Supercritical drying of barium titanate alcogels

Aerogels are nanostructured materials containing a large volume of interconnected porosity, which are generated by the supercritical drying of sol-gel systems. Barium metal and titanium butoxide derived sol has been used to generate transparent alcogels. Supercritical drying using liquid carbon dioxide generates an aerogel structure, which on firing crystallises to barium titanate. The chemical evolution has been followed from the sol to the final fired product using FTIR, whilst the fired microstructure has been studied using transmission electron microscopy. The work is being carried out with the aim of utilising the large amount of interconnected porosity to create 3-3 functional ceramic-polymer composites.