Muiambo, H.F. (Herminio Francisco)Focke, Walter Wilhelm2012-04-162013-02-282012-02Muiambo, HF & Focke, WW 2012, 'Ion exchanged vermiculites with lower expansion onset temperatures', Molecular Crystals and Liquid Crystals, vol. 555 no. 1, pp. 65–75.1542-1406 (print)1563-5287 (online)10.1080/15421406.2012.634367http://hdl.handle.net/2263/18592South African Palabora vermiculite was modified by ion exchange with ammonium and selected alkali metal and alkaline earth metal ions. In the exchanged vermiculite with ammonium ions, it was found that ammonia and water were the blowing agents and they were simultaneously released during thermal degradation. In the increasing ionic potential series: Na, Ba, Ca and Mg, it was found that the onset expansion temperature also increased dramatically. Exchange with relatively low ionic potential species, namely sodium, potassium and ammonium, lowered the exfoliation onset temperature of vermiculite to below 300◦C.en© Taylor & Francis. This is an electronic version of an article published in Molecular Crystals and Liquid Crystals, Vol. 555: pp. 65–75, 2012. Molecular Crystals and Liquid Crystals is available online at: http://www.tandfonline.com/loi/gmcl20.VermiculiteIon exchangeExfoliationInterstratificationThermal analysisPostprint Article