Why Does Halloysite Roll?—A New Model

Balbir Singh
Centre for Microscopy and Microanalysis, The University of Queensland Brisbane, Qld. 4072, Australia

Abstract: A model is presented to explain why tubular halloysite rolls in preference to tetrahedral rotation to correct misfit of the octahedral and tetrahedral sheets. It is shown that the rolling mechanism operates as it encounters significantly less resistance from Si-Si repulsion in comparison to tetrahedral rotation to correct the same amount of misfit. The model explains the observed and experimental rolling of planar kaolinites to form tubular halloysite upon hydration and exfoliation.

Key Words: Coulomb repulsion • Kaolinite • Rolling • Tetrahedral rotation • Tubular Halloysite

Clays and Clay Minerals; April 1996 v. 44; no. 2; p. 191-196; DOI: 10.1346/CCMN.1996.0440204
© 1996, The Clay Minerals Society
Clay Minerals Society (www.clays.org)