表面活性剂对碳纳米管分散性及其湿法纺丝纤维性能的影响

碳纳米管(CNT)纤维因具有低密度、高强度以及高电导率等特性受到广泛关注。在湿法纺丝技术制备CNT纤维的工艺中,探究纺丝分散液和纺丝条件对CNT纤维性能的影响具有重要意义。本文研究了十二烷基硫酸钠(SDS)、十六烷基三甲基溴化铵(CTAB)、胆酸钠(SC)、牛磺脱氧胆酸钠(STDC)等表面活性剂对CNT纤维制备及性能的影响。通过拉曼光谱、紫外可见光谱、偏光显微镜、旋转流变仪、扫描电镜等方法对材料进行表征,以拉伸测试和“四探针”法对材料性能进行测试。结果表明,单壁碳纳米管(SWNTs)在表面活性剂的2(wt)%水溶液中的分散能力顺序依次为STDC> SC> CTAB> SDS;SDS或CTAB修饰的SWNTs分散液无法纺制纤维,SC和STDC修饰的SWNTs分散液具有良好的可纺性。其中以STDC作表面活性剂制备的CNT纤维性能最好,其断裂强度为160MPa,杨氏模量为12.3GPa,电导率为2300S/cm。

Effects of Surfactants on the Dispersibility of Carbon Nanotube and Properties of Wet-spun Fibers

Carbon nanotube (CNT) fibers have attracted much attention due to their low density, high strength and high electrical conductivity. SIt is of great significance to investigate the effects of spinning dispersion and spinning conditions on the properties of carbon nanotube fibers in preparation of carbon nanotube fibers by wet spinning technology. The effects of surfactants such as sodium dodecyl sulfate (SDS), cetyl trimethyl ammonium bromide (CTAB), sodium cholate (SC) and sodium taurine deoxycholate (STDC) on the preparation and properties of carbon nanotube fibers were investigated.SThe materials were characterized by UV-VIS, PLM, Rheometer, SEM, tensile test and "four-probe" method. SThe results showed that when the mass fraction of surfactant was 2%, the order of dispersion ability of single-walled carbon nanotubes in water was STDC>SC>CTAB>SDS.SSDS or CTAB as surfactant dispersion of single-walled carbon nanotubes can not produce fibers. SC and STDC as surfactant have good spinnability. The fiber prepared by using STDC as surfactant has the best properties, with breaking strength of 160 MPa, Young"s modulus of 2.3 GPa and conductivity of 2300 S/cm.