共查询到19条相似文献,搜索用时 147 毫秒
1.
溶剂及溶液中无机盐对电纺纤维的影响 总被引:4,自引:0,他引:4
采用二甲基乙酰胺(DMAc)与丙酮的混合溶剂,对醋酸纤维素(SCA)电纺过程中溶液性质对纤维直径及形态的影响进行研究。不同的溶液性质具体表现为不同的溶度参数、黏度、表面张力、挥发度等,而纤维直径的细化是以上参数共同作用的结果。而本文中,由于丙酮对溶液的挥发度起了决定性作用,使电纺纤维的直径的改变受其影响最大。当DMAc∶丙酮的混合比为20∶80时,纤维表面会充满凹陷的小孔。另外,无机盐的加入也会导致溶液黏度、表面张力呈先下降后上升的趋势,电导率和电荷密度随之上升。在其他条件一定时,SCA/LiCl体系的纤维直径要小于SCA/CaCl2体系;无机盐含量超过2%时,纤维直径会有一定程度的增加。 相似文献
2.
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。 相似文献
3.
《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
4.
利用静电纺丝技术制备了一种聚丙烯腈(PAN)/氧化铁(Fe_2O_3)纳米粒子复合纳米纤维。不同分子量的PAN得到不同直径的纤维薄;将PAN的N,N-二甲基甲酰胺溶液(DMF)与纳米Fe_2O_3混合得到PAN/Fe_2O_3溶液,然后利用静电纺丝技术制备PAN/Fe_2O_3纳米粒子复合纳米纤维;将静电纺丝制备的PAN纳米纤维膜与氯化铁(FeCl_3)溶液在不同p H条件下水热合成PAN/Fe_2O_3纳米粒子复合纳米纤维。采用扫描电子显微镜(SEM)、热重分析仪(TGA)对纳米纤维膜进行表征。结果表明:静电纺丝制备的PAN纳米纤维在水热条件下可以一定程度上克服Fe_2O_3纳米粒子易团聚问题。 相似文献
5.
6.
7.
8.
采用静电纺丝技术制备了铈掺杂钇铝石榴石(cerium doped yttrium aluminium garnet,YAG:Ce)纳米纤维,利用扫描电镜观测了电纺丝纤维的微结构与形貌,利用荧光光谱仪表征了YAG:Ce电纺丝纤维的荧光性能。结果表明:在还原气氛下热处理制备YAG:Ce电纺丝纳米纤维时,在纳米纤维表面出现了一层直径为50~100 nm的球形凸起物。相比于空气气氛中,在还原气氛中热处理制备YAG:Ce纳米纤维的荧光发射强度显著增强。并且随着Ce~3+掺杂含量增加,YAG:Ce电纺丝纤维的荧光发射带发生红移。 相似文献
9.
《塑料》2017,(3)
以硝酸锌(Zn(NO_3)_2)、硝酸铝(Al(NO_3)_3)为原料,通过水热合成法在二氧化钛(TiO_2)晶须表面包覆掺铝氧化锌(AZO)导电膜层,制备导电二氧化钛晶须(AZO@TiO_2)。将AZO@TiO_2添加到聚丙烯腈(PAN)纺丝液中,经湿法纺丝制得PAN/AZO@TiO_2复合导电纤维。分别采用扫描电子显微镜、X射线衍射仪、热重分析仪、Electrometer电阻测试仪和万能拉伸试验机分剐对复合导电纤维的结构性能进行表征,结果表明:当AZO@TiO_2掺杂量为30%时,PAN/AZO@TiO_2复合导电纤维电阻值达到15.7 MΩ,拉伸强度最大达到5.5 MPa,断裂伸长率最大为19.7%。 相似文献
10.
11.
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. 相似文献
12.
