Spectroscopic studies of kaolinite surfaces

Sammanfattning: In this thesis, specific surface reactions on kaolinite have been investigated. The methods used are diffuse reflectance Fourier transform (DRIFT), FT-Raman and micro Raman spectroscopy. The deuterium exchange of the hydroxyl protons of kaolinite has been studied. Results show that long reaction time and increased temperature are needed for the deuteration to occur. A change in pH does not seem to influence the isotopic exchange. The adsorption of three silane coupling agents, starch and dextrin onto the kaolinite surface has been investigated. It is suggested that the adsorption occurs through hydrogen bonding. Studies of the hydroxyl vibrations of kaolinite in near-IR, mid-IR and Raman spectra were performed. Raman spectra were recorded at 298K and at 77K. Difference, combination and summation bands appear in near- and mid-IR spectra. Shifts of the hydroxyl bands, are observed in Raman spectra when kaolinite is cooled to 77K.