Ann-Sofi M. Kauppila

Thermochemical Investigations of Hydrogen-Bonded Solutions. Part 9. Comparison of Mobile Order Theory and the Kretschmer-Wiebe Association Model for Predicting Pyrene Solubilities in Binary Alcohol + Alcohol Solvent Mixtures

A relatively simple expression is developed for predicting the solubility of an inert crystalline solute in binary alcohol + alcohol solvent mixtures based upon the Kretschmer-Wiebe association model. The predictive accuracy of the newly-derived expression is compared to equation(s) derived previously from Mobile Order theory. Computations show that both models accurately describe the solubility behavior of pyrene in the 24 binary solvent systems studied. Average absolute deviations between observed and predicted values were 2.0% and 2.2% for the Kretschmer-Wiebe and Mobile Order predictive equations, respectively.

Prediction of anthracene solubility in alcohol + alkane solvent mixtures using binary alcohol + alkane VLE data. Comparison of Kretschmer-Wiebe and mobile order models

Abstract The abilities of two association models to predict anthracene solubilities in a number of binary alkane + alcohol solvent mixtures are compared. For each alkane + alcohol system, parameters in the Kretschmer-Wiebe and mobile order models were obtained from binary vapor-liquid equilibrium data. These parameters were then used, along with measured solubilities of anthracene in the pure alcohol and pure alkane, to predict solubilities of anthracene in the alkane + alcohol mixtures. To increase the number of systems available for analysis, new solubility data were measured at 298.15 K for anthracene in mixtures of n-heptane with 1-pentanol, 2-pentanol, and 2-methyl-2-butanol and for mixtures of n-hexane with 1-pentanol. New total pressure data at 303.15 K were obtained for n-heptane + 1-butanol and n-heptane + 2-butanol. Combining literature data with those reported here results in twenty binary alkane + alcohol systems for which both VLE data and anthracene solubilities are available. Upon fitting to the VLE data, the Kretschmer-Wiebe and mobile order models were found to represent equilibrium pressures with root mean square deviations of 0.13 and 0.19 kPa, respectively. Solubilities of anthracene in alkane + alcohol mixtures were predicted with average deviations of 2.8% and 4.7%, respectively.

Solubility of anthracene in binary alcohol + 1-pentanol solvent mixtures at 25°C: Comparison of expressions derived from Mobile Order theory and the Kretschmer-Wiebe association model

A relatively simple expression is developed for predicting the solubility of an inert crystalline solute in binary alcohol + alcohol solvent mixtures based upon the Kretschmer-Wiebe association model. The predictive accuracy of the newlyderived expression is compared to equation(s) derived previously from Mobile Order theory using experimental anthracene solubilities in seven binary alcohol + 1-pentanol solvent mixtures at 25°C, which were measured as part of the present investigation. Computations show that both models accurately describe the solubility behavior of anthracene in the binary solvent systems studied. Average absolute deviations between observed and predicted values were 0.9% and 1.4% for the Kretschmer-Wiebe and Mobile Order predictive equations, respectively.

Thermochemical investigations of hydrogen-bonded solutions. Part 11. Expressions for predicting anthracene solubilities in alcohol + alkoxyalcohol mixtures based on Mobile Order theory

Experimental solubilities are reported for anthracene dissolved in eight binary mixtures containing 2-ethoxyethanol with 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-methyl-1-propanol, 1-pentanol, 3-methyl-1-butanol and 1-octanol, and also in binary 1-pentanol+2-methoxyethanol and 2-methyl-1-propanol+2-propoxyethanol solvent systems at 25°C. Results of these measurements, combined with previously reported anthracene solubility data in 22 different alcohol +2-alkoxyethanol (2-methoxyethanol, 2-propoxyethanol and 2-butoxyethanol) solvent mixtures, are used to test the limitations and applications of expressions derived from Mobile Order theory. The first predictive expression assumes only formation of homogeneous self-associated hydrogen-bonded species, whereas the second equation includes additional terms to account for heterogeneous complex formation between the dissolved alcohol and 2-alkoxyethanol solvent molecules. Both equations predict the observed anthracene solubilities to within an average absolute deviation of about 3%.

Spectrochemical investigations of fluorescence quenching agents: Part 5. Effect of surfactants on the ability of nitromethane to selectively quench fluorescence emission of alternant PAHs

Applicability of the nitromethane selective quenching rule for discriminating between alternant vs. nonalternant polycyclic aromatic hydrocarbons (PAHs) is examined for 18 representative PAH solutes dissolved in micellar cetyltrimethylammonium chloride (CTACl), micellar dodecyltrimethylammonium bromide (DTAB), micellar Brij-35 and micellar sodium octanoate (SO) solvent media. Experimental results show that nitromethane quenched fluorescence emission of only the 10 alternant PAHs in the two cationic (CTACl and DTAB) and nonionic Brij-35 surfactant solvent media as expected. Emission intensities of nonalternant PAHs, except for the few exceptions noted previously, were unaffected by nitromethane addition. Unexpected quenching behavior was observed, however, in the case of nonalternant PAHs dissolved in micellar sodium octanoate solvent media. Nitromethane quenched fluorescence emission of all nonalternant PAHs studied in the SO solvent media, which is contrary to the selective quenching rule.

Thermochemical investigations of hydrogen-bonded solutions. Part 10. Development of expression for predicting excess enthalpies of ternary two alcohol + inert hydrocarbon systems based upon mobile order theory

The unconventional solution model of mobile order theory, which has previously been shown to provide a very accurate thermodynamic description of anthracene and pyrene solubilities and chemical potentials in binary alcohol + alcohol solvent mixtures, is extended to other thermodynamic excess functions. An expression is derived for predicting excess molar enthalpies of ternary inert hydrocarbon + two alcohol systems from measured binary data. Applications and limitations of the newly derived predictive expression are assessed using published enthalpy data for 11 ternary alkane + 1-alcohol + 1-alcohol systems.

Solubility of benzil in binary alkane + cyclooctane solvent mixtures : Comparison of predictive expressions derived from the nearly ideal binary solvent (NIBS) model

Abstract Experimental solubilities are reported for benzil dissolved in seven binary mixtures containing cyclooctane with n-hexane, n-heptane, n-octane, n-nonane, methylcyclohexane, 2,2,4-trimethylpentane, and tert-butyl-cyclohexane at 25°C. Results of measurements are compared to the predictions of equations developed previously for solubility in systems of nonspecific interactions. The most successful equation in terms of goodness of fit involved a volume fraction average of the excess Gibbs free energies relative to the Flory-Huggins model, and predicted the experimental solubilities in the seven systems studied to within an overall average absolute deviation of 2.1% and with a maximum deviation of 3.6%.

Solubility of benzil in binary alkane + dibutyl ether solvent mixtures. Comparison of predictive expressions derived from the nearly ideal binary solvent model

Experimental solubilities are reported for benzil dissolved in six binary mixtures containing dibutyl ether with hexane, heptane, octane, cyclohexane, methylcyclohexane, and 2,2,4-trimethylpentane at 25°C. Results of these measurements are compared to the predictions of equations developed previously for solubility in systems of nonspecific interactions. The most successful equation in terms of goodness of fit involved a volume fraction average of the excess Gibbs energies relative to the Flory-Huggins model, and predicted the experimental solubilities in the six systems studied to within an overall average absolute deviation of 3.4% and with a maximum deviation of 6.0%.