静电纺丝制备锂离子电池负极用多层柔性聚丙烯腈/沥青碳纤维复合材料的方法

正本发明属于石油化工和碳纳米交叉领域,涉及一种静电纺丝制备锂离子电池负极用多层柔性聚丙烯腈/沥青碳纤维复合材料的方法。首先通过静电纺丝制备聚丙烯腈纤维,脱油和聚乙烯吡咯烷酮的混合溶液再经静电纺丝制备混纺纤维并收集在聚丙烯腈纤维上,重复上述步骤即可制得具有多层结构的聚丙烯腈/沥青复合纤维材料,经过预氧化和碳化,制得多层柔性聚丙烯腈/沥青碳纤     

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。     

聚乙二醇对碳纤维电极材料性能的影响

以聚乙二醇为改性剂,采用静电纺丝法制备聚丙烯腈纤维。经预氧化、碳化过程制备了聚丙烯腈基碳纤维。用SEM、XRD等手段表征了碳纤维的微观形貌及结构。用XPS测试表征了碳纤维表面元素含量。用循环伏安测试法测试碳纤维电极材料的电化学性能。实验结果表明,当聚乙二醇加入量为4％时,得到的碳纤维电极材料电容性能最佳,其比电容值达到126．84F／g。     

一种聚丙烯腈基中空碳纤维原丝及其制备方法

本发明涉及一种聚丙烯腈基中空碳纤维原丝及其制备方法。本发明的聚丙烯腈基中空碳纤维原丝可用于聚丙烯腈基中空碳纤维的制备。采用含衣康酸的丙烯腈二元共聚体系,或含衣康酸与丙烯酸甲酯的丙烯腈三元共聚体系湿法纺丝工艺配合圆弧狭缝喷丝板纺丝,可以得到多丝束中空碳纤维原丝、该原丝的外径尺寸与结构符合常规预氧化碳化工艺对原丝纤维的要求、纤维表面存在沟槽结构有利于复合材料界面性能的提高。     

聚丙烯腈基超细碳纤维毡的制备及其表征

采用静电纺丝法制备了不同黏均分子质量(Mη)的聚丙烯腈(PAN)超细纤维毡,并通过280℃预氧化和900℃碳化进一步制备超细碳纤维毡。讨论了Mη对纤维制备的影响,发现PAN的Mη大于3×105则不利于静电纺丝,小于5×104则纤维毡发脆,无法进一步加工处理成碳纤维毡。用场发射扫描电镜、红外光谱、X-射线衍射对纤维毡进行表征,结果表明:随着PAN相对分子质量的升高,碳纤维的直径和得率增大。此外,抗拉强度测试表明:随着相对分子质量的增大,超细碳纤维毡的抗拉强度增加。     

预氧化温度对静电纺Co/C复合纳米纤维形貌与结构的影响

通过调节静电纺丝过程环境因素制备了CoAc_2/PAN前驱体纤维,再经过热处理得到Co/C复合纳米纤维,分析了预氧化温度对纤维形貌与结构的影响。研究结果表明:当预氧化温度为160℃时,纤维中的PAN未形成稳定的耐热梯形结构,在碳化时纤维扭曲,生成枝节状物质;当预氧化温度为230℃时,碳化后可得到表面光滑、均匀,结构完好的Co/C复合纳米纤维;当预氧化温度为300℃时,纤维中的聚合物大分子遭到破坏,导致后续的碳化结晶过程无法正常进行,纤维形成颗粒聚集态。     

纺丝、预氧化和碳化条件与PAN基碳纤维性能的关系

本文采用干湿法纺制共聚丙烯腈纤维,并进行预氧化,碳化制成碳纤维。对纺丝、预氧化、碳化等工艺过程进行不同条件的实验,探讨了工艺条件与碳纤维性能之间的关系。     

静电纺聚丙烯腈基超细碳纤维的研究

利用静电纺丝设备,在仅改变滚筒收集装置的转速的条件下,制得不同有序度的聚丙烯腈超细纤维毡,利用扫描电子显微镜来观察纤维的直径及形态,得出纤维排列的有序度随滚筒转速的增加而提高。再将制得的聚丙烯腈纳米纤维毡在不同温度下预氧化,最后经过碳化,得到超细碳纤维毡,分析在不同滚筒转速下收集的不同有序度的超细碳纤维毡的力学性质。通过拉伸试验,得出随着转速的增加,纤维毡的拉伸强度有所增加。     

