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。     

静电纺PCL纤维形态与热性能的研究

利用静电纺丝法制备了超细聚ε-己内酯(PCL)纤维;借助扫描电镜仪和差示扫描量热仪表征了PCL纤维的形态与热性能;研究了电纺过程中溶液浓度、电压、接收距离和纺丝速度对纤维形态的影响。结果表明:当纺丝电压为10 kV,接收距离为15 cm,纺丝速度为2 mL/min时,纺丝液中PCL质量分数为6%~12%能获得连续无串珠的纤维;纺丝电压为8~12 kV,电纺过程稳定;接收距离对纤维的直径和形貌无明显影响;与流延成型的PCL膜相比,电纺PCL纤维具有较低的结晶度。     

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。     

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。     

聚醚砜的静电纺丝研究

采用聚醚砜(PES)的良溶剂二甲基甲酰胺(DMF)和非良溶剂丙酮(AC)为共溶剂体系,研究了溶剂组成、纺丝成形条件对静电纺丝PES纤维的形貌及纤维直径的影响。结果表明:DMF/AC的配比对于静电纺丝PES纤维形貌具有直接的调控作用,随着DMF/AC混合溶剂中AC用量的增加,纤维平均直径变大,纤维毡中串珠数目明显减少,纤维均一性变好;随着纺丝液浓度的升高,纺丝电压的增大,纤维的平均直径变大;接收距离的变化对纤维平均直径影响不大;PES最佳纺丝工艺条件为纺丝溶液质量分数13%,纺丝电压15 kV,接收距离10 cm,mDMF/mAC为8.5/1.5,在此条件下,可以获得纤维平均直径为96 nm的PES纤维毡。     

熔体静电纺丝的电场分布及其对PET纤维成形的影响

借助ANSYS软件模拟聚对苯二甲酸乙二酯(PET)熔体静电纺丝在不同参数(纺丝电压、接收距离、接收板面积)条件下的电场分布,探讨电场分布对熔体静电纺丝PET射流运动与纤维形貌的影响。结果表明,在单喷嘴–平板结构模型中,提高纺丝电压将增强整体空间电场强度,使电场对PET熔体射流的控制力加强,PET熔体射流的摆动半径减小,当纺丝电压由24 k V升高到30 k V时,摆动半径由11.7 mm减至9.9 mm,而摆动角增大,由10.1°增至11.2°,PET纤维直径显著减小,由3.275μm减至2.202μm;接收距离的改变对接收板表面电场的影响显著,随着接收距离的增加,PET射流的直线段比例明显下降,当接收距离由50 mm增加至90 mm时,PET熔体射流的直线段比例由68.0%减至54.0%,PET纤维直径在适中接收距离(70 mm)下表现较细,可达2.184μm;接收板面积的减小加强了对PET熔体射流的控制,使PET熔体射流直线段比例显著增加,当接收板面积由15 cm×15 cm减小至10 cm×10 cm时,PET熔体射流直线段比例由68.0%增加至82.6%,摆动半径减小,由9.9 mm减至4.2 mm,沉积角因PET熔体射流贴服接收板而减小,由12.2°减至9.1°,PET纤维直径稍有增加,由2.202μm增加至2.537μm。     

静电纺丝法纺制聚乳酸纳米纤维无纺毡

采用静电纺丝法制备了生物降解聚乳酸(PLLA)纳米纤维无纺毡。分析了纺丝液浓度、电压、接收距离、挤出速度等因素对纤维形态的影响。结果表明:纺丝液的浓度和挤出速度对纤维直径的影响较为明显,溶液挤出速度增大,所得纤维微孔含量及尺寸也增大;适当的电压和接收距离有利于收集无液滴纤维;随着纤维直径的减小,无纺毡的孔径呈减小趋势。在PLLA质量分数为5．7％、挤出速度0．8 mL／h、接受距离 15．5 cm、电压8 kV的静电纺丝条件下,可制备纤维直径为200-400 nm的PLLA纳米纤维无纺毡。     

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。     

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。     

Melt electrospinning from poly(L‐lactide) rods coated with poly(ethylene‐co‐vinyl alcohol)

