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soluble surfactant spreading

with Isabelle Cantat (IPR), Matthieu Roché (MSC Paris), I. Griffiths (Oxford) and Howard A. Stone (Princeton University).

how far soluble surfactants spread on water ? and how the amphiphilicity sets the Marangoni hydrodynamics ?

Phys.Rev. Lett., 112, 208302 (2014).
pdf version of a first paper here

Phys.Rev.E, 93, 013107 (2016).
pdf version of a second paper here

And go to this page to find articles in the press about this work, and a nice movie on the INP website.

from thermoresponsive supramolecular assemblies to rheology

In collaboration with A.L. Fameau, INRA Nantes

Investigating the links between microscopic structures and macroscopic dynamics: tubular or micellar mesoscopic organisation of fatty acids in bulk control both the macroscopic bulk and interfacial rheology. Moreover, the non-trivial thermoresponsivity of the molecular system provide original and widely temperature-tunable bulk and interfacial viscoelasticity.

Soft Matter, 2014, 10 (20), 3622 - 3632.

pdf version of the paper here

aqueous foam coiling

Highly viscous fluids, like honey, make coils when falling on a solid board... elastic ropes also make coils... what about the coiling of a viscoelastic fluid? We investigate the coiling of aqueous foam column, and study how it depends on the foam intrinsic properties (liquid fraction, bubble size, chemical formulation) as well as on the foam column diameter and its falling height.

foam acoustics: ultrasound propagation

In collaboration with V. Leroy at MSC - Paris.

Here, we investigated the velocity and the adsorption of various ultrasonic signals (40kHz) propagating through controlled foams. Surprinsingly, all our results evidence the existence of a resonance effect.

here is a first paper : “Propagation of ultrasound in aqueous foams: bubble size dependence and resonance effects” I. BenSalem, R.M. Guillermic, C. Sample, V. Leroy, A. Saint-Jalmes, B. Dollet, Soft Matter, 2013, 9, 1194
pdf version of the paper here

And a second paper on these issues : "Sound propagation in liquid foams: Unraveling the balance between physical and chemical parameters" Juliette Pierre, Brice Giraudet, Patrick Chasle, Benjamin Dollet, and Arnaud Saint-Jalmes PHYSICAL REVIEW E 91, 042311 (2015)
pdf version of the paper here

foam acoustics: light scattering for monitoring sound propagation

In collaboration with Jerome Crassous and Benjamin Dollet at IPR
Foams have very unusual acoustic properties. The propagation of sound inside a foam remains poorly understood.
We first studied "dancing foams" : we measured the displacement induced by acoustic inside a foam, by using an optical technique (diffusing wave spectroscopy).

“Investigating acoustic-induced deformations in a foam using multiple light scattering” M. Erpelding, R.M. Guillermic, B. Dollet, A. Saint-Jalmes, J. Crassous Phys. Rev. E 82, (021409) (2010)
pdf version of a first paper here

an additional poster in pdf version here

We also developped a new approach to monitor the features of an acoustic wave propagating into a foam.
"Synchronized Diffusive Wave Spectroscopy: Principle and Application to Sound Propagation in Aqueous Foams"
jerome Crassous,Patrick Chasle, Juliette Pierre, Arnaud Saint-Jalmes, and Benjamin Dollet, PHYSICAL REVIEW E, 93, 032611 (2016)
pdf version of the paper here

Casein Microgels from Cross-Linking of Casein Micelles by Genipin

In collaboration with F. Gaucheron at STLO-INRA Rennes.

By adding Genipin to solutions of casein micelles, we were able to create a new colloidal object, and studied its resistance to destabilizing effects.

Langmuir, DOI: 10.1021/la502274b (2014)

pdf version of the paper here

Blast wave absorption in liquid foams

In collaboration with M. Monloubou, I. Cantat and B. Dollet at IPR.

blast wave absorption by liquid foams is especially efficient, and bubble size or liquid fraction optimization is an important challenge in this context.

