A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Nature of disorder in synthetic hectorite
Abstract The disorder of synthetic Na-hectorite was investigated using structural simulation of X-ray powder patterns. The method used to characterize this clay mineral was based on the comparison between experimental and calculated X-ray diffraction profiles. The study was achieved in two steps: (i) the quantitative interpretation of 00l reflections enabled the determination of the number of intercalated water molecules, their positions and the stacking mode of the clay mineral layers along the normal to the (a, b) plane; and (ii) the study of the hkl reflections with h and/or k ≠0 enabled the characterization of the structural evolution in the (a, b) plane of synthetic hectorite. Many models of disorder with random shifts of ± a/3, a/3+ b/3, 80% of a/3+ b/3 and 20% of a/3 with a total density of defects of 80%, gave the best fit to the observed data at the level of (02, 11), (20, 13), (04, 22), (15, 24, 31) and (06, 33) bands with 5° of tetrahedral cavity distortion (the rotation angle of the tetrahedra).
Research Highlights ► This study was focused on structural properties of synthetic hectorite using simulation of the XRD patterns. ► The Simulation was based on comparison between experimental and theoretical XRD patterns. ► Many models of disorder with random shifts gave the best fit for all bands.
Nature of disorder in synthetic hectorite
Abstract The disorder of synthetic Na-hectorite was investigated using structural simulation of X-ray powder patterns. The method used to characterize this clay mineral was based on the comparison between experimental and calculated X-ray diffraction profiles. The study was achieved in two steps: (i) the quantitative interpretation of 00l reflections enabled the determination of the number of intercalated water molecules, their positions and the stacking mode of the clay mineral layers along the normal to the (a, b) plane; and (ii) the study of the hkl reflections with h and/or k ≠0 enabled the characterization of the structural evolution in the (a, b) plane of synthetic hectorite. Many models of disorder with random shifts of ± a/3, a/3+ b/3, 80% of a/3+ b/3 and 20% of a/3 with a total density of defects of 80%, gave the best fit to the observed data at the level of (02, 11), (20, 13), (04, 22), (15, 24, 31) and (06, 33) bands with 5° of tetrahedral cavity distortion (the rotation angle of the tetrahedra).
Research Highlights ► This study was focused on structural properties of synthetic hectorite using simulation of the XRD patterns. ► The Simulation was based on comparison between experimental and theoretical XRD patterns. ► Many models of disorder with random shifts gave the best fit for all bands.
Nature of disorder in synthetic hectorite
Karmous, Mohamed Salah (author) / Samira, Jemai (author) / Robert, Jean-Louis (author) / Amara, Abdesselem Ben Haj (author)
Applied Clay Science ; 51 ; 23-32
2010-10-20
10 pages
Article (Journal)
Electronic Resource
English
Hectorite , Defects , XRD , Translations , Rotation