Search

The methods of scanning and transmission electron microscopy, energy-dispersive analysis, and electron energy loss spectroscopy are used for the study of the interaction of soluble sodium and magnesium sulfates, as well as sodium chloride (in the presence of Na and Mg sulfates), with clay minerals: kaolinite and smectite. It is shown that the interaction of clay minerals with salt solutions initiates the reorganization of crystallites of the minerals and results in the formation of clay-salt microaggregates. The manifestation of the formation of clay-salt microaggregates and their composition, size, shape, and particle-packing state depend on the nature of the minerals and the properties of the salt participating in the interaction. In addition, the interaction of sodium chloride in the presence of sulfates results in the formation of peculiarly shaped pen tagonal clay–salt ultramicroaggregates. Their microdiffraction patterns are characterized by the presence of reflections corresponding to fivefold rotational symmetry; this may be evidence of their quasicrystalline structure.