Mullite is a ceramic material with great technological applications. It has been used in pieces submitted to great mechanical efforts due to its chemical, physical and mechanical properties. Its physical chemical properties are related to synthesis method. Sol-gel is method for synthetizing mullite that makes it possible to control its properties. Sol-gel process can be divided in two methods: monophasic and diphasic. The synthesis of mullite by sol-gel process will be studied in this project using a new route: using glycols as solvents. During master degree work, we observed that is possible to obtain mullite at low temperature (1000 ºC) using glycol ethylene, sodium metasilicate as source of silica. Now, the influence of linear glycols with different sizes (2 to 6 carbon atoms) and number of OH in the chain on the kinetics of mullite crystallization will be studied. The chemical bonding between organic and inorganic compounds will be studied by FTIR and RAMAN. The crystallization study will be conducted by DTA, DRX and FTIR. The kinetic parameters will be determined by thermal analysis. DRX will be used to identify the crystallographic phases and quantify the mullite crystallization by internal standard method. FTIR will be used to determine the value of x (related to alumina content). The morphology will be studied by SEM.
News published in Agência FAPESP Newsletter about the scholarship: