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Emulsion inversion through a controlled process of multiple emulsions
 
UMR 3299 CEA/CNRS SIS2M-LIONS et UMR7615 PPMD-ESPCI
Thu, May. 12th 2011, 11:00
NIMBE Bât.125, p.157, CEA-Saclay

Stimulable emulsions, which can transit from an oil-in-water (O/W) phase to a water-in-oil (W/O) one are attractive materials for many applications like oil recovery, cosmetic or drug delivery. Such emulsions can be stabilized with emulsifiers like non-ionic surfactants, nanoparticles or polymers.

Recently, we have designed new polymer amphiphilic molecules which are sensitive to pH and temperature. These polymers are able to modify the curvature of the water-toluene interface and promote the phase inversion. They are made of a first block of polystyrene (PS) and a second statistical block of PS and poly-2(dimethyl amino) ethyl methacrylate (PDMAEMA) synthesized by Atom Transfer Radical Polymerization. Composition and length of polymers can be varied with a good precision (PDI<1,3).

At low pH and low temperatures, such polymers stabilize toluene-in-water emulsions while at higher pH and temperatures water-in-toluene emulsions are found. The inversion is directly observable with confocal fluorescent microscopy. Conductivity measurements also show how the emulsion type can be reversibly switched along a temperature scan under stirring.

More recently, we discovered that very stable multiple emulsions are stabilized using a single polymeric surfactant in a definite range of pH dependent on the polymer composition. This is a very interesting phenomenon because usually two types of surfactants are required to form such complex structures. Moreover, we correlated the range of pH where such multiple emulsions appear with the occurrence of a minimum in surface tension between water and toluene phases.


http://www.umr7615.espci.fr/
Contact : Florent MALLOGGI

 

Séminaire LIONS - Informations pratiques

Entrée sur le site du CEA de Saclay pour les séminaires LIONS

 

Afin de pouvoir entrer sur le site du CEA de Saclay veuillez adresser les données personnelles suivantes par courriel à David Carrière et Michèle COLIN (secrétariat) un avis d’entrée vous sera alors délivré :

Nom :
Prénom :

Date et lieu de naissance :
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Nom de l'employeur :

Ces informations doivent être envoyées au mieux deux jours avant la date du séminaire.

Lors de votre venue vous devez vous présenter avec une carte d'identité ou un passeport en cours de validité. L'entrée sur le site se fait par l'entrée principale ou porte Nord (suivre le lien ci-dessous), un badge vous y sera remis. Demandez à l'accueil le Bât.125 ils vous renseigneront. Les séminaires se déroulent en pièce 157 (1er étage). En cas de problème vous pouvez contacter le secrétariat au 01.69.08.64.81.



 Formalities for entering the CEA Saclay site for LIONS seminars

 

To enter in CEA Saclay you need to send the following personal data to David Carrière and Michèle COLIN (secretariat):


Last Name :
First Name :

Place and date of birth :
Nationality :

Employer Name :


These informations must be preferably sent at least two days before the seminar date.

When you come you must have a valid ID card or passport with you.

The entrance in CEA Saclay is through the main entrance or north entrance (see link below), a pass will be delivered. Ask at the “accueil” the path for the building 125. LIONS seminars take place in room 157 (first floor).

Any questions/troubles do not hesitate to contact our secretariat: 01.69.08.64.81.

 

Informations:  Access
Contact:  David Carrière

#26 - Last update : 10/10/2012

 

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