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Cellulose, as the most abundant natural polymer on Earth, has long captured researchers' attention due to its high strength and modulus. Nevertheless, transferring its exceptional mechanical properties to macroscopic 2D and 3D materials poses numerous challenges. This review provides an overview of the research progress in the development of strong cellulose-based materials using both the "bottom-up" and "top-down" approaches. In the "bottom-up" strategy, various forms of regenerated cellulose-based materials and nanocellulose-based high-strength materials assembled by different methods are discussed. Under the "top-down" approach, the focus is on the development of reinforced cellulose-based materials derived from wood, bamboo, rattan and straw. Furthermore, a brief overview of the potential applications fordifferent types of strong cellulose-based materials is given, followed by a concise discussion on future directions. [ABSTRACT FROM AUTHOR]

The predominant adhesives currently utilized in the wood sector are sourced from petroleum. However, it is crucial to acknowledge that fossil resources possess a limited supply, and their extraction procedures can lead to adverse effects on the ecosystem. Renewable biomass resources have important application prospects in wood adhesives. This paper reviews the recent research progress on utilizing biomass to replace or modify conventional petroleum-based adhesives, focusing on the application of tannin, lignin, protein, starch, and cellulose in urea–formaldehyde (UF), melamine, phenol–formaldehyde (PF), epoxy (EP), and polyurethane (PU) resin adhesives. The symbiosis of renewable biomass with conventional petroleum-based adhesives portends substantial advancements for the wood adhesive industry. This review evaluates the substitution capacity and modification effect of biomass, discusses its application prospects in the wood-based panel industry, and predicts the future direction of biomass in wood adhesives, providing new inspirations for the development of novel green adhesives. [ABSTRACT FROM AUTHOR]

Biomass-derived heteroatom doped porous carbon is a hot electrode material for supercapacitors. Herein, nitrogen and oxygen co-doped porous carbon sheets are prepared by one-step carbonization-activation of hybrids of soybean protein isolate and zinc chloride (ZnCl2). The effect of the mass ratio between the activator and carbon precursor on the microstructure as well as the electrochemical performance of the materials is investigated. The activated samples show enhanced specific surface area, preferably up to 1034.33 m2 g−1, which is dominated by micropores and mesopores. More interestingly, ZnCl2 incorporation can improve the doping rate of nitrogen and oxygen elements from 4.5 at% to 6.37 at%, and 12.89 at% to 13.58 at%, respectively. Ultimately, the porous carbon sheets exhibit good capacitive performance in 6 M KOH electrolyte, and the specific capacitance could reach 210.47 F g−1 in a three-electrode system. In a two-electrode system, a capacitance retention of 93.02% can be achieved after 10 000 cycles at 20 A g−1. In addition, the optimized sample shows a maximum energy density of 16.27 W h kg−1 and a maximum power density of 8.44 kW kg−1. This work indicates that the soybean protein-derived porous carbon sheets are promising electrode materials for supercapacitors. [ABSTRACT FROM AUTHOR]

La–Mn bimetal oxide nanofibers, used as an adsorbent for the defluoridation of water, were synthesized by an electrospinning and heat treatment technology. The La–Mn bimetal oxide nanofiber adsorbent with a specific surface area of 35.064 m2 g−1 displayed a good defluoridation performance. Both the adsorption kinetics and equilibrium for fluoride (F−) uptake onto La–Mn bimetal oxide nanofibers were investigated. The kinetic studies established that the adsorption attained equilibrium at about 90 min, and the PSO kinetic model was ideal for the kinetic data under 20 and 50 mg L−1. The Langmuir maximum F− uptake was computed to be 189.39 mg g−1 at 308 K and pH 3. A thermodynamic study affirmed a feasible, endothermic, spontaneous and entropy driven process of F− adsorption towards La–Mn bimetal oxide nanofibers at the studied temperature range. Except for the competitive adsorption of PO43− and F−, the presence of NO3−, CO32−, Cl− and SO42− had little effect on fluoride removal. The La–Mn bimetal oxide adsorbent exhibited a good reusability. [ABSTRACT FROM AUTHOR]

