Accueil du site > Colloïdes, Verres et Nanomatériaux > Equipe : Matière Molle > Thème : Structure, confinement et jamming de colloïdes
Thème : Structure, confinement et jamming de colloïdes
Présentation
Notre équipe s’intéresse aux systèmes colloïdaux denses, à des fractions volumiques proches des transitions d’encombrement et des transitions vitreuses ou des cristaux colloïdaux dont le comportement est dominé par des joints de grains. Nous concevons des systèmes colloïdaux modèles et développons des techniques expérimentales pour leur observation : diffusion de lumière en champ proche, des pinces optiques, la microscopie confocale…
Nous avons par exemple mise au point une expérience de diffusion de lumière résolue en temps et dans l’espace pour mesurer directement les hétérogénéités spatiales de la dynamique dans les systèmes très encombrés.
On étudie par ailleurs des colloïdes piégés à l’interface de fluides simples ou de fluides complexes. Des dispositifs optiques permettent de mesurer leur diffusion, l’angle de contact et leurs interactions.
Current researches
Membres
| PERMANENTS | NON PERMANENTS |
Glass/jamming transition and driven colloids
Glass/jamming transition and driven colloids We investigate the spontaneous dynamics of colloids near a glass/jamming transition using novel space and time-resolved dynamic light scattering techniques recently developed at L2C. In particular, we study colloidal hard spheres (HS) as a model system to investigate the glass transition. Recently, we have significantly extended previous measurements of the equilibrium dynamics of HS, demonstrating the cross-over from a “mode coupling theory-like” regime to (...)
Surfoids : Colloids @ Fluid Interfaces
Surfoids : Colloids @ Fluid Interfaces The interface between two fluids is extremely efficient to trap particles ranging from nanometer to millimeter sizes. In the past this strong 2D confinement has been used to address fundamental problems of condensed matter physics considering colloids as “big” atoms. Nowadays the interest for these systems is enriched by their large impact for applications and industrial processing. In particular making functional materials by colloidal self-assembly at the (...)
Colloidal metallurgy
Confined colloids are used also to investigate or create new materials. Confinement of nanoparticles in the grain-boundaries of polycrystalline soft materials allows their visualization by light or confocal microscopy. This is illustrated in the two pictures obtained with different crystallization rates. Our current project on colloidal metallurgy takes advantage of the much larger characteristic length and time scales, much softer elasticity, and the optical transparency of a colloidal polycrystal (...)
Colloidal liquid crystals & Confinement by liquid crystals
Anisotropic particles due their extra orienatational degree of freedom have in general a much richer behavior than spherical ones. They can form liquid crystalline phases at high concentrations. At lower concentrations, their orientation can be controlled by an external field : electric or elastic as in the case of suspensions in a liquid crystal. In a composite, their proper anisotropic properties can be transferred to the matrix, at the macroscopic scale. Colloidal liquid crystal Anisotropic (...)
