静电纺丝法制备MWNTs／聚胺醚复合纳米纤维

摘要用静电纺丝法制备MWNTs／聚胺醚复合纳米纤维，将收集到的无纺布通过SEM观察其微观形貌，并用Image-ProPlus6．0软件测量纤维的直径；分别用TG和XRD测试了复合纤维的热性能和结晶行为。结果表明，MWNTs含量较多的纺丝溶液受到的电场力较大，比较容易得到纤维，且得到的纤维直径较细；MWNTs含量为l％时...     

MWNTs/PU复合微/纳米纤维的形态及力学性能

应用静电纺丝技术制备多壁碳纳米管/聚氨酯(MWNTs/PU)复合微/纳米纤维 , 将该复合纤维收集成无纺布薄膜 , 采用扫描电子显微镜 (SEM)和透射电子显微镜 (TEM)观察了纤维的微观形貌和结构 , 分别利用X射线衍射(XRD)和差示扫描量热法(DSC)测试了复合纤维的结晶行为及玻璃态转变温度 , 并测试了纤维薄膜的拉伸力学性能随 MWNTs含量的变化关系。结果表明 , 一定含量的 MWNTs能有效地分散于 PU 溶液中 , 并能成功地纺出 MWNTs/PU 复合微/纳米纤维。随 MWNTs在 PU 纤维中含量的增加 , 纤维的直径变细 , 复合纤维的玻璃态转变温度提高。在所研究的含量范围内 , 无纺布的拉伸强度和断裂伸长率随 MWNTs 含量的增加而有所增大。      

PAN/MWNTs纳米纤维的制备及电磁屏蔽性能研究

采用静电纺丝技术制备了聚丙烯腈/多壁碳纳米管(PAN/MWNTs)复合纳米纤维。利用红外光谱和扫描电镜分别对纳米纤维结构和形貌进行了表征分析,并用高阻仪和矢量网络分析仪分别对PAN/MWNTs纳米纤维的导电性能及电磁屏蔽性能进行了测试。结果表明,随着MWNTs含量的增加,纤维直径减小,纤维的导电性能增强;纳米纤维膜在低频段均表现良好的电磁屏蔽效果,在1～15MHz频率范围内,当碳纳米管的含量达到10%以上时,屏蔽率达到90%以上。     

MWNTs/丝素/聚酰胺共混静电纺纳米纤维毡的结构和性能

静电纺再生丝素纤雏具有在水中易溶胀、结构稳定性和力学性能差等缺陷.在前期研究聚酰胺6/66对静电纺丝素纤维的结构和性能改进效果的基础上,以多壁碳纳米管(MWNTs)增强静电纺丝素/聚酰胺6/66复合纳米纤维.研究发现,随着MWNTs含量的增加复合纤维毡的颜色由白色变成黑色,纤维直径逐渐减小,并且都在90nm以下.MWNTs的加入,还有效地提高了纤维的结晶度、热稳定性以及纤维毡的拉伸力学性能.     

磁场辅助静电纺有序PAN/PVP复合纳米纤维的制备及工艺优化

磁场辅助静电纺丝(MFAES)技术能够制备有序纳米纤维,但其参数间的匹配关系很少被系统研究。通过MFAES方法制备了有序聚丙烯腈(PAN)/聚乙烯吡咯烷酮(PVP)复合纤维,应用正交实验分析了纺丝中主要的过程参数对复合纤维直径和有序度的影响。实验表明:随着浓度增大,复合纤维的直径增大,得到复合纤维的最小直径为496nm;溶液浓度和纺丝电压是复合纤维有序度的显著影响因素,在溶液浓度为14wt%、PAN/PVP配比为80∶20、纺丝电压为12kV、磁铁间距为2cm时,复合纤维的有序度最高达95%。     

