Study On Structure And Properties Of Anionic Gemini Surfactants

Some properties of anionic Gemini surfactants were studied in this paper to obtain a good one to efficiently enhance oil recovery. This project would have great prosperity in view of the supply of energy.Since its headgroups were connected by chemical bonds and the repulsion between the two ionic headgroups was weakened, it has greater surface activity than conventional monomeric ones. Recently a great deal of work has been done on Gemini surfactants. But further research has to be done. Due to some good properties of the anionic Gemini surfactants synthesized, we studied its feasibility to enhance oil recovery.The overall results as following:1 CMC,γcmc and C20 of Gemini surfactants were studied and it was found that the Gemini surfactants were about one order of magnitude more efficient at forming micelles(CMC) than conventional surfactants. For γcmc only, Gemini surfactants didn't show great advantages over conventional monomeric ones. But it is more efficient in declining surface tension of the water.2 Aggregation numbers(N) and microstructure of Gemini surfactants were investigated as functions of spacer length and concentration. Upon increasing the spacer length, the spacer became more flexible and aggregation number is increasing. Gemini surfactants have greater tendency in forming liquid crystal. than conventional surfactant--SDBS as shown in TEM photoes.3 Some application properties of Gemini surfactants were studied. By DTA analysis, it was found that the original decomposition temperatures of Gemini A-D were all far beyond the temperature of oil field underground. The interficial tension between oil and water could be declined to 10-3mN/m at the concentration of Gemini H 0.1%, and it shows great capacity in declining interfacial tension between oil and water. When added to PAM solution, Gemini H would not make the viscosity of the solution decline. However, in certain concentration range it could increase the viscosity of the solution. We can come to the conclusion that Gemini H could be used as one component of oil-flooding agent to increase oil recovery.4 Formation of mid-phase microemulsion of Gemini H was studied and its optimal composition was as follows: C Gemini H(％)＝0.1～0.5；C 正己醇(％)＝2.0～4.0；C 氯化钠(％)＝1.5～2.5...