Slippage of water over hydrophobic surfaces

Vinogradova, Olga I.

doi:10.1016/s0301-7516(98)00041-6

Cited by 419 publications

(299 citation statements)

References 48 publications

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“…For strong liquid-wall interaction the contact angle is low (Q < 908) or the liquid even wets the solid completely (Q = 0). Computer simulations [1016][1017][1018][1019][1020] and experiments confirmed that for low fluid-wall interactions slippage occurs [1009,1021,1022].…”

Section: Introductionmentioning

confidence: 61%

“…[1029,1030]). It is now generally accepted that slip occurs for liquids on lyophobic surfaces, for example for water on hydrophobic surfaces [1009]. This is a result of a number of experiments with the AFM and other techniques.…”

Section: Methodsmentioning

confidence: 99%

“…A possible slip was only discussed in the mainstream literature for polymer melts [1007,1008]. Recent experiments, however, indicated that fluids might slip past smooth surfaces [1009][1010][1011][1012][1013][1014]. The hydrodynamic boundary condition to describe slippage is [1015] …”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Force measurements with the atomic force microscope: Technique, interpretation and applications

Butt

Cappella

Kappl

2005

Surface Science Reports

3,151

2,949

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Section: Introductionmentioning

confidence: 61%

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Force measurements with the atomic force microscope: Technique, interpretation and applications

Butt

Cappella

Kappl

2005

Surface Science Reports

3,151

2,949

View full text Add to dashboard Cite

“…The first assumption is that the basic flow in the gas layer essentially shows the same behaviour as the flow in the liquid layer. This means in the Couette flow case that a flow with a constant (albeit higher) shear rate develops in the gas layer (Vinogradova 1999). In the pressure-driven cases it would be assumed (as in the case of PCAF Joseph et al 1997) that the same mean streamwise pressure gradient Π acts as in the liquid layer, Π G = Π L .…”

Section: Basic Assumptionsmentioning

confidence: 99%

“…The assumption that the gas on a superhydrophobic surface is trapped, i.e. zero net mass flow downstream, leads to different results for change in drag, the optimum air layer thickness and apparent slip length compared to h h R Gas Gas Gas Gas Gas previous approaches (Joseph, Nguyen & Beavers 1984;Than, Rosso & Joseph 1987;Vinogradova 1999) where a finite mass flow rate is allowed in the air layer.…”

Section: Introductionmentioning

confidence: 99%

Change in drag, apparent slip and optimum air layer thickness for laminar flow over an idealised superhydrophobic surface

et al. 2013

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Analytic results are derived for the apparent slip length, the change in drag and the optimum air layer thickness of laminar channel and pipe flow over an idealised superhydrophobic surface, i.e. a gas layer of constant thickness retained on a wall. For a simple Couette flow the gas layer always has a drag reducing effect, and the apparent slip length is positive, assuming that there is a favourable viscosity contrast between liquid and gas. In pressure-driven pipe and channel flow blockage limits the drag reduction caused by the lubricating effects of the gas layer; thus an optimum gas layer thickness can be derived. The values for the change in drag and the apparent slip length are strongly affected by the assumptions made for the flow in the gas phase. The standard assumptions of a constant shear rate in the gas layer or an equal pressure gradient in the gas layer and liquid layer give considerably higher values for the drag reduction and the apparent slip length than an alternative assumption of a vanishing mass flow rate in the gas layer. Similarly, a minimum viscosity contrast of four must be exceeded to achieve drag reduction under the zero mass flow rate assumption whereas the drag can be reduced for a viscosity contrast greater than unity under the conventional assumptions. Thus, traditional formulae from lubrication theory lead to an overestimation of the optimum slip length and drag reduction when applied to superhydrophobic surfaces, where the gas is trapped.

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Numerical Simulation of Multiphase Flow in Nanoporous Organic Matter With Application to Coal and Gas Shale Systems

Song

et al. 2018

Water Resources Research

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Fluid flow in nanoscale organic pores is known to be affected by fluid transport mechanisms and properties within confined pore space. The flow of gas and water shows notably different characteristics compared with conventional continuum modeling approach. A pore network flow model is developed and implemented in this work. A 3‐D organic pore network model is constructed from 3‐D image that is reconstructed from 2‐D shale SEM image of organic‐rich sample. The 3‐D pore network model is assumed to be gas‐wet and to contain initially gas‐filled pores only, and the flow model is concerned with drainage process. Gas flow considers a full range of gas transport mechanisms, including viscous flow, Knudsen diffusion, surface diffusion, ad/desorption, and gas PVT and viscosity using a modified van der Waals' EoS and a correlation for natural gas, respectively. The influences of slip length, contact angle, and gas adsorption layer on water flow are considered. Surface tension considers the pore size and temperature effects. Invasion percolation is applied to calculate gas‐water relative permeability. The results indicate that the influences of pore pressure and temperature on water phase relative permeabilities are negligible while gas phase relative permeabilities are relatively larger in higher temperatures and lower pore pressures. Gas phase relative permeability increases while water phase relative permeability decreases with the shrinkage of pore size. This can be attributed to the fact that gas adsorption layer decreases the effective flow area of the water phase and surface diffusion capacity for adsorbed gas is enhanced in small pore size.

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Slippage of water over hydrophobic surfaces

Cited by 419 publications

References 48 publications

Force measurements with the atomic force microscope: Technique, interpretation and applications

Force measurements with the atomic force microscope: Technique, interpretation and applications

Change in drag, apparent slip and optimum air layer thickness for laminar flow over an idealised superhydrophobic surface

Numerical Simulation of Multiphase Flow in Nanoporous Organic Matter With Application to Coal and Gas Shale Systems

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