Rheology of concentrated perfluorocarbon emulsions.

Abstract

Oil-in-water emulsions conthing perfluomtylbromide (perflubron; PFOB) at up to about 50 vol.% and stabilized with egg yolk pbospbolipid (EYP) have been prepared and their rheology bas been studied. The emulsions are non-Newtonian, and their viscosities are strongly dependent on the volume fnction of pertlubron. as well as on pmcessing and formulation. Using a controlled-stress rbeometer with double-gap geometry, the viscosity at shear rates less hn 0. I sec-1 an be measured. Tbe viscoelastic properties of the emulsions have been explored using oscilhtion and stress-sweep techniques and an be used for the prediction of emulsion stability. MatPrbls and Metbods Pertluhn and naturnl egg yolk phospholipid were used as purchased without further purification. Bohlin CS (controlled-suess) rheMneter with C25 (concentric cylinder, 12ml sample) or DG (double gap, 30 ml sample) meauring geometry was used for dynamic (stress-sweep and oscillation) and smtic (viscosity, etc.) measurements. BrooWield dplate viscometer (Iml sample) was also used for routine viscosity measurements. Results and Discussion