Spectra of kaolinite hydroxyls in dimethylsulphoxide-intercalated kaolinites at 77 K

The kaolinites from Kiralyhegy and Szeg in Hungary, examples of a low- and high-defect kaolinite were intercalated by mixing 300 mg of the kaolinite in 5 cm3 of anhydrous DMSO at 25°C using a magnetic stirrer for 80 h.  Raman spectra were measured using a Renishaw Raman microprobe. Experimental details have been published previously (Frost R.L., Tran T.H. & Kristof, J. (1997) Intercalation of an ordered kaolinite — a Raman microscopy study. Clay Miner. 32, 587–59 & Johansson U., Frost R.L., Forsling W. & Kloprogge J.T. (1998) Raman spectroscopy of the kaolinite hydroxyls at 77 K. Appl. Spectrosc. 52, 1277–1282.)

Figure 1 is Raman spectra in the OH- stretching region of DMSO- intercalcated (a) high-defect kaolinite at 298 K, (b) low-defect kaolinite at 298 K, (c) high-defect kaolinite at 77 K and (d) low-defect kaolinite at 77 K.  Figure 2 is the Raman spectrum of the OH-stretching region of low-defect kaolinite at 77 and 298 K.  Figure 3 shows a band component analysis of the Raman spectrum in the OH-stretching region of DMSO-intercalated low-defect kaolinite at 298 K.  Figure 4 is Band component analysis of the Raman spectrum in the OH-stretching region of DMSO-intercalated, low-defect kaolinite at 77 K.  Figure 5 shows band component analysis of the Raman spectrum in the OH-stretching region of DMSO-intercalated, high-defect kaolinite at 298 K.