Seminars

PMMH’s weekly seminar is held every Friday at 11 am (map)

Contact :
Benoit Semin
Sylvain Patinet
Etienne Reyssat
responsables-seminaires (arobase) pmmh.espci.fr

PMMH
BARRE CASSAN
BAT A 1ER ETAGE CASE 18
7 QUAI SAINT BERNARD
75005 PARIS
France

Tel : (33) 1 40 79 45 22


Séminaire PMMH Jasna Brujic

Vendredi 4 février 11:00-12:00 - Salle réunion PMMH 1

Jasna Brujic, NYU

Dynamics of Active Droplets

Most active particles, such as Janus colloids, are anisotropic and their orientation determines the swimming direction. This direction is randomized by thermal fluctuations and their motility is described by passive rotational diffusion. By contrast, oil droplets of DEP spontaneously break symmetry as they dissolve in water, resulting in self-propulsion at a fixed speed, largely independent of surfactant concentration. Droplet trajectories also undergo slow angular diffusion, but they change direction via active interactions with micelles in solution. Increasing their bulk concentration decreases the effective diffusion constant four orders of magnitude. The turning of the droplets may be governed by fluctuations in surrounding micellar concentrations, which in turn polarize the surfactant gradient on the surface that directs droplet motion. This active system allows one to tune the effective temperature of the system without changing the velocity. Such control could be useful for studying active phenomena, such as non-equilibrium phase separation and clustering.

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Seminars  (3)

Information for the speakers

The audience is composed of people with rather heterogeneous backgrounds including specialists in solids, fluids, granular flows, statistical physics... so the idea is to keep your talk understandable by people not necessarily working in your field... The seminar time slot runs from 11am to noon so the best is to make the talk last around 45 minutes to leave some time for discussion.

Link to cofee seminar (internal, every Thursday)

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Practical information

Laboratoire : 01 40 79 45 22
Directeur : Damien Vandembroucq
Codirecteur : Philippe Petitjeans
Administratrice : Frédérique Auger (01 40 79 45 22)
Gestionnaire : Claudette Barez (01 40 79 58 53)
Courriel : dir (arobase) pmmh.espci.fr