On the Origin of the Bump in the Profile of Surface-Tension-Gradient-Driven Spreading Films

1991 ◽  
Vol 248 ◽  
Author(s):  
P. Carles ◽  
A.M. Cazabat
Keyword(s):  
Surface Tension ◽  
Steady State ◽  
Contact Line ◽  
Surface Tension Gradient ◽  
Simple Analysis

AbstractWe show that the presence of a bump, in the profile of spreading films driven by forces such as surface tension gradients, can be explained by a simple analysis of the steady-state velocity, without taking into account contact line effects.

Breakdown of Evaporating Falling Films as a Function of Surface Tension Gradient

1996 ◽  
Vol 17 (4) ◽  
pp. 72-81 ◽  
Author(s):  
ALI G. BUDIMAN ◽  
C. FLORIJANTO ◽  
J. W. PALEN
Keyword(s):  
Surface Tension ◽  
Surface Tension Gradient ◽  
Falling Films

scholarly journals Effect of a surface tension gradient on the slip flow along a superhydrophobic air-water interface

2018 ◽  
Vol 3 (3) ◽  
Author(s):  
Dong Song ◽  
Baowei Song ◽  
Haibao Hu ◽  
Xiaosong Du ◽  
Peng Du ◽  
...  
Keyword(s):  
Surface Tension ◽  
Slip Flow ◽  
Surface Tension Gradient ◽  
Water Interface ◽  
Air Water Interface

Numerical Simulation of Oil-Droplet Cleavage by Surfactant

1996 ◽  
Vol 118 (2) ◽  
pp. 201-209 ◽  
Author(s):  
Xiaoyi He ◽  
Micah Dembo
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Surface Tension ◽  
Large Deformation ◽  
Concentration Gradient ◽  
Surface Tension Gradient ◽  
Oil Droplets ◽  
Numerical Computations ◽  
Oil Droplet ◽  
Pure Surface

We present numerical computations of the deformation of an oil-droplet under the influence of a surface tension gradient generated by the surfactant released at the poles (the Greenspan experiment). We find this deformation to be very small under the pure surface tension gradient. To explain the large deformation of oil droplets observed in Greenspan’s experiments, we propose the existence of a phoretic force generated by the concentration gradient of the surfactant. We show that this hypothesis successfully explains the available experimental data and we propose some further tests.

scholarly journals Tackling the Short-Lived Marangoni Motion Using a Supramolecular Strategy

CCS Chemistry ◽  
2019 ◽  
Vol 1 (2) ◽  
pp. 148-155 ◽  
Author(s):  
Mengjiao Cheng ◽  
Dequn Zhang ◽  
Shu Zhang ◽  
Zuankai Wang ◽  
Feng Shi
Keyword(s):  
Surface Tension ◽  
Electricity Generation ◽  
Adsorption Equilibrium ◽  
Molecular Level ◽  
Surface Tension Gradient ◽  
Aggregation State ◽  
Physical Limit ◽  
Competitive Kinetics ◽  
Air Liquid Interface ◽  
Spontaneous Motion

Inspired by the intriguing capability of beetles to quickly slide on water, scientists have long translated this surface-tension-gradient–dominated Marangoni motion into various applications, for example, self-propulsion. However, this classical spontaneous motion is limited by a short lifetime due to the loss of the surface tension gradient. Indeed, the propellant of amphiphilic surfactants can rapidly reach an adsorption equilibrium and an excessive aggregation state at the air/liquid interface. Here, we demonstrate a supramolecular host–guest chemistry strategy that allows the breaking of the physical limit of the adsorption equilibrium and the simultaneous removal of surfactant molecules from the interface. By balancing the competitive kinetics between the two processes, we have prolonged the lifetime of the motion 40-fold. Our work presents an important advance in the query of long-lived self-propulsion transport through flexible interference at the molecular level and holds promise in electricity generation applications .

Long Term Dynamics of Water-Entry Cavity

2010 ◽  
Author(s):  
Roderick R. La Foy ◽  
Sunghwan Jung ◽  
Pavlos Vlachos
Keyword(s):  
Surface Tension ◽  
Internal Pressure ◽  
Potential Flow ◽  
Water Entry ◽  
Cavity Volume ◽  
Fluid Interface ◽  
Simple Analysis ◽  
Liquid Pressure ◽  
Air Cavity

Many engineering applications involve the motion of objects crossing a fluid interface. The dynamics of this process are often complicated due to the interplay of surface tension, gravity, and inertia. Nevertheless, a simple analysis using potential flow theory works well to predict the interfacial profile of the air cavity formed during an impact. Most current theories however, cannot predict the behavior of the air cavity after pinch off occurs. We therefore investigated the long term dynamics of water entry in both experiment and theory. It was found that shortly after pinch off the cavity dynamics become governed primarily by thermodynamic gas relations. The internal pressure slowly rises due to the cavity volume decreasing while the ambient liquid pressure quickly increases as a result of the descent of the projectile. This effect is incorporated into our model to correctly predict the cavity geometry.

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