Understanding ion-ion and ion-urea interactions in mixtures of urea and choline oxyanions salts

Author(s)

de Souza, Icaro F. T. ; Ribeiro, Mauro C. C.

• Document type: Journal article
• Source: JOURNAL OF MOLECULAR LIQUIDS; v. 379, p. 9-pg., 2023-03-22.

Abstract

Rotational and oscillatory rheology, Raman, and infrared spectroscopy were used to examine the anion effect on the structure of deep eutectic solvents (DES) by contrasting reline (the 1:2 mixture of choline chloride and urea, [Chol]Cl:U) with other mixtures at the same composition based on oxyanion salts of different acceptor and donor characteristics for hydrogen bonding (choline acetate, [Chol][Ac], and choline dihydrogen phosphate, [Chol][DHP]). Oscillatory rheological measurements of [Chol][DHP] suggest the presence of hydrogen-bonded [DHP] chains that can be broken and recombined. Far-infrared spectra also show that [Chol][DHP] has stiffer dynamics when compared to the other two mixtures under investigation. The high-frequency range of the vibrational spectra provides further proof of differences in the hydrogen bond strengths across the systems under study. The fingerprint region of the vibrational spectra provides information about [Chol] and urea conformations in the presence of different anions in the liquid phase. (c) 2023 Elsevier B.V. All rights reserved. (AU)

• FAPESP's process: 17/23051-0 - Phase transitions, structure, and rheology of ionic liquids
• Grantee: Ícaro Francescato Tavares de Souza
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• FAPESP's process: 16/21070-5 - Vibrational spectroscopy with spatial resolution
• Grantee: Mauro Carlos Costa Ribeiro
• Support Opportunities: Research Projects - Thematic Grants