complex loses its vapochromic response since the fully occupied supramolecular helices no longer encapsulate aromatic VOCs. Furthermore, the application of electrospinning to fabricate complex fibers increases the surface area, thereby improving the vapochromic response. Thus, this study highlights that hierarchical structures and vapochromic performance can be modulated by tuning the composition of host–guest systems.

Proton exchange membrane fuel cells (PEMFCs) face challenges related to limited lifespan and operational reliability, hindering their commercial adoption. Sulfonated polyether ether ketone (SPEEK) has emerged as a promising alternative to Nafion due to its superior thermal stability, chemical resilience, and cost-effectiveness. SPEEK membranes were sulfonated using concentrated sulfuric acid (98%), introducing sulfonic acid (−SO₃H) groups to enhance proton conductivity. To mitigate chemical degradation while maintaining conductivity, Ce(III)-benzene dicarboxylic acid metal–organic frameworks (Ce-MOFs) were incorporated. These Ce-MOFs scavenge radicals, improving the membrane’s durability and stability. Comprehensive analysis of the physicochemical, thermal, and mechanical properties showed that Ce-MOF addition enhanced conductivity and reduced degradation. The Ce-MOF/SPEEK (1 wt%) nanocomposite membrane achieved 0.215 S/cm at 80 °C and 95% relative humidity, outperforming pristine SPEEK (0.140 S/cm). These findings highlight the potential of Ce-MOF composite PEMs as durable, high-performance materials for next-generation PEMFCs.

Electrospun polyacrylonitrile (PAN) nanofibers are widely recognized as precursors for fabricating carbon nanofibers (CNFs), yet the limited degree of cyclization and frequent fiber breakages during stabilization hinder the mechanical performance of the resulting CNFs. This study introduces a strategy to overcome these challenges by synthesizing poly(acrylonitrile-co-acrylic acid) copolymers with controlled acrylic acid ratios. The incorporation of uniformly distributed carboxyl groups in acrylic acid units within the polymer structure enabled an ionic cyclization pathway, reducing the maximum cyclization temperature to 250 °C and achieving a cyclization degree exceeding 82%. This enhanced stabilization process yielded CNFs with highly graphitized structures with an I_G/I_D ratio of 3.0 and minimal fiber breakages of less than 0.1%. Notably, CNFs derived from P(AN-AA)-5% exhibited a remarkable tensile strength of 28.2 MPa, over three times greater than that of conventional PAN-derived CNFs of 8.8 MPa. This innovative approach highlights the potential of copolymer-based modifications to advance CNF fabrication, offering a pathway for improved mechanical properties and expanded application prospects.

Rechargeable electrochromic Zn-ion batteries (RZEBs) which combine electrochromic properties with energy storage capabilities, represent a promising development in the field of transparent batteries. The aqueous electrolytes are crucial for enhancing the kinetics and capacity of the cathode in RZEBs. However, the Zn anode suffers from hydrogen evolution reaction (HER), dendrite growth, and formation of byproducts due to excess water. Herein, we designed an integrated Janus gel electrolyte by incorporating a propylene carbonate-based organogel with a hydrogel electrolyte. The Janus gel electrolyte not only facilitates efficient Zn insertion in the cathode with short self-coloring time and good cyclic stability but also effectively mitigates water-induced corrosion in the Zn anode. Specifically, the Zn//Cu batteries exhibit a high Coulombic efficiency of 97.91%. Furthermore, the Zn//WO₃ batteries exhibit a specific capacity of 43.64 mA h g^–1 with a capacity retention of 60.84% after 160 cycles. This work provides an effective electrolyte design that significantly enhances the cycle stability of RZEBs.

The use of traditional photosensitive polyimide (PSPI) insulating materials, which possess high coefficients of thermal expansion (CTE) and poor adhesion to copper, easily causes failure issues in the redistribution layers (RDLs). However, there are some trade-offs in the design of the low-CTE PSPI materials such as the ultraviolet (UV) transmittance of the precursors and the dielectric properties of the films. To overcome the above challenges, an AB₂-type fluorinated monoamine (ETFPh-NH₂) with a nonplanar steric structure was designed and synthesized, which was then used as an end-capper attached to poly(amic ester) (PAE) with a linear/stiff structure. The PSPI solutions were then developed by using the as-prepared PAE resins, solvents, and other additives. Despite the presence of ETFPh-NH₂ with a relatively low molar ratio to the total precursor chains, the transparency of the PAE-4 was notably enhanced, resulting in the achievement of the high-resolution lithographic pattern. Meanwhile, the PI-4 film exhibited low-CTE characteristics (23.65 ppm K^–1), and its mechanical and low dielectric properties were enhanced by the microbranched cross-link structure, which was constructed by the reaction of the arylethynyl groups during the imidization process. Furthermore, the adhesion between the PI films and Cu was significantly improved by introducing the aromatic silane (TMS). In short, PI-4, which exhibited high-dimensional stability, strong adhesion with Cu, and photopatternable capabilities, could be a feasible and reliable material for use in advanced packaging. In addition, the developed end-groups modification strategy seems to be an effective way to greatly improve the overall performance of PSPI materials.

Addressing the flammability of epoxy resins and simplifying the production process remain huge challenges. In this work, an imidazole-derived phosphorus/nitrogen-containing latent curing agent (ATIM) was synthesized using nitrilotrimethylene triphosphonic acid (ATMP) and 1-methylimidazole as raw materials for fabricating a single-component flame-retardant epoxy (EP). The ATIM-cured EP (EP/ATIM) showed desired flame-retardant properties, and its UL-94 classification reached V-0 when ATIM content increased to 13 wt %. The limiting oxygen index (LOI) of EP/ATIM-15 (ATIM content: 15 wt %) reached 33.0%, and its peak heat release rate (PHRR) and peak smoke production rate (PSPR) were 51.9 and 41.4% lower than those of the imidazole (IM)-cured EP (EP/IM-7, IM content: 7 wt %), respectively, which demonstrated considerable progress in both flame resistance and smoke reduction properties. EP/ATIM exhibited a higher onset decomposition temperature and greater char residue compared with EP/IM-7, demonstrating superior thermal stability. The shelf life of EP/ATIM-15 could be up to 7 days, confirming that the introduction of P-containing acid endowed EP/ATIM with increased storage stability. Thus, this study offers a feasible strategy for enhancing the storage stability, fire retardant performance, and thermal properties of a single-component epoxy resin.

Phase change materials (PCMs) offer great potential for wearable personal thermotherapy management (PTM) due to superior thermal energy storage and a consistent phase change temperature. Nevertheless, leakage during solid–liquid phase change and the intrinsic solid rigidity of PCMs are long-standing challenges in practical applications. Herein, we report a facile and cost-effective strategy to develop a multifunctional and flexible phase change composite (PCC) consisting of a modified wheat bran (MWB) aerogel and a styrene–isoprene–styrene block copolymer/poly(ethylene glycol) (SIS/PEG) blend. The MWB was first acquired by combining starch gelatinization, chemical cross-linking, conductive reinforcement of a nanofiller (MWCNT/OH), and freeze-drying. Then, the (final) flexible PCC was fabricated through MWB incorporating a phase change dispersion solution (SPEG) that was obtained by blending SIS with PEG. The resultant PCC exhibited excellent leakage-proof properties and good shape stability. The incorporation of SIS enabled MWB/SPEG to maintain superior mechanical flexibility and elastic recovery in both nonphase change and phase change states. The MWB/SPEG displayed high heat enthalpy of melting/crystallization values of 94.9 and 80.8 J/g, respectively. The integration of MWB/SPEG with conductive fabrics achieved residual heat storage/release and maintained the human body’s comfortable temperature in thermotherapy simulation. It provided promising potential in wearable thermal management for this flexible composite.

