One F-octyl versus two F-butyl chains in surfactant aggregation behavior
Résumé
An easy synthetic procedure in two or three steps from perfluoroalkylethyl iodide derivatives led to six novel fluorinated carboxylates monomeric and gemini surfactants with respectively one or two hydrophobic tails: RF(C2H4)CH(CO2-)2,2Na+ and [RF(C2H4)]2C(CO2-),Na+ RF =C4F9, C6F13 and C8F17. These anionic surfactants exhibited very low surface tension from 15 to 33 mN/m as well as low critical micelle concentration until 1.3 x 10-4 mol/L. Furthermore the surface properties of the gemini compound with two short fluoroalkyl chains (RF = C4F9) were found to be almost equal to those of the monomeric surfactant with one long fluoroalkyl chain (RF = C8F17), which could provide an interesting alternative to the bioaccumulative long-chain perfluorinated surfactant.