Effect of organic counter-ion on the surface activity, micellar formation and solubilizing behaviour of a cationic surfactant

Abstract

The effect of 18 organic anions (aliphatic and aromatic, both mono-and dicarboxylates) on the surface and micellar behaviour of cetyltrimethyl- ammomium bromide (CTAB) in aqueous solution has been examined by surface tension and dye-solubilization measurements. The effects of these counter-ions as observed from surface activity, critical micelle concentration and dye solubiling efficiency is examined in terms of their condensation/penetration onto/into the micelles Ions which show condensation onto the micelle surface or are capable of being easily incorporated into the micelles show greater surface activity, lower CMC and higher dye solubilisation efficiency of CTAB.