Abstract
We report molecular dynamics (MD) simulations of the dynamic wetting of nanoscale droplets on moving surfaces. The dynamic water contact angle and contact angle hysteresis are measured as a function of capillary number on smooth silicon and graphite surfaces. The hydrogen bonding and density profile variations are also reported, and the width of the water depletion layer is evaluated for droplets on three different static surfaces: silicon, graphite and a fictitious super-hydrophobic surface. Our results show that molecular displacements at the contact line are mostly influenced by interactions with the solid surface, while the viscous dissipation effects induced through the movement of surfaces are found to be negligible, especially for hydrophobic surfaces. This finding is in contrast with the wetting dynamics of macroscale droplets, which show significant dependence on the capillary number. This study may yield new insight into surface-wettability characteristics of nano droplets, in particular, developing new boundary conditions for continuum solvers for liquid flows in micro- and nanoscale devices.
Original language | English |
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Title of host publication | Nanochannels, Microchannels and Minichannels |
Subtitle of host publication | Proceedings of the 10th International Conference on Nanochannels, Microchannels and Minichannels |
DOIs | |
Publication status | Published - 8 Jul 2012 |
Event | 10th International Conference on Nanochannels, Microchannels and Minchannels - Puerto Rico, Rio Grande, Puerto Rico Duration: 8 Jul 2012 → 12 Jul 2012 |
Conference
Conference | 10th International Conference on Nanochannels, Microchannels and Minchannels |
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Country | Puerto Rico |
City | Rio Grande |
Period | 8/07/12 → 12/07/12 |
Keywords
- molecular dynamics
- wetting fluid