版权所有：华东理工大学物理化学教研室 26 2). Carbon dioxide The experimental phase diagram for carbon dioxide. 6.3 Three typical phase diagrams Triple point: T3=216.8K(p=5.11atm) Critical point Tc=674.30K(p=72.9atm) Normal boiling point Tb=194.7K(p=1.0atm)
版权所有：华东理工大学物理化学教研室 26 2). Carbon dioxide The experimental phase diagram for carbon dioxide. 6.3 Three typical phase diagrams Triple point: T3=216.8K(p=5.11atm) Critical point Tc=674.30K(p=72.9atm) Normal boiling point Tb=194.7K(p=1.0atm)
版权所有：华东理工大学物理化学教研室 27 2). Carbon dioxide 6.3 Three typical phase diagrams The positive slope of the solidliquid boundary, which indicates that the melting temperature of solid carbon dioxide rises as the pressure is increased. The triple point lies above 1 atm, the liquid cannot exist at normal atmospheric pressures whatever the temperature. The solid sublimes when left in the open - 'dry ice'. The experimental phase diagram for carbon dioxide
版权所有：华东理工大学物理化学教研室 27 2). Carbon dioxide 6.3 Three typical phase diagrams The positive slope of the solidliquid boundary, which indicates that the melting temperature of solid carbon dioxide rises as the pressure is increased. The triple point lies above 1 atm, the liquid cannot exist at normal atmospheric pressures whatever the temperature. The solid sublimes when left in the open - 'dry ice'. The experimental phase diagram for carbon dioxide
版权所有：华东理工大学物理化学教研室 28 6.3 Three typical phase diagrams 2). Carbon dioxide Supercritical CO2 (compressed CO2 above Tc) is used in supercritical fluid chromatography (SFC), a form of chromatography in which the supercritical fluid is used as the mobile phase. A more m u n d a n e a p p l i c a t i o n o f supercritical carbon dioxide is in the extraction. The experimental phase diagram for carbon dioxide
版权所有：华东理工大学物理化学教研室 28 6.3 Three typical phase diagrams 2). Carbon dioxide Supercritical CO2 (compressed CO2 above Tc) is used in supercritical fluid chromatography (SFC), a form of chromatography in which the supercritical fluid is used as the mobile phase. A more m u n d a n e a p p l i c a t i o n o f supercritical carbon dioxide is in the extraction. The experimental phase diagram for carbon dioxide
版权所有：华东理工大学物理化学教研室 29 3). The helium The phase diagram for 4He 6.3 Three typical phase diagrams Triple point: Tλ=2.17K Normal boiling point: Tb=4.22K Critical point: Tc=674.30K
版权所有：华东理工大学物理化学教研室 29 3). The helium The phase diagram for 4He 6.3 Three typical phase diagrams Triple point: Tλ=2.17K Normal boiling point: Tb=4.22K Critical point: Tc=674.30K
版权所有：华东理工大学物理化学教研室 30 3). The helium The phase diagram for helium Helium behaves unusually at low T: the solid and gas phases are never in equilibrium however low the temperature. Solid helium can be obtained only by applying pressure over 20 bar. The pure helium has a liquid-liquid phase transition at its λ-line. The liquid phase marked He- Ⅰbehaves like a normal liquid; the other phase, He-Ⅱ, is a superfluid. It is so called because it flows without viscosity. 6.3 Three typical phase diagrams
版权所有：华东理工大学物理化学教研室 30 3). The helium The phase diagram for helium Helium behaves unusually at low T: the solid and gas phases are never in equilibrium however low the temperature. Solid helium can be obtained only by applying pressure over 20 bar. The pure helium has a liquid-liquid phase transition at its λ-line. The liquid phase marked He- Ⅰbehaves like a normal liquid; the other phase, He-Ⅱ, is a superfluid. It is so called because it flows without viscosity. 6.3 Three typical phase diagrams