Séminaires café 2020

27 Février Mayarani M (Post-doctorante au PMMH)
Interface assisted evaporative self-assembly of soft colloids
Monolayers of colloids adsorbed at fluid interfaces and their transfer onto solid surfaces are crucial to fundamental science as well as for soft nanotechnology. While the deposition of homogeneous colloidal monolayers by evaporative drying of a colloidal drop is severely hindered by the well known ‘coffee-ring’ effect, I will discuss a simple strategy that exploits the interface assisted self-assembly combined with controlled evaporation to create uniform monolayers of soft microgel particles. The surface activity of the microgel particles, the interparticle interactions, and the kinetics of evaporation are tuned to generate an array of novel two-dimensional structures, including monolayer coffee-rings, loosely packed uniform layers, and interconnected cell-like patterns with extraordinary richness and diversity. In my talk, I will also discuss the occurrence of an order-disorder transition in the self-assembled monolayers of soft colloids. The evolution of the viscoelasticity of the soft microgel particle-laden fluid-air interface, quantified by using a multiple-particle tracking passive microrheology technique and the suppression of the “coffee-ring effect” for hard colloids in the presence of microgel particles will also be discussed. Finally, the origin of the depletion zones observed in evaporative self-assembly will be presented in detail.
24 juin Marc Fermigier (Enseignant-chercheur de l’ESPCI)
Présentation du projet « Du Carbone à l’Or Olympique » en vue de Paris 2024
8 juillet Hector Ignacio Ramos Urra (Doctorant au PMMH)
Bacteria swimming in complex fluids
15 juillet Roméo Antier (Doctorant au PMMH)
Softening effect in periodically forced creased plates
10 septembre Pas de séminaire café : soutenance de thèse de Reda Belbahri
17 septembre Benoît Semin (Chargé de recherche au PMMH)
Coronavirus, ventilation and CO2
Décalé au vendredi 11 septembre
08 octobre Frédérique Auger (Administratrice au PMMH)
L’administratif du chercheur
05 novembre Valentin Laplaud (Post-doctorant au PMMH)
Mechanical properties of the cell actin cortex : looking for evidence of poroelasticity
12 novembre Tao Liu (Doctorant au PMMH)
Decay of streamwise streaks and rolls in plane Couette-Poiseuille flow
19 novembre Lucas Prévost (Doctorant au PMMH)
Flexible micro-helices : fabrication and deformation in viscous flows
26 novembre Aditya Jha (Doctorant au PMMH)
Complex Fluids Rebounds
03 décembre Samantha Kucher (Doctorant au PMMH)
Propagating localized structure in a 1D Faraday experiment
10 décembre Ananyo Maitra (Post-doctorant au LJP)
Time cholesteric : A new, active, liquid crystal
Active matter theories generally augment descriptions of passive liquid crystals with nonequilibrium forces and currents, thereby addressing how activity affects these structures. In this talk, I will ask a less common question : can activity create new liquid crystals — spatiotemporal structures impossible in passive systems ? I will demonstrate that the interplay of chiral asymmetry, which is important in multiple experimental situations, and activity yields new liquid crystalline phases and will describe a state of this type — a time-cholesteric phase — in detail, which has recently been observed in experiments. This spontaneously rotating uniaxial phase — the first truly nonequilibrium phase in active systems — will be shown to be unusually stable even in momentum-conserved, incompressible fluids, unlike non-rotating uniaxial phases which are generically unstable. Together, my talk will demonstrate that activity allows for novel families of liquid-crystals, with unusual properties, which are both experimentally realisable and can be engineered artificially.
17 décembre Antonin Eddi (Chargé de recherche au PMMH)
Les vacations à l’Université : une tentative d’approche quantitative
24 décembre Pas de séminaire café
31 décembre Pas de séminaire café

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Informations Pratiques

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