The Influence of a Hydrothermal Treatment using Microwave Heating on the Crystallinity of Layered Double Hydroxides

Differently synthesised layered double hydroxides (LDH) were characterised by using XRD, N2 adsorption, DTA/TG and 27Al NMR. The results of these investigations are discussed with respect to the crystallinity and purity of the material in dependence on the preparation method (without aging, aging at 20 °C, aging under hydrothermal conditions using microwave heating). It is shown that microwave heating is a suitable method to prepare well crystallised LDH without impurities in the form of e.g. Mg(OH)2 and Al(OH)3 and with a sufficient specific surface area within acceptable times.