MASc Candidate University of Toronto Toronto, Ontario, Canada
Abstract: Mixtures of cocamidopropyl betaine (CAPB) and sodium lauryl ether sulfate (SLES) are commonly used in cosmetic and personal care formulas because of their synergistic rheological behavior. The presence of fragrances (solubilized oils), depending on their polarity, may enhance or disrupt this synergism. The HLD-NAC model has been used to understand conditions where oils of different polarities can still be solubilized in SLES + salt solutions without significantly disrupting the viscosity peak in salt curves. The work presented builds on this previous work, first by obtaining the characteristic curvature (Cc) for CAPB and SLES using direct curvature measurements and then using the HLD-NAC model to predict the curvature, structure and viscosity of CAPB + SLES mixtures on their own, and in the presence of solubilized fragrance. The challenges and opportunities with this approach in the design of personal care products will be discussed.
