静电纺特殊结构纳米纤维的研究现状

纳米级纤维具有优良的机械性能和高比表面积等特性.以静电纺特殊结构纳米纤维为研究对象,根据其表观形态分别介绍了一维特殊结构纳米纤维、二维特殊结构纳米纤维膜、三维结构纳米纤维气凝胶等,并阐述了各种结构的形成机理.总结了近年来国内外采用静电纺丝技术制备特殊结构纳米纤维的调控方法,如改变溶液性质(溶液浓度、黏度、表面张力、电导...     

静电纺无机纳米纤维的研究进展

综述了静电纺丝制备无机纳米纤维的最新研究进展,主要介绍了电纺氧化物纳米纤维和多组分纳米纤维的研究进展,说明了各种无机纳米纤维的特性、应用前景,并且指出其不足以及今后研究的主要方向.     

静电纺纳米纤维市场前景看好

20世纪90年代后期，科学家们对于纳米纤维制备及应用的研究达到高潮，开发了一系列制备聚合物纳米纤维的方法，如纺丝、模板合成法、相分离法、自组装法以及静电纺丝法等。与上述方法相比，静电纺制备聚合物纳米纤维具有设备简单、操作容易以及高效等特点，是制备聚合物连续纳米纤维最有效的方法。静电纺纳米纤维性能优异、应用广泛，在电子器件、生物医学领域、滤材、防护服用材料纤维增强复合材料及传感器感知膜的应用前景十分看好，产业化市场发展前景广阔。     

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。     

静电纺纳米纤维的应用

综述了静电纺纳米纤维在保护性服用材料、传感器、过滤防护材料、高分子纳米模板、纳米复合改性材料、航空航天等方面的应用;详述了在生物医用材料方面的应用;展望了静电纺丝纳米纤维的发展前景;指出应继续研发具有特殊性能的静电纺纳米纤维新产品,扩大其应用领域,最终实现成果产业化。     

电纺纳米纤维增强聚合物复合材料的研究进展

与作为填料的普通纤维相比,通过静电纺丝所得纳米纤维(简称电纺纳米纤维)的长径比及比表面积较大,相对于基体材料具有较大的模量和韧性,对聚合物基体有较好的力学增强效果;电纺纳米纤维在复合材料中应力集中程度低、与聚合物基体间界面结合较好。加入电纺纳米纤维可以提高复合材料的性能,如拉伸及弯曲强度、模量,抗冲击性能等都有较大提高。电纺纳米纤维在聚合物基体中的分散及其与基体间的界面黏结等问题有待进一步研究和改善。     

静电纺纳米纤维的研究及应用进展

简述了静电纺丝基本原理及纺丝过程中射流存在的几种不稳定性形式;探讨了静电纺丝制备纳米纤维的主要影响因素。回顾了静电纺丝的发展历程,介绍了纳米纤维在电子器件、生物医学领域、滤材、防护服用材料纤维增强复合材料及传感器感知膜等方面的应用。指出静电纺纳米纤维性能优异、应用广泛,应用于生物医学领域是研发热点,必将进一步产业化。     

静电纺聚酰亚胺纳米纤维的制备及其应用

综述了静电纺聚酰亚胺纳米纤维不同制备方法及各自优缺点,对静电纺聚酰亚胺纳米纤维的改性,提高其力学性能、热稳定性及其它特性,以及聚酰亚胺纳米纤维的潜在应用领域。综述表明,寻找适合的溶剂是实现一步法静电纺高性能聚酰亚胺纳米纤维的关键,通过改性调控可提高其热稳定性和力学性能。     

PA6静电纺纳米纤维

讨论了PA6静电纺丝工艺,利用扫描电镜(SEM)观察纤维的形态结构,研究了影响PA6静电纺丝 的因素及其对所形成纤维的形态、直径的影响。结果表明,在甲酸溶液中,PA6质量分数为8％、电压值为15 kV、喷丝头到收集板的垂直距离为20 cm是PA6静电纺丝的最佳工艺条件,可得到直径小于100 nm的PA6 纳米纤维。     

静电纺丝制备纳米级纤维的研究

首先介绍了静电纺丝制备纳米纤维的原理及其影响因素,然后归纳、总结了当前国内外静电纺丝制备纳米纤维的研究内容,并对今后的研究提出了建设.     

