生物质基导电水凝胶的研究进展

随着石油危机日趋严重与“绿色发展”观念持续推进,生物质材料凭借其可再生、来源丰富、可生物降解、生物相容性好等诸多优势已成为众多领域的研究热点。生物质基导电水凝胶(Biomass-based conductive hydrogels,BCHs)是以生物质为原料制备的具有导电性质的水凝胶,具有生物质材料良好的生物相容性和生物降解性等本体性能,同时具有水凝胶的柔软特性和导电功能材料的电化学性能。本文首先根据导电原理的不同,将BCHs划分为离子导电、电子导电、离子-电子协同导电三个类型,接着介绍了基于BCHs的柔性可穿戴设备、超级电容器、发电机、智能机器人、组织工程等领域的最新应用研究,最后结合目前研究现状,对BCHs的应用前景和发展趋势进行展望。

天然动物皮的本体应用进展(续)

随着社会的进步、经济繁荣和科学技术的不断发展,天然生物质材料及其衍生物的应用领域得以不断拓展。作为典型生物质材料,天然动物皮具有资源丰富、廉价易得、可再生等特点,同时兼具良好的生物相容性、可降解性、低抗原性、可加工性以及物理机械性能等应用特性。按照化学的观点,动物皮的利用方式可以分为本体利用和水解产物利用两类。本文首先简要介绍了动物皮的结构、组成及应用分类。接着,综述了动物皮在功能皮革材料、生物医用材料、柔性电子传感材料领域的本体应用研究进展。最后,结合目前研究现状,对天然动物皮的本体应用前景和发展趋势进行了展望。

天然动物皮的本体应用进展

随着社会的进步、经济繁荣和科学技术的不断发展,天然生物质材料及其衍生物的应用领域得以不断拓展。作为典型生物质材料,天然动物皮具有资源丰富、廉价易得、可再生等特点,同时兼具良好的生物相容性、可降解性、低抗原性、可加工性以及物理机械性能等应用特性。按照化学的观点,动物皮的利用方式可以分为本体利用和水解产物利用两类。本文首先简要介绍了动物皮的结构、组成及应用分类。接着,综述了动物皮在功能皮革材料、生物医用材料、柔性电子传感材料领域的本体应用研究进展。最后,结合目前研究现状,对天然动物皮的本体应用前景和发展趋势进行了展望。

胶原化学改性及应用进展

胶原是动物组织中含量最高和分布最广的一类蛋白质,按发现顺序分为Ⅰ型胶原、Ⅱ型胶原、Ⅲ型胶原等,其中最常见的为Ⅰ型胶原。胶原具有良好的生物相容性、可降解性、低抗原性以及物理机械性能等,近年来被广泛应用于食品、生物材料、畜牧业、医美等多个领域。文章介绍了不同改性剂对胶原化学改性的特点,包括戊二醛、壳聚糖、京尼平、碳化二亚胺以及聚乙二醇等。同时,归纳了胶原在医疗美容、食品、柔性电子材料等领域的应用研究进展。最后,对胶原未来的推广应用进行了展望。

Interface-induced polymerization strategy for constructing titanium dioxide embedded carbon porous framework with enhanced chemical immobilization towards lithium polysulfides

The shuttle effect induced by soluble lithium polysulfides(LiPSs)is known as one of the crucial issues that limit the practical applications of lithium-sulfur(Li-S)batteries.Herein,a titanium dioxide nanoparticle embedded in nitrogen-doped porous carbon nanofiber(TiO_(2)@NCNF)composite is constructed via an interface-induced polymerization strategy to serve as an ideal sulfur host.Under the protection of the nanofiber walls,the uniformly dispersed TiO_(2) nanocrystalline can act as capturing centers to constantly immobilize LiPSs towards durable sulfur chemistry.Besides,the mesoporous microstructure in the fibrous framework endows the TiO_(2)@NCNF host with strong physical reservation for sulfur and LiPSs,sufficient pathways for electron/ion transfer,and excellent endurance for volume change.As expected,the sulfur-loaded TiO_(2)@NCNF composite electrode presents a fabulous rate performance and long cycle lifespan(capacity fading rate of 0.062%per cycle over 500 cycles)at 2.0 C.Furthermore,the assembled Li-S batteries harvest superb areal capacity and cycling stability even under high sulfur loading and lean electrolyte conditions.

