Organo-smectite complexes

Yariv and Lapides [104] demonstrated the utility of thermo-XRD analysis in the study of organo-smectite complexes, such as montmorillonite complexes with anilines, fatty acids, alizarinate, and protonated Congo red, and of complexes of other smectites with acridine orange. The technique is very efficient in determining whether the adsorbed organic species penetrates into the... 

V. Vertisols Description dark soils with swelling clays (smectite) and highly stables organo-mineral complexes formed under warm and dry climates. ... 

The only detailed information available on the structures of organo-clays is from studies of vermiculite and kaolinite complexes. Unfortunately, smectites do not form three-dimensionally ordered structures. For the organo-smectites, it is possible to roughly determine the orientation of the molecules in the interlayer space based on the dimensions of the molecules, assumptions as to how the molecules are attached to the clay smface and measured increases in the interlayer spacing compared to the untreated clay mineral. In certain c lses it is possible to calculate the X-ray diffraction intensities for model structrues and compare these with measured values. For example, Reynolds (1965) showed that the ethylene glycol molecule is oriented with the symmetry plane of the molecule oriented normal to the clay layer and coordinating the interlayer Ca ions in a structure with only one-dimensional... 

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