Synthesis and Surface/Interfacial Properties of Novel Dialkyl Disulfonate Gemini Surfactants Derived from 1,3,5-triazine

Abstract

Abstract A series of novel dialkyl disulfonate Gemini surfactants (Cn-GSBS, n = 8, 12, 14, 16, n is the carbon number of the hydrophobic chain) was synthesized from cyanuric chloride, aliphatic amine, ethylenediamine, N,N'-dimethyl-1,3-propyldiamine and sodium 2-chloroethanesulfonate. The chemical structures of the prepared compounds were confirmed by FT-IR and 1H NMR. The critical micelle concentrations (CMC) in aqueous solutions at 25°C were determined by surface tension method. The CMC value decreased with increasing length of the carbon chain. The CMC reached a minimum as low as 5 × 10−5 mol · L−1 for C16-GSBS. The interfacial tensions (IFT) between Daqing crude oil and Cn-GSBS surfactant solutions were also measured. The effects of the concentration of Na2CO3, the concentration and carbon chain length of Cn-GSBS on the IFT of crude oil-water were investigated in detail. The results show that, for the aqueous surfactant system containing the weak base Na2CO3, oil-water interfacial tension can be reduced to 10−2 mN m−1 orders of magnitude. The results also indicate that with the increase of surfactant concentration and the chain length, the oil-water interfacial tension decreased markedly, which indicates that Cn-GSBS surfactants have a good interface activity. These surfactants are good candidates for weak base-surfactant-polymer EOR process.