Resolving diffusion in clay minerals at different time scales: Combination of experimental and modeling approaches

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Details zur Publikation

Autor(en): Churakov SV, Gimmi T, Unruh T, Van Loon LR, Juranyi F
Zeitschrift: Applied Clay Science
Verlag: ELSEVIER SCIENCE BV
Jahr der Veröffentlichung: 2014
Band: 96
Seitenbereich: 36-44
ISSN: 0169-1317


Abstract


The size of the interlayer and the size of Mt particles are two characteristic dimensions which determine the time dependent behavior of water diffusion in Mt. MD simulations show that at very short time scales water dynamics has the characteristic features of an oscillatory motion in the cage formed by neighbors in the first coordination shell. At longer time scales, the interaction of water with the surface determines the water dynamics, and the effect of confinement on the overall water mobility within the interlayer becomes evident. At time scales corresponding to an average water displacement equivalent to the average size of Mt particles, the effects of tortuosity are observed in the meso- to macroscopic pore scale simulations. Consistent with the picture obtained in the simulations, the QENS data can be described using a (local) 3D diffusion at short observation times, whereas at sufficiently long observation times a 2D diffusive motion is clearly observed. The effects of tortuosity measured in macroscopic tracer diffusion experiments are in qualitative agreement with RW simulations. By using experimental data to calibrate molecular and mesoscopic theoretical models, a consistent description of water mobility in clay minerals from the molecular to the macroscopic scale can be achieved. In turn, simulations help in choosing optimal conditions for the experimental measurements and the data interpretation. (C) 2014 Elsevier B.V. All rights reserved.



FAU-Autoren / FAU-Herausgeber

Unruh, Tobias Prof. Dr.
Professur für Nanomaterialcharakterisierung (Streumethoden)


Zusätzliche Organisationseinheit(en)
Exzellenz-Cluster Engineering of Advanced Materials


Autor(en) der externen Einrichtung(en)
Paul Scherrer Institute (PSI)


Zitierweisen

APA:
Churakov, S.V., Gimmi, T., Unruh, T., Van Loon, L.R., & Juranyi, F. (2014). Resolving diffusion in clay minerals at different time scales: Combination of experimental and modeling approaches. Applied Clay Science, 96, 36-44. https://dx.doi.org/10.1016/j.clay.2014.04.030

MLA:
Churakov, Sergey V., et al. "Resolving diffusion in clay minerals at different time scales: Combination of experimental and modeling approaches." Applied Clay Science 96 (2014): 36-44.

BibTeX: 

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