Department of Physics, University of California, San Diego, La Jolla, California 92093-0319, USA.
Phys Rev Lett. 2013 Nov 22;111(21):216804. doi: 10.1103/PhysRevLett.111.216804. Epub 2013 Nov 20.
We study the effect of volumetric constraints on the structure and electronic transport properties of distilled water in a nanopore with embedded electrodes. Combining classical molecular dynamics simulations with quantum scattering theory, we show that the structural motifs water exhibits inside the pore can be probed directly by tunneling. In particular, we show that the current does not follow a simple exponential curve at a critical pore diameter of about 8 Å, rather it is larger than the one expected from simple tunneling through a barrier. This is due to a structural transition from bulklike to "nanodroplet" water domains. Our results can be tested with present experimental capabilities to develop our understanding of water as a complex medium at nanometer length scales.
我们研究了体积约束对纳米孔中嵌入电极的蒸馏水结构和电子输运性质的影响。通过将经典分子动力学模拟与量子散射理论相结合，我们表明可以通过隧道直接探测到孔内水所表现出的结构特征。具体来说，我们发现电流在约 8 Å 的临界孔径处并不遵循简单的指数曲线，而是大于通过简单势垒隧穿所预期的电流。这是由于从块状到“纳米液滴”水域的结构转变所致。我们的结果可以通过目前的实验能力进行测试，以发展我们对纳米尺度下复杂介质水的理解。
