静电纺多级孔材料制备研究进展

包含纤维间与纤维内多孔结构的静电纺多级孔材料,具有大的比表面积和独特的性能,在多个领域具有潜在的应用价值。本文综述了用静电纺丝法制备多级孔纳米纤维毡的方法,包括有机聚合物纤维与陶瓷纤维。由溶剂挥发等多种因素引致的相分离是有机聚合物纤维生成多孔结构的主要机理,而模板法则是制备多孔陶瓷纤维的主要手段。多级孔结构的形成增大了材料的比表面积,增强了材料的疏水性,赋予了静电纺纤维毡材料独特的性能。     

静电纺丝技术制备催化剂的研究进展

综述了静电纺丝技术制备纳米纤维的3种方法——同轴电纺法、溶胶转化法和功能复合法,分析了3种制备催化剂方法的优缺点,并对静电纺丝技术未来的发展方向进行了展望。     

电纺纳米纤维的研究及应用

静电纺丝(电纺)技术是一种制备直径为数10 nm到数100nm纳米纤维的有效方法.本文介绍了静电纺丝中原料聚合物的类型、纺丝条件和纺丝技术等方面的研究成果,电纺纳米纤维和产品的特性及其应用.     

天然高分子静电纺纳米纤维的研究进展

介绍了静电纺丝的原理及利用静电纺丝方法制备天然高分子纳米纤维的最新研究进展,主要介绍了海藻酸钠、天然纤维素、透明质酸、明胶、胶原蛋白、甲壳素及其衍生物等几种主要的天然高分子静电纺纤维的研究进展,并指出它们在生物医学领域的重要应用。     

静电纺丝技术在制备锂离子电池电极的应用

锂离子二次电池由于具有容量大、寿命长、无环境污染、使用安全等优点,已广泛应用于移动电话、笔记本电脑等便携式电器中。静电纺丝技术是一种超细纤维的制备方法,本文对电纺装置进行了介绍,还介绍了锂离子电池电极材料的种类、用电纺方法制备的不同电极材料的性能,并对用电纺技术制备电极材料的发展进行了展望。     

酚醛基活性炭纤维静电纺丝制备的研究进展

酚醛基活性炭纤维(PACF)是由酚醛纤维经固化、炭化及活化所制成的一种孔径均匀、导电性能好、高比表面积的纤维。制备酚醛纤维的方法主要有熔融纺丝法、湿法纺丝法以及静电纺丝法等。其中静电纺丝法由于装置简单、工序较短、直径可控,可制得纳米级纤维的特点而得到广泛研究。本文根据酚醛电纺时纺丝液体系状态的不同分别介绍了溶液静电纺丝法和熔体静电纺丝法的研究进展,并对PACF的制备过程及其特点、应用领域进行了总结,最后阐述了未来发展方向。     

熔体静电纺丝制备高通量微滤膜

为研制出低成本高效过滤微滤膜,对熔体静电纺丝制备的聚丙烯(PP)纤维过滤膜进行了探究,通过改变电压、风速及温度等参数对单、双电极熔体静电纺丝进行试验,得出熔体静电纺丝双电极电纺膜性能优于单电极电纺膜的结论。采用熔体静电纺丝双电极装置制备出平均纤维直径2μm的过滤膜,验证了采用熔体静电纺丝制备高通量过滤膜的可行性,通过对比得出熔体电纺过滤膜的纯水通量是市售孔径0.45μm PP过滤膜的5倍之多,且对大于其纤维直径的微粒的截留率高达95%以上,力学性能好,可用作预过滤膜对污水进行预处理。     

