Promoteur de thèse: Monsieur Pascal Damman
Co-promoteur: Monsieur E. Raphael
Résumé de la dissertation: Chains dynamics, specially when repulsive interactions come at play, remains an unsolved problem of polymer physics, although understanding this dynamics could improve our knowledge about crucial phenomena at the cellular level. For instance, the transport of RNA across the nuclear pore or the injection of viral DNA plasmid by bacteriophages into a bacteria. Alas, studying repulsive polymers in confined geometries is as experimentally difficult as it is biologically relevant. In spite of recent advances in « nanorheology », from the Brownian motion of local probes, or in computer simulation, designing experiments matching the biological parameters is near impossible. All this leads to unchallenged theoretical tools. Even the straightforward problem of polymer translocation remains lively debated.
As a way out of this impasse, we propose to use granular chain as a macroscopic equivalent of a polymer.
First we were interested in the internal structure of a stack of granular chains at rest and we rationalized it with polymer analogy. Then we added energy in our experimental system via mechanical excitations which appears to be analogous to the equilibration with a thermal bath. Finally we studied the dynamics of chains in specific confined geometries and compared it to both molecular dynamics simulation and theoretical tools.