An interfacial equation of state based on perturbation theory for surfactant-oil-water system has been developed. By combining the interfacial equation of state with Boudh-Hir and Mansoori's model, a molecular the...An interfacial equation of state based on perturbation theory for surfactant-oil-water system has been developed. By combining the interfacial equation of state with Boudh-Hir and Mansoori's model, a molecular ther-modynamic model has been proposed. The interfacial tension of surfactant-oil-water systems can be calculated from the surface tensions of pure oil and water by this model. The interfacial tension data for sodium dodecyl sulphate-heptane-water system, polyoxyethylene n-octylphenol-heptane-water system and hexadecyl trimethyl ammonium bromide-heptane-water system have been correlated. By using the adjustable parameters obtained, the interfacial tensions of these systems at other temperatures have been predicted. Both the correlated and the predicted values are satisfactory.展开更多
The density functional theory, simplified by the local density approximation and mean-field approxi-mation, is applied to study the surface properties of pure non-polar fluids. A reasonable long rang correction is ado...The density functional theory, simplified by the local density approximation and mean-field approxi-mation, is applied to study the surface properties of pure non-polar fluids. A reasonable long rang correction is adopted to avoid the truncation of the potential. The perturbation theory is applied to establish the equation for the phase equilibrium, in which the hard-core chain fluid is as the reference fluid and the Yukawa potential is used as the perturbation term. Three parameters, ε/κ, d and ms, are regressed frorn the vapor-liquid equilibria, and the surface properties, including density profile, surface tension and local surface tension profile are predicted with these parameters.展开更多
A molecular dynamics simulation model is established based on the well-known Lennard-Jones 12-6 potential function to determine the surface tension of a Lennard-Jones liquid-vapor interface. The simulation is carried ...A molecular dynamics simulation model is established based on the well-known Lennard-Jones 12-6 potential function to determine the surface tension of a Lennard-Jones liquid-vapor interface. The simulation is carried out with argon as the working fluid of a given molecular number at different temperature and different truncated radius. It is found that the surface tension of a Lennard-Jones fluid is likely to be bigger for a bigger truncated radius, and tends to be constant after the truncated radius increased to a certain value. It is also found that the surface tension becomes smaller as the temperature increases.展开更多
基金Supported by the National Nature Science Foundation of China(No.29736170)
文摘An interfacial equation of state based on perturbation theory for surfactant-oil-water system has been developed. By combining the interfacial equation of state with Boudh-Hir and Mansoori's model, a molecular ther-modynamic model has been proposed. The interfacial tension of surfactant-oil-water systems can be calculated from the surface tensions of pure oil and water by this model. The interfacial tension data for sodium dodecyl sulphate-heptane-water system, polyoxyethylene n-octylphenol-heptane-water system and hexadecyl trimethyl ammonium bromide-heptane-water system have been correlated. By using the adjustable parameters obtained, the interfacial tensions of these systems at other temperatures have been predicted. Both the correlated and the predicted values are satisfactory.
基金Supported by the National Natural Science Foundation of China (No. 20102007) and the Fundamental Research Fund of Tsinghua University of China (No. JZ2002003).
文摘The density functional theory, simplified by the local density approximation and mean-field approxi-mation, is applied to study the surface properties of pure non-polar fluids. A reasonable long rang correction is adopted to avoid the truncation of the potential. The perturbation theory is applied to establish the equation for the phase equilibrium, in which the hard-core chain fluid is as the reference fluid and the Yukawa potential is used as the perturbation term. Three parameters, ε/κ, d and ms, are regressed frorn the vapor-liquid equilibria, and the surface properties, including density profile, surface tension and local surface tension profile are predicted with these parameters.
基金Funded by the National Natural Science Foundation of China (No.50076048)
文摘A molecular dynamics simulation model is established based on the well-known Lennard-Jones 12-6 potential function to determine the surface tension of a Lennard-Jones liquid-vapor interface. The simulation is carried out with argon as the working fluid of a given molecular number at different temperature and different truncated radius. It is found that the surface tension of a Lennard-Jones fluid is likely to be bigger for a bigger truncated radius, and tends to be constant after the truncated radius increased to a certain value. It is also found that the surface tension becomes smaller as the temperature increases.