纳米Ag-聚乙烯醇缩丁醛静电纺丝复合纳米纤维的制备及性能

采用静电纺丝技术制备纳米Ag-聚乙烯醇缩丁醛（PVB）复合纳米纤维,获得一类过滤性能和抗菌性能优异的空气过滤材料。采用TEM分析纳米Ag的形貌,采用SEM、FTIR和XRD等表征手段研究纳米Ag-PVB复合纳米纤维的微观形貌、化学结构以及结晶行为,并对其空气过滤性能、透气性能和抗菌性能进行了研究。结果表明：以乙醇为溶剂,当PVB含量为10wt%、纳米Ag含量为0.25wt%时,得到的纤维尺寸均一,平均直径为542.14 nm。性能测试结果表明,纺丝最佳时间为10 min,纳米Ag-PVB复合纳米纤维对PM2.5过滤效率为99.99%,过滤阻力为16 Pa,透气率为155.0 mm/s,并且对大肠杆菌表现出优异的抗菌性能,其抑菌率为95.52%。     

多壁碳纳米管/聚乳酸复合超细纤维的制备及性能

通过静电纺丝法制备出多壁碳纳米管（MWNTs）增强聚乳酸（PLA）复合超细纤维膜。用扫描电镜、透射电镜、差示扫描量热仪、热重分析仪对MWNTs/PLA复合超细纤维进行了表征,并进行了拉伸测试。结果表明,MWNTs分散于PLA纤维中,随着MWNTs含量的增加,纤维平均直径先减小后增大,MWNTs的加入会降低PLA的结晶度...     

甲壳素纳米晶须/聚乳酸复合纤维膜的制备及表征

采用静电纺丝技术制备了甲壳素纳米晶须/聚乳酸复合纳米纤维膜并对其进行了表征分析.借助扫描电子显微镜(SEM) 及相关测试软件,测出复合纳米纤维平均直径在500～1000nm之间;当甲壳素纳米晶须含量低于7％时,对复合纳米纤维的可纺性及形貌影响较小;但当其含量高于7％时,复合纳米纤维表面变得粗糙.傅立叶红外变换光谱仪(FT-IR)和X射线衍射仪(XRD)观察分析表明,甲壳素纳米晶须已成功加入到聚乳酸纤维中.拉伸试验结果表明,当纳米晶须含量为3％时,复合膜的拉伸强度提高了63.65％,进一步增加纳米晶须含量,其增强作用呈下降趋势,甚至出现负增强.     

静电纺工艺参数对聚乳酸-茶多酚复合纳米纤维直径和形貌的影响

研究了静电纺丝工艺参数对聚乳酸(PLA)-茶多酚(TP)复合纳米纤维形貌与直径的影响,借助扫描电子显微镜(SEM)观察在不同纺丝电压、不同接收距离和不同纺丝速度条件下PLA-TP复合纳米纤维的外观形貌,通过专用软件计算纳米纤维的直径。结果表明,在本实验范围内均能得到表面光滑连续的纳米纤维,PLA-TP复合纳米纤维直径为350～800nm;纺丝电压、接收距离和纺丝速度均对纳米纤维直径和形貌有较大影响;较好的纺丝工艺条件为纺丝电压18kV、接收距离17.5cm、纺丝速度0.6～0.8mL/h。     

静电纺PA-SA/PET/MWNTs复合相变纤维的制备及储热性能研究

以聚对苯二甲酸乙二酯(PET)、棕榈酸和硬脂酸二元低共熔物(PA-SA)和多壁碳纳米管(MWNTs)为原料,通过静电纺丝的方法制备了新型的PA-SA/PET/MWNTs定形相变复合纤维。研究了强酸处理后的MWNTs对静电纺PA-SA/PET/MWNTs复合相变纤维的形貌结构和储热性能的影响。FT-IR光谱分析表明,强酸处理后在MWNTs的表面成功的引入了羧基(-COOH)官能团。SEM观察表明,随着MWNTs的加入,复合相变纤维表面沟槽变得更加明显且纤维直径明显增大。DSC分析表明了MWNTs的含量对复合相变纤维的熔化焓值和结晶焓值有一定的影响,对熔化温度和结晶温度没有显著性的影响。     

Study on morphology and characterization of poly(mphenylene isophtalamide)/multi-walled carbon nanotubes composite nanofibers by electrospinning

