阴离子孪连表面活性剂的合成及其表/界面活性研究

Study on the Synthesis of Anion Gemini Surfactants and its Surface/Interfacial Activity

合成了疏水链长度不同和连接基长度不同的7种系列阴离子孪连表面活性剂，研究了它们的表／界面活性。结果表明，它们有较低的表面张力和临界胶束浓度（CMC），有很好的表面活性。它们的CMC都在10^-5～10^-6mol／L之间，表面张力在26．5-34mN／m之间。它们有非常好的抗一价、二价盐的能力。除了C16-C2-C16在高于5％的NaCl溶液中会产生析出外，其余孪连表面活性剂都能耐盐20％以上。随着盐浓度的增加，孪连表面活性剂与烷烃间的界面张力逐渐降低，能达到10^-3mN／m。与中原油田原油间的界面张力能降低到10^-3～10^-4mN／m，表明它们可应用于特高矿化度油藏提高采收率。

Seven anionic Gemini surfactants with different length of hydrophobic chains and spacers have been synthesized and their surface/interface activities were studied. The CMC values were in the range of from 10^-5 to 10^-6 mol/L and the values of surface tension were from 26.5 to 34mN/m, which indicate that the Gemini surfactants possess superior surface activity. The Gemini surfactants also show excellent salt tolerant ability toward cations. No precipitate in Gemini surfaetants/NaCl solution even when the salt concentration is up to 20% except for C16-C2-C16 which will be precipitated in 5% NaCl solution. The interface tension between Gemini surfactant solutions and alkanes was reduced along with the increase of salt concentration in aqueous solution, even reach to ultra-low level. The interface tensions between Gemini surfactant solutions and Zhongyuan crude oil could drop to the value of 10^-3 to 10^-4mN/m.