ACS Applied Polymer Materials最新文献

Neohesperidin (NHP), a flavanone compound widely distributed in citrus peels and traditional Chinese medicinal materials, such as immature and mature bitter orange (Aurantii fructus immaturus and Aurantii fructus), exhibits various pharmacological activities, including antioxidant, anti-inflammatory, and neuroprotective effects. The large quantity of peel waste generated as a byproduct of citrus processing is rich in NHP, representing an important source of this compound and highlighting the importance of its high-value utilization. However, conventional extraction methods suffer from low efficiency and significant solvent-related pollution. Therefore, the development of adsorbents featuring high efficiency, good reusability, and strong specificity toward NHP is of great significance. In this study, a neural network model was constructed for the first time to predict suitable functional monomers for molecularly imprinted polymers (MIPs). Based on the prediction results, NHP molecularly imprinted polymers (NHP/MIPs) were successfully synthesized. The experimental results demonstrated that the prepared NHP/MIPs exhibited high specificity and adsorption capacity for NHP, with an adsorption capacity of 35.58 mg/g and an imprinting factor (IF) of 1.89. After six adsorption–desorption cycles, the material maintained excellent regeneration stability, achieving a recovery rate of 74.62% to 77.99% for NHP in spiked samples. The neural-network-assisted functional monomer screening strategy proposed in this study significantly enhances the synthesis efficiency and molecular recognition specificity of MIPs, providing an approach for the selective enrichment of target molecules in complex samples. This research offers a promising adsorbent for the selective enrichment of NHP from citrus fruits and complex matrices.

Artificial enzymes that marry synthetic simplicity with enzyme-like function remain elusive. We report water-soluble acrylamide random copolymers obtained by aqueous free-radical copolymerization of poly(ethylene glycol) methyl ether methacrylate (PEGMA, M_n ≈ 500) with acryloyl-l-amino acids (histidine, serine, arginine, aspartic acid; 30–50 mol %). In water, these polymers self-assemble into catalytic polymeric nanoparticles, as visualized by transmission electron microscope (TEM). ¹H nuclear magnetic resonance spectroscopy (NMR) and Fourier transform infrared spectroscopy (FTIR) confirm amino-acid incorporation; TEM reveals dynamic reorganization and fusion-driven growth, indicative of dynamic micellar-like assembly behavior. The nanoparticles catalyze both (i) the direct aldol of cyclohexanone with p-nitrobenzaldehyde and (ii) hydrolysis of p-nitrophenyl benzoate (PNB). Aldol conversions are quantitative under basic conditions but enantioselectivity remains modest (syn/anti ≈ 1:2–1:3; ee up to 17.8% with Zn²⁺), reflecting flexible, weakly organized chiral environments within the dynamic aggregates. In PNB hydrolysis, histidine/serine increase k_cat (3–4 h^–1) relative to arginine (∼0.5 h^–1), while Zn²⁺ coordination modestly improves efficiency, indicating metal-residue cooperativity. These results establish a minimalist route to aqueous nanozymes and delineate how residue identity, polymer self-assembly, and Zn²⁺ coordination govern reactivity and selectivity in polymeric catalysts.

Conductive hydrogels have demonstrated significant potential in flexible electronics due to their adjustable flexibility and remarkable sensitivity. However, the development of flexible wearable electronic devices may be impeded by the time-consuming and energy-consuming polymerization process of hydrogels. In this study, a sodium lignosulfonate-Al³⁺ (LS-Al³⁺) self-catalytic system was designed to efficiently decompose ammonium persulfate (APS) at 25 °C within 9 min, initiating rapid polymerization of acrylic acid (AA) monomers. Benefiting from strong physical and chemical cross-linking, the hydrogel demonstrates excellent mechanical properties (elongation: 1753%; tensile stress: 0.139 MPa). Furthermore, the prepared hydrogel exhibits UV-blocking ability, antibacterial activity, freezing tolerance, high ionic conductivity (0.648 S/m) sensitivity along with near real-time response (252 ms) and notable thermosensitive behavior. When applied as flexible strain sensors, they can accurately real-time and accurate monitoring of both large-scale and subtle human motions. These features highlight its promising potential for wearable strain-sensing applications. The strategy proposed here pave the way for efficient and eco-friendly preparation of advanced hydrogel materials.

Photonic microcapsules with dual stopbands hold great potential in sensing and wearable electronics. However, existing systems face limited deformability and responsiveness to physical stimuli. In this study, we fabricated fully deformable dual-stopband photonic microcapsules using microfluidics-enabled core–shell double-emulsion templates. The core and shell parts of the microcapsules were an aqueous suspension of PNIPAM-co-AAC hydrogel particles and a poly(ethylene glycol) phenyl ether acrylate (PEGPEA) resin suspension of silica particles, respectively. Given that the core and shell parts were both deformable components, the resultant photonic microcapsules featured full deformability. Their structural colors can be regulated by tuning the particles’ diameters and volume fractions. The resultant microcapsules exhibited isotropic reflection spectra, overcoming angle dependence, and showed reversible color changes under mechanical compression. This work offers a scalable approach for multifunctional photonic microcapsules, paving the way for applications in microsensors, stress visualization, and adaptive wearable devices.

