静电纺丝法制备氧化物纳米纤维及其气敏特性

静电纺丝技术由于简单的装置和制备过程,以及所使用材料的多样和应用领域的广泛,被认为是制备纳米纤维材料最具发展潜力的方法.简述了静电纺丝技术和影响纺丝质量的相关因素;介绍了静电纺丝制备半导体氧化物纳米纤维的方法及纳米纤维在气体传感器领域的应用;比较了几种纳米纤维和纳米线纳米棒等气敏元件的敏感特性;最后分析了纳米纤维具有优...     

静电纺丝制备的ZrO2纳米纤维及其应用的研究进展

制备超细、高性能ZrO2纤维是实现其在催化、能源及环境等领域工程应用的关键。静电纺丝技术是一种近年来兴起的氧化物陶瓷纳米纤维制备新方法,能够制备直径较小、均一性高、连续性好的ZrO2纳米纤维,并且可通过控制前驱体纺丝液组成、静电纺丝工艺及热处理参数,对ZrO2纤维的组成、结构及性能进行调控。介绍了ZrO2纳米纤维制备、结构及性能方面的研究进展,并对经由原料组成、静电纺丝工艺及热处理条件调控的ZrO2纳米纤维结构、性能以及应用进行了综述和分析。     

静电纺丝法制备纳米结构金属氧化物的研究进展

静电纺丝法是在强电场作用下将聚合物溶液或熔体转化为微、纳米结构材料的一种简单有效的方法。通过共混或与传统的溶胶-凝胶法相结合,制备了实心、中空、多孔等多种纳米结构金属氧化物。系统地阐述了近年来利用静电纺丝法制备纳米结构金属氧化物的研究进展。     

静电纺丝法制备纳米结构金属氧化物的研究进展

静电纺丝法是在强电场作用下将聚合物溶液或熔体转化为微、纳米结构材料的一种简单有效的方法。通过共混或与传统的溶胶凝胶法相结合,制备了实心、中空、多孔等多种纳米结构金属氧化物。系统地阐述了近年来利用静电纺丝法制备纳米结构金属氧化物的研究进展。     

静电纺丝纳米纤维在吸附分离领域的应用进展

静电纺丝技术作为一种简单有效的制备纳米纤维的方法,制备的纳米纤维具有巨大的比表面积,而且采用该技术制备纳米纤维具有操作简单、易于控制、成本低廉等特点,已经在生物医学领域、国防领域、吸附分离领域等取得了一系列应用进展。本文首先对静电纺丝技术做了概述;其次,对其制备原理、影响因素及应用优势等做了简要的说明;然后重点综述了静电纺丝制得的纳米纤维在吸附分离领域的应用进展,总结了静电纺丝纳米纤维存在的问题并对其在吸附分离领域的应用趋势做出了展望。     

静电纺丝制备多孔纳米纤维的研究进展

静电纺丝是一种能够制备连续纳米纤维的简单、方便、高效的方法,在组织工程、药物缓释和催化剂负载等领域应用广泛,近年来该方法制备的表面或内部具有多孔结构的纳米纤维因具有超高的比表面积而备受关注。综述了电纺多孔纳米纤维的制备方法和成孔机理,详细讨论了液相分离致孔和固相分离致孔的研究现状和未来发展方向。从纺丝液溶剂性质展开,结合混溶、控温、控湿等实验条件,分析了射流固化速率和溶剂挥发速率的相互作用关系,并提出多手段共用制备孔结构可控的多孔纳米纤维的方法。     

静电纺丝制备纳米纤维及其工业化研究进展

针对静电纺丝技术从实验室走向工业化还存在产率低的问题,重点分析了为提高生产效率而采用的多针头纺丝和无针头纺丝等批量化生产方法,简述了静电纺丝的基本原理和实施方法,介绍了静电纺丝制备聚合物纤维、无机物纤维、同轴及中空纤维的情况和特点。随着对静电纺丝方法、设备、工艺和材料研究的深入,通过对高压静电场分布的控制采用多喷头组合方式和无针滚筒方式将成为产业化制备纳米纤维的有效手段。通过控制高压电场分布利用提高效率后的单孔纺丝方法制备出了长、宽、厚分别为1000mm、350mm、1.28mm的芳纶1313纳米纤维布。最后对静电纺丝工业化规模制备纳米纤维材料进行了展望。     

