Hierarchical synchrotron diffraction and imaging study of the calcium sulfate hemihydrate–gypsum transformation
The mechanism of hydration of calcium sulfate hemihydrate (CaSO·0.5HO) to form gypsum (CaSO·2HO) was studied by combining scanning 3D X-ray diffraction (s3DXRD) and phase contrast tomography (PCT) to determine in situ the spatial and crystallographic relationship between these two phases. From s3DXR...
| Autores: | , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2023 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/352738 |
| Acceso en línea: | http://hdl.handle.net/10261/352738 |
| Access Level: | acceso abierto |
| Palabra clave: | Scanning 3D X-ray diffraction s3DXRD Phase contrast tomography Gypsum hemihydrate Calcium sulfate Crystal orientation Hydration Image reconstruction Precipitation (chemical) Tomography X ray diffraction |
| Sumario: | The mechanism of hydration of calcium sulfate hemihydrate (CaSO·0.5HO) to form gypsum (CaSO·2HO) was studied by combining scanning 3D X-ray diffraction (s3DXRD) and phase contrast tomography (PCT) to determine in situ the spatial and crystallographic relationship between these two phases. From s3DXRD measurements, the crystallographic structure, orientation and position of the crystalline grains in the sample during the hydration reaction were obtained, while the PCT reconstructions allowed visualization of the 3D shapes of the crystals during the reaction. This multi-scale study unfolds structural and morphological evidence of the dissolution–precipitation process of the gypsum plaster system, providing insights into the reactivity of specific crystallographic facets of the hemihydrate. In this work, epitaxial growth of gypsum crystals on the hemihydrate grains was not observed. |
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