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See detailFoam imbibition in microgravity - An experimental study
Caps, Hervé ULg; Decauwer, H.; Chevalier, M. L. et al

in European Physical Journal B -- Condensed Matter (2003), 33(1), 115-119

We report an experimental study of aqueous foam imbibition in microgravity with strict mass conservation. The foam is in a Hele-Shaw cell. The bubble edge width l is measured by image analysis. The ... [more ▼]

We report an experimental study of aqueous foam imbibition in microgravity with strict mass conservation. The foam is in a Hele-Shaw cell. The bubble edge width l is measured by image analysis. The penetration of the liquid in the foam, the foam imbibition, the foam inflation, and the rigidity loss are shown all to obey strict diffusion processes. The motion of bubbles needed for the foam inflation is a slow two-dimensional process with respect to the one-dimensional capillary rise of liquid. The foam is found to imbibes faster than it inflates. [less ▲]

Detailed reference viewed: 21 (3 ULg)
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See detailFoam-like evolution in polycrystalline systems following successive 'melt and growth' cycles
Vandewalle, Nicolas ULg; Delisse, B.; Ausloos, Marcel ULg et al

in Philosophical Magazine B-Physics of condensed matter statistical mechanics electronic optical and magnetic properties (1998), 78(4), 397-408

A stochastic model of multigrain growth which allows for successive melting-growth cycles is investigated on a square lattice. Two fundamental constraints are introduced: (i) the melted mass amplitude and ... [more ▼]

A stochastic model of multigrain growth which allows for successive melting-growth cycles is investigated on a square lattice. Two fundamental constraints are introduced: (i) the melted mass amplitude and (ii) the number of cycles guide the process. The evolution of the microstructure is found to be quite similar to foam systems, i.e. topological rearrangements are observed together with the increase of the-mean grain area. A drastic crossover between two types of growth regimes is found as a function of the amplitude of the melting-growth cycles. This allows one to envisage the existence of optimal conditions for polycrystal processing. [less ▲]

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See detailFoamability and Foam Stability of Male and Female Date Palm Sap (Phoenix dactylifera L.) During the Collection Period
Makhlouf-gafsi, Ines; Mokni-ghribi, Abir; Bchir, Brahim et al

in Food Biophysics (2015)

This work aimed to study the influence of date palm sex on the surface properties of date palm sap (DPS) (Phoenix dactylifera L.) during the collection period. The behavior at the interface and foaming ... [more ▼]

This work aimed to study the influence of date palm sex on the surface properties of date palm sap (DPS) (Phoenix dactylifera L.) during the collection period. The behavior at the interface and foaming properties were evaluated via equilibrium surface tension (drop volume) and bubbling method, respectively. Unlike male sap, the female sap was unable to produce foam due to its low rate of adsorption, low average hydrophobicity values, and low bulk viscosity values throughout the collection period. For male sap, there are significant differences (p<0.05) on foaming properties throughout the collection period. In fact, the last 3 weeks of sap collection were characterized by a decrease pace of surface tension which explains the enhancement of both foam capacity and stability. The last week of collection period present the best foam power (0.9). To explain these differences, the interactions of several factors and their affects on foaming properties were examined. Results showed a positive correlation between foam capacity and average hydrophobicity values. In the other hand, foam stability exhibits a positive correlation with the increase of protein concentration and bulk viscosity. [less ▲]

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See detailFoamability and structure analysis of foams in Hele-Shaw cell
Caps, Hervé ULg; Vandewalle, Nicolas ULg; Broze, Guy ULg et al

in Applied Physics Letters (2007), 90(21),

The authors have generated two-dimensional foams by imposing an intermittent drainage in a Hele-Shaw cell partially filled with a detergent/water mixture. The foam generation associated with this process ... [more ▼]

The authors have generated two-dimensional foams by imposing an intermittent drainage in a Hele-Shaw cell partially filled with a detergent/water mixture. The foam generation associated with this process is reproducible and depends on the surfactant molecules composing the solution. A kinetic model can be proposed for the foam evolution. The structure of the foam is also investigated: the average bubble side number and correlation functions are measured. Distinguishable behaviors are observed for different surfactant molecules. This way of producing a foam is thus adequate for applied foam structure characterizations and fundamental studies. (c) 2007 American Institute of Physics. [less ▲]