制备三维结构静电纺丝纳米纤维组织支架的方法

三维结构纳米纤维构件具有内部比表面积大、孔径大、孔互联互通、组成和结构可控、整体材料结构具有一定支撑性的优点,因此具有广阔的应用前景,特别是在组织支架方面的应用成为人们关注的焦点。静电纺丝制备的纳米纤维由于具有直径超细、表面积大、多孔、高孔隙率、与骨架细胞外基质的结构极为相似等特点,迅速发展成为一种前景非常广阔的组织工程支架材料,同时通过一定的方法可以得到三维结构的静电纺丝纳米纤维组织支架。综述了国内外通过静电纺丝工艺来制备三维结构纳米纤维组织支架的方法,包括连续不间断纺丝法、多层交替纺丝法、纺丝设备改进法、后处理法、辅助收集法、添加致孔剂法、自组装法等。     

基于静电纺丝制备中空纳米纤维的研究进展

中空纳米纤维具有独特的中空结构和较大的比表面积，在吸附、催化、电化学、医药等领域具有广阔的应用前景。静电纺丝技术是制备中空纳米纤维的有效手段。随着静电纺丝工艺的不断成熟，利用静电纺丝大规模制备中空纳米纤维提上了日程。首先详细介绍了基于静电纺丝技术制备中空纳米纤维的原理和方法，探讨了现阶段基于静电纺丝技术大规模制备中空纳米纤维存在的问题以及研究现状，总结了中空纳米纤维的应用进展，最后指出了中空纳米纤维的发展方向，为推动中空纳米纤维的大规模制备及应用奠定基础。     

静电纺丝技术及其相关产品的应用

静电纺丝技术是一种新型高效的纳米材料制备方法。简述了静电纺丝装置、接收板、及静电纺丝技制备成纳米材料的基本原理,对处于发展和完善中的电纺丝过程进行了总结,并介绍了利用电纺丝技术制得的纳米产品及其应用。     

Electrospun porous nanofibers for electrochemical energy storage

The demand for energy storage systems is rising due to the rapid development of electric transportation vehicles, and this demand is stimulating research on the next generation of high-performance, high-density energy storage devices. In this work, nanomaterials with excellent electrochemical properties are of particular significance. This review summarizes a variety of methods based on electrospinning techniques for the preparation of porous nanofibers with controllable morphologies. An emphasis is placed on methods involving polymer templates and polymer blend templates, hard templates, and on solvent-induced, nonsolvent-induced or activation methods. As a simple and cost-effective method for preparing one-dimensional nanomaterials, the electrospinning technique is of special significance in the energy storage field, because the as-prepared porous nanofibers exhibit large specific surface areas and interconnected micro-/meso-/macroporous structures. Both of these features enable greater energy storage. Furthermore, this review presents several suggestions for meeting the challenges involved in the preparation and industrial application of electrospun porous nanofibers for advanced energy storage systems.     

用于光催化的金属氧化物多孔材料的研究进展

金属氧化物材料的多孔化制备受到越来越多的关注,由于其大的比表面积、较多的活性位点、便于物质传输的双连续结构等特点,在环境保护、能源、精细化工等各个领域得到广泛的应用。本文综述了几种多孔金属氧化物材料(二氧化钛、铋系半导体、氧化锌、氧化亚铜等)在光催化领域的最新研究进展,分析了多孔氧化物的制备工艺、生长机理、光催化性能,最后对多孔氧化物材料的制备、改性及光催化性能进行了总结,并对未来的发展方向进行了展望。     

静电纺丝制备PVDF多孔纳米纤维及其在吸油中的应用

采用静电纺丝和PEO模板相结合加工制备了具有超疏水性能的PVDF多孔纳米纤维.通过扫描电镜(SEM)观察所制备的PVDF纤维具有均匀微纳米二级孔道显微结构,测得该多孔纳米纤维表面接触角高达158°,呈现良好的超疏水特性.研究发现,将PVDF多孔纳米纤维作为溢油吸附材料具有良好的吸油效能,其对润滑油、柴油、植物油和汽油的...     

Nanoporous polymeric materials: A new class of materials with enhanced properties

Nanoporous polymeric materials are porous materials with pore sizes in the nanometer range (i.e., below 200 nm), processed as bulk or film materials, and from a wide set of polymers. Over the last several years, research and development on these novel materials have progressed significantly, because it is believed that the reduction of the pore size to the nanometer range could strongly influence some of the properties of porous polymers, providing unexpected and improved properties compared to conventional porous and microporous polymers and non-porous solids.In this review, the key properties of these nanoporous polymeric materials (mechanical, thermal, dielectric, optical, filtration, sensing, etc.) are analyzed. The experimental and theoretical results obtained up to date related to the structure–property relations are presented. In several sections, in order to present a more compressive approach, the trends obtained for nanoporous polymers are compared to those for metallic and ceramic nanoporous systems. Moreover, some specific characteristics of these materials, such as the consequences of the confinement of both gas and solid phases, are described. Likewise, the main production methods are briefly described. Finally, some of the potential applications of these materials are also discussed in this paper.     