Synthetic polycations are key components for engineering polyelectrolyte complexes with wide-ranging biomedical potential. However, the high cytotoxicity of fully charged polycations remains a major limitation for clinical applications. To address this challenge, we report on polycations derived from the cationic monomer 2-(N,N-dimethylaminoethyl) acrylate (DMAEA), which gradually loses charge through hydrolysis, thereby reducing their charge density over time. The overall charge fraction (from 100% to 20%) was further controlled through copolymerization with the neutral comonomer 2-hydroxyethyl acrylate (HEA). The selected conditions of reversible addition–fragmentation chain transfer (RAFT) copolymerization, specifically protonation of DMAEA with trifluoroacetic acid to mask its tertiary amino groups, enabled a precise control over the characteristics of the copolymers (termed D/H) up to 75% conversions, with close agreement between theoretical and experimental molecular weights up to 100 000 g/mol, consistently low dispersities (<1.2), and an excellent match between the theoretical and actual copolymer compositions. Hydrolysis studies at pH 7.4 showed that increasing the HEA content in D/H copolymers from 20 to 50 mol % led to only a 10% increase in the hydrolysis over 3 weeks. Isothermal titration calorimetry analysis demonstrated that all copolymers retained their ability to complex with heparin, with binding strength comparable to that of commonly used polycations. Importantly, the cytotoxicity of D/H copolymers toward human umbilical vein endothelial cells (HUVECs) decreased with increasing HEA content, reaching more than 80% cell viability at a relatively high concentration of 30 μg/mL. These findings demonstrate that D/H copolymers combine precise structural control with reduced cytotoxicity, making them promising candidates for biomedical polyelectrolyte platforms.

Conductive elastomers have attracted considerable attention because they can mimic the tactile sensation of human skin while possessing mechanical properties comparable to those of skin. When used as skin sensors, these materials inevitably suffer damage, highlighting the importance of their self-healing capabilities. Moreover, the energy dissipation mechanism of conductive elastomers under stress remains unclear. To address this issue, we developed a conductive elastomer based on polymerizable low-melting-point solvents combined with tannic acid (TA) to reinforce the hydrogen-bonded framework. This design endows the aqueous conductive elastomer with both excellent self-healing performance and enhanced mechanical properties, as demonstrated by its fracture stress of 1.5 MPa, fracture strain of 815%, and capability to recover over 76.7% of its original mechanical strength after 24 h of room-temperature self-healing. As a strain sensor, it exhibits high sensitivity (GF ≈ 11.51), rapid response time, and outstanding sensing stability. Boasting these excellent properties, the conductive elastomer is promising for sustainable electronic skin applications. Molecular dynamics simulations and finite-element analysis confirm that the 30 wt % TA-derived dynamic hydrogen-bond network facilitates surface segment interdiffusion, energy dissipation, and stress concentration suppression, improves ductility, and breaks the traditional performance trade-offs.

Aromatic polymers have gathered much interest as promising candidates for membranes in fuel cell applications due to providing multiple sites for electrophilic substitution with the SO₃H group. However, free radical attacks during proton exchange membrane fuel cell operation primarily cause degradation, reducing proton conductivity. To mitigate these challenges, we prepared phosphoric acid (PA)-incorporated triazine-triamine-based diphenyl diacetol (TT-DPDA) polymers with graphene oxide (GO) functionalization and utilized as a membrane for fuel cell applications. The resulting electrolyte nanocomposite membrane, comprised of functionalized GO nanosheets integrated into the PA/TT-DPDA (GO@PA/TT-DPDA) polymer matrix exhibited a marked increase in the proton conductivity. Notably, the membrane containing 3% GO demonstrated an impressive ion exchange capacity of 1.27 mol^–1 g^–1 and a proton conductivity of 11 × 10^–2 S/cm at 120 °C. Analysis of the proton transport mechanisms within the membrane, based on Arrhenius plots for proton conductivity, indicated that both Grotthuss and vehicular mechanisms contribute to effective proton conduction. Furthermore, the 3% GO-dispersed PA/TT-DPDA polymer nanocomposite membrane exhibited a remarkable oxidative stability, registering a value of 50.2% in Fenton solution at 80 °C over 24 h. The mechanical properties of both the PA/TT-DPDA polymer and its GO-enhanced counterpart were rigorously evaluated, highlighting the potential of these membranes for applications in fuel cell technologies.