In-situ constructed polymer/alloy composite with high ionic conductivity as an artificial solid electrolyte interphase to stabilize lithium metal anode

Lithium(Li)metal is regarded as the best anode material for lithium metal batteries(LMBs)due to its high theoretical specific capacity and low redox potential.However,the notorious dendrites growth and extreme instability of the solid electrolyte interphase(SEI)layers have severely retarded the commercialization process of LMBs.Herein,a double-layered polymer/alloy composite artificial SEI composed of a robust poly(1,3-dioxolane)(PDOL)protective layer,Sn and LiCl nanoparticles,denoted as PDOL@Sn-LiCl,is fabricated by the combination of in-situ substitution and polymerization processes on the surface of Li metal anode.The lithiophilic Sn-LiCl multiphase can supply plenty of Li-ion transport channels,contributing to the homogeneous nucleation and dense accumulation of Li metal.The mechanically tough PDOL layer can maintain the stability and compact structure of the inorganic layer in the long-term cycling,and suppress the volume fluctuation and dendrites formation of the Li metal anode.As a result,the symmetrical cell under the double-layered artificial SEI protection shows excellent cycling stability of 300 h at 5.0 mA·cm^(−2)for 1 mAh·cm^(−2).Notably,the Li||LiFePO_(4)full cell also exhibits enhanced capacity retention of 150.1 mAh·g^(−1)after 600 cycles at 1.0 C.Additionally,the protected Li foil can effectively resist the air and water corrosion,signifying the safe operation of Li metal in practical applications.This present finding proposed a different tactic to achieve safe and dendrite-free Li metal anodes with excellent cycling stability.

A dual-functional poly(vinyl alcohol)/poly(lithium acrylate)composite nanofiber separator for ionic shielding of polysulfides enables high-rate and ultra-stable Li-S batteries

Despite the high theoretical specific capacity,the main challenges of rechargeable lithium-sulfur(Li-S)batteries,including the unceasing shuttle of soluble lithium polysulfides(LiPSs)and severe Li corrosion,seriously hinder their commercial and practical applications.Herein,a bifunctional polyvinyl alcohol/poly(lithium acrylate)(C-PVA/PAA-Li)composite nanofiber separator is developed to address the main challenges in Li-S batteries by simultaneously allowing rapid lithium ion transport and ionic shielding of polysulfides.The C-PVA/PAA-Li composite nanofiber membrane is prepared via the facile electrospinning strategy,followed by thermal crosslinking and in-situ lithiation processes.Differing from the conventional Celgard-based coating methods accompanied by impaired lithium ion transport efficiency,the C-PVA/PAA-Li composite nanofiber membrane possesses well-developed porous structures and high ionic conductivity,thus synergistically reducing the charge transfer resistance and inhibiting the growth of lithium dendrites.The resulting Li-S batteries exhibit an ultra-low fading rate of 0.08%per cycle after 400 cycles at 0.2 C,and a capacity of 633 mAhg−1 at a high current density of 3 C.This study presents an inspiring and promising strategy to fabricate emerging dual-functional separators,which paves the pathway for the practical implementation of ultra-stable and reliable Li-S battery systems.

