Dynamic wetting on moving surfaces: A molecular dynamics study

Konstantinos Ritos, Nishanth Dongari, Yonghao Zhang, Jason Reese

Research output: Chapter in Book/Report/Conference proceedingChapter

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.
LanguageEnglish
Title of host publicationNanochannels, Microchannels and Minichannels
Subtitle of host publicationProceedings of the 10th International Conference on Nanochannels, Microchannels and Minichannels
DOIs
Publication statusPublished - 8 Jul 2012
Event10th International Conference on Nanochannels, Microchannels and Minchannels - Puerto Rico, Rio Grande, Puerto Rico
Duration: 8 Jul 201212 Jul 2012

Conference

Conference10th International Conference on Nanochannels, Microchannels and Minchannels
CountryPuerto Rico
CityRio Grande
Period8/07/1212/07/12

Fingerprint

Wetting
Molecular dynamics
Graphite
Silicon
Contact angle
Water
Hysteresis
Hydrogen bonds
Boundary conditions
Computer simulation
Liquids

Keywords

  • molecular dynamics
  • wetting fluid

Cite this

Ritos, K., Dongari, N., Zhang, Y., & Reese, J. (2012). Dynamic wetting on moving surfaces: A molecular dynamics study. In Nanochannels, Microchannels and Minichannels: Proceedings of the 10th International Conference on Nanochannels, Microchannels and Minichannels https://doi.org/10.1115/ICNMM2012-73179
Ritos, Konstantinos ; Dongari, Nishanth ; Zhang, Yonghao ; Reese, Jason. / Dynamic wetting on moving surfaces : A molecular dynamics study. Nanochannels, Microchannels and Minichannels: Proceedings of the 10th International Conference on Nanochannels, Microchannels and Minichannels. 2012.
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Ritos, K, Dongari, N, Zhang, Y & Reese, J 2012, Dynamic wetting on moving surfaces: A molecular dynamics study. in Nanochannels, Microchannels and Minichannels: Proceedings of the 10th International Conference on Nanochannels, Microchannels and Minichannels. 10th International Conference on Nanochannels, Microchannels and Minchannels, Rio Grande, Puerto Rico, 8/07/12. https://doi.org/10.1115/ICNMM2012-73179

Dynamic wetting on moving surfaces : A molecular dynamics study. / Ritos, Konstantinos; Dongari, Nishanth; Zhang, Yonghao; Reese, Jason.

Nanochannels, Microchannels and Minichannels: Proceedings of the 10th International Conference on Nanochannels, Microchannels and Minichannels. 2012.

Research output: Chapter in Book/Report/Conference proceedingChapter

TY - CHAP

T1 - Dynamic wetting on moving surfaces

T2 - A molecular dynamics study

AU - Ritos, Konstantinos

AU - Dongari, Nishanth

AU - Zhang, Yonghao

AU - Reese, Jason

PY - 2012/7/8

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N2 - 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.

AB - 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.

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KW - wetting fluid

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M3 - Chapter

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Ritos K, Dongari N, Zhang Y, Reese J. Dynamic wetting on moving surfaces: A molecular dynamics study. In Nanochannels, Microchannels and Minichannels: Proceedings of the 10th International Conference on Nanochannels, Microchannels and Minichannels. 2012 https://doi.org/10.1115/ICNMM2012-73179