Structure and mechanical properties of nanofibrous ZrO2 derived from alternating field electrospun precursors

Nanofibrous zirconia (ZrO₂) meshes were prepared from precursor fibers which were synthesized using the method of free-surface, high-yield alternating field electrospinning (AFES). The weight ratio of zirconyl chloride salt to polyvinylpyrrolidone (PVP) polymer in liquid precursors was investigated for its effect on the spinnability and formation of precursor fibers as well as on the resulting fibrous ZrO₂. The precursor fiber generation measured at a rate up to 5.6 g/h was achieved with a single flat 25-mm diameter alternating current (AC) electrode, which corresponded to production of up to 1.5 g/h of fibrous ZrO₂. The calcination process involved annealing the fibers at temperatures which ranged from 600 °C to 1000 °C and produced 0.1–0.2 mm thick fibrous ZrO₂ meshes. Individual nanofibers were found to have diameters between 50 and 350 nm and either a tetragonal (t-ZrO₂) or monoclinic (t-ZrO₂) structure depending on the calcination temperature. The annealed meshes with total porosity between 98.0 ± 0.2% and 94.6 ± 0.2% showed little deformation or cracking. Tensile strength and modulus of fibrous t-ZrO₂ meshes strongly depended on porosity and varied from 0.07 ± 0.03 MPa to 1.05 ± 0.3 MPa and from 90 ± 40 MPa to 388 ± 20 MPa, respectively. The m-ZrO₂ meshes resulted similar moduli, but much lower strengths due to their brittleness. A power-law relationship between the elastic modulus and porosity of AFES-derived nanofibrous t-ZrO₂ meshes, in comparison with other porous zirconia materials, was also investigated. The results of this study have demonstrated the feasibility of free-surface AFES in sizeable production of zirconia nanofibers and highly porous nanofibrous ceramic structures.     

Improvement of physical and mechanical properties of electrospun poly(lactic acid) nanofibrous structures

Iranian Polymer Journal - The electrospinning of stereocomplexed poly(lactic acid) (Sc-PLA) twisted yarns was our approach to produce PLA-based nanofibrous structures with improved physical and...     

静电纺抗紫外PVA/芦丁纳米纤维膜的制备及其性能研究

以聚乙烯醇(PVA)为原料,以芦丁为改性剂,将PVA与芦丁共混于去离子水中,通过静电纺丝制备抗紫外PVA/芦丁纳米纤维膜,并对其性能进行表征。结果表明:静电纺丝工艺条件为电压20 k V,纺丝速度0.5 m L/h,接收距离10 cm,温度30℃;加入少量芦丁,对PVA静电纺丝成纤性无影响,但纤维直径增大,直径均匀性变差;纤维中PVA与芦丁之间存在氢键;相对PVA,芦丁质量分数为4.76%时,PVA/芦丁纳米纤维膜的纤维平均直径为302 nm,抗紫外系数大于40,具有良好的抗紫外性能。     

Water absorption and mechanical properties of electrospun structured hydrogels

Electrospun nanofibers are made when electrostatic forces overcome the surface tension of a polymer solution, causing an electrically charged jet to be ejected; as the jet travels through the air, the solvent evaporates, leaving behind an electrically charged fiber, which can be collected in the form of a nonwoven sheet. A superabsorbent was added to a polymer solution containing an elastomer (concentrations = 0–85%). The mixture was electrospun, producing nanofibers in which the superabsorbent particles were held in place with nanoscale elastic fibers. The nanofibers were tested for absorbency in water and synthetic urine. Fluid absorption by the nanofibers led to the formation of structured hydrogels. Increases in the weight gain from water absorption ranged from 400 to 5000%. The linear dimensions of samples cut from the nonwoven sheet were measured; wetting the superabsorbent increased the thickness dimension of the sheet dramatically and produced a smaller change in the plane of the sheet. The rate of water absorption was calculated; the samples containing 0–70% superabsorbent reached essentially their maximum absorbency within 5 s. The excellent strength and elasticity of the wet samples make these structured hydrogels ideal for many uses, including wound care, drug delivery, and sanitary goods. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 95: 427–434, 2005     

Development of functional nanofibrous membrane assemblies towards biological sensing

A novel research approach was investigated that has the potential to improve sample preparation for complex matrices. Generation of high surface area nanofibrous membranes with covalently attached molecular recognition elements for selective capture of target biological agents were developed using the electrospinning fabrication technique. Two types of electrospun capture membranes were fabricated containing either carboxyl (COOH) or amine (NH₂) functional groups for covalent attachment of antibodies. The carboxyl functional membrane was produced by electrospinning polyvinyl chloride (PVC) formulated to be 1.8% carboxylated. The amine functional membrane was made by co-electrospinning two polymers, water-soluble polyamine and water insoluble polyurethane. Linking of molecular recognition groups, antibodies, to the carboxylated PVC was performed using established crosslinking chemistries. Antigen/antibody experiments were tested on the electrospun membranes. Results showed that electrospun membranes, treated with a secondary antibody used as the analyte, reacted only with its complement as indicated with a chemiluminescent signal. Toxin studies with Staphylococcal enterotoxin B (SEB) were conducted using avidin/biotin chemistries on the electrospun membranes. Experiments were performed using a modified ELISA sandwich assay on the fibrous membranes in the following configuration: avidin–biotinylated SEB antibody–SEB toxin–SEB antibody–HRP. Results have shown that 1–100 ng/ml concentrations of toxin were detected using a chemiluminescent signal detection scheme.     