应用静电纺丝技术的电催化剂及载体材料制备研究进展

与机械拉伸等传统的纤维制备方法相比,静电纺丝技术具有操作便利、成本低、生产效率高等优点,是一种更简单、经济的纤维成型技术,被广泛应用于燃料电池、金属-空气电池、水电解装置等领域的电催化过程中。本文首先介绍了静电纺丝的工作原理、工艺影响因素及电纺技术的发展现状;之后主要介绍了静电纺丝在制备催化剂及催化载体材料上的研究进展,包括：①在碱性的电化学反应中,通过静电纺丝制备的过渡金属氧化物及金属-碳复合纤维显示出优异的电催化性能和可观的经济效益;②在水分解反应中,电纺Ir基催化剂具有均匀的一维纳米结构、极高的比表面积和良好的分散性,表现出了优异的催化活性;③在酸性的氧还原和析氧反应中,电纺氧化锡锑（ATO）载体具有优异的导电性,不仅可为催化剂提供良好的电子转移结构及催化活性位点,还能起到一定的结构保护作用,提高了催化活性和稳定性。本文总结了以静电纺丝方法制备催化剂或催化载体材料的优缺点,并发现电纺一维纳米催化剂具有出色的纤维形貌、理想的比表面积及较低的传质阻力,可有效弥补传统金属催化剂颗粒易团聚、活性低等缺点。最后,为进一步提高电纺催化剂的析氧催化性能以及实现电纺纤维排列结构的可控性,对静电纺丝技术的发展提出了几点建议和展望。     

电纺法制备纳米纤维及其应用研究

静电纺丝(电纺)技术是一种制备直径为数10 nm到数μm纳米纤维的有效方法,介绍了电纺的工作机理,对电纺条件影响纤维形态和纳米纤维应用进行了综述。最后对纳米纤维应用发展方向进行了展望。     

静电纺纳米纤维集合体力学性能增强的研究现状

介绍了静电纺纳米单纤维结构调控及静电纺纳米纤维集合体力学性能增强的研究现状,并对今后提高静电纺纳米纤维材料力学性能的研究提出建议.静电纺纳米单纤维结构调控因素包括纺丝溶液性质、纺丝参数、环境因素等.静电纺纳米纤维集合体包括纳米纤维束及纳米纤维膜,纳米纤维束力学性能的增强方法包括热拉伸法、加捻法和化学法,纳米纤维膜力学性...     

One-dimensional electrospun ceramic nanomaterials and their sensing applications

One-dimensional sensing materials that are prepared via electrospinning and controlled annealing exhibit intrinsic properties, such as electron transmissivity, magnetic susceptibility, specific heat capacity, as well as optical and mechanical characteristics. Particularly, the electronic transmission characteristics of the ceramic fiber materials, such as the electrical conductivity, photocurrent, magnetoresistance, nanocontact resistance, and dielectric properties, exhibited great potential for applications in the next generation of electronic sensing devices. First, electrospun ceramic materials with different structural and functional characteristics were reviewed here, after which the strategies for improving their properties, as well as the method for assembling the flexible devices, are summarized. Moreover, the electrospun ceramic nanofibers were detailedly discussed regarding applications in device construction and wearable electronics, such as photosensors, gas sensors, mechanical sensors, and other energy storage devices. Finally, the future development direction of the electrospinning technology for multifunctional and wearable electronics skin was proposed.     

Processing and Structure Relationships in Electrospinning of Ceramic Fiber Systems

During the last years, several groups across the world have concentrated on the adaptation and further development of electrospinning (e-spinning) to enable ceramic fiber synthesis. Thus far, more than 20 ceramic systems have been synthesized as micro- and nanofibers. These fibers can be amorphous, polycrystalline, dense, porous, or hollow. This article reviews the experimental and theoretical basis of ceramic e-spinning. Furthermore, it introduces an expanded electro hydrodynamic (EHD) theory that allows the prediction of fired fiber diameter for lanthanum cuprate fibers. It is hypothesized that this expanded EHD theory is applicable to most ceramic e-spinning systems. Furthermore, electroceramic nanofibers produced via e-spinning are presented in detail along with an overview of electrospun ceramic fibers.     

