Magnetic orientation of nontronite clay in aqueous dispersions and its effect on water diffusion
Journal article, 2015

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.

Diffusion NMR

Anisotropic microstructure

Magnetic alignment

NMR 1D imaging

Permeability

Diffusion

Bound water

Nontronite clay

Exfoliated clay

Author

Christoffer Abrahamsson

SuMo Biomaterials

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry

Lars Nordstierna

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry

Matias Nordin

German Cancer Research Center (DKFZ)

S. V. Dvinskikh

Royal Institute of Technology (KTH)

Saint Petersburg State University - Spsu

Magnus Nydén

University of South Australia

Journal of Colloid and Interface Science

0021-9797 (ISSN) 1095-7103 (eISSN)

Vol. 437 205-210

Subject Categories

Physical Chemistry

DOI

10.1016/j.jcis.2014.09.031

More information

Latest update

8/18/2020