Aqueous foam slip and shear regimes determined by rheometry and multiple light scattering

Marze, Sébastien; Langévin, D.; Saint‐Jalmes, Arnaud

doi:10.1122/1.2952510

Cited by 67 publications

(108 citation statements)

References 50 publications

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“…For foams and concentrated emulsions with F > F CP , values of n between 0.2 and 0.5 are usually reported. 9,17,23,25 The interpretation of the values of the consistency k is more complex, because the dimension of k is Pa.s n and, therefore, it depends on the specific value of n, see eqn (1). The simplest case is n ¼ 1, when k coincides with the common viscosity, as defined for Newtonian fluids.…”

Section: Inside-foam Viscous Frictionmentioning

confidence: 99%

“…In parallel, the effects of surfactants on dynamic phenomena in foams were studied by several other research groups. 25,[47][48][49][50] In the current review we summarise the progress achieved so far in these studies. Comparison with the results of the various research groups is made, and some open questions, deserving further investigation, are discussed.…”

Section: -1432mentioning

confidence: 99%

“…In fact, we found that the same master line, representing eqn (5) (1) Systems in which the power-law index n z 1/2. 9,16,17,[23][24][25]54,55 In these systems n varied between 0.42 and 0.5 (centred at n z 0.47), depending on the specific surfactant and glycerol concentration in the foaming solution.…”

Section: Inside-foam Viscous Frictionmentioning

confidence: 99%

“…[23][24][25] Examples for such surfactants are the sodium and potassium laurates, myristates, palmitates, cocoylglycinates, etc. For these systems, the value of n is around 0.2 (at m z 1 mPa.s) and the measured viscous stress does not scale with solution viscosity, see Fig.…”

Section: 25mentioning

confidence: 99%

“…17,[22][23][24][25] These specific effects are in most cases related to the type of foam stabilizers used (surfactants, polymers, particles). Despite the importance of this specificity for the ubiquitous practical applications of foams, it often creates serious problems in the scientific interpretation of the experimental data, in the comparison of the results obtained by different groups, and in the generalization of the obtained results and conclusions to other related systems.…”

Section: Konstantin Golemanovmentioning

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: Inside-foam Viscous Frictionmentioning

confidence: 99%

Section: -1432mentioning

confidence: 99%

Section: Inside-foam Viscous Frictionmentioning

confidence: 99%

Section: 25mentioning

confidence: 99%

Section: Konstantin Golemanovmentioning

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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Foam Rheology

Denkov

Höhler²,

Cohen-Addad³

2012

Foam Engineering

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Foam‐in‐vein: A review of rheological properties and characterization methods for optimization of sclerosing foams

et al. 2020

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Varicose veins are chronic venous defects that affect >20% of the population in developed countries. Among potential treatments, sclerotherapy is one of the most commonly used. It involves endovenous injection of a surfactant solution (or foam) in varicose veins, inducing damage to the endothelial layer and subsequent vessel sclerosis. Treatments have proven to be effective in the short-term, however recurrence is reported at rates of up to 64% 5-year post-treatment. Thus, once diagnosed with varicosities there is a high probability of a permanently reduced quality of life. Recently, foam sclerotherapy has become increasingly popular over its liquid counterpart, since foams can treat larger and longer varicosities more effectively, they can be imaged using ultrasound, and require lower amounts of sclerosing agent. In order to minimize recurrence rates however, an investigation of current treatment methods should lead to more effective and long-lasting effects. The literature is populated with studies aimed at characterizing the fundamental physics of aqueous foams; nevertheless, there is a significant need for appropriate product development platforms. Despite successfully capturing the microstructural evolution of aqueous foams, the complexity of current models renders them inadequate for pharmaceutical development. This review article will focus on the physics of foams and the attempts at optimizing them for sclerotherapy. This takes the form of a discussion of the most recent numerical and experimental models, as well as an overview of clinically relevant parameters. This holistic approach could contribute to better foam characterization methods that patients may eventually derive long term benefit from.

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Aqueous foam slip and shear regimes determined by rheometry and multiple light scattering

Cited by 67 publications

References 50 publications

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

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

Foam Rheology

Foam‐in‐vein: A review of rheological properties and characterization methods for optimization of sclerosing foams

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