Molecular thermodynamics of solute‐polymer‐supercritical fluid systems

Shim, Jae‐Jin; Johnston, Keith P.

doi:10.1002/aic.690370414

Cited by 66 publications

(78 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…1 increase even if the CO 2 is not removed. This efMoreover, solubility and diffusivity in glassy polyfect has been exploited to help extract impurities meric materials can be quite sensitive to the confrom [6][7][8] and introduce additives in 9 polymeric macentration of the sorbed species, especially highly terials. soluble species such as CO 2 .…”

Section: Introductionmentioning

confidence: 99%

Direct measurement of the carbon dioxide-induced glass transition depression in a family of substituted polycarbonates

Banerjee

Lipscomb

1998

J. Appl. Polym. Sci.

View full text Add to dashboard Cite

: We present a method for the direct measurement of the glass transition temperature of compressed gas-polymer systems. The technique utilizes a Setaram C80D microcalorimeter equipped with high-pressure cells. Pressurizing the cells and running in scanning mode allows direct determination of the glass transition temperature. To validate the method, T g measurements of the CO 2 -poly(methyl methacrylate) system as a function of gas phase pressure were made. The results compare favorably with literature values. However, the effects of foaming appear to interfere with T g measurement at the highest gas pressures. The CO 2 -induced T g depression of a series of polycarbonates was also measured. The magnitude of the T g depression increases with decreasing glass transition temperature, reflecting an increase in intrinsic chain mobility, as evidenced by the glass transition temperature. The data correlate well with the Chow model.

show abstract

Section: Introductionmentioning

confidence: 99%

Direct measurement of the carbon dioxide-induced glass transition depression in a family of substituted polycarbonates

Banerjee

Lipscomb

1998

J. Appl. Polym. Sci.

View full text Add to dashboard Cite

show abstract

“…2. Since the ability of scCO 2 to swell polymers is enhanced by increasing the CO 2 pressure [14][15][16] and this would make the movement of the substrates toward the catalytic species inside the polymer easier, one can expect that the overall reaction rate increases with the pressure and this enhancement may cancel the dilution effect. However, this explanation is not plausible, because similar effects of CO 2 pressure were observed even for the hydroformylation in scCO 2 using homogeneous complex catalysts [17,18].…”

Section: Methodsmentioning

confidence: 99%

Hydroformylation of 1-hexene using polymer-supported rhodium catalysts in supercritical carbon dioxide

Fujita

Akihara

Fujisawa

et al. 2007

Journal of Molecular Catalysis A: Chemical

View full text Add to dashboard Cite

Hydroformylation of 1-hexene was carried out in supercritical CO 2 (scCO 2 ) and in organic solvents (toluene and ethyl acetate) using polymer-supported rhodium catalysts, which were prepared from polystyrene bound triphenylphosphine (TPP) and dicarbonylacetylecetonato rhodium. Preparation variables such as TPP/Rh ratio, time of rhodium precursor fixation on the support and time of syngas pretreatment do not indicate significant effects on the reaction. The product distribution slightly changes with CO 2 pressure. It increases appreciably as H pressure is raised in scCO but CO retards the reaction. The influence of H 2 2 2 pressure in scCO 2 is slightly different from that in toluene. Changes of the structure of rhodium complexes on the polymer during the catalyst preparation and the reaction were investigated by diffuse reflectance FT-IR. It should be noted that the catalyst is recyclable for the reaction in scCO 2 and the reaction rate and selectivity of the hydroformylation are much higher than those in the organic solvents.

show abstract

“…In most of the above-cited models for the pressure and temperature effects on SFC retention, the effect of swelling has been ignored although its importance has already been emphasized in the early studies on high-pressure GC [127-1311. With a specific reference to SFC, the effect of swelling on solute retention has been taken into account in the unified molecular theory of both partition [105,132] and adsorption [133-1351 chromatography, and in several treatments employing classical thermodynamics [76,77,88,90,91]. The unified molecular theory of chromatography is based on a mean-field lattice-gas model comprising the approximation of random mixing.…”

Section: Enhancement Factors Brown Et Al [71]mentioning

confidence: 99%

Diffusion and thermodynamic measurements by supercritical fluid chromatography

Roth

1991

J Microcolumn Separations

View full text Add to dashboard Cite

Abstract. Applications of supercritical fluid chromatography (SFC) to physicochemical measurements are reviewed. Emphasis is laid on the determination of binary diffusion coefficients at infmite dilution of solutes in supercritical solvents, and on actual or potential applications of SFC to the measurements of thermodynamic quantities in dilute, binary, supercritical mixtures. Physicochemical measurements emerge as a specific application field of SFC with many links to transport phenomena and to molecular thermodynamics of fluid-phase equilibria. Key words: supercritical fluid chromatography, d i p i v i t y measurements, diDsioncoescients, thermodynamic measurements, dilute supercritical mixtures

show abstract

Molecular thermodynamics of solute‐polymer‐supercritical fluid systems

Abstract: The distribution coefficients of the solutes (toluene, naphthalene, and phenanthrene)

Cited by 66 publications

References 31 publications

Direct measurement of the carbon dioxide-induced glass transition depression in a family of substituted polycarbonates

Direct measurement of the carbon dioxide-induced glass transition depression in a family of substituted polycarbonates

Hydroformylation of 1-hexene using polymer-supported rhodium catalysts in supercritical carbon dioxide

Diffusion and thermodynamic measurements by supercritical fluid chromatography

Contact Info

Product

Resources

About