The preparation of foams with self-healing properties and stable cell structures continues to present significant challenges. In this study, a polydimethylsiloxane elastomer featuring a dual network structure was developed. A dynamic cross-linking network, formed by hydrogen and disulfide bonds, imparted self-healing capabilities to the elastomer. The inclusion of a cross-linking agent created an inherent cross-linking network that improved the mechanical properties and melt strength of the elastomer. The synthesized polydimethylsiloxane elastomer demonstrated an exceptional self-healing performance, achieving a self-healing efficiency of 92.89%, along with impressive mechanical properties, including a tensile strength of 6.32 MPa and an elongation at break of 1277.80%. Additionally, a polydimethylsiloxane elastomer foam with self-healing properties was fabricated using a supercritical carbon dioxide (sc-CO₂) foaming method. With an increase in inherent cross-linking, the cell size decreased from 11.88 to 8.60 μm, while the cell density increased from 2.04 × 10⁹ to 2.71 × 10⁹ cells/cm³, resulting in the uniform cell distribution within the foam. Microcracks in the foam were effectively healed within 10 min at 80 °C, and the cell morphology remained stable after 96 h of exposure to environmental conditions. This dual-network self-healing foam exhibited an excellent self-healing performance along with a stable cell structure.

Although lithium batteries contribute to a green energy economy, most of the materials used in their production are fossil-based. A way to diminish the carbon footprint is by utilizing sustainable and biobased products like lignin, which is highly abundant in nature and vastly produced industrially as a low-value side product in the paper and pulp industry. In the current work, chemically modified Kraft lignins (KL) with different chemical functionalities such as carboxymethyl and sulfomethyl were applied as binder materials for preparing active carbon-based electrodes for lithium metal lab-scale battery cells. The optimization of the lignin binders through functionalization allowed for a significantly enhanced aqueous processability and performance of anodic electrodes composed of hard carbon as the electroactive material and carbon black as the conducting additive. Battery performances were comparable with the state-of-the-art biopolymer binders carboxymethylcellulose (CMC) reaching specific capacity values of 170 mA h g^–1. The functionalization shows an alternative approach to the valorization of lignin in high-tech applications.

In this study, we develop a highly flexible and lightweight electromagnetic interference shielding (EMIS) nanocomposite film based on electrochemically exfoliated graphenes (EEGs), employing a brick-and-mortar structure. A T-shaped conjugated surfactant is synthesized to effectively exfoliate and disperse the aggregated EEGs in the solvent and matrix. The resulting nanocomposite film exhibits well-aligned and tightly bound conductive multilayered nanostructures due to the synergetic interactions of its brick-and-mortar components. The EMIS film, with a thickness of approximately 100 μm, exhibits outstanding mechanical properties, including a tensile strength of 20.7 MPa and Young’s modulus of 1.15 GPa. Notably, it demonstrates exceptional folding reliability by withstanding over 100000 folding/unfolding cycles, which surpasses the performance of previously reported foldable EMIS films. In addition, the well-ordered conductive multilayers composed of the EEGs contribute to the excellent EMIS performance that exceeds 30 dB in the X-band frequency range, effectively blocking more than 99.9% of electromagnetic waves within this range. These results are ascribed to the well-developed supramolecular brick-and-mortar nanostructure, which originates from the synergistic effects of complex interfacial interactions, including π–π, ionic, and hydrogen-bonding interactions. This study also proposes a mechanism that explains the remarkable mechanical properties and significantly enhanced folding reliability of the developed EMIS film.

Natural polyphenols possess inherent defensive properties against pathogens. This study investigated the radical scavenging and antimicrobial activity of biobased polyphenol nanoparticles (PNPs) derived from grape seeds. Scanning electron micrographs and dynamic light scattering confirmed the synthesized nanoparticles’ spherical shape, showing an average hydrodynamic radius of 93.9 ± 4.0 nm. The PNPs exhibited radical scavenging activity at about 433 mg Trolox per gram and a microbial inhibitory effect against Micrococcus luteus and Escherichia coli. The negatively charged PNPs were used to prepare thin multilayer films combined with positively charged polyelectrolytes such as poly(allylamine hydrochloride), poly-l-lysine, poly(diallyldimethylammonium chloride), or polyethylenimine. The viscoelastic properties of polyelectrolyte/PNP films were monitored using a quartz crystal microbalance with dissipation. The PNPs showed the best interface compatibility with poly-l-lysine (PLL), enabling the preparation of mechanically stable thin multilayer films. The antioxidant activity of PLL/PNP films was 72 ± 6 μg Trolox per cm² at pH 10. The PLL/PNP films displayed antimicrobial activity against M. luteus and E. coli, with growth inhibition of 50.7 ± 0.6% and 12.1 ± 0.6%, respectively. The prepared biobased PLL/PNP Layer-by-Layer assemblies can potentially prevent biofilm formation on a large spectrum of materials.

It remains challenging to create rigid fiber networks in hydrophobic silicone rubber (SR) by using hydrophilic cellulose nanofibers (CNFs) with high interfacial compatibility for mechanical reinforcement through solvent-free processing. In this work, a silica-cellulose hybrid nanofiber (Me-SiO₂/CNFs) was prepared via in situ polymerization of hydrophobic silica particles on the CNF surface using the sol–gel method, where CNFs served as a rigid template. The resulting Me-SiO₂/CNFs exhibit a bead-like morphology and can be readily pulverized into the SR matrix, enabling the preparation of highly transparent nanocomposites through conventional mixing and vulcanization processes that eliminate freeze drying and mechanical grinding. With a large specific surface area (221 m²·g^–1) and high aspect ratio, Me-SiO₂/CNFs show strong polymer–filler interactions and form filler percolation networks. In particular, the polymer–filler interactions and energy dissipation capacity are enhanced by the entanglement of SR molecular chains with surface silica particles. Meanwhile, the internal CNF framework establishes a branched fiber network. These two synergistic mechanisms collectively improve the mechanical strength of SR nanocomposites. Notably, the tensile strength and tear strength of SR/CNF nanocomposites increased by 39.7% and 45.5%, respectively. Furthermore, the processability and synergistic reinforcement mechanisms were systematically investigated. This study provides valuable insights for implementing CNFs as a reinforcing filler in industrial applications of high-temperature vulcanized silicone rubber.

Dense polymeric blends with (transiently) fixed positive charges are ideal as anion exchange membranes (AEMs) for treating acidic wastewater with salts via diffusion dialysis. Pyrrolidone from vinylpyrrolidone (VP) copolymers offers a unique chemistry compared to conventional quaternary ammonium, enabling greener and more efficient membrane synthesis. The hydrophobic/hydrophilic characteristics and the miscibility of copolymers with membrane materials determine the microstructure and consequent membrane properties. Here, a commercial copolymer, poly(vinylpyrrolidone-co-vinyl acetate) (P(VP-VAc)), was blended with membrane material polyether sulfone (PES) to prepare PES-P(VP-VAc) blend membranes. The influence of VP content in the copolymers, casting solution composition, and membrane microstructure on the physicochemical properties, mass transfer performance, and stability of the membranes was systematically investigated. It was found that the copolymers (63.8–73.2 wt % VP content, ∼80 kDa) were partially miscible with PES, resulting in microphase-separated membranes. With the VP mass fraction in the blend membranes increased, both the membrane mass increase and volume swelling degree in water and acid increased. When the membrane VP mass fraction reached 41.5 wt %, the permeability coefficients of sulfuric acid and ferrous sulfate increased rapidly. The PES-P(VP-VAc 6/4) blend membrane, containing 41.5 wt % VP, exhibited sulfuric acid and ferrous sulfate permeability coefficients of 228.5 and 4.1 × 10^–9 m²/h, respectively. By simply blending two commercial polymers, this study successfully prepared PES-P(VP-VAc) blend AEMs with a microphase-separated structure, and their application in sulfuric acid recovery through diffusion dialysis was evaluated.

