Atomistic Hydrodynamics and the Dynamical Hydrophobic Effect in Porous Graphene

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• 作者：Steven E. Strong ; Joel D. Eaves
• 刊名：The Journal of Physical Chemistry Letters
• 出版年：2016
• 出版时间：May 19, 2016
• 年：2016
• 卷：7
• 期：10
• 页码：1907-1912
• 全文大小：484K
• 年卷期：0
• ISSN：1948-7185

文摘

Mirroring their role in electrical and optical physics, two-dimensional crystals are emerging as novel platforms for fluid separations and water desalination, which are hydrodynamic processes that occur in nanoscale environments. For numerical simulation to play a predictive and descriptive role, one must have theoretically sound methods that span orders of magnitude in physical scales, from the atomistic motions of particles inside the channels to the large-scale hydrodynamic gradients that drive transport. Here, we use constraint dynamics to derive a nonequilibrium molecular dynamics method for simulating steady-state mass flow of a fluid moving through the nanoscopic spaces of a porous solid. After validating our method on a model system, we use it to study the hydrophobic effect of water moving through pores of electrically doped single-layer graphene. The trend in permeability that we calculate does not follow the hydrophobicity of the membrane but is instead governed by a crossover between two competing molecular transport mechanisms.