"Influence of bubble size and thermal dissipation on compressive wave attenuation in liquid foams", EPL, 112 (2015) 34001.

pdf version of a first paper here

With a second paper submitted to 'Soft Matter': "Blast wave attenuation in liquid foams: role of gas and evidence of an optimal bubble size", by M. Monloubou, M.A.Bruning, A. Saint-Jalmes, B. Dollet and and I. Cantat

Smart Non-Aqueous Foams from Oleogel Based on Lipids

In collaboration with Anne-Laure Fameau (INRA Rennes) and O. Velev (Norht Caroline State Univ.).

we introduced a novel approach to produce oil foams made from an oleogel based on fatty alcohol platelets dispersed in sunflower oil. The produced foams are stable for months, while the collapse of the foams could be induced quickly upon heating due to the melting of the crystal particles surrounding the bubbles.

Langmuir, 31, 13501-13510 (2015).

pdf version of the paper here

instabilities in a thermoresponsive polymer solution

Using solution of Poly-nipam in 2D cells, we investigate thermoconvective instabilities, ...but with a polymeric solution which properties change drastically at a well-defined temperature.

inversing drainage in foams and thin-films using light

In collaboration with E. Chevallier, F. Lequeux and C. Monteux, ESPCI, Paris ; and I. Cantat, Rennes.

Using photoresponsive surfactants, we are able to trigger flows, by a UV illumination, opposing the usual gravitational drainage: in a vertical thin liquid film, the fluid can refill the film (green arrow) once under UV. Similar light-induced pumping effects occur alo in 3D foams, at the scale of the liquid channels (Plateau borders).

Soft Matter, DOI: 10.1039/c3sm50258a (2013)

pdf version of the paper here

actuation of soft gels (or "living sushis")

In collaboration with G. Maurdev (CSIRO, Australia), and F. Gauffre (ISCR).

large and reversible deformations of soft thermoresponsive gels (based on Poly-nipam) can be induced by temperature-induced local swelling or shrinking.

Some people suggested that these bending gels look like "living sushis". Want some :) ?

droplet motion by chromocapillary effects

Experiments with Damien Baigl and Antoine Diguet at ENS-Paris

How an oil droplet, sitting on top of a liquid pool, can be moved only by light ? And how the direction of the displacement can depend on the wavelength of the light ??

“droplet manipulation by chromocapillary effects”
A. Diguet, R.M. Guillermic, N. Magome, A. Saint-Jalmes, Y. Chen, K. Yoshikawa, D. Baigl
Angewandte Chemie Int. Ed. , 48 (49), 9281 (2009).
pdf version of the paper here

an additional poster in pdf version here

And go to this page to find articles in the press about this work.

Smart Foams: Switching Reversibly between Ultrastable and Unstable Foams

in collaboration with INRA Nantes, CEA Saclay and crpp-Bordeaux

how can one change from an "almost eternal" foam to a highly unstable one ? just raise temperature (...if you have the good surfactant for that !)

« Smart Foams: Switching Reversibly between Ultrastable and Unstable Foams »
Anne-Laure Fameau, Arnaud Saint-Jalmes, Fabrice Cousin, Bérénice Houinsou Houssou, Bruno Novales, Laurence Navailles, Janine Emile, Frédéric Nallet, Cédric Gaillard, François Boué, Jean-Paul Douliez.
Angewandte Chemie, Int. Ed. Volume 123, Issue 36, pages 8414–8419, August 29, 2011

find a poster in pdf version here

And go to this page to find articles in the press about this work.