Multidimensional structure warp-knitted spacer fabrics (WKSFs) are integrated with polyurethane elastomers (PUEs) to fabricate shear-resistant reinforced composite materials, demonstrating a 58% enhancement in shear strength compared to pristine PUEs. We quantitatively evaluated the interface thickness and adhesion between WKSFs and PUEs to assess the influence of the physical and chemical properties of the interface on stress conduction and dispersion. The results demonstrate that the stress transfer efficiency and overall reinforcement are highly dependent on the interface quality and the mesh structure of the WKSFs. Finite-element analysis reveals a multidimensional stress dispersion mechanism within the structure, leading to a more effective stress distribution from a theoretical perspective. The findings provide insights into the stress dispersion in different directions of warp-knitted spacer fabric fibers and offer practical guidelines for designing advanced high-performance, energy absorbing, and shear-resistant materials for applications such as protective systems, structural reinforcement, and energy storage.

The integration of additive manufacturing with photoelectrochemical (PEC) systems represents a promising avenue for cost-effective and customizable reactor designs. However, the use of 3D-printed plastic components as optical windows remains underexplored, particularly concerning their transparency, material suitability, and printing parameter optimization. Addressing this gap is crucial to enable fully 3D-printed reactors and windows for applications such as water splitting and light-driven chemical conversions. This work aims to evaluate the feasibility of 3D-printed plastic windows for PEC applications by systematically investigating the impact of printing parameters─such as infill patterns, fill percentage, and layer thickness─on the optical and mechanical properties of three widely used polymers: PLA, PETG, and ABS. A detailed transmittance mapping approach was developed to guide the selection of suitable configurations based on application-specific needs. We fabricated 243 plastic samples and characterized their transmittance in the UV–visible range, correlating the results with printing configurations. PLA emerged as the most transparent material, achieving up to 76.8% transmittance in the visible spectrum. PETG achieved 52% transparency. ABS, on the other hand, was found to be unsuitable due to its opacity, exhibiting <5% transmittance. Proof-of-concept experiments using these plastics as optical windows for PEC water oxidation TiO₂ and BiVO₄ demonstrated that PLA and PETG enabled satisfactory operation, achieving up to 78% and 52% of the performance of standard quartz windows, respectively. Our findings highlight the potential of 3D-printed plastic windows as viable, low-cost alternatives to traditional quartz components, with the added advantage of customization for specific optical and structural requirements. This study paves the way for scalable, sustainable, and tailored PEC reactor designs, opening opportunities in renewable energy and environmental applications.

The development of biobased epoxy vitrimer materials aligns with environmental sustainability. However, constructing fully biobased dynamic cross-linking networks that integrate mechanical, reprocessability, and degradability remains a significant challenge. In this work, a fully biobased epoxy vitrimer with a disulfide bond-decorated dynamic covalent network was developed using biomass-derived diphenolic acid and cystamine. Diphenolic acid underwent an amidation reaction with cystamine, followed by epoxidation to form an epoxy monomer, which was further cured with cystamine to obtain fully biobased epoxy vitrimers. The as-prepared epoxy vitrimers exhibited excellent mechanical properties and thermal stability, attributed to the high cross-linking density and topological interlocking structure induced by amidation. The dynamic cross-linking network endowed the epoxy vitrimers with good self-healing and reprocessability through disulfide bond exchange reactions, while the disulfide bonds could enable degradability when treated with dithiothreitol. When epoxy vitrimers were used as a matrix to form carbon fiber-reinforced composites, the obtained composites exhibited a tensile strength exceeding 613.53 MPa. The resin matrix could be completely degraded in 2.5 h without compromising the structure or properties of the carbon fibers. This work offers insights into the design of fully biobased epoxy vitrimers and their carbon fiber composites.

Epoxy polymers with irreversible cross-link networks are widely used in various fields due to their excellent mechanical, thermal, and electrical insulating performances yet also make them difficult to recycle. Although ester bonds in commonly dielectric insulating epoxy polymers can be activated under certain conditions to endow recyclability, the activation energy of ester bonds is high, and the reprocessability and stability are difficult to balance. The design of epoxy vitrimers with multiple dynamic bonds may achieve excellent recyclability while also possessing high mechanical strength and electrical insulating properties. Herein, epoxy vitrimers with different proportions of disulfide and ester bonds were developed, whose mechanical strength and dynamic thermomechanical and electrical properties were systematically investigated. Results showed that the DDA₂₀ system exhibited excellent comprehensive properties, with a tensile strength of 76.35 MPa, a bending strength of 167 MPa, a glass transition temperature (T_g) of 139.6 °C, an activation energy E_a of 59.9 kJ/mol, a power–frequency (50 Hz) dielectric constant of 4.33 at 30 °C and 5.10 at 105 °C, and a breakdown strength of 31.64 kV/mm, respectively. The recovery rate in mechanical strengths of the DDA₂₀ system reached above 80% at a pressure of 8 MPa, 180 °C for 2 h. This work promotes the application of epoxy vitrimers instead of traditional epoxy resin in electrical equipment.

Cellulose is a plant-based and highly abundant biobased resource and widely used as a filler for polymer composite materials because cellulose fillers have a high aspect ratio and high crystal modulus. Introducing high contents of cellulose fillers into polymer composites reduces the use of petroleum-derived synthetic polymers, increases the mechanical strength, and decreases the toughness due to the aggregation of fillers. In this study, we introduced hydrogen bonds between the polymer matrix and cellulose fillers. Citric acid-modified cellulose (CAC) has many carboxyl groups and forms hydrogen bonds with polymers that have hydroxy groups. The interactions between the polymer matrix and the CAC fillers were evaluated by the glass transition temperature, Fourier transform infrared spectroscopy, and a simulation study based on first-principles calculations. Noncovalent interactions between the polymer matrix and CAC fillers improved the toughness of the CAC composites and enabled mechanical recycling at a high CAC content. This study contributes to the reduced use of petroleum-derived synthetic polymers and longer lifetimes of the materials.

