ACS Applied Polymer Materials最新文献

Monodisperse polymeric microspheres (uniform spherical aggregates of polymer chains with micrometer-scale dimensions) hold great promise for applications spanning materials science, biotechnology, and diagnostics. Yet, achieving simultaneous control over polymer chain growth and microsphere formation remains a formidable challenge. Here, we report a high-temperature photoinitiated reversible addition–fragmentation chain transfer (RAFT) dispersion polymerization that employs a poly(ethylene glycol)-based macro-RAFT agent to direct microsphere formation and a small-molecule RAFT agent to mediate polymer chain growth within the particles. This dual-RAFT strategy enables the synthesis of polymeric microspheres with narrow size distributions and well-defined polymers of tunable molecular weights, while the stabilizer loading can be as little as 0.1 wt %. Both polymer chain and particle growth can be temporally modulated by light on/off switching. The resulting polymers retain high end-group fidelity, allowing efficient one-pot synthesis of well-defined (multi)block copolymers with low dispersities while maintaining particle size uniformity. Furthermore, this approach provides access to nanostructured block copolymer microspheres with uniform sizes and well-defined internal morphologies, an achievement that remains elusive by conventional methods.

A range of photo-cross-linkable poly(aryl ether) copolymers with high-density quaternary ammonium groups were synthesized. Then, the anion exchange membranes (AEMs) were fabricated through quaternization and alkalization of the copolymers, with subsequent photo-cross-linking under UV irradiation while in hydration state at room temperature. The photosensitivity, thermal stability, and surface morphology of the membranes were evaluated through UV–vis spectrum, thermogravimetric analysis (TGA), field emission scanning electron microscopy (FE-SEM), and high-resolution transmission electron microscopy (HR-TEM), respectively. The membrane properties were evaluated based on mechanical properties, ion exchange capacity (IEC), water uptake, water swelling ratio, ionic conductivity, methanol permeability, and alkaline stability. The tensile strength of membranes ranged from 19.5 to 25.6 MPa, and the photo-cross-linking significantly enhanced the tensile strength of the membranes. The IEC values of the cross-linked membranes were varied between 1.48 and 2.08 mmol g^–1 at 20 °C. The water uptake and swelling ratio of cQPPAE-x-y were varied from 4.96% to 75.36% and 0.75% to 19.31% at 20 °C, respectively. The hydroxide conductivity of the cross-linked membranes ranged from 11.57 to 29.56 mS cm^–1 at 20 °C, reaching a peak of 167.50 mS cm^–1 at 80 °C. Additionally, the copolymer membranes demonstrated outstanding methanol resistance, with a methanol permeability of 1.573 × 10^–7 cm² s^–1 at room temperature, markedly reduced compared to Nafion 117 (23.8 × 10^–7 cm² s^–1) by a factor of 15. Notably, the cross-linked membranes retained high ionic conductivity while achieving enhanced dimensional and alkaline stability.

Cellulose nanocrystal (CNC) photonic composites exhibit vivid structural colors but suffer from an inherent brittleness. Here, we develop flexible photonic CNC nanocomposites through in situ hybridization of periodate-oxidized dialdehyde CNCs (DACNCs) that maintain the original structural color (λ = 447 nm) while enhancing mechanical properties. The key innovation lies in DACNC’s dual functionality: it integrates into the chiral nematic helical structure while remaining optically neutral, participating in the formation of the nanocomposite film without altering the structural color. Circular dichroism confirms the preserved left-handed chiral character, and polarized optical microscopy reveals maintained birefringent textures. With 20% DACNC loading, the composite achieves a more than 4.3-fold fracture strain increase (5.1% versus CNC’s 1.2%), a 2.9-fold tensile strength (from 18.4 to 53.0 MPa) increase, and an 18-fold toughness increase (0.09 to 1.68 MJ/m³) without compromising the photonic property. This unique compatibility enables efficient stress dissipation while perfectly conserving the photonic nanostructure. Our work establishes a novelty materials design paradigm in which mechanical reinforcement and structural color integrity are simultaneously achieved through functionally differentiated components.