Screen-printed Tin-doped indium oxide (ITO) films for NH3 gas sensing

Gas sensors using metal oxides have several advantageous features such as simplicity in device structure and low cost fabrication. In this work, Tin-doped indium oxide (ITO) films were prepared by the screen printing technique onto glass substrates. The granular and porous structure of screen-printed ITO are suitable for its use in gas sensing devices. The resistance of the ITO films was found to be strongly dependent on working temperatures and the nature and concentration of the ambient gases. We show that screen-printed ITO films have good sensing properties toward NH₃ vapours. The observed behaviors are explained basing on the oxidizing or the reducer nature of the gaseous species that react on the surface of the heated semi-conducting oxide.     

Preparation and properties of nanofiber-coated composite membranes as battery separators via electrospinning

An electrospun nanofiber-coated Celgard^® 2400 polypropylene microporous battery separator was prepared using polyvinylidene fluoride (PVDF) and polyvinylidene fluoride-co-chlorotrifluoroethylene (PVDF-co-CTFE). The coating of PVDF and PVDF-co-CTFE nanofibers was carried out using single nozzle and nozzle-less electrospinning methods. The nanofiber coating prepared by the nozzle-less electrospinning method was found to have better adhesion to the microporous separator membrane than the nanofiber coating prepared by single nozzle electrospinning. The PVDF and PVDF-co-CTFE nanofiber coatings increased the electrolyte uptake capacity in a secondary lithium-ion battery, with PVDF-co-CTFE co-polymer nanofiber-coated microporous membrane showing higher electrolyte uptake capacity than PVDF homopolymer-coated microporous membrane. In addition, the PVDF and PVDF-co-CTFE nanofiber coatings improved the adhesion of the porous microporous membrane to a battery electrode. It was also found that nanofiber coatings prepared by the nozzle-less electrospinning method have better adhesion properties and higher electrolyte uptake capacity than those by single nozzle electrospinning.     

Electrospinning of PLGA/gelatin randomly-oriented and aligned nanofibers as potential scaffold in tissue engineering

Electrospinning technique can be used to produce the three-dimensional nanofibrous scaffold similar to natural extracellular matrix, which satisfies particular requirements of tissue engineering scaffold. Randomly-oriented and aligned poly(lactic-co-glycolic acid) (PLGA) and PLGA/gelatin biocomposite scaffolds were successfully produced by electrospinning in the present study. The resulting nanofibrous scaffolds exhibited smooth surface and high porous structure. Blending PLGA with gelatin enhanced the hydrophilicity but decreased the average fiber diameter and the mechanical properties of the scaffolds under the same electrospinning condition. The cell culture results showed that the elongation of the osteoblast on the aligned nanofibrous scaffold was parallel to the fiber arrangement and the cell number was similar to that of randomly-oriented scaffold, indicating that the aligned nanofibrous scaffold provide a beneficial approach for the bone regeneration.     

热透波材料技术研究进展

热透波材料技术是高超声速飞行器实现通讯与精确导航的关键技术,文章从热透波材料体系、热透波材料热电行为和高温电性能测试技术等方面对热透波材料及其相关技术的发展现状进行了简要介绍。在材料体系方面,石英陶瓷及二氧化硅基复合材料是目前应用的主要材料品种,多孔氮化物陶瓷及陶瓷基复合材料是未来发展的重要方向。在热电行为研究方面,对典型氧化物、氮化物、氮氧化物材料热电行为规律及杂质离子对材料热电行为的影响等方面的研究获得重要进展,并获得试验验证。在高温电性能测试方面,近年来突破了1 600℃高温宽频测试关键技术,并获得了氧化硅熔融态介电性能实测数据,国外和国内已实现8 MW/m2热透波实时测试。     

氧化物热电材料研究进展

氧化物基热电材料具有高温稳定性、抗氧化性和安全长效等优点而受到人们的广泛关注, 但其应用受到了热电性能的限制。本文详细介绍了几种典型氧化物热电体系, 如层状钴基氧化物、钙钛矿结构化合物、透明导电氧化物和一些新型氧化物热电材料的研究进展。从能带结构和微观形貌两方面入手进行调节, 以达到热电材料热学性能和电学性能的协调统一。分析了氧化物热电材料研究中的主要问题, 并对未来的发展提出了一些新的思路。