共查询到19条相似文献,搜索用时 109 毫秒
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采用同轴静电纺丝技术,以聚丙烯腈(PAN)溶液为核层、聚苯乙烯(PS)溶液为壳层,制备了PAN@PS复合纳米纤维。研究了纺丝液浓度、溶剂种类对PAN@PS复合纳米纤维形貌和结构的影响。结果表明:PS/四氢呋喃(THF)作为壳层溶液的复合纳米纤维(PAN@PS/THF)可获得相界面清晰的同轴纤维。随PS纺丝液浓度的增加,纤维的直径先增大后有所减小,整体呈现递增的趋势,当PS/THF质量分数为20%时,纤维直径约为693 nm且表面光滑。而以质量分数为20%的PS/二甲基甲酰胺(DMF)为壳层溶液的复合纳米纤维(PAN@PS/DMF)直径有所增加且纤维表面凹凸不平,呈现双相连续的结构。因此,在静电纺丝过程中,可以通过改变纺丝液的参数来调节纤维的形貌和结构。 相似文献
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《合成纤维工业》2015,(5):1-4
采用磁场辅助静电纺丝法制备了有序聚丙烯腈(PAN)纳米纤维,分析了PAN/二甲基甲酰胺(DMF)溶液浓度、纺丝电压、注射速度、磁铁间距和溶剂DMF及DMF与二甲基亚砜(DMSO)混合溶剂等因素对PAN纤维有序度的影响。结果表明:随着PAN/DMF溶液中PAN浓度增大,PAN纤维有序度逐渐增大;注射速度对纤维有序度影响不明显;随着纺丝电压和磁铁间距增大,PAN纤维有序度先增大后减小;DMSO的加入,使溶液可纺性降低,不利于纤维有序排列;对于PAN/DMF溶液体系,适宜的磁场辅助静电纺丝的工艺参数为PAN质量分数12%,纺丝距离12 cm,电压14 k V,注射速度0.5 m L/h,磁铁间距2.5 cm,纺丝得到的PAN纳米纤维的有序度为92%。 相似文献
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《现代塑料加工应用》2019,(6)
研究了纺丝液浓度对聚丙烯腈(PAN)静电纺丝纤维直径,以及对PAN静电纺丝纳米纤维膜复合滤材过滤性能的影响。测试结果表明,纺丝液浓度增加,静电纺丝纤维直径变粗,孔径增大,其中质量分数为16%的纺丝液具有良好的纺丝性能,静电纺丝所得的纳米纤维直径均匀,复合后滤材在颗粒直径0.3μm,过滤风速5.3 cm/s的测试条件下,过滤效率达到99.98%,阻力为138 Pa,达到H13级别,具有高效低阻特性。 相似文献
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姜立军 《高科技纤维与应用》2011,36(3):13-17
通过实验对二甲基亚砜(DMSO)法聚丙烯腈(PAN)原丝的纤维凝固成形、水洗、牵伸、干燥定型条等湿法纺丝工艺对纤维性能的影响进行了研究,实验结果表明:增大喷丝板孔径,有利于提高原丝的取向度和干燥收缩率;调节凝固浴质量分数和温度,可生产出综合性能较好的原丝;提高水洗温度有利于制得性能好的原丝;热水、沸水和蒸汽3级牵伸工艺... 相似文献
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采用原位聚合法制备了氧化石墨烯/聚丙烯腈(GO/PAN)共聚物,研究了GO对丙烯腈聚合及PAN纺丝溶液流变性能的影响。结果表明,GO对聚合反应有一定的抑制作用,GO/PAN的相对分子质量和转化率均随着GO质量分数的增加而减小;GO的加入增加了PAN的流动性,GO/PAN溶液的储能模量、损耗模量和粘度均随着GO质量分数的增加而减小,并且随着GO质量分数的增加更倾向于粘性。 相似文献
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采用浓硝酸和浓硫酸混合溶液将多壁碳纳米管(MWNTs)进行功能化处理,与聚丙烯腈(PAN)共混,通过静电纺丝制备了PAN/MWNTs纳米纤维薄膜。分析了MWNTs的结构和分散性及PAN/MWNTs纳米纤维的性能。结果表明,经过混酸处理后,MWNTs表面产生了羧基官能团,可以长时间稳定均匀分散在N,N′-二甲基乙酰胺(DMF)溶液中。混酸处理后的MWNTs在PAN基体中均匀分散,减少了静电纺丝过程中珠滴地形成。添加MWNTs后,PAN纳米纤维的强度提高,含MWNTs质量分数5%的PAN纳米纤维的拉伸强度提高了35.48%。 相似文献
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超高相对分子质量聚丙烯腈浓溶液的制备 总被引:1,自引:0,他引:1
通过高速搅拌剪切,使超高分子对质量聚丙烯腈(PAN)冻胶体系中缠结网络结构破坏,粘度降低,提高溶液浓度,以满足纺制高性能冻胶纺PAN纤维的需要,当高速搅拌条件为间隙0.28mm剪切速率420r/min时,可解除天生缠结,适宜的搅拌剪切条件是制行适合冻胶纺的超高相分子质量PAN溶液的关键。 相似文献
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Juthawan Sutasinpromprae Sujinda Jitjaicham Manit Nithitanakul Chidchanok Meechaisue Pitt Supaphol 《Polymer International》2006,55(8):825-833
The present contribution reports the fabrication and characterization of ultrafine polyacrylonitrile (PAN) fibers by electrospinning and further development of the as‐spun PAN fibers into ultrafine carbon fibers. The effects of solution conditions (i.e., solution concentration, viscosity, conductivity, and surface tension) and process parameters (i.e., applied electrostatic field strength, emitting electrode polarity, nozzle diameter, and take‐up speed of a rotating‐drum collector) on morphological appearance and average diameter of the as‐spun PAN fibers were investigated by optical scanning (OS) and scanning electron microscopy (SEM). The concentration, and hence the viscosity, of the spinning solutions significantly affected the morphology and diameters of the as‐spun PAN fibers. The applied electrostatic field strength and nozzle diameter slightly affected the diameters of the as‐spun fibers, while