Hotta Takeshi, Kimura Akihiro, Sasai Masaki
Department of Complex Systems Science, Graduate School of Information Science, Department of Physics, Graduate School of Science, and Institute for Advanced Research, Nagoya University, Nagoya 464-8601, Japan, and CREST-JST, Nagoya 464-8601, Japan.
J Phys Chem B. 2005 Oct 6;109(39):18600-8. doi: 10.1021/jp0526039.
The hydration structure around nanometer-size hydrophobic solutes is studied with molecular dynamics simulation by taking aqueous solutions of C60 and C60H60 as examples. In the hydration shell around a single C60 or C60H60, dipoles of simulated water molecules tend to be aligned to form the vortexlike coherent pattern which lasts for 100 ps, while individual water molecules stay within the hydration shell for about 10 ps. This structural pattern organized by fluctuating and diffusively moving molecules should be called a "fluctuating cage". In the narrow region between a pair of C60 molecules or a pair of C60H60 molecules, water density strongly fluctuates and is correlated to the mean force between solutes. The fluctuating caging and drying between solutes affect the hydrophobic interaction and dynamical behaviors of solutes.
以C60和C60H60水溶液为例，通过分子动力学模拟研究了纳米尺寸疏水溶质周围的水化结构。在单个C60或C60H60周围的水化层中，模拟水分子的偶极倾向于排列形成持续100皮秒的涡旋状相干模式，而单个水分子在水化层内停留约10皮秒。这种由波动和扩散运动的分子组成的结构模式应称为“波动笼”。在一对C60分子或一对C60H60分子之间的狭窄区域，水密度强烈波动，并与溶质之间的平均力相关。溶质之间的波动笼合和干涸影响溶质的疏水相互作用和动力学行为。