Carbon Fiber Supported Binary Metal Sulfide Catalysts with Multi-Dimensional Structures for Electrocatalytic Nitrogen Reduction Reactions Over a Wide pH Range

Green and environmentally friendly electrocatalytic nitrogen(N_(2))fixation to synthesize ammonia(NH3)is recognized as an effective method to replace the traditional Haber-Bosch process.However,the difficulties in N_(2) adsorption and fracture of hard N≡N bond still remain major challenges in electrocatalytic N_(2) reduction reactions(NRR).From the perspectives of enhancing N_(2) adsorption and providing more catalytic sites,two-dimensional(2D)FeS_(2) nanosheets and three-dimensional(3D)metal organic framework-derived ZnS embedded within N-doped carbon polyhedras are grown on the carbon cloth(CC)template in this work.Thus,a composite NRR catalyst with multi-dimensional structures,which is signed as FeS_(2)/ZnS-NC@CC,is obtained for using over a wide pH range.The uniform distribution of hollow ZnS-NC frameworks and FeS_(2) nanosheets on the surface of CC largely increase the N_(2) enrichment efficiency and offer more active sites,while the CC skeleton acts as an independent conductive substrate and S-doping helps promote the fracture of N≡N bond during the NRR reaction.As a result,the FeS_(2)/ZnS-NC@CC electrode achieves a high Faraday efficiency of 46.84%and NH3 yield of 58.52μg h^(−1) mg^(−1) at-0.5 V vs.Ag/AgCl in 0.1 M KOH.Furthermore,the FeS_(2)/ZnS-NC@CC electrode displays excellent NRR catalytic activity in acidic and neutral electrolytes as well,which outperforms most previously reported electrocatalysts including noble metals.Therefore,this work provides a new way for the design of multi-dimensional electrocatalysts with excellent electrocatalytic efficiency and stability for NRR applications.

Electroactive polymeric nanofibrous composite to drive in situ construction of lithiophilic SEI for stable lithium metal anodes

Uncontrolled lithium dendrite growth hinders the practical application of lithium metal batteries(LMBs).Herein,we report a novel Li^(+) flux distributor achieved by placing an electroactive polyvinylidene fluoride/polymethyl methacrylate(PVDF/PMMA)composite nanofiber interlayer on a current collector,inducing uniform lithium deposition to mitigate the dendrite problem.Specifically,the released PMMA reacts with Liþto form abundant C–O–Li bonds and generate in situ a stable lithiophilic PMMA-Li solid electrolyte interphase layer.Theoretical calculations reveal that polar C–F groups in the PVDF framework and lithiophilic PMMA-Li provide homo-dispersed Li^(+) migration pathways with low energy barriers.Consequently,uniform Li nucleation is achieved at the molecular level,resulting in ultrahigh cycling stability with dendrite-free Li deposition at 5 mA cm^(-2) and 5 mAh cm^(-2)for over 500 h.The PVDF/PMMA||Li||LiFePO_(4)(LFP)full cell presents an increased rate capacity of 110 mAh g^(-1) at 10 C.In addition,a soft-package battery demonstrates a high energy density of 289 Wh kg^(-1).This work provides a facile design for stable lithium metal anodes to promote the practical use of LMBs and other alkali metal batteries.

Effects of plants-associated microbiota on cultivation and quality of Chinese herbal medicines

Microbial resource influences the life activities of medicinal plants from several perspectives.Endophytes,rhizosphere microorganisms,and other environmental microorganisms play essential roles in medicinal plant growth and development,plant yield,and clinical efficacy.The microbiota can influence the biosynthesis of active compounds in medicinal plants by stimulating specific metabolic pathways.They induce host plants to improve their resistance to environmental stresses by accumulating secondary metabolites.Microorganisms can interact with their host plants to produce long-term,targeted selection results and improve their ability to adapt to the environment.Due to the interdependence and interaction between microorganisms and medicinal plants,Chinese herbal medicines(CHMs)quality is closely related to the associated microorganisms.This review summarizes the relationship between medicinal plants and their associated microorganisms,including their species,distribution,life activities,and metabolites.Microorganisms can aid in quality control,improve the efficacy of medicinal plants,and provide markers for identifying the origin and storage time of CHMs.Therefore,a comprehensive understanding of the relationship between microorganisms and medicinal plants will help to control the quality of CHMs from different perspectives.