ACS polymers Au最新文献

Decarboxylation is an emerging strategy to remediate plastic waste. Herein, we discuss recent advances that leverage activated ester or carboxylic acid decarboxylation to deconstruct polymers. Specifically, we address state-of-the-art strategies that rely on thermolytic, photolytic, or electrolytic stimuli to induce decarboxylation. Throughout, we highlight the key advances of each report and provide our insight on future directions for the field. We anticipate that continued developments in the field will lead to strategies for the controlled deconstruction of versatile polymeric materials.

We investigate the structure of single-chain nanoparticles (SCNPs) on the basis of small angle neutron scattering (SANS) data. The folding of poly-(pentafluorobenzyl-stat-tert-butyl acrylate) precursors in a controlled solvent environment is simulated by using a coarse-grained Monte Carlo model. Simulation results closely follow the experimental signature of compaction at intermediate wave vectors under variation of cross-linker density. The good agreement allows, vice versa, relating structural features observed in scattering experiments with the underlying topological state that emerged during cross-linking. By exploring ensembles in sequence space of the cross-linkable monomers, we show that experimental SCNPs were typically in a sparse state when compared to fractal globules. However, a subgroup of SCNPs with highest compaction shows signatures of the form factor expected for a dense sphere. Hence, we enable the predictive design of soft nanoparticles under variation of solvent quality and sequence for the given precursor and folding chemistry.

Co-(II) complexes, despite their potential as cost-effective alternatives to noble-metal systems, remain underexplored as photocatalysts (PCs) in free radical photopolymerization (FRP). In this study, a series of Co-(II) complexes bearing symmetrical Schiff bases (Co-Ph, Co-EtO, Co-Cl, Co-Me, and Co-t Bu) was synthesized and characterized by FTIR, UV-vis, fluorescence spectroscopy, MALDI-TOF mass spectrometry, cyclic voltammetry, and advanced density functional theory (DFT/TD-DFT) calculations. Their photocatalytic performance was evaluated in three-component photoinitiating systems with ethyl 4-(dimethylamino)-benzoate (EDB) and diphenyliodonium hexafluorophosphate (Iod) for the FRP of trimethylolpropane ethoxylate triacrylate (TMPETA) under UV, violet, and blue LED irradiation. Co-(II) complexes enabled efficient polymerization under optimized conditions, reaching high conversions without an inhibition period under UV irradiation. Co-EtO demonstrated a superior photocatalytic efficiency across all tested wavelengths relative to that of the other Co-(II) complexes evaluated in this study. This enhanced performance is attributed to a synergistic combination of its unique structural, electronic, and electrochemical properties. The proposed mechanism was supported by photolysis experiments, literature data, and free energy calculations, indicating the involvement of both oxidative and reductive pathways.

Additive manufacturing (AM) of polymeric materials is rapidly transforming the biomedical field by enabling the fabrication of patient-specific, anatomically complex structures with precise control over internal architecture. Polymers are especially attractive for AM of biomedical devices due to their cost-effectiveness, abundance, low density, and tunable mechanical and degradation properties, supporting diverse applications in soft and hard tissue engineering, microfluidics, and drug delivery. However, many medical-grade polymers interact poorly with mammalian cells and tissues due to the lack of bioactive surface functional groups, which can hinder their performance in biomedical applications that rely on cell-material interactions such as tissue regeneration. This review systematically surveys physical, chemical, and biomimetic surface modification techniques for AM-compatible medical polymers to improve biomedical applications and targeted functionalities. While much attention has been paid in the literature to surface modification in bone tissue engineering, functional coatings incorporating bioactive molecules and nanoparticles further provide antibacterial, anti-inflammatory, and pro-regenerative functions. A major emphasis of this review is the synergy between AM and surface engineering, enabling simultaneous optimization of internal architecture and surface bioactivitycapabilities fundamentally unattainable by conventional manufacturing techniques. Finally, challenges such as sterilization compatibility and long-term stability of surface modifications are discussed as key to clinical translation.

Reversible addition-fragmentation chain transfer (RAFT) polymerization has gained interest in vat photopolymerization, particularly for enabling postprinting surface functionalization via reactivation of the RAFT agent. In this work, we report the development of RAFT photopolymerizable resins containing up to 50% renewable content using sustainable dimethyl or dibutyl itaconate as primary monomers combined with hydroxyethyl acrylate as a reactive comonomer. A 4-arm polyester cross-linker end-functionalized with itaconic acid (IA), poly-(caprolactone-co-valerolactone)-IA, was synthesized and incorporated into the resin formulation. Photorheology confirmed efficient polymerization, and mechanical characterization revealed elastomeric properties for networks derived from dimethyl itaconate. Digital light processing (DLP) of this formulation enabled the 3D printing of flexible structures, including microneedles. The presence of pendant carboxylic acid groups in the cross-linker imparted pH-responsiveness to the printed objects, allowing for reversible swelling and size changes in response to environmental pH, demonstrating 4D behavior. Leveraging the controlled nature of RAFT polymerization, a two-stage printing approach was employed. After printing with the itaconate-based ink, a switch to a methacrylated polylysine ink enabled surface biofunctionalization. Successful grafting of polylysine was confirmed by atomic force microscopy (AFM) and FTIR spectroscopy. Preliminary results demonstrate antimicrobial activity of the cationic surfaces, as well as the ability to spatially control surface functionalization, exemplified by patterned attachment of fluorescent polylysine.

