Aqueous Dispersion of Carbon Nanotubes by Simple Aromatic Molecules: Effects of Aromatic Ring Numbers and Substituted Groups

Abstract

Aqueous dispersion of SWNTs was achieved by using simple aromatic molecules as dispersants. Aromatic molecules used in this study were naphthalene, anthracene, and pyrene with or without a carboxyl group. Absorption spectra of SWNTs wrapped with the aromatic molecules exhibited that both the greater number of aromatic rings and the presence of carboxyl groups were required for the dispersion of SWNTs. It was therefore suggested that both π-π interactions between SWNTs and the aromatic molecules, and the hydrophilicity of the aromatic molecules were significant for the dispersion of SWNTs. AFM observations demonstrated that the disentangled SWNTs were prepared from bundled SWNTs by wrapping with the aromatic molecules. Our results will be utilized as basic data for dispersion and disentanglement of SWNTs in water.