静电纺丝工艺参数对PMMA／富勒烯纤维形貌的影响

采用甲苯与二甲基甲酰胺（DMF）混合溶液做溶剂,以静电纺丝法制备了含有富勒烯（C60）的聚甲基丙烯酸甲酯（PMMA）纤维,利用扫描电镜观察了纤维的形貌,分析了PMMA的质量分数、溶剂比、纺丝电压、收集距离等对纤维形貌及平均直径的影响。结果表明：PMMA溶液的浓度以及溶剂比对纤维的形貌起着主导作用,当二者变化时,纤维结构变化较大。纤维的平均直径随着PMMA浓废、纺丝电压的增大而增大;当甲苯/DMF体积比增大时,纤维平均直径先增大后减小;纤维形貌受收集距离的影响较小。     

气流-静电纺丝法制备苯乙烯—丁二烯—苯乙烯嵌段共聚超细纤维

采用75%四氢呋喃(THF)和25%N,N-二甲基甲酰胺(DMF)的混合溶液作溶剂,通过气流-静电纺丝法制备了苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)超细纤维。利用扫描电镜(SEM),研究了溶液浓度、电压、接收距离(喷丝孔到接收板的距离)、喷丝孔内径对静电纺纤维的直径和形貌的影响。研究发现:溶液浓度对电纺纤维的直径和形貌有非常重要的影响,当溶液浓度由10%增加到18%时,电纺纤维平均直径随之成线性增加;当电压由23.8kV增加到33.8kV时,纤维平均直径先减小后增加。最佳工艺条件为:溶液质量分数为14%,电压为28.8kV,接收距离为20cm,喷丝孔内径为0.27mm,所得SBS电纺超细纤维平均直径为429nm。     

静电纺工艺参数对SEBS纤维形貌和直径的影响

通过静电纺丝,将苯乙烯-乙烯-丁烯-苯乙烯嵌段共聚物(SEBS)溶解于四氢呋喃(THF)中的纺丝液制备成SEBS纤维,探索了纺丝液质量分数、纺丝电压和接收距离对纤维形貌及直径的影响。通过扫描电镜观察SEBS纤维的形貌以及Photoshop软件测量了SEBS纤维的直径。结果表明,纺丝液质量分数为25%、纺丝电压为10 kV、接收距离为15 cm时,纤维成型性良好,平均直径为9.7727μm;纤维直径随着电压的增大而减少,随着接收距离的增大而先减小后增大。     

气流-静电纺丝法制备P(AN-co-AA)纳米纤维的研究

用气流-静电纺丝法制备了丙烯腈-丙烯酸共聚物[P(AN-co-AA)]纳米纤维。通过扫描电镜(SEM)对纳米纤维形貌的表征,研究了聚合时丙烯酸(AA)单体的含量、溶剂种类以及工艺参数对P(AN-co-AA)纳米纤维直径和形貌的影响,得到了最佳工艺条件为:纺丝溶剂N、N-二甲基甲酰胺(DMF)、聚合单体中AA的摩尔分数比15%、P(AN-co-AA)质量分数10%、外加电压20kV、接收距离20cm,所得P(AN-co-AA)纳米纤维的平均直径为156nm。     

静电纺丝工艺对二醋酸纤维素纳米纤维形貌及直径的影响

以质量比为2∶1的丙酮/N,N-二甲基乙酰胺混合溶液为溶剂配制二醋酸纤维素(CA)溶液,采用静电纺丝制备CA纳米纤维,探讨了CA浓度、纺丝电压、接收距离和溶液推进速度等工艺条件对CA纳米纤维形貌、直径及其分布的影响。结果表明:CA纳米纤维的直径随CA浓度增加而增大,随纺丝电压增大而减小;适当的接收距离和溶液推进速度可以获得直径较小且分布均匀的纤维;当CA质量分数为11%、纺丝电压为30 k V、接收距离为15 cm、溶液推进速度为0.010 m L/min时,纺丝效果好,纤维平均直径约130 nm,且直径分布较均匀。     

静电纺丝工艺对聚乳酸纳米纤维形貌及直径的影响

以N,N-二甲基乙酰胺为溶剂配制聚乳酸(PLA)溶液,采用静电纺制备PLA纳米纤维,探讨PLA溶液浓度、纺丝电压、接收距离对PLA纳米纤维形貌、直径及其分布的影响。结果表明:当PLA溶液浓度为10%、纺丝电压为24kV、接收距离为20cm时,纺丝效果好,纤维平均直径约91nm,且直径分布较均匀。     

