Equilibrium and Dynamics of Surfactant Adsorption Monolayers and Thin Liquid Films

This review article reports on the effect of the counter-ions on the ionic surfactant adsorption layer and its relation to the stability of foams and emulsions. The adsorption theory of Davies about the ionic surfactant monolayer was revisited and it is shown how to account for the type of the counter-ions. The experimental validation of this theory on thin liquid films was shown as well, thus explaining the effect of Hofmeister. However their effect on foams and emulsions is more complex. Furthermore, it is shown how the counter-ions affect in complex way the stability of foams and emulsions via the surfactant adsorption layer in the light of the newest theory. To elucidate the nature of this effect further investigation is called for.

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Ion-specific effects on equilibrium adsorption layers of ionic surfactants

Applied Chemical Engineering ◽

10.24294/ace.v3i2.603 ◽

2020 ◽

Vol 3 (2) ◽

pp. 53

Author(s):

Stoyan I. Karakashev

Keyword(s):

Experimental Validation ◽

Adsorption Layer ◽

Liquid Films ◽

Thin Liquid Films ◽

Ionic Surfactant ◽

Surfactant Adsorption ◽

Specific Effects ◽

Counter Ions ◽

The Stability ◽

Adsorption Layers

This review article reports the effect of the counter-ions on the ionic surfactant adsorption layer and its relation to the stability of foams and emulsions. The adsorption theory of Davies about the ionic surfactant monolayer was revisited and it is shown how to account for the type of the counter-ions. The experimental validation of this theory on thin liquid films was shown as well, thus explaining the effect of Hofmeister. However, their effect on foams and emulsions is more complex. Furthermore, it is shown how the counter-ions affect in complex way the stability of foams and emulsions via the surfactant adsorption layer in the light of the newest theory. To elucidate the nature of this effect, further investigation is called for.

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Special Discussions of the Faraday Soc. No. 1, 1970: "Thin Liquid Films and Boundary Layers"

Zeitschrift für Physikalische Chemie ◽

10.1524/zpch.1974.88.1-4.223 ◽

1974 ◽

Vol 88 (1-4) ◽

pp. 223-224

Author(s):

G. Peschel

Keyword(s):

Boundary Layers ◽

Liquid Films ◽

Thin Liquid Films

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HEAT TRANSFER IN THIN LIQUID FILMS FLOWING DOWN HEATED INCLINED GROOVED PLATES

Computational Thermal Sciences An International Journal ◽

10.1615/computthermalscien.v2.i5.50 ◽

2010 ◽

Vol 2 (5) ◽

pp. 455-468 ◽

Cited By ~ 2

Author(s):

Hongyi Yu ◽

Karsten Loffler ◽

Tatiana Gambaryan-Roisman ◽

Peter Stephan

Keyword(s):

Heat Transfer ◽

Liquid Films ◽

Thin Liquid Films

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Evaporation-driven solutocapillary flow of thin liquid films over curved substrates

Physical Review Fluids ◽

10.1103/physrevfluids.4.034002 ◽

2019 ◽

Vol 4 (3) ◽

Cited By ~ 7

Author(s):

Mariana Rodríguez-Hakim ◽

Joseph M. Barakat ◽

Xingyi Shi ◽

Eric S. G. Shaqfeh ◽

Gerald G. Fuller

Keyword(s):

Liquid Films ◽

Thin Liquid Films

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Two-layer modeling of thermally induced Bénard convection in thin liquid films: Volume of fluid approach vs thin-film model

AIP Advances ◽

10.1063/5.0047279 ◽

2021 ◽

Vol 11 (4) ◽

pp. 045317

Author(s):

Ali Mohammadtabar ◽

Hadi Nazaripoor ◽

Adham Riad ◽

Arman Hemmati ◽

Mohtada Sadrzadeh

Keyword(s):

Thin Film ◽

Volume Of Fluid ◽

Liquid Films ◽

Thin Liquid Films ◽

Thermally Induced ◽

Film Model ◽

Bénard Convection ◽

Thin Film Model ◽

Benard Convection

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Film Elasticity and Film Stabilization in Firefighting Foam Stabilized by Solid Particles

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.744.346 ◽

2017 ◽

Vol 744 ◽

pp. 346-349

Author(s):

Xiu Juan Li ◽

Rui Song Guo ◽

Min Zhao

Keyword(s):

Life Time ◽

Liquid Films ◽

Thin Liquid Films ◽

Solid Particles ◽

High Concentration ◽

Hydration Effect ◽

Fixed Area ◽

The Stability ◽

Hydration Layers ◽

Hydration Forces

The structure of the thin liquid films determines the stability of foams and emulsions. In this work the bubbles stretched length with different hollow SiO2 particles concentration is measured when the foam has been stilled for different time. The results show that the bubbles stretched length is longer than that of bubbles when the foam is free of hollow SiO2 particles even when the foam has been stilled for 500mins. The bubbles stretched length increases with increasing the concentration of hollow SiO2 particles. A strong hydration effect leaves a large volume of hydration layers on the solid particles surfaces in aqueous solutions. The water in hydration layers can help the film keep a certain thickness. The existence of hydration forces leads that two particles cannot be too close each other. The high concentration surfactant limited in the fixed area helps the film keep good elasticity. Therefore the film has a long life time with compatible thickness and elasticity and the three-phrase foam is upper stable.

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