Abstract
Series of bi-component nonylphenol alkyl sulfonate surfactants (C 12 /C n -NPAS, n = 8, 10, 14, 16) were synthesized through sulfonation-alkylation-neutralization using a mixture of linear alpha olefin (C 12 -olefin and C n -olefin, n = 8, 10, 14, 16), SO 3 and nonylphenol as raw materials. The effect of the raw materials composition on the properties, such as surface tension, interfacial tension, wettability, foam properties of the prepared C 12 /C n -NPAS ( n = 8, 10, 14, 16) surfactants was systematically investigated. The critical micelle concentrations (CMC) of C 12 /C 8 -NPAS, C 12 /C 10 -NPAS, C 12 /C 14 -NPAS and C 12 /C 16 -NPAS are 0.42, 0.26, 0.22 and 0.40 mmol · L −1 , and surface tensions at CMC (γ CMC ) are 34.7, 27.9, 31.8 and 33.3 mN · m −1 , respectively. Compared with SDBS and HABS, the surface properties of the prepared C 12 /C n -NPAS are superior to traditional surfactants. Interfacial tension between Daqing crude oil and weakly alkaline ASP oil flooding system containing 0.1 wt% of C 12 /C 14 -NPAS could reach an ultralow level of 9.78 × 10 −3 mN · m −1 , which is lower than that for C 12 -NPAS and HABS. C 12 /C 10 -NPAS shows better wetting performance and foamability and foam stability than other synthesized surfactants.