静电纺间位芳纶纳米纤维的制备工艺参数

通过静电纺丝方法,将氯化锂/N,N–二甲基乙酰胺(Li Cl/DMAc)溶解间位芳纶(PMIA)制备了PMIA纳米纤维,探索了溶液浓度、接收距离、纺丝电压及接收速度等工艺参数对纤维形貌及其直径分布的影响。通过扫描电子显微镜观察了PMIA纳米纤维形貌及应用Image-J软件测量统计了PMIA纤维直径。结果表明,溶液浓度为8%~10%、纺丝电压为16~18 k V、接收距离为15~20 cm,接收速度60~80 r/min的范围内,间位芳纶纳米纤维成型良好,直径分布范围为100~120 nm;PMIA纳米纤维直径随着溶液浓度的减小、静电电压的增加而减小,随着接收速度的增加纤维取向增加。     

PSA纳米纤维毡的制备和性能（英文）

以聚砜酰胺(PSA)无纺布为支撑层,采用静电纺丝法制备了PSA纳米纤维毡,并用于高温高效空气过滤领域;研究了环境湿度对PSA纤维成形的影响规律,探讨了纺丝时间、纺丝电压、接收距离对纳米纤维毡形貌、孔径、纤维直径及其力学性能的影响,以及纳米纤维毡面密度对滤材过滤效率和压阻的影响。结果表明:当环境相对湿度达到30%时,纳米纤维成形良好;当纺丝电压为22 kV,纺丝时间23 h,接收距离为16 cm时,制备的纳米纤维毡面密度为6.78 g·m~(-2),滤材过滤效率达到99.93%,过滤压阻为754 Pa,纳米纤维毡质量因子为9.63×10~(-3);PSA纳米纤维毡达到了PM2.5过滤的要求,有望在高温过滤领域得到广泛应用。     

聚ε-己内酯/聚乙二醇共混纳米纤维的静电纺丝研究

采用四氢呋喃和无水乙醇为溶剂,利用静电纺丝法制备了聚己内酯(PCL)/聚乙二醇(PEG)共混纳米纤维。研究了共混配比、溶液浓度、无水乙醇的加入以及电纺电压、接收距离等工艺参数对纤维形态和性能的影响。测试结果表明:聚乙二醇和聚己内酯以一定比例共混后改善了聚己内酯纤维毡的亲水性和细胞相容性;随着纺丝原液浓度增加,电纺产品由高分子微/纳米液滴结构渐变为珠状结构较少的平滑纤维,平均纤维直径逐渐增大;一定范围内,纤维平均直径随电压的上升而增大,但与接收距离关系不大;此外,加入无水乙醇后,共混溶液电导率增加,有利于喷射流的劈裂,减少了珠状结构的数量。     

气流-静电纺丝法制备聚对苯二甲酸乙二酯纳米纤维

采用50%苯酚和50%1,1,2,2-四氯乙烷的混合溶液为溶剂,通过气流-静电纺丝法制备了聚对苯二甲酸乙二酯(PET)纳米纤维。利用扫描电镜(SEM),研究了聚合物分子质量、溶液浓度、电压、接收距离(喷丝孔到接收板的距离)对电纺纤维形态结构的影响。结果表明:随着聚合物分子质量和溶液浓度增加,纤维平均直径也随之增加;纤维平均直径随电压的增加而减小;随接收距离的增加,纤维平均直径先减小后增加。最佳工艺条件为:聚合物特性黏度为0.818 dL/g,溶液质量分数为15%,电压为32 kV,接收距离为23 cm,所得PET电纺纳米纤维平均直径为85 nm。     

Preparation of poly(ether sulfone) nanofibers by gas‐jet/electrospinning

Poly(ether sulfone) (PES) nanofibers were prepared by the gas‐jet/electrospinning of its solutions in N,N‐dimethylformamide (DMF). The gas used in this gas‐jet/electrospinning process was nitrogen. The morphology of the PES nanofibers was investigated with scanning electron microscopy. The process parameters studied in this work included the concentration of the polymer solution, the applied voltage, the tip–collector distance (TCD), the inner diameter of the needle, and the gas flow rate. It was found from experimental results that the average diameter of the electrospun PES fibers depended strongly on these process parameters. A decrease in the polymer concentration in the spinning solutions resulted in the formation of nanofibers with a smaller diameter. The use of an 18 wt % polymer solution yielded PES nanofibers with an average diameter of about 80 nm. However, a morphology of mixed bead fibers was formed when the concentration of PES in DMF was below 20 wt % during gas‐jet/electrospinning. Uniform PES nanofibers with an average diameter of about 200 nm were prepared by this electrospinning with the following optimal process parameters: the concentration of PES in DMF was 25 wt %, the applied voltage was 28.8 kV, the gas flow was 10.0 L/min, the inner diameter of the needle was 0.24 mm, the TCD was 20 cm, and the flow rate was 6.0 mL/h. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2008     

