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In the last 30 years, little experimental work has been reported on the critical properties of (halogenated hydrocarbon + hydrocarbon) mixtures. Furthermore, the overall amount of reported critical property data for these types of mixtures is quite small. This work aims to extended the existing data set and presents data on the critical temperatures of (i) 14 different chloroalkane (C3–C4) + hydrocarbon mixtures (C6–C7) as a function of mole fraction and (ii) 10 different aromatic halocarbons (chlorobenzene, fluorobenzene, 1,2-dichlorbenzene, or 1,3-dichlorobenzene) + alkanes (C8) as a function of mole fraction. All of the (gas + liquid) critical lines were continuous. Therefore, all mixtures displayed either Type I or Type II behavior.

This review is part 10 of a series of contributions by the critical properties group of the previous IUPAC Commission I.2 on Thermodynamics, Subcommittee on Thermodynamic Data and the present IUPAC Project #2000-026-1-100, Critical Compilation of Vapour Liquid Critical Properties, sponsored by the Physical and Biophysical Chemistry Division. It presents all known experimental data for the critical constants of hydrocarbons containing halogens. Recommendations are given together with uncertainties. Critical temperatures have been converted to ITS-90, and the molar masses are based on the relative atomic masses recommended by the IUPAC-CIAAW in 2005.

The mutual solubility and related liquid-liquid equilibria of C7 hydrocarbons with water and heavy water are exhaustively and critically reviewed. Reports of experimental determination of solubility in 23 chemically distinct binary systems that appeared in the primary literature prior to end of 2002 are compiled. For 9 systems sufficient data are available to allow critical evaluation. All data are expressed as mass percent and mole fraction as well as the originally reported units. In addition to the standard evaluation criteria used throughout the Solubility Data Series, a new method based on the evaluation of the all experimental data for a given homologous series of aliphatic and aromatic hydrocarbons was used.

The mutual solubility and related liquid–liquid equilibria of C6H14 hydrocarbons with water are exhaustively and critically reviewed. Reports of experimental determination of solubility in five chemically distinct binary systems that appeared in the primary literature prior to end of 2002 are compiled. For all five systems sufficient data are available to allow critical evaluation. All data are expressed as mass percent and mole fraction as well as the originally reported units. In addition to the standard evaluation criteria used throughout the Solubility Data Series, a new method based on the evaluation of the all experimental data for a given homologous series of saturated or unsaturated aliphatic hydrocarbons was used.

The mutual solubilities and related liquid-liquid equilibria of benzene with water and heavy water are exhaustively and critically reviewed. Reports of experimental determination of solubility in these two chemically distinct binary systems that appeared in the primary literature prior to end of 2002 are compiled. For the system benzene-water sufficient data are available to allow critical evaluation. All data are expressed as mass percent and mole fraction as well as the originally reported units. In addition to the standard evaluation criteria used throughout the Solubility Data Series, a new method based on the evaluation of all experimental data for a homologous series of aromatic hydrocarbons was used.

The literature has been searched through 2002 June for solubility data on the gases BF3, NF3, N2F4, SF6, CF4, CHF3, CH2F2, CH3F, C2F6, CHF5, 1,1,1,2-C2H2F4, 1,1,1-C2H3F3, 1,1-C2H4F2, CH5F, C3F8, c-C4F8, C2F4, 1,1-C2H2F2, C2H3F, C3F6, C3F6O, and SiF4 and the solids XeF6, XeF4, and XeF2 in all solvents. The data are compiled here. Where feasible evaluations have been carried out. The evaluations were mostly carried out for water as a solvent as the water systems are the most extensively studied. For other systems there is often only one set of measurement or two sets of measurements, which do not agree well. Evaluation of such systems will have to wait on more experimental measurements.

Previously, the investigation of the (gas + liquid) critical properties of (alkanol + alkane) mixtures has focussed on (primary alkanol + straight chain alkane) mixtures. The experimental data available for (alkanol + alkane) mixtures, which include secondary or tertiary alcohols and/or branched chain alkanes, are extremely limited. This work extends the existing body of data on (alkanol + alkane) mixtures to include mixtures containing these components. Here the (gas + liquid) critical temperatures of 29 {alkanol (C 2 –C 5 ) + alkane (C 5 –C 12 )} mixtures are reported. All the (gas + liquid) critical lines for the binary mixtures studied are continuous, indicating they obey either Type I or Type II phase behaviour.

