157
© The Editor(s) (if applicable) and The Author(s), under exclusive license to
Springer Nature Switzerland AG 2021
S. Fourmentin et al. (eds.), Deep Eutectic Solvents for Medicine, Gas
Solubilization and Extraction of Natural Substances, Environmental Chemistry
for a Sustainable World 56, https://doi.org/10.1007/978-3-030-53069-3_5
Chapter 5
Hydrophobic Deep Eutectic Solvents
Emily L. Byrne, Mark Gilmore, Leila Moura, Małgorzata Swadźba-Kwaśny,
and John D. Holbrey
Contents
5.1 Introduction
158
5.2 Design of Hydrophobic Deep Eutectic Solvents
158
5.2.1 From Hydrophobic Ionic Liquids to Hydrophobic Deep Eutectic Solvents
158
5.2.2 Hydrophobicity Through Organic Salts with Hydrophobic Hydrogen Bond
Donors
159
5.2.3 Losing the Salt, Abandoning the Hydrogen Bond Acceptor-Hydrogen Bond
Donor Strategy
161
5.3 Applications
163
5.3.1 Extraction of Organic Compounds
163
5.3.2 Extraction of Metals
170
5.3.3 Other Applications
173
5.4 Outlook
175
References
175
E. L. Byrne · M. Gilmore · L. Moura · M. Swadźba-Kwaśny · J. D. Holbrey (*)
The QUILL Research Centre, School of Chemistry and Chemical Engineering, Queen’s
University Belfast, Belfast, UK
e-mail: j.holbrey@qub.ac.uk
Abstract Hydrophobic deep eutectic solvents combine the typical, desirable features of deep eutectic solvents; inexpensive, benign, often naturally occurring components with high hydrogen bond-forming tendencies with hydrophobicity; and the
ability to form biphases with water. This implies an intrinsically challenging design,
where hydrophobicity is obtained in mixtures of components that can form hydrogen bonds and so have hydrophilic tendencies. Moreover, this is usually achieved
without resorting to the use of expensive perfluorinated components. This chapter
outlines design strategies of hydrophobic deep eutectic solvents, followed by an
overview of the key applications as extraction media for organic molecules from
fermentation broths and wastewater streams, metal ions from aqueous media, and
other uses including microextraction for analysis and CO 2 capture.
© The Editor(s) (if applicable) and The Author(s), under exclusive license to
Springer Nature Switzerland AG 2021
S. Fourmentin et al. (eds.), Deep Eutectic Solvents for Medicine, Gas
Solubilization and Extraction of Natural Substances, Environmental Chemistry
for a Sustainable World 56, https://doi.org/10.1007/978-3-030-53069-3_5
Chapter 5
Hydrophobic Deep Eutectic Solvents
Emily L. Byrne, Mark Gilmore, Leila Moura, Małgorzata Swadźba-Kwaśny,
and John D. Holbrey
Contents
5.1 Introduction
158
5.2 Design of Hydrophobic Deep Eutectic Solvents
158
5.2.1 From Hydrophobic Ionic Liquids to Hydrophobic Deep Eutectic Solvents
158
5.2.2 Hydrophobicity Through Organic Salts with Hydrophobic Hydrogen Bond
Donors
159
5.2.3 Losing the Salt, Abandoning the Hydrogen Bond Acceptor-Hydrogen Bond
Donor Strategy
161
5.3 Applications
163
5.3.1 Extraction of Organic Compounds
163
5.3.2 Extraction of Metals
170
5.3.3 Other Applications
173
5.4 Outlook
175
References
175
E. L. Byrne · M. Gilmore · L. Moura · M. Swadźba-Kwaśny · J. D. Holbrey (*)
The QUILL Research Centre, School of Chemistry and Chemical Engineering, Queen’s
University Belfast, Belfast, UK
e-mail: j.holbrey@qub.ac.uk
Abstract Hydrophobic deep eutectic solvents combine the typical, desirable features of deep eutectic solvents; inexpensive, benign, often naturally occurring components with high hydrogen bond-forming tendencies with hydrophobicity; and the
ability to form biphases with water. This implies an intrinsically challenging design,
where hydrophobicity is obtained in mixtures of components that can form hydrogen bonds and so have hydrophilic tendencies. Moreover, this is usually achieved
without resorting to the use of expensive perfluorinated components. This chapter
outlines design strategies of hydrophobic deep eutectic solvents, followed by an
overview of the key applications as extraction media for organic molecules from
fermentation broths and wastewater streams, metal ions from aqueous media, and
other uses including microextraction for analysis and CO 2 capture.