EFFECT OF THE ADDITION OF METHYLENE-BLUE TO THE REACTION MIXTURE FOR THE HYDROTHERMAL SYNTHESIS OF ALUMINOPHOSPHATE MOLECULAR-SIEVES ON THEIR MORPHOLOGY

The morphology of aluminophosphate hosts prepared by hydrothermal synthesis with the addition of methylene blue (MB) to the reaction mixture was compared with that of dye-free samples by means of adsorption and electron microscopy methods. With AlPO4-5, SAPO-5, and FAPO-5 (AFI structure type), no effect of the addition of MB has been found. With AlPO4-11 (AEL structure type), MB has caused a 50% contamination with some nonadsorbing material. With AlPO4-20 and SAPO-34 (SOD and CHA structure types), MB strongly influences the morphology of crystals.