Solid polymer electrolytes (SPEs) are promising candidates for all-solid-state Li-metal batteries (ASSLMBs) due to their high safety and excellent mechanical flexibility. However, the widely used polyethers suffer from low ionic conductivity at ambient temperature and unstable electrode–electrolyte interfaces. In this work, we systematically investigate the reactivities with metallic lithium of three carbonyl-containing polymer-based SPE hosts─a polyketone (POHM), a polyester (PCL), and a polycarbonate (PTeMC)─as potential alternatives to polyethers by means of DFT calculations and AIMD simulations. Our redox potential and frontier orbital analyses indicate that introducing alkoxy oxygens connected to carbonyl groups enhances the electrochemical stability of polyester and polycarbonate, but also increases their reactivity on the Li anode surface. In particular, PTeMC shows higher electron uptake and a lower conduction band when interacting with surface Li. This increased reactivity, however, may also promote the formation of a stable solid electrolyte interphase (SEI), preventing further reduction of the electrolyte. We further summarize the possible decomposition mechanisms of the SPE polymer host and predict the resulting SEI components. The simulations revealed that POHM predominantly undergoes α-dehydrogenation and nucleophilic addition–elimination reactions, while PCL exhibits C_carbonyl–O_alkoxy bond cleavage, producing both saturated and unsaturated lithium alkoxides. In the case of PTeMC, breaking two C_carbonyl–O_alkoxy bonds can generate two saturated lithium alkoxides and a Li_xCO species, or it can produce a RCO₃Li species and unsaturated hydrocarbons via a C_alkoxy–O_alkoxy bond cleavage; these pathways are kinetically favorable and unfavorable, respectively. This work underscores the influence of alkoxy oxygens in carbonyl-containing polymers and provides computational insights for guiding polymer electrolyte design.

Recently, sustainable poly(lipoic acid) (poly(LA))-based biogels have attracted increasing interest and have been used in wearable sensing fields. However, the low stretchability and adhesion, poor self-healing, and wire transmission remain the major issues that limit the applications of poly(LA)-based gel sensors. It is urgent to develop multifunctional biogels with excellent comprehensive performance. In this work, multifunctional conductive poly(LA)-based zwitterionic biogels (denoted as PLLS gels) were fabricated by introducing hydrophilic sulfobetaine methacrylate (SBMA) through nucleophilic addition reactions with poly(LA). The addition of SBMA endowed the gels with conductivity due to the abundant anionic and cationic groups of the zwitterionic structure. The excellent biocompatibility of poly(LA) and SBMA provided the gels nontoxicity and harmlessness. As expected, the PLLS gels possessed high stretchability, adhesion, and self-healing due to the multiple dynamic bonds, including hydrogen bonds and electrostatic interactions. Besides, the gels exhibited excellent biodegradability, antioxidant, and antibacterial activities. The PLLS gels had found application as a wireless wearable sensor, which could monitor various human activities involving temperature changes, human joint movements, and voice recognition. This work not only provides a valuable strategy for constructing the sustainable gel sensors but also expands the applications of biogels to portable mobile monitoring of wireless wearable devices.

This study investigates the preparation of flexible biobased thermosets by cross-linking epoxidized linseed oil (ELO) with three different hardeners: hexamethylene diamine (HMDA), bis(hexamethylene)triamine (BHMT), and sebacic acid. In a comparative analysis of amine and carboxylic acid cross-linkers, the mechanical, thermal, and chemical properties of the resulting thermosets were evaluated using Fourier transform infrared (FT-IR) spectroscopy, differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), thermogravimetric analysis (TGA), and tensile testing. FT-IR spectroscopy revealed the formation of an amide network in samples cured by using amine hardeners. HMDA and BHMT provided superior mechanical properties, with tensile strengths of 3.7 MPa and 2.3 MPa, respectively, compared to 2.0 MPa for sebacic acid. Glass transition temperatures were also higher for HMDA (16.0 °C) and BHMT (12.4 °C) compared with sebacic acid (−1.4 °C). Moreover, TGA showed that samples cured using sebacic acid reached the point of fastest mass loss at lower temperatures (385 °C) than thermosets cured using amine hardeners (450–470 °C), indicating their improved thermal stability. However, HMDA samples exhibited a significant mass loss of up to 40% due to evaporation during curing. This study shows the potential of amine cross-linkers for enhancing performance and underscores the need for further research into optimizing curing conditions and cross-linking chemistry.

Polymer electrolytes (PEs) are at the core of zero-carbon energy storage and conversion technologies, playing a crucial role in the transition to sustainable energy systems. Their appeal also lies in their versatility, enabling customization for diverse applications, from powering microelectronics to enabling large-scale energy generation systems. Herein, we review recent progress in the design and fabrication of PEs, with a special focus on the development of solid, gel, and ionic-liquid-based PEs that enhance the performance of energy storage and conversion devices. The advancement of additives and polymer composites that enhance thermal and electrochemical stability, along with the development of robust cross-linked networks that resist degradation, can address the significant issue of long-term durability in PEs. Innovative fabrication methods for PEs, along with optimized component assembly and design strategies, are essential for maximizing efficiency, ensuring reproducibility, and reducing costs in zero-carbon energy storage and conversion systems.

Skin soft tissue injury represents a prevalent dermatological condition often associated with postsurgical complications such as tissue defects and depressions. In this study, we developed methacrylated konjac glucomannan (KGMMA) through the modification of konjac glucomannan (KGM) with methyl acrylate (MA). The resulting KGMMA was subsequently emulsified and photo-cross-linked to form microspheres for soft tissue augmentation. Optimal preparation conditions were achieved with a 1:3 ratio of liquid paraffin/corn oil in the oil phase and a stirring speed of 800 rpm, yielding KGMMA microspheres with uniform sizes ranging from 100 to 200 μm. These microspheres demonstrated exceptional biocompatibility and showed potential in promoting NIH-3T3 cell proliferation. In vitro experiments revealed that KGMMA microspheres exhibited significant immunostimulatory activity and effectively suppressed TNF-α expression in the M1-type RAW264.7 cells. In vivo studies demonstrated that the microspheres elicited a controlled immune response during the initial phase of subcutaneous implantation and maintained structural integrity without significant degradation over 28 days, suggesting their suitability as a long-term soft tissue filler. These findings collectively indicate that injectable photo-cross-linked KGMMA microspheres possess substantial potential as an effective biomaterial for soft tissue defect restoration.

Amyloid peptides are structurally diverse materials that exhibit different properties depending on their self-assembly. While they are often associated with neurodegenerative diseases, functional amyloids play important roles in nature and exhibit properties with high relevance for biomedical applications, including remarkable strength, mechanical stability, antimicrobial and antioxidant properties, low cytotoxicity, and adhesion to biotic and abiotic surfaces. Challenges in developing amyloid biomaterials include the complexity of peptide chemistry and the practical techniques required for processing amyloids into bulk materials. In this work, two de novo decapeptides with fibrillar and globular morphologies were synthesized, blended with poly(ethylene oxide), and fabricated into composite mats via electrospinning. Notable enhancements in the mechanical properties of the composite mats were observed, attributed to the uniform distribution of the peptide assemblies within the PEO matrix and interactions between the materials. Morphological differences, such as the production of thinner nanofibers, are attributed to the increased conductivity from the zwitterionic nature of the decapeptides. Blend rheology and postprocessing analysis revealed how processing might affect the amyloid aggregation and secondary structure of the peptides. Both decapeptides demonstrated low cytotoxicity and strong antioxidant activity, indicating their potential for safe and effective use as biomaterials. This research lays the foundation for designing amyloid peptides for specific applications by defining the structure–property-processing relationships of the de novo peptide–polymer blends.

The native oxide layer of Ca-metal electrodes impedes Ca-ion transport properties across the electrolyte–electrode interphase. Bis(trifluorosulfonyl)imide-salts (TFSI-) were reported to inhibit any ion transport due to facile degradation at the reactive interface. Poly(ethylene oxide)-based solid polymer electrolytes (SPEs) frequently use Ca(TFSI)₂ for its comparatively high ionic conductivity and hence have not achieved reversible plating/stripping from Ca-electrodes yet. To overcome this roadblock, a Ca-electrode surface treatment with Bi-salt was introduced, enabling operation of Ca/Ca symmetrical cells from a PEO-Ca(TFSI)₂ SPE for the first time. The functionalization greatly reduced interfacial resistances thus allowing reversible Ca plating and stripping from the Ca-SPE.

