The adsorption of methanol-benzene and ethanol-cyclohexane mixtures has been studied on hydrophobic layer silicates made hydrophobic by cationic surfactants (C12-C18). X-ray diffraction measurements of these expanded systems gave the interlayer spacing and interlayer volumes. From the adsorption measurements and from the interlayer volumes the composition of the interlayer phases was determined. It was established that for a known concentration range of surfactant-alcohol-benzene (or cyclohexane) composition the adsorption layer had a smectic or nematic structure in the interlayer space. This layer can be produced without silicate lamellae for a specific concentration range with a small amount of water. A liquid-crystalline structure was shown to be present from polarization microscopy and small-angle X-ray diffraction measurements. At higher alcohol concentrations the adsorption layer was thinner and the lyotropic liquid-crystalline phase no longer existed. The well oriented adsorption layer broke down and the interlayer spacing became smaller.
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