Molecular dynamics simulation of solubility of C.I. Disperse Brown 19 in supercritical CO2 and water

In order to explore the solubility differences of disperse dyes in supercritical CO2 and water under their dyeing conditions, the solvation free energy and the binding free energy of C.I. Disperse Brown 19 in these two solvents were syudied, based on the molecular dynamics simulation, using thermodynamic integration method respectively, and the weak interaction between dye molecules and solvent molecules was examined by average noncovalent interaction method. The results showed that the absolute values of free energy of C.I. Disperse Brown 19 dye molecules in supercritical CO2 (24 MPa, 130℃) and water (0.25 MPa, 130℃) were small, whereas the absolute value of solvation free energy in supercritical CO2 was slightly less than that in water, and the absolute value of binding free energy was slightly greater than in water. The interactions (van der Waals force) between C.I. Disperse Brown 19 dye molecules and supercritical CO2 molecules and water molecules were both weak and unstable, and,the interactions between the dye molecule and the supercritical CO2 molecules were more unstable than that with water molecules. Copyright No content may be reproduced or abridged without authorization.