Solvatochromic parameters and solubilities in supercritical fluid systems

O’Neill, Mark L.; Kruus, Peeter; Burk, Robert

doi:10.1139/v93-229

Cited by 22 publications

(16 citation statements)

References 17 publications

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“…With similar indicators and conditions, the λ m values of the pure MeOH (Table S2) and the π* values of binary scCO 2 –MeOH mixtures (Figure S9) were in accordance with the literature values , within the uncertainty of the measurements. Due to variation in indicator types, the π* values of pure CO 2 (Figure S10a) averaged from two indicators were lower than those literature values measured from the 2-nitroanisole indicator, , while the π* values showed a good agreement with the values obtained from the Nile red indicator (Figure S10b). …”

Section: Results and Discussionsupporting

confidence: 87%

“…A comparison between the experimental λ m and π* data with the literature values was made for pure CO 2 , ,, pure methanol (MeOH) cosolvent, and binary scCO 2 –MeOH mixtures . With similar indicators and conditions, the λ m values of the pure MeOH (Table S2) and the π* values of binary scCO 2 –MeOH mixtures (Figure S9) were in accordance with the literature values , within the uncertainty of the measurements.…”

Section: Results and Discussionsupporting

confidence: 77%

“…37 Industrial & Engineering Chemistry Research binary scCO 2 −MeOH mixtures (Figure S9) were in accordance with the literature values 27,33 within the uncertainty of the measurements. Due to variation in indicator types, the π* values of pure CO 2 (Figure S10a) averaged from two indicators were lower than those literature values measured from the 2-nitroanisole indicator, 22,60 while the π* values showed a good agreement with the values obtained from the Nile red indicator (Figure S10b). 48 To confirm variation in pure CO 2 , the averaged π* values measured in this work were compared with the literature π* values averaged from 10 indicators, 23 (i) Pressure and temperature dependences of π*.…”

Section: Methodsmentioning

confidence: 97%

“…A comparison between the experimental λ m and π* data with the literature values was made for pure CO 2 , 22,48,60 pure methanol (MeOH) cosolvent, 27 and binary scCO 2 −MeOH mixtures. 33 With similar indicators and conditions, the λ m values of the pure MeOH (Table S2) and the π* values of ) as a function of pure CO 2 density (ρ CO 2 ) estimated from four methods: fluorescence (red solid line, eq 7), Raman (blue solid line, eq 8), UV−vis (orange solid line, eq 9), and molecular dynamics (MD) simulations (dashed line, eq 10).…”

Section: Methodsmentioning

confidence: 99%

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Kamlet–Taft Dipolarity/Polarizability of Binary Mixtures of Supercritical Carbon Dioxide with Cosolvents: Measurement, Prediction, and Applications in Separation Processes

Duereh

Sugimoto

Ota

et al. 2020

Ind. Eng. Chem. Res.

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A flow-type apparatus and predictive framework were developed for measuring and estimating dipolarity/ polarizability (π*) values of binary mixtures of supercritical carbon dioxide (scCO 2 )−cosolvents. The π* values of scCO 2 with methanol and ethanol cosolvents (up to 10 mol %) are reported at the temperature ranging from 40 to 80 °C and pressure ranging from 10 to 20 MPa and were found to be dependent on fluid density. The predictive framework for scCO 2 −cosolvent mixtures proposed in this work was the modification by the addition of correction functions (g(ρ CO 2 )) of local density enhancement into the previous predictive framework for binary liquid nonpolar−polar mixtures [Ind. Eng. Chem. Res. 2019, 58, 18986−18996]. Four g(ρ CO 2 ) forms with a function of CO 2 density were evaluated by considering literature local density enhancements of pure CO 2 obtained from (i) fluorescence, (ii) Raman, (ii) UV−vis spectroscopic techniques, and (iv) molecular dynamics simulations. The framework was applied to the prediction of π* of four scCO 2 −cosolvent mixtures (methanol, ethanol, 2-propanol, and 1,1,1,2tetrafluoroethane (HFC134a)) and was found to give a reliable value with an overall relative deviation of 0.03 between the experimental and calculated data, where the fluorescence g(ρ CO 2 ) function provided a lower deviation than the other three functions. The application of the framework to separation processes showed that the π* values were found to explain the trends of solubility, extraction yield, and fractionation recovery. The π* values determined from the framework can be used to analyze solvent effect trends in many separation processes that required only cosolvent dipole moment, pure π* component, and CO 2 density (pressure and temperature).

