Pressure effects on the fluorescence decay of micellar solutions

Journal Article · Thu Mar 26 04:00:00 EST 1987 · J. Phys. Chem.; (United States)

DOI:https://doi.org/10.1021/j100291a028· OSTI ID:6800049

Turro, N J; Okamoto, M; Kuo, P L

The monomer fluorescence decay of pyrene was measured in sodium dodecyl sulfate (SDS) and hexadecyltrimethylammonium chloride (HDTCl) micellar solutions as a function of pressure from 0.1 to 203 MPa at 25 /sup 0/C by a single-photon-counting technique. The decay curves were analyzed successfully by a conventional fluorescence decay analysis for micellar solution over the pressure ranges examined. From the analysis, it was found that the rate constant (k/sub E/) for intramicellar excimer formation decreased significantly with increasing pressure in both micellar solutions, while the cmc and the aggregation number (N) for SDS and HDTCl micelles were found to be almost independent of pressure. The activation volumes for excimer formation were 19 and 16 cm/sup 3//mol for SDS and HDTCl micellar solutions, respectively. An attempt to obtain an activation volume for a nonionic detergent was unsuccessful because of the failure of the decay profile to fit the theoretical model. However, activation volumes for microviscosity were obtained by studying the pressure dependence of intramolecular excimer formation of a dinaphthylpropane probe. The diffusion process in micelles and microviscosities are discussed by comparing the activation volume for excimer formation with those for microviscosities determined by the pressure effect on intrmolecular excimer formation, and by comparing the results with those reported in the literature for a dipyrenylpropane probe.

• Research Organization: Columbia Univ., New York, NY
• OSTI ID: 6800049
• Journal Information: J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 91:7; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400500* -- Photochemistry
AROMATICS
CHEMICAL REACTION KINETICS
CONDENSED AROMATICS
DATA
EMISSION SPECTRA
EXPERIMENTAL DATA
FLUORESCENCE
HYDROCARBONS
INFORMATION
KINETICS
LUMINESCENCE
MEDIUM TEMPERATURE
MICELLAR SYSTEMS
NUMERICAL DATA
ORGANIC COMPOUNDS
PRESSURE DEPENDENCE
PYRENE
REACTION KINETICS
SPECTRA