脉冲场梯度NMR测定六元微乳体系中组分的自扩散系数  

Self-diffusion measurements of the hexahydric microemulsion system by pulsed-gradient NMR

作　　者：胡海燕[1] 陈小娟[2] 陈六平[2] 黄世亮[1] 王荣昌[1] 张志荣[3] 

机构地区：[1]中山大学药学院,广州510080 [2]中山大学化学与化学工程学院,广州510275 [3]四川大学靶向药物教育部重点实验室,成都610041

出　　处：《四川大学学报（自然科学版）》2007年第4期855-860,共6页Journal of Sichuan University(Natural Science Edition)

摘　　要：用脉冲场梯度NMR测定了Cremophor EL/大豆磷脂/乙醇/丙二醇/水/Labrafaccc六元体系单相区中A→I点水、丙二醇、Labrafaccc和Cremophor EL的自扩散系数.从单相区A点(水、油含量分别为12%和18%)向水的顶点稀释得到B、C点,向油的顶点稀释得到D、E点,HI、两点表面活性剂含量与D点的相等,这三点油含量依次为20%、40%和30%.随体系中油含量的升高,油的相对自扩散系数总体呈升高趋势,而丙二醇和水的相对自扩散系数则呈下降趋势.在油水含量相当的区域,Cremophor EL的相对自扩散系数较富油或富水区域高.实验结果表明,相对自扩散系数可用以表征六元微乳体系的结构.丙二醇与Cremophor EL相对自扩散系数与理论值存在一定的偏差,这可能与表面活性剂烷烃链对油分子的溶剂化作用及两组分黏度较大有关.Self-diffusion coefficients of water, propyl glycol （PG）, Labrafaccc and Cremophor EL in the hexahydric system comprised of Cremophor EL, soybean lecithin, ethanol, propyl glycol, water and Labrafaccc were measured by the pulsed-gradient NMR method. All the points chosen to measure self-diffusion coefficients were located in the single phase region of the pseudo-ternary phase diagram. Point B and C were gained by diluting point A to the peak of aqueous phase which contained 12% aqueous phase and 18% oil phase, while point D and E by diluting point A to the peak of oil phase. The total surfactant contents of point H and I were equal to the point D with 55% but distinguished by oil contents with 20%, 40% and 30%, respec- tively. Observed relative self-diffusions of oil increased as a whole when oil contents increased in the system.The opposite was obtained for PG and water. The relative self-diffusion coefficients of Cremophor EL were remarkably higher in the systems of equivalent oil and water than those rich in oil or water. These results indicated that self-diffuslon coefficients could be used to deduce structures of complicated microemulsion systems. Self-diffusion coefficients of PG and Cremophor EL were much larger than those described in single quaternary systems, which could due to viscosity variations of systems and the solvation of hydrocarbon chains of surfactants to oil.

关 键 词：脉冲场梯度NMR 微乳 六元体系 自扩散系数 

分 类 号：O64[理学—物理化学]