聚丙烯腈前驱体的优化及其中空碳纳米纤维的制备

为制备力学性能较好的聚丙烯腈(PAN)中空碳纳米纤维,首先通过正交试验研究了PAN聚合参数对聚合反应的影响,然后选取适宜于纺丝的PAN进行同轴静电纺丝、预氧化、碳化,对得到的中空碳纳米纤维进行表征。结果表明,引发剂用量(A)对PAN相对黏均分子质量的影响最大;第二单体衣康酸浓度(B)对PAN环化放热的影响最大;第三单体丙烯酸甲酯浓度(C)对PAN聚合收率的影响最大。SEM分析结果表明,PAN中空碳纳米纤维横截面具有明显的中空结构,纤维表面较为致密。BET测试结果表明,PAN中空碳纳米纤维的孔容为0. 069 69 cm3/g,比表面积为55. 719 m2/g。     

聚丙烯腈纤维纺丝油剂对碳纤维性能的影响

研究了3种聚丙烯腈纤维油剂对原丝纺丝、预氧化和碳化过程的影响。结果表明:纺丝上油率与上油浓度成正比,二油工序纤维上油率受油剂浓度影响大;油剂对预氧化反应有阻碍作用,上油率越大,阻碍作用越大,但其可使预氧化过程易于控制;使用油剂可提高碳纤维的力学性能,与未上油原丝制得的碳纤维相比,上油率为1.0%时,3种油剂使碳纤维拉伸强度分别提高了8.81%、9.85%和11.74%。     

聚乙烯醇静电纺丝纳米纤维的制备及形貌研究

利用静电纺丝技术制备聚乙烯醇（PVA）纳米纤维材料,通过正交试验调节制备过程中纺丝电压、纺丝距离和纺丝溶液浓度等工艺参数,探究其对PVA纳米纤维直径大小、直径分布以及纤维形貌的影响。结果表明,影响纳米纤维形貌的主要因素排序是纺丝溶液浓度＞纺丝距离＞纺丝电压,并确定最优水平组合为纺丝电压为20 kV,PVA纺丝溶液浓度为6 %(质量分数,下同),纺丝距离为12 cm。     

静电纺丝法制备碳纳米纤维及其应用

碳纳米纤维由于因其比表面积大、导电和导热性好,被广泛用于催化剂载体、吸附和储能材料。静电纺丝是制备一维纳米纤维直接、有效的方法,在介绍静电纺丝的基本原理和工艺影响因素的基础上,综述了电纺碳纳米纤维的特性及其应用。     

一维多孔碳纳米纤维的可控制备及电化学性能研究

利用静电纺丝技术,将聚苯乙烯(PS)、聚甲基丙烯酸甲酯(PMMA)与聚丙烯腈(PAN)纺丝原液混合,电纺得到高分子纤维膜,再结合高温碳化技术得到一维多孔PAN基碳纤维。通过X射线衍射(XRD)、差热热重(TG-DSC)、傅里叶变换红外光谱(FT-IR)和扫描电子显微镜(SEM)等对所制备电极材料的结构和形态进行了系统表征,同时将其组成三电极体系研究电化学性能。结果表明:当纺丝原液中nPAN∶nPS=60∶1时,其在电流密度为0.5 A/g下的比电容值为339.23 F/g;当纺丝原液中n PAN∶n PMMA=40∶1时,其在电流密度为0.5 A/g下的比电容值为314.54 F/g,比纯PAN基碳纤维的比电容值有所上升;同时,在循环充放电2000圈后,初始比电容的保持率分别达95.5%和94.6%,展示出了良好的电容性能和循环性能。     

Electrospun preparation of microporous carbon ultrafine fibers with tuned diameter,pore structure and hydrophobicity from phenolic resin

Microporous carbon ultrafine fibers with different diameter were prepared by electrospinning from resole-type phenolic resin, followed by heat curing and one-step carbonization, and their adsorption performance for benzene and water was evaluated. Average diameter of as-spun fibers changed from 1.1 to 0.33 μm with increasing dimethylformamide content in the spinning solution, caused by more fiber divisions. The carbon ultrafine fibers with smaller diameter exhibited enhanced benzene adsorption and diminished water adsorption due to improved specific surface area, micropore volume and hydrophobicity. In addition, the relatively developed hydrophobicity of the prepared carbon ultrafine fibers resulted in much higher adsorption tendency for benzene over water, in comparison to common polyacrylonitrile-based electrospun activated carbon nanofibers.     

