Production of zirconia-based ceramic foams from sol-gel emulsion process

• Grant number: 05/03366-0
• Support Opportunities: Scholarships in Brazil - Master
• Start date: March 01, 2006
• End date: February 29, 2008
• Field of knowledge: Physical Sciences and Mathematics - Chemistry
• Principal Investigator: Celso Valentim Santilli
• Grantee: Marinalva Aparecida Alves Rosa
• Host Institution: Instituto de Química (IQ). Universidade Estadual Paulista (UNESP). Campus de Araraquara. Araraquara , SP, Brazil

Abstract

The main goal of this project is to establish a new route to ceramic foams formation from the gelation of zirconia based hydrosols within water-in-oil emulsion. The hydrosols will be prepared by adding an acidified (HCl) zirconyl chloride aqueous solution to a sulfuric aqueous solution at 60ºC. The hydrosols prepared at ZrOCl2/H2SO4 proportion ratio equal to 15:1 are stable, while that prepared at 3:1 are subjected to a thermostimulated sol-gel transition. This transition causes the viscosity increase and the stability of the emulsified gel, which is prepared by the addition of sulfuric acid, surfactant and oil to the hydrosol. The extraction of the volatiles allows to the ceramic foam formation. By building the ternary diagram water/oil/surfactant, the more adequate composition that gives rise to the emulsion will be determined. Moreover, the physical-chemical parameters that allow to control the porosity, size and connectivity of pores in the ceramic foams will also be determined. During the ceramic foam preparation, the influence of nature and volume of oil, used as micelles filling agent, the concentration and nature of surfactant, and the emulsification route will also be evaluated. The foams microstructure will be followed by scanning electron microscopy, porosimetry, measurements of surface area, average pore size and real and apparent density. (AU)

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

ROSA, Marinalva Aparecida Alves. Preparação de espuma cerâmica à base de zircônia pelo processo sol-emulsão-gel. 2008. Master's Dissertation - Universidade Estadual Paulista (Unesp). Instituto de Química. Araraquara Araraquara.