Two-Dimensional Colloidal Dispersions at Aqueous-Liquid Crystal Interfaces
Gary M. Koenig Jr.1, I-Hsin Lin2, and Nicholas L. Abbott1. (1) Department of Chemical and Biological Engineering, University of Wisconsin-Madison, 1415 Engineering Dr., Madison, WI 53706-1691, (2) Chemical and Biological Engineering, University of Wisconsin-Madison, 1415 Engineering Drive, Madison, WI 53706
Particles confined to liquid-liquid interfaces have been widely used to stabilize Pickering emulsions. A variety of interactions, including capillary and electrostatic interactions, have been identified to influence the organizations of particles at these interfaces. This presentation will report an investigation of particle organization at liquid-liquid interfaces where one of the liquids was a liquid crystal. Whereas interparticle forces mediated by liquid crystals in bulk dispersions are known to be strong (1000 kT), little is understood about the influence of liquid crystal mediated forces for particles confined to interfaces. Exploratory experiments have revealed that liquid crystalline order within one of the condensed phases lead to a number of particle-based phenomena that were not observed at interfaces of isotropic liquids. For example, microparticles at the liquid crystal-water interface have been found to assemble into chain-like structures not seen at isotropic liquid interfaces. Furthermore, ordering transitions within the liquid crystals that were driven by the presence of surfactant-coated microparticles were observed.