Dual-purpose facial cleanser based on the L3 phase

Abstract

In order to fabricate a mild cleanser that performs the dual function of cleaning the facial skin and removing the make-up in a single step, phase diagram of sucrose laurate (SL)/propylene glycol monolaurate (PGML)/water systems is determined at 25℃. In the present work, we perform detailed investigations on the development of the micelles and the L₃ phase employing cryo-SEM microscopy and SAXS technique. A transition from the ellipsoidal micelles to the “pseudo-oblate” micelles, induced by the incorporation of PGML, is observed within the micellar region. As the SL/PGML mass ratio ${\psi }_{\mathrm{SL}/P}$ continues to decrease, a bilayer continuous phase (namely L₃ phase) occurs. Especially, a well-developed L₃ phase is found to exist predominantly in the systems with surfactant concentration ($W_S$) in the range of 0.05–0.15 as well as ${\psi }_{\mathrm{SL}/P}$ around 65/35. A strong shear-thinning behavior is observed for these L₃ phases during the steady shear tests. Subsequent dynamic frequency sweeps indicate that the elastic modulus of L₃ phase prevails over the viscous one over a large range of frequency, revealing the predominant presence of the sponge-like web. And its remarkable thermal stability is confirmed by the oscillatory amplitude test performed at 55 ℃. These L₃ phases exhibit weak gel-like behavior and demonstrate excellent cleansing efficacy in the removal of both hydrophilic and oily impurities, which make them great for use as a dual-purpose facial cleaner.