Dispersion of multi-walled carbon nanotubes (MWCNTs) by ionic liquid-based phosphonium surfactants in aqueous solution

► Alkyl-triphenyl phosphonium bromide surfactants can disperse MWCNTs in water. ► The TEM micrograph shows the well isolated state of MWCNTs with the aid of C14TPB. ► The π-π stacking interaction and hydrophobic interaction make CnTPB molecules adsorb on the surface of MWCNTs.