Poly(vinyl alcohol) (PVA) is an ideal substrate for electronic skin (e-skin). However, the interface mismatch between conductive materials and the skeleton as well as the monotonicity of the conductive network still hinders its creation. Herein, a high-performance PVA-based hydrogel e-skin with dual-mode conduction of NaCl and highly conductive PPy-modified pulp fiber is accomplished by loading the hydrogel skeleton via “freezing-thawing and salting-out”. The resulting interpenetrating network produces a three-dimensional (3D) continuous, conductive pathway and strong interface interaction with high-density hydrogen bonding, thus exhibiting excellent toughness (706.4 KJ/m^–3), conductivity (13.38 S m^–1), sensing performance (GF = 1.52 for a strain range of 1–15% and GF = 3.04 for a strain range of 15–80%), and stability. The physical structure (3D skeleton and interpenetrating network) and chemical interaction (interface interaction and salting-out) achieve energy dissipation. Meanwhile, the sensitivity is enhanced by dual-mode conduction and conductive fiber. Thus, as a typical demonstration, the hydrogel was successfully applied to human motion monitoring and information transmission. In short, this conductive hydrogel serves as a multifunctional platform for developing high-performance e-skin with great potential for wearable electronics.

Composite piezoelectric fiber films were prepared by growing UiO-66-NO₂, Ag/AgCl, and TiO₂ on polyacrylonitrile (PAN) through stepwise in situ growth, and this structure was used as the functional layer of a flexible pressure sensor. The loading of UiO-66-NO₂ onto the fiber films can be controlled by adjusting the molar mass of metal ions on PAN. By controlling the crystallinity and content of metal–organic framework nanoparticles, Ag/AgCl and TiO₂ were synthesized using photoreduction and sol–gel methods, respectively, thereby improving the performance of composite piezoelectric fiber films. The piezoelectric coefficient d₃₃ of the composite fiber membrane increases from 0.03 pC/N of pure PAN to 11.209 pC/N. The films show good flexibility and a Young’s modulus of 1.365 MPa. The sensor boasts an exceptionally high sensitivity, a rapid recovery/response duration of 19 ms/12 ms, and a consistent loading/unloading frequency for a period exceeding 30,000 s of cyclic excitation. Not only that, but the synergistic effect of the ternary components shows excellent inhibitory properties against Staphylococcus aureus. This sensor plays an important role in fields such as human skin antibacterial, human movement monitoring, human medical health, and human energy harvesting.

Developing advanced strategies that are easy to implement and highly energy-efficient to prepare high-performance polymer foams is of paramount importance for practical applications. Here, we report a method that can transform low-value styrene-maleic anhydride copolymer into high-value polymer foam through a simple and low-energy-consuming process. SMA was prepared via self-stabilized precipitation polymerization (2SP), followed by partial ammonolysis, mechanical foaming, and chemical cross-linking to obtain hydrogel foams. The hydrogel foams were then converted into ultralight and high-performance polymer foams using low-energy ambient pressure drying and imidization at 180 °C. The obtained polymer foams have ultralow density (0.028 ± 0.003–0.049 ± 0.004 g/cm³), high porosity (93.38–95.28%), low thermal conductivity (0.030 ± 0.001–0.034 ± 0.002 W/m K), excellent cyclic compressibility, and strong oil absorption capacity (up to 20.3 ± 1.0 g/g). Owing to the simplicity and efficiency of the present strategy, as well as the structural diversity and superior performance of maleic anhydride copolymer-based foams, widespread application in diverse fields such as building insulation materials can be expected.

The widespread use of petroleum-based plastics has caused severe pollution to global ecosystems. Therefore, the development of sustainable and biodegradable eco-friendly materials is urgently needed. This study successfully prepared a multifunctional composite film (PVA-FA/TA) by introducing functional folic acid (FA) and tannic acid (TA) into poly(vinyl alcohol) (PVA) via hydrogen bonding cross-linking. Results indicate that the PVA-FA/TA4 composite film exhibits shielding efficiencies of 99.998 and 100% against UVA and UVB radiation, respectively, while maintaining high transparency in the visible spectrum. Furthermore, the composite film demonstrates remarkable free radical scavenging capabilities, achieving maximum DPPH and ABTS radical scavenging rates of 94.27 and 95.29%, respectively. Moreover, the PVA-FA/TA composite film demonstrated significant antibacterial effects against both Escherichia coli and Staphylococcus aureus. Beyond functional advantages, the PVA-FA/TA composite films are recyclable and reusable, reducing resource waste. Most importantly, complete degradation occurs within 100 days when discarded in soil, further mitigating environmental pollution. Overall, this study provides a feasible and scalable approach for designing next-generation functional film materials with comprehensive protective capabilities.

