Investigation of the processes of thermal decomposition and rehydration of Mg-Al LDH obtained by solid-phase synthesis

Mg-Al LDH samples of Mg4Al2(OH)12CO33,85HO composition were obtained by solid-phase synthesis. It was found that as a result of heat treatment with subsequent rehydration, synthesized Mg-Al LDH samples are reduced to the composition Mg4Al2(OH)12CO33HO, regardless of the medium and duration of treatment. It has been shown that rehydration in NaHCO3 solutions contributes to an increase in the crystallite sizes of Mg-Al LDH samples being recovered, which is not observed when Mg-Al LDH is reduced in an aqueous medium. An increase in the duration of hydration in NaHCO3 solutions leads to an increase in the crystallites of Mg-Al reduced LDH, which is not observed during rehydration in an aqueous medium.