Spectroscopic studies of different aluminosilicate structures

The applicability of the MIR spectroscopy for aluminosilicate structures description of some natural zeolites has been shown in this work. The suitability of the spectra for a "convenient" recognition and identification of the kind of SiO4 and AlO4 tetrahedra rings predominating in a given zeolite structure has been described. The interpretation process was supported by the decomposition of the spectra into component bands. The estimation of Si:AI ratio in zeolites and the degree of ordering in the sequence of both building space framework tetrahedra can be done on the basis of parameters (band position and intensity) of the main bands due to SI(AI)-O bond vibrations. The results based on the spectra of zeolites were then compared with the data obtained in the previous works on potassium aluminosilicates (also having framework structures thought not classified as zeolites) and ring silicates (containing isolated silicooxygen rings). Such comparison allows to draw more general conclusions relating to the interpretation of MIR spectra of different silicate structures. (C) 1999 Elsevier Science B.V. All rights reserved.