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Section: Results and Discussionsupporting

confidence: 87%

Section: Results and Discussionsupporting

confidence: 77%

Section: Methodsmentioning

confidence: 97%

Section: Methodsmentioning

confidence: 99%

See 2 more Smart Citations

Kamlet–Taft Dipolarity/Polarizability of Binary Mixtures of Supercritical Carbon Dioxide with Cosolvents: Measurement, Prediction, and Applications in Separation Processes

Duereh

Sugimoto

Ota

et al. 2020

Ind. Eng. Chem. Res.

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“…For supercritical CO 2 , π*, β and E N T all increase with pressure. Increasing temperature causes π* and β to decrease 74,[108][109][110] and has little effect on the E N T of scCO 2 . 111 CO 2 -expanded liquids 34 have solvatochromic parameters that are functions of both temperature and CO 2 pressure.…”

Section: Molecular Solventsmentioning

confidence: 99%

Solvatochromic parameters for solvents of interest in green chemistry

et al. 2012

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Solvatochromic data have been collected from the literature or newly measured for 83 molecular solvents, 18 switchable solvents, and 187 ionic liquids that have been cited in the green chemistry literature. The data include the normalized Reichardt's parameter (E N T ), the Nile red λ max , and the Kamlet-Taft parameters (α, β, and π*). Disagreements within the literature about the properties of glycerol and poly (ethylene glycol) have been resolved with new data. The switching of a switchable-polarity solvent (also known as a reversible ionic liquid) by CO 2 causes a significant increase in polarity/polarizability (π*) but no change in the basicity (β). A switchable-hydrophilicity solvent undergoes an even greater change in polarity because it merges with an aqueous phase upon exposure to CO 2 . Trends observed from the data of ionic liquids are presented, along with concerns about the best method for determining the Kamlet-Taft parameters.

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Supercritical Phase Catalysis—Heterogeneous

Subramaniam¹,

Ford²

2010

Encyclopedia of Catalysis

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The potential applications of supercritical reaction media in heterogeneous catalysis have greatly expanded in recent years to include industrially significant reactions such as selective catalytic oxidations (fine and agricultural chemicals), fixed‐bed hydrogenations (pharmaceuticals, chemical intermediates), polymerizations, hydroformylations (petrochemical), and solid‐acid catalyzed alkylations (petroleum refining). The near‐critical region (roughly 1.05‐1.2 Tc; and 0.9 ‐ 2.0 Pc) provides access to unique fluid properties (liquid‐like densities and gas‐like transport properties) that have been exploited in heterogeneous catalytic systems in numerous ways such as these: eliminating oxygen or hydrogen solubility limitations in the liquid phase of multiphase reaction systems; enhanced desorption and transport of heavy molecules (such as coke precursors) in mesoporous catalysts alleviating pore‐diffusion limitations and improving catalyst effectiveness; in situ removal of primary reaction products maximizing their selectivity; enhanced heat capacity ameliorating the problem of parametric sensitivity in exothermic fixed‐bed reactors; and facile separation of reactants and products. Supercritical reaction systems are thus excellent examples of the ‘multifunctional reactor’ concept. This chapter provides an overview of recent advances in each of these areas including fundamental and experimental aspects. Barriers and challenges confronting application of CO2‐based processes in industrial catalysis, and advances in overcoming these barriers are highlighted.

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Solvatochromic parameters and solubilities in supercritical fluid systems

Cited by 22 publications

References 17 publications

Kamlet–Taft Dipolarity/Polarizability of Binary Mixtures of Supercritical Carbon Dioxide with Cosolvents: Measurement, Prediction, and Applications in Separation Processes

Kamlet–Taft Dipolarity/Polarizability of Binary Mixtures of Supercritical Carbon Dioxide with Cosolvents: Measurement, Prediction, and Applications in Separation Processes

Solvatochromic parameters for solvents of interest in green chemistry

Supercritical Phase Catalysis—Heterogeneous

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