Adsorption of nonpolar benzene derivatives on single-walled carbon nanotubes

The adsorption of benzene, toluene, and chlorobenzene on single-walled carbon nanotubes (SWCNTs) with and without acid oxidation was conducted to investigate the influences of derivative groups on benzene rings and functional groups from SWCNTs on adsorption by SWCNTs. The SWCNTs of high purity were chosen and moderate acid oxidation was performed so that the surface physical properties remained unchanged after acid oxidation and the influences of acid oxidation on adsorption were only contributed from the modification of the surface chemistry of SWCNTs. The oxygen-containing surface groups introduced by acid oxidation obstructed the interactions between functional groups of nonpolar benzene derivatives and C-rings of SWCNTs significantly. The dispersive interaction between the partially positive H+ of the methyl group and the oxygen-containing surface groups slightly increased the adsorption of toluene on oxidized SWCNTs at high solution pH. The thermodynamic of adsorption was also studied at different temperatures.