Synthesis and properties of novel betaine fluorocarbon surfactants

In this study, a series of new betaine fluorocarbon surfactants (abbreviated as FSC-m) were synthesized with N,N-dimethyl-1,3-propane diamine, perfluoroalkyl sulfonyl fluoride, and sodium chloroacetate. The novel surfactants were characterized by FI-IR, 1H-NMR and 19F-NMR. The surface activity of these surfactants at the air-water interface was investigated. The oil-water interfacial tension, adsorption, and wettability were studied on the oily drilling cuttings. The results showed that the novel surfactants have excellent surface and interfacial activities and low CMC. The novel surfactants can rapidly absorb at oily drilling cuttings, and their isotherm adsorption curve is L-shaped, with single-molecule Langmuir adsorption characteristics. FSC-m dramatically affected the wettability of oily drilling cuttings, such that the oil drop contact angle increased to 75.5° and the water drop contact angle increased to 117.2°, thus reducing the adhesion of the oil phase to the drilling cuttings. These surfactants can be applied to the oil removal technology of oily drilling cutting and they have a broad application prospect.