## Files in this item

FilesDescriptionFormat

application/pdf

9010810.pdf (8MB)
(no description provided)PDF

## Description

 Title: Intermolecular interactions in supercritical fluid solutions from fluorescence spectroscopy Author(s): Brennecke, Joan F. Doctoral Committee Chair(s): Eckert, Charles A. Department / Program: Engineering, Chemical Discipline: Engineering, Chemical Degree Granting Institution: University of Illinois at Urbana-Champaign Degree: Ph.D. Genre: Dissertation Subject(s): Engineering, Chemical Abstract: Much of the unusual behavior in supercritical fluids (SCF's), including enhanced solubilities, synergistic effects of mixed solutes, and entrainer effects, may be explained by a region around the solute that has a higher density than the bulk. We present a new technique to investigae SCF's using fluorescence spectroscopy to probe the local interactions. In contrast to thermodynamic measurements, this technique determines the strength of interactions on a molecular scale, which is important in the development of more accurate thermodynamic models. For pyrene, naphthalene, dibenzofuran and carbazole in SCF CO$\sb2$, C$\sb2$H$\sb4$ and CF$\sb3$H, the results indicate stronger solute/solvent interactions near the critical point and local densities that are liquid-like, even when the bulk density is quite low. We also present excimer fluorescence data that emphasize the importance of solute/solute interactions in dilute supercritical fluid solutions. Finally, results from exciplex fluorescence studies of a solute/SCF/entrainer system indicate a dramatic solvent effect on the photophysical kinetics. Issue Date: 1989 Type: Text Language: English URI: http://hdl.handle.net/2142/23786 Rights Information: Copyright 1989 Brennecke, Joan F. Date Available in IDEALS: 2011-05-07 Identifier in Online Catalog: AAI9010810 OCLC Identifier: (UMI)AAI9010810
﻿