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Seminars
Contact :
Hèléne Berthoumieux
Tel : +33 (0) 1 40 79 xx xx
Paddy Royall
Tel : +33 (0) 1 40 79 xx xx
Gulliver seminars take place on Mondays at 11:30 AM in the F304 room, and typically last one hour including questions. The seminars are in English, and the scientific topics are mainly those studied in the laboratory.
Gulliver Seminar : Emilie Verneuil (ESPCI)
Clean oxidized silicon wafers are high energy surfaces : most liquids
spontaneously spread on them. Ahead the contact line of sessile droplets, a nanometer-thin film called "precursor film" spreads around the droplet. The spreading dynamics and morphology of these precursor films have long been thought as a way to quantify interactions of liquids at solid interfaces. Most past studies dealt with systems for which long range interactions were repulsive and total wetting conditions were met.
However, liquid/surface and liquid/liquid interactions were found intricate and could hardly be separated in these systems. The liquids that we consider in the present study are polymer melts (polybutadiene, polyisoprene, polystyrene) exhibiting pseudo-partial wetting condition on oxidized silicon wafers : a sessile droplet at rest coexists with a film. By taking advantage of ellipsometric microscopy, we study the morphology and dynamics of such films, and quantitatively probe the interactions at stake between the monomers and the surface. Remarkably, the outermost part of the film consists of a quasi-2D gas of semi-dilute flat chains. In addition to providing robust measurements of molecular interactions at solid interfaces, our work highlights the need to re-think the theoretical
existing framework for dense precursor films.
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Seminars (2)
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Gulliver Seminar : Haim Diamant (Tel Aviv University)
Lundi 29 avril de 11h30 à 12h30 - C162
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Gulliver seminar : Matthew Turner
Lundi 13 mai de 11h30 à 12h30 - C162
The audience is often heterogeneous - because of the wide range of scientific topics covered in the lab - so planning a talk for a broader audience would be preferred. The seminar is in English, and speakers are thus invited to prepare their slides in English.
The seminar starts at 11:30 AM. The speaker is asked to arrive in the lab at least 15 minutes in advance to set up their computer. The talks last typically 45 minutes, and are followed by a discussion time.