ACS Applied Polymer Materials最新文献

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.

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.

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.

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.

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.

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.

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.

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.

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.