With the discovery of the giant magnetoresistance effect(GMR), spintronics has rapidly emerged as a new discipline. Spintronics, which utilizes the spin property of electrons, may combine logic operations, information storage and communication to foster the next-generation electronics. Organic semiconductors are attractive for spintronics because of their intrinsically long spin relaxation time due to their low spin-orbit coupling and weak hyperfine interactions. Organic spin valves(OSVs) are important basic structures to study spin injection and transport in organic materials. This review generalizes the progress of OSVs. The spin relaxation mechanisms in organic semiconductors are summarized briefly. Key scientific questions such as the strategy to realize room temperature spin transport and the sign problem of magnetoresistance in OSVs are specially emphasized. Emerging functional devices which utilize the spin property of electrons such as spin organic light-emitting diode(OLED) and spin-photovoltaic device are introduced. Finally, the future development of organic spintronics is prospected.

Core-shell structured fiber, as a functional composite fiber, has the excellent properties of both core and shell layers. Its special structure and properties greatly broaden the application field of the fibers. Therefore, core-shell structured fiber has become a research hotspot. Electrospinning is an efficient and facile technique for the fabrication of polymer nanofibers, which has attracted much attention in recent years. The method for preparing core-shell structured fibers with controllable structure and morphology is especially useful for guiding its application. The preparation methods of core/shell nanofibers are presented in this review. The methods mainly include single nozzle through phase separation, coaxial electrospinning, emulsion electrospinning, and template method. The major factors for forming the core/shell structure and the effect on the properties of the fibers are discussed in detail. The new research progress of electrospinning core-shell structured fibers in recent years is summarized. The various potential applications in drug controlled release system, tissue engineering scaffold, multifunctional wound dressing, wastewater treatment material, superhydrophobic material, and other fields are also reviewed.

The non-fullerene electron acceptors with broad tunability in molecular structures, light absorption and energy levels used in organic solar cells have been rapidly developed in recent years. P3HT, a representative electron donor in the second-generation organic semiconductor material, has been widely studied for bulk heterojunction organic solar cells(BHJ OSCs). P3HT is a classic electron donor material with low price, good crystallinity and excellent electron mobility. Herein, the progress of P3HT/non-fullerene BHJ OSC in recent years is reviewed. The requirements for the molecular design of non-fullerene acceptors for P3HT are discussed. The key factors for the performance improvement of P3HT/non-fullerene BHJ OSC have also been reviewed. Finally, we prospect the remaining challenges and promising future directions for the P3HT/non-fullerene BHJ OSCs.

Semiconductor quantum dots(QDs) present great potential in applications of light emitting diodes, solar cells and bio-labeling fields owing to their unique optical and electronic properties. Although the traditional Ⅱ-Ⅵ and Ⅲ-Ⅴ type QDs possess appealing emission properties, the intrinsic toxicity of heavy metal elements, such as cadmium and lead, severely sheds doubt on their large-scale commercial applications. As a new kind of fluorescent material that has emerged in recent years, Ⅰ-Ⅲ-Ⅵ multiple QDs are considered as promising alternatives to the traditional binary QDs due to their low toxicity, tunable bandgaps, large Stokes shifts and long photoluminescence lifetime, which have been receiving considerable attention of researchers. In this review, we highlight the current research progress on theⅠ-Ⅲ-Ⅵ QDs. Firstly, the regulation mechanism of the luminescent properties is illuminated on the basis of their structure and composition. Moreover, the emphasis is focused on the current research of the organic and aqueous preparation pathways in recent years. Simultaneously, their primary applications in the lighting and display fields are summarized, and the comparison of the latest research progress of devices betweenⅠ-Ⅲ-Ⅵ QDs and other QDs is made. Finally, we outline the challenges concerning the development of the luminescentⅠ-Ⅲ-Ⅵ QDs and conclude the main future research directions.

With the continuous improvement of the requirements for the power of lithium-ion batteries in electrical vehicles, high-performance lithium-ion batteries are becoming the focus of researchers. As one of the critical components in lithium-ion batteries, membranes play the role of separating the anode and cathode materials and providing the channels for lithium ions to translate. In addition, the thermal stability of membranes can affect the safety of batteries directly. Polyolefin microporous membranes are widely used in lithium batteries for their excellent chemical stability, high mechanical strengths and low cost. However, the poor thermal stability and wettability bring great hidden danger to the wide application of high-performance lithium-ion batteries. As a result, starting from the surface modification of polyolefin microporous membranes, the paper introduces the research progress of polyolefin microporous membranes which are based on polymer surface modification and inorganic nanoparticles, organic-inorganic composites. When introducing the polyolefin microporous membranes based on inorganic nanoparticles, the paper makes a brief introduction to those advanced surface modification methods such as atomic deposition, the chemical vapor deposition method and the physical vapor deposition method. Subsequently, based on the shortcomings of polyolefin, the research progress of other polymer microporous membranes are introduced with respect to the wet process, the phase inversion method, the breath figure method, electrospinning and the in-situ polymerization. At last, the paper makes an outlook for the future researches of high-performance membranes and means to provide a reference for the research and application of high-performance membranes in lithium-ion secondary battery membranes.

