Characterization of new silicate/oxide lamellar nanocomposites by emanation thermal analysis

Emanation thermal analysis was applied for the characterization of LaCo(fsa)2en-montmorillonite nanocomposites [(fsa)2en = N,N′-bis(3-carboxysalicydene)ethylenediamine], and the results were compared to the data given by thermogravimetry and evolved gas analysis. The emanating rate of Na-montmorillonite increases up to 250°C with the elimination of the intercalated water, and then decreases progressively, however, with a shoulder at about 650°C when the layers are dehydroxylated. On the other hand, the emanating rate of LaCo(fsa)2en-montmorillonite increases up to 370°C, i.e., until the decomposition of the intercalated complex is achieved. Above 450°C, there is a rapid decrease of this rate, with only a slightly remarkable shoulder at about 650°C. The decrease of the emanating rate is characteristic for a decrease of surface area and porosity of the material, indicating that the thermal stability of LaCo(fsa)2en-montmorillonite is rather lower than that of Na-montmorillonite.