the emitting electrode polarity did not show any influence over the morphology and size of the as‐spun fibers. Utilization of the rotating‐drum collector enhanced the alignment of the as‐spun fibers. Within the investigated concentration range, the average diameter of the fibers ranged between 80 and 725 nm. Finally, heat treatment of the as‐spun fibers with their average diameter of about 450 nm was carried out at 230 and 1000 °C, respectively. Various characterization techniques revealed successful conversion into carbon fibers with an average diameter of about 250 nm. Copyright © 2006 Society of Chemical Industry 相似文献
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Rheology of polyacrylonitrile‐based precursor polymers produced from controlled (RAFT) and conventional polymerization: Its role in solution spinning 下载免费PDF全文
Polymer solutions in dimethyl sulfoxide (DMSO) as a solvent, made from reversible addition fragmentation chain transfer (RAFT)‐mediated polyacrylonitrile (RAFT¥ PAN) terpolymer with molecular weight (MW) of 260,000 g/mol and dispersity (Ð) of 1.29, behave differently under applied shear stress than polymer solutions made from conventional PAN (Control PAN) with similar MW (258,000 g/mol) but Ð of 2.05 in the same solvent. The unique rheology of RAFT PAN is because of the reduced amount of high MW polymer fractions. Specifically, a 25% (w/v) polymer solution of RAFT PAN had a viscosity of 198 Pas while the equivalent control PAN polymer solution had a viscosity of 968 Pas at a shear rate of 1 s?1. Also, RAFT PAN polymer solutions had a longer Newtonian plateau than control PAN polymer solutions. This exhibits more liquid character in RAFT PAN polymer solutions than control PAN polymer solutions at same temperature and concentration. In dynamic tests, RAFT PAN polymer solutions gelled slower than their equivalent control PAN polymer solutions because of their longer polymer chain relaxation times. Slow gelling and higher liquid character in RAFT PAN polymer solutions can result in obtaining stronger and finer precursor fibers during wet spinning. Since RAFT PAN polymer solutions exhibit low viscosity and higher liquid character when compared to its equivalent control PAN at same concentration and temperature, these can allow a wider working window for wet spinning and can also allow higher solid content in the polymer solutions that remain easy to wet spin. This is expected to lead to compact and finer fibers with less voids and higher strength. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44273. 相似文献
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以碳纳米管(MCNT)和碳黑(CB)为添加剂,采用溶液共混的方法,讨论了添加剂浓度、放置时间、温度、剪切速率对聚丙烯腈溶液的表观黏度及黏流活化能(ΔΕη)的影响。结果表明:随着MCNT含量的增加,聚丙烯腈溶液的黏度先增大后减小,添加1.0%MCNT时,聚丙烯腈溶液的黏度最大,活化能也同时达到最大;随着碳黑含量的增加,黏度与活化能都随之增加,但增加幅度不大。两种PAN溶液都属于明显的切力变稀的非牛顿流体,随着剪切速率的增加,黏度下降;但在高切变速率(>800s-1)时,黏度几乎不变。 相似文献
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Xiao-Hua Ma Yu Bai Yue Cao Zhen-Liang Xu 《Korean Journal of Chemical Engineering》2014,31(8):1438-1443
