Dye adsorption-assisted colloidal dispersion of single-walled carbon nanotubes in polar solvents

Abstract

Micellar surfactants with amphiphilic chemical structures are mostly used to disperse single-walled carbon nanotubes (SWCNTs) in water. However, there is little systematic knowledge regarding the use of low-molecular-weight nonmicellar adsorbates as efficient surfactants for colloidal SWCNT dispersions, which limits the number of available solvents. In this article, we present an empirical rule for adsorbate-based dispersants required for SWCNT dispersion in polar organic solvents and water. First, we demonstrate that SWCNTs can be dispersed in aqueous media with the aid of the non-aqueous stilbene backbone compound amsonic acid. The impact of nonmicellar physical adsorption on dispersion was systematically examined using low-molecular-weight compounds, including Fluorescent Brighteners 28 and 220. This discovery has increased the availability of solvents such as water, polar organic solvents such as alcohols, and surfactants such as widely used organic dyes. The results of our study indicate that effective nonmicellar dispersants should include acid–base-carrying structures. The present findings have elucidated the colloidal chemistry of nanocarbon materials with significant potential for application as low-molecular-weight adsorbate-enhanced multifunctional inks.