Electrospinning technique is the main method of preparing polymer nanofiber simply, directly and continuously at present. In this work, electrospinning blend solution was prepared by in-situ polymerization using acid-modified multi-walled carbon nanotubes (MWNTs), m-phenylenediamine (MPD) and isophthaloyl chloride (IPC). And then composite nanofibers were prepared by electrospinning. MWNTs played an important role in nanofiber's properties. The effects of MWNTs on the morphology and characterization of the MWNTs/PMIA composite nanofibers were investigated. Scanning electron microscopy (SEM), thermal gravimetric analyzer (TGA), and X-ray diffraction (XRD) were utilized to characterize the MWNTs/PMIA nanofibers morphology and properties. The experimental results indicated that the nanofibers diameter decreased and solution dynamic viscosity increased with increasing MWNTs contents. XRD data demonstrated that PMIA composite nanofibers had the same crystal type as the pure PMIA nanofiber, and crystallinity was improved with increasing MWNTs loading. Transmission electron microscopy (TEM) was used to confirm MWNTs aligned along the axis of composite nanofibers.     

Anatase TiO2 nanoparticles/carbon nanotubes nanofibers: preparation, characterization and photocatalytic properties

In the present work, we report the preparation and photocatalytic properties of hybrid nanofibers/mats of anatase TiO₂ nanoparticles and multi-walled carbon nanotubes (MWNTs) using combined sol–gel and electrospinning techniques. Poly(vinyl pyrrolidone) is used as a base polymer in the electrospinning suspension to assist the formation of nanofibers and subsequently removed by calcination. The hybrid nanofibers are characterized using XRD, Raman spectra, FT-IR, XPS, SEM, TEM and N₂ adsorption measurements. The results show that MWNTs are encapsulated by in-situ formed anatase TiO₂ nanoparticles, with chemical bonding C–O–Ti between anatase TiO₂ nanoparticles and MWNTs. Hybrid nanofibrous mats with moderate content of MWNTs (mass ratio TiO₂:MWNTs = 100:20) exhibit enhanced adsorption ability and excellent photocatalytic activity. The composition, diameter and morphology of hybrid nanofibers can be tuned by varying sol–gel formulation, electrospinning parameter and post-treatment condition. TiO₂/MWNTs hybrid nanofiber and mats have promising applications in water purification and solar cell areas.     

Electrical properties of polyaniline and multi-walled carbon nanotube hybrid fibers

We have fabricated for the first time one-dimensional multiwalled carbon nanotube (MWNT) nanocomposite fibers with improved electrical properties using electrospinning. Polyaniline (PANi) and poly(ethylene oxide) (PEO) were used as a conducting and a nonconducting matrix, respectively, for hybrid nanofibers including MWNTs. The hybrid nanofibers fabricated by electrospinning had a length of several centimeters and a diameter ranging from approximately 100 nm to approximately 1 microm. Transmission electron microscopic analysis confirmed that the MWNTs were successfully oriented along the fiber axis without any severe aggregation during electrospinning. The hybrid nanofibers showed an enhanced electrical conductance with increasing MWNT content up to 0.5 wt%, and compared to PANi/PEO fibers, they also showed a stable linear ohmic behavior. These hybrid conducting nanofibers can be applied to chemical and biosensors that require a high sensitivity.     

PA6(MWNTs)纳米纤维增强PMMA透光复合材料

以尼龙6(PA6)为载体,结合同轴共纺技术将多壁碳纳米管(MWNTs)均匀包裹在PA6/PMMA体系的芯层中,再利用热压成型技术将壳层聚甲基丙烯酸甲酯(PMMA)熔融,从而制备出PA6(MWNTs)均匀分散的增强透光复合材料.实验中分别考察不同含量的MWNTs对复合材料形貌、力学性能的影响.结果表明,采用同轴共纺工艺能...     

