Investigation of foam and emulsion destruction under the great pressure gradients

Abstract

The effect of high pressure gradients with the help of the membrane under which a decreased pressure is created and centrifugal forces on a decrease of the content of the dispersion medium in the emulsion and foam and increase in the capillary pressure was studied. In a centrifugal field at low angular velocity of rotation (ω=52.3 s−1) the equilibrium capillary pressure is established in the emulsion and foam. At higher angular velocity the emulsion and foam were collapsed as a certain pressure is reached in Plateau borders of the emulsion and foam; this pressure was smaller than the pressure balancing the forces of the centrifugal field. The capillary pressure in the highly dispersed emulsion reached pressure drop applied to the membrane (Pσ=PT=70 kPa). Emulsions from sodium dodecylsulfate and 9-10 oxyethylated alkylphenol (OP-7) with 0.1 and 0.4 mol/dm3 NaCl adding prepared by shaking with hexane and dodecane destructed at some capillary pressure which were less than the pressure drop supplied to the porous membrane.