Ethyne was probably first made in the laboratory by Edmund Davy in 1836. It was rediscovered nearly a quarter of a century later by Berthelot who gave it the name acetylene. Since that time ethyne has become a cheap raw material for the synthesis of organic materials and an important industrial fuel. A summary of the available solubility data for ethyne was published by Miller in 1965 [S. A Miller, Acetylene—Its Properties, Manufacture, and Uses (Academic, New York, 1965), Vol. I]. Many more data are now available in a wide range of research papers and patent applications. These data vary in their reliability. In the current work the data for systems included in Miller’s book have been reassessed and complemented by data published more recently. Literature has been surveyed to 1999. Data for a system may be unreliable unless two or more groups of workers have published values in close agreement. Where possible values of the mole fraction solubility at a partial pressure of 101.3 kPa have been tabulated. Equations have been given for the variation of mole fraction with temperature in cases in which values over a temperature range are available. The greater the number of independent sources of the data the more the reliance which can be placed on the utility of the resulting equation. Extrapolation of such equations beyond the temperature range of experimental measurements can lead to errors. In many of the systems it may be assumed that approximate values of the mole fraction solubility,x1, at a partial pressure of 101.3 kPa may be obtained by linear extrapolation of values for lower partial pressures,p1, on the assumption that x1/p1 is approximately constant. However a similar linear extrapolation of solubilities at pressures appreciably higher that 101.3 kPa to give mole fraction solubilities at 101.3 kPa can lead to gross errors. For the purpose of evaluation of data use has been made of the Krichevsky–Il’inskaya equation to obtain approximate values of solubilities at 101.3 kPa from measurements at higher pressures. These values were then compared with measurements made at or near to 101.3 kPa.

The (gas + liquid) critical temperature of a number of ethers, esters, and ketones are reported. These values, together with values reported by Quadri and Kudchadker, and Ambrose and co-workers provide a fully extended data set for the development of correlations for predicting the critical temperature of organic compounds containing carbon, hydrogen, and oxygen. Values reported here are compared with values reported in the literature, and it is concluded that many older values, on which a number of predictive correlations are based, are incorrect.

Infinite dilution activity coefficients (γ13∞) for mixtures of alkanes (C3–C8) in alkylcyclohexanes (C10–C18), and alkenes in alkylcyclohexanes (C10–C18), are reported. These were determined using gas–liquid chromatography where the alkylcyclohexanes form the stationary phase. A lattice theory for liquids, which has been previously applied to hydrocarbon mixtures, was used to calculate interchange energies from the experimental results. This theory was also applied to existing (cyclohexane+alkane) and (alkane+nonadecylcyclohexane) data with these interchange energies compared with values determined from the γ13∞results reported in this work. There was good agreement (1 to 5 per cent) between predicted and experimental γ13∞results for (alkane+alkylcyclohexane) mixtures. However, this was found not to be the case for the (alkene+alkylcyclohexane) mixtures where the alkene segment —CH=CH2was assumed to behave similarly to the —CH2—CH2— segment. The differences between experimental and theoretical γ13∞values for these types of mixtures were of the order of 30 per cent when using interchange energies derived from (alkane+alkylcyclohexane) mixtures.

Infinite dilution activity coefficients γ13∞and Henry's law constantsHfor mixtures of alkanes and Alkenes (C3to C6) in phenylalkanes (C10to C19) are reported. These were determined using gas-liquid chromatography (g.l.c.) A lattice theory for liquids, which has previously been applied to these types of mixtures, was used to calculate interchange energies from the experimental data. These were found to differ from those reported by previous workers. Good agreement (between 1 per cent and 5 per cent) was found between predicted and experimental γ13∞results for (alkane+phenylalkane). However, this was found not to be the case for the alkene+phenylalkane) when the alkene segment (−CH=CH2) was assumed to behave similarly to the −CH2−CH2−segment. The differences between experimental and theoretical γ13∞values for these types of mixtures were of the order of 30 per cent when using interchange energies derived from (alkane+phenylalkane).

