Park Jae Hyun, Aluru N R
Department of Mechanical Science and Engineering, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
Appl Phys Lett. 2008 Dec 22;93(25):253104. doi: 10.1063/1.3054640.
In this letter, we investigate using molecular dynamics simulations the diffusion of water submonolayers on hydrophilic surfaces. In contrast to a strong hydrophilic Ag surface, on a weak hydrophilic Pb surface, the diffusion coefficient is remarkably enhanced at a critical surface coverage and a Lambda-shape anomaly with surface coverage is observed, i.e., the diffusion coefficient increases with the increase in surface coverage until a critical surface coverage, beyond which the diffusion coefficient decreases. We explain the anomalous diffusion of water on hydrophilic surfaces by a detailed understanding of molecular cavities and monolayer tail contributing to three-dimensional hydrogen bonding.
在这封信中，我们使用分子动力学模拟研究了水分子亚单层在亲水性表面上的扩散。与强亲水性的银表面不同，在弱亲水性的铅表面上，扩散系数在临界表面覆盖率时显著增强，并且观察到扩散系数随表面覆盖率呈λ形异常，即扩散系数随着表面覆盖率的增加而增加，直到达到临界表面覆盖率，超过该覆盖率后扩散系数下降。我们通过详细了解分子空穴和单层尾部对三维氢键的贡献来解释水分子在亲水性表面上的异常扩散。
