The eutectic point in choline chloride and ethylene glycol mixtures. Issue 91 (31st October 2022)

• Record Type: Journal Article
• Authors: Hayler, Hannah J.; Perkin, Susan
• Is Part Of: Chemical communications. Volume 58:Issue 91(2022)
• Page Start: 12728
• Page End: 12731
• Publication Date: 2022-10-31
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1039/d2cc04008e
• Languages: English
• ISSNs: 1359-7345

Abstract

Abstract : We present measurements that contrast the reported eutectic point of choline chloride and ethylene glycol mixtures, and confirm the non-deep and non-1:2 nature of the eutectic point. Abstract : The choline chloride (ChCl) and ethylene glycol (EG) mixture has become established as a paradigmatic deep eutectic solvent (DES). Here, we present measurements of the phase behaviour of this mixture over a wide composition range, and provide an extended phase diagram. The eutectic point was found to lie at −28 ± 1 °C and 0.01 < x ChCl < 0.02, sharply contrasting with the previously expected eutectic composition. Our observations confirm that the eutectic temperature is not 'deep' compared to the ideal solution theory prediction. We also observe a cold-crystallisation at T = −65 °C which may have been formerly misinterpreted as the eutectic point.