title: Capillary-induced giant elastic dipoles in thin nematic films.
abstract: Directed and true self-assembly mechanisms in nematic liquid crystal colloids rely on specific interactions between microparticles and the topological defects of the matrix. Most ordered structures formed in thin nematic cells are thus based on elastic multipoles consisting of a particle and nearby defects. Here, we report, for the first time to our knowledge, the existence of giant elastic dipoles arising from particles dispersed in free nematic liquid crystal films. We discuss the role of capillarity and film thickness on the dimensions of the dipoles and explain their main features with a simple 2D model. Coupling of capillarity with nematic elasticity could offer ways to tune finely the spatial organization of complex colloidal systems.
authors.affiliation: Université de Tunis El Manar, Faculté des Sciences de Tunis, LR99ES16 Laboratoire Physique de la Matière Molle et de la Modélisation Électromagnétique, 2092, Tunis, Tunisia;
authors.forename: Haifa
authors.initials: H
authors.lastname: Jeridi
authors.affiliation: Department of Physics, McGill University, Montreal, QC H3A 2T8, Canada;
authors.forename: Mohamed A
authors.initials: MA
authors.lastname: Gharbi
authors.affiliation: Université de Tunis El Manar, Faculté des Sciences de Tunis, LR99ES16 Laboratoire Physique de la Matière Molle et de la Modélisation Électromagnétique, 2092, Tunis, Tunisia;
authors.forename: Tahar
authors.initials: T
authors.lastname: Othman
authors.affiliation: Laboratoire Charles Coulomb, UMR 5521 CNRS-Université de Montpellier, Montpellier 34095, F-France christophe.blanc02@univ-montp2.fr.
authors.forename: Christophe
authors.initials: C
authors.lastname: Blanc
keywords: colloids; dispersions; liquid crystals; self-assembly; thin films