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Updated: Sep 22, 2025
Phase Behavior of Charged Vesicles Under Symmetric and Asymmetric Solution Conditions Monitored with Fluorescence Microscopy
Published on: October 24, 2017
Long-ranged heterogeneous structure in aqueous solutions of the deep eutectic solvent choline and geranate at the
Alfredo Felipe1, Christopher A Lovenduski2, Joseph L Baker2
1Department of Chemistry, Department of Applied Physics and Materials Science, and ¡MIRA! the Center for Materials Interfaces in Research and Applications, Northern Arizona University, Flagstaff, Arizona, USA. gerrick.lindberg@nau.edu.
Abstract:
The deep eutectic solvent choline and geranate (CAGE) has shown promise in many therapeutic applications. CAGE facilitates drug delivery through unique modes of action making it an exciting therapeutic option. We examine the behavior of aqueous CAGE solutions at a liquid-vapor interface. We find that the liquid-vapor interface induces large oscillations in the density, which corresponds to spontaneous segregation into regions enriched with geranate and geranic acid and other regions enriched with water and choline. These heterogeneities are observed to extend nanometers into the liquid. Additionally, we find that the geranate and geranic acid orient so that their polar carboxyl or carboxylate groups are on average pointed toward the layer containing water and choline. Finally, we report surface tension and thermal expansion coefficients for various concentrations of aqueous CAGE. We find a non-monotonic trend in the surface tension with concentration. The structural and thermodynamic properties we report provide a new perspective on CAGE behavior, which helps deduce the action of CAGE in more sophisticated systems and inspire other studies and applications of CAGE and related materials.
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