# Mesoscale Organization and Dynamics in Binary Ionic Liquid Mixtures

## TL;DR

This study explores how mesoscale structures influence ion transport and dielectric properties in binary ionic liquids, revealing that mixing can significantly enhance dielectric permittivity through tunable mesoscale morphologies.

## Contribution

It demonstrates that mesoscale morphologies in ionic liquids can be controlled via mixing to optimize dielectric and transport properties, a novel approach for designing ionic liquids.

## Key findings

- Mesoscale morphologies can be tuned by mixing to enhance dielectric permittivity.
- Distinct liquids with properties deviating from neat components are formed.
- Interfacial dynamics and aggregate morphologies influence ion transport.

## Abstract

The impact of mesoscale organization on dynamics and ion transport in binary ionic liquid mixtures is investigated by broadband dielectric spectroscopy, dynamic-mechanical spectroscopy, x-ray scattering, and molecular dynamics simulations. The mixtures are found to form distinct liquids with macroscopic properties that significantly deviate from weighted contributions of the neat components. For instance, it is shown that the mesoscale morphologies in ionic liquids can be tuned by mixing to enhance the static dielectric permittivity of the resulting liquid by as high as 100$\%$ relative to the neat ionic liquid components. This enhancement is attributed to the intricate role of interfacial dynamics associated with the changes in the mesoscopic aggregate morphologies in these systems. These results demonstrate the potential to design the physicochemical properties of ionic liquids through control of solvophobic aggregation