Synthesis by sol-gel of SiO2 matrixes: effect of different acid catalysts on the microstructure

NOE J MORALES; CRISTIAN HUCK IRIART; SILVIA GOYANES; MARIA L HERRERA; ROBERTO J CANDAL

Campinas

Congreso; Activity Report 2011 Brasilian Sincrotron Light La boratory; 2011

CNPEM/LNLS

SiO 2 hidrogels and xerogels are important materials for the development of bioinorganic systems, adsorbents, catalysts supports and others. The microstructure of the SiO 2 plays a key role in these applications. Sol-gel process is a versatile techniques for the synthesis of SiO 2 hydrogels and xerogels. The microstructure depends on the synthesis conditions. It is well known that the acid catalyst concentration play an impor-tant role in the sol to gel transition, but the effect of the type of acid on the gelification process and microstructure is not so well known. With the aim to produced better SiO 2 matrixes as catalyst supports we explored the effect of different acids on the microstructure of SiO 2 gels and xerogels. Character-ization is based on Small Angle X ray Scattering (SAXS), a powerful tool to analyze the microstructure of non crystalline solids, BET sorptometry and low resolution nuclear magnetic resonance spectroscopy (H-RMN)