Porous structures are a common design in the preparation of compressive, flexible strain sensors. It can endow the flexibility and permeability of flexible sensors while effectively increasing the specific surface area and reducing its mass. However, efficient preparation of porous strain sensors with accurate measurement results, high stability, wide operating range, and excellent durability remains challenging. Herein, the salt template method combined with vacuum casting and freeze-drying processes were used to prepare a pristine three-dimensional porous foam model, and a porous lightweight thermoplastic polyurethane (TPU)/carbon nanotube (CNT)@silver nanoparticles (AgNPs) (Vc-TPU/CNT@AgNPs) strain sensor with high compressibility was prepared by impregnating CNTs and growing AgNPs in situ. Thanks to the reduction of AgNPs inside the foam as an interlayer contact point, the resulting microstructure effectively changes the force on the sensor during compression. Meanwhile, the lap of AgNPs as a conductive filler between the layers effectively reduces the overall resistance during foam compression, resulting in a significant increase in sensor sensitivity (gauge factor = 1.40) and giving the sensor a superior linear fit (R² = 0.99875), a wide sensing range (5–70% strain, 88 pa ∼35 kPa pressure), and a rapid response and recovery time (20 ms). The in situ growth of AgNPs and π–π bonding interaction between TPU and CNT then provide excellent durability (500 cycles, 50% strain) for the Vc-TPU/CNT@AgNPs strain sensor. Furthermore, the strain sensors can be successfully used to monitor human motion, ranging from small vibrations in tendons and ears to large strain movements, such as finger flexion and foot stamping. This work provides a proven method for the preparation of porous flexible strain sensors with excellent linearity, good sensitivity, lightness and breathability, and durability, which have promising applications in the field of wearable electronics.

Polyester (PET) has become the focus of research in the shrink film industry due to its good heat resistance, high transparency, and excellent mechanical properties. In order to improve the shrinkage rate of the film, amorphous PET (PETG) is usually obtained by copolymerization modification using some flexible diols and so on. However, introducing flexible structures reduces the glass transition temperature (T_g) and mechanical strength, and importantly, the gas barrier properties of most PETGs are weak. Here, a series of poly(terephthalic acid-naphthalene dicarboxylic acid-ethylene glycol-neopentyl glycol) (PENTN) were prepared by melt polymerization using different contents of 1,4-naphthalene dicarboxylic acid (1,4-NDA) or 2,6-naphthalene dicarboxylic acid (2,6-NDA). The results show that the introduction of 1,4-NDA does not enhance the T_g of the copolyesters significantly, whereas the T_g of the copolyesters increases linearly with the increase in the content of 2,6-NDA. The T_g of 2,6-PENTNs ranges from 82.2 to 90.5 °C. The crystallization is inhibited effectively due to the neopentyl glycol and exhibits good transparency (>85%) and low haze value (<4%), which results in the preparation of copolyesters that are all amorphous polymers. The differences in the effects of 2,6-NDA and 1,4-NDA on the thermal properties of the copolyesters were analyzed. Meanwhile, the copolyesters were prepared into films, and the gas barrier properties were analyzed in detail. The rheological analysis reveals the free volume of the copolyester is rapidly decreasing with the introduction of the naphthalene group structure. The gas barrier property of the copolyesters can be improved to a high level. This work provides an idea for the functionalized modification of packaging materials.

Poly(N-isopropylacrylamide) (PNIPAM)-based hydrogels are widely used in the preparation of Janus actuators due to their remarkable temperature-responsive properties. However, preparing PNIPAM-based hydrogel actuators with excellent mechanical properties, mass transfer ability, and programmable deformation, as well as gaining a profound and systematic understanding of their driving mechanisms, remains a challenge to date. To address these challenges, an efficient PNIPAM-hydroxypropylmethyl cellulose/polyacrylamide-Graphene oxide (PNIPAM-HPMC/PAM-GO) Janus hydrogel actuator with strong interfacial stability was constructed based on the self-generation method; PNIPAM-HPMC was used as the active layer, and PAM-GO was used as the passive layer. The introduction of HPMC makes the active layer have excellent tensile strength (7.55–28.3 kPa) and mass transfer ability (39.07–73.03%), thereby improving the deformation ability of the actuator (239–360°). It can still achieve a 360° deformation after being actuated repeatedly 5 times. The deformation dynamics of the Janus hydrogel actuator under thermal response conditions were quantitatively analyzed by real-time tracking of the response behavior, and the important role of mechanical moduli in the deformation process of the Janus hydrogel actuator was revealed for the first time. Therein, the effect of the elastic modulus difference on the deformation of the actuator is 48 times that of the compression modulus difference. Finally, the Janus hydrogel actuator with high interface stability, mechanical robustness, time-programmable, and double-layer integration prepared in this work shows potential application in the fields of bionics, intelligent switches, and display systems.

Quaternary ammonium iodide (QAI)-containing hydrogels with different alkyl side chain lengths were synthesized and used to develop ionic electroactive strip actuators. The strip bent at relatively low voltages, exhibiting a 5.0 mm bending displacement over the 30 mm strip length at 0.6 V, for example. The bending displacement largely depended on the applied voltages and alkyl side chain lengths. The anticipated bending mechanism is the movement of the iodide anions toward the anode, thereby driving volume contrast in the strip near the anode (volume expansion) and cathode (volume contraction). This mechanism was experimentally confirmed by monitoring the location of the iodide anions in the strip by using scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX) and confocal microscopy. The obtained QAI-containing actuators are operational at relatively low voltages and in water-containing environments and also have antimicrobial properties, which would be useful for biological environment applications.

Covalent organic frameworks (COFs) serve as suitable templates for constructing photocontrol nanozymes due to their highly tunable skeletons and controllable porous channels. Unfortunately, the development of high-performance COFs remains challenging because of their narrow absorption bandwidth, rapid electron–hole separation or recombination, and other limitations. Herein, a polyethylene glycol (PEG) engineering strategy is developed to construct high-efficiency photocontrol oxidase (OXD) mimics based on COFs. A series of COFs with PEG side chains were synthesized through the condensation of an N-containing aldehyde ligand (TPY) with PEGylated amine ligands, which were decorated with PEG chains of different lengths. By introducing PEG chains, the electron–hole recombination of COFs can be slowed down, while electron–hole separation is accelerated; meanwhile, the affinity between COFs and the substrate can be enhanced, thereby improving the photoactive OXD-like activity of COFs. The N atom in TPY induces a red shift in the band-edge absorption of COFs and reduces the band gap, further improving their light absorption performance. Notably, COF-TPY-4O exhibited greater activity than other COFs. As a proof of concept, COF-TPY-4O was used for the construction of biosensors and elimination of bacteria, demonstrating its potential as a photoactive nanozyme with good application prospects. This study highlights the construction of highly active photocontrol nanozymes through PEG engineering.

