A modified adjacency matrix was developed to delineate the chemical graph of a compound, in which the element aii along the diagonal of the matrix reflects the numbers of the lone-pair electrons and

The open-cell model equation of state (OCM EOS) proposed in the preceding paper by the authors has been extended to polymer-solvent and polymer blend systems, covering a variety properties, including P-V-T relations, the excess volume and enthalpy, the activity of solvents, and phase diagrams. Compared with the well-recognized Simha and Somcynsky EOS, the OCM EOS presents a better description of P-V-T relations and phase diagrams. Besides, through a set of proper binary interaction parameters, good correlation of the excess properties can be achieved. In conclusion, as an improvement over the existing hole theory EOSs, the OCM EOS is capable of describing liquid mixture properties with satisfactory accuracy.

The SAFT equation of state (EOS) combined with a one-parameter mixing rule was used to evaluate the capability of the SAFT approach for modeling the solubility of solid aromatic compounds in supercritical fluids (SCFs) with cosolvents. Binary interaction parameters were obtained by fitting the phase equilibrium data of the constituent binary systems. The SAFT EOS was used to predict the solubility of solids in carbon dioxide with cosolvents for five systems, and the overall average absolute relative deviation (AARD) was 20.43%. For the other 11 systems, the binary interaction parameters between the solids and the cosolvents were obtained by fitting the ternary solubility data, and the overall AARD was 16.45%. Comparison with the PRSV EOS showed that the SAFT EOS was superior in terms of both prediction and correlation. The present work demonstrates that the SAFT approach is useful for modeling the solubility of solids in SCFs with cosolvents with reasonable accuracy.

Based on White s renormalization group (RG) theory and the statistical associating fluid theory, a new equation of state (EOS) is derived, which can be used for a variety of fluids, including non-polar, polar and associating chain fluids both inside and outside the critical region. The new EOS, with the advantage of not introducing any additional adjustable parameter to the RG transform for real fluids, yields satisfactory critical exponent, vapor-liquid coexistence densities and vapor pressures, pVT isotherms, and isobaric specific heats for pure fluids. Especially, much better results are obtained than the original EOS in the nearest vicinity of the critical point.

In our previous work [J. Mi, C. Zhong, Yi.-G. Li, J. Chen, Chem. Phys., 305 (2004) 37-45], an equation of state (EOS) based on the combination of renormalization group theory (RG) and the statistical associating fluid theory (SAFT) was proposed for describing pure fluid thermodynamic properties both inside and outside critical region, which was extended to binary mixtures in this work. A variety of binary systems were considered in this work, including nonpolar/nonpolar, /polar, nonpolar/associating and associating/associating mixtures. Two adjustable parameters are required by the new EOS for each binary system, which are obtained by fitting the vapor-liquid equilibria (VLE) data at one emperature. The calculated results show that the new EOS gives satisfactory predictions for critical properties as well as the VLE at other temperatures, both inside and outside critical region. This work demonstrates that RG theory is a very useful tool for accurately describing fluid properties inside critical region, and a combination of it with SAFT EOS can lead to a new EOS possessing the advantages of both heories, applicable to the whole phase equilibrium region of binary mixtures.