Physical properties of seven deep eutectic solvents based on l-proline or betaine. (April 2019)

• Record Type: Journal Article
• Authors: Sánchez, Pablo B.; González, Begoña; Salgado, Josefa; José Parajó, Juan; Domínguez, Ángeles
• Is Part Of: Journal of chemical thermodynamics. Volume 131(2019)
• Page Start: 517
• Page End: 523
• Publication Date: 2019-04
• Subjects: DES -- Betaine -- l-Proline -- Physical properties; Thermodynamics -- Periodicals; Thermochemistry -- Periodicals; Thermodynamique -- Périodiques; Thermochimie -- Périodiques; Thermochemistry; Thermodynamics; Periodicals; 541.369
• DOI: 10.1016/j.jct.2018.12.017
• Languages: English
• ISSNs: 0021-9614

Abstract

Highlights: Seven deep eutectic solvents formed by betaine orl -proline andld -levulinic acid or citric acid or lactic acid were prepared. Density, viscosity, speed of sound and refractive index of the seven DES were measured from 293.15 K to 343.15 K. Coefficient of thermal expansion, isentropic compressibility and molar refraction were calculated from experimental data. The thermal behavior of the prepared DES was studied by differential scanning calorimetry and thermogravimetric analysis. Abstract: Density, ρ, refractive index, nD, speed of sound, u, and viscosity, η, of the betaine + dl -lactic acid (1:2), betaine + dl -lactic acid (1:5), betaine + dl -lactic acid-water (1:1:1), betaine-levulinic acid (1:2), betaine-citric acid-water (2:1:6), l -proline + levulinic acid (1:2) andl -proline + dl -lactic acid (1:1) deep eutectic solvents were measured at several temperatures from 293.15 K to 343.15 K and at atmospheric pressure. From the experimental data, coefficients of thermal expansion, α, isentropic compressibility, ks, and molar refraction, Rm, were calculated. Moreover the thermal behavior of these DESs, from glass transition to degradation temperature, was studied by differential scanning calorimetry and thermogravimetric analysis.