Abstract
The thermal behavior of halloysite–dimethylsulfoxide (DMSO) intercalation complex was investigated by thermogravimetry–derivative thermogravimetry and differential scanning calorimetry (TG–DTG–DSC) analysis, X-ray diffraction (XRD) analysis, and Fourier transform infrared (FT-IR) spectroscopic analysis. The samples gradually heated up to different temperatures were studied by XRD and FT-IR. The TG–DTG results indicated that the mass losses of the intercalation complex contained two main stages, which correspond to (a) desorption of the DMSO molecules and (b) dehydroxylation of halloysite. The kaolinite–dimethylsulfoxide intercalation complex is stable below 150 °C. The XRD data indicated that the relative intensity of the peak with value of 1.12 nm decreased as increasing the temperature and disappeared at 200 °C; however, the peak with the value of 0.734 nm gradually increased in the XRD patterns. In the FT-IR spectra, the appearance of methyl bands at 3022 and 2934 cm−1 and the change of intensities for inner surface hydroxyl indicated the presence of intercalated dimethylsulfoxide. With the rise in the temperature, the intensities of methyl bands at 3022 and 2934 cm−1 decreased and remained until around 150 °C; however, the intensities of the bands attributed to inner surface hydroxyl gradually increased, which agree with the XRD and TG–DTG–DSC data.