Computational insights into deep eutectic solvent design: Modeling interactions and thermodynamic feasibility using choline chloride & glycerol

Abstract

To address climate change and environmental concerns, the chemical process industries are increasingly adopting green technology and exploring eco-friendly waste management practices. Deep Eutectic Solvents (DES) have emerged as promising green solvents with diverse applications in the industries in separation processes, catalysis, drug design, and a lot more. However, the ideal way for modeling ionic interactions within the hydrogen-bond acceptor (HBA) during DES synthesis remains uncertain, and theoretical insight on the formation mechanism of energetically stable DESs from choline chloride (CHL) and urea (URE) is yet to be explored. In this study, we investigate different modeling approaches (no bond, generic bond, or single bond) for ionic interactions in hydrogen-bond acceptor (HBA) molecules during DES synthesis and the thermodynamic feasibility of forming an energetically stable DES using choline chloride (CHL) and urea (URE) through theoretical calculations (PM3, HF, and DFT). Our findings indicate that the choice of modeling approach does not significantly affect the outcomes across calculation levels. The H-X DES formation pathway emerges as the most viable route for CHL: GLC DES synthesis, offering strong binding energy and high exothermicity. This pathway provides a robust solution for synthesizing energetically stable DES with potential applications in various industries. Researchers can consider alternative calculation levels when DFT becomes cost-prohibitive to optimize computational costs. Our study contributes valuable insights into DES design and synthesis, promoting environmentally sustainable and cost-effective processes.

Keywords

• Deep eutectic solvent
• Stability
• Semi-empirical
• DFT
• Materials