第四章绿色溶剂（The fourth chapter green solvent）.docVIP

第四章绿色溶剂（The fourth chapter green solvent） - one of the hot topics of green chemistry means green solvent of supercritical fluid in the In the In the In the In the supercritical fluid rate SCF exergy refers to material temperature and pressure respectively at the critical temperature A special part above and above the critical pressure Fluid state. Supercritical Fluid) pressure /MPaO A C supercritical fluid Tc=31.06 Temperature /oC Pc=7.38 solid The phase diagram of liquid gas CO2 is higher than critical temperature and critical point Near the critical point State called supercritical state. He is in a supercritical state in gas-liquid two-phase flow is very close in nature So that it is impossible to tell. In 1822, Cagniard first reported rate of critical phenomena of material. In 1879 Hanny and Hogarth found that the rate of supercritical fluid on solid solubility rate provides a basis for the application of supercritical fluid. 1970 Zosel coffee beans from the extraction rate by sc-CO2 extraction technology Because the rate from supercritical fluid development enters a new stage. In 1992, Desimone first reported the rate of supercritical sc-CO2 as solvent rate The polymerization rate rate polymer molecular weight of 270 thousand to create a super Pro Bound CO2 is a precursor of polymer synthesis. Physical characteristic density (g/cm3), viscosity (g/cm/s), diffusion coefficient (cm2/s), gas (0.2-2) * 10-3 (1-4) * 10-40.1-0.4 liquid 0.6-1.6 (0.2-3) x 10-2 (0.2-2) * 10-5SCF 0.2-0.9 (1-9) * 10-4 (0.2-0.7) * 10-3SCF transfer characteristics and gas in the liquid in the liquid density comparison of 1 similar and solvation ability is very strong in the pressure and temperature of small changes can cause the changes of density 2 changes in pressure and temperature can change phase change 3 viscosity, diffusion coefficient close to the gas, has a strong transfer performance And the moving speed of the 4 dielectric constant in the polarizability and the molecular behavior