Síntese de Nanoestruturas de ZnO e TiO2 Via Método Sol-Gel Proteico e Reação de Combustão para Aplicação em Fotoproteção

Abstract

Sunscreens are classified as chemical (organic) filters and physical (inorganic) filters. Inorganic filters consist of metallic oxides and have a broad spectrum of protection that act by reflecting, dispersing and absorbing UV radiation. Zinc oxide (ZnO) and titanium dioxide (TiO2) belong to the class of semiconductor materials, have a mechanism of absorption of UV radiation that involves transitions of electrons between the valence and conduction bands, exhibit exceptional effectiveness in the protection against radiation UVA and UVB. However, in order to be feasible this application requires that the method of obtaining these materials is associated with a nanoparticle technologist, since its use in formulations without previous control of the particle size promotes the formation of a white film on the skin, characteristic which is not well accepted by the consumer. The mechanism of synthesis directly influences the properties and size of particles. In this work, ZnO and TiO2 were produced by two routes of synthesis: protein sol-gel method and combustion reaction. The material obtained was characterized by X-ray diffraction, Uv-VIS Spectroscopy, Photoluminescence and Scanning Electron Microscopy. In the ZnO obtained by combustion reaction the presence of a secondary phase was observed that in the spectrum of absorbance also exhibited a band referring to the presence of impurities. The TiO2 obtained by the combustion reaction exhibited majority formation of the rutile phase, whereas in the TiO2 obtained by the protein sol-gel method showed formation of the anatase phase. Nevertheless, formation of nanoparticles was achieved for both synthetic routes.