Osmotic repulsion force due to adsorbed surfactants.

When considering interaction forces in surfactant-stabilized colloidal dispersions a factor that has been rarely discussed is the possible effect of osmotic force due to overlapping adsorbed surfactant monolayers. In the present work, the osmotic repulsion force is built-in on the basis of DLVO mechanics and based on Fischer's consideration of the analogous situation for adsorbed polymer layers on solid surfaces [E.W.

On the nature of Athabasca Oil Sands.

The existence of a thin aqueous film, separating bitumen (a form of heavy oil) from inorganic solids in Athabasca Oil Sands, is analysed based on "first principles". There is a general consensus in the literature on the hydrophilic character of the solids in oil sands. However, a review of the references cited in support of the solids being encapsulated in thin water envelopes produced a surprising lack of evidence.