Bulk and interfacial nanostructure and properties in deep eutectic solvents: Current perspectives and future...

Area of Science:

• Materials Science
• Physical Chemistry
• Chemical Engineering

Background:

• Deep eutectic solvents (DESs) are tunable solvents with growing interest due to their unique properties and diverse applications.
• DESs are formed from hydrogen bond donors and acceptors, exhibiting lower melting points than individual components.
• Their distinct bulk liquid and interfacial nanostructures arise from complex molecular interactions.

Purpose of the Study:

• To provide an overview of the current understanding of DES nanostructure in bulk liquids and at interfaces.
• To clarify the definition of DESs, distinguishing them from ionic liquids (ILs).
• To highlight structure-property relationships and identify research gaps and future directions.

Main Methods:

• Literature review and appraisal of existing research on DES nanostructure.
• Analysis of intra- and inter-molecular interactions governing DES properties.
• Comparison of DESs with conventional solvents and ionic liquids.

Main Results:

• DES nanostructure significantly influences physicochemical properties, impacting potential applications.
• A gap exists in understanding the factors governing DES solvent properties.
• Recent work suggests trends in structure-property relationships, alongside inconsistencies in the literature.

Conclusions:

• Further research is needed to fully elucidate DES nanostructure and its impact on properties.
• A robust framework for systematic investigation of DESs is essential for future development.
• Clarifying DES definitions and structure-property relationships will accelerate technological advancements.