电纺PAN纳米纤维的碳化工艺研究

研究了电纺方法制备的聚丙烯腈(PAN)纳米纤维的碳化工艺。利用热重/差热(TG/DTA)分析仪对其升温过程中的物理化学反应过程进行了分析,讨论了在空气和氮气两种氛围内原纤维的热氧化、分解过程,发现在290℃附近PAN纤维发生强烈的氧化反应,温度达到930℃时,原纤维几乎完全转化为碳纤维。利用扫描电镜(SEM)和Raman光谱仪对不同温度下稳定化和碳化处理得到PAN基碳纤维进行了深入的研究,得到了电纺PAN原纤维碳化的工艺规律。     

溶液喷射法制备聚丙烯腈基纳米碳纤维的研究

采用溶液喷射法制备了聚丙烯腈(PAN)纳米纤维,探讨了纺丝工艺参数对纤维形貌和直径的影响,优化了纺丝工艺,制得了直径分布为160～380 nm的PAN纳米纤维;经260℃空气氛围预氧化,900℃氮气氛围碳化,对得到的纤维的结构和形貌进行了表征,结果表明得到了平均直径为170 nm的纳米碳纤维。     

静电纺丝制备聚丙烯腈纳米碳纤维

利用静电纺丝制备连续的聚丙烯腈纳米碳纤维;介绍了静电纺丝的原理、影响静电纺丝的主要因素以及制备纳米碳纤维、纳米活性炭纤维、纳米碳纤维复合材料的方法和原理;分析了静电纺丝产率低,难以得到单向平铺的纤维等问题,影响静电纺丝的参数主要有溶液特性、纺丝工艺参数、纺丝环境参数。由静电纺丝得到纳米聚丙烯腈纤维,然后再经预氧化和碳化制备纳米碳纤维,或把纳米纤维预氧化,经活化、碳化制备纳米活性炭纤维。并指出纳米碳纤维具有巨大的潜在应用空间。     

干喷湿纺法制备T700级聚丙烯腈基碳纤维

采用丙烯腈、氨化试剂A、丙烯酸甲酯为聚合单体,以偶氮二异丁腈为引发剂,在溶剂二甲基亚砜中合成了聚丙烯腈原丝纺丝液,经干喷湿纺法纺丝制得聚丙烯腈原丝,经预氧化和炭化得到了T700级高性能聚丙烯腈基碳纤维。采用扫描电子显微镜,差示扫描量热仪,电子万能材料试验机对纤维的性能进行了研究。研究了空气层距离、喷丝头长径比、凝固浴浓度、空气拉伸比对干喷湿纺法制备纤维性能的影响。在空气层距离为40mm、凝固浴浓度为70%、喷丝头长径比为10.0、空气拉伸比为1.8条件下,采用干喷湿纺法制得的T700级聚丙烯腈基原丝及碳纤维的表面光滑、无沟槽,截面形貌为圆形;原丝的拉伸强度可达8.7cN/dtex,拉伸弹性模量可达154.7cN/dtex,碳纤维的拉伸强度可达5 750MPa,拉伸弹性模量可达220GPa。     

喷丝板对干喷湿纺法聚丙烯腈基碳纤维原丝的影响

从堵孔、表面腐蚀、喷丝孔腐蚀等喷丝板质量问题出发,分析了喷丝板对干喷湿纺法聚丙烯腈(PAN)基碳纤维原丝的单丝均一性、原丝及碳纤维的性能影响程度,为提高原丝、碳纤维质量提供一定的硬件设备理论基础。     

聚丙烯腈基碳纤维的新进展

本文主要从聚丙烯腈基碳纤维的国内外发展现状,工艺技术概况和碳纤维贴片在建筑结构物的补强应用3个方面介绍了聚丙烯腈基碳纤维的新进展。     

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。     

电纺法制备TPU微/纳米纤维的研究进展

本文介绍了电纺热塑性聚氨酯(TPU)制备中所涉及熔融电纺法和溶液电纺法的研究现状,并综述了电纺TPU在医用支架材料、伤口敷料、锂电池电解质、形状记忆材料、吸声材料、压阻敏感性材料方面的应用研究进展。     

聚丙烯腈基碳纤维综述

对国内外聚丙烯腈基碳纤维的发展历史作了评述,重点对世界聚丙烯腈基碳纤维发展最新趋势作了介绍,并提出了作者对发展我国碳纤维的建议     

对制备聚丙烯腈基高模量碳纤维的研讨

通过实验证实了用改变石墨化条件和石墨化炉的方法,可制得国产高模量(>400GPa)PAN基碳纤维     

Fabrication of Au/PVP nanofiber composites by electrospinning

Gold nanoparticles prepared by trisodium citrate reduction of HAuCl₄ in poly(vinylpyrrolidone) (PVP) ethanol solution were dispersed into PVP nanofibers by electrospinning. The optical property of Au nanoparticles before and after electrospinning was measured by UV‐Vis. The morphology and distribution of gold nanoparticles in PVP nanofibers were observed by transmission electron microscopy (TEM). The influence of the amount of Au added to and the concentration of PVP in electrospinning solution over the morphology of Au/PVP nanofibers were studied. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

