ANA and GIS zeolite synthesis directly from alumatrane and silatrane by sol-gel process and microwave technique

Alumatrane and silatrane were successfully used as precursors to produce aluminosilicate via the sol-gel process. Due to their ability in retarding hydrolysis process, forming meso-porous material was easier. Both NaCl and NaOH can be used as hydrolysis agents, however, NaOH had highly influenced crystalline formation. The higher NaOH concentration, the better crystalline formation was observed. Gel transformation was an endothermic reaction. The maximum transformation occurred at 106 degreesC, as determined by differential scanning calorimetry (DSC). By using NaOH/H2O as a hydrolysis agent and treating amorphous metal oxide gel by microwave technique, the crystalline aluminosilicate was formed and narrow particle size distribution was obtained. By fixing the ratio Of SiO2, Al2O3, Na2O and H2O at 1:0.25:3:410, GIS was synthesized at hydrothermal treatment of 3 h at 110 degreesC, while analcium (ANA) was produced at 130 degreesC for 8 h. GIS obtained had 4.55 mum in size while ANA's size was 9.96 mum. (C) 2002 Elsevier Science Ltd. All rights reserved.