The pendent drop or standing bubble method is applied to measure the interfacial tensions between water and nonpolar fluids (n-hexane, n-heptane, nitrogen, oxygen and methane)up to 473K and 220MPa. The high pressure a...The pendent drop or standing bubble method is applied to measure the interfacial tensions between water and nonpolar fluids (n-hexane, n-heptane, nitrogen, oxygen and methane)up to 473K and 220MPa. The high pressure autoclave with t wo visual windows and the auxiliary equipment are described. The sizes(ca 2mm) and shapes of drops or bubbles are recorded with microscope and video camera. The use of digital image permits fast, precise determination of the contour parameters. The densit y values of the liquids or gases have been chosen from literature.A special program is proposed to calculate the interfacial tensions automatically from drop shape at given temperature and pressure. The interfacial tensions σ12 increase with pr essure for the twoliquid-liquid systems,but decrease with pressure for the three gas-liquid systems.展开更多
A rational equation of state of the perturbation type with a repulsion and attraction term has been applied to reproduce critical curves of six different binary systems up to high temperatures and pressures. A square ...A rational equation of state of the perturbation type with a repulsion and attraction term has been applied to reproduce critical curves of six different binary systems up to high temperatures and pressures. A square well potential for intermolecular interaction is used. With pairwise combination rules for these potentials three adjustable parameters are needed. The experimental critical point and phase equilibrium data are compared with the values predicted using the equation of state. Good agreement is obtained for the analysis of the critical pressure composition data and molar volumes.展开更多
文摘The pendent drop or standing bubble method is applied to measure the interfacial tensions between water and nonpolar fluids (n-hexane, n-heptane, nitrogen, oxygen and methane)up to 473K and 220MPa. The high pressure autoclave with t wo visual windows and the auxiliary equipment are described. The sizes(ca 2mm) and shapes of drops or bubbles are recorded with microscope and video camera. The use of digital image permits fast, precise determination of the contour parameters. The densit y values of the liquids or gases have been chosen from literature.A special program is proposed to calculate the interfacial tensions automatically from drop shape at given temperature and pressure. The interfacial tensions σ12 increase with pr essure for the twoliquid-liquid systems,but decrease with pressure for the three gas-liquid systems.
文摘A rational equation of state of the perturbation type with a repulsion and attraction term has been applied to reproduce critical curves of six different binary systems up to high temperatures and pressures. A square well potential for intermolecular interaction is used. With pairwise combination rules for these potentials three adjustable parameters are needed. The experimental critical point and phase equilibrium data are compared with the values predicted using the equation of state. Good agreement is obtained for the analysis of the critical pressure composition data and molar volumes.
