Increased Solubility, Liquid-Crystalline Phase, and Selective Functionalization of Single-Walled Carbon Nanotube Polyelectrolyte Dispersions

Abstract

The solubility of single-walled carbon nanotube (SWCNT) polyelectrolytes [K(THF)]_<i>n</i>SWCNT in dimethyl sulfoxide (DMSO) was determined by a combination of centrifugation, UV–vis spectral properties, and solution extraction. The SWCNT formed a liquid crystal at a concentration above 3.8 mg/mL. Also, crown ether 18-crown-6 was found to increase the solubility of the SWCNT polyelectrolytes in DMSO. Raman spectroscopy and near-infrared (NIR) fluorescence analyses were applied to study the functionalization of SWCNTs. Small-diameter SWCNTs were found to be preferentially functionalized when the SWCNT polyelectrolytes were dispersed in DMSO