SYNTHESIS OF MESOSTRUCTURED LAMELLAR ALUMINOPHOSPHATES USING SUPRAMOLECULAR TEMPLATES

The liquid-crystal templating approach for the synthesis of mesostruct ured materials was extended to aluminophosphates. A variety of lamella r AlPO4 phases with d spacings in the nanometer range were prepared in the presence of long-chain primary and tertiary amines. A systematic study of the influence of the gel composition was carried out. AlPO4 m aterials were characterized by various techniques including XRD, TEM, electron diffraction, and Al-27, P-31, N-15, and C-13 NMR. The gel com position has a drastic influence on the nature of the product formed a nd on the coordination of aluminum and phosphorus in the final ''cryst alline'' phase. These lamellar AlPO4 phases were not stable under calc ination conditions and the templating surfactant could not be removed by solvent extraction.