Ceramics-Silikáty 45 (2) 43-47 (2001)

SYNTHESIS OF ALUMINA-PILLARED FLUORINE MICAS USING POLY(VINYL ALCOHOL) AS A TEMPLATE AND THEIR POROUS CHARACTERISTICS 

T. Yamaguchi, A. Shirai, S. Taruta, K. Kitajima 

Synthesis of alumina pillared fluorine micas has been undertaken using synthetic high layer-charged expandable fluorine mica and hydroxoaluminum solutions with different solution loadings under the presence of poly(vinyl alcohol) (PVA) to obtain microporous solids having high thermal durability. The basal spacings and surface areas of the products depend on the solution loading. The optimal solution loading in this study was 24 mmol Al/g mica. The products thus obtained gave the large basal spacing of 2.7 nm at 500 °C and the maximum surface area of 403 m² g^-1 at 600 °C. The surface area of the product was above 300 m² g^-1 even after heating at 800 °C, showing high thermal durability. Pore size distribution of the products proved the existence of micropores. Sintered bodies of the alumina-pillared micas were obtained by firing at 500-700 °C using pressed powder compacts of the pillared micas. They were machinable and retained porous characteristics.