Monitoring the Process of Crystallization and Determination of the Degree of Crystallinity of NaA Zeolites by Infrared Spectroscopy

Abstract

The course of crystallization and the degree of crystallinity of NaA zeolite, as well as its modified forms after treatment with HCl can be monitored by infrared cpectroscopy. As internal standard the band at 470cm^?1, due to vibrations in the SiO₄ tetrahedron may be used. During the crystallization process the amount of double fourfold rings (D4R) in the alumino-silicate gel increases which can be followed by the IR band at 560cm^?1. The ratio of intensity of this band and the one at 470cm^?1 increases in the course of crystallization.