摘要
利用NMR技术的自扩散、自旋-自旋弛豫时间(T2)和自旋-晶格弛豫时间(T1)以及二维NOESY谱,研究了n-十二烷基-β-D-麦芽糖苷(DM)与十二烷基三甲基氯化铵(DTAC)的二元混合体系中混合胶束的形成、大小变化、排列方式、复配比例和相互作用点等.NMR的自扩散系数表明了混合胶束的大小主要取决于DM分子,T2/T1显示混合胶束堆积的较紧密,两分子的疏水链是以肩并肩的方式位于胶束核中,2D NOESY谱表明DTAC分子中与极头相连的亚甲基邻近DM分子中倒数第二个糖环,产生分子间相互作用,其相互作用和分子间距的大小随DM/DTAC比例的不同而变化,DM/DTAC在1∶4和1∶8之间是较好的复配比例范围,并确定混合前后出现的相反变化T2值是混合胶束中产生相互作用的证据.
The mixed micellar size, relative arrangement and interaction sites of the nonionic sugar-based surfactant n-dodecyl-β-D-maltoside （DM） and dodecyl trimethyl ammonium chloride were studied using NMR by self-diffusion coefficient, spin-spin and spin-lattice relaxation time, and two-dimensional nuclear Overhauser enhancement （2D NOESY）. Self-diffusion coefficient suggests that the size of the mixed micelles is largely dependent on the DM. The small T2/T1 values suggest tight molecular packing in the mixed micelles of DM and DTAC. 2D NOESY results reveal that the methylene group next to the ammonium head is in the near vicinity of penultimate sugar ring, and the two hydrophobic chains of DM and DTAC molecules are side by side in the interior of the micellar core. The inter-molecular interaction and distance are changed with the difference of DM/DTAC ratios. DM/DTAC ratios of 1 ： 4 to 1 ： 8 are better than other ratios for synergistic performance. The intermolecular interaction was supported by the contrary changes of spin-spin relaxation time （T2） after mixing.
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
2008年第17期1949-1954,共6页
Acta Chimica Sinica
基金
河北省优秀专家出国培训基金(No.200311)资助项目.