Ferroelectric polymers exhibit enormous potential in dielectric capacitors due to unique electrical properties, such as high dielectric constant and ferroelectricity. However, their poor insulation performance and high dielectric loss lead to energy storage properties that are insufficient for practical applications. In this article, a synergistic strategy of carrier transport suppression and electric field distribution regulation is proposed to enhance their energy storage performance. Specifically, by introducing Bis-PCBM, an organic molecular semiconductor with high electron affinity, into highly polar poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) (PVTC), deep traps are constructed to inhibit carrier transport. Furthermore, three-layer composite films of P-0.9M/PET/P-0.9M (PTP) and PET/P-0.9M/PET (TPT) are fabricated by using high-insulation polyethylene terephthalate (PET). Finite element simulation reveals that the redistribution of the electric field in the trilayer films is achieved based on the difference in dielectric constants of the polymers, enabling the insulating layers to withstand higher electric fields and the polar layers to operate in a high-efficiency range. Especially at high temperatures, the marked increase in the dielectric constants of PVTC shifts the electric field distribution with the consequence that the polar layers bear a lower share of the overall electric field. This temperature-adaptive self-regulation behavior of the electric field distribution significantly reduces the failure probability and enhances the energy storage performance. At 25 °C, the breakdown field strength (E_b) of TPT reaches 578.8 MV/m, with an energy storage density (U_e) of 8.18 J/cm³ and a charge–discharge efficiency (η) of 72.33%, which are 56.4, 50.6, and 71.8% higher than those of PVTC, respectively. Notably, even at 100 °C, TPT maintains a breakdown strength of 456.8 MV/m, an U_e of 4.22 J/cm³, and a η of 49.70%, achieving significant improvements (44.4, 104.9, and 208.5%) compared with P-0.9M. This work provides a simple, effective, and field-adaptive strategy for enhancing both the insulation and energy storage performance of ferroelectric polymers.

The widespread occurrence of pharmaceutical residues in aquatic environments demands robust, reusable, and solar-activated photocatalytic materials that are capable of operating under mild conditions. In this work, we developed biobased Starch/PVA thin films incorporating meso-tetra(phenyl)porphyrin (TPP) and its Zn(II) complex (ZnTPP) as heterogeneous photocatalysts for the degradation of nonsteroidal anti-inflammatory drugs acetylsalicylic acid (ASA) and ibuprofen (IBU). The porphyrins were immobilized in situ within a citric acid cross-linked Starch/PVA network, yielding hybrid materials with well-defined structural, thermal, and photophysical properties. Comprehensive spectroscopic, thermal, and morphological analyses confirmed the successful incorporation of the porphyrins and revealed distinct polymer–porphyrin interactions, with ZnTPP promoting higher surface roughness and enhanced accessibility to catalytic domains. Under visible-light irradiation, the Starch/PVA/ZnTPP films exhibited markedly superior photocatalytic activity, achieving up to 93% removal of pharmaceuticals under optimized conditions. Mechanistic studies employing EPR spectroscopy and radical scavengers demonstrated that superoxide radical anion (O₂^•–) is the predominant reactive oxygen species driving degradation, while swelling, spectroscopic, and topographical analyses correlated catalyst performance with polymer-network hydration and the porphyrin microenvironment. Photocatalytic efficiency was strongly influenced by operational parameters, with optimal activity at neutral pH, intermediate pollutant concentrations, and low catalyst mass. Importantly, the films displayed exceptional operational stability, maintaining their photocatalytic performance over at least 15 consecutive reuse cycles under both artificial white-light and natural sunlight irradiation. Together, these results position the Starch/PVA/ZnTPP films as a promising, low-cost, and environmentally compatible platform for the visible-light-driven degradation of pharmaceutical contaminants. The combination of renewable polymer matrices, tailored photophysical behavior, and outstanding reusability underscores the potential of this hybrid material as a practical and scalable technology for sustainable water remediation.

The long-term performance of organic electronic materials hinges on their ability to maintain structural and electronic order under environmental and device stressors. However, once morphological disorder sets in through oxidative degradation, photobleaching, or thermal cycling, recovery has traditionally been considered irreversible. Here, we present a postdegradation recovery strategy for organic semiconducting thin films using a nonchemical, noninvasive external electric field (EEF) treatment. By coupling an EEF stimulus with solvent vapor-induced softening, we induce significant nanoscale morphological reorganization, enabling the recovery of degraded crystallite orientation and promoting favorable H-aggregate formation. Grazing-incidence wide-angle X-ray scattering (GIWAXS) reveals that EEF treatment not only restores lamellar and π–π stacking but enhances edge-on crystallite alignment beyond that of pristine films. Concurrent absorption spectroscopy studies show vibronic peak shifts and intensity ratios indicative of a preferential transition toward H-aggregated domains, reflecting enhanced intermolecular interactions and more favorable charge transport pathways. Quantitative analysis via mosaicity factor (MF) mapping further confirms a narrowing of the crystallite orientation across dominant diffraction axes. This EEF-driven recovery process demonstrates a nonchemical route to reverse degradation-induced disorder and achieve postfabrication control over polymer morphology without the need for additives, thermal annealing, or irreversible chemical modifications, with broad implications for extending device lifetimes and improving the reliability of flexible organic optoelectronic technologies.