Progress in Polymer Science最新文献

The materials of future depend a lot on properties that are due to “non stable” molecules. Hence, Dynamic Covalent Bonds (DCB) are covalent bonds that are labile under specific stimuli and are integral to the design of next generation materials. Alkoxyamines R¹R²NO—R³ exhibit a unique C—O DCB that is nonsymmetric between the adjacent O- and C-atoms. This bond can be cleaved homolytically, heterolytically and mesolytically in response to a wide variety of physical, chemical and biological stimuli, and the kinetics and thermodynamics of cleavage can be tuned on-demand by varying the structure of R¹, R² and R³. Alkoxyamines are easily incorporated into polymers via nitroxide mediated polymerisation (NMP) however, their dynamic covalent properties are yet to be fully exploited in materials sciences. This is in part because reports on C—ON activation are scattered through the broader synthetic, physical and biological chemistry literature, and a comprehensive review of them has been lacking. Herein, 20 leading C—ON activation processes using UV-light, surface plasmon resonance, magnetothermy, electrochemistry, chemical oxidation, protonation, non-covalent bonding, sonication, enzymatic activation among others, are presented and discussed, along with primary examples of their application.

Solar-to-chemical energy conversion through artificial photosynthesis is an ideal route to address the global energy crisis and realize carbon neutrality in the future. Over the past decade, two-dimensional conjugated polymer frameworks (2D CPFs), including conjugated microporous polymers, covalent organic frameworks, and covalent triazine frameworks, have emerged as a promising class of photocatalysts for solar fuel generation. They exhibit highly tunable chemical and optoelectronic structures which can be precisely controlled at the molecular level. Meanwhile, the 2D planar structure with in-plane periodicity offers many unique features for solar-driven catalytic energy conversion, including large surface areas, high absorption coefficients, efficient charge transport, and facile formation of heterostructures. In addition, their surface active sites can be rationally constructed from numerous molecular building blocks to optimize their photocatalytic performances. Herein, we comprehensively summarize recent progress in developing 2D CPFs for solar fuel generation from water, including photocatalytic overall water splitting, hydrogen peroxide production, carbon dioxide reduction, and nitrogen fixation. Basic principles in these photocatalytic reactions are described. In-depth insights into the structure-property relationships between 2D CPFs and their reaction mechanisms are discussed in detail. Moreover, recent advances in applications of 2D CPFs in photoelectrochemical energy conversion are also highlighted. Finally, the remaining challenges and research opportunities for the future development of efficient 2D CPFs toward solar fuel generation are presented.

Flexible energy storage devices have received much attention owing to their promising applications in rising wearable electronics. By virtue of their high designability, light weight, low cost, high stability, and mechanical flexibility, polymer materials have been widely used for realizing high electrochemical performance and excellent flexibility of energy storage devices. In this review, flexible energy storage devices including supercapacitors and batteries are firstly introduced briefly. Then the design requirements and specific applications of polymer materials as electrodes, electrolytes, separators, and packaging layers of flexible energy storage devices are systematically discussed with an emphasis on the material design and device performance. The remaining challenges and future directions are finally summarized to guide future studies on the development of polymer materials for flexible energy storage devices.

Nanoparticle assembly offers a versatile tool for constructing new structural materials with emergent or collective properties beyond individual nanoparticles. The achievement of desired properties and functions of these assembly materials often require delicate control over the interactions between nanoparticle building blocks. As of now, tremendous efforts have been devoted to manipulating the interparticle interactions by functionalizing the surface of nanoparticles with different ligands (e.g., small molecules, DNAs, proteins, and polymers). Among others, polymers are particularly attractive, owing to their tailorable molecular structures, rich functionalities, tunable responsiveness, superior biodegradability and biocompatibility, and easy mass production at low cost, etc. In this review, we present a summary of recent advances in engineering interparticle interactions between nanoparticles, especially inorganic nanoparticles with different sizes, shapes, and compositions, by tailoring the structurally defined polymers grafted or absorbed on the surface of nanoparticles. Discussions are focused on various interactions (i.e., steric repulsion, Coulombic interaction, hydrophobic interaction, hydrogen bonding, chemical reaction-induced recognitive interaction, and entropic effect) dominating the assembly of polymer-modified nanoparticles. Furthermore, the effect of external fields (e.g., light field, electric field, etc.) on the interactions between polymer-modified nanoparticles is presented.

π-Conjugated polymers show promising potential in the application of organic photovoltaics, including organic solar cells (OSCs) and organic photodetectors (OPDs) because of merits of light-weight, flexibility, facilely tuned color, large-scaled solution-processability, etc. Over the past three decades, various π-conjugated polymers have been developed owing to the continuous efforts of researchers, which significantly promote the OPVs technology to an unprecedented stage. In order to reveal the relationship among polymer structures to the optical and electronic properties and interchain aggregation and morphology and finally to device performance, it is of great significance to review the progress of π-conjugated polymers for OPVs, particularly for outstanding achievements in recent all-polymer solar cells (all-PSCs), indoor organic photovoltaics (IOPVs), thick-film OSCs, single-component organic solar cells (SCOSCs) and short-wave infrared (SWIR) OPDs. This review highlights general design strategies of π-conjugated polymers for high-performance OPVs, including conjugated backbone engineering, side-chains engineering, regioregularity engineering, halogen substitution and molecular weight control. Then, the development of conjugated polymers for all-PSCs, IOPVs, thick-film OSCs, SCOSCs and OPDs has been summarized. At the end, we summarize the challenges and future directions for studying π-conjugated polymers for OPVs. Therefore, an in-depth understanding of designing π-conjugated polymers is speculated to advance the development of current OPV materials and thus accelerate the ultimate industrialization of the OPV technology.

