King Fahd University of Petroleum and Minerals (Saudi Arabia)
Date of Publication, Distribution, etc.
1996
PHYSICAL DESCRIPTION
Specific Material Designation and Extent of Item
175
DISSERTATION (THESIS) NOTE
Dissertation or thesis details and type of degree
M.S.
Body granting the degree
King Fahd University of Petroleum and Minerals (Saudi Arabia)
Text preceding or following the note
1996
SUMMARY OR ABSTRACT
Text of Note
New consistent mixture models for simple molecules were developed from the pair correlation functions and the virial coefficients for hard core molecules. These models use equations of state of pure fluids to predict properties of their mixtures. The developed models were tested for mixtures of additive hard spheres, non-additive hard spheres, Lennard-Jones and simple real fluids. The molecular parameter ranges used were (1) Hard sphere size ratio of 1 to 3 and packing fraction of 0.23 to 0.55, (2) Non-additive hard spheres with non-additivity parameter usd\Deltausd between 0.5 to 1.0 and reduced density between 0 to 1.3, (3) Lennard-Jones molecules with size and energy ratio from 1 to 2.0 and from 1 to 4.5 respectively. Binary mixtures of simple real molecules, argon-krypton, neon-argon, methane-carbon tetrafluoride and carbondioxide-ethane were also tested. Comparison of the predictions of the new models with simulation and experimental data shows a satisfactory agreement. Among all the new models, the one based on the expansion of pair correlation function is the most accurate. This model predicted compressibility factor for binary mixtures with errors of less than 1% for hard spheres, about 2% for Lennard-Jones and about 5% for the simple real molecules. A consistent mixture model was also developed for chain molecules. This was based on the consistency equations of the pair correlation function of Hamad (1994). The Tait equation of state for pure polymers was also extended to mixture of chain molecules. The extended Tait equation and the mixture model for chain molecules were used to predict the density of a binary mixture of poly(4-hydroxystyrene) and poly(vinylacetate). The mixture densities were predicted to within 1% of the experimental values. The mixture model for chain molecules is, in principle, also applicable to polymer solvent systems but cannot be used to predict phase separation.