The Helmholtz free energy and grand potential of classical BINARY fluid MIXTURES are calculated. Only the direct correlation functions of the mixture are required. We follow Ebners functional expansion method to obtain the free energy and grand potential of a simple fluid and fluid MIXTURES. Later an exact expression for the Helmholtz free energy is obtained. As an example, the excess free energy per particle of simple and BINARY hard sphere fluid MIXTURES are calculated where the generalized mean spherical approximation (GMSA) for simple hard spheres and the Percus Yevick (PY) direct correlation function for both simple and BINARY hard sphere fluid MIXTURES are used. The results are compared with those obtained by Carnahan-Starling and Mansoori et al. respectively. We also apply the functional expansion to find the excess free energy per particle of BINARY hard disk MIXTURES and later compare the results with some other theories. In both cases the results agree well with the previously mentioned theories.

Dielectric constant measurements were made on BINARY MIXTURES of ethyl acetate (EA) and butyl acetate (BA) with the two amyl alcohols (iso-amyl alcohol (IAA) and tert-butyl alcohol (TBA)) for various concentrations at T = 298.2 K and in a frequency of 100 kHz. In order to obtain valuable information about heterogeneous interaction (interactions between the unlike molecules), the Kirkwood correlation factor, the Bruggeman dielectric factor and the excess permittivity were calculated.

In this paper, solubility of baclofen was studied by gravimetric method. The solubility of baclofen was measured in (water+1-hexyl-4-methylpyridinium bromide) BINARY MIXTURES from 293.1 K to 313.1 K under atmosphere pressure. In BINARY MIXTURES, the solubility increases with increasing ionic liquid concentration. This behavior probably is due to hydrophobic interaction between ACP and ionic liquid and formation of micelle. Indeed ionic liquid similar to the conventional cationic surfactants have tendency to associate as micelle structures. The main responsible to enhancement the solubility of baclofen in lower mass fraction is hydrophobic interaction between baclofen and ionic liquid. Whereas, in upper mass fractions of ionic liquid, beyond hydrophobic interactions, the formed micelles are another possible reason behind enhanced solubility of baclofen in aqueous solution of ionic liquid. The solubility data were fitted using modified Apelblat equation, and the semi-empirical lh equation. Both equations were shown a good applicability to prediction on solubility of baclofen in aqueous solutions of ionic liquid.

Polymerization of styrene in presence of two monofunctional initiators is studied kinetically in an ampoule scale. Polymerizations were ceased at different conversions for each ampoule while the temperature was increased almost linearly during the reaction. Three different initiator MIXTURES were used. The first MIXTURES were composed of benzoil peroxide (BPO) and t-butyl perbenzoate (TBPB) with various molar ratios and temperature programs. The second and third series were performed on MIXTURES of BPO and α,α'-azobisisobutyronitrile (AIBN) and AIBN with TBPB, respectively. The experimental results for these series revealed that increasing the percentage of TBPB in the initiator MIXTURES at the same reaction temperature intervals enhanced polymerization rate and molecular weight of the resulting polymers. On the other hand the results from the second series indicated that reducing AIBN in the mixture would have reduction effect on the reaction temperature intervals while both conversion and the polymer molecular weight are increased.

This work deals with estimation of temperature dependent BINARY interaction parameters (kij) for BINARY systems containing CO2 using the Soave-Redlich-Kwong equation of state with a group contribution method. In this paper six groups, namely CH3, CH2, CH, CH4 (methane), C2H6 (ethane), and CO2 (carbon dioxide) are defined and their relevant values of group interaction parameters are optimized. Using this method, it is possible to estimate the kij of any mixture containing carbon dioxide and hydrocarbons at any temperature along the coexistence curve. The results obtained in this study are, in most cases, accurate.

The molecular associations in the BINARY MIXTURES of (methanol/solvent), (ethanol/solvent) and (propanol/solvent) were studied using NMR, FTIR and VLE data at different temperatures. The activity coefficients as the most important quantities representing the mixture deviation form ideal behavior were evaluated by using various association models to express the physical and chemical contributions of the activity coefficients. The parameters of these models were calculated. The results indicated that for methanol and ethanol the dominant associated species are the tetramer whereas for propanol it is the trimer. The differences between the parameters of activity coefficient models were calculated by considering the physical and chemical contributions separately and were expressed in terms of residual parameters for the activity coefficient models. The parameters of van Laar model were corrected on the basis of the existing dominant species in the associated MIXTURES and a simple linear relation was obtained for the parameters of the model for the dominant species in terms of the parameters for monomer.

In the present work, the integral equations method is used to calculate transport properties of polar fluids. For this goal, we use the Stockmayer potential and examine theoretically the thermal conductivity of several refrigerant MIXTURES such as R125+R134a, R125+R32, R125+R152a, R134a+R32, R152a+R32, R134a+R143a, and R125+R143a. We solve numerically the Ornstein-Zernike (OZ) equation using the Hypernetted Chain (HNC) approximation for BINARY fluid MIXTURES and obtain the pair correlation functions. Finally, the temperature dependence of thermal conductivity is studied using Vesovic-Wakeham method and compared with available results.

Nucleate pool boiling heat transfer coefficient have been experimentally measured on a horizontal rod heater for various liquid BINARY MIXTURES. Measurements are based on more than three hundred data points on a wide range of concentrations and heat fluxes. In this investigation, it has been confirmed that the heat transfer coefficient in boiling solutions are regularly less than those in pure component liquids with same physical properties. Several reasons should be responsible for this phenomenon, but mainly it could be related to preferential evaporation of the more volatile component(s) during bubble formation. In this article, the performances of major existing correlations to the present experimental data including pure and BINARY mixture liquids are discussed. It is shown that it is impossible to predict the accurate value of boiling heat transfer for liquid MIXTURES and even pure liquids by any existing correlations over all ranges of concentrations or heat fluxes. In this investigation, the Schlunder correlation - as a model with excellent theoretical basis - has been modified; however some models provide superior performance in our experimental range. Originally, it is stated by different authors that B0 - the ratio of the interfacial area of heat transfer to those of mass transfer as a tuning parameters in Schlunder model - is too complicated to predict and should be fitted empirically as a function of heat flux, density and pressure for any given BINARY system. In this investigation, B0, the mentioned tuning parameter has been basically derived based on the analogy of the mass, heat and momentum transfer. As the results, the average error of Schlunder model in a wide range of boiling parameters has been significantly reduced.

The density and viscosity of three BINARY MIXTURES composed of methyl tert-butyl ether (MTBE) with 2-propanol, 2-butanol, and 2-pentanol over the whole composition range at 293. 15-323. 15 K were measured. The excess molar volume E V m and deviation in viscosity  η , were calculated and interpreted in terms of intermolecular interactions among the species in the MIXTURES. For all BINARY MIXTURES, negative values of E V m and  η were fitted to the Redlich-Kister polynomial function. By increasing temperature, E V m and  η were reduced and increased, respectively. The density of the BINARY systems was modeled in terms of the perturbed chain statistical associating fluid theory (PC-SAFT) and compared with the corresponding experimental data. Maximum of deviation between the experimental data and calculated values by this theory is 1. 4% and belongs to the MTBE + 2-butanol system.