Performance improvement of continuous carbon nanotube fibers by acid treatment

Zhang Qiang^{1, 3}, Li Kewei¹, Fan Qingxia^{1, 3}, Xia Xiaogang^{1, 3}, Zhang Nan¹, Xiao Zhuojian^{1, 3}, Zhou Wenbin¹, Yang Feng^{1, 3}, Wang Yanchun^{1, 2, 3}, Liu Huaping^{1, 2, 3}, Zhou Weiya^{1, 2, 3, †}

(color online) SEM images of morphologies of twisted CNT fibers without (panels a, c, and e) and with (panels b, d, and f) chlorosulfonic acid treatment. Panels (a) and (b) are the twisted CNT fibers. The diameter is reduced distinctly after the acid treatment. (c) and (d) The fracture morphology of the fibers in panels (a) and (b), respectively. The sliding distance is decreased significantly after acid treatment. (e) and (f) The surface of the fibers in panels (a) and (b), respectively. The CNTs in the fibers are dense after the acid treatment.