Zhu Jianzhuo, Lan Yueqiang, Du Huijing, Zhang Yuanhang, Su Jiguo
College of Science, Yanshan University, Qinhuangdao 066004, China.
Phys Chem Chem Phys. 2016 Jul 21;18(27):17991-6. doi: 10.1039/c6cp00610h. Epub 2016 Jun 21.
The transport properties of water through a nanochannel influenced by the direction of an external electric field has been investigated by using molecular dynamics simulations. Water molecules flow unidirectionally across the nanochannel under a uniform external electric field without an osmotic pressure. It is found that the direction of the external field plays an important role in the interactions and dipole orientations of water molecules in the nanochannel, accordingly changing the net water flux dramatically. Most importantly, a critical angle (θC) between the external field and the nanochannel axis is found. The average net water flux increases as θ increases for θ≤θC but decreases sharply to a near-zero value for a further increase of θ. The maximum value of the average net water flux is 7.33 times as high as the value when the electric field is along the nanochannel axis. Our findings are of great practical importance for nanomolecular engineering, which provide a possible strategy for designing novel controllable water nanopumps.
通过分子动力学模拟研究了外部电场方向对水通过纳米通道传输特性的影响。在没有渗透压的均匀外部电场作用下，水分子单向流过纳米通道。研究发现，外部电场的方向在纳米通道中水分子的相互作用和偶极取向中起着重要作用，从而显著改变净水通量。最重要的是，发现了外部电场与纳米通道轴之间的临界角（θC）。对于θ≤θC，平均净水通量随θ的增加而增加，但当θ进一步增加时，平均净水通量急剧下降至接近零的值。平均净水通量的最大值是电场沿纳米通道轴时的7.33倍。我们的发现对纳米分子工程具有重要的实际意义，为设计新型可控水纳米泵提供了一种可能的策略。
