Thermodynamics Research Center / ThermoML | Thermochimica Acta

Experimental solubility and thermodynamic aspects of methylene blue in different solvents

Salimi, Anis, Roosta, Aliakbar
Thermochim. Acta 2019, 675, 134-139
ABSTRACT
The solubility of methylene blue in methanol, ethanol, 2-propanol, acetone, ethyl acetate, and water was measured at 303.15 K and 0.1 MPa. The solubility of methylene blue in ethyl acetate was very low while the solubility in methanol and 2-propanol was very high and not precisely measurable. In addition, the effect of temperature on the solubility of methylene blue in ethanol, acetone, and water was measured in the temperature range of 278.15 K-318.15 K. The solubility data was modeled with the electrolyte activity model of symmetric e-NRTL. The overall AARD of the model was obtained to be 2.32%. According to the results, there is a good agreement between the experimental solubility data and the solubility estimated with the help of the electrolyte activity model. Furthermore, the solubility data were used to estimate the enthalpy of fusion and melting point of methylene blue, as well as the enthalpy of dissolution and heat capacity for the dissolution of methylene blue in ethanol, acetone, and water.
Compounds
# Formula Name
1 C16H18ClN3S 3,7-bis(dimethylamino)phenothiazin-5-ium chloride
2 C2H6O ethanol
3 CH4O methanol
4 C3H8O propan-2-ol
5 C3H6O acetone
6 C4H8O2 ethyl acetate
7 H2O water
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
  • 3
  • Mass concentration, kg/m3 - 1 ; Liquid
  • Temperature, K; Liquid
  • Pressure, kPa; Liquid
  • Liquid
  • Crystal - 1
  • UV spectrophotometry
  • 1
  • POMD
  • 1
  • 4
  • Mass concentration, kg/m3 - 1 ; Liquid
  • Temperature, K; Liquid
  • Pressure, kPa; Liquid
  • Liquid
  • Crystal - 1
  • UV spectrophotometry
  • 1
  • POMD
  • 1
  • 6
  • Mass concentration, kg/m3 - 1 ; Liquid
  • Temperature, K; Liquid
  • Pressure, kPa; Liquid
  • Liquid
  • Crystal - 1
  • UV spectrophotometry
  • 1
  • POMD
  • 1
  • 7
  • Mole fraction - 1 ; Liquid
  • Temperature, K; Liquid
  • Pressure, kPa; Liquid
  • Liquid
  • Crystal of intercomponent compound 1
  • UV spectrophotometry
  • 9
  • POMD
  • 1
  • 7
  • Mass density, kg/m3 ; Liquid
  • Temperature, K; Liquid
  • Pressure, kPa; Liquid
  • Liquid
  • Crystal - 1
  • Pycnometric method
  • 9
  • POMD
  • 1
  • 2
  • Mole fraction - 1 ; Liquid
  • Temperature, K; Liquid
  • Pressure, kPa; Liquid
  • Liquid
  • Crystal - 1
  • UV spectrophotometry
  • 9
  • POMD
  • 1
  • 2
  • Mass density, kg/m3 ; Liquid
  • Temperature, K; Liquid
  • Pressure, kPa; Liquid
  • Liquid
  • Crystal - 1
  • Pycnometric method
  • 9
  • POMD
  • 1
  • 5
  • Mole fraction - 1 ; Liquid
  • Temperature, K; Liquid
  • Pressure, kPa; Liquid
  • Liquid
  • Crystal - 1
  • UV spectrophotometry
  • 9
  • POMD
  • 1
  • 5
  • Mass density, kg/m3 ; Liquid
  • Temperature, K; Liquid
  • Pressure, kPa; Liquid
  • Liquid
  • Crystal - 1
  • Pycnometric method
  • 9