Center for Computational Science, Graduate School of Engineering, Nagoya University, Nagoya 464-8603, Japan.
Department of Applied Chemistry, Nagoya University, Nagoya 464-8603, Japan.
J Chem Phys. 2017 Jul 21;147(3):034906. doi: 10.1063/1.4994698.
The surface structure and its fluctuation of spherical micelles were investigated using a series of density correlation functions newly defined by spherical harmonics and Legendre polynomials based on the molecular dynamics calculations. To investigate the influence of head-group charges on the micelle surface structure, ionic sodium dodecyl sulfate and nonionic octaethyleneglycol monododecylether (CE) micelles were investigated as model systems. Large-scale density fluctuations were observed for both micelles in the calculated surface static structure factor. The area compressibility of the micelle surface evaluated by the surface static structure factor was tens-of-times larger than a typical value of a lipid membrane surface. The structural relaxation time, which was evaluated from the surface intermediate scattering function, indicates that the relaxation mechanism of the long-range surface structure can be well described by the hydrostatic approximation. The density fluctuation on the two-dimensional micelle surface has similar characteristics to that of three-dimensional fluids near the critical point.
采用基于分子动力学计算的球谐函数和勒让德多项式新定义的一系列密度相关函数，研究了球形胶束的表面结构及其涨落。为了研究头基电荷对胶束表面结构的影响，选择离子型十二烷基硫酸钠和非离子型辛基聚氧乙烯醚（CE）胶束作为模型体系。在计算得到的表面静态结构因子中，观察到两种胶束均存在较大的表面密度涨落。由表面静态结构因子评估的胶束表面可压缩性比典型脂质膜表面大数十倍。由表面中间散射函数评估的结构弛豫时间表明，长程表面结构的弛豫机制可以很好地用静压近似来描述。二维胶束表面上的密度涨落与临界点附近的三维流体具有相似的特征。
