Intercalation of Salts of Fatty Acids Into Kaolinite

P. Sidheswaran, A. N. Bhat and P. Ganguli
Hindustan Lever Research Centre, Andheri (East), Bombay 400 099, India

Abstract: Intercalation of sodium and potassium salts of lauric, myristic, palmitic, elaidic, oleic, 12-hydroxystearic, and a blend of C8–C10 acids in kaolinite has been followed by X-ray powder diffraction, nuclear magnetic resonance (NMR), Fourier-transform infrared spectroscopy, and thermal studies. The 7-Å ‘c’ axis spacing in kaolinite expands to 11 Å as a result of intercalation; this expansion is independent of the alkyl chain length of the fatty acid. The orientation of the organic molecules in the kaolinite interlayer is nearly flat, and 1H NMR indicates an enhanced ordering in the potassium laurate intercalate. The reversal or equalization of the relative intensities of hydroxyl bands at 3696 and 3619 cm-1 of kaolinite are related to the phenomenon of intercalation. The decomposition temperature of these salts decreases when they are intercalated in kaolinite.

Key Words: Fatty acid • Fourier-transform infrared spectroscopy • Intercalate • Kaolinite • Nuclear magnetic resonance • Orientation • X-ray powder diffraction

Clays and Clay Minerals; February 1990 v. 38; no. 1; p. 29-32; DOI: 10.1346/CCMN.1990.0380104
© 1990, The Clay Minerals Society
Clay Minerals Society (www.clays.org)