Macromolecular Rapid Communications最新文献

This study reports the development of elastomeric mesoporous polyurethane (PU) membranes for bioartificial pancreas applications in type 1 diabetes treatment. The membranes are designed to exhibit semi-permeable properties, enabling insulin diffusion while restricting larger immune molecules, such as immunoglobulin G (IgG). Although electrospinning is a widely used technique for fabricating porous membranes for controlled drug release, it typically results in an average pore size on the order of few micrometers, which is two orders of magnitude larger than the mesoporous scale required. In this work, a green-electrospinning process using waterborne PU suspension and poly(ethylene oxide) (PEO) is employed, followed by thermal annealing and washing steps. The resulting membranes exhibit a controlled pore size in the mesoporous range (≈20 nm measured by capillary flow porometry). Diffusion tests confirmed selective permeability, with a recovery rate of 25% for insulin and a recovery rate below 5% for IgG, meeting therapeutic needs. In vivo characterizations show no degradation and good biocompatibility of the membranes without chronic inflammation. Moreover, mechanical characterization demonstrates the membranes' flexibility and strength, making them suitable for minimally invasive surgical implantation. These findings underscore the potential of PU membranes for long-term biomedical applications, addressing critical challenges in permeability and mechanical stability.

Adhesives are indispensable in both daily household applications and advanced industrial settings, where they must deliver exceptional bonding performance. Ionogel adhesives, which feature a supporting polymer network infused with ionic liquid (IL), have emerged as promising candidates due to their unique structural and functional properties. The presence of ionic species within ionogels promotes non-covalent interactions-such as ionic bonds, ion-dipole interactions, and hydrogen bonding-that enhance both cohesion within the material and adhesion to various substrates. These characteristics make ionogels ideal for applications that require robust adhesive performance, especially in demanding environments. Despite the growing interest in ionogel adhesives, a comprehensive review of the latest advancements in this area is lacking. This paper aims to fill this gap by categorizing ionogel adhesives based on their composition and discussing strategies to enhance their adhesive properties. Additionally, novel ionogel adhesives designed for specific applications are highlighted. Finally, the current state of research is summarized, and offers insights into the challenges and future opportunities for the development of ionogel adhesives.

Photocatalytic production of hydrogen peroxide (H₂O₂) represents a significant approach to achieving sustainable energy generation through solar energy, addressing both energy shortages and environmental pollution. Among various photocatalytic materials, covalent organic frameworks (COFs) have gained widespread attention and in-depth research due to their unique advantages, including high porosity, predesignability, and atomic-level tunability. In recent years, significant progress has been made in the development, performance enhancement, and mechanistic understanding of COF-based photocatalysts. This review focuses on the latest advancements in photocatalytic H₂O₂ production using COFs, particularly emphasizing the rational design of COF structures to regulate catalytic performance and exploring the fundamental processes involved in photocatalysis. Based on current research achievements in this field, this paper also discusses existing challenges and future opportunities, aiming to provide a reference for the application of COFs in photocatalytic H₂O₂ production.

Phenolic resins (PRs) are known for their exceptional performance due to their 3D cross-linked structure formed during curing. However, this crosslinking makes them non-reprocessable and difficult to recycle, leading to significant environmental pollution and resource waste. In this study, the reactivity of the phenolic hydroxyl group in thermoplastic PR (abbreviated as NR) is utilized to introduce a highly stable nitrogen-coordinated cyclic boronic ester (NCB) group into traditional carbon-chain polymers with the aid of aliphatic isocyanates. This dynamic cross-linked polymer, based on NCB linkages, not only deforms conveniently under appropriate stimuli but also retains excellent dimensional stability and mechanical properties in service environments. This approach gives full play to the good processability and mechanical performance of NR, enabling the closed-loop recycling of waste phenolic resins. This method provides a promising solution for sustainable and efficient recycling, offering a novel pathway to reduce the environmental impact of phenolic resins.

A series of hybrid composite membranes including polymer-metal-organic frameworks (MOFs), are synthesized using sulfonated Fe-MOF and sulfonated polytriazole (PTSF). After being post-modified by 1,3-propane sultone, the obtained Fe-S MOF is incorporated into the polytriazole polymer matrix through the solution blending method. Additionally, a series of polytriazole with a degree of sulfonation of 60 is prepared, with the percentage of the Fe-S MOF ranging from 3 to 9 weight percent. A comparison is made between the properties of these hybrid membranes and those of the pristine membranes. The hybrid membranes demonstrate a high degree of solubility in every solvent that is employed. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) confirm that the MOF is distributed uniformly throughout the polymer matrix. Moreover, well-separated morphologies are confirmed by transmission electron microscopy (TEM). The prepared hybrid membranes demonstrate enhanced proton conductivities, water absorption, and swelling, all of which are accomplished without influencing the oxidative stability values.

