当压力或温度超过临界值时,此状态的CO2就称为超临界CO2流体,那么超临界流体随温度的变化CO2流体的密度是怎样变化的

图1-1.超临界流体的压力–温度相图
Fig.1-1.Schematic pressure-temperature phase diagram for a pure component showing the supercritical fluid (SCF) region.The triple point (T) and critical point (C) are marked.The blue circles represent the variation in density of the substance in the different regions of the phase diagram.Note that the density varies continuously between the liquid state and the gas state,providing that the liquid-gas equilibrium line (T-C) is not crossed.[15]
图1-2.超临界二氧化碳物理（密度和传输）性质的可调节性
Fig.1-2.Pressure-tunability of density and transport properties of supercritical fluids in the near-critical region.[16]
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[15] Cooper A.I.Polymer synthesis and processing using supercritical carbon dioxide [J].J.Mater.Chem.,2000,10:207-234.[16] Subramaniam B.Enhancing the stability of porous catalysts with supercritical reaction media [J].Applied Catalysis A:General,2001,212:199-213.