MnO2/C复合纳米纤维纱线的制备及其导电性能

采用共轭静电纺丝法制备聚丙烯腈(PAN)纳米纤维纱线,并在不同温度下将PAN纳米纤维碳化得到碳纳米纤维纱线。以KMnO 4为锰源,通过水热合成法在碳纳米纤维纱线上原位生长纳米二氧化锰(MnO 2),形成MnO 2/C复合纳米纤维纱线,分别采用傅里叶变换红外光谱(FTIR)、扫描电子显微镜(SEM)、场发射扫描电子显微镜(FE-SEM)、数字万用表对碳纳米纤维纱线和MnO 2/C复合纳米纤维纱线的化学组成、表观形貌、电学性能等进行表征,并分析碳化温度对碳纳米纤维纱线的形貌和电学性能的影响,以及水热反应中盐酸浓度对纳米MnO 2形貌和MnO 2/C复合纳米纤维纱线的影响。结果表明:碳化温度越高,得到的纱线表面越光洁,石墨化程度越高,电学性能也越好,1000℃碳化工艺得到的碳纳米纤维纱线电导率最高,为31.5 S/cm;与MnO 2复合后的碳纳米纤维纱线电导率大幅下降,当盐酸与高锰酸钾摩尔浓度比为4∶1时得到的复合纳米纤维纱线的电导率最高,为0.1200 S/cm。

Preparation and Conductive Properties of MnO 2/C Composite Nanofiber Yarn

Polyacrylonitrile(PAN)nanofiber yarns were prepared by conjugate electrospinning,and carbon nanofiber yarn(CNY)were obtained by carbonizing PAN nanofibers at different temperatures.Nano-manganese dioxide(MnO 2)was grown in-situ on CNY by hydrothermal synthesis using KMnO 4 as a manganese source to form MnO 2/C composite nanofiber yarns.Fourier transform infrared spectroscopy(FTIR),scanning electron microscopy(SEM),field emission scanning electron microscopy(FE-SEM),and digital multimeter were used to characterize the chemical composition,apparent morphology,and electrical properties of CNY and MnO 2/C composite nanofiber yarns respectively.The effect of temperature on the morphology and electrical properties of CNY and MnO 2/C composite nanofiber yarns was analyzed,and the effect of hydrochloric acid concentration on the morphology of nanometer MnO 2 in hydrothermal reaction was also analyzed.The results show that higher carbonization temperature leads to smoother surface,higher degree of graphitization and better electrical properties of the obtained yarn.The highest conductivity of carbon nanofiber yarn obtained by the carbonization process at 1000℃is 31.5 S/cm.The electrical conductivity decreases significantly after compounding with MnO 2.When the molar concentration ratio of hydrochloric acid to potassium permanganate is 4∶1,the electrical conductivity of the composite yarn is the highest among the composite yarns,which is 0.1200 S/cm.