Interaction of humic and fulvic acids with nanoclusters of aluminum hydroxo cations on the surface of kaolinite according to IR spectroscopy data

We chemically modified the surface of kaolinite with nanoclusters of aluminum hydroxo cations. We have determined their composition and sizes. We have used IR spectroscopy to establish the interaction between the carbonyl and -diketone groups of fulvic and humic acids with the Lewis acid sites: coordination unsaturated Al³⁺ cations of the Al₁₃ nanoclusters. We have obtained spectral evidence for hydrogen bond formation between the carboxyl groups of fulvic acid and the hydroxyl groups of the aluminum hydroxo cations.__________Translated from Teoreticheskaya i Éksperimentalnaya Khimiya, Vol. 41, No. 1, pp. 45–49, January–February, 2005.