OBTAINING, PROPERTIES, AND PROSPECTS FOR USE OF Al30-PILLARED MONTMORILLONITE

Abstract

Over the past decade, the Department of Technology of Ceramics and Electrochemical Production has been conducting research related to the obtaining of new types of refractory non-metallic and silicate materials. One of the promising directions is focused on the modification of natural clay minerals in order to enhance their sorption, catalytic, electrolytic, optical and other properties. This article presents the results on the functionalization of pillared clays. Using the "giant" aluminum polycations [Al30O8(OH)56(H2O)24]18+, Al30-pillared montmorillonite (Al30-PMM) was obtained for the first time by the intercalation method, its structural and textural properties were characterized, and its functionality was studied. When identifying Al30 polycations and studying the physicochemical properties of Al30-PMM in comparison with the previously known Al13-PMM and the original natural montmorillonite (Dash-Salakhly deposit, Azerbaijan), the following methods were used: photometry, infrared and fluorescence spectroscopy, electron microscopy, static light scattering, NMR spectroscopy, porosimetry, dynamic laser beam scattering, X-ray diffractometry, thermogravimetric and differential thermal analysis, impedancemetry and high-temperature mass spectrometry. The effect of preliminary mechanical activation of the aluminosilicate matrix on the efficiency of intercalation of aluminum polycations has been studied. An anomaly in the temperature dependence of the current density of the thermal emission of alkali metal ions from the Al30-PMM surface was found, interpreted from the point of view of the phase transformation of pillars. The patterns of adsorption on Al30-PMM of organic dyes of cationic and anionic types in aqueous solutions, carotenoids and fatty acids in vegetable oil, as well as humic acids, for which, in combination with Al30-PMM, the detoxifying ability with respect to oil in water was examined. A new method of electrolytic modification of montmorillonite is proposed, which consists in doping with lithium and sodium ions of nanocavities of pillared montmorillonite. It has been shown that hydrothermal cohydrolysis of aluminum and cerium salts makes it possible to synthesize large-sized polyhydroxocomplexes that improve the textural properties of pillared montmorillonite compared to Al30-PMM. In general, the fundamental principles of the formation of a layered-columnar structure identified in the work can be used to design innovative materials based on layered systems by varying the sizes and chemical composition of intercalated ions. For citation: Butman M.F., Ovchinnikov N.L., Kosenko N.F., Filatova N.V., Pogonin A.E. Obtaining, properties, and prospects for use of Al30-pillared montmorillonite. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2023. V. 66. N 7. P. 159-172. DOI: 10.6060/ivkkt.20236607. 6833j.