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Non-aqueous foams in lubricating oil systems

Binks, B.P.; Davies, C.A.; Fletcher, P.D.I.; Sharp, E.L.


C.A. Davies

P.D.I. Fletcher

E.L. Sharp


We have investigated the foaming properties of mixtures of a hydrocarbon oil solvent with various low molar mass, polymeric and overbased detergent particle additives used in lubricating oils. Foam formation occurs only when the additive concentration and temperature are such that the single-phase mixtures are close to a phase separation boundary when solvent affinity for the solute is low. This is likely to maximise the tendency of the solute to adsorb at the liquid-air surface and thereby promote foam formation. Multi-phase mixtures either maintain or suppress the foamability of the single-phase mixtures. The foams formed contain spherical, polydisperse gas bubbles and liquid volume fractions greater than about 20 vol.% indicating they are " wet" , transient foams in which the adsorbed solute films at the liquid-air surface can affect liquid drainage but are incapable of resisting coalescence between contacting bubbles. Consistent with this model, the foam half-life is found to scale with the kinematic viscosity of the liquid. © 2010 Elsevier B.V.


Binks, B., Davies, C., Fletcher, P., & Sharp, E. (2010). Non-aqueous foams in lubricating oil systems. Colloids and surfaces. A, Physicochemical and engineering aspects, 360(1-3), 198-204.

Journal Article Type Article
Acceptance Date Feb 24, 2010
Online Publication Date Mar 3, 2010
Publication Date May 5, 2010
Journal Colloids and Surfaces A: Physicochemical and Engineering Aspects
Print ISSN 0927-7757
Publisher Elsevier
Peer Reviewed Peer Reviewed
Volume 360
Issue 1-3
Pages 198-204
Keywords Colloid and Surface Chemistry
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