Hierarchical synchrotron diffraction and imaging study of the calcium sulfate hemihydrate–gypsum transformation
Metadata
Show full item recordEditorial
Int Union Crystallography
Materia
Scanning 3D X-ray diffraction s3DXRD Phase contrast tomography Gypsum hemihydrate
Date
2023-06Referencia bibliográfica
La Bella, M., Besselink, R., Wright, J. P., Van Driessche, A. E., Fernandez-Martinez, A., & Giacobbe, C. (2023). Hierarchical synchrotron diffraction and imaging study of the calcium sulfate hemihydrate–gypsum transformation. Journal of Applied Crystallography, 56(3).[https://doi.org/10.1107/S1600576723002881]
Abstract
The mechanism of hydration of calcium sulfate hemihydrate (CaSO4 0.5H2O) to
form gypsum (CaSO4 2H2O) 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.