Solubility of N-Isopropylacrylamide in Carbon Dioxide

The solubility isotherms of N-isopropylacrylamide monomer (NIPAM) in supercritical carbon dioxide were obtained by the synthetic visual method in the temperature range of 304.8–353.0 K and the pressures range of 0.1–40.0 MPa, and the maximal solubility of NIPAM in CO₂ at these state parameters was determined. In addition, the region of crossover of isotherms P_mix = f(x) was detected, and the nature of this phenomenon was discussed. The predictive ability of the Chrastil model was assessed for this system.