title: The role of dispersants' dynamic interfacial tension in effective crude oil spill dispersion.
abstract: The dispersion effectiveness of dispersants containing Tween 80, Span 80, and dioctyl sodium sulfosuccinate (DOSS) was characterized using a modified Swirling Flask test, and was correlated with both initial and dynamic interfacial tension produced by those dispersants at an oil-water interface. Compositional trends in effectiveness were shown to be governed by: (1) initial oil-water interfacial tension observed upon dispersant-oil-saltwater contact; (2) rate of increase (or decrease) from the initial interfacial tension as DOSS was rapidly lost to the aqueous phase; and (3) gradually slowing kinetics of dispersant adsorption to the oil-water interface as Span 80 concentration was increased, which ultimately diminished dispersion effectiveness considerably even as dynamic interfacial tension remained <10(-3) mN/m. It is proposed that this third phenomenon results not only from the hydrophobicity of Span 80, but also from the dependence of mixed Tween-Span-DOSS reverse micelles' stability in crude oil on dispersant composition.
authors.affiliation: Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455-0331, United States.
authors.forename: David A
authors.initials: DA
authors.lastname: Riehm
authors.affiliation: Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455-0331, United States. Electronic address: mccormic@umn.edu.
authors.forename: Alon V
authors.initials: AV
authors.lastname: McCormick
mesh_terms: D000327:Adsorption; D010578:Petroleum; D059392:Petroleum Pollution; D013501:Surface-Active Agents / Q000737:chemistry*; D014867:Water / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D010578:Petroleum; D013501:Surface-Active Agents; D014874:Water Pollutants, Chemical; D014867:Water
keywords: Corexit; Crude oil; Dispersant; Oil spill; Surfactants