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Obtaining highly ordered mesoporous silica from rice husk ash and sugar cane bagasse ash

Grant number: 12/07848-2
Support type:Scholarships in Brazil - Master
Effective date (Start): June 01, 2012
Effective date (End): February 28, 2013
Field of knowledge:Physical Sciences and Mathematics - Chemistry - Inorganic Chemistry
Principal Investigator:Jivaldo do Rosário Matos
Grantee:Juliana Ferreira de Oliveira
Home Institution: Instituto de Química (IQ). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The rice husk (RH) is a spinoff of the rice industry and contains silica in its composition. The burning of this material can be performed, among other reasons, for energy generation. Disposal of the husks or its ashes causes environmental impact, due to their low density. The sugarcane bagasse (SB) also presents silica as one of its constituents. The resultant energy from its burning is used for the supply of sugar and ethanol plants. Also, the disposal of the generated ashes is problematic. The isolated silica from these sources can be used for the synthesis of highly ordered mesoporous silicas (HOMSs), replacing tetraethyl orthosilicate, a source of synthetic silica, which is costly obtained, in addition to providing environmental and health risks. The HOMSs are materials with potential for many applications, especially the use as catalyst supports, adsorbents and support for drug encapsulation. Because of these potentialities, this work aims to obtain HOMSs, employing silica isolated from the SB and RH, thus contributing to solve the problem of disposal of residues generated by the industrial sector. The raw materials and the ashes will be characterized by physic-chemical and analytical techniques, such as TG/DTG, DSC, elemental analysis (C, H, and N), infrared spectroscopy, XRD and X-ray fluorescence. Properties of HOMSs will be evaluated based on the results of SEM and TEM, isotherms of adsorption/desorption of nitrogen and SAXS-RDC. (AU)