Flax fibers, with abundant resources and a low cost, are an excellent precursor of carbon fibers for supercapacitors. At present, they are very attractive for designing electrodes with high electrochemical performance via a simple and green way. Hence, we systemically control the specific surface area and pore structure of flax-based carbon fibers by impregnating them with zinc chloride (ZnCl2) solution. The results show that the dehydration and expansion effects of ZnCl2 affect the microstructure, which is directly related to the specific capacitance. After activation, the optimized electrode exhibited the highest specific capacitance of 105 F g−1 at a current density of 1 A g−1, which has been improved by more than 10 times compared to that of pure-flax based carbon fibers. Moreover, they also show an excellent cycling stability of 98.7% after 10 000 cycles, even at a high current density of 10 A g−1. These results further demonstrate that flax-based electrodes have potential to be applied to some relevant energy storage applications in the future. [ABSTRACT FROM AUTHOR]

The oxygen evolution reaction (OER) plays a crucial role in sustainable energy conversion and storage including water splitting, fuel cells, and metal–air batteries. The design and exploration of earth-abundant OER electrocatalysts with low cost, high-performance, and durability are of paramount importance. Nanoarray catalysts constructed on free-standing carbon substrates have drawn significant attention owing to their high conductivity, fascinating nanostructures, and abundant active sites. This review presents recent progress toward advanced self-supported catalysts for the OER. We have systematically overviewed diverse synthetic approaches for the preparation of self-supported electrocatalysts with selected examples of metal oxides, metal hydroxides/oxyhydroxides, metal phosphides, metal sulfides, metal selenides, and metal–organic frameworks (MOFs) and their derivatives. State-of-the-art strategies to improve OER catalytic activity and stability of self-supported catalysts are provided including interface and defect engineering as well as heteroatom-doping. Finally, an overview of current challenges and future prospects for developing more promising carbon substrate supported nanoarray catalysts is provided. [ABSTRACT FROM AUTHOR]

To enhance the electrochemical properties of LiNi1/3Co1/3Mn1/3O2 (NCM) materials for lithium-ion batteries (LIBs), TiO2-coated Mg–Zr co-doped NCM cathode materials (MZT-NCM) were fabricated via a two-step solid-state method using Mg(OH)2, Zr(OH)4 and Ti(OH)3 as Mg, Zr and Ti sources, respectively. The electrochemical characteristics were assessed by the hybrid pulse power characteristic (HPPC) test, galvanostatic charge–discharge, EIS and CV test. Compared with NCM, the electrochemical properties of MZT-NCM as a cathode material in a pouch-cell were enhanced, especially high power performance and the stability of long cycle life. The MZT-NCM exhibits an excellent power performance of 2051 W, compared to that of the NCM, which only achieves 1736 W at 50% state of charge (SOC). Furthermore, the MZT-NCM samples deliver an outstanding capacity retention rate of 91.10% after 7000 cycles at 3C, which is nearly 10% higher than that of NCM. The modification strategy has a positive effect on the electrochemical characteristics of NCM cathode materials, which is expected to provide meaningful guidance for developing high power and long cycle life LIBs. [ABSTRACT FROM AUTHOR]

A bio-inspired cellulose paper–poly(amidoxime) composite hydrogel is explored via UV-polymerization. This hydrogel has a highly efficient uranium capture capacity of up to 6.21 mg g−1 for WU/Wdry gel and 12.9 mg g−1 for WU/Wpoly(amidoxime) in seawater for 6 weeks, due to its enhanced hydrophilicity, good hydraulic/ionic conductivity and broad-spectrum antibacterial performance. [ABSTRACT FROM AUTHOR]

We present a new strategy for the fabrication of nanoporous polymer films assembled using strong polyelectrolyte pairs in ionic liquid aqueous solutions. These nanoporous films show good anti-reflection properties. [ABSTRACT FROM AUTHOR]

Stimuli-responsive bio-based polymeric systems are gaining considerable attention as intelligent versatile tools that show great potential in various fields. In this review, an overview is given of recent developments of stimuli-responsive bio-based polymeric systems. The characteristics of bio-based polymers in different applications are discussed and the superiority of these advanced stimuli-responsive bio-based polymeric systems is highlighted. Furthermore, several emerging applications of these systems including intelligent drug delivery, responsive food packaging and smart water treatment are discussed and the section of intelligent drug delivery is emphasized in detail. Finally, the respective prospects and limitations inherent to these systems are addressed. [ABSTRACT FROM AUTHOR]

