Solubility of C. I. Disperse Red 60 and C. I. Disperse Blue 60 in supercritical carbon dioxide

Solubility of two disperse dyes (C. I. Disperse Red 60 and C. I. Disperse B lue 60) in supercritical carbon dioxide was measured at pressures up to 35 MPa and temperatures between 313 K and 423 K in a closed-loop equilibrium a pparatus equipped with a magnetic pump. The solubility increased with press ure at the same temperature. Solubility isotherms were straight and paralle l to each other when the logarithm of solubility was plotted versus density of the fluid, whereas the slope of each isotherm decreased with increasing temperature when it was plotted versus the logarithm of density. The exper imental data were successfully correlated using two semiempirical equations .