Detailed reference viewed: 26 (4 ULg)
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See detailFoamed nanocomposites for EMI shielding applications
Molenberg, Isabel; Huynen, Isabelle; Baudouin, Anne-Christine et al

in Mukherjee, Moumita (Ed.) Advanced Microwave and Milimeter Wave Technologies Semiconductor Devices Circuits and Systems (2010)

Detailed reference viewed: 49 (3 ULg)
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See detailFOAMING CAPACITY FOR PROTEIN ISOLATES - ELECTROKINETICAL PROPERTIES OF PROTEIN DISPERSIONS
BASTIAENS, A.; Paquot, Michel ULg; MARBAISE, M. et al

in Sciences des Aliments (1990), 10(4), 773-783

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See detailFoaming dynamics in Hele-Shaw cells
Caps, Hervé ULg; Vandewalle, Nicolas ULg; Broze, Guy ULg

in Physical Review E (2006), 73(6, Pt 2), 65301

We have studied foaming dynamics in Hele-Shaw cells partially filled with a soap and water mixture. A series of upside-down flips produces an intermittent wetting of the cell and leads to foam formation ... [more ▼]

We have studied foaming dynamics in Hele-Shaw cells partially filled with a soap and water mixture. A series of upside-down flips produces an intermittent wetting of the cell and leads to foam formation. As a function of the number of flips, an increasing number of bubbles composes the foam, until saturation is observed. Statistical analysis shows that the bubble size follows a Gamma distribution. Contrary to common belief, this foaming dynamics by "shaking" creates homogeneous foam, even though the system may pass through transient heterogeneous configurations. A mechanistic interpretation is proposed and included into a theoretical model. [less ▲]

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See detailFoaming properties of a natural cyclic lipoheptapeptide belonging to a special class of amphiphilic molecules
Razafindralambo, Hary ULg; Paquot, Michel ULg; Baniel, A. et al

in Food Hydrocolloids (1997), 11(1), 59-62

The foaming properties of surfactin, a natural cyclic lipoheptapeptide from Bacillus subtilis, were investigated in comparison and in association with those of bovine serum albumin (BSA). An apparatus ... [more ▼]

The foaming properties of surfactin, a natural cyclic lipoheptapeptide from Bacillus subtilis, were investigated in comparison and in association with those of bovine serum albumin (BSA). An apparatus combining bubbling, optical and conductimetric methods was used to study continuously foam formation and stability in terms of the quantity and density of foam. The increase in surfactin concentration from 0.05 to 0.2 mg/ml had little effect on its foaming capacity, measured by the bubbling time to produce the required foam volume, but improved the foam maximum density significantly. Surfactin produced foam with higher maximum density and stability, and forms more regular and smaller bubbles than BSA. In addition, a synergistic effect was observed on the stability of liquid in foam prepared with a mixture of 50:50 surfactin/BSA. The liquid half-life of BSA foam was enhanced up to 40% when surfactin was added to the solution. [less ▲]

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See detailFoaming properties of lipopeptides produced by Bacillus subtilis: effect of lipid and peptide structural attributes
Razafindralambo, Hary ULg; Popineau, Yves; Deleu, Magali ULg et al

in Journal of Agricultural and Food Chemistry (1998), 46(3), 911-916

To study the effect of lipid and peptide structural attributes of Bacillus subtilis lipopeptides on their foaming properties, the formation, stability, and appearance of foams prepared with surfactins ... [more ▼]

To study the effect of lipid and peptide structural attributes of Bacillus subtilis lipopeptides on their foaming properties, the formation, stability, and appearance of foams prepared with surfactins (C13 C15) and iturins A (C14 C17) were characterized. The density and stability of lipopeptide foams depend on both the alkyl chain hydrophobic character and peptide molecular intrinsic properties. A lipidic chain length of 14 carbon atoms provides lipopeptides with the best foaming properties in terms of foam density and liquid stability in foams. Increases in alkyl chain length above 15 carbon atoms result in a drastic decrease of iturin A foam density. With the same alkyl chain, surfactin produces denser foam whereas iturin A exhibits better foaming stability. These results demonstrate the importance of the peptide structural attributes of B. subtilis on their foaming properties. [less ▲]

