ACS Applied Polymer Materials最新文献

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.

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.

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.

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.

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.

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.

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.

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.