Synthesis and Properties of Heat-Stable Expanded Smectite and Vermiculite1

Abstract

When aqueous dispersions of N a +-smectite or n-butylammonium-vermiculite react with sulfate salts ofFe(Il), Co(lI) , or Ni(II) bipyridyl or 1, lO-phenanthroline complexes in excess of the cation-exchange capacities, intersalated phases with spacings of about 29.5 A are obtained. Thermal decomposition of the intersalated complex cations affords expanded phases with a d(OOI) spacing near 18 A for the smectites and near 28 A for the vermiculites. These phases are stable to temperatures of at least 550°C. Nitrogen surface areas of the fired products are as high as 400 m'/g.