【摘要】 为研究枝状连接基对Gemini咪唑表面活性剂性能的影响,以2,2-双(溴甲基)-1,3-丙二醇为连接基合成枝状的Gemini咪唑表面活性剂2,4-二(溴化-3-烷基咪唑)-1,3-丙二醇([Cn-P-Cn]Br2),其中n=10,12,14.通过表面张力法和电导法测量其表面活性并计算25℃时胶束形成的各项性能参数:临界胶束浓度(ccmc)、表面饱和吸附量(Γcmc)、表面活性剂分子在空气/水界面的最小横截面积(Amin)、效率因子(pC20)和表面压(πcmc)等.结果表明,不同链长的3种表面活性剂具有很高的表面活性,所有表面活性剂胶束形成的吉布斯自由能(ΔGm)均为负值,说明常温常压下胶束的形成是自发过程.更多还原

【Abstract】 To study the effect of branched spacer on the property of Gemini imidazolium surfactants,Gemini imidazolium surfactants of 2,4-[bis(3-alkylimidazolium-1-yl) bromide]-1,3-propanediol([Cn-P-Cn]Br2,where n is the hydrocarbon chain length of 10,12 or 14) were synthesized with 2,2-dibromomethyl-1,3-propanediol as the spacer.Their surface activity and thermodynamic properties of micellization were characterized by surface tension and electrical conductivity measurements.The values of critical micelle concentration(ccmc),saturation adsorption values at the air/aqueous interface(Γmax),the area per surfactant molecule at the air/aqueous interface(Amin),the efficiency of adsorption(pC20) and surface pressure(πcmc) derived from surface tension measurement at 25 ℃ suggested that the surface activity of [Cn-P-Cn]Br2 was high.While Gibbs Free Energy of micellization(ΔGm) of all the surfactants derived from electrical conductivity were all negative,indicating that the formation of micelles was spontaneous.更多还原