The thermal decomposition of halloysite-potassium acetate intercalation compound was investigated by thermogravimetric analysis and infrared emission spectroscopy The X-ray diffraction patterns indicated that intercalation of potassium acetate into halloysite caused an increase of the basal spacing from 1 00 to 1 41 nm The thermogravnnetry results show that the mass losses of intercalation the compound occur in main three main steps which correspond to (a) the loss of adsorbed water (b) the loss of coordination water and (c) the loss of potassium acetate and dehydroxylation The temperature of dehydroxylation and dehydration of halloysite is decreased about 100 degrees C The infrared emission spectra clearly show the decomposition and dehydroxylation of the halloysite intercalation compound when the temperature is raised The dehydration of the intercalation compound is followed by the loss of intensity of the stretching vibration bands at region 3600-3200 cm(-1) Dehydroxylation is followed by the decrease in intensity in the bands between 3695 and 3620 cm(-1) Dehydration was completed by 300 degrees C and partial dehydroxylation by 350 degrees C The inner hydroxyl group remained until around 500 degrees C (C) 2010 Elsevier B V All rights reserved