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Preparation of Binary and Ternary Deep Eutectic Systems
Published on: October 31, 2019
What Determines the Eutectic Temperature for Ionic and Nonionic Acetamide Deep Eutectic Solvents? Entropy-Enthalpy
Rik N Mukherjee1,2, Pradip K Ghorai2, Ranjit Biswas1
1Chemical and Biological Sciences, Satyendra Nath Bose National Centre for Basic Sciences, Salt Lake, West Bengal, India.
Summary
This study presents a new theory to predict eutectic temperatures in deep eutectic solvents (DESs). The model accurately explains DES behavior by considering enthalpy and entropy, outperforming ideal solution models.
Area of Science:
- Physical Chemistry
- Materials Science
- Thermodynamics
Background:
- Deep eutectic solvents (DESs) are mixtures with unique properties.
- Understanding their phase behavior, particularly eutectic temperature, is crucial for applications.
- Existing models often fail to capture the complex interactions within DESs.
Purpose of the Study:
- To develop a theoretical formalism for predicting eutectic temperatures in DESs.
- To provide a thermodynamic explanation for non-ideal behavior in DESs.
- To investigate the influence of interparticle interactions on DES stability.
Main Methods:
- Separating enthalpic and entropic contributions to the free energy of mixing.
- Incorporating attractive and repulsive interactions into calculations.
- Utilizing simulated trajectories for enthalpy and two-phase thermodynamics for entropy.
- Examining five acetamide-based DESs with different co-formers.
Main Results:
- The developed theory accurately predicts eutectic temperatures for various DESs.
- The model explains negative deviations from ideal behavior by considering both attractive and repulsive forces.
- Enthalpy and entropy contributions were successfully quantified.
- The interplay between ionic and nonionic interactions dictates the dominant thermodynamic force (enthalpy or entropy).
Conclusions:
- The theoretical formalism provides a robust method for predicting DES eutectic temperatures.
- The theory elucidates the thermodynamic basis for the stabilization of DES liquid phases.
- This approach offers potential for predicting melting temperature-composition curves in binary DESs.
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