Development of filters and sunscreens from the intercalation of organic filter in lamellar double hydroxides

• Grant number: 12/20701-0
• Support Opportunities: Scholarships in Brazil - Master
• Start date: February 01, 2013
• End date: January 31, 2015
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Inorganic Chemistry
• Principal Investigator: Marian Rosaly Davolos
• Grantee: Gustavo Pereira Saito
• Host Institution: Instituto de Química (IQ). Universidade Estadual Paulista (UNESP). Campus de Araraquara. Araraquara , SP, Brazil

Abstract

The use of sunscreens is essential to protect skin against sun damages. The study of the organic and inorganic filters as well as colloidal systems that compose sunscreens requires scientific research.This work aims the development the new UVA/UVB filters through organic filter intercalation in inorganic matrices in order to obtain sunscreens with better performance: low irritability, high chemical and photo stability and high sun protection factor. Among the inorganic matrices, layered double hydroxides (LDH), which are hydrotalcitetype compoundscan be able to incorporate negative species in the layered region. Besides its low toxicity and high biocompatibility, LDHs combined with organic filters result in hybrid materials showing synergistic properties such as chemical stability and promising properties for use as UVA/UVB filter in sunscreens.The layered double hydroxides [Zn1-xAlx(OH)2](An-)x/n.zH2O will be used as inorganic matrix and the hexyl 2-(4-diethylamino-2-hydroxybenzoyl)-benzoate (Uvinul-A-PlusÒ) compound as organic filter to obtain hybrid materials. The samples will be characterized by X-ray powderdiffraction, thermal analysis, infrared absorptionand Raman scattering vibrational spectroscopies, electronic absorption spectroscopy in the UV-VIS, and scanning andtransmission electron microscopies. The hybrids will be used in sunscreens formulations and they will be characterized byrheological measurements and UV-VIS absorption electronic spectroscopy. (AU)