scholarly journals Ion-Specific Effects on Equilibrium Adsorption Layers of Ionic Surfactants

2018 ◽  
Vol 2 (2) ◽  
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 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. 

scholarly journals Ion-specific effects on equilibrium adsorption layers of ionic surfactants

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.

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

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.

Statistics of rupture in relation to the stability of thin liquid films with different size

2011 ◽  
Vol 382 (1-3) ◽  
pp. 174-180 ◽  
Author(s):  
Theodor D. Gurkov ◽  
Jana K. Angarska ◽  
Krassimir D. Tachev ◽  
Wolfgang Gaschler
Keyword(s):  
Liquid Films ◽  
Thin Liquid Films ◽  
The Stability

A Study of Thin Liquid Films as Related to the Stability of Crude Oil Emulsions

2001 ◽  
Vol 238 (1) ◽  
pp. 177-182 ◽  
Author(s):  
Hongbo Fang ◽  
Lu Zhang ◽  
Lan Luo ◽  
Sui Zhao ◽  
Jingyi An ◽  
...  
Keyword(s):  
Crude Oil ◽  
Liquid Films ◽  
Thin Liquid Films ◽  
Oil Emulsions ◽  
The Stability

Role of Surface Forces in the Stability of Evaporating Thin Liquid Films That Contain Surfactant Micelles

1998 ◽  
Vol 198 (2) ◽  
pp. 224-240 ◽  
Author(s):  
Theodor Gurkov ◽  
Krassimir Danov ◽  
Norbert Alleborn ◽  
Hans Raszillier ◽  
Franz Durst
Keyword(s):  
Liquid Films ◽  
Surface Forces ◽  
Thin Liquid Films ◽  
Surfactant Micelles ◽  
The Stability

scholarly journals ANALYSIS OF INTERMOLECULAR INTERACTIONS IN MIXED ADSORPTION LAYERS OF SURFACTANTS

2019 ◽  
Vol 85 (5) ◽  
pp. 69-74
Author(s):  
Olha Kochkodan ◽  
Nadiya Antraptseva ◽  
Roman Zhyla
Keyword(s):  
Adsorption Layer ◽  
Chemical Nature ◽  
Binary Solution ◽  
Molar Fraction ◽  
Graphitized Carbon Black ◽  
Ionic Surfactant ◽  
Surface Active ◽  
Triton X ◽  
Adsorption Layers ◽  
Mixed Systems

The adsorption of the surfactants mixtures of different chemical nature such as Triton X-100 and sodium hexadecyl sulfate at the surface of graphitized carbon black was studied. Using the model of phase separation (the Rubi–Rosen approach), the composition of the mixed adsorption layers and parameters of interaction between the surfactant molecules in the adsorption layers were calculated. It was found that mixed adsorption layers are enriched with molecules of the non-ionic surfactant Triton X-100. The purpose of the work was to study the adsorption of binary mixtures of surfactants of various chemical nature on the surface of non-porous hydrophobic carbon sorbent at different SAS ratio in mixtures. The results of calculations show that the composition of the adsorption layer on the surface of the GC is significantly different from the ratio of surfactants in the solution. The value of the parameter χ indicates that the mixed adsorption layer on the surface of the GC is enriched with non-ionic surfactant molecules, even with a small its content in the solution (αTХ-100 = 0,2). With an increase in the ТХ-100 molar fraction in the binary solution from 0,2 to 0,8 its share in the adsorption layer increases in approximately 1.5 times. Negative values of the interaction parameters βs indicate excessive attraction of the molecules and ions of the mixture components in the mixed adsorption layers. An increase in the absolute value of the parameter βs with an increase in αTХ-100 in the solution characterizes the enhancement of the interactions between the components in the adsorption layer. Thus, in the course of experiments carried out for mixed systems of SHDS-ТХ-100, the existence of a synergistic effect in relation to an increase in the adsorption of surfactants on the GC surface was established. It is found that mixed adsorption layers are enriched with molecules of the non-ionic surface  active  substance  of  the  triton  X-100.

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