Ionic liquid-in-water emulsions stabilized by molecular and polymeric surfactants

Abstract

Ionic liquids have drawn notable attention for their unique solvent properties and use in applications like batteries and chemical separations. While many ionic liquids are water soluble, there are numerous examples of ionic liquids that are sufficiently hydrophobic to remain phase separated from water. However, relatively little is known about the stability and properties of ionic liquid-in-water emulsions. Here, we survey a series of ionic liquid-in-water emulsions stabilized by a range of ionic and nonionic molecular surfactants and polymers. To assess droplet stability and dynamics, we characterize the ionic liquid-surfactant interfacial tension, describe qualitative coarsening rates, and quantify droplet solubilization rate. In some instances, we observe unexpected spontaneous formation of complex double and triple emulsions. Our observations highlight approaches for ionic liquid emulsion formulation and provide insight into how to address challenges surrounding stabilization of ionic liquid-in-water droplets with molecular surfactants.

Virtual Special Issue Honoring the Legacy of Dr. Bettye Washington Greene

“…This section also includes Gahan et al's 26 studies toward understanding the role of membrane composition in bacterial quorum sensing as well as work characterizing the various biologically relevant membranes from Wood et al, 35 Faizi et al, 36 and Bali et al 37 ■ IONIC LIQUIDS, LIQUID CRYSTALS, AND EMULSIONS This section of the VSI includes articles that describe a variety of different liquid colloidal solutions. Edgehouse et al 38 and Han et al 39 both describe the characterization of various ionic liquids, Darlington et al 27 report on the use of biocompatible ionic liquids to improve blood detection, and Birrer et al 28 describe ionic liquid-in-water emulsions. Wang et al 29 and Norouzi et al 40 report on liquid crystals, while Pinẽres-Quinõnes et al 41 characterize emulsions of thermotropic liquid crystals.…”