Microphase separation in oil-water mixtures containing hydrophilic and hydrophobic ions

Abstract

We develop a lattice-based Monte Carlo simulation method for charged mixtures capable of treating dielectric heterogeneities. Using this method, we study oil-water mixtures containing an antagonistic salt, with hydrophilic cations and hydrophobic anions. Our simulations reveal several phases with a spatially modulated solvent composition, in which the ions partition between water-rich and water-poor regions according to their affinity. In addition to the recently observed lamellar phase, we find tubular, droplet, and even gyroid phases reminiscent of those found in block copolymers and surfactant systems. Interestingly, these structures stem from ion-mediated interactions, which allows for tuning of the phase behavior via the concentrations, the ionic properties, and the temperature.

arXiv comment5 pages, 4 figures

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Cited by in corpus (6)

• Nonequilibrium phase transitions of sheared colloidal microphases: Results from dynamical density functional theory
• Mesoscale phase separation of skyrmion-vortex matter in chiral magnet-superconductor heterostructures
• Theory of electrolytes including steric, attractive, and hydration interactions
• How antagonistic salts cause nematic ordering and behave like diblock copolymers
• Ionically charged topological defects in nematic fluids
• The vanishing water/oil interface in the presence of antagonistic salt