| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 9675712 | Colloids and Surfaces A: Physicochemical and Engineering Aspects | 2005 | 7 Pages |
Abstract
The time evolution of the optical absorbance of the suspensions as a function of oleic acid (OA) concentration, silica nanoparticles concentration and magnetic field strength and direction has been analyzed. Adsorption isotherm demonstrated that OA adsorbs onto iron particles. However, only after the addition of very large amounts of OA (i.e. much more than the amount needed to form a monolayer coating) it is possible to design stable suspensions. The application of an external magnetic field provokes a faster sedimentation due to the formation of field-induced aggregates. When silica nanoparticles are used as stabilizer, a threshold value has been found in the silica concentration. Above this value iron suspensions are stable. The application of a magnetic field decreases this threshold concentration value due to the combined effect of the induced iron chains aggregation and the silica gel network.
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Colloid and Surface Chemistry
Authors
M.T. López-López, J. de Vicente, F. González-Caballero, J.D.G. Durán,