2018/06/26 by Pagès, Josep M., Straube, Arthur V., Tierno, Pietro +2
#FOS: Physical sciences #Soft Condensed Matter (cond-mat.soft)
paper · doi:10.48550/arxiv.1806.09913
We combine experiments, theory, and simulations to investigate the coexistence of nonequilibrium phases emerging from interacting colloidal particles that are electrokinetically propelled in a nematic liquid crystal solvent. We directly determine the mechanical pressure within the radial assemblies and measure a non-equilibrium equation of state for this athermal driven system. A generic model combines phoretic propulsion with the interplay between electrostatic effects and liquid-crystal-mediated hydrodynamics, which are effectively cast into a long-range interparticle repulsion, while elasticity plays a subdominant role. Simulations based on this model explain the observed collective organization process and phase coexistence quantitatively. Our colloidal assemblies provide an experimental test-bed to investigate the fundamental role of phoretic pressure in the organization of driven out-of-equilibrium matter.