Fabrication and characterization of carbon nanofibers with a multiple tubular porous structure via electrospinning

Carbon nanofibers with a multiple tubular porous structure were prepared via electrospinning from a polymer blend solution of polyacrylonitrile (PAN) and polylactide (PLA) followed by carbonization. The electrospun composite nanofibers underwent pre-oxidization and carbonization, which selectively eliminated PLA phases and transformed the continuous PAN phase into carbon, thereby porous structure formed in the carbon nanofibers. The morphologies of as-spun, pre-oxidized and carbonized nanofibers were studied by scanning electron microscope (SEM) and transmission electron microscopy (TEM). It was found that carbon nanofibers with an average diameter about 250 nm and a multiple tubular porous structure were obtained. The chemical changes during thermal treatment were studied by Fourier transform infrared spectrometer (FTIR), Raman spectra, differential thermal analysis (DTA) and thermogravimetric analysis (TG). The results showed that PLA phases were effectively removed and the continuous PAN phase was completely carbonized. The obtained carbon nanofibers had more disordered non-graphitized structures than non-porous nanofibers.     

Fabrication and Thermal Dissipation Properties of Carbon Nanofibers Derived from Electrospun Poly(Amic Acid) Carboxylate Salt Nanofibers

Polyimides (PIs) possess excellent mechanical properties, thermal stability, and chemical resistance and can be converted to carbon materials by thermal carbonization. The preparation of carbon nanomaterials by carbonizing PI‐based nanomaterials, however, has been less studied. In this work, the fabrication of PI nanofibers is investigated using electrospinning and their transformation to carbon nanofibers. Poly(amic acid) carboxylate salts (PAASs) solutions are first electrospun to form PAAS nanofibers. After the imidization and carbonization processes, PI and carbon nanofibers can then be obtained, respectively. The Raman spectra reveal that the carbon nanofibers are partially graphitized by the carbonization process. The diameters of the PI nanofibers are observed to be smaller than those of the PAAS nanofibers because of the formation of the more densely packed structures after the imidization processes; the diameters of the carbon nanofibers remain similar to those of the PI nanofibers after the carbonization process. The thermal dissipation behaviors of the PI and carbon nanofibers are also examined. The infrared images indicate that the transfer rates of thermal energy for the carbon nanofibers are higher than those for the PI nanofibers, due to the better thermal conductivity of carbon caused by the covalent sp² bonding between carbon atoms.     

Carbon nanonodules fewer than ten graphenes thick grown on aligned amorphous carbon nanofibers

A novel structure of carbon nanonodules containing fewer than 10 layers graphene has grown on amorphous carbon nanofibers by carbonization-induced self-assembly. It is found that a successive processes containing pre-oxidation in air at 220 °C and carbonization in a high vacuum (1 × 10⁻⁴ Pa) at 750 °C are necessary for the fabrication of the carbon nanonodules. Possible mechanism for the evolution of amorphous nanofibers to carbon nanonodules is presented. It is also found that the temperature of the collector during electrospinning of the fiber and the pressure of carbonization are critical factors for growth of the nanonodules. With these mechanisms, carbon nanonodules can be selectively grown on the prepared amorphous carbon nanofibers using pre-oxidation and carbonization of an electrospun glycerol–polyacrylonitrile fiber.     

明胶超细纤维成形研究

以去离子水为溶剂,采用静电纺丝工艺制备明胶超细纤维。系统探讨了温度、浓度及电纺工艺参数对明胶电纺纤维成形的影响。结果表明：纺丝环境温度的升高有利于获得平均直径较小的纤维;随着明胶溶液质量分数从25％下降到15％,所得明胶纤维平均直径从266．5nm下降到167．7nm,其直径分布也逐渐变窄;随着静电纺丝电压升高,所得纤维直径降低;改变静电纺丝接收距离,所得的纤维直径及其分布均无太大变化。考察了纺丝液中的离子对明胶电纺纤维形貌的影响,发现随着添加的NaGl浓度的增大（0．01～0．5mol／L）,所得明胶纤维的直径呈线性增加（196～390nm）,与纯明胶电纺相比,离子的加入使所得纤维直径分布变宽。     

Novel Pd-carrying composite carbon nanofibers based on polyacrylonitrile as a catalyst for Sonogashira coupling reaction

Novel Pd-carrying composite carbon nanofibers based on polyacrylonitrile were prepared by electrospinning and carbonization process. The catalytic activities of the composite nanofibers were tested with a Sonogashria coupling reaction of iodobenzene and phenylacetylene in liquid-phase. Transmission electron microscope and X-ray diffraction analyzer were used to characterize the nanofibers and the metal nanoparticles on the fibers; gas chromatograph and nuclear magnetic resonance spectroscopy were used to characterize the product of the testing reaction. The results first showed that the catalyst not only had a high catalytic activity, but also had good leaching-resistance, retrieval and reusability for the Sonogashira reaction.