Statistical moments have been widely used over the last 20 years to characterize the shape of chromatographic peak profiles. This work is concerned with testing the accuracy of the numerical integration method for determining statistical moments over a wide range of varying experimental conditions. Simulated peak profiles, whose moments can be calculated exactly from their mathematical functions, are used. Statistical moments measured using the numerical integration method are then compared with these mathematically exact results. Elution of low molecular weight hydrocarbons (C 1 -C 5 ) on a stationary phase of n-octadecane using gas-liquid chromatography is carried out, with statistical moments for these mixtures being determined from the experimental peak profiles using the numerical integration and exponentially modified Gaussian methods.

The gas−liquid critical temperatures of 23 alkenes (C5−C8), 8 amine compounds (C3−C8), and 8 cyclic hydrocarbons (C8−C10) are reported. These values, together with the previously reported critical temperatures for alkenes, amines, and cyclic hydrocarbons, provide extended data sets which can be used to develop more accurate correlations for predicting the critical temperatures of these alkene, amine, and cyclic hydrocarbon compounds. The majority of compounds whose critical temperatures are reported here have not been previously investigated.

The gas−liquid critical temperatures of 13 chlorinated alkanes (C3−C8) and 28 halogenated aromatic compounds (C6−C7) are reported. These values, together with the previously reported critical temperatures of about 140 other halogenated hydrocarbons, provide an extended data set which can be used to develop more accurate correlations for predicting the critical temperatures of halogenated hydrocarbon compounds. The majority of compounds whose critical temperatures are reported here have not been previously investigated.

Christou G., Sadus R.J. and Young C.L., 1991. Phase behaviour of 1-alkanol + alkane mixtures: gas-liquid critical temperatures. Fluid Phase Equilibria, 67: 259-271. The gas-liquid critical temperatures of several 1-alkanol and hydrocarbon mixtures are reported. The critical temperatures have also been calculated from the one-fluid model and the “hard sphere + attractive term” equation of state due to Guggenheim. The agreement is quite good for mixtures of similar-size molecules. The analysis provides values of an adjustable parameter, ξ, which reflects the strength of unlike intermolecular interaction. The values of ξ are discussed in terms of the influence of hydrogen bonding and dipole forces. Mixtures in which hydrogen bonding and dipole forces are important have ξ values which are less than would otherwise be expected. The deviation of the experimental critical temperatures from linearity between the critical temperatures of the two pure components is discussed qualitatively. The observed deviations are consistent with expected effects of the dipolar interactions and the difference in critical temperature of the pure components.

Christou, G., Young, C.L. and Svejda, P., 1991. Gas-liquid critical temperatures of mixtures of propane, butane, pentane, sulfur hexafluoride, dichlorodifluoromethane and chlorotri-fluoromethane with less volatile compounds of a range of varying polarities. Fluid Phase Equilibria, 67: 45-53.

As part of an extensive study of the gas—liquid critical properties of binary mixtures the present paper reports critical temperature measurements on mixtures of polydimethylsiloxanes including tetrakis(trimethylsiloxy)silane, with a range of quasi-spherical molecules. This work considerably extends studies undertaken by one of us over a decade ago. The siloxanes offer the opportunity to study the critical properties of simple chain, cyclic or quasi-spherical molecules over a considerably greater range of molecular weight than is possible with hydrocarbons. Values of the interaction parameter, ξ, were obtained from the experimental results using the hard-sphere + attractive force one-fluid model. These interaction parameters, which in some measure, at least, reflect the relative strength of the interaction between pairs of unlike molecules, are compared with values from previous measurements on related systems. The interaction parameters obtained by fitting theory to experiment are also compared with values predicted using the relationship proposed recently by Sadus. The agreement, is, in general fairly good although not within the experimental uncertainty.

