Kaolinite: NMF Intercalates

Philippa J. R. Uwins1, Ian D. R. Mackinnon1, John G. Thompson2 and Anya J. E. Yago1
1 Centre for Microscopy and Microanalysis, The University of Queensland St. Lucia QLD 4072, Australia
2 Research School of Chemistry, Australian National University Canberra ACT 2601, Australia

Abstract: Bulk and size-fractionated kaolinites from seven localities in Australia as well as the Clay Minerals Society Source Clays Georgia KGa-1 and KGa-2 have been studied by X-ray diffraction (XRD), laser scattering, and electron microscopy in order to understand the variation of particle characteristics across a range of environments and to correlate specific particle characteristics with intercalation behavior. All kaolinites have been intercalated with N-methyl (NMF) after pretreatment with hydrazine hydrate, and the relative efficiency of intercalation has been determined using XRD. Intercalate yields of kaolinite: NMF are consistently low for bulk samples that have a high proportion of small-sized particles (i.e., <0.5 µm) and for biphased kaolinites with a high percentage (>60%) of low-defect phase. In general, particle size appears to be a more significant controlling factor than defect distribution in determining the relative yield of kaolinite: NMF intercalate.

Key Words: Defect distribution • Intercalates • Kaolinite • N-methyl formamide • Particle size

Clays and Clay Minerals; December 1993 v. 41; no. 6; p. 707-717; DOI: 10.1346/CCMN.1993.0410609
© 1993, The Clay Minerals Society
Clay Minerals Society (www.clays.org)