Kalinichenko E. The kinetics and the mechanism of the dehydroxylation in inorganic layered materials on the magnetic resonance data

The experimental and the theoretical studies of thermal destruction of structural OH-groups (dehydroxylation) in muscovite, kaolinite, gibbsite and brucite have been performed. Original, exposed to gamma-irradiation or at a constant electrical field samples have been studied. Thermal vibrations of the nearest lattice ions and reoriented vibrations of the OH-group have been shown to result in the essential reduction of the proton potential barrier in muscovite at dehydroxylation temperatures. Gamma-Irradiation (by 108 Gy dose) accelerated the dehydroxylation of kaolinite and gibbsite and slowed down - brucite. The last has been explained by formation of more thermostabile carbonate phase on crystallite surfaces under irradiation, what at the first time has been established in the present work. The mathematic model, which describes hydrogen isotope moving into layered OH-bearing materials at ambient conditions, has been developed. This model fits well experimental data on tritium accumulation. The local-level mechanism of dehydroxylation has been cleared - a proton overcomes the potential barrier from one OH-group to the nearest, when barrier parameters are decreased essentially as a result of vibrations of great structural regions and, in a lower degree, of reoriented OH-group vibrations. The obtained results can be used to solve the applied problems of selecting and creating of radiationstable materials, in particular, with large tritium sorption capacity.