Adsorption of Cationic-Anionic Surfactants to Keratin Powder

Abstract

The adsorption of a cationic-anionic surfactants mixed system on keratin powder was studied using keratin powder in place of hair. The anionic adsorption isotherm of anionic surfactant was of the Langmuir-type. Those of cationic surfactant and cationic-anionic surfactant mixed system showed irreversible adsorption owing to strong interaction with keratin powder. The extent of adsorption was maximum at molar ratio 7/3 of cationic/anionic surfactants. The kinetic frictional coefficient was least and interaction between surfactants and ovalbumin, weakest. That the cationic-anionic surfactants mixed system has the properties of nonionic surfactant in aqueous solution and that the monomer concentrations of cationics having strong irritation decrease may suffice as explanation for the above results.