Marina TORRES LAZARO I Liquid crystal self-organization of colloids in complex environments.
Soutenance de thèse
- Hong XU, Université de Lorraine (rapporteur)
- Enrique VELASCO, Universidad Autónoma de Madrid (rapporteur)
- Patrick DAVIDSON, LPS (examinateur)
- Anja KUHNHOLD, University of Freiburg (examinateur)
- Rik WENSINK, LPS (directeur de thèse)
The work presented in this thesis focuses on a theoretical study of liquid crystal (LC) self-organization of colloidal rods or platelets in complex environments. Explorations are made using statistical theory based on Onsager and mean-field theory combined with large-scale computer simulations. The first case we consider are colloidal discs immersed in reversibly polymerizing rods where both components are capable of developing nematic order. We map out the phase diagrams that feature a number of multi-phase coexistences and discuss the phenomenon of reversible polymerization in anti-nematic environments. The second example concerns colloid rods and platelets immersed in a chiral thermotropic liquid crystal. These so-called hybrid molecular-colloidal liquid crystals are demonstrated to exhibit enhanced biaxial order, surface-anchoring mediated liquid-liquid phase separation, and exotic bi-helical hybrid colloidal-molecular organizations at significant colloid content. The last topic addresses the mesoscopic self-assembly of chiral colloidal rods mixed with non-adsorbing polymers. Depending on the conditions, these mixtures are known to form tactoids, membrane-shaped liquid rafts, as well as twisted ribbons. Using semi-grand canonical Monte Carlo computer simulation, we address the morphology and internal structure of these LC droplets and compare our findings with recent experimental results on filamentous fd virus rods.
