Microstructure of Deep Eutectic Solvents: Current Understanding and Challenges

Abstract

In the past decade, researchers have put forth a lot of efforts to conceive a precise structural arrangement and properties of deep eutectic solvents (DESs) that provide designer pathways in order to broaden the application domain of these solvents. However, these contributions are limited to a few experimental and computational techniques. In this review, we have encompassed experimental techniques employed to establish the structure−property relationship of bulk DESs along with recent growth witnessed in this domain from a computational perspective. The nanostructuring plays an important role in various task specific applications of DESs. These solvents are found to exhibit unique heterogeneity at nanolength scales, the origin of which is unique and primarily depends on the constituent species involved. The hygroscopic nature of some DESs makes it crucial to explore the structural anatomy of hydrated DESs. Hence, this opens another subdomain to explore the impact of hydration on the bulk microscopic structure of DES and to know whether the nature is destructuring or structuring with respect to the neat solvents. This review highlights the recent successes attained in developing a thorough bulk microstructural understanding of neat and hydrated DESs.

Deep eutectics and analogues as electrolytes in batteries

“…Notably, DESs are multicomponent systems originating from the combination of ionic and molecular species, and their liquid state relies on a more structurally complex network with contributions from dominant hydrogen bonding plus electrostatic or van der Waals forces, rather than only electrostatic forces between anion and cation as in the case of conventional ILs. 24,26 Being the electrochemical field one of the most trodden paths for IL application, it is easy to understand that, soon after they apparition on the scientific scene, DESs were suggested as alternative electrolytes in energy storage systems and this sector is now progressing at a rapid pace. The remarkable increase in the level of interest in DES electrolytes for batteries is illustrated by the rapid growth in the number of publications on the topic over the period 2012 to 2021 (Fig.…”

Computer Simulations of Deep Eutectic Solvents. Challenges, Solutions, and Perspectives

“…Some computational studies have been discussed in reviews devoted to current DES applications. For example, Kaur et al [32] reviewed the research on microstructure and devoted part of the review to simulations of DES structures. Pelaquim et al [16], Liu et al [15], and Shama et al [33] have provided overviews of studies devoted to modeling gas solubility in DESs.…”

Computer Simulations of Deep Eutectic Solvents: Challenges, Solutions, and Perspectives

“…Some computational studies have been discussed in reviews devoted to current DES applications. For example, Kaur et al [ 39 ] reviewed the research on microstructure and devoted part of the review to simulations of DES structures. Pelaquim et al [ 17 ], Liu et al [ 16 ], and Shama et al [ 40 ] have provided overviews of studies devoted to modeling gas solubility in DESs.…”