Polymers that exhibit both a high refractive index and superior transmittance are critically sought for optoelectronic device applications. Polyarylates are considered one of the most promising classes of optical materials for such purposes. Nevertheless, the demand for polyarylates with enhanced refractive indices and elevated light transmission levels is growing. This study introduced a series of innovative polyarylates synthesized via nucleophilic reactions involving bisphenol with a pendant cardo structure and acid chloride derived from a biobased diacid (2,5-thiophenedicarboxylic acid). These polyarylates demonstrated a relatively high refractive index (n_d = 1.695), excellent light transmission (T_400 nm > 86% and T_avg > 92%), and ideal low dispersion (Abbe number = 23). The elevated refractive index can be attributed to the high molar polarizability of thiophene, whereas the exceptional transmittance is credited to the bulky cardo-ring structure that minimizes interactions between polymer chains. Furthermore, these polyarylates displayed excellent thermal properties and solubility, enhancing their processability. This research offers a viable strategy for developing high-refractive-index polymers with excellent transmittance for optical applications.

Although the proportion of binder in batteries is tiny, it plays a significant role in maintaining the integrity of the electrode structure and ensuring the cycling stability of batteries. This study, based on the concept of “redox mediators (RMs),” involved the design and synthesis of a series of Se–Se bonds containing polyurethanes, which have been used as binders for lithium iron phosphate cathodes in lithium-ion batteries (LIBs). Se–Se contained binders as RMs not only accelerate the redox kinetics of the battery but also improve the discharge specific capacity and lithium-ion (Li⁺) transport rate of the battery. The synergistic movement of the hard and soft segments in the polyurethane endowed the binders with high elasticity, and the hydrogen bonding within the binders further enhanced the mechanical properties and reduced the volume change of the electrode during charging and discharging, thus improving the electrochemical cycling performance of the battery. After 500 cycles at 1 C, LIBs with PUPEG-400 as the binders boasted the highest initial discharge specific capacity of 139.77 mA h g^–1, while those with PUPEG-2000 as the binders exhibited the highest capacity retention of 72.37%.

The attractive properties of carbon-fiber-reinforced epoxy resin composite laminate material (CF/EP), such as design flexibility and high specific strength, are mainly utilized in the aerospace industry for applications including aeroplanes, wings, satellite construction, and offshore wind turbines. In recent years, there has been a proliferation of motivational reports concerning the advancement of self-healing technology. However, there is a noticeable dearth of comprehensive reviews that consolidate these cutting-edge developments. As such, this review endeavors to bridge this gap by examining recent preparation methods for CF/EP rooted in the principles of the self-healing theory. Several methods are proposed in the present review for enhancing the healing performance of CF/EP: (1) incorporating reversible bonds and core–shell materials into existing structures to construct a healing resin matrix; (2) developing a healable interface between the carbon fiber and the matrix to prevent inevitable damage caused by the diffusion of microcracks at the interface; (3) creating a healable CF/EP to ensure the healing of microcracks at the CF/EP interlayers by adding healing agents (HAs) such as microcapsules, thermoplastics, hollow fiber, and microvascular; (4) synergistically accomplishing the construction of a hybrid healing system via using two approaches mentioned above. Furthermore, this review also discusses the various properties of healable CF/EP in mechanics and healing efficiency.

Cross-linking agents play a pivotal role in defining the chemical properties of the polyimide (PI) backbone. Even subtle modifications to the backbone chemistry can lead to profound changes in the structure and performance of PI materials. Therefore, selecting cross-linking agents with appropriate structures and properties is critical for tailoring PI materials to meet specific performance requirements. Amino-phenyl polyhedral oligomeric silsesquioxane (POSS) has shown great potential as an effective cross-linking agent for enhancing the performance of PI aerogels. However, systematic investigations into the effects of amino-phenyl POSS cross-linking agents with varying structures and amino group densities on the performance of PI aerogels remain limited. In this study, we synthesized PI aerogels using five different amino-phenyl POSS cross-linking agents. Due to their rigid molecular structures and hybrid organic–inorganic characteristics, the amino-phenyl POSS cross-linked PI aerogels exhibited superior mechanical and dielectric properties compared to PI-TAB aerogels, including a higher compressive modulus (25.17 MPa), lower dielectric constant (1.144 at 10 MHz), and lower dielectric loss (0.0085 at 10 MHz), thereby achieving excellent overall performance. Furthermore, we examined the relationship between the structures and amino group densities of POSS and the resulting properties of PI aerogels. We observed that the size of the POSS cage/ring had minimal influence on the aerogel properties when each phenyl group was connected to a single amino group, as the high cross-linking density mitigated the effect of the POSS cage or ring size. By contrast, larger POSS cages/rings improved the aerogel performance when the amino density was held constant, while lower amino density enhanced performance when the size of the POSS cages/rings was fixed. This study provides valuable insights into the structural–functional design of PI aerogels.

The penetration of moisture and oxygen through the porous carbon electrodes of carbon-based perovskite solar cells (CPSCs) accelerates device degradation, thereby reducing their operational lifespan. To mitigate this issue, polymer encapsulation has emerged as an effective strategy to minimize moisture and oxygen penetration. However, commonly used epoxy-based encapsulants suffer from significant drawbacks, including inadequate toughness and the release of toxic gases during combustion. In this work, we developed an encapsulation process to incorporate eco-friendly and efficient encapsulants derived from cross-linked seminatural polymers into CPSCs. Optically transparent films of the encapsulants were fabricated by infiltrating precursor solutions containing hydroxy-terminated isoprene oligomers (HIO) and 1,6-diazidohexane (DAH) into the CPSC electrodes. The precursors underwent in situ cross-linking via thermal treatment, forming a durable HIO–DAH network both within and on the surface of the electrodes. By optimizing the mole ratios of the precursors, the resulting HIO–DAH film exhibited excellent thermal stability, a smooth surface, and exceptional water resistance. Consequently, CPSCs encapsulated with the HIO–DAH film demonstrated significantly enhanced stability under dark (70% relative humidity and 30 °C) and illuminated (70% relative humidity, 60 °C heating, and prolonged light exposure exceeding 900 h) conditions, compared to unencapsulated CPSCs and those encapsulated with commercial epoxy films. Moreover, the thermal degradation of the HIO–DAH film in an oxygen atmosphere at temperatures between 200 and 600 °C resulted in considerably lower emissions of toxic gases, including carbon monoxide (CO) and carbon dioxide (CO₂), compared to the epoxy films.

Colorimetric lateral flow assays (LFAs) are widely used for detecting analytes through color changes displayed by conjugates on a test strip, typically made of materials such as nitrocellulose (NC) membranes. However, a significant number of conjugate nanoparticles become trapped within the membrane’s porous structure, preventing the full display of color information. Here, gelation of a porous NC membrane is achieved by introducing dimethyl sulfoxide (DMSO) into an LFA strip, resulting in structural changes and high transparency in the NC membrane, exposing red-colored Au nanoparticles within a transparent and portable DMSO/NC membrane. Under optimized conditions (16 μL of 50 vol % DMSO in water and heating the NC strip at 80 °C for 8 min), the membrane becomes highly transparent, achieving 77.42% transmittance while maintaining its capability to effectively perform LFAs for cardiac troponin I (cTnI) in both buffer solutions and clinical samples. We anticipate that this method holds promise for advancing fundamental studies of lateral flow strip materials and has potential applications in healthcare and environmental monitoring.