Preparation, structure and supercapacitance of bonded carbon nanofiber electrode materials 总被引:1,自引:0,他引:1
Interconnected carbon nanofibrous membranes were prepared by conventional electrospinning and bicomponent electrospinning to produce polyvinylpyrrolidone (PVP)/polyacrylonitrile (PAN) blend nanofibers and PVP/PAN side-by-side bicomponent nanofibers, followed by a direct pyrolysis treatment. The inter-fiber connection was highly affected by the PVP/PAN ratio and electrospinning method. The carbon nanofibers prepared from the side-by-side PVP/PAN nanofibers were found to have higher electrochemical capacitance than those from the PVP/PAN blend nanofibers. 相似文献
13.
Co-axial electrospinning with sodium thiocyanate solution for preparing polyacrylonitrile nanofibers
A modified co-axial electrospinning process including electrolyte solution as sheath fluid for preparing high quality polymer
nanofibers is investigated. A series of polyacrylonitrile (PAN) nanofibers were fabricated utilizing the modified process
with sodium thiocyanate solutions in N, N-dimethylacetamide (DMAc) as sheath fluids. Field-emission scanning electron microscopy
results demonstrated that the sheath sodium thiocyanate solutions had significant influence on the quality of PAN nanofibers.
High quality PAN nanofibers in terms of fiber diameters and their distributions, surface morphology and structure have been
successfully produced. The diameters of nanofibers (D, nm) could be manipulated simply by adjusting the concentrations of sodium thiocyanate (C, mg ml-1) in the sheath fluids with a scaling law of D = 324 C
-0.1806. The mechanism about the influence of sodium thiocyanate solutions on the formation of PAN fibers is discussed and it is
felt that co-axial electrospinning with electrolyte solution is a facile process for achieving high quality polymer nanofibers. 相似文献
14.
Multiwalled carbon nanotube/Polyacrylonitrile (MWNT/PAN) composite nanofibers were prepared by electrospinning technique,
whereby functionalized MWNTs (F-MWNTs) and pristine MWNTs (P-MWNTs) were used as reinforcing materials. The F-MWNTs were functionalized
by Friedel-Crafts acylation, which introduced aromatic amine (COC6H4-NH2) groups onto the sidewall. The diameter range of the PAN nanofibers was 400-100 ± 50 nm. The beads formation was also observed
when the amounts of MWNTs were increased in the PAN solution. The bead formation in F-MWNT/PAN composite nanofibers was less
as compared to P-MWNT/PAN. The MWNTs were embedded within nanofibers and were well oriented along the nanofiber axis, as confirmed
by transmission electron microscopy. The mechanical and thermal properties of the PAN nanofibers were improved by the incorporation
of MWNTs. 相似文献
15.
The effect of NaSCN salt on the spinnability of polyacrylonitrile (PAN) solutions, its resulting morphology, mechanical property, and the flame resistance of the resulting electrospun nanofibers were studied. The intent was to develop a method to produce nanosized carbon fiber precursors with good properties. Electrospun PAN nanofibers from 9.7–9.9 wt% PAN/sodiumthiocyanate (NaSCN) (aq)/Dimethylformamide (DMF) solutions with 1.0–2.9 wt% NaSCN (aq), and 10–15 wt% PAN/DMF solutions without salt exhibited good spinnability and morphology with no beading in the range of applied voltage (18–20 kV) and take‐up velocity (9.8–12.3 m/s). The relatively high take‐up velocity produced good yarn alignment. The diameter distributions of the PAN nanofibers containing the NaSCN salt were narrower than those of the PAN/DMF nanofibers without the salt. It was determined that the maximum content of salt for production of electrospun PAN nanofibers with good morphology was below 3.8 wt% (40 wt% based on PAN). The salt concentration can positively influence on the narrow diameter distributions of the resulting electrospun fibers. Also, it could be confirmed that the salt effect on mechanical property and flame resistance of electrospun PAN nanofibers. In particular, the elongation of the PAN nanofiber with 2.9 wt% NaSCN (aq) was significantly increased as much as 186% compared with that of 10 wt% PAN nanofiber without the salt. The flame resistance and mechanical properties of the stabilized PAN nanofibers with NaSCN (aq) increased after oxidization process. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers. 相似文献
16.