静电纺丝制备聚丙烯腈纳米纤维及其预氧化

利用聚丙烯腈／二甲基甲酰胺纺丝溶液由静电纺丝制备了聚丙烯腈纳米纤维,纳米纤维的直径在220～760nm。随着聚合物溶液浓度和纺丝施加电压的升高,纳米纤维的直径变大。采用热分析和热重分析研究了纳米纤维的热性能,还用红外光谱对纳米纤维预氧化过程分子化学结构的变化进行了表征,结果表明,纳米纤维有一个很尖锐的放热峰,是聚丙烯腈均聚物典型的放热峰。随着预氧化温度的升高,纤维的内部分子结构发生了变化,表现在红外光谱上最突出的是C≡N在2243～2241cm^-1峰的降低,以及C—H在1684cm^-1峰的降低。     

静电纺丝过程中的非稳定性研究

通过静电纺聚丙烯腈纳米纤维,研究了静电纺丝过程中的非稳定性。结果表明:静电纺丝电压和接受距离是影响静电纺丝过程中的非稳定性因素,电压和接受距离增大,纳米纤维摆动加大,电压增加到一定量后,纳米纤维的摆幅在一定范围内,不会无限扩大,趋于一个固定值,接收距离超过一定范围后,纳米纤维出现不规则扰动,出现彼此缠绕。     

Fabrication of continuous nanofiber yarn using novel multi‐nozzle bubble electrospinning

A novel multi‐nozzle bubble electrospinning apparatus, including spinning unit, metering pump, constant flow pump, metal funnel and yarn winder, was designed for the preparation of continuous twisted polyacrylonitrile nanofiber yarns, and the principle of nanofiber yarn spinning was studied. An innovative spinning unit consisting of nozzle and air chamber was used to improve the production of nanofibers. Double conjugate electrospinning was developed using two pairs of oppositely charged spinning units to neutralize the charges. The effects of applied voltage, air flow rate, overall solution flow rate and funnel rotary speed on the fiber diameter, production rate and mechanical properties of the nanofiber yarns were analyzed. Nanofibers could be aggregated stably and bundled continuously, then twisted into nanofiber yarns uniformly at an applied voltage of 34 kV, air flow rate of 1200 mL min^?1 and overall solution flow rate of 32 mL h^?1. With an increase in the funnel rotary speed, the twist angle of the nanofiber yarns gradually increased when the take‐up speed was constant. The yarn tensile strength and elongation at break showed an increasing trend with increasing twist angle. Nanofiber yarns obtained using this novel method could be produced at a rate from 2.189 to 3.227 g h^?1 with yarn diameters ranging from 200 to 386 µm. Nanofiber yarns with a twist angle of 49.7° showed a tensile strength of 0.592 cN dtex^?1 and an elongation at break of 65.7%. © 2013 Society of Chemical Industry     

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     

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。     

ZnO微／纳米纤维的静电纺丝及其表征

以聚乙烯吡咯烷酮(PVP)为络合剂与醋酸锌[Zn(CH3COO)2]反应制得前驱体溶液,用静电纺丝法制备了PVP／Zn(CH3COO)2纤维,经煅烧得到具有微孔结构的氧化锌(ZnO)微／纳米纤维。对所制备纤维分别采用差热-热重分析、红外光谱分析、X射线衍射分析、扫描电镜等手段进行了表征。结果表明: PVP/Zn(CH3COO)纤维表面光滑,直径约300-700 nm,经700℃煅烧后,可得到ZnO微／纳米纤维。     

Study of electrospun polyacrylonitrile fibers with porous and ultrafine nanofibril structures: Effect of stabilization treatment on the resulting carbonized structure

Electrospun polyacrylonitrile (PAN)-based carbon nanofibers (CNFs) with high surface area have been of promising interest because of their potential for applications in various fields, especially energy devices. In this study, PAN nanofibers with porous and ultrafine nanofiber structures were prepared by electrospinning PAN/poly(vinyl pyrrolidone) (PVP) immiscible solutions and then selectively removing the PVP component from the electrospun PAN/PVP bicomponent nanofibers. The chemical reaction and microstructure of the PAN fibers with porous and ultrafine nanofibril structures in the stabilization process were investigated. The results revealed the effects of PAN fibers with porous and ultrafine nanofibril structures on the crosslinking reaction, microstructure, and morphology during the stabilization process. According to the in situ Fourier transform infrared spectroscopy results, the intermolecular and intramolecular reactions of the nitrile group for the PAN fibers with ultrafine nanofibril structures exhibited slower reaction rates than those for the neat PAN fibers during stepwise and isothermal heating. Selecting a good stabilization temperature for ultrafine PAN-crosslinked nanofibrils can enhance the surface area and carbonized structure of CNFs. The possible applications of CNFs with porous and ultrafine nanofibril structures in supercapacitors were also evaluated. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48218.