Switching the structural force in ionic liquid-solvent mixtures by varying composition

Abstract

The structure and interactions in electrolytes at high concentration have implications from energy storage to biomolecular interactions. However many experimental observations are yet to be explained in these mixtures, which are far beyond the regime of validity of mean field models. Here, we study the structural forces in a mixture of ionic liquid and solvent that is miscible in all proportions at room temperature. Using the surface force balance to measure the force between macroscopic smooth surfaces across the liquid mixtures, we uncover an abrupt increase in the wavelength above a threshold ion concentration. Below the threshold concentration the wavelength is determined by the size of the solvent molecule, whereas above the threshold it is the diameter of a cation-anion pair that determines the wavelength.

PRL in press

References in corpus (3)

• The Electrostatic Screening Length in Concentrated Electrolytes Increases with Concentration
• Experimental observation of structural crossover in binary mixtures of colloidal hard spheres
• Direct Observation in 3d of Structural Crossover in Binary Hard Sphere Mixtures

Cited by in corpus (9)

• Primitive Model Electrolytes in the Near and Far Field: Decay Lengths from DFT and Simulations
• From solvent free to dilute electrolytes: Essential components for a continuum theory
• Screening Lengths in Ionic Fluids
• Structural interactions in ionic liquids linked to higher order Poisson-Boltzmann equations
• Anomalous Underscreening in the Restricted Primitive Model
• Gelation, Clustering and Crowding in the Electrical Double Layer of Ionic Liquids
• Spin-Glass Charge Ordering in Ionic Liquids
• Bayesian unsupervised learning reveals hidden structure in concentrated electrolytes
• Forces between Silica Particles in Isopropanol Solutions of 1:1 Electrolytes