High-flux microfiltration filters based on electrospun polyvinylalcohol nanofibrous membranes

A novel class of high-flux microfiltration filters consisting of an electrospun nanofibrous membrane and a conventional non-woven microfibrous support is being presented. The nanofibrous non-woven layer was fabricated by electrospinning of polyvinylalcohol (PVA) directly onto the microfibrous support and then followed by chemical cross-linking with glutaraldehyde (GA) in acetone. By altering the processing parameters, such as the applied voltage and the distance between the spinneret and the collector, as well as the concentration of PVA solution, electrospun PVA membranes with an average fiber diameter of 100 ± 19 nm were obtained. Characterizations revealed that the mean pore size of the electrospun PVA membranes ranged from 0.30 μm to 0.21 μm with the electrospun PVA membrane thickness varying from 10 m to 100 μm. Due to the high porosity, microfiltration filters based on these electrospun membranes showed 3–7 times higher pure water flux than the Millipore GSWP 0.22 μm membrane. The nanofibrous PVA membranes with an average thickness of 20 μm could successfully reject more than 98% of the polycarboxylate microsphere particles with a diameter of 0.209 ± 0.011 μm, and still maintain 1.5–6 times higher permeate flux than that of the Millipore GSWP 0.22 μm membrane.     

Investigation on jet stability,fiber diameter,and tensile properties of electrospun polyacrylonitrile nanofibrous yarns

Electrospinning is a flexible and efficient method for producing nanofibers by using relatively dilute polymer solution. However, there are many parameters related to material and processing that influence the morphology and property of the nanofibers. This study investigates the influence of electric field and flow rate on diameter and tensile properties of nanofibers produced using polyacrylonitrile (PAN)‐dimethylformamide (DMF) solution. Stability of the spinning jet is investigated via fiber current measurement and an image system at different electric fields and solution flow rates. It is observed that a set of electric field and flow rate conditions favor producing thinnest, strongest, and toughest nanofibers during electrospinning process. Other conditions may lead to instability of the Taylor cone, discontinuous jet, larger diameter fiber, and lower mechanical properties. Finally, a simple dynamic whipping model is adopted to correlate the nanofiber diameter with volumetric charge density and is found to be excellent validating our experimental results. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41918.     

Surface modification of electrospun chitosan nanofibrous mats for antibacterial activity

Chitosan (CS) blended with poly(ethylene oxide) (PEO) was electrospun into nanofibrous mats. The spinning solution of 6.7 : 0.3 (% w/v) of CS : PEO was dissolved in a 70 : 30 (v/v) trifluoroacetic acid/dichloromethane solution. The obtained fibers were smooth without beads on their surfaces and average diameter of the fiber was 272 ± 56 nm. N‐(2‐hydroxyl) propyl‐3‐trimethyl ammonium chitosan chloride (HTACC) and N‐benzyl‐N,N‐dimethyl chitosan iodide (QBzCS) were each prepared from the CS/PEO mats. They were identified by Fourier‐transform infrared and X‐ray photoelectron spectroscopy and degree of swelling in water. Both quaternized electrospun chitosan mats exhibited superior antibacterial activity to the unmodified electrospun CS/PEO against Staphylococcus aureus and Escherichia coli at short contact times. After 4 h of contact, the reduction of both bacterial strains by CS/PEO, HTACC, and QBzCS was equal at about 99–100%. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40981.     

Gelatin electrospun nanofibrous matrices for cardiac tissue engineering applications

The generation of in vitro tissue constructs using biomaterials and cardiac cells is a promising strategy for screening novel therapeutics and their effects on cardiac regeneration. Current cardiac mimetic tissue constructs are unable to stably maintain functional characteristics of cardiomyocytes for long-term cultures. The objective of our study was to fabricate and characterize nanofibrous matrices of gelatin for prolonged cultures of primary cardiomyocytes which previously has been used as copolymer or hydrogels. Gelatin nanofibrous matrices were successfully electrospun using a benign binary solvent, cross-linked without swelling and fusing and evaluated by scanning electron microscopy (SEM) and uniaxial tensile measurement. Scaffolds exhibited modulus 19.6 ± 3.6 kPa similar to native human myocardium tissue with fiber diameters of 200–600 nm and average porosity percentage of 49.9 ± 5.6. Myoblasts showed good cell adhesion and proliferation. Neonatal rat cardiomyocytes cultured on gelatin nanofibrous matrices showing synchronized contracting cardiomyocytes (beating) for 27 days were studied by video microscopy. Confocal microscopic analysis of immunofluorescence stained sections indicated the presence of cardiac specific Troponin T in long-term cultures. Semiquantitative RT-PCR analysis of 3D versus 2D cultures revealed enhanced expression of contractile protein desmin. Our studies show that the biophysical and mechanical properties of electrospun gelatin nanofibers are ideal for in vitro engineered cardiac constructs (ECC), to explore cardiac function in drug testing and tissue replacement. Together with stem cell techniques, they may be an ideal platform for prolongedin vitro studies in alternatives to animal usage for the pharmaceutical industry.