甘氨酸衍生物对油酸钠胶束化的影响

摘要

Two different types of glycine counter-ions,N,N,N-trimethyl glycine methyl ester iodide and sodium N,N,N-trimethyl glycine iodide (GE and SG)were synthesized from N,N-dimethyl glycine methyl ester.The effect of the both glycine counter-ions,GE and SG,on the micellization of sodium oleate (NaOA)was studied by conductivity measurement.It was found that the critical micelle concentration (cmc),counter-ion dissociation degree (α)and Gibbs en-ergy of micellization (DG mic )of aqueous NaOA solution decrease as the concentrations of GE or SG increase.The hydrophobicity of glycine counter-ions contributes mainly to the difference in the thermodynamic parameters,thus methyl ester group of GE is much favorable for forming NaOA micelles.%以 N,N-二甲基甘氨酸甲酯为原料合成了两种甘氨酸衍生物,碘化 N,N,N-三甲基甘氨酸甲酯(GE)和碘化 N,N,N-三甲基甘氨酸钠盐(SG),并利用电导法研究了稀浓度的 GE、SG 对油酸钠(NaOA)胶束化的影响。结果表明,随着反离子 GE、SG 浓度的增加,NaOA/GE 或 SG 体系的临界胶束浓度(cmc)、反离子解离度(α)、胶束化自由能(DG mic )逐渐降低。通过分析这两种反离子的分子结构,我们得出反离子的疏水性是影响这些热力学参数变化的主要因素,疏水性较强的 GE 更有利于油酸钠胶束的形成。