Synthesis and surface activity study of branched fluorinated cationic (FCS), gemini (FGS) and amphoteric (FAS) surfactants with CF3CF2CF2C(CF3)2 group

•Three novel branched fluorinated surfactants were synthesized.•The approach for the preparation of the title compounds was easy to achieve.•FCS has the ability to reduce the surface tension of water to below 20 mN/m.•FAS has excellent efficiency, its cmc value is about 1.04 × 10−4 mol/L at 298 K.•All the surfactants’ surface activities are better than that of C7F15COONa.

Fluorinated surfactants are usually composed of a perfluorinated chain and a hydrophilic group. Academic surveys have reported that straight chain fluorinated surfactants have the lowest surface tension in a relatively high concentration while the branched fluorinated surfactants show more efficient in a relatively low concentration. Introducing branch is one of effective strategies for synthesis of non-bioaccumulable fluorinated surfactants.Three novel branched fluorinated surfactants were designed and prepared through a five-step route using perfluoro-2-methyl-2-pentene as starting material. The surface activities of them were investigated and found that they exhibited excellent surface activities. FCS can reduce the surface tension of water to below 20 mN/m, and the cmc value of FAS in water is about 1.04 × 10−4 mol/L at 298 K. All the values of surface properties of FCS, FGS and FAS are lower than that of sodium perfluorooctanoate.

Graphical abstractThree novel branched fluorinated surfactants were designed and prepared through a five-step route using perfluoro-2-methyl-2-pentene as starting material. FCS can reduce the surface tension of water to below 20 mN/m and the cmc value of FAS in water is about 1.04 × 10−4 mol/L at 298 K. All the values of surface properties of FCS, FGS and FAS are lower than that of sodium perfluorooctanoate.Figure optionsDownload full-size imageDownload as PowerPoint slide