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。     

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。     

电纺法制备聚丙烯腈基纳米碳纤维

用电纺法制备了聚丙烯腈（PAN）纳米纤维,用场发射扫描电镜（FESEM）对其形态进行了研究,讨论了不同工艺参数对纤维直径和分散形态的影响。结果发现,纤维直径随着浓度的增加而增大,随着电压升高而减小,接收距离和溶剂类型对纤维直径的影响不大。将形态最好的纤维在240℃下进行活化处理,然后将活化处理过的纤维在氮气氛中煅烧,用FESEM观察了煅烧的纤维直径及形态的变化,红外（IR）分析了纤维化学结构的变化,证实了经900℃煅烧后的纤维为碳纳米纤维。     

Electrospun polyacrylonitrile nanofibers modified by quaternary ammonium salts

Electrospinning from a capillary is one of the methods for the production of nanofibers. The specific properties of such fibers result first of all from their large specific surface and the high porosity of the fiber mat. This article presents a process for producing functional nanofibers with antimicrobiological properties by electrospinning from polyacrylonitrile/dimethyl sulphoxide solution containing a bioactive agent based on quaternary ammonium salts (N, N, n, n,‐didecyl‐N,N‐dimethylammonium chloride, Bis‐(3‐aminopropyl)‐dodecylamine) and 2‐propanol. The structure of the nanofibers obtained and their antimicrobial activity are investigated. A 5 wt % addition of bioactive preparation to the polymer solution (concentration of active substance in solution about 1.5 wt %) makes it possible to obtain fibers showing good bactericidal properties. After 6 h in contact with these fibers, Escherichia coli are eliminated to a level of 99.84% and Staphylococcus aureus to 99.99%. The IR spectrophotometric measurements do not indicate a residue of solvent in the bioactive nanofibers and show an increase in content of CH and CH₂ groups in relation to the pure nanofibers, which is connected with the presence of the biocide. Their degree of crystallinity determined by the X‐ray scattering method is 44.4%. The nanofibers obtained can be designed for medical and filtration applications. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

电纺聚丙烯腈基碳纳米纤维在超级电容器中的应用

静电纺丝法制备聚丙烯腈（PAN）基纳米纤维具有较大的比表面积、较高的机械强度、优异的纳米结构及良好的化学稳定性。以PAN纳米纤维为基础,进行多方位设计与合成的电极材料在超级电容器中表现出优异的电化学性能,具有广阔的应用前景。本文根据电极材料分类,主要综述了近年来PAN基多孔结构电极材料、杂原子掺杂电极材料以及与碳系材料、导电聚合物、金属氧化物复合等电极材料的研究进展;讨论了电极材料的结构特征、制备方法及其提高电化学性能的原理;最后指出了上述研究中存在的问题,并对未来PAN基电极材料在超级电容器的发展前景进行了展望。     

Fundamental parameters affecting electrospinning of PAN nanofibers as uniaxially aligned fibers

Electrospinning with a collector consisting of two pieces of electrically conductive substrates separated by a gap has been used to prepare uniaxially aligned PAN nanofibers. Solution of 15 wt % of PAN/DMF was used tentatively for electrospinning. The effects of width of the gap and applied voltage on degree of alignment were investigated using image‐processing technique by Fourier power spectrum method. The electrospinning conditions that gave the best alignment of nanofibers for 10–15 wt % solution concentrations were experimentally obtained. Bundles like multifilament yarns of uniaxially aligned nanofibers were prepared using a new simple method. After‐treatments of these bundles were carried out in boiling water under tension. A comparison was made between the crystallinity and mechanical behavior of posttreated and untreated bundles. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4350–4357, 2006     

Preparation and properties of electrospun PAN/Fe3O4 magnetic nanofibers

Polyacrylonitrile (PAN)/Fe₃O₄ composite nanofibers were prepared via the electrospinning of the PAN spinning solutions with magnetite Fe₃O₄ nanoparticles. The experimental results showed that the morphology and diameter of the nanofibers strongly depended upon concentrations of PAN and salt additives in the spinning solutions. A suitable PAN concentration and LiCl additives could effectively prevent the occurrence of beads in the electrospinning process and affected the diameters of the electrospun nanofibers. The breaking strength and breaking strain decreased when the magnetite Fe₃O₄ nanoparticles were incorporated. The prepared PAN/Fe₃O₄ nanofibers were superparamagnetic at room temperature. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

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.     

Piezoelectric electrospun polyacrylonitrile with various tacticities

Electrospinning of urea clathrate polymerized polyacrylonitrile (PAN) with isotacticity 25% and 52% was achieved in N,N-dimethylformamide (DMF) at room temperature. Although the molecular weights of the 25% and 52% were found to be comparable by size exclusion chromatography, creation of uniform nanofibers with comparable diameters (average of ~450 nm) required concentrations of 5 % w/v and 3.5% w/v, respectively. X-ray diffraction (XRD) analysis demonstrated that the polymer retained semicrystalline structure and suggested that crystallinity was correlated with increasing isotacticity. Fourier transform infrared spectroscopy (FTIR) also confirmed increased crystallinity as compared to commercially purchased free-radical polymerized PAN due to a shift in the ~1250 cm⁻¹ methine peak. Periodic semistatic normal load piezoelectric testing of the electrospun isotactic PAN samples also exhibited an average of ~30% of the piezoelectric response of electrospun (65:35) poly(vinylidene fluoride-trifluoroethylene) (PVDF-TrFE), a current gold standard for piezoelectric polymers, whereas commercially purchased free-radical polymerized PAN exhibited no observable piezoelectric response. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47530.     

