WELL-ALIGNED SAPO-5 MEMBRANE - PREPARATION AND CHARACTERIZATION

Membranes of well-aligned SAPO-5 crystals were grown on floating anodi c alumina by a two-step microwave hydrothermal synthesis. Various sets of samples with different silicon contents in reactant gels and diffe rent reaction times in secondary microwave hydrothermal heating were s tudied. The degree of preferred orientation along the c-crystal axis o f the AFI structure and the zeolite coverage on alumina support were a nalyzed by XRD and SEM. FTIR microscopy was employed to study lattice vibrations in membranes of aligned AFI crystals as well as in AFI sing le crystals, while secondary ion mass spectroscopy and Si-29 MAS NMR w ere used to determine the Si distribution and its state in SAPO-5 prod ucts. (C) 1998 Elsevier Science B.V. All rights reserved.