Cationic antimicrobial polymers, as a kind of novel antimicrobial material with unique antimicrobial mechanism and high antimicrobial activity, can effectively solve the problem of bacterial resistance, which have caused widespread concern. Although cationic antimicrobial polymers have potent antimicrobial activities, the factors that affect their antimicrobial activities, including the balance of hydrophilicity and hydrophobicity, molecular weight, alkyl chain length, counter ions, and so on, are reviewed. Antimicrobial activity is one of the important factors to evaluate the pros and cons of antimicrobial agents. Thus, it is of great significance for optimizing or developing the safer and more efficient cationic antimicrobial polymers by controlling the factors affecting antimicrobial activity. In this review, multiple antimicrobial strategies of different modes acting on bacteria are firstly summarized. Then, the research progress of natural cationic antibacterial polymers, quaternary ammonium salt polymers, N-halamine polymers, phosphonium and sulfonium salt polymers, guanidine salt polymers and antibacterial hydrogels are listed based on the parameters affecting the properties of cationic antimicrobial polymers. In addition, the antibacterial coatings, membranes or gels fabricated with some cationic antimicrobial are also described. Finally, the current challenges about realizing the clinical application of antibacterial agents and the future perspectives in this field are discussed.

MXene has attracted considerable attention as a new type of two-dimensional layered structural materials owing to its high electron conductivity, large specific area, excellent mechanical properties and unique layered structure, which make it promising for application in energy storage, catalysis and adsorption. MXene and its composites have recently aroused intense interest for rechargeable batteries. Transition metal sulfides and oxides have the merits of high capacity, however suffering from issues of low conductivity, relatively large volume expansion and poor capacity retention during cycling. Combining MXene with these materials can not only increase the specific capacity, but also enhance electronic conductivity and solve the volume change during electrochemical cycling, finally achieving superior electrochemical properties. This review covers the key technological developments and latest progress of MXene composites in sodium ion batteries and potassium ion batteries. Starting from a brief introduction of the background of sodium ion batteries, potassium ion batteries and MXene, we mainly focus on research progress on synthesis and application in sodium ion batteries, including sulfides, oxides, and carbonaceous materials. The study on potassium ion batteries is still in its infancy. Current status of MXene and its composite in potassium ion batteries have also been summarized, also current challenges and future perspectives in the application of MXene materials are discussed.

Lignin is the second most abundant biomass and the only natural source of aromatic hydrocarbons. The great challenge of the low-level utility of lignin remains for the biochemical industry. Recently, grafting modification of lignin via atom transfer radical polymerization(ATRP) has attracted much interest as an important improvement strategy for lignin. Varied kinds of lignin-based copolymers with different properties are synthesized via ATRP. This review summarizes the progress of grafting modification of lignin via ATRP, including the monomers, catalysts, copolymer structures and properties. Moreover, the outlook and challenges for lignin-based copolymers are discussed.

Traditionally, calcium carbide is a widely used raw material in organic synthesis. It is always first converted into acetylene gas and subsequently used to prepare organic compounds. Acetylene gas is inflammable and explosive, posing the problem of storage and transportation. In addition, directly using acetylene gas as precursor needs harsh reaction conditions and complicated operation, which greatly limits its further application. Recently, it is shown that calcium carbide could be quickly prepared from renewable biochar at relatively low temperature. Such progress allows calcium carbide as a green and economical raw material. Therefore, the direct use of calcium carbide as a green acetylene source instead of acetylene gas and acetylene reagent to prepare various important organic chemicals will be a simple and green way. In this review, the major progress to date, as well as related reaction types and reaction mechanism towards the application of calcium carbide for specific organic reaction and synthesis have been summarized. The trend of using calcium carbide as a solid acetylene source to construct organic compounds is also prospected.

Natural products refer to the natural compounds produced by the secondary metabolism of the organism. Due to their good biocompatibility and various pharmacological activities, natural products are widely used in the fields of medicine, food, cosmetics, etc. Recently, some natural products with self-assembly capabilities have been discovered to form soft materials, natural product gels(NPG). Not exactly the same as the currently well-known gels(including synthetic low molecular mass gels, synthetic macromolecular gels, and natural macromolecular gels), NPG are natural(generally derived from traditional Chinese medicine) supramolecular gels. This makes NPG have good biological activity and responsiveness to external stimuli. Therefore, NPG have some inherent advantages in constructing biomedical materials and stimuli-responsive materials. In addition, studies of changes in the biological activity of different self-assembled NPGs can reveal the effects of self-assembly of natural products on biological activity. As such, the research and development of NPG is of great value. Here, we introduce the preparation, types, formation and application of NPG and their gelators, in an attempt to make people understand this emerging interdisciplinary research field.

Potassium which is abundant in the Earth’s crust and has similar physicochemical properties to lithium, has broad development prospects in the field of ion batteries. However, compared with lithium ion, the potassium-ion radius is relatively larger, leading to the lower migration rate of potassium ion in the material and the material is subjected to larger structural stress. This causes insufficient electrochemical performance advantages of the Potassium-ion battery. Therefore, developing cathode and anode material with stable structure and the capability for reversible reaction, and electrolyte which matches well with material has become a hot topic in the research of Potassium-ion battery. In this review, the latest research progress about cathode material, anode material and electrolyte of Potassium-ion battery at home and abroad are introduced, and we also prospect the future development tendency of Potassium-ion battery.