MRI profiles over very wide concentration ranges: Application to swelling of a bentonite clay
2009 (English)In: Journal of magnetic resonance (San Diego, Calif. 1997: Print), ISSN 1090-7807, E-ISSN 1096-0856, Vol. 198, no 2, 146-150 p.Article in journal (Refereed) Published
In MRI investigation of soils, clays, and rocks, mainly mobile water is detected, similarly to that in biological and medical samples. However, the spin relaxation properties of water in these materials and/or low water concentration may make it difficult to use standard MRI approaches. Despite these limitations, one can combine MRI techniques developed for solid and liquid states and use independent information on relaxation properties of water, interacting with the material of interest, to obtain true images of both water and material content. We present procedures for obtaining such true density maps and demonstrate their use for studying the swelling of bentonite clay by water. A constant time imaging protocol provides 1D mapping of the clay distribution in regions with clay concentration above 10 vol%. T-1 relaxation time imaging is employed to monitor the clay content down to 10(-3) vol%. Data provided by those two approaches are in good agreement in the overlapping range of concentrations. Covering five orders of magnitude of clay concentration, swelling of sodium-exchanged bentonite clays from pre-compacted pellets into a gel phase is followed in detail.
Place, publisher, year, edition, pages
2009. Vol. 198, no 2, 146-150 p.
IdentifiersURN: urn:nbn:se:kth:diva-18453DOI: 10.1016/j.jmr.2009.01.035ISI: 000266387200002ScopusID: 2-s2.0-67349147510OAI: oai:DiVA.org:kth-18453DiVA: diva2:336500
QC 201005252010-08-052010-08-052010-12-20Bibliographically approved