Highly stable ionic liquid-in-water emulsions as a new class of fluorescent sensors for metal ions: the case study of Fe3+ sensing

Sergio Murgia,Francesco Isaia,Davide Demurtas,Luca Conti,Marianna Mamusa,Vito Lippolis,Alexandre Bettoschi,Claudia Caltagirone,Debora Berti,Andrea Bencini,Claudia Giorgi

doi:10.1039/c5ra05055c

Abstract

A stable fluorescent ionic liquid can act as a fluorescent sensor for metal ion recognition.

Highlights

Ionic liquids (ILs) are a class of electrolytic solvents endowed with appealing characteristics, including non- ammability, negligible vapor pressure, and high chemical and thermal stability
Given the size and the shape of the aggregates observed, two types of very different colloidal dispersions can be envisaged to explain their nature: spherical hollow vesicles, whose shell is constituted by a double layer of self-assembled IL surrounding an aqueous core or, alternatively, emulsion droplets originated by the segregation of the IL itself
The core's diameter was set to 200 nm with 0.2 polydispersity index, while the shell thickness was set to 2 nm according to the IL's molecular dimensions

Summary

Introduction

Ionic liquids (ILs) are a class of electrolytic solvents endowed with appealing characteristics, including non- ammability, negligible vapor pressure, and high chemical and thermal stability. Practical applications would plainly bene t from the formulation of stable binary IL-in-water emulsions, not to mention the central importance the study of the pristine IL-water interface may have from a theoretical point of view. A very limited number of examples of oil-in-water,[14,15] truly binary, stable, and surfactant-free emulsions has been They have been widely investigated in recent years since they can nd application in various elds.[1,2,3] Remarkably, they have been used as water or oil substitutes, as well as additives or surfactants in the formulation of a huge number of so matter based colloidal systems, such as micelles, microemulsions, liquid crystals, and emulsions.[4,5,6,7] to traditional oil-in-water emulsions,[8,9] ILin-water emulsions are thermodynamically unstable dispersions, whose kinetic stability is generally increased by adding to the binary system a number of different stabilizers, including surfactants,[10] liquid crystals, ne particles (Pickering emulsions),[11] carbon nanotubes,[12] or microgels.[13]

Methods

Results

Conclusion