Magnetic orientation of nontronite clay in aqueous dispersions and its effect on water diffusion
2015 (English)In: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 437, 205-210 p.Article in journal (Refereed) Published
The diffusion rate of water in dilute clay dispersions depends on particle concentration, size, shape, aggregation and water-particle interactions. As nontronite clay particles magnetically align parallel to the magnetic field, directional self-diffusion anisotropy can be created within such dispersion. Here we study water diffusion in exfoliated nontronite clay dispersions by diffusion NMR and time-dependant 1H-NMR-imaging profiles. The dispersion clay concentration was varied between 0.3 and 0.7 vol%. After magnetic alignment of the clay particles in these dispersions a maximum difference of 20% was measured between the parallel and perpendicular self-diffusion coefficients in the dispersion with 0.7 vol% clay. A method was developed to measure water diffusion within the dispersion in the absence of a magnetic field (random clay orientation) as this is not possible with standard diffusion NMR. However, no significant difference in self-diffusion coefficient between random and aligned dispersions could be observed.
Place, publisher, year, edition, pages
2015. Vol. 437, 205-210 p.
Nontronite clay, Magnetic alignment, Exfoliated clay, Anisotropic microstructure, Diffusion, Permeability, Bound water, NMR 1D imaging, Diffusion NMR
IdentifiersURN: urn:nbn:se:kth:diva-158797DOI: 10.1016/j.jcis.2014.09.031ISI: 000345109000027ScopusID: 2-s2.0-84908331427OAI: oai:DiVA.org:kth-158797DiVA: diva2:787888
QC 201502122015-02-122015-01-122015-02-12Bibliographically approved