ESPCI web site
Séminaire Café (Interne)
Il s’agit d’un exposé assez court (20 min) et assez informel.
Prière aux conférencier·ère·s de ne jamais dépasser 30 min et de vérifier la compatibilité avec le projecteur avant le séminaire.
Les séminaires ont lieu les jeudis après la réunion du laboratoire qui débute à 13h30 dans la bibliothèque du labo sur le campus Jussieu, Barre Cassan, Bât A, 1er étage.
Pour suggérer un titre et envoyer un abstract, contacter 
et 
.
Coffee seminars are supposed to be short and informal presentations (20 min).
Please never last longer than 30 min and check the compatibility of the projector with your computer before the seminar.
Location : Campus Jussieu, Barre Cassan, Bât A, 1er étage
7 quai Saint Bernard
75005 Paris
To suggest a title or send an abstract, please contact and .
| 2 octobre | Sandeep Saha - IIT Kharagpur The intriguing annual migration of the dragonfly Pantala flavescens |
| 9 octobre | Victor Ziapkoff - PhD student at LPS Stabilizing thin films from rupture using salt The production of foam in a salty environment, presents challenges as the ionic strength changes the surfactant interactions, which in turn can result in changes in foam stability. The most drastic destabilization mechanism is coalescence, which occurs as the thin film between bubbles ruptures. We study the impact of salt on film coalescence. A classical experiment consists of pulling a film from a liquid bath. This experiment has been used to follow film thinning through drainage and evaporation. Recently, a study with a non-ionic surfactant showed that film drainage slows down in the presence of salt because it increases its viscosity. We study the stability of films from solutions of a cationic surfactant, tetradecyltrimethylammonium bromide (TTAB) with and without NaCl. We measure film rupture and film thickness under controlled humidity condition. We have carried out statistics on film rupture and shown that even for films made with solutions containing salt, higher humidity leads to greater stability. We now show that a film pulled out of a salty bath is more stable regardless of ambient humidity. We have measured the film thickness over time at the top of the film. The two-mechanisms responsible for film thinning – evaporation and drainage – are not affected by the presence of salt whatever the atmospheric humidity. Relative humidity only affects evaporation at film thicknesses below 250 nm. Surprisingly, we observed that the primary effect of salt is to stabilize very thin (5 nm) films. This in-depth study of foam films with salt can provide tools to understand how to stabilize seawater foam, where they can be used for depollution. |
| 16 octobre | Présentations des 2ème année - PMMH Hugo Krebs & Eloïse Halouchery |
| 23 octobre | Mario Marcel - École Estienne Illustrations scientifiques |
| 30 octobre | Présentations des 2ème année - PMMH Paul Bienvenu & Hugo Delrieu |
