Preparation And Properties Of The New Zwitterionic Gemini Surfactant

Because surfactants play a very important role in industrial and agricultural production and daily life, exploring novel surfactants with high surface activity is important in theoretical research and practical application. In order to improve the salt tolerance capability, five series of Gemini surfactants were synthesized in this dissertation, and properties were researched. Some achievements are as fellows:1. In the dissertation, a family of zwitterionic Gemini surfactants was synthesized using 1,2-ethylenediamine or 1,6-diaminohexane. The intermediates and the products were purified, and then were confirmed by 1H NMR and IR spectra.2. A family of zwitterionic Gemini surfactants was synthesized through the improvement of the cationic surfactant. The intermediates and the products were purified, and then were confirmed by 1H NMR and IR spectra.3. Three cationic Gemini surfactants were synthesized with the long chain fatty acid. The intermediates and the products were purified and then were confirmed by 1H NMR and IR spectra.4. A new zwitterionic Gemini surfactant was synthesized with glycol. It was purified and then was confirmed by 1H NMR and IR spectra.5. The critical micelle concentration (cmc) values and the surface tension at their cmc(γcmc)values of the Gemini surfactants were measured. The results show that the values of cmc were between 1×10-3mol/L and 1×10-4mol/L, and the values ofγcmc were between 32 mN/m and 40mN/m.6. The interfacial tensions of the Gemini surfactants with Daqing oilfield crude oil were studied. The results show that the Gemini surfactants through the improvement of cationic surfactants and the Gemini surfactants using glycol as raw material can lower the oil/water interfacial tension to 10-1 mN/m, but the Gemini surfactants using 1,2-ethylenediamine, 1,6-diaminohexane or long chain fatty acid as raw materials can lower the oil/water interfacial tension to ultra-low level at appropriate conditions. So these surfactants show great prospects in application to the tertiary oil recovery technology in the future.7. Using suspension liquid quantitative method, bactericidal properties of the Gemini surfactants were tested, and the results show that the Gemini surfactants have good bactericidal properties.