Kinetics of deintercalation of potassium acetate from kaolinite - a Raman spectroscopic study

The kinetics of structural change of a highly ordered kaolinite intercalate d with potassium acetate have been studied through both intercalation and d eintercalation. Deintercalation of the intercalated kaolinite, brought abou t by washing for different time intervals was followed by both X-ray diffra ction and Raman microscopy. X-ray diffraction shows the kaolinite to be hig hly ordered with a Hinckley index of 1.42 and intercalated to similar to 90 %. X-ray diffraction also showed that the intercalated kaolinite was deinte rcalated by 80% in the first minute of washing. An additional Raman band, a ttributed to the inner surface hydroxyl groups, strongly hydrogen bound to the acetate, is observed at 3605 cm(-1) for the potassium acetate intercala te with the concomitant loss of intensity in the bands at 3652, 3670, 3684 and 3693 cm(-1). Upon deintercalation, the intensity of the 3605 cm-l band decreased as the 3695 cm(-1) band increased. The Raman spectral changes bro ught about upon deintercalation mirrored the changes observed by X-ray diff raction. Deintercalation of kaolinite caused disordering of the kaolinite.