INTERACTIONS OF CATIONIC AND ANIONIC SURFACTANTS ON HAIR SURFACES - LIGHT-SCATTERING AND RADIOTRACER STUDIES

Light-scattering techniques, supplemented by radiotracer studies, have been used in this work to demonstrate formation on hair surfaces of i nsoluble complexes between some common cationic conditioner actives an d anionic lauryl and laureth sulfates. These complexes, which were fou nd to be very dulling and resistant to cleaning by C12-based detergent s, were shown to form in tress treatments and also in treatments of fu ll heads of hair. Alkyl ether sulfates having hydrophobic chain length s of 6, 8, or 10 were found not to form the above types of complexes o n hair and were shown to be superior for use in cleaning conditioners. In experiments with conditioner actives, contributions to buildup wer e found from both conditioner and detergent deposition. In the case of commercial conditioners, buildup was observed only as a result of exc ess detergent deposition in the presence of conditioner. In both cases , formation of insoluble complexes led to greatly reduced cleaning by lauryl or laureth sulfate-based shampoos.