Liquid-Crystal Phase Reinforced Carbon Nanotube Fibers

Fibers are promising forms to use carbon nanotubes (CNTs) on the macroscopic scale. Physical and chemical properties of carbon nanotubes, dispersants, and the phase behavior of carbon nanotube suspensions have great impact on the performance of the fibers. In this paper, single-walled carbon nanotube fibers were made by rotating PVA (poly(vinyl alcohol))-based coagulation spinning. Scanning electron microscopy was used to observe the surface and cross section of the fibers. The orientation degree of the fibers was analyzed by polarized Raman spectra. The influence of single-walled carbon nanotube (SWCNT) source materials and different dispersants on the performance of the fibers was investigated systematically for the first time. The results show that purification and acid oxidation of SWCNTs can enhance the fiber strength. Compared to SDS (sodium dodecyl sulfate) and SDBS (sodium dodecyl benzene sulfate), SLS (sodium lignosulfonate) is the best dispersant to fabricate carbon nanotube fibers with a higher strength. The performance of the fiber was improved greatly due to the information of the liquid-crystal phase, and fibers with the strength of 520 MPa were fabricated.