Mechanical properties of electrospun PVA/MWNTs composite nanofibers

Composites of polyvinyl alcohol (PVA) and multi-walled carbon nanotubes (MWNTs) were prepared by electrospinning. A PVA/MWNTs solution was electrostatically spun to form filler wrapped nanofibers, with a diameter of ∼ 100-200 nm. As the concentration of filler in the composite was varied, the coloration of the fiber sheets changed. The SEM and TEM analyses of the fiber sheets revealed that the deformation of the fiber increases with increasing nanotube concentration. The mechanical properties were studied using a universal testing machine (UTM). The analysis is presented in detail. It is argued that the degree of dispersivity orientation and anisotropy of the nanotubes and the amount of interfacial stress in the filler/polymer are the predominant factors determining the variation in the tensile properties of the composites with the filler concentration.     

Ordered carbon nanotubes for optical power limiting devices

The electrospinning (ES) process was used to fabricate composite nanofibers (NFs) of poly(methyl methacrylate), PMMA, with embedded multiwalled carbon nanotubes (MWNTs) from a solution of PMMA in N,N-dimethylformamide (DMF) with homogenously dispersed MWNTs. Using both the sinklike and the elongation flows in the electrospinning process, we aligned the carbon nanotubes (CNTs) along the fiber axis. The NFs were subsequently deposited in an aligned manner on a glass surface using the electrostatic lens created by the edge of a rotating wheel collector. Semitransparent optical power limiter (OPL) films (~50% transmittance) were fabricated using an optically compatible polymeric resin infiltrated into the collected NFs. These comprised oriented NFs with different carbon nanotube loadings and film thicknesses. The OPLs exhibited high limiting abilities, with a limiting threshold of 1.5 J/cm(2) at about 50% linear transmittance. Some degree of polarization was also achieved, but significantly lower than expected because of the NF orientation.     

左旋聚乳酸/多壁碳纳米管/羟基磷灰石电纺丝纳米纤维的形态及生物降解性能

采用静电纺丝法制备了左旋聚乳酸/多壁碳纳米管/羟基磷灰石(PLLA/MW NT s/HA)杂化纳米纤维无纺毡,分析了MW NT s的加入对杂化纤维形态结构的影响,以及不同工艺条件下纤维的直径分布,并研究了纤维无纺毡在磷酸盐缓冲溶液(pH 7.4,37℃)中的体外降解过程。结果表明:MW NT s的加入使PLLA/HA纤维直径略有减小;PLLA/MW NT s/HA杂化纤维体系降解液的pH值下降到一定程度后,在降解后期呈缓慢上升趋势;碱性MW NT s/HA的加入抑制了PLLA降解过程中的自催化作用,减缓了PLLA的降解速度。     

Characterization and mechanical performance comparison of multiwalled carbon nanotube/polyurethane composites fabricated by electrospinning and solution casting

Multiwalled carbon nanotube/polyurethane (MWNT/PU) composites were prepared by electrospinning and solution casting. The morphological and thermal properties, and mechanical performance of the nanofiber and film composites were characterized and compared. The tensile strength of neat PU film was 9-fold higher than that of neat PU nanofibrous mat. The incorporation of MWNTs increased the tensile strength and modulus of the composite nanofibers by 69% and 140%, respectively, and 62% and 78%, respectively for composite films. The MWNT/PU composites showed an improved thermal degradation behavior, with the incorporation of low MWNT content in the composites.     

Effect of pyrene-modified multiwalled carbon nanotubes on the properties of epoxy composites

The block polymer of poly(styrene-b-pyrene) (PS-b-PAH) containing pyrene units was successfully applied on the surface of multiwalled carbon nanotubes (MWNTs) and the properties of nanocomposites were enhanced. The morphology of the modified MWNTs was characterized by transmission electron microscopy (TEM), and the results showed that PS-b-PAH helped effectively the MWNTs to disperse well in epoxy matrices, and these dispersed MWNTs were stabilized by the pyrene modifier. The mechanical properties of the composites, such as impact toughness and flexural strength, and the electrical conductivity of the nanocomposites, are improved significantly after the treatment of the MWNTs using PS-b-PAH. The results show that the mechanical and electrical properties of the modified MWNTs/epoxy composites with PS-b-PAH are obviously superior to those of pristine MWNTs/epoxy composites. The enhanced interfacial interactions lead to good dispersion of MWNTs in epoxy matrices, thus enhancing the mechanical and electrical properties of the nanocomposites.