Aqueous Foams: A Field of Investigation at the Frontier Between Chemistry and Physics

Langévin, D.

doi:10.1002/cphc.200700675

Cited by 106 publications

(116 citation statements)

References 98 publications

(79 reference statements)

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“…34,38,[42][43][44][45] Obviously, the dynamic properties of bubble surfaces could be important for all dynamic phenomena in foams, including foam flow, foam expansion in the process of extrusion (e.g., in cosmetic products, such as shaving and hair foams; and during production of plastic foams from liquid precursors), Ostwald ripening (important for long-term stability of food and cosmetic products), dispersion of particles in the network of Plateau channels (relevant to froth flotation and waste water treatment), and many others. [2][3][4][5] However, the studies focused on the role of surfactant type on these phenomena were very limited until recently.…”

Section: -1432mentioning

confidence: 99%

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The role of surfactant type and bubble surface mobility in foam rheology

et al. 2009

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This paper is an overview of our recent understanding of the effects of surfactant type and bubble surface mobility on foam rheological properties. The focus is on the viscous friction between bubbles in steadily sheared foams, as well as between bubbles and confining solid wall. Large set of experimental results is reviewed to demonstrate that two qualitatively different classes of surfactants can be clearly distinguished. The first class is represented by the typical synthetic surfactants (such as sodium dodecylsulfate) which are characterised with low surface modulus and fast relaxation of the surface tension after a rapid change of surface area. In contrast, the second class of surfactants exhibits high surface modulus and relatively slow relaxation of the surface tension. Typical examples for this class are the sodium and potassium salts of fatty acids (alkylcarboxylic acids), such as lauric and myristic acids. With respect to foam rheology, the second class of surfactants leads to significantly higher viscous stress and to different scaling laws of the shear stress vs. shear rate in flowing foams. The reasons for these differences are discussed from the viewpoint of the mechanisms of viscous dissipation of energy in sheared foams and the respective theoretical models. The process of bubble breakup in sheared foams (determining the final bubble-size distribution after foam shearing) is also discussed, because the experimental results and their analysis show that this phenomenon is controlled by foam rheological properties.

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Section: -1432mentioning

confidence: 99%

“…This process leads to a remarkable transformation of two Newtonian fluids (air and water) into a complex fluid with nontrivial visco-elastoplastic rheological properties, [1][2][3][4][5][6] see Fig. 1.…”

Section: Introductionmentioning

confidence: 99%

The role of surfactant type and bubble surface mobility in foam rheology

et al. 2009

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“…Obviously, the dynamic properties of bubble surfaces could be important for all dynamic phenomena in foams, including foam flow, foam expansion in the process of extrusion, Ostwald ripening, dispersion of particles in the network of Plateau channels, and many others [12][13][14][15] .…”

Section: Introductionmentioning

confidence: 99%

Effect of organic acid on lauroamide propyl betaine surface dilatational modulus and foam performance in a porous medium

Wang

Ge²,

Zhang

et al. 2017

Journal of Dispersion Science and Technology

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The purpose of this work was to study the effect of surface tension and surface dilatational modulus on foam performance in high salinity water in a porous medium. In order to clarify the role of the surface dilatational property in foam flow in a porous medium, three systems were established: a system with low surface dilatational modulus and high surface tension, a system with low surface dilatational modulus and low surface tension, and a system with high surface dilatational modulus and low surface tension. Measurement of dilatational modulus and surface tension showed that lauroamide propyl betaine (LAB) could not reduce surface tension and that surface dilatational modulus was low. The addition of lauric acid (LCOOH) to LAB could not achieve high surface dilatational modulus, however, could reach lower surface tension. The addition of myristic acid (MCOOH) to LAB could achieve high surface dilatational modulus and lower surface tension. Unlike the other two systems, the results of a dilatational modulus comprised of a mixture of MCOOH and LAB was not a constant, as demonstrated by varied surface area deformation outcomes. With the increase of deformation, surface dilatational modulus decreased. Results of foam flow tests showed that among the two lower surface dilatational Downloaded by [Nanyang Technological University] at 05:22 15 June 2016 2 modulus systems, LAB foam had higher flow resistance regardless of flow rate. Among the two systems of similar lower surface tension, the mixture of LAB and MCOOH showed higher flow resistance than the mixture of LAB and LCOOH. However, with the increase of flow rate, pressure differences between the two systems became smaller, which corresponded to the decrease of surface dilatational modulus with an increase of deformation.

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“…There are quite a few activities dedicated to the improvement of knowledge about mechanisms controlling the formation and stability of liquid disperse systems [12]. During the recent years, the ESA project FASES, which stands for "Fundamental and Applied Studies of Emulsion Stability", using the module FAST (Facility for Adsorption and Surface Tension) and its refined version FASTER (Facility for Adsorption and Surface TEnsion Research) [30].…”

mentioning

confidence: 99%

“…A top down approach brings us to the basis of these systems, the corresponding adsorption layers around the bubbles and drops in foams and emulsions. The philosophy of this approach is to learn the most important properties of these adsorption layers and find correlations to the behaviour of liquid films and the final foams and emulsions [10][11][12][13]. It seems rather easy to comprehend that the formation of a foam (foamability) or an emulsion depends directly on the rate of adsorption of surfactants at the interface [14,15].…”

mentioning

confidence: 99%