Hydrothermal syntheses of a silicate structure comprising a single tetrahedral layer, known as ilerite, were conducted in the presence of tin (SnCl4·5H2O) as a heteroatom. The main aim of the study was to investigate the influence of the above-mentioned compound on the resulting material, as well as the possibility of isomorphous replacement of Si by Sn atoms. For comparison, unmodified ilerite, ilerite impregnated by SnO2, and ilerite synthesized in the presence of Al (aluminum isopropoxide) were also used. The ilerite structure observed was that of Na-ilerite. Syntheses of samples with various Sn/Si ratios (up to the value of 0.01Sn/4Si) and Al/Si ratios (up to the value of 0.005Al/4Si) resulted in a magadiite structure. Synthesis methods applied to Sn-modified materials were found to be unsuitable for the introduction of tetrahedrally substituted Al. The characterization methods used were X-ray diffraction (XRD), temperature-programmed reduction (TPR), and diffuse reflectance infrared fourier transform (DRIFT) spectroscopy. and these indicated the presence of metal oxide species on the surfaces of the crystals, in addition to a small degree of replacement of Si by Sn or Al in the tetrahedral layers.

Hydrothermal syntheses of the magadiite, a layered silicate structure, were conducted in the presence of a heteroatom source (SnCl4.5H2O) with the intention of investigating its influence on the resulting material, as well as the possibility of isomorphous replacement of Si by Sn atoms in the abovementioned structure. For comparison, unmodified magadiite, Al-containing magadiite, and impregnated magadiite were synthesized. The magadiite structure was identified for samples with Sn/Si ratios up to 0.015. Synthetic methods applied to Sn-modified materials were found to be unsuitable for the introduction of Al. The characterization methods used were X-ray diffraction, temperature-programmed reduction, and 29Si magic angle spinning nuclear magnetic resonance and these revealed the substitution of Si by Sn in the silica layers. No additional acid centers on the surfaces of the modified samples were detected, suggesting the presence of the desired four-coordinate Sn in the silica layers.

The evolution of textural properties of Na/Ca-bentonite from Wyoming (MX-80) was studied by adsorption of nitrogen, water vapour, and ethylene glycol monoethyl ether. Clay suspensions were heated at 80 and 300ºC for up to 9 months in the absence of or in the presence of Fe and/or Fe oxides. The treatment without Fe did not change the textural properties of the samples significantly. The treatment at 80ºC in the presence of Fe resulted in a considerable increase in the external surface areas of the samples. The total and external surface areas and swelling capacities of the samples decreased following the treatment at 300ºC in the presence of Fe and Fe oxides. In the case of larger additions of Fe, the treatment at 300ºC resulted in a considerable decrease in the total and external surface areas and swelling capacity of the sample and in the formation of a network of large-size pores, in which all the pores were connected.