Random and alternating poly(styrene-co-maleic anhydrides) (SMAs) with respective maleic anhydride (MAh) content of 32 and 48% were synthesized through radical polymerization. SMA nanofibers with diameter down to 180 nm were generated by electrospinning from solvents acetone, dimethylformamide (DMF), and their mixtures. Fiber diameter increased dramatically when the SMA concentration in the spinning solution reached to a critical point where the SMA chains are extensively entangled. The diameter of SMA nanofiber decreased with increasing DMF content in the mixture, but beads are often accompanied as DMF content is over 50%. The optimum acetone/DMF ratio was found to be 2:1, in which continuous electrospinning was achieved and bead-free nanofibers were obtained. SMA nanofibers with MAh content of 32 and 48% were crosslinked with diethyleneglycol and subsequently hydrolyzed in NaOH/EtOH to turn SMA into crosslinked sodium form SMA (SMA-Na) hydrogel nanofiber. These hydrogel nanofibers were able to retain fiber form after immersing in water for 24 h. Their water absorption ratio was up to 37.6 and 8.2 g/g in distilled water and 0.25 N NaCl aq. solution, respectively. 相似文献
17.
Xianhua Zhang Masuhiro Tsukada Hideaki Morikawa Kazuki Aojima Guangyu Zhang Mikihiko Miura 《Nanoscale research letters》2011,6(1):510
Silk sericin (SS)/silk fibroin (SF) blend nanofibers have been produced by electrospinning in a binary SS/SF trifluoroacetic acid (TFA) solution system, which was prepared by mixing 20 wt.% SS TFA solution and 10 wt.% SF TFA solution to give different compositions. The diameters of the SS/SF nanofibers ranged from 33 to 837 nm, and they showed a round cross section. The surface of the SS/SF nanofibers was smooth, and the fibers possessed a bead-free structure. The average diameters of the SS/SF (75/25, 50/50, and 25/75) blend nanofibers were much thicker than that of SS and SF nanofibers. The SS/SF (100/0, 75/25, and 50/50) blend nanofibers were easily dissolved in water, while the SS/SF (25/75 and 0/100) blend nanofibers could not be completely dissolved in water. The SS/SF blend nanofibers could not be completely dissolved in methanol. The SS/SF blend nanofibers were characterized by Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry, and differential thermal analysis. FTIR showed that the SS/SF blend nanofibers possessed a random coil conformation and ß-sheet structure. 相似文献
18.
Electrospinning is a relatively simple method to produce submicron fibers from solutions of different polymers and polymer blends. If the solution is absolutely insulating, or the applied voltage is not high enough that electrostatic force cannot overcome the surface tension, then no fiber can be produced by electrospinning; however, if some salt is added in the solution, the problem can be overcome. The effect of different salts on electrospinning of polyacrlonitrile (PAN) polymer solution was investigated in this article. The various inorganic salts used in this work include LiCl, NaNO3, NaCl, and CaCl2.The results show that when the salts were added, respectively, into different concentrations of PAN solution, the order of conductant was LiCl > NaNO3 > CaCl2 > NaCl > no salt added. Viscosity and shearing strength of electrospinning solutions are slightly affected by the adding of salts and mainly affected by the changes in concentration of PAN electrospinning solutions. The diameter of nanofibers electrospun by solutions with different salts size down as follows: LiCl > NaNO3 > CaCl2 > NaCl. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3865–3870, 2007 相似文献
19.
Poly(acrylonitrile) (PAN) was solution blended with poly(n-butyl methacrylate) (PnBMA) in various proportions. Compatibility in these blend systems was analyzed using ultrasound. The ultrasound velocity and attenuation results show that the two polymers formed a compatible blend. Viscosity and other derived parameters like free volume and internal pressure of the blends show that PAN form into an ideal blend with PnBMA in the compositions of 60 : 40 and 40 : 60. © 1994 John Wiley & Sons, Inc. 相似文献