Effect of the Composition of Initial Components and the Conditions of Activation on the Mechanochemical Synthesis of Magnesium–Aluminum Layered Double Hydroxides

Resumo

The MgAl layered double hydroxides (LDHs) were prepared by two-stage synthesis, which included mechanochemical activation at the first stage and the interaction of the resulting sample with distilled water at the second stage. The influence of the material of grinding bodies (steel and ceramics), the conditions of activation (activation time and the centripetal acceleration of balls), and the nature of initial compounds on the phase composition of the resulting products was investigated. It was established that the formation of a single-phase MgAl LDH was observed upon mechanochemical activation with the use of steel grinding bodies at an acceleration of 1000 m/s² for 30 min. The samples prepared by a traditional coprecipitation method and a method that included a stage of mechanochemical activation possessed identical structural parameters. However, the mixed oxides formed upon the calcination of LDHs synthesized by mechanochemical activation were characterized by a more uniform pore space with a pore diameter of 4–5 nm with a developed specific surface.