Hydraulic permeabilities of PET and nylon 6 electrospun fiber webs

The morphological and hydraulic properties of electrospun fiber webs were investigated and compared with those of spunbond nonwoven fabrics. In this study, poly(ethylene terephthalate) (PET), hydrophobic polymer, and nylon 6, with some hydrophilic groups (amide groups), were used as the polymer materials to prepare spunbonds and electrospun fiber webs. The water permeabilities of PET and nylon 6 spunbonds followed the Darcy's law, but those of PET and nylon 6 electrospun fiber webs showed properties that deviated from the Darcy's law. On the other hand, the wicking phenomenon was observed in both nylon 6 spunbond and electrospun fiber webs, but no such phenomenon was observed in PET spunbond and electrospun fiber webs. The water vapor transport rates of PET and nylon 6 electrospun fiber webs were higher than those of PET and nylon 6 spunbonds. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 167–177, 2006     

Superhydrophobic Mats of Polymer-Derived Ceramic Fibers

Solid preceramic polyaluminasilazane was synthesized through the reaction between liquid cyclosilazane and aluminum tri-sec-butoxide at 160°C. Electrospinning of polyaluminasilazane/polyethyleneoxide (1/0.0001 mass ratio) in chloroform solutions generated smooth fibers while the electrospun fibers from the chloroform/ N,N -dimethylformamide solutions had submicrometer structures on the fiber surfaces. Smooth and rough SiCNO ceramic fibers were obtained by the pyrolysis of the green fibers with an 80% yield. Superhydrophobic mats of ceramic fibers were fabricated via a chemical vapor deposition of perfluorosilane onto the rough fibers. These superhydrophobic mats possess good chemical and thermal stability.     

Filtration properties of electrospun ultrafine fiber webs

Electrospun fiber webs were prepared at various spinning conditions. The effect of electrospinning parameters on fiber morphology and filtration performance of electrospun webs was investigated. The processing variables considered were only the applied voltage and rotation speed of a drum type collector. The fiber diameter and mean pore size of the electrospun webs decreased with increasing applied voltage and collector speed. Pressure drop and aerosol collection efficiency of the electrospun fiber webs were increased with decreasing fiber and pore size. Additionally, it was found that the filtration performance of the electrospun web was much greater than that of a commercial high efficiency air filter media made of glass fibers.     

Electrospinning of thermoplastic polyurethane microfibers and nanofibers from polymer solution and melt

Electrospinning technique was used to produce ultrafine fibers from thermoplastic polyurethane (TPU). A direct comparison between melt and solution electrospinning of TPU was provided for the evaluation of process–structure relationship. It was found that the deposition rate of melt electrospinning (0.6 g h^?1) is four times higher than that of solution electrospinning (0.125 g h^?1) for TPU under the same processing condition. However, the average fiber diameters of solution electrospun TPUs (220–280 nm) were much lower than those of melt electrospun TPUs (4–8 μm). The effect of processing variables including collection distance and electric field strength on the electrospun fiber diameter and morphology was also studied. The findings indicate that increasing the electric field strength yielded more electrical forces acting on polymer jet and resulted in a decrease in fiber diameter as a result of more fiber drawing in both solution and melt electrospun fibers. It was also demonstrated that increasing the collection distance led to an improvement in the solidification of melt electrospun fibers and thus less fused fibers were obtained. Finally, a close investigation of fiber structures revealed that melt electrospun TPU fibers had smooth surface, whereas solution electrospun TPU fibers showed high intensity of cracks on the fiber surface. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Regeneration of Bombyx mori silk by electrospinning. Part 3: characterization of electrospun nonwoven mat

