Materials Science and Engineering: R: Reports最新文献

Since the last century, the abundance of MXenes, two-dimensional (2D) transition-metallic carbides/nitrides isolated from multilayer MAX states, has gained considerable attention in the research of 2D transitional metallic borides. Researchers originally described a novel class of 2D transition metallic borides as MXene precursors in 2017 and gave these the fast moniker MBenes. MBenes have garnered significant attention in the fields of nanotechnology, physical science, and chemistry during the last five years. MBenes have a potential prospect, because they possess numerous appealing features and are being extensively explored for energy conservation and electrocatalysis purposes. However, the research study of MBene is still in its initial phases, presenting numerous predicted characteristics and impacts that have yet to be examined. Similarly, the computational predictions and primary experimental efforts reveal the extensive chemistry, exceptional reactions, substantial mechanical properties, high electrical conductance, transitional features, and potential for energy capturing of these materials. MBenes have a higher range of structural complexity in comparison to MXenes, since they possess various crystallography configurations, polymorphism, and undergo structural transitions. These characteristics complicate the process of synthesizing and separating them into single flakes. This review initially provides a comprehensive overview of MBenes, describing them as a collection of 2D transition metallic borides, that have sandwich-like structures formed from multilayer MAB phases. Next, we discussed the advancement of synthesis techniques, characteristics, distinctive properties, morphology, and potential applications of MBenes for energy conservation and electrocatalysis processes. The continuous challenges with performing experimental synthesis and making computational predictions were thoroughly discussed, along with the potential and future possibilities of MBenes.

The ubiquitous electromagnetic interference and pollution have become a deteriorating issue with the rapid advancement of wireless communication technologies and devices. Developing enhanced microwave absorber is a feasible and persistent research hotspot to counter serious electromagnetic radiation problems. To this end, state-of-the-art low-dimensional materials, including zero-dimensional, one-dimensional, two-dimensional, and mixed-dimensional nanoarchitectures have sprung up on account of their built-in merits including the modulable crystal and electronic structures, exquisite nanoarchitectures, and quantum and dielectric confinement effects. However, the pristine low-dimensional materials perform inferior status in microwave attenuation due to the monotonous dielectric or magnetic responses, the incoordination between wavelength and nanoscale, and semi-empirical electromagnetic attenuation mechanism. Therefore, the elaborate engineering strategies in low-dimensional materials, such as architecture modification, interface engineering, defect engineering, entropy manipulation, and dielectric-magnetic synergy are motivated to contend for enhanced microwave absorption performance. This review provides the cutting-edge progresses of engineering strategies for low-dimensional microwave absorbers. Firstly, the underlying microwave attenuation mechanisms of low-dimensional microwave absorbers are introduced thoroughly. Then, the leading-edge engineering strategies and low-dimensional microwave absorbers inspired by the basic principle of microwave attenuation are summarized and outlined. In the end, the challenges, and outlooks for engineering strategies in low-dimensional microwave absorbers are combed to pinpoint the long-term development orientation.

Though the application-promising photovoltaic technology named organic solar cells (OSCs) have been close to 20% benchmark power conversion efficiency (PCE) within fabrication friendly single-junction devices, these achievements are enabled by polymer donors based on benzodithiophene cores, requiring toxic production steps. Whilst, the bio-renewable benzo[1,2-b:4,5-b′]difuran unit constructed polymer donors cannot yield comparable efficiency, though their lower steric hindrance is widely appreciated. OSC field has paid great attention on optimizing their performance by chemistry design, yet the device engineering is relatively neglected compared to what have been done on the benzodithiophene side. Here we report a new dual additive strategy of simultaneously applying volatile (2-CN) and non-volatile (MF) solid additives to reduce non-radiative voltage loss and boost charge generation, via an occupying evaporated left vacancies in polymer matrix process. Consequently, the target system D18-Fu:L8-BO’s efficiency is promoted to 19.11%, representing the cutting-edge level of this research topic.