Single electrospun copolyimide nanofiber and aligned co-PI nanofiber belts with high strength and high modulus were prepared from copolyamic acid containing pyrimidine units. The chemical structures of copolyamic acid and copolyimide were characterized by 1H-NMR and FT-IR spectra. The morphology of the electrospun nanofibers was investigated by SEM and AFM. The mechanical properties of the single electrospun nanofiber and aligned nanofiber belts were measured by the single fiber micro-tensile test and the uniaxial tensile test, respectively. The thermal properties of the co-PI nanofiber belts were evaluated on TGA and DMA machines. The results indicated that the incorporation of rigid pyrimidine units, the molar ratio of pyrimidine/4,4′-oxydianiline and the imidization temperature played an important role in the mechanical properties of electrospun copolyamic acid and copolyimide nanofibers while the thermal properties were influenced by the molar ratio of rigid and soft components in the copolyimide main chains. [ABSTRACT FROM AUTHOR]

Mechanically strong electrospun nanofibers at high temperature are highly desired in the aerospace industry, high temperature filtration and fire protection clothing. In the present work, highly tough poly(imide-co-benzoxazole) (PI-co-PBO) nanofiber belts with excellent thermal stability, mechanical properties and thermomechanical properties were produced from the highly viscous methoxy-containing polyamic acid (MeO-PAA) solution by electrospinning followed by thermal rearrangement. The chemical structures of the polymer nanofibers and the corresponding thermal rearrangement were confirmed by 1H-NMR, FT-IR and TGA. The mechanical properties and thermomechanical properties were characterized by a tensile test and thermomechanical analysis (TMA). The aligned nanofiber belts heat-treated at 450 °C (ANF-450) had the highest tensile strength of 559 MPa, a modulus of 11.2 GPa and a toughness of 12.0 J g−1, respectively, which were much higher than those of the pure PBO films made by thermal rearrangement. The TMA test showed that the ANF-450 exhibited a high tensile strength retention of 90% and a modulus retention of 94% at a high temperature of 200 °C. These excellent thermomechanical properties make electrospun PI-co-PBO nanofibers promising candidates in high temperature areas. [ABSTRACT FROM AUTHOR]

As a unique structural form, helical structures have a wide range of application prospects. In the field of biology, helical structures are essential for the function of biological macromolecules such as proteins, so the study of helical structures can help to deeply understand life phenomena and develop new biotechnology. In materials science, helical structures can give rise to special physical and chemical properties, such as in the case of spiral nanotubes, helical fibers, etc. , which are expected to be used in energy, environment, medical and other fields. The helical structure also has unique charm and application value in the fields of aesthetics and architecture. In addition, helical fibers have attracted a lot of attention because of their tendrils' vascular geometry and indispensable structural properties. In this paper, the development of helical fibers is briefly reviewed from the aspects of mechanism, synthesis process and application. Due to their good chemical and physical properties, helical fibers have a good application prospect in many fields. Potential problems and future opportunities for helical fibers are also presented for future studies.

In 2022 10% of the world's population was aged 65+, and by 2100 this segment is expected to hit 25%. These demographic changes place considerable pressure over healthcare systems worldwide, which results in an urgent need for accurate, inexpensive and non-invasive ways to treat cancers, a family of diseases correlated with age. Among the therapeutic tools that gained important attention in this context, photodynamic therapies (PDT), which use photosensitizers to produce cytotoxic substances for selectively destroying tumor cells and tissues under light irradiation, profile as important players for next-generation nanomedicine. However, the development of clinical applications is progressing at slow pace, due to still pending bottlenecks, such as the limited tissue penetration of the excitation light, and insufficient targeting performance of the therapeutic probes to fully avoid damage to normal cells and tissues. The penetration depth of long-wavelength near infrared (NIR) light is significantly higher than that of short-wavelength UV and visible light, and thus NIR light in the second window (NIR-II) is acknowledged as the preferred phototherapeutic means for eliminating deep-seated tumors, given the higher maximum permissible exposure, reduced phototoxicity and low autofluorescence, among others. Upon collective multidisciplinary efforts of experts in materials science, medicine and biology, multifunctional NIR-II inorganic or organic photosensitizers have been widely developed. This review overviews the current state-of-the art on NIR-II-activated photosensitizers and their applications for the treatment of deep tumors. We also place focus on recent efforts that combine NIR-II activated PDT with other complementary therapeutic routes such as photothermal therapy, chemotherapy, immunotherapy, starvation, and gas therapies. Finally, we discuss still pending challenges and problems of PDT and provide a series of perspectives that we find useful for further extending the state-of-the art on NIR-II-triggered PDT.