scispace - formally typeset
Search or ask a question
Journal ArticleDOI

A Generalized View of Foam Drainage: Experiment and Theory

30 Jun 2000-Langmuir (American Chemical Society)-Vol. 16, Iss: 15, pp 6327-6341
TL;DR: In this paper, a new experimental method is presented using fluorescein dye to determine the spatial and temporal variations of the liquid volume fraction in aqueous foams This method was used for quantitative studies of liquid redistribution (drainage) in three types of experiments: forced, free, and pulsed drainage Characteristic quantities, such as the drainage velocity, show power-law dependences on experimental parameters that are inconsistent with traditional foam drainage models based on Poiseuille-type flow in the liquid-carrying channels (Plateau borders) of the foam.
Abstract: A new experimental method is presented using fluorescein dye to determine the spatial and temporal variations of the liquid volume fraction in aqueous foams This method is used for quantitative studies of liquid redistribution (drainage) in three types of experiments: forced, free, and pulsed drainage Characteristic quantities, such as the drainage velocity, show power-law dependences on experimental parameters that are inconsistent with traditional foam drainage models based on Poiseuille-type flow in the liquid-carrying channels (Plateau borders) of the foam To obtain a theoretical description, the foam drainage equation is generalized using an energy argument which accounts for viscous dissipation in both the channels and the nodes (or vertices, which are the junctions of four channels) of the liquid network Good agreement with results for all three types of drainage experiments is found when using this new model in the limit where the dissipation is dominated by the nodes
Citations
More filters
01 Jan 2009
TL;DR: In this article, a long series of experiments proving that the physical processes along fluid interfaces can be exploited for creating unusual fluidic objects was presented, such as liquid onions and mayonnaise droplets.
Abstract: Keywords: Droplets Bubbles Microfluidics Encapsulation Emulsion a b s t r a c t In this paper, we emphasize our long series of experiments proving that the physical processes along fluid interfaces can be exploited for creating unusual fluidic objects. We report for the first time a couple of new fluidic objects so-called “liquid onions” and “mayonnaise” droplets. The study starts from the observation of antibubbles, exhibiting unstable liquid‐air‐liquid interfaces. We show that the lifetime of such a system has the same origin as floating/coalescing droplets on liquid surfaces. By analyzing such behaviours, we created droplets bouncing on a liquid bath. The methods and physical phenomena collected in this paper provide a basis for the development of a discrete microfluidics. Open questions are underlined, experimental challenges and future applications are proposed.

540 citations

Journal ArticleDOI
TL;DR: This review will focus on integrating the colloidal/polymer and biological aspects of protein functionality using foams and gels to illustrate colloidal-polymer aspects and bioactive peptides and allergenicity to demonstrate biological function.

329 citations

Journal ArticleDOI
TL;DR: This review covers recent advances in the study of foam drainage and coarsening, focusing especially on the effective role of the foam chemical components on those aging processes, and summarizes how the surfactant, the liquid bulk properties, and the gas modify or not the drainage andCoarsening features.
Abstract: This review covers recent advances in the study of foam drainage and coarsening, focusing especially on the effective role of the foam chemical components on those aging processes. The determination of the relevant parameters controlling foam drainage and coarsening today remains a major issue: are the physical parameters (like bubble size and liquid fraction) sufficient to define a foam and to predict its evolution, or do the chemical components also matter? And if these foam components are important, one has to determine by which mechanisms, and which microscopic parameters involved in these mechanisms are eventually crucial. I report here recent experimental results, shedding light on these issues. It allows us to summarize how the surfactant, the liquid bulk properties, and the gas modify or not the drainage and coarsening features. The coupling between drainage and coarsening is also discussed, as well as the role of the experimental conditions (sample height, shape or foam uniformity).

319 citations

Journal ArticleDOI
TL;DR: A review of experiments, numerical simulations and theoretical models concerning foam rheology can be found in this paper, where the authors briefly recall the basic physics and physicochemistry of foams.
Abstract: Liquid foams can behave like solids or liquids, depending on the applied stress and on the experimental timescale. Understanding the origin of this complex rheology which gives rise to many applications and which resembles that of many other forms of soft condensed matter made of closely packed soft units requires challenging theoretical questions to be solved. We briefly recall the basic physics and physicochemistry of foams and review the experiments, numerical simulations and theoretical models concerning foam rheology published in recent years.

258 citations

Journal ArticleDOI
TL;DR: In this paper, a study of foamability and foam stability in the absence and in the presence of alkane-type oils for various surfactants was conducted, and the results for foam stability were discussed in terms of the classical entering/spreading coefficient, oil solubilization effect and stability of pseudoemulsion film.

245 citations

References
More filters
Book
01 Jan 1960
TL;DR: In this paper, the authors discuss the nature and properties of liquid interfaces, including the formation of a new phase, nucleation and crystal growth, and the contact angle of surfaces of solids.
Abstract: Capillarity. The Nature and Thermodynamics of Liquid Interfaces. Surface Films on Liquid Substrates. Electrical Aspects of Surface Chemistry. Long--Range Forces. Surfaces of Solids. Surfaces of Solids: Microscopy and Spectroscopy. The Formation of a New Phase--Nucleation and Crystal Growth. The Solid--Liquid Interface--Contact Angle. The Solid--Liquid Interface--Adsorption from Solution. Frication, Lubrication, and Adhesion. Wetting, Flotation, and Detergency. Emulsions, Foams, and Aerosols. Macromolecular Surface Films, Charged Films, and Langmuir--Blodgett Layers. The Solid--Gas Interface--General Considerations. Adsorption of Gases and Vapors on Solids. Chemisorption and Catalysis. Index.

10,790 citations

Journal ArticleDOI
TL;DR: In this paper, the problem of slow flow through a periodic array of spheres was formulated as a set of two-dimensional integral equations for the unknown surface stress vector, thus lowering the dimension of the problem.
Abstract: We treat the problem of slow flow through a periodic array of spheres Our interest is in the drag force exerted on the array, and hence the permeability of such arrays It is shown to be convenient to formulate the problem as a set of two-dimensional integral equations for the unknown surface stress vector, thus lowering the dimension of the problem This set is solved numerically to obtain the drag as a function of particle concentration and packing characteristics Results are given over the full concentration range for simple cubic, body-centred cubic and face-centred cubic arrays and these agree well with previous limited experimental, asymptotic and numerical results

464 citations

Journal ArticleDOI
TL;DR: In this article, the division of space with minimum partitional area is discussed, and the authors propose a solution to the problem of partitioning space with a minimum number of partsitional areas.
Abstract: (1887). LXIII. On the division of space with minimum partitional area. The London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science: Vol. 24, No. 151, pp. 503-514.

432 citations

Book
01 Jan 1978

366 citations

Journal ArticleDOI
TL;DR: In this paper, the authors review the history and recent development of this theory, analysing various exact and approximate solutions and relating them to each other, and propose a nonlinear partial differential equation for the foam density as a function of time and vertical position.
Abstract: The drainage of liquid in a foam may be described in terms of a nonlinear partial differential equation for the foam density as a function of time and vertical position. We review the history and recent development of this theory, analysing various exact and approximate solutions and relating them to each other.

283 citations