Structure and Dynamics of Aqueous Solutions of Electrolytes in Confined Space.
Structure and Dynamics of Aqueous Solutions of Electrolytes in Confined Space.
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密闭空间电解质水溶液的结构和动力学。
DOI：
10.1143/jpsjs.81sa.sa025
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
and H. Tanaka
中科院分区：
文献类型：
--
作者：
Y. Yamakawa;M. Matsumoto;and H. Tanaka
我们进行等温等压分子动力学模拟的水溶液中的钾和氯离子与不同的管径。在1 ns内达到平衡状态，但达到平衡的弛豫时间取决于离子的初始排列。当管径大于1nm时，离子在几十皮秒内交换它们的轴向位置，成为反离子交替排列的最稳定构型。然而，小于1nm的管中的离子不能在纳秒量级内交换轴坐标中的相互位置。轴向自扩散系数也进行了检查。据发现，他们增加，增加管尺寸一旦达到平衡。这些结果表明，部分水合和脱水对电解质在管道和通道等受限空间中的扩散起着一定的作用。
We perform isothermal-isobaric molecular dynamics simulations of aqueous solutions of potassium and chloride ions with varying tube diameter. An equilibrium state is attained within 1 ns, but the relaxation time to equilibrium is dependent on the initial arrangement of ions. When the tube diameter is larger than 1 nm, ions exchange their axial positions in few tens of picosecond to be the most stable configuration in which counterions are lined up alternately. However, ions in a tube narrower than 1 nm cannot exchange the mutual positions in axial-coordinate within an order of nano second. The axial self-diffusion coefficients are also examined. It is found that they increase with increasing the tube size once an equilibrium is attained. These results suggest the partial hydration and dehydration play a certain role in diffusion of the electrolytes in confined space like tubes and channels.