The one fluid model together with the hard sphere equation of state due to Guggenheim was used to calculate the solubility of argon, xenon, krypton, nitrogen, carbon monoxide, carbon tetrafluoride, sulphur hexafluoride, methane, ethane and propane in various alkanes (C 5 –C 30 ) at a partial pressure of 1 atm and typically between 280 and 350 K. The agreement between theory and experiment is generally quite good. The ξ values obtained from the analysis reflect the strength of intermolecular interaction between unlike molecules.

27 were presented in English by scientists from the Czech Republic, France, Germany, Hungary, Italy, Japan, Russia, Turkey, Taiwan, and Slovakia. The plenary and contributed lectures were presented by eminent scientist and by well-known active researchers of younger generations. The Symposium featured a dynamic poster section which included presentations by many participants, especially young scientists, and was accompanied by very lively discussions. A short account on the materials presented at the Symposium was published in the Book of Abstracts. Regrettably, this volume does not cover all the new and interesting results presented at the Symposium since not all the authors were able to present their lectures for publication in this volume (some of the material had been published earlier or submitted elsewhere). However, it provides a good representation of the scope of the meeting and the main topics of the discussion. The symposium focused on current developments in the radical polymerization in the micellar media and synthesis of novel (surface-active) polymer products. It attracted an excellent attendance, reflecting the strong and wide-spread interest in the field of preparation of non-conventional polymer dispersions and stimulated mutual interactions between researchers working on similar display technologies. Both an interesting venue of the conference and well-organized scientific and social program added to the success of the event as quoted by participants. This brief review of the materials of the Symposium including those presented in this volume shows that the main interest in the investigation of the preparation of non-traditional polymer dispersions and polymer products lies in the nature of the reaction loci, particle nucleation, and particle-growth events.

This volume is an update of the Solubility Data Series Volume 7 published in 1981 on oxygen and ozone. For this volume, the literature was covered from 1981 to 2009 with some papers from 2010. Some earlier papers missed in the 1981 volume are included. Interest in the solubility of oxygen and of ozone continues to be high. The solubility of oxygen in water at low pressure seems well established, but more work is needed on the solubility of oxygen in water at high pressure and high temperature. There is now a wealth of salt-effect data on the solubility in aqueous salt solutions, but some glaring discrepancies still exist. Little has been done on salt effects at high pressure and high temperature. The solubility data of oxygen in hydrocarbons seem sparse. The solubility of oxygen in alcohols through C5 seems well established. Between the 1981 volume and this volume, there are solubility data in over 70 fluorocarbons and fluorocarbon compounds with O, H, S, and N. A new area is the solubility of oxygen in ionic liquids, which are becoming increasingly important as replacement solvents for volatile organic solvents. Information on the solubility of ozone in water, aqueous solutions and organic liquids has also been updated.

This is part 9 of a series of contributions by the critical properties group of the previous IUPAC Commission I.2 on Thermodynamics, Subcommittee on Thermodynamic Data and the present IUPAC Project, Critical Compilation of Vapour Liquid Critical Properties, sponsored by the Physical and Biophysical Division. It presents all known experimental data for the critical constants of organic hydrocarbon compounds containing nitrogen. Recommendations are given together with uncertainties.

The critical temperatures of several ternary mixtures containing hydrocarbons, acetone, acetonitrile and propylcyanide are reported. A Newton-Raphson procedure and a general solution for solving the criticality conditions of ternary mixtures using the one-fluid model and the Guggenhiem equation of state are outlined. The critical temperatures of the three related binary mixtures were used to obtain the three unlike interaction parameters so that no additional parameters were needed to calculate the critical temperatures of the ternary mixtures. Agreement between experiment and theory is, in general, quite good.

The phase diagrams for carbon dioxide + n-alkanes (C1-C20) have been constructed for the one fluid model using both the van der Waals and Guggenheim equations of state by the techniques described in a previous paper. Various combining rules for calculating the volume and energy parameters characterising interactions between unlike molecules have been used. Comparison between theory and experiment suggest that the interaction parameter ξ is slightly greater than that calculated from the Hudson and McCoubrey combining rule. This is consistent with conclusions reached from an analysis of other thermodynamic properties.

