Particle-Stabilized Emulsions: Effect of Heavy Crude Oil Components Pre-Adsorbed onto Stabilizing Solids.

Hannisdal A., Ese M.H. and Sjöblom J.

Ugelstad Laboratory, Department of Chemical Engineering,

Norwegian University of Science and Technology (NTNU), Norway.

Model emulsions stabilized by means of silica nanoparticles have been investigated. The effect of the modification of the particle surface has been monitored using infrared spectroscopy, contact angle measurements and zeta potential measurements. It is shown that coating of the nanoparticles with asphaltenes and resins will modify the stabilization profile compared to that obtained with no coating. Asphaltene-coated particles lead to a substantial increase in emulsion stability, while coating with resins only results in minor changes. Possible stabilization mechanisms have been discussed. We have observed very elastic water-oil-interfaces due to adsorbed particles. It has been shown that the inversion of o/w emulsions into w/o emulsions can be achieved by modifying the hydrophilicity of the silica particles or by a controlled coating with heavy components from the crude oil. The relevance of this study for real petroleum systems is discussed.