Solubilization Of Oxymatrine In Supercritical Carbon Dioxide Microemulsion

This paper reviewed the theory of extraction technology using microemulsion in supercritical carbon dioxide (SC-CO2). Progress in surfactant selection, research methods and application of microemulsion in SC-CO₂ has also been summarized.The solubility of oxymatrine in pure SC-CO₂ was measured using flow type method in the range of pressure 11 to 21 MPa, at temperature 308.15, 318.15 and 328.15 K, respectively. Under above conditions, the maximum solubility was 1.13×10^-2 mg/mLCO₂ (2.46×10^-6 mol/mol), the minimum solubility was 1.85×l0^-3 mg/mLCO₂ (6.81×10^-7 mol/mol). At constant temperature, the solubility of oxymatrine increased with the pressure, then became leveled.The homogeneous region in the PFPE/Water/CO₂ system was determined. The cloud point pressure increased with the temperature when water content was constant, and it increased with the water content at constant temperature.A static experimental apparatus used to research the solubilization of strong polarity substances in microemulsion has been improved. The feasibility of the apparatus was tested using naphthalene, and compared with literature.The solubilization of oxymatrine in PFPE/Water/CO₂ system was the major part in the thesis. According to the results, we found that the microemulsion in SC-CO₂ could solubilizate oxymatrine. The kinetics of solubilization was very complicated. It went up quickly then down to a constant value. When the surfactant concentration was about 2.6%, the density of CO₂ was about 0.82 g/mL, the W₀ vablue was in the range of 10～20 mol/mol and the temperature was in the range of 318.15～338.15 K, the solubilization values increased with the increase of W₀ and temperature. The pressure had little effect on solubilization. The water's polarity in microemulsion was less than that in common water.