Interplay of anisotropy in shape and interactions in charged platelet suspensions

Sara Jabbari-Farouji 1, 2 Jean-Jacques Weis 3 Patrick Davidson 4 Pierre Levitz 5 Emmanuel Trizac 2

Journal of Chemical Physics, American Institute of Physics (AIP), 2014, 141, pp.224510

Motivated by the intriguing phase behavior of charged colloidal platelets, we investigate the structure and dynamics of charged repulsive disks by means of Monte-Carlo simulations. The electrostatic interactions are taken into account through an effective two-body potential, obtained within the non-linear Poisson-Boltzmann formalism, which has the form of anisotropic screened Coulomb potential. Recently, we showed that the original intrinsic anisotropy of the electrostatic potential in competition with excluded volume effects leads to a rich phase behavior that not only includes various liquid-crsytalline phases but also predicts the existence of novel structures composed of alternating nematic-antinematic sheets. Here, we examine the structural and dynamical signatures of each of the observed structures for both translational and rotational degrees of freedom. Finally, we discuss the influence of effective charge value and our results in relation to experimental findings on charged platelet suspensions.

  • 1. LIPhy, Laboratoire Interdisciplinaire de Physique
  • 2. LPTMS - Laboratoire de Physique Théorique et Modèles Statistiques
  • 3. Laboratoire de Physique Théorique
  • 4. LPS - Laboratoire de Physique des Solides
  • 5. PECSA - Physicochimie des Electrolytes, Colloïdes et Sciences Analytiques