[3PS-147]
Water-in-Water Emulsions for Efficient and Uniform UV Blocking
발표자이은석 (서울과학기술대학교)
연구책임자김규한 (서울과학기술대학교)
Abstract
In this study, we present an oil-free sunscreen platform based on an aqueous two-phase system (ATPS)-derived water-in-water (W/W) emulsion composed of biocompatible polymers and stabilized by inorganic particles. Using a PVA/DEX ATPS incorporating a water-soluble UV filter (PBSA) and TiO₂ particles, stable W/W emulsions were formed via particle adsorption at water–water interfaces. Compared to conventional TiO₂ suspensions, the W/W emulsions exhibited significantly enhanced UV protection and markedly improved uniformity upon application. In vitro SPF measurements demonstrated SPF values of approximately 40 at a TiO₂ concentration of 15 w/v%, showing superior performance to commercial sunscreen formulations evaluated under identical conditions. Rheological characterization revealed balanced viscoelastic properties (tan δ ≈ 1), enabling uniform spreading while maintaining structural integrity.