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Magnetorheological behavior of Pickering emulsions stabilized by surface-modified Fe3O4 nanoparticles
- Source :
-
Colloids & Surfaces A: Physicochemical & Engineering Aspects . Oct2012, Vol. 412, p20-28. 9p. - Publication Year :
- 2012
-
Abstract
- Abstract: Silane-modified Fe3O4 nanoparticles can stabilize emulsions of both polar and non-polar oils, and the rheological behavior of these emulsions has been investigated as a function of oil volume fraction (ϕ o), oil polarity and magnetic field intensity (ψ). All the emulsions show a similar elastic response with a modulus plateau at low frequency and a small phase angle (<15°) in dynamic oscillatory shear, and shear-thinning behavior in steady shear measurements. This is independent of ϕ o, oil polarity and ψ. The dynamic modulus (G′) and complex viscosity (η*) increase with an increase in ϕ o and oil polarity, due to enhanced droplet packing and flocculation and particle aggregation on droplet surfaces. The presence of a magnetic field promotes particle attractions and associations and enhances the strength of the three-dimensional particle and droplet networks, thus remarkably increasing G′ and η* and raising the yield stress. The increase in modulus, viscosity and yield stress are beneficial for the elevation of the stability of these functional emulsions. [Copyright &y& Elsevier]
Details
- Language :
- English
- ISSN :
- 09277757
- Volume :
- 412
- Database :
- Academic Search Index
- Journal :
- Colloids & Surfaces A: Physicochemical & Engineering Aspects
- Publication Type :
- Academic Journal
- Accession number :
- 79872298
- Full Text :
- https://doi.org/10.1016/j.colsurfa.2012.06.026