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 synt hesis 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 st ructure type), no effect of the addition of MB has been found. With Al PO4-11 (AEL structure type), MB has caused a 50% contamination with so me nonadsorbing material. With AlPO4-20 and SAPO-34 (SOD and CHA struc ture types), MB strongly influences the morphology of crystals.