Hydrogels are water-swollen, three-dimensionally cross-linked polymeric networks widely recognized for their biological compatibility and immense potential across a broad range of applications. However, their inherently poor mechanical properties pose a significant challenge to their widespread practical use. Although numerous strategies have improved the strength and toughness of hydrogels, achieving high stiffness (in the ≥10 MPa range) in addition to these properties remains challenging. The general approach of increasing cross-linking density to enhance stiffness often results in reduced stretchability and toughness, leading to brittle materials. Designing hydrogels that achieve both high stiffness and toughness is fundamentally challenging, as these parameters are often interdependent and conflicting yet essential for practical applications. Recent advancements have enabled the development of ultrastiff hydrogels with elastic modulus exceeding 10 MPa. Remarkably, many of these hydrogels are viscoelastic in nature and also exhibit significant energy dissipation, thereby preserving the toughness. Unlike elastic hydrogels, which rely on spatial design (governed by the polymer architecture), viscoelastic hydrogels also incorporate temporal structures, where cross-linking kinetics (lifetime) significantly affects their mechanical properties. The respective contributions from the spatial and temporal component toward hydrogel performance depends on the hydrogel fabrication strategy. For instance, in semicrystalline hydrogels featuring long chain alkyl domains, the strength of physical cross-links primarily contributes to hydrogel stiffness, whereas enhancing polymer backbone rigidity by incorporating α-methyl groups may increase hydrogel stiffness even when weak cross-links are employed. Some of these aspects, including examples of synergistic combination of different hydrogel network stiffening strategies, are elaborated in this review. This review highlights breakthroughs, examining the fabrication processes, mechanism behind enhanced stiffness, and the trade-offs addressed in these systems. Finally, we highlight promising applications (in the emergent fields of flexible electronics, soft robotics, and biomedical implants) that underscore the immense potential of these advanced hydrogels.

The effective utilization of phase change materials (PCMs) with outstanding thermal conductivity, significant latent heat storage capacity, and exceptional form stability is essential for their functions in thermal energy conversion and storage systems. This work successfully developed form-stable composite phase change materials by combining cellulose nanofibers (CNFs) and biochar (BC) with polyethylene glycol (PEG) into CNF/BC/PEG aerogels using a single-step procedure. The resultant three-dimensional linked porous aerogels proficiently encapsulate PEG, inhibiting leakage by robust surface tension and capillary forces. These CNF/BC/PEG aerogels demonstrate improved thermal reliability, substantial loading capability, and exceptional form stability for the composite PCMs. The differential scanning calorimetry (DSC) investigation indicates that the phase transition enthalpy of these aerogels is notably high, varying from 135.15 to 154.53 J/g. Incorporating BC enhances thermal conductivity of aerogels to 39.5 mW/m·K, with PEG encapsulation achieving 92.6% and thermal storage efficiency at 86%. Furthermore, the composite aerogels exhibit notable thermal regulation properties and efficient thermal conversion and storage, as validated by a thermocouple prototype. These developed composite phase change aerogels have considerable potential for practical thermal storage and management applications.

The ability to distinguish scents, volatile organic compounds (VOCs), and their mixtures is critical in agriculture, food safety, and public health. This study introduces a proof-of-concept approach for VOC and scent distinction, leveraging polymer brush arrays with diverse chemical compositions designed to interact with various VOCs and scents. When VOCs or scents are exposed to the brush array, they produce distinct mass absorption patterns for different polymer brushes, effectively creating “fingerprints”. Scents can be recognized without having to know the absorption of their individual components. This allows for a scent distinction technique, mimicking scent recognition within a mammalian olfactory system. To demonstrate the scent distinction, we synthesized different polymer brushes, zwitterionic, hydrophobic, and hydrophilic, using surface-initiated photoinduced electron transfer-reversible addition–fragmentation chain-transfer polymerization with eosin Y and triethanolamine as catalysts. The polymer brushes were then exposed to vapors of different single-compound VOCs and complex scents consisting of many VOCs, such as the water–ethanol mixture, rosemary oil, lavender oil, and whiskey scents. Quartz crystal microbalance measurements with dissipation monitoring (QCM-D) show a clear difference in brush absorption for these diverse VOC vapors such that distinct fingerprints can be identified. Our proof-of-concept study aims to pave the way for universal electronic nose sensors that distinguish scents by combining mass absorption patterns from polymer brush-coated surfaces.

Polymers backbones with free of aryl-ether structures are preferred for producing stable anion exchange membranes (AEMs) suitable for alkaline fuel cells. In this study, we utilized the inert all-hydrocarbon polymer poly(styrene-b-isobutylene-b-styrene) (SIBS) as the polymer backbone and integrated tertiary amines with varying carbon chain lengths to synthesize alkaline stable comb-shaped AEMs via halogenation and the Menschutkin reaction. The synthesized QSIBS–OH-C_n membranes demonstrated remarkable film-forming capabilities and mechanical properties, and SAXS analysis revealed the presence of distinct hydrophilic and hydrophobic microphase separation structures, which promote the self-assembly of ion clusters, resulting in the formation of interconnected ion transport pathways within the membrane. Therefore, the QSIBS–OH-C_n membranes demonstrated a significant enhancement in hydroxide conductivity, reaching up to 104 mS cm^–1 at 80 °C, a marked improvement over their poly(phenylene oxide)-based equivalents. Furthermore, the QSIBS–OH-C_n membranes exhibited remarkable alkaline stability, maintaining over 92% of their conductivity after 1800 h at 80 °C in a 1 M NaOH solution, underscoring the significance of the polymer backbone and the com-shaped molecular architecture. Finally, the QSISBS–OH-C_n and QPPO–OH-C_n membranes were utilized in single alkaline fuel cells operating with H₂/O₂ at 60 °C, where the QSIBS–OH–C₁₂ membrane demonstrated a peak power density of 537 mW cm^–2 at a current density of 670 mA cm^–2. Moreover, the QSIBS–OH–C₆ and QSIBS–OH–C₁₂ membranes displayed their stability across the durability tests of fuel cell for over 120 h with 0.3 V constant voltage. Overall, this study emphasizes the significance of the SIBS thermoplastic triblock polymer as a backbone and the integration of comb-shaped molecular architectures in developing robust AEMs, offering a strategic method for optimizing the molecular design of AEMs.

This study explores the synthesis of a siloxane-free silicon-based copolymer (PEGDMS) by combining ethylene glycol and bis(chloromethyl)dimethylsilane as monomers. The prepared copolymer was designed to mimic the advantageous properties of poly(dimethylsiloxane) (PDMS) and poly(ethylene glycol) (PEG) while addressing their inherent limitations. The PEGDMS copolymer was characterized by using gel permeation chromatography (GPC), nuclear magnetic resonance (NMR), Fourier-transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). Films based on PEGDMS/TEOS and PEGDMS/Sylgard-184 were then prepared and compared with commercial polymers for several physicochemical properties. These films were further characterized by using FT-IR, TGA, DSC, and X-ray photoelectron spectroscopy (XPS). The PEGDMS copolymer was also employed as a microextraction sorbent for in-tube solid-phase microextraction (IT-SPME) for the preconcentration of a probe mixture of four polycyclic aromatic hydrocarbons (PAHs) before quantification using high-performance liquid chromatography with photodiode array detection (HPLC-PDA). The proposed method demonstrated excellent analytical performance, including low limits of detection (0.95–1.82 ng mL^–1), low limits of quantification (3.2–6 ng mL^–1), a reasonable linear range (0.1–100 mg L^–1), and high coefficients of determination (0.995–0.999). Additionally, the relative standard deviations were consistently below 10% (n = 5).

