Spectroscopic and thermodynamic studies of supercritical fluid solutions containing a cosolvent

The addition of a cosolvent to a supercritical fluid (SCF) can alter the properties of the solvent to enhance both solubilities and selectivities for particular solutes through a variety of specific and non-specific interactions. Although many cosolvent effects have traditionally been explained in terms of hydrogen bonding between cosolvents and solutes, we present spectroscopic data that suggest that these interactions may be more subtle. Specifically, fluorescence and absorption spectroscopy have been used to study structure-specific probe molecules (2-naphthol, 5-cyano-2-naphthol, and 7-azaindole) in the supercritical fluids carbon dioxide, ethane, ethylene, and fluoroform, with water, methanol, and ethanol as cosolvents. In liquid solutions, these probes exhibit well characterized spectral responses to an organized, hydrogen bonded solvent environment. The results from SCF solutions indicate significant cosolvent/solute interaction even at 0.3 mole% cosolvent yet there is no evidence for stoichiometric hydrogen bonded complexes.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Chemical Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2011

Author dc:creator

• Tomasko, David Lane

Contributors dc:contributor

• Higdon, Jonathan J.L.

• Chemistry, Physical
• Engineering, Chemical

Statement dc:rights

• Copyright 1992 Tomasko, David Lane

Language dc:language

eng

Identifier

AAI9236609
(UMI)AAI9236609

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/20315