By adsorption of monosilicic acid on aluminum hydroxide, an amorphous aluminosilicate (AAS) of Si/Al ratio of 1/3 was formed. When the AAS was heated to 1000°C, mullite (3Al2O3 · 2SiO2) crystallized directly without the formation of a spinel phase. It was clearly evidenced that correct adjustment of three factors, the Si/Al ratio, the proportion of 4- and 6-coordinated aluminums, and the single environment of a SiO4-4 unit (no Si-O-Si bond), is important for the direct mullitization from AAS.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering