Kinetic study of the intercalation process of dimethylsulfoxide in kaolinite

Abstract

A kinetic study of the intercalation reaction of dimethylsulfoxide (DMSO) into the layers of kaolinite was carried out. Several kaolinite–DMSO mixtures were analyzed at four temperatures (60, 50, 45 and 40 °C). Structural characterization was done by X-ray diffraction (XRD). The intercalation reaction was followed by XRD of the kaolinite–DMSO intercalates at different reaction times and temperatures. A kinetic analysis of the process was performed considering a two-step simple mechanism for consecutive reactions: ingress of DMSO molecules into the kaolinite galleries and subsequent rotation of DMSO molecules. Finally, the activation energies of the two steps proposed for the global intercalation process were estimated.