Effect of mechanical activation of montmorillonite on the intercalation efficiency of polyhydroxyaluminum cations in the formation of pillar structure

Abstract

The effect of mechanical treatment of natural montmorillonite (MM) on the intercalation efficiency of polyhydroxoaluminum cations in the synthesis of pillar structures (PSs) is studied. Textural and adsorption properties of the materials are characterized via X-ray diffraction, photometry, scanning electron microscopy, laser diffraction, electrophoretic light scattering, and nitrogen adsorption-desorption experiments. It is found that, compared to the conventional method, which allows obtaining Al₂O₃-pillar montmorillonite, a small MM particle size (about 100 nm) in an aqueous suspension plays a key role in the increased cation exchange capacity of the mechanically activated MM and textural characteristics of the resulting PSs and not Na⁺-enrichment. It is shown that MM mechanical pretreatment enables us to increase a specific surface area and the total pore volume of Al₂O₃-pillar montmorillonite to S _BET = 169 m²/g and V _total = 0.25 cm³/g when compared to 140 m²/g and 0.19 cm³/g in the samples without mechanical activation.