246 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS hair (9). The equivalence of the surface polymer content as measured by ESCA indicates that this increased substantivity is most likely due to polymer absorption into the damaged hair fibers. SUMMARY AND CONCLUSIONS ESCA has proven to be useful for studies of polymer deposition and substantivity on hair fiber surfaces. Owing to the extreme surface selectivity of the ESCA technique, an indication of polymer surface coverage can be obtained that is not readily available by bulk analytical techniques. Both the cellulosic conditioning polymers tested exhibit relatively high levels of ad- sorption. However, retention of Polyquaternium-10 appears to be significantly in- fluenced by changes in the character of the hair surface along the length of the fiber, showing increased adsorption at the tip end of the hair fiber. In contrast, Polyquater- nium-24 shows higher overall levels of polymer deposition and does not exhibit this preferential adsorption. Post-treatment with SDS of hair samples exposed to Polyquaternium-10 and Polyqua- ternium-24 was shown to reduce the surface concentration of polymer on the hair. Deposition of three non-cellulosic cationic conditioning polymers has also been exam- ined. Of these, Polyquaternium-! 1 shows the highest substantivity. While this paper has emphasized analysis of adsorbed polymers, the ESCA technique is obviously well suited to the determination of other species, such as adsorbed surfactants and UV absorbers. ACKNOWLEDGEMENTS The data presented in this report were made possible by the skillful work of D. H. Scofield (ESCA) and E. Lesniak (hair treatments). T. Kinisky is also gratefully acknowl- edged for his contributions in performing the initial ESCA measurements. REFERENCES (1) E. D. Goddard, Substantivity through cationic substitution, Cosmetics and Toiletries, 102, 71-80 (1987). (2) D. T. Clark, "The Investigation of Polymer Surfaces by Means of ESCA," in Polymer Surfaces, Clark and Feast, Eds. (John Wiley & Sons, New York, 1978), pp. 309-353. (3) C. R. Robbins and M. K. Bahl, Analysis of hair by electron spectroscopy for chemical analysis,.]. Soc. Cosmet. Chem., 35, 379-390 (1984). (4) L. Zhao, S. Liu, and T. Wang, A study of the mechanism of the oxidation of hair keratin by photoelectron spectroscopy, Acta Biochimica et Biophysica Sinica, 13, 503- 507 (1981). (5) A. Dilks, Polymer surfaces, Anal. Chem., 53, 802A-816A, (1981). (6) Y. K. Kamath, C. J. Dansizer, and H.-D. Weigmann, Surface wettability of human hair. I. Effects of deposition of polymers and surfactants, J. Appl. Poly. Sci., 29, 1011-1026 (1984). (7) H.-D. Weigmann and Y. K. Kamath, Modification of human hair through fiber surface treatments: Characterization by wettability, Cosmetics and Toiletries, 101, 37-49 (1986). (8) J. A. Faucher and E. D. Goddard, Influence of surfactants on the sorption of a cationic polymer by keratinous substrates, J. Colloid Interface Sci., 55, 313-319, 1976. (9) E. D. Goddard, J. A. Faucher, R. J. Scott, and M. E. Turney, Adsorption of Polymer JR on kera- tinous surfaces,.]. Soc. Cosmet. Chem., 26, 539-550 (1975).

J. Soc. Cosmet. Chem., 38, 247-262 (July/August 1987) A quantitative diffuse reflectance method using Fourier transform infrared spectroscopy for determining siloxane deposition on keratin surfaces HELEN M. KLIMISCH and GRETCHEN S. KOHL, Dow Corning Corporation, 2200 West Salzburg Road, Midland, MI 48640 and JOAN M. SABOURIN, Delta College, University Center, Auburn, MI 48710. Received December 1 O, 1986. Synopsis Methodology was developed for the detection and quantitation of siloxanes on keratin fibers using DRIFTS. Sample preparation procedures were defined and optimized for surface and bulk analysis of the fiber. The effort has demonstrated that DRIFTS band ratio data can be correlated to mg/kg Si data generated independently by atomic absorption analysis of hair fibers. A linear relationship was observed over the 250 to 1840 mg/kg Si range of this study. The deposition of any material that has a distinctive IR band could also be assayed by this method. The success of the method is almost totally dependent upon sample preparation and generation of a KBr-reflective surface to produce the surface analysis. INTRODUCTION Keratin fibers, such as human hair, undergo environmental damage due to UV radia- tion and atmospheric oxidation, mechanical damage by grooming devices, and chemical damage from permanent waving lotions, bleaches, dyes, and even shampoos. So-called conditioning agents can be used on the hair, usually after shampooing, to produce improvements in fiber properties by depositing ingredients on the fiber surface. Some typical organic conditioning agents are organic quaternary ammonium compounds and long-chain animal proteins. Previous studies (1-3) have shown that polysiloxanes, especially organofunctional polysiloxanes, also act as conditioning agents. Silicone de- position on hair fibers has been investigated using electron microscopy, atomic absorp- tion (AA), and electron spectroscopy for chemical analysis (ESCA). Scanning electron microscopy (SEM) provides a qualitative means for detecting the presence of a film on the fiber surface. ESCA is a surface analysis technique ø capable of determining the con- centration of elemental silicon within the top 50A of the fiber. An AA method was developed (4) for quantitatively measuring the silicon content of the whole fiber. The general conclusion based on these methods is that combing ease or conditioning improved as the silicon content of the fiber increased. AA provides information on 247