134 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS (41) (42) (43) (44) (45) (46) (47) (48) (49) (50) Barnett, op. cit., p. 86. Neergaard, P., Danish Species of Alternaria and Stemphylium, Hmnphrey Millford. Oxford University Press, London, 1945. Luttrell, E. S., A key to species of Helminthosporium reported on grasses in the United States, Plant Disease Reptr., Suppl. No. 201, 59 (May 15, 1951). Idson, B., Dandruff: Cause and control, Drug Cosmetic Ind., 96, 636 (1965). Lesser, M. A., Dandruff, Ibid., 70, 320 (1952). Levine, O. L., Your Hair and Your Health, Greenberg Co., New York, 1926, p. 44. Templeton, H. J., A study of dandruff and of the Pityrosporon of Malassez, Arch. Dermatol. and Syphilol., 14, 270 (1926). Mitsutsugu, O., and Abe-Tsutomu, Studies on the depilitation of scalp hair and scurf. 1st Rept.: Seasonal variation, J. Physiol. Soc. Japan, 24, 252 (1962). Spoor, H. J., Microbiological and clinical study of antidandruff agents, Proc. Sci. Sect. Toilet Goods Assoc., 23, 27 (May 1955). Spoor, H. J., Clinical evaluation of antidandruff formulations, J. Soc. Cosmetic Chemists, 14, 135 (1963).

J. Soc. Cosmetic Chemists, 20, 135-152 (Feb. 5, 1969) Sorption of Ouaternary Ammonium Surfactants by Human Hair GEORGE V. SCOTT, Ph.D., CLARENCE R. ROBBINS, Ph.D., and JAMES D. BARNHURST, Ph.D.* Presented December 6, 1967, New York City Synopsis--The sorption of cationic surfactants (cationics) from aqueous solution onto hair is determined as a function of time using a solution depletion method. The solutions are periodically analyzed for cationic content by an Orange II dye procedure. Data from the sorption runs are conveniently processed by a programmed computer. Two quaternary amxnonium surfaetants, hexadeeyl-(CTAB) and dodeeyl-(DTAB) tri- methylammonium bromides, have been studied under various experimental conditions. The rate of CTAB sorption onto hair increases with increased pH or temperature, choice of buffer anion, or use of bleached hair. A decrease in "hair-to-solution" ratio also causes an increase in CTAB sorption. The rate of sorption decreases when lower solution concentra- tions are used or the eationic chain length is shortened (DTAB) Desorption of CTAB and DTAB is demonstrated by dilution of the partially depleted solutions in contact with hair. INTRODUCTION The action of quaternary ammonium surfactants is often dramatic on hair that has been damaged by treatments such as bleaching or cold waving. As creme rinses following a shampoo, they improve the hair with respect to feel or "hand," combing ease, snarl removal, and they de- crease electrical charges during brushing or combing. Quantitative tests are available in the literature which show that creme rinses reduce fric- tion (1), electrical charge buildup (2-4), and raspiness (5) of human hair. Attempted explanations of these actions invariably lead to considera- tion of the relative sorptive tendencies of these surfactants. Direct * Colgate-Palmolive Research Center, Piscataway, N. J. 08854. 135