Slip divergence of water flow in graphene nanochannels: the role of chirality
| Autor: | Elton Oyarzua, Enrique Wagemann, Jens Honore Walther, Harvey A. Zambrano |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Physics
Graphene Water flow General Physics and Astronomy Nanotechnology 02 engineering and technology Slip (materials science) Mechanics 010402 general chemistry 021001 nanoscience & nanotechnology Critical value 01 natural sciences 0104 chemical sciences law.invention Shear rate law Critical resolved shear stress Shear stress Fluid dynamics Physical and Theoretical Chemistry 0210 nano-technology |
| Zdroj: | Physical Chemistry Chemical Physics. 19:8646-8652 |
| ISSN: | 1463-9084 1463-9076 |
| Popis: | Graphene has attracted considerable attention due to its characteristics as a 2D material and its fascinating properties, providing a potential building block for nanofabrication. In nanochannels the solid-liquid interface plays a non-negligible role in determining the fluid dynamics. Therefore, for an optimal design of nanofluidic devices, a comprehensive understanding of the slippage in a water flow confined between graphene walls is important. In nanoconfinement, experimental and computational studies have found the slip length to increase nonlinearly when the shear rate is larger than a critical value. Here, by conducting molecular dynamics simulations, we study the influence of the graphene crystallographic orientation on the slip boundary conditions inside a nanoslit channel. The flow in channels with heights of 2.0, 2.4 and 2.8 nm is driven parallel to the zig-zag and arm-chair crystallographic directions. We extract flow rates, velocity profiles, slip velocities and slip lengths. The slip velocity displays a linear relationship to the shear stress up to a critical value, which is not size dependent. Moreover, the slip length is found to be shear stress dependent above a critical shear stress value of 0.4 MPa. Furthermore, our results indicate that after this critical shear stress is reached, the flow rates are significantly influenced (up to 10%) by the particular orientation of the graphene topology. |
| Databáze: | OpenAIRE |
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