| abstract |
A biliquid foam composition is prepared by agitating a hydrogen bonded liquid containing a soluble surfactant to produce a gas foam and intermittently adding to the gas foam a non-polar liquid which is immiscible with the hydrogen bonded liquid, the surfactant-containing hydrogen bonded liquid and non-polar liquid being selected to provide a spreading coefficient equal to or greater than zero. The resulting mixture is agitated after each addition so as to cause the non-polar liquid to initially spread on the foam surfaces and thereafter form non-coalescing globules of non-polar liquid dispersed in a continuous phase of the hydrogen bonded liquid and each encapsulated in a double surfaced surfactant-stabilized film of the hydrogen bonded liquid containing the soluble surfactant. The quantity of non-polar liquid added at each addition is such that the hydrogen bonded liquid remains the environment of any encapsulated globules of non-polar liquid formed, the total phase volume ratio (PVR) of the non-polar liquid to the hydrogen bonded liquid being up to about 50. The biliquid foams prepared in accordance with the invention have several noteworthy applications. For example, biliquid foams made of hydrocarbons and water are exceptionally good cleaning agents since they comprise both a finely dispersed hydrocarbon which can remove greases and water combined with detergent which can remove water soluble soils. |