ISSN 1017-2548(Print)
ISSN 2234-8530(Online)
Volume 37, Number 10
JKCSEZ 37(10)
August 20, 1993 

Influences of crystallization time and H2O / Al2O3 ratio of the reaction mixtures on the synthesis of AlPO4-5 molecular sieve have been studied by X-ray powder diffraction, nitrogen adsorption, scanning electron microscope (SEM), and solid state 27Al magic angle spinning nuclear magnetic resonance (MAS NMR) techniques. The degree of crystallinity of AlPO4-5 follows a sigmoid pattem as crystallization time increases. The induction period is shorter than 1 h when the crystallization process is carried out at 150℃. The conversion of reactants to product, AlPO4-5, can be clearly observed, and all of the determined physical properties change abruptly after about 2 h. It is found that increase in H2O / Al2O3 ratio of the reaction mixtures not only changes the crystal morphology from aggregates to hexagonal single crystals, but also results in the formation of longer AlPO4-5 crystals.