Polytetrafluoroethylene (PTFE) is the most widely used catalyst layer (CL) binder in a polybenzimidazole phosphoric acid (PBI–PA)-based high-temperature proton exchange membrane fuel cell (HT-PEMFC) due to its great hydrophobicity. However, PTFE also limits the formation of an effective triple-phase boundary (TPB) due to its strong resistance to acid retention. To obtain the composite ionomer in the CL of HT-PEMFC, polybenzimidazole (PBI) is thus invited. Then, an in situ quaternization strategy on PBI is developed to increase the TPB concentration in CL by controlling the PA distribution and taking into account the superior PA retention capability of quaternary ammonium groups. At the same time, Pt active sites can be freed and mass transfer channels can be in situ constructed. Consequently, the corresponding HT-PEMFC fed with H₂/O₂ attains a maximum power density of 755 mW/cm² and an electrochemical surface area of 35.56 cm²/mg_Pt, surpassing those equipped with PTFE by 10 and 30%, respectively. The electrochemical performance improvement indicates that the in-situ quaternization strategy on the ionomer has great application potential in practical HT-PEMFC manufacturing.

The pursuit of protective materials that strike a perfect balance between flexibility and superior impact resistance continues to drive significant advancements in material science, despite the inherent limitations of conventional materials. This study introduces a class of supramolecular poly(urethane-urea) elastomers, carefully designed by combining polycaprolactone soft segments with hydrogen bond-rich hard segments. This unique composition not only provides exceptional quasi-static mechanical properties, ensuring durability under everyday use, but also excels in dynamic mechanical properties essential for protection against high-speed impacts. These elastomers exhibit outstanding tensile strength, toughness, and impact resistance, outperforming existing commercial materials. Their remarkable performance is attributed to a supramolecular network structure with strong interactions between the soft and hard segments, which efficiently redistribute and dissipate energy through deformation and dynamic hardening. Furthermore, the reversible hydrogen bonds within the polymer matrix enhance the self-healing capabilities and recyclability of these materials, offering a sustainable solution for high-performance protective gear.

The implementation of energy-dense lithium metal anodes in lithium batteries requires an electrolyte material that enables rapid and selective cation motion and low anion mobility. Although single-ion-conducting polymer electrolytes are selective, they typically exhibit conductivity values several orders of magnitude lower than liquid and neutral polymer electrolytes. In this report, we investigate the effects of blending single-ion-conducting polymer electrolytes (i.e., metal salts with a macromolecular polyfunctional anion) with neutral polymer hosts on the conductivity and ionic motion. With the goal of improving ionic conductivity without overly mobilizing anions, two comb-branched copolymers, with high and low ion-content poly[(lithium 3-[(trifluoromethane) sulfonamidosulfonyl]propyl methacrylate)-co-(poly(ethylene glycol methyl ether acrylate))], were blended with either poly[(ethylene oxide)-co-(allyl glycidyl ether)] or poly(cyanoethyl glycidyl ether) at various polyelectrolyte loadings. These blends are miscible over a wide range of compositions and increase the conductivity of the single-ion-conducting polyelectrolyte by up to 2 orders of magnitude. Neither the glass-transition temperature nor dielectric constant correlates strongly to conductivity in these systems. Instead, the overall Li:O ratio of the blend influences conductivity and exhibits an maximum at ca. 0.05. Finally, we investigated ion mobility through limiting current fraction of Li⁺ ions and observed fractions up to 0.92 with ca. 0.75 for the most conductive blends.

Passive radiative cooling (PRC) and solar heating (SH) are highly desired in a variety of areas such as personal thermal regulation and thermal control of a building’s macroenvironment. However, most current thermal management materials are usually a single function with static temperature regulation, resulting in a poor feature with environment adaption. Here, a phase-change material-integrated dual-mode Janus film with enhanced radiative cooling and SH for thermal management is demonstrated. The Janus film is developed by integrating a paraffin-type phase-change material (PCM) and carbon nanotube (CNT)-modified poly(dimethylsiloxane) (PDMS), enabling both PRC and SH. The cooling mode of Janus film is achieved by infrared ray thermal radiation of PDMS and absorbing heat of PCM. The heating mode of Janus film is achieved by SH of the CNTs@PDMS layer, and solar energy is converted into heat energy stored and released by PCM@PDMS. The introduction of PCM enhances the practical effects of radiation cooling and SH. The energy storage of PCM can be released at night, avoiding unwanted overcooling. In addition, the PCM@PDMS features self-cleaning and self-repair abilities. This work provides a PCM-enhanced dual-mode thermal management strategy toward applications in a practical scenario with dynamic ambient temperature variations.

This study introduces the fabrication of dual-layer composite nanofiber membranes incorporating AG80 (tetrafunctional epoxy resin), BN (boron nitride), and PI (polyimide) through electrospinning, with the aim of overcoming the limitations of conventional polyimide (PI) materials in thermal management and electrical insulation for flexible circuit boards. Although PI is recognized for its mechanical strength, chemical stability, and insulating properties, its low thermal conductivity, brittleness, and complex processing challenges limit its broader application. By precisely controlling the composition of AG80, BN, and PI, and optimizing electrospinning parameters, we successfully developed a nanofiber membrane that exhibits enhanced thermal stability and insulation properties. The resultant membrane demonstrates remarkable flexibility, retaining mechanical integrity after 10,000 bending cycles, and achieves a high thermal conductivity of 1.42 W/m·K. Optimized porosity further enhances surface adhesion, rendering it ideal for high-performance flexible circuit boards. These findings provide valuable theoretical and practical insights for the design and development of advanced flexible electronic devices.

Magnesium and lithium exhibit similar behaviors in aqueous solutions, making their separation from each other in saltlake brine challenging. Here, we report the design and synthesis of four lithium carboxylate-based covalent organic frameworks (COFs), ATSA-1 through ATSA-4, that selectively adsorb Mg²⁺ ions over Li⁺. Adsorption performance was investigated under varying initial Mg²⁺ concentrations, adsorbent dosages, and contact times. Among the COFs, ATSA-4 demonstrated the highest Mg²⁺ adsorption capacity, reaching 19 mg g^–1. Adsorption data aligned with the Langmuir isotherm model, while kinetic analysis indicated a pseudo-second-order model best described Mg²⁺ uptake. Regeneration tests revealed that hydrochloric acid at pH 3 efficiently desorbed Mg²⁺, enabling the COF reusability. Additionally, a COF-supported ultrafiltration bed yielded a Mg²⁺ separation flux of 19 g h^–1 m^–2. The ATSA-COF series further displayed a high selectivity for Mg²⁺ in mixed Mg²⁺/Li⁺ solutions.

A mussel-inspired mechanism was used to solve the problem of filler aggregation in rubber composites. This research aims to improve carbon black (CB) dispersion in epoxidized natural rubber (ENR) composites through π–π stacking and cation−π interactions by adding dopamine (D). In this study, various aromatic interactions (π–π stacking and cation−π interactions) between the D-functionalized ENR molecules and the surface of the CB were observed by Fourier transform infrared (FTIR) and Raman spectroscopy. Notably, the small and wide-angle X-ray scattering (SAXS/WAXS) analyses supported our inference from the rubber processing analysis (RPA) and transmission electron microscopy (TEM) results that the aromatic interactions enhanced the CB dispersion in ENR composites. This phenomenon improved the tensile strength (138%), Young’s modulus (93%), and energy-saving properties (50%). Finally, this research provided an alternative strategy using mussel-inspired material to solve the CB aggregation problem in rubber products, yielding ENR composites with superior performance properties.