Proton exchange membranes are widely used in energy storage and conversion technologies such as fuel cells, redox flow batteries, and water electrolysis, which are key materials urgently needed under the “dual carbon” goal. Perfluorosulfonic acid membranes show high proton conductivity and mechanical properties, which are currently the most widely used proton exchange membranes materials. However, these membranes suffer from the following disadvantages, such as greatly decreased proton conductivity at low humidity conditions, low glass transition temperature, and complex synthesis process. In the past decades, efforts have been devoted to the development of various alternative materials, such as polyether ether ketone, polyphenylene oxide, polysulfone and polyimide. However, the main chains of these polymers usually contain heteroatoms. Upon working in a complex practical condition for a long time, the heteroatom position is prone to break, which reduces the chemical stability of these materials. In contrast, the all-carbon backbone aromatic polymers have excellent chemical stability, thermal stability, and mechanical properties, and are a class of potential alternative materials that have attracted extensive attention in recent years. In this review paper, we summarize the recent research progress of all-carbon backbone aromatic polymers, focusing on the synthesis strategies, structure-performance relationships, as well as the applications of these polymers in proton exchange membranes.

Proteins play critical roles in various biological processes and biomedical researches. A significant task of such biochemical studies is to obtain protein samples of high homogeneity with respect to their atomic compositions. Chemical protein synthesis offers a much more robust and effective strategy over recombinant expression technology for accessing proteins that are precisely modified or even artificially designed. However, some important proteins that can be used as drug targets (such as human interleukin-2, K⁺ channel protein Kir5.1, etc.) suffer from limited solubility of peptide segments during the journey of protein synthesis. Such hydrophobic peptides pose difficulty for subsequent purification, characterization, chemical ligation and other operations. The main factors for these problems may be that the peptide segments are prone to self-assemble into secondary structures through hydrophobic interactions, hydrogen bond or other interaction modes, thus reducing the solubility. Addition of solubilizing tags is recognized as one of the effective methods to overcome such obstacles. In this review, strategies of attaching solubilizing tags to the main chain, side chain and backbone of peptides are introduced. Membrane protein FCER1G, co-chaperone protein GroES and other proteins are selected as examples to describe the applications of the solubilizing tags. Moreover, the future of solubilizing tags strategy is discussed and prospected.

Vanadium redox flow battery (VRB) is the most promising large-scale energy storage system due to its flexibility, high efficiency and being pollution-free, which has attracted wide attention from researchers. The separator is a key component of VRB, which plays a role in isolating vanadium ions from cross-penetration and providing proton transmembrane transfer channels. Nafion membranes produced by DuPont are the most commonly used ion exchange membranes for VRB due to their good chemical stability and high proton conductivity. However, they have problems such as poor vanadium resistance and high cost. Therefore, the key point of current research is to control the ion exchange capacity of the Nafion membrane reasonably, improve the vanadium resistance capacity of the Nafion membrane while retaining the excellent performance of the Nafion membrane through modification methods, and reduce the cost of the Nafion membrane. In this paper, the working principle of VRB and the performance characteristics of Nafion membrane are discussed. The current trend and future direction of Nafion membrane modification methods are also discussed in detail. This is of great significance for understanding the structure-activity relationship between modified Nafion membrane structure and battery performance, and guiding the future modification and design of Nafion membrane.

Directed self-assembly (DSA) of block copolymer (BCP) has been identified as the potential strategy for the next-generation semiconductor manufacturing. The typical representative of the first generation (G1) of block copolymer for nanolithography is polystyrene-block-polymethylmethacrylate (PS-b-PMMA). DSA of PS-b-PMMA enables limited half pitch (0.5L₀) of 11 nm due to the low Flory-Huggins interaction parameter (χ). The second generation (G2) of BCP is developed with the feature of high χ. Solvent anneal or top-coat is employed for the G2 BCP to form the perpendicular lamellae orientation. Towards industry friendly thermal anneal, high χ BCP with equal surface energy (γ) is reported as the third generation (G3) BCP. Recently, based on Materials Genome Initiative (MGI) concept, optimized design of block copolymers with covarying properties (G4) for nanolithography is presented to meet specific application criteria. G4 BCP achieves not only high χ and equal γ, but also high throughput synthesis, 4~10 nm half pitch patterns, and controlled segregation strength. This review focuses on the advanced design of G3 and G4 BCP for nanolithography. Moreover, the challenges and opportunities are discussed for the further development of DSA of BCP.

One of the most promising candidates for large-scale energy storage applications is the solid-state sodium ion battery, which replaces conventional organic liquid electrolytes with solid electrolytes and has the advantages of high safety, high energy density, and extended cycle life. Among many solid electrolyte materials, Poly(ethylene oxide) (PEO)-based polymer solid electrolytes are considered promising solid electrolyte materials because of their high safety, easy manufacturing, low cost, high energy density, favorable electrochemical stability, and excellent solubility in sodium salts. However, the high crystallinity of the ethylene oxide (EO) chain segment results in low ionic conductivity at room temperature, which is unable to meet the requirements of practical application. To overcome the aforementioned limitations, researchers have used a variety of strategies to lessen the crystallinity of PEO-based polymer electrolyte and hence increase its ionic conductivity. Common techniques include polymer block copolymerization, blending, crosslinking, adding plasticizers, and adding inorganic fillers. In the review, the physical and chemical properties, preparation methods, and modification techniques of PEO-based polymer electrolytes are evaluated, and the most recent advancements on PEO-based polymer electrolytes are reviewed.

