342 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS A photometer-microscope with a computer-con- trolled fast scanning table is described. With a spe- cial software program, cross-sections of dyed human hair can be analyzed automatically with respect to dye distribution from the outside to the inside of the hair shaft. Very important for such a measure- ment is the producing of microtome cross-sections of defined thickness in a reproducible manner. With some direct dyestuffs the influence of dyeing time on the dye-distribution profile across the hair section is demonstrated. The advantage of carrying out these measurements at a specific wave length at which the dyestuff has its maximum absorption, is shown. SCIENTIFIC SESSION IV HAIR TREATMENTS, PART II Relative detergency evaluation of shampoo for- mulations Donald Thompson, Carole LeMaster, Rebecca Allen, Milton Palmer, and James Whittam, Shaklee Corporation, Research & Development, 1992 Al- pine Way, Hayward, CA 94545 When developing new shampoos, formulators need an easy way by which to assess the relative deter- gency of the prototype to a control shampoo. To address this problem, we have developed a rapid and precise procedure for hair-swatch soiling and treatment. Sebum residues are determined after treatment using gas chromatography and computer- aided data reduction. The new treatment technique was found to be significantly more precise than the "traditional" finger-squeeze procedure. This pro- cedure was used to evaluate several shampoo for- mulations and to investigate component removal and total sebum residue after treatment. Differences in relative detergency were evaluated at two sebum soiling levels using a nine-component sebum in hexane solution. After shampoo treat- ment, the analysis of the residual sebum present indicated that some sebum components were re- moved less extensively than others. This observation led to the investigation of the possible concentration of various sebum components with repeated soiling and washing with the same shampoo formulation. The development and validation of the technique will be described along with plans for future inves- tigations. Foam stability fundamentals James A. Wingrave, E. I. dupont de Nemours & Co., 1213 Jackson Laboratory, Deep Water, NJ 08023 Since foam is an unstaNe state of nature, control over its decay rate is the goal of foam stability studies. Hence, the desired control in any foam sta- bility investigation is to either increase or decrease the decay rate. These respective processes are re- ferred to as foam stabilization or foam breaking. In this presentation the physical and chemical fac- tors responsible for stabilizing foam will be exam- ined in both the absence and presence of a foamicide or soil. In the former case, where no soil is present, the relationship of bubble geometry, viscosity, sur- factant diffusion, and vapor and air diffusion to foam and bubble stability will be investigated. Tests to measure these elements of foam stability will be presented. When soil is present, the rate-limiting step in foam stability becomes dependent upon the interaction of the foam and soil. The mechanism by which soil destabilizes foam will be delineated, and some test methods suitable for studying these mechanisms will be examined. Lather--its importance to the consumer and to the formulating chemist J. Roger Hart, Organic Chemicals Division, W. R. Grace & Co., 55 Hayden Ave., Lexington, MA 02173 The ability of shampoos to form a creamy, rich lather, while commonly recognized as being im- portant to the consumer, has often been considered to be of little or no technical importance by the cosmetic chemist. A new look at the foaming and lathering properties of shampoos, with particular emphasis on the cru- cial differences between lather and foam, adds a new dimension to the selection of ingredients and the formulation of successful products. The ability of the lather to aid in distributing the product through the hair, increasing the viscosity to hold the diluted shampoo in place, assists in the suspending of soil, and as an indicator of the completeness of rinsing is an important technical benefit. The achievement of good lather properties has, however, been confused by the use of dilute foam test methods as a measure of the lathering ability of the product. Newer methods have been patterned on more realistic conditions and these test results are shown to compare quite favorably with actual salon evaluations. Examples of misleading results from the traditional dilute test methods and their potential for misinterpretation will be demon- strated. The principal environmental and formulation fac- tors which influence lather volume and quality will also be discussed in light of these new techniques.

ABSTRACTS 343 Electron microscopy--image analysis: quantifi- cation of ultrastructural changes in hair as a result of cosmetic treatments Raymond L. Sneath, Ph.D. and Jacalyn G. Gould, The Gillette Co., Gillette Park, Boston, MA 02106 In a recent publication, Zahn et al. described the dissolution of ultrastructural components in hair fi- bers as a direct result of various cosmetic treat- ments. These observations were based on a subjec- tive assessment of holes or voids observed in electron micrographs of hair fiber cross-sections. We have further investigated these effects using electron mi- croscopy in conjunction with image analysis. Cross- sections of proximal and distal ends of intact hair fibers were examined before and after repeated shampooings. The total number of holes, total pro- jected areas, mean areas, and size distributions were determined in the cuticle and cortex regions of hair fibers using a Quantimet 900 Image Analyzer. All measured parameters indicated that ultrastructural disruption increased from the proximal to the distal end of hair fibers. The impact of shampooing on the fiber ultrastructure appeared to be small. The utility and applicability of the technique for hair damage evaluation will be discussed. Aminofunctional silicones: a new class of poly- mers for hair care Gretchen S. Kohl, Michael S. Starch, and Grish Chandra, Ph.D., Dow Corning, 2200 W. Salzburg, Midland, MI 48640 Dimethicones (dimethyl silicone polymers) have long been a useful component of cosmetic and hair care formulations. The use of these polymers in hair care, however, has been somewhat limited due to the difficulty in providing controlled deposition onto the hair. Trimethylsilylamodimethicone, a new class of silicone polymers containing amino- functional groups, has been shown to be far superior to other silicones in providing conditioning benefits on hair due to their affinity for the hair surface. The deposition properties and the effects of the deposited film have been studied using a variety of instru- mental techniques. These include Instron Combing and Atomic Absorption analysis of treated hair sam- ples. Data will be presented to illustrate the be- havior of aminofunctional silicones relative to other materials with respect to deposition from dilute aqueous systems, combing force reduction, and du- rability of the deposited material.