Due to ever-increasing environmental concerns, lead-free piezoceramics have been studied for more than half a century with the purpose of replacing toxic lead-based counterparts. A series of notable breakthroughs have been reported in perovskite-structured lead-free piezoceramics, such as ultra-high piezoelectric and strain properties. By contrast, the development of the temperature stability of lead-free piezoceramics has left far behind and has always been the one of the biggest hindrances for practical applications. In this context, we have summarized the most cutting-edge advances in the temperature stability of perovskite-structured lead-free piezoceramics. We first emphasized the measurement methods of evaluating temperature stability, then summarized the regulating strategies (including phase boundary engineering, texturing, composite ceramics, defect engineering, quenching, and others) used for improving the temperature stability of these lead-free piezoceramics, and addressed the physical mechanisms from a multi-scale view. Finally, we concluded advantages and disadvantages of these strategies and provided our perspective on the challenges and future research of the temperature stability. We hope that this timely review could help the development of the temperature stability of lead-free piezoceramics towards practical applications.

In light of escalating biomedical demands across diverse diseases, there arises a pressing need for the development of sophisticated biocompatible materials exhibiting augmented biological functionality. Chitosan, a cationic polyelectrolyte copolymer of natural origin, distinguishes itself through its extraordinary biological properties, positioning it as a promising starting material to develop versatile biomedical materials. Tremendous attention has been directed towards the creation of high-performance biocomposites, achieved through the strategic manipulation of chitosan’s structure or its derivative, along with the amalgamation of other biopolymers. This comprehensive review intricately explores recent advancements in chitosan-based biofunctional materials, delving into formulations involving various biopolymers including polysaccharides and proteins. It places specific emphasis on the progress in chitosan chemistry and materials development, encompassing particles, hydrogels, aerogels, membranes, films, and sponges. Also, this review critically evaluates the development and functional properties of biofunctional chitosan–biopolymer composite materials, spotlighting interactions, both dynamic covalent and noncovalent, and their pivotal roles in materials formation. These interactions may either be inherent or realized through chemical modification such as “Click” chemistry, polymer grafts, mussel-inspired chemistry, and selective oxidation. Furthermore, the text illustrates the current and potential biomedical applications of these biofunctional composite materials, spanning from wound dressing to tissue engineering (skin, bone, cartilage, and nerve), the controlled release and targeted delivery of drugs/bioactive compounds, biosensing, and 3D printing. Additionally, it addresses critical challenges within the field, posits potential solutions, and provides a forward-looking perspective on the future directions of functional biomaterials and design strategies.

Nanoscale lattices formed through the art of controlled self-assembly hold a promise for the creation of advanced materials with diverse applications. These versatile particles, boasting exceptional attributes such as colloidal stability, tunable sizes, and an array of sophisticated shapes, allow access to a vast multifunctionality. In this context, the controlled self-assembly of colloidal metal-organic framework (MOF) particles is a promising field that encourage scientists to continue exploring across the limits of what is possible. A thorough investigation of this new field of study reveals the possibility of influencing a future in which innovation and creativity converge to produce a wide range of applications. In this review, we present a comprehensive overview of the self-assembly of colloidal MOF (CMOF) particles into ordered superstructures, with a focus on the underlying principles governing the self-assembly of CMOF, design and synthetic strategies, as well as their self-assembly mechanisms. In addition, the stability of CMOF particles is highlighted, emphasizing efforts and strategies to ensure their reliability. Finally, we offer some insights and perspectives for the future development and the potential application of CMOF, reflecting the great potential and rapid development of this interdisciplinary research field. We aim to provide new insights into MOF particle self-assembly and further guide future research for large-scale applications.

