Amphiphile Self-assembly in Deep Eutectic Systems

Understanding and manipulating micelle morphology is key to exploiting surfactants in applications from templating mesoporous materials to formulation of creams and lipid particles for drug delivery. The drive to replace toxic organic solvents in extractions, syntheses and materials processing as well as the shift towards use of natural components in formulations has led to increasing demand for sustainable solvents that can support molecular self-organisation in a range of scenarios. Recent studies have demonstrated that surfactant self-assembly occurs in a variety of Deep Eutectic Systems (DES), solvents which are rapidly developing as safer, low cost alternatives to ionic liquids and organic solvents. In these systems both the nature of the surfactants and interactions of the surfactant molecule with the solvent components influence the size, shape and morphology of the self-assembled structures formed. The majority of studies concentrate on Type III DES comprising organic salts and hydrogen bond donors, but recently some studies have been reported on DES composed of a metal salt with organic hydrogen bond donors, Type IV DES. In this work we review the micellization of ionic, non-ionic and zwitterionic surfactants and lipids in various DES with a view to understand the role played by DES constituents and structure in self-assembly of amphiphilic molecules. • Reviews self-organisation of surfactants and lipids in novel ”green” deep eutectic solvents • Micellisation and self-assembly in DES is important in fields from ”naturals” formulation to templating • DES composition is key to understanding structure formation in these systems.