Effect of microware radiation on the crystallinity of layered materials

The results obtained in the preparation of hydrotalcite-like compounds using microwave radiation are reported. The following systems were synthesized: Mg,Al-CO3, Mg,Cr-CO3, Ni,Al-CO3 y Zn,Ni,Al-CO3. The results obtained by the microwave-hydrotermal method have been compared with the conventional-hydrotermal one. A working protocol, which allows us to obtain reproducible results, has been elaborated, and this is a new aspect in the synthesis of inorganic solids. The obtained solids were characterized by several techniques (X ray difracttion, thermal analysis, chemical analysis and N-2 adsorption-desorption at -196 degreesC). Hydrotalcite-like compounds with the desirable chemical composition were obtained. The cristallinity depends on the microwave, radiation exposure time in all cases. Materials prepared using microwave radiation exhibit a better grain size homogeneity and a good crystalline degree and it also influences over the water molecules arrangement in the solid.