Fourier-transform infrared spectroscopic measurement of salt imbibition by zeolites

Abstract

FTIR measurements have confirmed that when NaY is treated with an aqueous solution of NaNO₃, adsorption of salt on the exterior surfaces of the crystals is substantial. Experiments with sodalite show the effect even more clearly. It is proposed that external adsorption, rather than salt inclusion, may be the reason for the sensitivity of synthesis procedures to the presence of dissolved salts.

Samples of NaY with almost the same chemical composition, water content and X-ray diffraction pattern but which differ in crystallite size were found to have distinctly different IR absorption, both in the water stretching region, and in the framework-vibration region of 1050–1150 cm^–1 which is usually classed as structure-sensitive.