Lyotropic Smectic B Phase Formed in Suspensions of Charged Colloidal Platelets
Dzina Kleshchanok,*,† Peter Holmqvist,‡ Janne-Mieke Meijer,† and Henk N. W. Lekkerkerker†
†Van’t Hoff Laboratory, Debye Institute for Nanomaterials Science, Utrecht University, The Netherlands
‡Soft Condensed Matter Group, Institute of Complex Systems (ICS-3), Forschungszentrum Juelich, Germany
We present the first observation of a smectic B (SmB) phase in a system of charged colloidal gibbsite platelets suspended in dimethyl sulfoxide (DMSO). The use of DMSO, a polar aprotic solvent, leads to a long range of the electrostatic Coulomb repulsion between platelets. We believe this to be responsible for the formation of the layered liquid crystalline phase consisting of hexagonally ordered particles, that is, the SmB phase. We present high resolution X-ray scattering experiments for different concentrations in the SmB phase additionally supporting the phase characterization. The identification of the formation of a SmB phase that is not only governed by the shape and concentration of the colloidal particles but also by their anisotropic interactions is of fundamental interest. In addition, our finding challenges theory and simulation to predict this phase.
1. Dzina Kleshchanok, Peter Holmqvist, Janne-Mieke Meijer, and Henk N. W. Lekkerkerker, Lyotropic Smectic B Phase Formed in Suspensions of Charged Colloidal Platelets, J. Am. Chem. Soc. 2012, 134, 5985−5990