• Size determinations of crystallites and hydrophilic/hydrophobic domains in polycrystalline lamellar soaps by x-ray diffraction

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    • Keywords


      Crystallite size; x-ray diffraction; x-ray line broadening; soap structure

    • Abstract


      An experimental approach based on x-ray diffraction is presented for the size determinations of crystallites and of hydrophilic/hydrophobic domains in polycrystalline, lamellar soaps. Literature review indicates that the mean shape of a soap crystallite is definable only along its c-axis, while no conclusions can be drawn concerning its shape along thea andb-axes. Nevertheless, it is shown that it is possible to determine the volume average crystallite dimensions and those of hydrophilic/hydrophobic domains contained in them, from a knowledge of polycrystalline soap’s short and longd-spacings, line widths at half maximum intensity of 001 andhk.0 plane reflections, the densities of hydrocarbon and the water layers, the molecular weight and the total fatty matter content of soap. The methods are illustrated using x-ray diffraction data obtained on-commercial stearic, lauric, oleic, elaidic, 12-hydroxystearic and 12-ketostearic soaps of practical interest to soap industry.

    • Author Affiliations


      M K Nagarajan1

      1. Hindustan Lever Research Centre, Bombay - 400 093
    • Dates

  • Journal of Chemical Sciences | News

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