A computer program has been developed to calculate the critical properties of binary mixtures from Deiters' equation of state. The critical properties of over 50 binary mixtures of permanent gases, alkanes, benzene and alkanes, cyclohexane and alkanes, and acetone and hydrocarbons have been calculated. The Guggenheim equation has also been used to enable comparison with a simple “hard sphere + attractive term” equation. Deiters′ equation gives good results for mixtures of moderately different size molecules whereas Guggenheim's equation is superior for dissimilar size molecules. The values of an interaction paramter, ξ, obtained from our analysis are also reported.

The upper critical solution temperatures, UCST, of a number of mixtures of simple organic substances, including C 5 to C 10 alkanes, with sulphur hexafluoride are reported. These UCST are analysed in terms of the one fluid model in order to estimate an interaction parameter, ξ, which is a measure of the strength of the interactions between sulphur hexafluoride+organic molecule. The values of ξ are discussed briefly. Several of the systems studied exhibited the barotropic phenomenon.

The upper critical solution temperatures of perfluoromethylcyclohexane + n-alkanes (C5 to C15) have been measured. The results have been compared with the van der Waals one fluid model using the Guggenheim equation of state and employing the technique for solving the criticality conditions described previously. The energy parameter, ξ, defined by the equation ξ=Tc12/(Tc11Tc22)½(where Tcij is the energy reducing parameter characterising interactions between molecules of species i and j) needed to fit the experimental UCST data have been calculated. The value of ξ is always less than unity and decreases with an increase in the chain length of the n-alkane. Similar trends have been previously observed for values of ξ obtained from gas–liquid critical points of mixtures of hexafluorobenzene + n-alkanes and perfluoron-heptane + n-alkanes. Possible explanations of such trends are suggested.

The classical mathematical description of critical points of binary mixtures and the computer technique used to solve the relevant equations are described. The techniques used here are applicable to any closed equation of state and one fluid model prescription.The critical points, in a given range of temperature and volume are located as the solution of two simultaneous equations: (∂p/∂v)T,x(∂2G/∂x22)T,p= 0 (∂p/∂v)T,x(∂3G/∂x32)T,p= 0 with reduced volume v and reduced temperature T as independent variables. The search procedure consists of three parts. Firstly the zeros of the first quantity are established around the perimeter of an area in the v, T plane defined by the range of v and T. Secondly the locus of the zeros of this quantity are tracked by a novel stepping procedure. The sign of the second quantity is determined at each step, a change in sign indicating that a zero and hence a critical point has just been passed. Thirdly, the critical point is accurately located by a bisection technique.Examples of the loci for mixtures are given and the critical points obtained compared with those obtained by Scott and van Konynenburg for the van der Waals equation of state.Tests for the stability of critical phases which can be applied to analytic expressions for derivatives of the free energy with respect to composition of a mixture are described.The tests are applied so that if a firm decision is made at any point between material stability, metastability and unstability the sequence of tests ends. Initially tests for mechanical stability are applied and points which are mechanically stable are subjected to further tests to determine whether the critical phase is materially stable, metastable or unstable.If (∂4G/∂x42)p,T is negative the critical phase is materially unstable otherwise a detailed study of the (∂2G/∂x22)p,T against composition diagram is needed. In the more difficult cases numerical integration of the area under the (∂2G/∂x22)p,T against composition curve has to be undertaken. The determination of stability for systems in which (∂2G/∂x22)p,T against composition diagram has multiple interacting loops is also described.

The gas-liquid critical temperatures of mixtures of alkanes, aromatic hydrocarbons, hexafluorobenzene, and tetrachloromethane with some ethers have been measured. The strength of the interaction between pairs of unlike molecules in the mixture have been estimated from the results using the one-fluid model and an equation of state which incorporates a hard-sphere term and an attractive term. It is concluded that there may be a small enhanced interaction between the ethers and aromatic hydrocarbons or aromatic fluorocarbons. Analysis of the critical temperatures indicates that enhanced interactions are very small for aliphatic ethers and slightly larger, but still small, for cyclic ethers: tetrahydrofuran, and 1,4-dioxan.