Rewritable paper (RP) which takes advantages of stimuli-responsive color-changing materials/smart materials and can be used multiple times has been demonstrated to hold potential to reduce human waste of paper and alleviate the increasingly severe environmental issues. To make the RP closer to the way that people are accustomed to reading and more practical for daily life, interest and effort toward smart materials with clearly visible or naked-eye color-switching properties are particularly important. In this review, depending upon the stimulation protocol, five types of stimuli (thermo-, water-related-, light-, stress-, and electric-field-) smart chromogenic materials and systems with visible color switching applied in light absorptive display for RP are focused on. In each section, different stimulus-chromic molecules and their corresponding systems are discussed to explore the design concepts, methodologies, working mechanisms, and pros and cons of various chromogenic materials used in light absorptive RP. In addition, the challenges and prospects are sketched to provide strategies to explore more smart materials for high-performance RP and its relative techniques.

Powder-based additive manufacturing (AM) is revolutionizing the fabrication of advanced engineering metallic materials, including aluminium (Al) alloys, which are the workhorse materials in automobile and aerospace industries. However, challenges remain in the wider applications of AM to produce Al components due to the high tendency to form coarse, textured columnar grains, which causes hot-cracking and severe property anisotropy. The recent adoption of inoculation treatment in AM of Al alloys has been successful in achieving grain refinement, cracking elimination and property improvement, which is a step forward in this field. This paper surveys the emerging researches on inoculation treatment of AM-fabricated Al alloys and provides a comprehensive overview of different inoculation techniques for AM, the refining efficiencies of various inoculants and their underlying mechanisms. The uniqueness of this review includes substantive discussions on the mechanism of epitaxial grain growth during AM and a succinct comparison of the refining efficiency based on both experiment and crystallographic modelling. Critical challenges in the most recent alloy design strategy embedded with inoculation treatment are also discussed. Accordingly, outlooks for the immediate future in this area, gaps in the scientific understanding, and research needs for the expansion of AM in fabrication high-performance Al alloys are provided.

Covalent organic frameworks (COFs) are crystallized porous organic polymers with persistent permeability and stable coordinated frameworks. COFs functional sustainability without compromising on controllability in synthesis and flexibility in tuning pre-designed physical structure makes it an exciting polymeric material in comparison to traditional regular ones. The topology design patterns can govern the extended permeable polygon in a particular structured pattern. Co-condensation techniques facilitate the generation of pre-configured basic and highly ordered configurations using synthetic procedures. These two components chemical interactions have made significant advancements in the recent years to establish the basis of the COFs field. COFs emergence in the domain of innovative organic nanomaterials offers an effective chemical framework for complex structured design and tailored operational enhancement because of the availability of chemical subunits and the diverse range of topologies and linkages. We aim to conduct a comprehensive analysis of the COF research field, offering a historical perspective on the fundamental aspects of COFs by examining the progress made, especially, in configuration setup and chemically synthesized interactions, to demonstrate the various functionalities and differences within the system to highlight the core investigations progressing the advancements in field and potential of multiple capabilities by describing the structural capability associations based on interrelationships with photoelectrons, photons, gaps, spins, atoms, and particles, to address the critical and challenging concerns.

Mobility is a critical parameter influencing the overall performance of organic solar cells (OSCs). Herein, we innovatively elucidated the intricate interrelation between the photovoltaic molecular structures and the methodologies employed for the extraction of charge carrier mobility in OSCs. We proposed a simple yet effective principle to accurately extract charge carrier mobility values using the standard space-charge-limited current (SCLC) measurement, while critically assessing theoretical and experimental deficiencies through the drift-diffusion analysis. It was found that field-dependent charge transport is necessitated to describe the prominent long-range intrachain hopping carrier behavior in polymers, while short-range intermolecular hopping results in trap-involved charge transport within small molecular acceptors. Based on the above understanding, a synergetic inter/intra-molecular hopping strategy was proposed to fabricate thick-film all-polymer OSCs, and an unprecedented power conversion efficiency (PCE) of 16.61 % was achieved in the 300 nm PM6:PY-IT OSC. This work not only presents a precise and straightforward approach for measuring mobility values, but also provides a significant reference about charge carrier transport to make optimal decisions regarding photovoltaic material design and device fabrication process of high-performance OSCs.