Shiomi J, Maruyama S
Department of Mechanical Engineering, The University of Tokyo, Tokyo, Japan.
Nanotechnology. 2009 Feb 4;20(5):055708. doi: 10.1088/0957-4484/20/5/055708. Epub 2009 Jan 12.
In this work, by means of molecular dynamics simulations, we consider the mass transport of a water cluster inside a single-walled carbon nanotube (SWNT) with a diameter of about 1.4 nm. The influence of the non-equilibrium thermal environment on the confined water cluster has been investigated by imposing a longitudinal temperature gradient on the SWNT. It is demonstrated that the water cluster is transported with an average acceleration proportional to the temperature gradient. Additional equilibrium simulations suggest that the temperature dependence of the potential energy of the confined water is sufficient to realize the transport. In particular, for a system with a hydrophobic interface, the water-water intrinsic potential energy appears to play a dominant role. The transport simulations were also performed for a system with a junction between two different SWNTs. The results suggest that an angstrom difference in diameter may result in a large barrier for water being transported through a small diameter SWNT.
在这项工作中，我们通过分子动力学模拟，研究了直径约为1.4纳米的单壁碳纳米管（SWNT）内水团簇的质量输运。通过在SWNT上施加纵向温度梯度，研究了非平衡热环境对受限水团簇的影响。结果表明，水团簇以与温度梯度成正比的平均加速度进行输运。额外的平衡模拟表明，受限水势能的温度依赖性足以实现这种输运。特别是，对于具有疏水界面的系统，水-水固有势能似乎起主导作用。我们还对两个不同SWNT之间有连接点的系统进行了输运模拟。结果表明，直径上埃级的差异可能会给水流经小直径SWNT造成很大的障碍。