Electrospinning of polycarbonate urethane biomaterials

Polycarbonate urethane (PCU) nano-fibers were fabricated via electrospinning using N,N- dimethylformamide (DMF) and tetrahydrofuran (THF) as the mixed solvent. The effect of volume ratios of DMF and THF in the mixed solvent on the fiber structures was investigated. The results show that nano-fibers with a narrow diameter distribution and a few defects were obtained when mixed solvent with the appropriate volume ratio of DMF and THF as 1∶1. When the proportion of DMF was more than 75% in the mixed solvent, it was easy to form many beaded fibers. The applied voltage in the electrospinning process has a significant influence on the morphology of fibers. When the electric voltage was set between 22 and 32 kV, the average diameters of the fibers were found between 420 and 570 nm. Scanning electron microscopy (SEM) images showed that fiber diameter and structural morphology of the electrospun PCU membranes are a function of the polymer solution concentration. When the concentration of PCU solution was 6.0 wt-%, a beaded-fiber microstructure was obtained. With increasing the concentration of PCU solutions above 6.0 wt-%, beaded fiber decreased and finally disappeared. However, when the PCU concentration was over 14.0 wt-%, the average diameter of fibers became large, closed to 2 μm, because of the high solution viscosity. The average diameter of nanofibers increased linearly with increasing the volume flow rate of the PCU solution (10.0 wt-%) when the applied voltage was 24 kV. The results show that the morphology of PCU fibers could be controlled by electrospinning parameters, such as solution concentration, electric voltage and flow rate.     

Electrospun nanofibers of block copolymer of trimethylene carbonate and ϵ‐caprolactone

The electrospinning behavior of a block copolymer of trimethylene carbonate (TMC) and ε‐caprolactone dissolved in N,N‐dimethylformamide (DMF) and methylene chloride (MC) was studied. The effects of the blended solvent volume ratio, concentration, voltage, and tip–collector distance (TCD) on the morphology of the electrospun fibers were investigated by scanning electron microscopy. The results indicated that the diameter of the electrospun fibers decreased with a decreasing molar ratio of MC to DMF, but beads formed gradually. With a decreasing concentration of the solution, the fiber diameter decreased; at the same time, beads also appeared and changed from spindlelike to spherical. A higher voltage and larger TCD favored the formation of smaller diameter electrospun fibers. The results of differential scanning calorimetry and X‐ray diffraction showed that the crystallinity and melting point of the electrospun fibers decreased when increasing the TMC content in the copolymer. Compared with the corresponding films, the crystallinity and melting point of the electrospun fibers were obviously increased. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1462–1470, 2006     

静电纺丝热塑性聚氨酯纳米纤维的制备

将N,N-二甲基甲酰胺（DMF）和四氢呋喃（THF）按体积比0：4、1：3、2：2、3：1、4：0混合作为溶剂,确定配比后,在不同浓度、电压下对热塑性聚氨酯（TPU）溶液进行静电纺丝。结果表明,DMF与THF的体积比对聚氨酯静电纺丝纤维的形貌、直径及其均匀性有明显影响,当混合溶液体积比为2：2,浓度为0．18g／mL,电压为26kV时,TPU纺丝液纺丝效果最佳,得到最理想的纤维;纤维直径随DMF含量的增多而减小,但当DMF含量过多时,纤维上容易出现液滴,纤维形貌变差;TPU纺丝液浓度增大,纤维直径增大;电压增大,纤维直径减小。     

不同溶剂对静电纺聚乳酸纳米纤维形态结构的影响

以聚乳酸（PLA）为原料,分别用三种不同的溶剂制得三种纺丝液并采用静电纺丝法,制备了聚乳酸纳米纤维。探讨了溶剂、电压、溶液质量分数对纤维形貌和直径的影响。结果表明,溶剂是决定PLA超细纤维形成的关键因素,三氯甲烷（CHC l3）与二甲基甲酰胺（DMF）混合溶剂（体积比为9∶1）是PLA静电纺丝较为理想的溶剂。在PLA质量分数为6%、极距15 cm、电压25 kV,流量2.5 mL/h的工艺条件下,可制备直径为1 200 nm左右的PLA纤维。     

Alignment and optimization of nylon 6 nanofibers by electrospinning

Nonwoven electrospun nylon 6 nanofibers produced with formic acid under different concentrations have been examined. The effects of the solution properties, electric field, and spinneret‐to‐collection distance on the fiber uniformity, morphology, and average diameter have been established. The optimum polymer solution concentration (20 wt %), applied voltage (15 kV), and spinning distance (8 cm) have been found to make uniform nylon 6 fibers. A simple technique that can produce a bundle of aligned electrospun fibers suspended between two grounded disks is described. Alignment and stretching of the fibers are derived by the electrostatic interactions between the positive electrode on the spinneret and the grounded disks. The gap between the disks and the collection time have been varied to systematically study the degree of alignment and the density of the collected nylon 6 fibers. The number of the distributed fibers in the bundle can be controlled by the alteration of the deposition time, the voltage, and the width of the gap. Scanning electron microscopy images have indicated a greater degree of fiber alignment with increasing disk gaps and collection times. The article also provides a comprehensive review of the design of various mechanisms for nanofiber alignment. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2008     

