| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 593410 | Colloids and Surfaces A: Physicochemical and Engineering Aspects | 2013 | 12 Pages |
•Rheo-SAXS experiments are applied on organoclays water in oil emulsion under shear flow.•Stable emulsions exhibit a shear-thinning behavior with a shear stress.•The nature and the concentration in OC influence the viscosity under flow.•Under shear flow, the structure and isotropic distribution of OC particles are maintained.
Organoclay (OC) loaded macroemulsions are systems used worldwide as drilling-fluid in oil extraction. SAXS and viscosity measurements (Rheo-SAXS) are simultaneously performed on OC loaded water in dodecane emulsions (W/D = 10/90), at different shear rates in the range 0.1–1000 s−1. The role of three OC (VG69, Bentone and Geltone) was investigated at different concentrations (<3.5%, m/m). The stabilization of W/D emulsions implies co-addition of OC > 2% (m/m) and surfactants. These emulsions exhibit a shear thinning behavior with a yield stress. The dispersion state of the clay mineral particles inferred, with a fit of SAXS profiles using a scattering model of stacking of N core-layer platelets. The structure of clay mineral particles is unchanged under flow and clay mineral particles are isotropically dispersed under a shear rate <1000 s−1. Bentone with the best ability to swell in dodecane, has the large impact on viscosity.
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