Composition, structure, and sorption capacity of natural aluminosilicates

Synthesis and Investigation of the Properties of Biphasic Hybrid Composites Based on Bentonite, Copper Hexacyanoferrate, Acrylamide and Acrylic Acid Hydrogel

“…Such substitutions are non-stoichiometric and create a deficit in positive charges, which are compensated from interlayer positions predominantly by monovalent, and less often by divalent, large cations. The general composition of layers with a 2:1 structure, which differ in layer charges, can be represented by the formula [ 33 , 34 ]: where x + e + z is the charge of the layer, which is usually determined from the recalculation of chemical analyses or from capacity values, although it is not possible to obtain an objective estimate in this case [ 34 ].…”

“…The Mössbauer spectra of iron-containing bentonite are a superposition of three quadrupole doublets ( Figure 2 ). The spectrum of Fe 2+ is decomposed into a doublet at the M1 and M2 positions, the first of which corresponds to octahedrons with OH − groups in the trans-position, whereas the second one characterizes the location of hydroxyl groups in the cis-position of octahedrons, with twice as many octahedrons in M2 position than in M1 [ 32 , 33 ]. The well-resolved doublets appear with chemical shifts at δ = 1.225 and 1.137 mm/s and quadrupole splitting Δ = 1.785 and 2.750 mm/s, respectively.…”

On the possibility of elemental analysis of solid crystals by the X-ray diffraction method

“…Elemental analysis based on the X ray diffraction method was used for studying typical natural alumi num silicates (clays from the Lukovskii deposit, Pskov oblast) burnt by different temperatures [5]. X ray phase analysis of the samples was carried out using the Dron 7 diffractometer with a copper anode (λ = 1.5406 Å) and with a parabolic mirror mated with an X ray tube, which ensures 100% suppression of the emission line of CuK β in the X ray spectrum with wavelength λ = 1.3922 Å and a paraxial X ray beam incident on the sample with a divergence smaller than 0.01°.…”