Enhanced mandrel design for electrospinning aligned fiber mats from low volatility solvents

A cylindrical mandrel with axially aligned rods was designed and tested for the collection of electrospun fibers. Blended polyaniline/polyethylene oxide fibers were electrospun from a solution containing a nonvolatile solvent, m-cresol. Camphorsulfonic acid served as the primary dopant and m-cresol were used as the secondary dopant to enhance fiber conductivity. A smooth, rotating cylindrical mandrel collector failed to collect and align fibers and instead afforded a wet, sticky film. An eight-rod, rotating cylindrical mandrel resulted in a dry, aligned fiber mat composed of 7–10 μm diameter fibers. Alignment was maintained for at least 18 h of continuous spinning and the resulting mat could be easily recovered from the mandrel. A simulation of the rotating system indicated that the efficient formation of dry, nonsticky, aligned fiber mat was facilitated by the high mass transfer coefficient associated with the use of corrugated rods. Experiments indicated that 6–10 rods were optimal avoiding sagging of the fibers at the low end and increased mas transfer resistance at the high end.     

Determination of optimal production parameters for polyacrylonitrile nanofibers

The object of this work is to determine the most suitable values of process and solution parameters for electrospinning of polyacrylonitrile (PAN) nanofibers including solution concentration, applied voltage, and working distance between the needle tip and the collector plate. To investigate the effects of those parameters on the fiber morphology, nanofiber mat samples were produced by changing the value of parameters systematically. The scanning electron microscope images of these samples were analyzed to realize the effects of these parameters on the nanofiber morphology. Our results demonstrate that the diameter of the fibers increases with increasing concentration. However, the diameter reduces as the applied voltage and working distance between needle tip and the collector increase up to a certain value. In addition to this, viscosity and applied voltage have a strong effect on the uniformity and morphology of the nanofibers. Moreover, a relationship between spinning distance, voltage supplied, solution concentration, charge density, bead formation, and the diameter of the electrospun PAN nanofiber were established in the study. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Effect of solvent quality and humidity on the porous formation and oil absorbency of SAN electrospun nanofibers

In this study, nanofibrous mat with high oil sorption capability was prepared via one‐step electrospinning process without any further post‐treatments. For this purpose, the fabrication of styrene/acrylonitrile copolymer nanofibers was carried out using various dimethylformamide (DMF)/tetrahydrofuran and DMF/ethanol (DMF/EtOH) binary mixture ratios in an electrospining atmosphere with various relative humidity (RH) levels. Scanning electron microscope micrographs showed that DMF/tetrahydrofuran and DMF/EtOH ratio and RH value could considerably affect the diameter, surface, and interior morphology of the resultant nanofibers. The nanofiber morphology was dependent upon the polymer/solvent(s)/water ternary phase diagram behavior. In overall, the partial hydrophilicity of styrene/acrylonitrile copolymer resulted in electrospun nanofibers with wrinkled surface. In addition, the incorporation of nonsolvent in the spinning solution and using high RH atmosphere forced the polymeric solution jet to intensively phase separate and, therefore, produce the nanofibers with highly interior porous structure during drying process. The maximal capacity and rate of oil sorption (170 g/g) was observed for the nanofibrous mat prepared using EtOH/DMF (2/3: vol/vol) and RH value of 60% showing the highest internal porosity. The results showed that the oil sorption capability and mechanical strength of the fibrous mat are strongly dependent on nanofibers diameter and porous structure, which can be controlled through adjusting the RH and spinning solvent quality. The electrospun mat with highest Young's modulus (7.68 MPa) was prepared using EtOH/DMF (2/3) binary mixture and RH value of 45%. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45586.     

The morphology of electrospun polystyrene fibers

Electrospinning is a process of electrostatic fiber formation which uses electrical forces to produce polymer nanofibers from polymer solution. The electrospinning system consists of a syringe feeder system, a collector system, and a high power supplier. The important parameters in the morphology of electrospun polystyrene fibers are concentration, applied voltage, and solvent properties. Higher concentrations of the polymer solution form thicker fibers and fewer beads. When the concentration is 7 wt%, electrospun fibers have an average diameter of 340 nm, but as the concentration of PS increases to 17 wt%, the fiber diameter gradually thickens to 3,610 nm. The fiber morphology under different solvent mixture ratios and solvent mixtures has also been studied.