1999 ANNUAL SCIENTIFIC MEETING 55 The thickness of the water layer in the lameliar phase was analyzed using the quadrupolar splitting in deuterium NMR. Controlled stress rheology was measured on a Bohlin CVO rheometer with a couette measuring system. Results Addition of hydrophobically modified hydroxyethylcellulose (HMHEC) to the surfactant system octanoic acid / sodium octanoate / water dramatically alters its properties. Lying at the interface between surfactant aggregates and water molecules, HMHEC changes the packing of surfactant molecules in miceliar and liquid crystal aggregates. Such behavior results in miceliar-to-hexagonal (L•--E) and micellar-to-lamellar (L•--D) phase transitions. As the number of hydrophobic side chains per polymer is increased, these transitions are more pronounced. In the lameliar mesophases, HMHEC causes a slightly decreased width for the water layer (d,,), as shown by 2H NMR. This effect is stronger than the confinement imposed on the HMHEC by a d,, which is much less than HMHEC's estimated hydrodynamic radius (Rh). The confinement effect may be responsible for creating more defects in the bilayer structures, thereby imparting a D--E transition which may not represent a thermodynamically equilibrated state. All of these activities intensify as the % hydrophobe or the spacer length is increased. When placed under the magnitude of steady shear conditions that might be expected in skin applications, the D phase of this system undergoes a phase transition to a vesicular structure after passing through a mixed phase state. As the aqueous content (or d,,) is decreased, this phase transition occurs at a higher shear rate. Surprisingly, HMHEC has practically no effect on this shear-induced phase transition. For the D phase, then, the plane of slippage must be within the surfactant bilayer under steady shear conditions. We find the opposite to be true for the other lameliar phase of this system (B), previously believed to be composed of either vesicles or Helfrich-type planar bilayers. Our data support the idea that the B phase is a Helfrich lameliar phase and indicate that HMHEC acts to bridge the surfactant bilayers such that higher shear rates are required to cause a phase transition. In this case, then, the plane of slippage must be in the water layer, where the HMHEC resides. • Ekwall, P. Mandell, L. Kolloidz ioo 3% HEC HEC Polymere 1969, 233, 938.

56 JOURNAL OF COSMETIC SCIENCE QUANTITATIVE AND QUALITATIVE MEASUREMENT OF THE ADSORPTION OF CATIONIC HYDROXYETHYL CELLULOSE ONTO KERATIN SURFACES VIA DIRECT POLYMER FLOURESCENT LABELING James V. Gruber', Francoise M. Winnik 2, Andre Lapierre 2, Neela D. Khaloo 2, Niraj Josh •, Aaron Lawrence 2, and Peter N. Konish • •Amerchol Corporation, Edison, NJ 08818-4051 and 2McMaster University, Hamilton, ON L8S 4M1 Canada Introduction The most effective method available to analyze the deposition of cationic hydroxyethyl cellulose [cat- (HEC), Polyquaternium-10] onto keratin surfaces to date has been the use of radio-labeled materials. This method was pioneered by Goddard [1,2]. However, the current lack of availability of these unique radioactive materials has prevented research laboratories from employing them to study the deposition of these cationic materials from surfactant formulations. The labeling of cationic hydroxyethylcellulose using fluoresecent dyes has been reported recently [3]. This development offers a unique opportunity to develop new methodologies for measuring polymer deposition as these fluorescent dyes, covalently attached to the polymer, convert the normally spectroscopically-invisible cat-HECs into species that can be detected by fluorescence techniques. We will discuss our efforts to develop this technology to study the deposition of cat-HECs included in various formulations, their deposition onto hair under standard shampooing conditions, and the quantitative analysis of the amount of polymer deposition. In addition, these unique polymers allow the opportunity to visualize the polymers on individual hair fibers via confocal microscopy. Experimental The methods to attach the fluorescent dye on the cat-HEC and to analyze the labeled polymer have been discussed in detail elsewhere [3]. Virgin blond tresses were washed with a shampoo containing the ingredients listed in Table 1. The polymers employed are listed in Table 2. Each tress was treated with one gram of shampoo at three locations on the tress, washed one minute and rinsed one minute. For multiple wash cycles, each tress was dried with a 1500 watt commercial hair dryer prior to the next treatment cycle. A combination of five virgin blond tresses (except as noted below) (DeMeo Brothers) were shampooed through one or ten wash cycles for each data point. The treated hair was cut at the middle of the tress into one gram sections and the resulting hair specimen was placed into 99 grams of 3% NaOH for 24 hours at room temperature. The resulting pale yellow solutions were filtered to remove any fine non-digested components (virgin blond hair provides the cleanest digested solutions with no detectable residual fluorescence found on the flitrate). The amount of deposited cat-HEC was determined by fluorescence spectroscopy using a standardization curve previously prepared from known concentrations of the fluorescently-labeled cat-HEC used in the shampoo. Deposition amounts are recorded as the mean value and variance in micrograms of polymer per gram of hair. Table 1. Shampoo Ingredients Ingredient % Actives % Solids Ammonium Laureth-(3) Sulfate Ammonium Lauryl Sulfate Cocamidopropyl Betaine DMDM Hydantoin Polyquaternium- 10 Deionized Water 27 28 35 55 100 13.5 4.0 3.0 0.2 0.5 q.s. to 100 Table 2. Polyquaternium-10 Sample Descriptions Polyquaternium-10 Approx. Mw Approx. %N Moles of attached dye/gram of polymer A • 400,000 1.8 4.4 X 10 's B ! 400,000 0.9 1.0 X 10 -4 C: 900,000 1.8 4.7 X 10 -s- 7.9 X 10 -s tDye attachment data provided for one labeled polymer. 2Dye attachment data provided for a combination of five labeled polymers with various values between high and low shown in Table. t Current Address: Ralph Lauren, Terminal Ave., Clark, NJ 07066