Transactions of the INDIAN CERAMIC SOCIETY Vol. 26 1967
The Role of Monovalent and Divalent Cations in the
Dehydroxylation of Kaolinite
P. PRABHAKARAM
Pages : 57-64
DOI : 10.1080/0371750X.1967.10855586
Abstract
Homoionic forms of kaolinite exhibit differences in peak shapes of dehydroxylation
reaction in differential thermal analysis. In general, H-forms and Na-forms gave
higher amplitudes, AJW and slope ratios than the divalent cations.
The differences in the dehydroxylation peaks of homoionic forms were due to
changes in the rate of dehydroxylation. The divalent cations generally decreased the
rate of dehydroxylation, probably due to the formation of oxide linkages which brought
down the interparticle porosity and obstructed easy escape of water vapour. Slight
pressure due to entrapped water vapour caused retardation of the forward reaction.
