Difference between revisions of "Fluorosurfactant"
(New page: Fluorosurfactants, or fluorinated surfactants, are synthetic organofluorine chemical compounds that have multiple fluorine atoms. They can be polyfluorinated or fluorocarbon-based (perfluo...)
Revision as of 08:53, 1 November 2009
Fluorosurfactants, or fluorinated surfactants, are synthetic organofluorine chemical compounds that have multiple fluorine atoms. They can be polyfluorinated or fluorocarbon-based (perfluorinated). As surfactants, they are more effective at lowering the surface tension of water than comparable hydrocarbon surfactants. They have a fluorinated "tail" and a hydrophilic "head." Some fluorosurfactants, such as PFOS, are detected in humans and wildlife.
Physical and chemical properties
Fluorosurfactants can lower the surface tension of water down to a value half of what is attainable by using hydrocarbon surfactants.<ref name=Salager2002>Template:Cite paper</ref> This ability is due to the lipophobic nature of fluorocarbons, as fluorosurfactants tend to concentrate at the liquid-air interface.<ref>Template:Cite web</ref> They are not as susceptible to the London dispersion force, the basis for lipophilicity, because the electronegativity of fluorine reduces the polarizability of the surfactants' fluorinated molecular surface. Therefore, the attractive interactions resulting from the "fleeting dipoles" are reduced, in comparison to hydrocarbon surfactants. Fluorosurfactants are more stable and fit for harsh conditions than hydrocarbon surfactants because of the stability of the carbon–fluorine bond. Likewise, perfluorinated surfactants persist in the environment for that reason.