Enzymes are essential biological catalysts, which have merits such as specificity, high efficiency, and mild-acting conditions. Due to the characteristics of enzymes, problems such as poor operational stability and difficulty in reuse limit the practical application of enzymes. These problems can often be solved by immobilization of enzymes. Commonly used enzyme immobilization materials include biochar, chitosan, polymer, and metal-organic frameworks, which often do not match the nature of the enzyme. This study utilizes the self-assembled amino acid hydrogel Fmoc-Y-OMe as the immobilizing material. The hydrogelator Fomc-Y-OMe has advantages like simple synthesis, easy immobilization, environmental friendliness, and good compatibility with proteins. It is able to protect enzyme activity at high temperatures and under a wide range of acid-base conditions and has excellent versatility. In particular, immobilized polyethylene terephthalate degrading enzyme (PETase) can significantly degrade polyethylene terephthalate (PET) film at 70 °C, while free PETase completely loses its catalytic capacity at such high temperatures. The excellent performance of self-assembled hydrogels to protect the catalytic activity of enzymes at high temperatures is highlighted.

Covalent organic framework (COF)-derived carbon materials seamlessly inherit the periodic porous architecture and high specific surface area of their precursors, while simultaneously enabling the confinement of nanoparticles in designated regions. This unique feature mitigates agglomeration, enhances intrinsic properties, and imparts novel functionalities to the resulting materials. Consequently, COF-derived carbon materials have garnered significant attention across diverse fields, including energy, environmental remediation, and biomedical applications. Despite this burgeoning interest, a comprehensive review encompassing the synthesis, classification, and multifaceted applications of these materials remains scarce. In this context, the state-of-the-art advancements in COF-derived carbon materials are reviewed systematically here. It categorizes the materials, delineates their primary synthesis strategies, and highlights their versatile applications in catalysis, electrochemical energy storage, water treatment, sensing, and cancer therapy. Lastly, fresh insights into the challenges and future prospects of COF-derived carbon materials, paving the way for their expanded exploration and utilization are offered here.

Bond-exchangeable cross-linked materials, including covalent adaptable networks and vitrimers, exhibit numerous advantageous properties such as reprocessability, recyclability, and healability. These features arise from the relaxation and diffusion of network polymers facilitated by bond exchange within the network. The application of these materials in functional adhesives is particularly promising, given the growing demand across various industries. It is well established that vitrimer films can adhere to a wide range of substrates. In this study, a novel concept of bond exchange-based adhesion between different polymers is introduced, specifically noting that each polymer does not inherently possess bond-exchange capabilities. The key feature lies in activating bond exchange exclusively at the interphase. Significant adhesion between commercial thermoplastic polyurethanes and cross-linked poly(acrylate)s with hydroxy side groups randomly is demonstrated, achieved through transcarbomoylation bond exchange at the contact interphase. The incorporation of a small amount of bond exchange catalyst is crucial for enhancing adhesion, and both adhesion strength and fracture behavior can be manipulated through specific heating conditions. Overall, this study explores a new functionalization approach using the bond exchange concept, contributing to the development of a practical adhesion technique that eliminates the need for traditional adhesives.

Hydrophobic porous materials are of significant interest due to their potential for various large-scale industrial applications. In this study, we introduce the synthesis of a hydrophobic fluorine-containing covalent organic framework (F-COF), TAPB-TFA, using a low-temperature method, along with its applications in liquid marbles and oil/water separation. By a scandium(III) trifluoromethanesulfonate-catalyzed Schiff-base reaction, uniform spherical TAPB-TFA particles at the nanoscale are successfully synthesized. Results show that TAPB-TFA exhibits high crystallinity, excellent thermal and chemical stability, as well as superoleophilic/hydrophobic properties. The hydrophobic TAPB-TFA particles can be utilized to create various liquid marbles that exhibit excellent shape reconfigurability. Experiments confirm the outstanding performance of TAPB-TFA in separating oil/water mixtures and water-in-oil emulsions, achieving a separation efficiency of over 98.5%. The analysis concludes that the exceptional separation performance of TAPB-TFA is attributed to the synergistic effects of surface wetting-induced aggregation and size-sieving. TAPB-TFA demonstrates significant potential for applications in the environmental and energy sectors.

Preparation of irreversible sp² carbon-conjugated covalent organic frameworks (sp²c-COFs) with specific porosity, easy structural functionalization, high chemical stability, and unique π-electron conjugation structure (especially the combination of π-π stacking interactions and conjugation system), can remove the barrier of electron transfer and provide a unique advantage for photocatalytic water splitting. Herein, based on three kinds of reactions (Aldol condensation reaction, Knoevenagel condensation reaction, and Horner-Wadsworth-Emmons reaction) and guided by the precise modulation of ligand structure and topology, this review summarizes the synthesis of sp²c-COFs and their applications in photoelectrocatalytic water splitting (hydrogen evolution and oxygen evolution reactions). Furthermore, challenges and possible research directions for sp²c-COFs in photocatalytic water splitting are also provided.