Steady-state fluorescence of polystyrene plasticized by supercritical carbon dioxide

Journal Article · Sat Jun 01 04:00:00 EDT 1996 · Applied Spectroscopy

DOI:https://doi.org/10.1366/0003702963905736· OSTI ID:633974

Li, M; Bright, F V ^[1]

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1. Department of Chemistry, Natural Sciences and Mathematics Complex, State University of New York at Buffalo, Buffalo, New York 14260-3000 (United States)

A steady-state fluorescence study of low-molecular-weight polystyrene (MW=1,060thinspg/mol and 13,000 g/mol) plasticized in supercritical CO2 is reported. In addition to excitation wavelength, molecular weight, and polystyrene concentration dependencies, CO2 density also strongly affects the emission spectral contours. A major increase in the steady-state fluorescence intensity and a significant decrease in the polystyrene 320 to 365 nm fluorescence intensity ratio are observed when CO2 density is increased. Concentration and conformational changes in the polystyrene molecules are used to explain the observations, and these results are proposed to arise from changes in the plasticization power of supercritical CO2 over the density range studied. A theoretical model is proposed that is based on the assumption that, at low CO2 densities and low polymer concentrations, polystyrene intermolecular interactions are negligible. The proposed model is able to fit our observed fluorescence data from a CO2 reduced density of 0.3 to 1.4. {copyright} {ital 1996} {ital Society for Applied Spectroscopy}

• DOE Contract Number: FG02-90ER14143
• OSTI ID: 633974
• Journal Information: Applied Spectroscopy, Journal Name: Applied Spectroscopy Journal Issue: 6 Vol. 50; ISSN 0003-7028; ISSN APSPA4
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
CARBON DIOXIDE
COMPARATIVE EVALUATIONS
CONFORMATIONAL CHANGES
FLUORESCENCE
MATHEMATICAL MODELS
PLASTICIZERS
POLYSTYRENE
STEADY-STATE CONDITIONS
SUPERCRITICAL STATE