Rodlike poly(L ‐lactide) (PLLA) samples coated with poly(ethylene‐co‐vinyl alcohol) (EVOH) were made. Fibers were produced from these rodlike samples by using a melt electrospinning system equipped with a laser irradiating device, and the effects of EVOH content and the processing parameters of the melt electrospinning on fiber diameters were investigated. We also studied the fiber formation mechanism from the rods during the laser melt electrospinning process. The following conclusions were reached: (i) coating of EVOH on PLLA rods has a remarkable effect on decreasing fiber diameter from 3 μm to around 1 μm; (ii) increases in the electric field strength and temperature of spinning space decrease the average diameter of fibers produced from pure PLLA rods, and longer collector distance leads to lager PLLA fiber diameter; and (iii) the migration of PLLA component from the core to the surface of electrospun fibers takes place during the fiber formation process. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Electrospun composite fibers of polyvinylpyrrolidone with embedded poly(methyl methacrylate)–polyethyleneimine core–shell particles

Composite fibers consisting of poly(methyl methacrylate)–polyethyleneimine (PMMA–PEI) core–shell particles embedded in polyvinylpyrrolidone (PVP) were successfully fabricated by the electrospinning method. The electrospun fibers were produced using 18?% w/v aqueous PVP solution blended with 2?% w/v PMMA–PEI particles at various pH (1, 2, 3, and 4) with a fiber collection distance set at 10?cm. The applied electrical voltages (10, 12, 14, and 16?kV) significantly affected the morphology and diameter of the prepared composite fibers (141–353?nm). The smallest composite fibers were obtained from the spinning mixture at pH 2 and a voltage of 14?kV. The composite fibers would potentially be applied as drug and bioactive compound carriers.     

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     

Transparent lead lanthanum zirconate titanate (PLZT) ceramic fibers for high-frequency ultrasonic transducer applications

This paper presents fabrication of transparent lanthanum zirconate titanate (PLZT) fibers using extrusion technique. The diameter of the sintered PLZT fiber is about 400-μm, and the fibers exhibit very good transparency. Measured dielectric constant, remnant polarization and coercive field of PLZT fiber were found to be 2340, 22.5-μC/cm², and 9.8-kV/cm, respectively. The transparent piezoelectric materials may exhibit great potential for Photoacoustic (PA) imaging and hybrid intravascular imaging combining OCT and ultrasound imaging by using the transparent fiber as the path of light propagation and ultrasonic transducer material. In our study, these transparent PLZT fibers were designed to fabricate two types of high-frequency ultrasonic transducers: small aperture single PLZT fiber/epoxy composite and large aperture 1–3 PLZT fiber/epoxy composite ultrasonic transducers. Besides, a 20-μm tungsten wire phantom and the cornea of the porcine eye were also imaged with the 1–3 PLZT fiber/epoxy composite ultrasonic transducer to demonstrate its imaging capability.     

Preparation and experimental parameters analysis of laser melt electrospun poly(L‐lactide) fibers via orthogonal design

Laser melt electrospinning is a novel technology to produce micro/nanofibers. This solvent‐free process is more suitable for biomedical applications. In this work, the electrospun poly(L ‐lactide) (PLLA) fibers with diameters ranging from 2 to 7 μm were prepared by this method, and four influencing factors of melt flow rate (MFR), laser current, collector distance, and applied voltage were investigated on the PLLA fiber diameters and its standard deviation (SD) with an orthogonal design method. The results of range analysis showed the order of significance levels as follows: applied voltage, laser current, collector distance, and MFR for fiber diameter. The SD of fiber diameter can be listed in the following order: applied voltage, MFR, laser current, and collector distance. POLYM. ENG. SCI., 52:1964–1967, 2012. © 2012 Society of Plastics Engineers     

静电纺丝制备聚己内酯载药纤维工艺参数研究

选用聚己内酯作为载体材料、5–氟尿嘧啶作为承载药物,研究了静电纺丝过程中纺丝液浓度、纺丝电压及收集距离对纤维直径的影响,对制备的聚己内酯载药纤维膜进行元素检测分析及力学性能测试,通过体外药物释放实验,验证了聚己内酯载药纤维膜药物控释的效果。结果表明,随着纺丝液的浓度和收集距离增加,纤维的平均直径增大;随着纺丝电压增加,纤维的平均直径减小。通过元素检测,验证了聚己内酯纤维膜内5–氟尿嘧啶的存在。在纺丝液浓度0.4 g/mL、纺丝电压10 kV、收集距离20 cm、载药量0.8 g的情况下,聚己内酯载药纤维膜纤维平均直径最小,达到13.92μm,对应的拉伸强度为2.88 MPa。使用磷酸缓冲盐溶液模拟体液,在温度(37±0.5)℃下进行了体外释药实验,结果表明,该纤维膜在1000 h内,可以实现药物的控制释放。为确定静电纺丝法制备聚己内酯载药纤维膜工艺参数提供了有益借鉴,并为下一步优化工艺参数奠定了基础。