MIGRATION AND CRYSTALLIZATION OF INTERLAMELLAR WATER DURING FREEZING AND THAWING OF WYOMING BENTONITE.
Homo-ionic, clay-water pastes of Wyoming bentonite were studied at near freezing temperatures by X-ray diffraction. On freezing, the initial high d(001) spacings of the lithium- and sodium-bentonite pastes decreased, first to about 19A and, at about -10C, to 16A. When the temperature was raised the...
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| Format: | Text |
| Language: | English |
| Published: |
1965
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| Online Access: | http://www.dtic.mil/docs/citations/AD0631150 http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=AD0631150 |
| Summary: | Homo-ionic, clay-water pastes of Wyoming bentonite were studied at near freezing temperatures by X-ray diffraction. On freezing, the initial high d(001) spacings of the lithium- and sodium-bentonite pastes decreased, first to about 19A and, at about -10C, to 16A. When the temperature was raised the d(001) spacings of the frozen clays increased substantially; on melting, he d(001) spacings quickly expanded to their initial high values. The behavior of the hydrogen-aluminum-, potassium-, and calcium-bentonite was similar except that spacings greater than about 20A did not occur. Evidently, when bentonite-water pastes are frozen, all but two or three monomolecular layers of the interlamellar water migrate into the pore space to form ordinary ice. The remaining interlamellar water therefore must correspond to the 'unifrozen' water of previous investigations. Only the diffraction peaks corresponding to the normal hexagonal ice structure were detected. The relative intensities of the diffraction peaks revealed evidence of epitaxy in that the ice crystals appeared to be preferentially oreinted with their c-axes perpendicular to the c-axes of the clay crystals. (Author) |
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