Progress in Polymer Science最新文献

The past decades have witnessed the rapidly growing interest in polymer films as the most commonly used packaging material due to their lightweight, versatility, low cost, and ease of manufacturing. However, there is a noticeable mismatch between the demanding requirements of various oxygen- or humidity-sensitive commodities and the poor barrier properties of single-component polymer films, thus giving rise to food spoilage, drug failure, as well as corrosion damage of electronic devices. In this review, we provide an in-depth introduction on the most promising strategies for developing high barrier polymer packaging films, including surface coating, polymer blending, and polymer nanocomposites. Specifically, the types of surface coatings, the dispersed phase morphology in polymer blends, the main factors for polymer nanocomposites containing large-aspect-ratio nanoplatelets, their dispersion morphology, the interfacial structure, and the crystalline structure of the matrix polymers can be tailored to maximize the gas barrier performance. Also, current challenges and perspectives for future development of high barrier polymer packaging materials are proposed. The new insight into the relationship between polymer processing, microscopic architecture, and barrier properties of polymer materials are expected to provide a valuable guide for developing high-barrier polymer packaging materials.

Polymer coatings of nanometric thickness are about to enter in everyday life as part of a wide range of applications such as protective layers, stimuli-responsive membranes or as components of flexible electronics devices. In the past 30 years, these polymer nanomaterial systems have been at the center of research interest due to the opportunities to control relevant material properties like the phase transition temperature, viscosity, permeability, or thermal expansion by variation of the film thickness. One of the key factors responsible for the deviation from bulk behavior is known as 1D confinement that describes the increasing impact of interfacial layers when reducing film thickness. This review provides a comprehensive discussion of the role of the free surface at the boundary with air and the interfacial layer in proximity of a supporting substrate on the crystallization of thin polymer films. First, the dynamics of polymers near the free surface and its impact on the crystallization of films is discussed. Subsequently, the effect of solid substrates on crystallization in thin films is elaborated, including the formation of irreversible adsorption layers, alteration of crystalline structure and the kinetics of crystallization. Subsequently, the competition between surface and interface effects on the formation of ordered structures in thin polymer films is discussed. A perspective on challenges and opportunities in the field of thin film crystallization is provided to inspire future research and development in the field. This review thus provides an up-to-date analysis of current understanding of crystallization of polymer glasses under 1D confinement, aimed at supporting the manipulation and control of the properties of polymer-based nanodevices.

Polymers and polymer composites with advanced functions have attracted great attention following the development of modern science and technologies. Nevertheless, damages of microstructures and variations of chemical constitutes are inevitably induced during their manufacturing and operation, causing undesired attenuation or even loss of functionalities. To address the problems, self-healable functional polymeric materials, which focus on autonomous restoration of non-structural functionalities for improving the lifespan and durability, have emerged in recent years as a huge surge of interest because of their apparent potential benefits. As dictated by the diverse working principles of the individual functionalities, the technical advance of self-healing functional polymers and composites exhibits distinct characteristics from that of self-healing structural materials specializing in strength recovery. This review summarizes the state-of-the-art achievements in the field, and discusses the common features and issues in most of the reported self-healing functional materials including healable electroconductive, thermally conductive, dielectric, optically transparent, superhydrophobic, superhydrophilic, and power conversion and storage related polymers. The review will subsequently discuss (i) the damage modes relating to different causes, (ii) the mechanisms of self-healing based on chemical and physical methodologies, and (iii) molecular level design schemes and synthesis strategies for self-healing functional polymeric materials. The advantages and inadequacies of representative works are discussed, and the critical challenges and opportunities for future research are highlighted. It is hoped that the present article would inspire more innovative explorations of self-healing functional polymeric materials, as well as promote their practical application.

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.