Regenerated Bombyx mori silk fibroin in formic acid was electrospun and the morphological, chemical and mechanical properties of these nanofibers were examined by field emission environmental scanning electron microscopy (FESEM), Raman spectroscopy (RS), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) and tensile testing. FESEM indicated that the average fiber diameter was less than 100 nm and circular in cross section. This paper maps the silk fibroin molecular conformations of each step of the sample preparation and the electrospinning process. The secondary structural compositions (random and β-sheet) of the fibroin were determined by FTIR and RS. The crystallinity index of the electrospun fiber, calculated as the intensity ratio of 1624 (β-sheet) and 1663 (random) cm⁻¹ FTIR bands was higher than that of the pristine fiber. Raman spectra of the amide I (1665 cm⁻¹, random) to amide III (1228 cm⁻¹, β-sheet) ratio of the electrospun fiber was less than that of the pristine fiber indicative of higher β-sheet content. The fiber crystallinity, determined by XRD, showed a lower value for the electrospun fiber. The electrospun fiber shows small but significant increases in the β-sheet content in comparison with the pristine fiber. Dissolution of fibroin in formic acid enhances β-sheet crystallization and may facilitate β-sheet formation in electrospun fiber. The electrospun random silk mat had a Young's modulus, ultimate tensile strength and strain of 515 MPa, 7.25 MPa and 3.2%, respectively.     

The mechanism of the controlled deposition of electrospun fibers

The controlled deposition of electrospun fibers means that the electrospun fibers can be collected in a limited and specified area and can present better applications in the fields of medical treatment, garment making, and 3D printing. In order to study the mechanism of the controlled deposition of electrospun fibers, simulation and experimental methods were used. Specifically, in the electrospinning experiment, circular copper sheets of different diameters were used as collectors. The effect of different collector areas on the morphology of fiber deposition was discussed. The electric field distribution of electrospinning with different specifications of collectors was simulated correspondingly. The experimental results show that, as compared to the traditional large flat collector, the area where the electrospun fibers are deposited is significantly reduced when a smaller circular copper plate was used as a collector. The smaller the area of the collector, the more the fibers tend to deposit at the center area of the collector, and the more likely the morphology of the product formed by the fiber deposition to exhibit a center protrusion shape. The controlled deposition of the electrospun fiber technology can provide more opportunities for the application of the electrospinning technology.     

Electrospinning of PVA-Calcium Phosphate Sol Precursors for the Production of Fibrous Hydroxyapatite

A precursor solution containing poly(vinyl alcohol) and a calcium phosphate sol is used to produce fibers of hydroxyapatite. The mixture is electrospun at a voltage of 20 kV and the resultant structure is calcined at 600°C for 6 h. Experiments were conducted for polymer molecular weight ( M _W) between 9500 and 155 000 g/mol and sol volume fractions ( V _S) between 0% and 83%. The results indicate that the electrospun fiber diameter can be correlated to the solution viscosity. The polymer molecular weight and sol volume fraction have a significant effect on the ceramic structure. Highly interconnected solid or porous hydroxyapatite fibers with diameters between 200 and 500 nm and crystal sizes between 30 and 50 nm can be produced by controlling M _W and V _S.     

Novel zein‐based electrospun fibers with the water stability and strength necessary for various applications

BACKGROUND: Some of the problems with electrospun zein fiber are that it has very low tenacities in the dry and wet states and that mats of the fiber become films when immersed in water. The fibers are therefore unusable for various applications despite their good biocompatibility and biodegradability. This research was conducted to overcome these problems by electrospinning novel fibers containing various concentrations of zein, citric acid (CA) and sodium hypophosphite monohydrate (SHP) and by crosslinking the zein with CA and with SHP serving as a catalyst. RESULTS: The CA‐crosslinked electrospun zein fiber has as much as 10‐fold greater wet tenacity and 15‐fold greater dry tenacity than regular electrospun zein fiber. The average diameter of these fibers is 451 nm, which is the smallest diameter ever reported for zein‐based electrospun fiber. A mat of this fiber retains its fibrous structure when immersed in water, and the fiber retains about 70% of its tenacity after 16 days at 50 °C and 90% relative humidity. CONCLUSION: The high dry and wet tenacities, good water stability and small diameter of the novel CA‐crosslinked electrospun zein fiber make it attractive for biomedical and other applications that expose zein to water or that require high surface area. Copyright © 2008 Society of Chemical Industry