The use of recently developed equations of state for critical phenomena is examined. Deiters' equation is incapable of accurately predicting the gas-liquid critical properties of mixtures of dissimilar size molecules whereas a hard convex body equation does not yield significantly better results than a simple hard sphere equation. In many cases a ‘hard sphere + attractive term’ equation can predict the critical properties of Type II mixtures to within experimental error. This conclusion is valid for a wide range of component molecules. However, an adjustable parameter is usually required to optimise agreement. Type II liquid-liquid properties can also be accurately calculated but the same precision can not be obtained for Type III phenomena. Some calculations for CHF 3 + alkane mixtures are reported which exhibited Type III behaviour. It appears that the most significant improvement in a priori prediction of critical phenomena lies in developing better combining rules rather than ‘improved’ equations of state. Work on ternary critical phenomena has hitherto been largely limited to simple gas-liquid properties which are continuous with respect to composition. In this work the critical properties of CF 4 + CHF 3 + CH 4 over a wide range of temperature and pressure are calculated. The results illustrate the potential of theory to classify the phase behaviour of ternary mixtures.

Christou, G., Morrow, T., Sadus, R.J. and Young, C.L., 1986. Phase behaviour of fluoro-carbon and hydrocarbon mixtures: interpretation of type II and type III behaviour in terms of a ‘hard-sphere + attractive force’ equation of state. Fluid Phase Equilibria , 25: 263–272. Experimental measurements of the upper critical solution temperature of octadecafluorooctane + n -alkanes are reported. These measurements and those discussed by Schneider (1983) on the phase behaviour of tetrafluoromethane + alkanes are compared with results obtained from the one-fluid model using a ‘hard sphere + attractive term’ equation of state. Interaction parameters, ξ, obtained from the comparison together with values from the literature on other fluorocarbon + hydrocarbon mixtures show trends which are briefly discussed.

The critical properties of hydrocarbon mixtures, perfluorocarbon + hydrocarbon, perfluoromethylcyclohexane + siloxane, acetone + hydrocarbon and polydimethyl siloxane mixtures have been calculated from an equation of state for hard convex bodies and from Guggenheim's equation of state for hard spheres. In general, the results of both equations agree well with experimental data. It appears, however, that taking shape factors into account (by using the hard convex body equation) does not lead to a significant improvement in the agreement between theory and experiment for the critical properties.

An attempt has been made to predict gas–gas immiscibility using the Guggenheim and van der Walls equations of state. The stability conditions have been solved, using a digital computer, for the van der Waals one fluid model. The computational aspects have been discussed in previous papers in this series.The Guggenheim equation of state successfully predicts gas–gas immiscibility of the correct kind for most of the systems which have been studied experimentally. In contrast the van der Waals equation of state predicts the correct kind of gas–gas immiscibility in only a very few cases.The applicability of the model is briefly discussed.

Upper critical solution temperatures of nitromethane and alkanes, and alkanenitriles and alkanes have been used to obtain a parameter, ψ, characterising the interaction between the pairs of unlike molecules in the mixture. Values of ψ have been calculated using a “hard sphere and attractive force” equation of state together with the van der Waal's one fluid model. Values of ψ obtained for the ethanenitrile and alkane mixtures have been compared with those obtained from an analysis of gas—liquid critical temperatures. There is a discrepancy of several percent between the values calculated from the two properties.

The critical temperatures of some ternary siloxane mixtures are reported. The critical temperatures of binary perfluoromethylcyclohexane and siloxane mixtures were also measured. The results are compared to values calculated by solving the critical conditions from conformal solution theory using the one-fluid model, the ideal mixing equation and the Guggenheim equation of state. The agreement is good for mixtures of similar sized molecules whereas the agreement for dissimilar sized molecules is somewhat inadequate.

Gas-liquid critical pressures of mixtures of octamethylcyclotetrasiloxane with neopentane, 2,3-dimethylbutane, cyclopentane and tetramethylsilane, critical temperatures of octamethylcyclotetra-siloxane + tetramethylsilane mixtures and the vapour pressure of tetramethylsilane near the critical region are reported. The critical temperature and pressure data for these and other mixtures are compared with values calculated from the van der Waals one fluid theory assuming different combining rules and equations of state. The limitations of the criticality condition solutions are discussed briefly.