H_2O_2活化聚酰亚胺碳纳米纤维无纺布及其储电性能

聚酰亚胺碳纳米纤维无纺布经双氧水在氮气氛中750℃活化,使其比表面积增大,从而改善其储电性能.通过透射电镜观察活性碳纳米纤维的尺寸、形貌和结构;采用次甲基蓝水溶液吸附法测定活化碳纳米纤维的比表面积;用CHI660B电化学工作站测定该活性碳纳米纤维电极的储电性能.结果显示:活化后碳纳米纤维具有更大的比表面积,表面粗糙,电极材料的储电性能随活化程度的提高而增大;聚酰亚胺碳纳米纤维电极具有良好的超级电容器特性,在1 mol/L的H2SO4电解液中,经6 h活化后的碳纳米纤维电极具有良好的电荷储存能力,比电容量达到174.2 F/g.

聚苯胺/碳纳米纤维复合材料的制备及电容性能

采用原位聚合法制备了聚苯胺/碳纳米纤维(PANI/CNF)复合材料,用傅里叶变换红外(FT-IR)光谱、热重分析(TGA)、扫描电镜(SEM)和孔分布及比表面积测定仪研究了复合材料的表面官能团、组成、表面形貌及比表面积,并运用循环伏安(CV)法和计时电位法测试了PANI/CNF布作为电极材料的电化学性能.研究结果表明:PANI/CNF复合材料具有粗糙的毛刺结构,PANI沿碳纳米纤维均匀分布;PANI/CNF电极氧化还原反应的可逆性良好;在100mA·g-1电流密度下,当PANI含量为44.4%(w)时,复合材料比电容量高达587.1F·g-1,比能量为66.1Wh·kg-1,电流密度为800mA·g-1时比功率可达1014.2W·kg-1;在5A·g-1的电流密度下,1000次循环充放电后,复合材料的比电容量衰减28%.PANI/CNF复合材料具有良好的导电性和快速充放电能力,是一种优良的超级电容器电极材料.

In-situ thermal Raman mapping and stress analysis of CNT/CF/epoxy interfaces

A study of the interfacial behavior and internal thermal stress distribution in fiber-reinforced composites is essential to assess their performance and reliability.CNT/carbon fiber(CF)hybrid fibers were constructed using electrophoretic deposition.The interfacial properties of CF/epoxy and CNT/CF/epoxy composites were statistically investigated and compared using in-situ thermal Raman mapping by dispersing CNTs as a Raman sensing medium(CNT_(R))in a resin.The associated local thermal stress changes can be simulated by capturing the G'band position distribution of CNT_(R) in the epoxy at different temperatures.It was found that the G'band shifted to lower positions with increasing temperature,reaching a maximum difference of 2.43 cm^(−1) at 100℃.The interfacial bonding between CNT/CF and the matrix and the stress distribution and changes during heat treatment(20-100℃)were investig-ated in detail.This work is important for studying thermal stress in fiber-reinforced composites by in-situ thermal Raman mapping technology.