Oligomeric Surfactant : Tuning Foam Stability by the Surfactant Structure

In collaboration with Martin In at LCVN Montpellier

We investigated the foaming of solutions made of a family of well-controlled molecules : monomer of cationic surfactants, then dimers, trimers and tetramers. The spacer between the head group is also variable between two values (3 or 6 carbons)

“Solutions of Surfactant Oligomers: A Model System for Tuning Foam Stability by the Surfactant Structure » A. Salonen, M. In, J. Emile, A. Saint-Jalmes Soft Matter, 6, 2271(2010)
pdf version of the paper here

an additional poster in pdf version here

internal dynamics of particle-stabilized foams

In collaboration with D. Langevin's group in Orsay

In collaboration with Jerome Crassous at IPR

A previous study - published in Soft matter in 2008 (see the "papers" section) dealt with the outstanding stability of these foams, containing no surfactants, but solely stabilized by silica nanoparticles.
Recently, we investiugated the internal dynamics of these particle-stabilized foams. We showed that two modes co-exist, one linked to the motion of the free particles inside the netweork of liquid channels, and another one linked to the foam structure evolution....

"Two-Modes Dynamics in Dispersed Systems : the Case of Particle-Stabilized foams Studied by Diffusing Wave Spectroscopy." A. Stocco, J. Crassous, A. Salonen., A. Saint-Jalmes, D. Langevin. Physical Chemistry Chemical Physics (2010).
pdf version of the latest paper here

Here comes a second paper on these issues : “probing the dynamics of particles in an aging dispersion with diffusing wave spectroscopy” J. Crassous, A. Saint-Jalmes, Soft Matter, 8, 3683 (2012).
pdf version of the latest paper here

dual gas and oil dispersion in water : production and stability of foamulsion

In collaboration with Aniinna Salonen and LPS Orsay

what do you get when foaming an emulsion ? bubbles and droplets have to co-exist, and possibly make "foamulsions". And it can go from rapidly collapsing foamulsions to ultra-stable ones.

“ foaming emulsion” A. Salonen, W. Drenckhan, E. Rio, A.Saint-Jalmes, D. Langevin, Proceedings du Congrès Mondial de l'Emulsion, Lyon, Vol.3, (2010)

“ dual gas and oil dispersion in water : production and stability of foamulsion” A. Salonen, R. Lhermerout, E. Rio, D. Langevin, A.Saint-Jalmes, Soft Matter (2011)

a poster in pdf version here

pdf version of the latest paper here

laponite-doped foams

what's going on when the foaming fluid itself has its own time-dependent rheology ? or : a glass inside a glass...

“Surfactant Foams Doped with Laponite : Unusual Behaviors Induced by Aging and Confinement” R.M. Guillermic, A. Salonen, J. Emile, A. Saint-Jalmes Soft Matter, DOI: 10.1039/b914923f (2009).

pdf version of the paper here

an additional poster in pdf version here

thermo-responsive interfaces and foams

we recently investigated the interfacial dynamics of interfaces where a thermoresponsive polymer (Poly-NIPAM) is adsorbed. It turns out that the whole viscoelasticity - both in shear and in compression - can be widely tuned by the temperature, within a short range of degrees. Associating these interfaces, can we get responsive foams ? and what is the impact of the addition of a surfactant ? These are some of the issues we have investigated.

“Dynamics of poly-nipam chains in competition with surfactants at liquid interfaces: from thermoresponsive interfacial rheology to foams”, R.M. Guillermic, A. Saint-Jalmes, Soft Matter, 2013, 9, 1344.

pdf version of the paper here

Dry and heated lysozyme at liquid interfaces

In collaboration with S. Beaufils and V. Vié at IPR, and with INRA Rennes

It's amazing how an interface can enhance and reveal tiny tiny biochemical modifications !

“Strong improvement of interfacial properties can result from slight structural modifications of proteins: the case of native and dry-heated lysozyme”

Yann Desfougères, Arnaud Saint-Jalmes, Anniina Salonen, Véronique Vié, Sylvie Beaufils, Stéphane Pezennec, Bernard Desbat, Valérie Lechevalier, and Françoise Nau.

pdf version of the paper here