Preparation and characterisation of analcime by X-ray and SEM.

Martina Novotná¹, Alexandra Kloužková² and Jaroslav Maixner³

¹Laboratory of Inorganic Material, Institute of Inorganic Chemistry, AS CR, Praha, Czech Republic

²Department of Glass and Ceramics, Institute of Chemical Technology, Praha, Czech Republic

³Central Laboratories, Institute of Chemical Technology, Praha, Czech Republic

Leucite( KAlSi₂O₆) based materials having high fracture toughness and being useful for making ceramic-fused-to-metal restorations [1] represent a very promising composite material for dental applications. For its extensive use is, however, necessary to develop a suitable and reproducible technology of its preparation. This can be achieved either by the direct hydrothermal synthesis of leucite or by the ion-exchange of analcime (NaAlSi₂O₆·H₂O) as a precursor. The purpose of this study was to investigate the synthesis of analcime and the effect of principal factors influencing its crystallisation. Analcime powders were prepared by hydrothermal synthesis in a Teflon lined stainless steel autoclave. The role of the composition of the reaction mixture (source materials, silica/alumina ratio, OH^- concentration, and water concentration), reaction temperature and time was studied.

[1] J.R.Kelly, Annu. Rev. Mater. Sci., 27, (1997), 443-.