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。     

导电聚合物纳米纤维的成型

系统论述了纳米纤维成型加工新方法和导电聚合物纳米级长丝、原纤及纳米线的成型 ,提出了纳米纤维未来的潜在研究方向。指出静电纺丝法可制得导电聚合物纳米长丝 ,其直径取决于纺丝工艺参数 ;模板合成法可制得导电聚合物纳米原纤及其取向阵列 ,其直径及长度与所用模板孔径及厚度一致 ;电化学合成法可制得聚苯胺和富勒烯衍生物掺杂聚苯胺的纳米线及其电接触性良好的二维、三维非周期纳米网络。聚苯胺长丝的最小直径已控制在 1 0 0nm以下 ,聚苯胺分别与聚氧乙烯和聚苯乙烯形成的共混纤维最小直径分别为 950nm和 72nm ,聚吡咯原纤直径可达 30nm。导电聚合物纳米纤维的电导率随直径下降而急剧上升 ,展示出诱人的性能及应用前景     

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。     

静电纺丝制备纳米纤维的进展及应用

简述了静电纺丝的制备原理和影响静电纺丝纤维成形的主要工艺因素;介绍了静电纺丝法制备高分子聚合物、生物大分子、无机物纳米纤维的最新进展,以及这些纳米纤维在过滤、传感器、超疏水性材料、生物医用功能材料、纳米模板等领域的应用;指出静电纺丝制备纳米连续长丝技术亟待发展。     

螺纹式喷头制备PAN纳米纤维及其空气过滤性能

以聚丙烯腈(PAN)为纺丝液,采用自主设计研发的螺纹式喷头静电纺丝装置制备了幅宽为600 mm的纳米纤维膜。通过扫描电镜和孔径测定仪考察了纤维形貌以及直径分布,并测试了纳米纤维膜对0.26μm氯化钠粒子的过滤性能。结果表明:纤维的平均直径为138 nm,平均孔径为1.98μm,纤维膜平均厚度为0.025 mm;PAN纳米纤维膜过滤效率为99.899%,滤阻为280.9 Pa。     

Effects of some electrospinning parameters on morphology of natural silk‐based nanofibers

Natural silk, from Bombyx mori solutions were electrospun into nanofibers, with diameters ranged from 60 to 7000 nm. The effects of electrospinning temperature, solution concentration and electric field on the formation nanofibers were studied. Optical and scanning electron microscope were used to study the morphology and diameter of electrospun nanofibers. It was observed that the nanofibers became flattened with ribbon‐like shape with increasing the electrospinning temperature. The nanofiber diameter increases with the increase in the concentration of silk solution at all electrospinning temperature. With increasing the voltage of electric field at 50°C, morphology of the nanofibers changes from ribbon‐like structure to circular cross section. Referring to the literature the probable mechanism responsible for the change of morphology is pointed out. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Apparatus for preparing electrospun nanofibers: designing an electrospinning process for nanofiber fabrication

Nanofibers are widely used in a range of material applications, such as filter media, biosensors, military protective coatings, three‐dimensional tissue scaffolds, composites, drug delivery, wound dressings and electronic devices. To fabricate nanofibers with desired physical and chemical functions, a variety of electrospinning processes have been introduced using specially designed collectors, microelectromechanical system (MEMS) nozzle tips and auxiliary electrodes to stabilize the spin jets. However, the development of new electrospinning processes continues in the search for ‘tailor‐made’ nanofibers, in which parameters such as the fiber orientation and three‐dimensional structure are ultimately controllable. This paper discusses recently suggested electrospinning methods that are designed to impart specific functionality. It also details the correlations between applied processing parameters and the obtained physical properties of electrospun fibers. Finally, future design directions are suggested for developing an electrospinning apparatus capable of producing optimally structured nanofibers. Copyright © 2007 Society of Chemical Industry     

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。     

静电纺丝纳米纤维的制备工艺及其应用

简述了静电纺丝制备纳米纤维的原理;探讨了静电纺丝电压、流速、接收距离、溶剂浓度等工艺条件;介绍了同轴静电纺丝制备皮芯结构的超细纤维及中空纤维技术以及静电纺丝纳米纤维毡在生物医药方面的应用。指出静电纺丝纳米纤维材料在生物医用方面具有广阔的应用前景,进一步实现低压纺丝、开发无毒溶剂,控制同轴静电纺丝纳米纤维的释放性能是今后静电纺丝的研发方向。     

静电纺丝纳米纤维的新进展和未来动向

综述了日本和欧美静电纺丝纳米纤维技术和制品的新进展、已产业化的品种和正在研发的多样新品种和新用途,指出未来的研发方向和动向.     

Fabrication and characterization of carbon nanofibers from polyacrylonitrile/pitch blends

Continuous carbon nanofibers had been widely studied based on different processing methods and precursors. Especially, electrospinning was introduced as a versatile method for fabricating ultrathin fibers. However, as the limitation of precursor, pitch had not been well studied due to its viscosity and miscibility problem. A comprehensive study on the electrospinning of the blends [pitch and polyacrylonitrile (PAN)] was explored. Thermodynamic miscibility was studied by using differential scanning calorimeter. Fourier transfer infrared spectroscopy was used to show interaction and potential reaction between pitch and PAN molecules. Finally, smooth, continuous, and cylindrical carbon nanofibers were successfully fabricated by electrospinning technique. Based on Raman analysis result, the addition of pitch enhanced the carbon crystallite which improved the overall electrical conductivity and modulus of nanofibers. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45388.