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See detailFoaming Properties Of Surfactin, A Lipopeptide Biosurfactant From Bacillus Subtilis
Razafindralambo, Hary ULg; Paquot, Michel ULg; Baniel, Alain et al

in Journal of the American Oil Chemists' Society (1996), 73(1), 149-151

Foaming properties of surfactin were investigated and compared to those of sodium dodecyl sulfate (SDS) and bovine serum albumin (BSA). Foams were formed by a bubbling technique. Evolution of the foam ... [more ▼]

Foaming properties of surfactin were investigated and compared to those of sodium dodecyl sulfate (SDS) and bovine serum albumin (BSA). Foams were formed by a bubbling technique. Evolution of the foam volume and the liquid in the foam was monitored with optical and conductimetric methods to characterize foam formation and stability. Excellent foaming properties of surfactin were shown by its higher ability to form and stabilize the foam at a concentration as low as 0.05 mg/mL, in comparison with SDS and BSA. Surfactin produced a foam with intermediate maximum density and stabilized the liquid in foam, as well as BSA. [less ▲]

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See detailFoams in a rotating drum: An analogy with granular materials
Bronfort, Ariane ULg; Caps, Hervé ULg

in Colloids and Surfaces A : Physicochemical and Engineering Aspects (2015)

Rotating drums are usually used to study the flowing properties of granular materials. Here, we report experiments performed in a drum made of a circular Hele-Shaw cell filled with a monodisperse foam and ... [more ▼]

Rotating drums are usually used to study the flowing properties of granular materials. Here, we report experiments performed in a drum made of a circular Hele-Shaw cell filled with a monodisperse foam and its surfactant solution. The cell is placed vertically and rotated around its center with an angular velocity ω. The rotation of the cell modifies the foam properties and therefore influences its response to the external strain. The observed foam behavior is similar to granular media in several aspects. Using tools developed for granular materials, we characterize the foam evolution in terms of a dimensionless viscous number I f and we compare the foam rheology to the theory developed for the immersed granular material rheology. © 2015 Elsevier B.V. [less ▲]

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See detailFoams of polycaprolactone/MWNT nanocomposites for efficient EMI reduction
Thomassin, Jean-Michel ULg; Pagnoulle, Christophe; Bednarz, Lukasz et al

in Journal of Materials Chemistry (2008), 18(7), 792-796

Nanocomposites of polycaprolactone (PCL) filled with multi-walled carbon nanotubes (MWNTs) were foamed by supercritical CO2 in order to prepare materials with reduced electromagnetic interference (EMI ... [more ▼]

Nanocomposites of polycaprolactone (PCL) filled with multi-walled carbon nanotubes (MWNTs) were foamed by supercritical CO2 in order to prepare materials with reduced electromagnetic interference (EMI). Two mixing techniques were used, i.e., melt blending and co-precipitation. Shielding efficiency as high as 60 to 80 dB together with a low reflectivity was observed at a very low vol% of MWNTs (0.25 vol%). The reflectivity of the nanocomposites was advantageously decreased upon foaming. The uniformity of the open-cell structure was assessed by scanning electron microscopy. These foamed PCL/MWNT nanocomposites are very promising EMI shielding materials because their performances result from absorption at low filler content and not from reflection at relatively high filler content as was previously the case. [less ▲]

Detailed reference viewed: 151 (12 ULg)
See detailFoams of polycaprolactone/MWNT nanocomposites for efficient EMI shielding
Thomassin, Jean-Michel ULg; Pagnoulle, Christophe; Bednarz, Lukasz et al

Conference (2008, September 09)

Detailed reference viewed: 25 (3 ULg)
See detailFoams of polycaprolactone/MWNT nanocomposites for efficient EMI shielding
Thomassin, Jean-Michel ULg; Kollar, J.; Caldarella, Giuseppe ULg et al

Conference (2007, August 27)

Detailed reference viewed: 30 (2 ULg)
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See detailFoams of polyurethane/MWNT nanocomposites for efficient EMI reduction
Chen, Y. Y.; Urbanczyk, Laetitia ULg; Thomassin, Jean-Michel ULg et al

Poster (2009, September 16)

Detailed reference viewed: 59 (15 ULg)
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See detailFocal cerebral ischemia impairs motivation in a progressive FR schedule of reinforcement in mice
Linden, Jérôme ULg; Plumier, Jean-Christophe ULg; Fassotte, Ludivine et al

in Behavioural Brain Research (2015), 279

Detailed reference viewed: 37 (3 ULg)