Polymerization-based strategies have emerged as powerful tools for enhancing sensitivity and enabling user-friendly visual outputs in bioassays. Unlike conventional assays that rely on catalyst- or enzyme-mediated accumulation of molecular products for signal amplification, polymerization reactions produce material-level, macroscopic, or supramolecular structuressuch as hydrogels, polymer films, or insoluble precipitates. This mini review highlights recent advances in polymerization-assisted signal amplification techniques, with a particular focus on detection strategies and polymerization chemistries. We first classify detection approaches according to their readout mechanisms, including direct visual detection and integration with electronic or optical transducers. We then examine representative polymerization reactions employed in bioassays, including enzyme-mediated hydrogelation, nucleic acid polymerization, conductive polymer formation, and controlled radical polymerization. Both enzyme-dependent and enzyme-free systems are discussed, reflecting the growing versatility of polymerization-based platforms for biosensor development.

Hydrovoltaic energy harvesting converts interactions at water-solid interfaces into electricity through capacitive discharge, streaming, and diffusion. Fluorinated polymers such as poly-(tetrafluoroethylene) (PTFE), fluorinated ethylene propylene (FEP), and poly-(vinylidene fluoride) (PVDF) are central to these processes owing to their high electronegativity, hydrophobicity, and chemical stability. These materials facilitate charge separation and storage while offering structural versatility for device fabrication. This review highlights recent progress in applying fluorinated polymers across the three hydrovoltaic mechanisms, with emphasis on structure-property-function relationships that govern interfacial charge dynamics. Approaches for integrating multiple mechanisms and coupling hydrovoltaic devices with complementary energy-harvesting systems are also summarized. Together, these advances underscore the key role of fluorinated polymers in enabling multifunctional hydrovoltaic platforms and point toward strategies for improving performance, durability, and system-level integration.

We developed a set of intrinsic antimicrobial copolymers equipped with a dual-binding mechanism for the bacterial cell surface, targeting both the anionic bacterial membrane through electrostatic interactions and surface proteins through reversible imine formation. These copolymers, containing formylphenyl and quaternary ammonium functional groups, were systematically evaluated for their biological activity as the chemical composition and architecture were varied. These bactericidal polymers exhibit potent antimicrobial activity in NB media against both Staphylococcus epidermidis and Escherichia coli, while also demonstrating excellent in vitro biocompatibility against mammalian and red blood cells. This work expands the chemical repertoire of intrinsic antimicrobial polymers that coalesce with bacterial matter.

Polypeptides are attractive, renewable, and biocompatible materials for broad potential biomedical, pharmaceutical, and regenerative medicine applications. In this study, star-shaped 3-arm amphiphilic polypeptides with self-assembly characteristics were synthesized by ring-opening polymerization (ROP) of N-carboxyanhydride (NCA), incorporating l-leucine and l-lysine to form a core-shell structure. These polymers were thoroughly characterized through various techniques, revealing that their rheological behavior and self-assembly are influenced by factors such as the length of the star-shaped arms, the proportion of hydrophobic amino acids, and the surrounding pH. The synthesized polypeptides can self-assemble into five distinct secondary structures, mimicking natural proteins. Our findings evidence that the design of the block size of the hydrophilic l-lysine core and hydrophobic l-leucine shell shapes the ability to form a physical hydrogel, exhibiting shear-thinning rheological characteristics and a rapid mechanical response. The internal microstructure of the hydrogel is based on a supramolecular self-assembly structure consisting of highly connected nanofibrils.

The increasing global demand for sustainable energy solutions has driven significant advancements in photoelectrochemical (PEC) technologies, particularly for hydrogen production and biomass valorization. A key challenge for PEC cells is the selection of ion exchange membranes (IEMs) that ensure efficient product separation between anode and cathode half-cells while enabling efficient ion transport. Moreover, these membranes also need to show long-term stability. Traditionally, perfluorinated membranes such as Nafion have been widely used due to their high proton conductivity and chemical resilience. However, their high cost, environmental concerns, and the impending regulatory restrictions on per- and polyfluoroalkyl substances necessitate the development of fluorine-free alternatives. This review explores the latest advancements in fluorine-free IEMs for (photo)-electrochemical applications, highlighting their synthesis, physicochemical properties, appropriate characterization methods, and performance metrics. We discuss emerging materials that offer comparable ionic conductivity, durability, and operational efficiency while addressing recyclability and environmental impact. By assessing the potential of these next-generation membranes, we aim to provide insights into their role in advancing photo- and electrochemical systems toward a more sustainable and economically viable future.