title: On phase behavior and dynamical signatures of charged colloidal platelets.
abstract: Charged platelet suspensions, such as swelling clays, disc-like mineral crystallites or exfoliated nanosheets are ubiquitous in nature. Their phase behaviours are nevertheless still poorly understood: while some clay suspensions form arrested states at low densities, others exhibit an equilibrium isotropic-nematic transition at moderate densities. These observations raise fundamental questions about the influence of electrostatic interactions on the isotropic-nematic transition and the organisation of charged platelets. We investigate the competition between anisotropic excluded-volume and repulsive electrostatic interactions in suspensions of charged colloidal discs, by means of Monte-Carlo simulations and characterization of the dynamics of the structures. We show that the original intrinsic anisotropy of the electrostatic potential between charged platelets not only rationalizes generic features of the complex phase diagram of charged colloidal platelets such as Gibbsite and Beidellite clays, but also predicts the existence of novel structures. Furthermore, we find evidences of a strong slowing down of the dynamics upon increasing density.
authors.affiliation: LPTMS, CNRS and Université Paris-Sud, UMR8626, Bat. 100, 91405 Orsay, France.
authors.forename: Sara
authors.initials: S
authors.lastname: Jabbari-Farouji
authors.affiliation: Université Paris-Sud, Laboratoire de Physique Théorique, CNRS UMR 8627, Bâtiment 210, 91405 Orsay Cedex, France.
authors.forename: Jean-Jacques
authors.initials: JJ
authors.lastname: Weis
authors.affiliation: Université Paris-Sud, Laboratoire de Physique des Solides, CNRS UMR 8502, Bâtiment 510, 91405 Orsay Cedex, France.
authors.forename: Patrick
authors.initials: P
authors.lastname: Davidson
authors.affiliation: Laboratoire PECSA, CNRS UMR 7195, Université Pierre et Marie Curie Case Courrier 51, 4 place Jussieu 72522 Paris Cedex 5, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Levitz
authors.affiliation: LPTMS, CNRS and Université Paris-Sud, UMR8626, Bat. 100, 91405 Orsay, France.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Trizac