With the rapid development of flexible wearable electronic devices, various conductive gels have been developed and displayed great application potential in health monitoring, intelligent manufacturing, sensing, and other scenarios. However, their poor underwater adhesion and intrinsic swelling remain the main defects that usually limit their applications in wet and underwater environments. As such, an eco-friendly and cost-effective plant protein-based conductive gel is developed by using the gliadin of wheat gluten, tannic acid (TA), and poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) as raw materials. Due to the delicate balance of hydrophilic hydroxyl groups and hydrophobic backbones of gliadin, the resultant gliadin/TA/PEDOT:PSS gels demonstrated excellent ultrahigh stretchability (≥2200%), instantaneous and robust underwater adhesion ability, excellent antiswelling (42% after 7 days), and underwater adhesion stability (≥100 days). Meanwhile, various dynamic hydrogen bonds endowed the gels with excellent underwater self-adhesive properties under different aquatic environments and underwater self-healing ability. In addition, the gliadin/TA/PEDOT:PSS gel-based sensors demonstrated significant potential for continuous human motion monitoring both in air and underwater and enabled information transmission through the Morse code underwater. The potential applications in biomedical sensing have been approved by constructing the gliadin/TA/PEDOT:PSS gel-based electrodes for ECG health monitoring. Consequently, this eco-friendly, sustainable, and scalable production plant protein-based gel holds significant potential as flexible electronics for amphibious sensing applications.

The development of nanostructured coatings capable of physically disrupting viral envelopes presents a compelling strategy for passive antiviral surfaces. In this study, coarse-grained molecular dynamics (MD) simulations were employed to investigate the rupture of a viral envelope induced by a thermoresponsive hyperbranched polymer brush, comprising a flexible backbone with mixed-functionality side chains. The simulations revealed a distinct four-stage “capture-and-disrupt” mechanism: (i) vesicle approach and adsorption driven by polymer configurational entropy and surface confinement, (ii) electrostatically guided insertion of polymer side chains into the membrane, (iii) localized puncturing and thinning of the lipid bilayer via cooperative electrostatic and hydrophobic interactions, and (iv) progressive envelope disintegration through membrane destabilization. This interplay between entropic confinement, electrostatics, and hydrophobicity provides a general physical framework for virus–polymer interactions. Remarkably, viral rupture occurred within 20 ns across a wide temperature range of 250–325 K (−23 to 52 °C), underscoring the robustness of the physical disruption pathway. This work provides the first molecular-level simulation of a viral envelope rupture, through purely physical effects (chain entropy, electrostatics, and hydrophobicity), induced by a thermally tunable multicomponent hyperbranched polymer brush. The resulting polymer physics–based mechanism enables rational design of synthetic antiviral nanocoatings for advanced materials in healthcare, filtration, and public infrastructure.

The development of eco-friendly, solvent-free, and low-VOC coatings is essential for achieving sustainable protection of metallic surfaces. In this study, a phosphate-functional acrylate monomer, phosphated methacrylate (PMA), was synthesized through an epoxy ring-opening reaction between glycidyl methacrylate (GMA) and phosphoric acid without the use of any external catalyst. The resulting PMA was incorporated into a waterborne acrylic system via mini-emulsion polymerization to produce highly stable phosphated acrylic emulsions (PAE) with a solid content of 38–40 wt % and uniform particle sizes of 125–161 nm (PDI < 0.02). The emulsions showed excellent colloidal stability for over 180 days with a high zeta potential (−52 mV), confirming strong electrostatic stabilization. Structural and morphological analyses using FTIR, NMR, and SEM-EDS confirmed the successful incorporation and homogeneous distribution of phosphate groups within the polymer network. The resulting coatings demonstrated improved thermal stability, with degradation temperatures increasing from 396 °C for the pure acrylic to 416 °C for the 2.5 wt % PMA film. Mechanical testing revealed an increase in surface hardness (up to 4H) and a 2.6-fold improvement in adhesion strength, attributed to enhanced interfacial bonding and restricted polymer chain mobility resulting from the phosphate functionalities. Electrochemical studies, including EIS and potentiodynamic polarization, revealed exceptional anticorrosive performance of the 1.0 wt % PAE coating, characterized by a very low corrosion current density (I_corr = 3.5 × 10^–11 A), high charge transfer resistance (R_ct = 2.25 × 10⁸ Ω), and a low corrosion rate (4.1 × 10^–7 mmpy). These results demonstrate that PMA effectively enhances both adhesion and corrosion protection, providing a scalable, sustainable route to high-performance phosphate-functional waterborne acrylic coatings for long-term industrial applications.