Preparation of rutile TiO2@avobenzone composites for the further enhancement of sunscreen performance

Abstract

It is well known that organic avobenzone and inorganic TiO₂ are applied to shield UVA and UVB, respectively. However, some of the disadvantages of the individual components are inevitable in sunscreens. Herein, avobenzone was coated on the surface of pretreated TiO₂ for the preparation of a TiO₂@avobenzone broad-spectrum sunscreen. The as-prepared products were characterized via XRD, FTIR, TG and SEM. The organic film-layer was evenly encapsulated on the surface of the pretreated TiO₂ to assemble a core–shell structure. Subsequently, TiO₂@avobenzone was applied to a formulation and the properties of the obtained emulsion were evaluated via droplet size distribution analysis, HPLC and an ultraviolet transmittance analyzer. The results show that TiO₂@avobenzone possesses more excellent dispersity, lower degradation rate and higher SPF value as compared to the individual components in the formulated emulsion, and thus, TiO₂@avobenzone could be used as a potential candidate for sunscreens.