Studies on the thermal behavior and decomposition mechanism of dickite-potassium acetate complexes

The thermal decomposition and de-hydroxylation process of dickite-potassium acetate (KAc) intercalated complex was studied using thermogravimetric (TG), differential thermal analysis (DTA), XRD and FTIR. The stability of intercalated complex was affected by heat treatment directly. The TG-DTA results showed that four changes had occurred at 64.5, 118, 301 and 406 A degrees C, which can be attributed to (a) the loss of adsorbed water, (b) loss of the water linked to acetate ion in the layer of dickite, (c) decomposition of KAc, and (d) loss of water through de-hydroxylation, respectively. The XRD and FTIR results showed that when the heating temperature exceeded 400 A degrees C, inner surface hydroxyls and inner hydroxyls lost gradually, generating amorphous meta-dickite. Further researches demonstrated that phase transition temperature of meta-dickite and mullite changed a lot through the intercalated KAc.