Magnetically induced structural anisotropy in binary colloidal gels and its effect on diffusion and pressure driven permeability
Journal article, 2014

We report on the synthesis, microstructure and mass transport properties of a colloidal hydrogel selfassembled from a mixture of colloidal silica and nontronite clay plates at different particle concentrations. The gel-structure had uniaxial long-range anisotropy caused by alignment of the clay particles in a strong external magnetic field. After gelation the colloidal silica covered the clay particle network, fixing the orientation of the clay plates. Comparing gels with a clay concentration between 0 and 0.7 vol%, the magnetically oriented gels had a maximum water permeability and self-diffusion coefficient at 0.3 and 0.7 vol% clay, respectively. Hence the specific clay concentration resulting in the highest liquid flux was pressure dependent. This study gives new insight into the effect of anisotropy, particle concentration and bound water on mass transport properties in nano/microporous materials. Such findings merit consideration when designing porous composite materials for use in for example fuel cell, chromatography and membrane technology.

diffusion

permeability

magnetic field

clays

anisotropy

gels

flow

silica

Author

Christoffer Abrahamsson

SuMo Biomaterials

Chalmers, Chemical and Biological Engineering, Applied Surface Chemistry

Lars Nordstierna

Chalmers, Chemical and Biological Engineering, Applied Surface Chemistry

Johan Bergenholtz

University of Gothenburg

Annika Altskär

SIK – the Swedish Institute for Food and Biotechnology

Magnus Nydén

University of South Australia

Soft Matter

1744-683X (ISSN) 1744-6848 (eISSN)

Vol. 10 24 4403-4412

Subject Categories

Physical Chemistry

Materials Chemistry

DOI

10.1039/C4SM00315B

More information

Latest update

8/24/2018