Polyolefins are the largest-scale synthetic plastics and play a key role in modern society. Their production consumes huge amounts of fossil-derived monomer feedstocks, which unfortunately became discarded wastes after use with a very low recycling ratio, causing severe environmental pollution and huge consumption of non-renewable resources. This lack of sustainability could in principle be solved by reusing the waste polyolefins repeatedly as virgin materials or recovering olefin monomers for re-entering the polyolefin cycle. However, it is challenging due to their chemical inertness (C-H and C-C bonds) and lack of degradation sites along the polyolefin chains. Therefore, to make polyolefins more sustainable, degrading or modifying the waste polyolefins on large scales could facilitate their reuse as virgin polyolefins or recovery to polymerizable feedstocks, rethinking the design and synthesis from monomer feedstocks could afford inherently recyclable and thus more sustainable polyolefin or polyolefin-like materials. Given the above, this review will introduce recent progress in the rapidly advancing field: 1) Recycling and upcycling to fuels and other small molecule products, olefin monomer, telechelic products, reprocessable and functional polyolefin materials; 2) Increasing sustainability by the de novo design and synthesis of new degradable and reprocessable polyolefin and polyolefin-like polymers.

Porous organic polymers (POPs) have well-defined porosities, high surface areas, and attractive surface chemical functionalities. Because of these properties, POPs and their derivatives, including their pyrolysis (carbonaceous) products, have broad applications in catalysis, absorption, separation, sensing, biomedical engineering, and energy storage/conversion. In particular, both the porosity and morphology of porous materials have crucial impacts on their performance. The controlled synthesis of morphological defined POPs via various assembly approaches offers an effective route to prepare novel nanomaterials with broad application scope in the above-mentioned fields. Therefore, a summary of recent research related to POPs will stimulate researchers to explore this field at a deeper level. This review provides a summary and analysis of progress in the last decade toward the development of morphologically controlled POPs. Established works and recent progress in the synthesis of these materials are first reviewed, followed by the systematic discussion of the methodologies and key parameters for the fabrication of diverse morphology-controlled POPs. The various emerging applications afforded by the POPs are summarized, and special attention is paid to the relationship between the morphology and performance of POP materials. Finally, current challenges in the development of application-driven morphological control are addressed, revealing areas for future investigation. We hope that this review will encourage future investigation of POPs with defined morphologies as well as exploration on hitherto unknown characteries of the morphology derived innovative applications.

Pressure sensitive adhesives are components of everyday products found in homes, offices, and hospitals. Serving the general purpose of fissure repair and object fixation, pressure sensitive adhesives indiscriminately bind surfaces, as long as contact pressure is administered at application. With that being said, the chemical and material properties of the adhesive formulation define the strength of a pressure sensitive adhesive to a particular surface. Given our increased understanding of the viscoelastic material requirements as well as the intermolecular interactions at the binding interface required for functional adhesives, pressure sensitive adhesives are now being explored for greater use. New polymer formulations impart functionality and degradability for both internal and external applications. This review highlights the structure-property relationships between polymer architecture and pressure sensitive adhesion, specifically for medicine. We discuss the rational, molecular-level design of synthetic polymers for durable, removable, and biocompatible adhesion to wet surfaces like tissue. Finally, we examine prevalent challenges in biomedical wound closure and the new, innovative strategies being employed to address them. We conclude by summarizing the progress of current research, identifying additional clinical opportunities, and discussing future prospects.

Supramolecular polymer materials are polymeric structures that are physically crosslinked by non-covalent interactions such as ionic interactions, host-guest complexation and hydrogen bonding. The resulting materials generally display stimuli-responsive behavior and/or healable properties, which makes them excellent candidates for the design of dynamic materials. Inspired by its omnipresence in natural systems, hydrogen bonding has proven to be useful for the development of synthetic materials with dynamic properties. Inspired by the base-pairing in the DNA double helix, Meijer et al. developed the self-complementary quadruple hydrogen bonding unit ureidopyimidinone (UPy), which has a strong dimerization constant (K_dim > 10⁷ M ⁻¹ ). The incorporation of UPy motifs in polymeric precursors led to a plethora of hydrogen bonded materials with applications ranging from artificial arteries to reversible adhesives. This review will focus on design strategies to synthesize these UPy-containing polymer materials, which can be split into three main categories based on the location of the UPy arrays: UPy in the main-chain, UPy in the side-chains or UPy at the chain-ends. In addition to the synthetic routes, the material properties of the resulting UPy-containing supramolecular polymer materials will be discussed.

Patterned polymer thin films are essential components in many devices and applications owing to the multi-functionality, flexibility, lightweight and cost-efficiency. Unfortunately, conventional photolithography needs the use of developers and strippers which contain solvents and reagents that may dissolve, swell or degrade the polymer thin film substrates. Alternatively, non-photolithographic strategies provide alternative options and avoid the complicated optical systems, offering versatile routes for fabricating polymeric micro- and nanostructures. In this review, we summarize the recent progress in non-photolithographic patterning methods including soft lithography, nanoimprint lithography, direct writing, self-assembly of block copolymers, area-selective vapor phase deposition and instability induced patterning. These patterning approaches have been applied to various applications such as chromic devices, polymer light-emitting diodes, sensors, transistors, and protein and cellular engineering and many other scenarios. Finally, the subsisting challenges and future research directions of non-photolithographic patterning approaches are highlighted from the aspect of resolution, reliability and scalability.