Hybrid CO₂-philic Surfactants with Low Fluorine Content

The relationships between molecular architecture, aggregation, and interfacial activity of a new class of CO₂-philic hybrid surfactants are investigated. The new hybrid surfactant CF2/AOT4 [sodium (4<i>H</i>,4<i>H</i>,5<i>H</i>,5<i>H</i>,5<i>H</i>-pentafluoropentyl-3,5,5-trimethyl-1-hexyl)-2-sulfosuccinate] was synthesized, having one hydrocarbon chain and one separate fluorocarbon chain. This hybrid H–F chain structure strikes a fine balance of properties, on one hand minimizing the fluorine content, while on the other maintaining a sufficient level of CO₂-philicity. The surfactant has been investigated by a range of techniques including high-pressure phase behavior, UV–visible spectroscopy, small-angle neutron scattering (SANS), and air–water (a/w) surface tension measurements. The results advance the understanding of structure–function relationships for generating CO₂-philic surfactants and are therefore beneficial for expanding applications of CO₂ to realize its potential using the most economic and efficient surfactants