JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY, cilt.58, sa.1, ss.6-11, 2011 (SCI-Expanded)
Diphasic gels prepared by mixing freshly prepared polymeric silica and polymeric boehmite sols through a modified Al-alkoxide route in mullite compositions led to the crystallization of mullite upon heat treatment at 775 A degrees C. Mullite formation was observed at a 100 A degrees C higher temperature when diphasic gels were formed by mixing aged polymeric sols containing about 2 nm in diameter boehmite species. These relatively low mullite formation temperatures were attributed to the nanoscale sizes of the polymeric species of the two amorphous phases present in the diphasic gels.