Silicones have been widely used in hair care products as an effective component to impart smooth feeling, ease in combing, and gloss to hair. In this work, the sorption behavior of silicone on hair in the aqueous solutions is discussed in terms of the hair surface condition by measuring the wetting force of hair fibers in relation to the hair surface damage. The amount of silicone adsorbed on hair surface was higher at the hydrophobic root part and less at tip part or damaged hair by chemical treatments (perming and bleaching), which became more hydrophilic.
This result implies that (1) the hydrophobic interaction between dimethylsiloxane units and hair surface, and (2) the hydrophilic interaction between water and hair surface play an important role in the sorption behavior of silicone on hair. We found that the amount of silicone adsorbed on the damaged hair treated with a cationic surfactant increased with increasing cationic surfactant sorption, and this can introduce a control technique in the sorption behavior of silicone on the damaged hair.
