Surface activity and wetting behavior of branched short-chain anionic perfluorinated/cationic hydrocarbon surfactant blends in dilute solutions

Conventional perfluorooctane sulfonyl fluorosurfactants (PFOS) have caused great harm to human health and the environment, but the irreplaceable properties of fluorosurfactants offer great values. To this end, we have synthesized a highly surface active, environmentally friendly sulfonate surfactant (PBSA) with a perfluorinated branched short chain and systematically investigated its thermal stability, surface properties, wetting performance, and so forth. The minimal surface tension (gamma CMC) and critical micelle concentration (CMC) of the aqueous solution of PBSA were 22.70 mN/m and 0.067 mmol/L, respectively. In addition, the binary system of PBSA and cetyltrimethylammonium bromide (CTAB) exhibited excellent synergistic effects: gamma CMC and CMC values were reduced to 18.94 mN/m and 0.008 mmol/L. Moreover, the PBSA/CTAB mixed solution exhibited superb wetting ability: it could achieve complete wetting of PTFE plates at low concentrations (1.82 x 10-3 mol/L), with a minimum wetting concentration of only 2.84 x 10-5 mol/L.