Nano Research & Applications

Effectiveness in UV absorption of hierarchical nano ZnOmicroTiO2 composites with photodegradation inhibition

17^th Edition of International Conference on Emerging Trends in Materials Science and Nanotechnology
April 26-27, 2018 Rome, Italy

J J Reinosa

Institute of Ceramics and Glass, Spain

Posters & Accepted Abstracts: Nano Res Appl

DOI: 10.21767/2471-9838-C1-009

Abstract

Nowadays, sunscreens are formulated by using TiO2 and ZnO nanoparticles because they are efficient inorganic UV filters. In fact micro sized TiO2 and ZnO have been increasingly replaced by TiO2 and ZnO nanoparticles in order to solve the cosmetic drawback of the white opaque sunscreens apart from the higher yield that nanoparticles suppose. Also the aggregation state of the particles in sunscreens is related to the solar protection factor (SPF) of the final emulsion. In this sense, dispersed nanoparticles into sunscreens increase the SPF value, but it means a possible leading to their incorporation into the stratum cornea, the outer layer of the skin. Moreover, when TiO2 is irradiated produces free radicals which are implicated in a number of potential health issues such as skin aging because of the formation of reactive oxygen species (ROS). In this work, composites combining TiO2 micro particles and ZnO nanoparticles have been achieved by using several synthesis and dispersion methods. It has been demonstrated by the incorporation of the different composites into sunscreens that the presence of nanoparticles anchored over TiO2 micro particles allows increasing the efficiency of nanoparticles but decreases the possible health problems by their absorption as nanoparticles. The aim of these new composites is to gain the advantages of inorganic nanoparticles avoiding their potential drawbacks. Hence, the combination of both oxides provokes higher SPF value and lower photodegradation, in comparison with TiO2 micro particles. Moreover, the disposition of ZnO and TiO2 particles means a positive synergy by the recombination of photo induced electrons holes, which decreases the formation of free radicals. jjreinosa@icv.csic.es