The interfacial tension between oil and gemini surfactant solution

The interfacial tensions between oil and solution of cationic gemini surfactants have been measured. It is found that gemini surfactants are more effective and efficient than corresponding conventional surfactants in reducing the interfacial tension and can lower the tension of kerosene-water interface to ultra-low at very low concentration without other additives. It is also found that gemini surfactants can reduce the interfacial tension to ultra-low only at a certain concentration range. The addition of salt results in more effectiveness of surfactant in reducing the tension of kerosene- water interface and shows that gemini surfactant has a good synergism with salt. For crude oil from Zhongyuan Oil Field of China, gemini surfactant is more effective on lowering crude oil-water tension and has an excellent ability in reducing the tension of crude oil-water interface. However, when the oil is hexadecane, ultra-low interfacial tension is not observed. (C) 2004 Elsevier B.V. All rights reserved.