Ab Initio Simulation of the IR Spectrum of Hydrated Kaolinite

Abstract

The hydration of the basal surfaces of kaolinite is studied by theoretical methods. The cluster method was used to simulate the positions of atoms. The positions of the atoms of the basal surfaces of dry and hydrated minerals are optimized by minimizing the total energy in the Hartree–Fock approximation. The adsorption energies of water molecules were calculated taking into account the fourth-order correlation corrections of Møller–Plesset perturbation theory. The formation of the IR spectrum of kaolinite in the range of wave numbers 2500–4500 cm−1 is studied. The experimentally observed effect of the change in relative intensity and position of the band with a change in the moisture content of the sample is interpreted.

Data on FTIR spectra of the clays KGa-1b and STx-1b and their mixtures at different moistures

“…These data were used in the article “Study of hydration of kaolinite and montmorillonite mixture by IR spectroscopy” [2] , to study the dynamics of the formation of water layers on the surface of clay particles. The data presented can be used to test experimental methods for studying the adsorption properties of mixtures, and to create new laboratory methods for determining the plastic properties of soils [3] . In addition, the data presented can be used to verify theoretical approximations and computer models for calculating the structure and electronic properties of minerals and their mixtures [4] .…”

Surfaces and Interfaces of Clay Minerals

“…This work analyses interaction energy, basal spacing, and distribution of hydrogen bonds in the interlayer of MLCs containing K + and Na + with Na-montmorillonite of different water contents in order to better understand the swelling mechanisms of such clays. Ab initio Hartree-Fock's theoretical study of the interaction of water molecules with the basal surfaces of kaolinite was performed by Yavna et al [2]. The authors investigate the electronic structure and infrared spectra of kaolinite in the range of 2500-4500 cm −1 to explain the surface hydration of 1:1 clay minerals.…”