Fuel cell, a kind of energy conversion device that can directly convert chemical energy into electric energy, is a new and an important energy technology during China’s 14th Five-Year Plan. In recent years, the fuel cell technology has undergone iterative upgrading, which effectively promotes the transition of hydrogen energy industry from mode-exploration to multiple demonstration, and helps the high-quality development of the new energy. Cathodic oxygen reduction reaction (ORR) is one of the basic and core reactions of fuel cells, but its slow kinetic process restricts the large-scale application of fuel cells. Although metal Pt-based catalysts have high catalytic activity and can improve the reaction rate of ORR, they are not conducive to wide commercial use because of their scarcity, high cost and poor durability. The development of non-Pt-based ORR catalysts is of great practical significance to promote the development of fuel cells. Porous Organic Polymers (POPs) are an important branch of porous materials. Due to their controllable composition and diverse structure, heteroatoms and metal species can be incorporated into the skeleton to enhance the overall catalytic activity of materials. As ideal candidate materials for electrocatalysts with high-efficiency, POPs have attracted wide attention in promoting the slow kinetics of ORR. In this paper, the research progress in the synthesis strategy, composition, morphology, structure regulation and electrocatalytic performance of POPs-derived carbon-based ORR electrocatalysts in recent years are emphatically introduced. The challenges faced by POPs-derived carbon-based ORR electrocatalysts at present are discussed, and their future development directions are summarized.

With the rapid development of nanotechnology, nanomaterials have been widely used in the field of cancer treatment. It is well known that autophagy, as a process that maintains cellular homeostasis, plays a dual role in promoting survival and death in cancer development. The level of autophagy in cancer cells is significantly higher than that in normal cells, resulting in various treatment strategies being ineffective. Synergistic treatment of cancer by perturbing autophagy has become a viable option, but traditional autophagy perturbing agents such as chloroquine may lead to certain other side effects. In addition, it has been demonstrated that nanomaterials can be used as a novel autophagy perturber, but the mechanism by which nanomaterials interfere with autophagy needs to be more deeply understood. This review provides an overview of the dual relationship between cancer and autophagy, and highlights the mechanisms by which various nanomaterials induce cancer cell death or apoptosis by perturbing autophagy, or enhance the sensitivity of cancer cells to conventional cancer therapy by perturbing autophagy, and the mechanisms by which they modulate autophagy.

Double Network Hydrogels are polymer materials composed of two interpenetrating or semi-penetrating three-dimensional networks, and their unique contrast interpenetrating network structure and adjustable network crosslinking method overcome the obstacles in mechanical properties of single-network hydrogels, and are widely used in tissue engineering, intelligent sensors, ion adsorption and other fields with their good mechanical, anti-swelling, self-healing and other mechanical properties. However, the existing technologies suffer from numerous synthesis steps, complicated preparation conditions and the use of toxic and harmful chemical cross-linking, which limit the mass production of double network hydrogels for applications. Therefore, in recent years, the modification of double network hydrogels has received more and more attention, and researchers have carried out a series of structural modification studies mainly around how to improve the mechanical properties of double network hydrogels, aiming to broaden their application in various fields. In this paper, the types of double network hydrogels are reviewed, and the preparation methods, structures and unique properties of different hydrogels are introduced in detail. The research on modification to improve mechanical properties, anti-swelling performance and self-healing properties is analyzed, aiming to break through the current limitations of double network hydrogels and provide ideas and directions for their future development.

Electrospun fibrous sponge is a fluffy three-dimensional (3D) material based on one-dimensional fibers. The increase of dimension makes this material have many more prominent advantages than traditional electrospun films, so it has shown great application potential in various fields. With the in-depth study of the three-dimensional structure of electrospinning, it has become a current challenge to obtain stable fibrous sponges directly by electrospinning and improve their performance. In this paper, various new strategies for preparing fibrous sponges by direct electrospinning in recent years are reviewed in detail. Firstly, the mechanism, characteristics and representative research results of different methods are analyzed and summarized. Then the application status of this material in the fields of tissue engineering, environmental governance, safety protection and intelligent equipment is introduced. Finally, the future development trend of electrospinning fibrous sponge is prospected.

Aqueous zinc-ion batteries (AZIBs) have great advantages in terms of safety, low cost, high theoretical capacity and element abundance, which shows great potential in large-scale energy storage applications. The development of high-performance AZIBs has become a widely interesting topic recently. Although much progress has been made in AZIBs, the low energy density, poor ionic dynamics and short cycling life limit the commercialization of AZIBs. This review summarizes the challenges, recent progress and corresponding strategies for the development of cathodes, anodes, electrolytes, and energy storage mechanisms of AZIBs. It provides useful guidance for researchers in the battery area to design and develop high performance AZIBs.