Porous stainless steel hollow fiber has been widely used due to its high mechanical strength, excellent thermal conductivity and good sealing properties compared with other porous supports. We successfully prepared porous stainless steel hollow fibers using polyacrylonitrile (PAN) as polymer via dry-wet spinning followed by sintering through temperature programming method. The PAN concentration had an obvious impact on the structure and property of porous stainless steel hollow fiber even if it would be burned off during sintering. The results showed that the morphology could be tuned by adjusting the concentration of PAN. With increasing PAN concentration in casting solution for spinning, the viscosity was increased dramatically, resulting in much compact structures with high pure water flux (higher than 3×105 L·m?2·h?1·Pa?1). A more dense structure could be obtained by adding additive polyvinylpyrrolidone (PVP) as viscosity enhancer. 相似文献
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Uniform and bead-free pure polyacrylonitrile (PAN) and its magnetic polymer nanocomposite (PNC) fibers reinforced with different core-shell Fe@FeO nanoparticles (NPs) loadings are prepared using electrospinning method. The morphology of the resulting products is correlated to the corresponding rheological behaviors of the pure PAN and PAN/Fe@FeO solutions. The diameter of the PAN fibers is linearly related to the polymer solution concentration. However, with a fixed PAN concentration of 10 wt%, the Fe@FeO NP loading shows a negligible effect on the morphology of the PNC fibers. Thermogravimetric analysis (TGA) results indicate an enhanced thermal stability of the PNC fibers than that of the pure PAN fibers. Magnetic carbon nanocomposite (MCNC) fibers are prepared through the stabilization and carbonization of the electrospun PNC fibers. The effects of the heating procedures, including the stabilization and carbonization temperature and time, on the fiber morphology are systematically investigated. Both short and long MCNC fibers could be easily produced by changing the heat procedures. Room temperature magnetic properties of the nanocomposite fibers based on different heating procedures are also studied in this work. 相似文献
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Polyacrylonitrile (PAN) hollow fibers were pretreated with ammonium dibasic phosphate aqueous solution, then further oxidized in air, carbonized in nitrogen, and activated with carbon dioxide. The effects of pretreatment concentration of ammonium dibasic phosphate aqueous solution on the microstructure, specific surface, pore size distribution, and adsorption properties of PAN‐based activated carbon hollow fibers (PAN‐ACHF) were studied in this work. After the activation process, the Brunaner‐Emmett‐Teller (BET) surface area of the PAN‐ACHF and surface area of mesopores in the PAN‐ACHF increases and reaches 513 m2g?1 and 66 m2g?1 respectively when the concentration of ammonium dibasic phosphate aqueous solution is 4% (wt %). The adsorptions to creatinine are much high, reach more than 90% over all the concentration of ammonium dibasic phosphate aqueous solution. The adsorptions to VB12 of PAN‐ACHF reach 86% when the concentration of ammonium dibasic phosphate aqueous solution is 4% (wt %). The dominant pore sizes of mesopores in PAN‐ACHF range from 2 to 5 nm. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 相似文献
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