Thermodynamics Research Center, ThermoML : Journal of Chemical and Engineering Data

Thermal Properties of Choline Chloride/Urea System Studied under Moisture-Free Atmosphere

Gilmore, M.[Mark], Swadzba-Kwasny, M.[Malgorzata], Holbrey, J. D.[John D.]
J. Chem. Eng. Data 2019, 64, 12, 5248-5255
ABSTRACT
Physical chemistry of an archetypal deep eutectic solvent system, choline chloride:urea, was studied using dry components under moisture-free conditions. The phase diagram reveals that the eutectic melting point is 304.95 K (higher than any of the previously reported values to date), and a previously-unrecognised phase region in the solid-liquid phase diagram, corresponding to a C1.C2 transition (351.15 K) from a-choline chloride to ss-choline chloride. Viscosities and densities, measured for the eutectic composition as a function of temperature, were compared with all data available in the literature, and discrepancies are discussed. Thermal stability studies reveal that the eutectic composition undergoes a thermal decomposition at temperatures as low as 363.15 K (mass loss rate of 0.411 wt% h-1), which calls for a careful consideration when using these solvents at elevated temperatures.
Compounds
# Formula Name
1 C5H14ClNO choline chloride
2 CH4N2O urea
Datasets
The table above is generated from the ThermoML associated json file (link above). POMD and RXND refer to PureOrMixture and Reaction Datasets. The compound numbers are included in properties, variables, and phases, if specificied; the numbers refer to the table of compounds on the left.
Type Compound-# Property Variable Constraint Phase Method #Points
  • POMD
  • 1
  • Triple point temperature, K ; Crystal 2
  • Crystal 2
  • Crystal 1
  • Air at 1 atmosphere
  • VISOBS
  • 1
  • POMD
  • 1
  • Molar enthalpy of transition or fusion, kJ/mol ; Crystal 2
  • Crystal 2
  • Crystal 1
  • Air at 1 atmosphere
  • DSC
  • 1
  • POMD
  • 1
  • 2
  • Eutectic temperature, K ; Liquid
  • Pressure, kPa; Liquid
  • Liquid
  • Crystal 2 - 1
  • Crystal - 2
  • visual
  • 1
  • POMD
  • 1
  • 2
  • Solid-liquid equilibrium temperature, K ; Liquid
  • Mole fraction - 1; Liquid
  • Pressure, kPa; Liquid
  • Liquid
  • Crystal - 2
  • VISOBS
  • 3
  • POMD
  • 1
  • 2
  • Solid-liquid equilibrium temperature, K ; Liquid
  • Mole fraction - 1; Liquid
  • Pressure, kPa; Liquid
  • Liquid
  • Crystal 2 - 1
  • VISOBS
  • 2
  • POMD
  • 1
  • 2
  • Viscosity, Pa*s ; Liquid
  • Temperature, K; Liquid
  • Pressure, kPa; Liquid
  • Mole fraction - 1; Liquid
  • Liquid
  • Cone and plate viscometry
  • 13
  • POMD
  • 1
  • 2
  • Mass density, kg/m3 ; Liquid
  • Temperature, K; Liquid
  • Pressure, kPa; Liquid
  • Mole fraction - 1; Liquid
  • Liquid
  • Vibrating tube method
  • 8