Ingredient Citric acid Stearamidopropyl dimethylamine Cetyl alcohol Stearyl alcohol Glyceryl stearate Stearth-20 Dimethicone HAIR SURFACE CHEMISTRY Table I Test Conditioning Formulation Diester quaternary amine (Armocare VGH-70) Water 67 Active weight (%) 0.2 0.8 1.9 0.8 0.7 0.3 0.9 2.75 Balance with a 3% hydrogen peroxide solution, sodium bisulfite activator, and 0.25% sodium lauryl sulfate, at pH = 9. A 10% conditioning dispersion was prepared as noted above and the hair swatches were exposed for 60 seconds and then rinse for 30 second at 39°C. XPS XPS spectra were collected at room temperature with a Physical Electronics 5600ci electron spectrometer. Excitation of the sample was accomplished with a monochromatic Al k x x-ray source (hv = 1486.7 eV, 250 w) producing an approximately 7 x 3 mm illuminated area on the sample. Photoelectrons from a 0.8 x 0.8 mm area were energy analyzed with a 279 mm mean diameter hemispherical electron energy analyzer. The angle above the surface plane to the electron collection lens axis was 4 5 ° . Surface charge neutralization was performed with an electron flood gun source, nominally operated at 18 ma emission and 0. 5 V acceleration potential. Exact flood gun conditions were optimized for each sample to obtain minimum peak width with the hydrocarbon C(ls) binding energy around 284.4-284.0 eV. Duplicate analyses were run from the hair fiber samples for collection of elemental survey and high resolution chemical state data. Differing areas of the mounted hair fibers were selected using the internal optical microscope to obtain results from separate areas on the fibers. Low resolution, "survey scan" and high resolution chemical state spectra were collected in fixed analyzer transmission mode at pass energies of 187 .85 eV and 23.50 eV re­ spectively. Spectrometer resolution, measured as full width at half maximum of the 3d5/2 photo electron peak from Ag foil were, 2.4 eV (187.85 eV pass energy) and 0.8 eV (23.5 3 V pass energy). Binding energy scale calibration was performed as described in the E-42 ASTM-902 document. The procedure employs the peak separation of the Cu(2p3/2) and Cu (3p3/2) photoelectron peaks to first establish scale linearity. The Cu photopeaks and the Cu (KLL) Auger peak positions are then used to calibrate the absolute energy scale. Binding energy assignments for the charge compensated (shifted) sample spectra were based on an assignment of the hydrocarbon (-CH2-) C(ls) component in the high resolution C(ls) spectrum being at 284.8 eV. Samples for every analysis were taken from as near the mid-point along the length of the hair tress as could be reproducibly achieved. Hair fibers were mounted between two,

68 JOURNAL OF COSMETIC SCIENCE three hole, sample cover masks, (Physical Electronics part # 612448) to hold the fibers co-planar and parallel. Double sided tape was placed on either side of the holes on the lower mask, the fibers (-20) cut to about 2" in length were placed and pressed onto the tape across the hole. The second mask was placed above the first, screws were run through both masks into the recessed sample mount (Physical Electronics part 606142) securing the fibers in place. The sample mount was placed within the spectrometer so that the hair fibers were oriented parallel to the source-analyzer plane. Instrument control, data collection and data analysis were performed with RBD Au­ gerscan V3 running on a Pentium PC. Quantization calculations were based on mea­ sured peak areas and empirical instrumental sensitivity factors. Curve fitting analysis employed a linear background and mixed Gaussian-Lorentzian peak shape. SEM Electron microscope images were collected with a Zeiss EVO-50 XVP instrument. This instrument is capable of operation from high vacuum to 700 Pa at the full range of electron beam voltages. Images for this work were collected with a secondary electron detector. Probe beam energy was 15 KV. A thin coating of Au was evaporated onto the surface of the fibers to minimize charge buildup. Magnifications of 1 Kx and 2.5 Kx are shown of the hair fibers at the various treatment stages of this study. RESULTS BLANK HAIR The natural hair surface is composed of C, 0, N, S, Si and Ca. A representative survey scan is shown in Figure 1. Note that in Figure 1, the 2s (-230 eV) and 2p (-185 eV) photoelectron transitions from S are observed as doublets. Each of these S photoelectron transitions is comprised of two unresolved peaks due to disulfide (-S-S-) links of the cystine amino acid and sulfonate (-S0 3 ). The formation of sulfonate groups is concen­ trated at the outer most surface where atmospheric oxygen, and UV illumination interact with the hair fiber (1,5). The observed nitrogen is present as a single chemical state, (399.8 eV) due to the amide, (peptide) links between amino-acids. Calcium and silicon were observed as naturally occurring constituents of the hair present in low levels ( 1.0 atom percent) consistent with previous work (4). Electron microscope images show the fibers to have ragged cuticle edges (Figure 2). The definition of the cuticle edges is obscured, particularly at lower magnification, presumably from deposits on the hair surface. BLEACHED HAIR Bleaching treatment gave widely varied results depending upon the time of treatment and the solution composition. Figure 3 is a survey scan of hair fibers after treatment with 3% hydrogen peroxide, at pH 9 for 45 minutes. There is a notable decrease in the about of surface carbon while the features due to 0, N, and S increased. Table II illustrates the surface compositional differences before and after bleaching.