Surface Activity, Aggregation Behavior, Wettability, and Foam Properties of Mixed System of Gemini Cationic Silicon Surfactant and Betaine Hydrocarbon Surfactant in Dilute Solutions

This paper reports the synthesis of a novel organosilicon cationic Gemini surfactant (GSC-12C) and the surface properties of GSC-12C/cocamidopropyl betaine (CAB) aqueous solution. GSC-12C exhibited high surface activity in aqueous solution, with the critical micelle concentration (CMC) of 0.20 mmol/L, and the corresponding surface tension (γCMC) was 20.7 mN/m, which is superior to that of the perfluorooctanesulfonate (C7F15COONa, CMC = 31.2 mmol/L,γCMC = 24.7 mN/m). It had the ability to comprehensively replace perfluorinated surfactants. Moreover, when the gemini cationic organosilicon surfactant (GSC-12C) was compounded with common hydrocarbon surfactants, it was found that it had a good synergistic effect with CAB and could enhance the foaming and foam-stabilizing abilities of the surfactant. Additionally, the GSC-12C solution exhibited excellent wettability, enabling the PTFE membrane to be nearly completely wetted at a very low concentration (1 mmol/L). This work broadens the ideas for the preparation and formulation of high-performance specialty surfactants.