Phase fluorometry as a probe of diffusion-controlled molecular encounters in dense fluids

Journal Article · Sat Dec 15 04:00:00 EST 1979 · J. Chem. Phys.; (United States)

DOI:https://doi.org/10.1063/1.438281· OSTI ID:5763990

Baird, J K; Arakawa, E T; Noid, D W; Petty, H R

The Wilemski--Fixman model for diffusion-controlled molecular encounters in dense fluids is included as one step in a mechanism governing fluorescence quenching. The mechanism is analyzed by mathematics appropriate to a phase fluorometry experiment. As customary, time varying parts of the excitation and fluorescence are found to differ from one another by an amplitude and a phase. Expressions for this amplitude and phase are given in terms of the frequency of modulation of the excitation, the lifetime of the excited state, the diffusion coefficients and radii of the fluorophore and quencher, respectively, and the specific rate of collisions between fluorophore and quencher. There is obtained as a by-product of this analysis an expression for the Stern--Volmer coefficient in terms of the same set of variables. We analyze in some detail a combination of Stern--Volmer and phase fluorometry experiments which can be used to test the Wilemski--Fixman model.

• Research Organization: Health and Safety Research Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830
• OSTI ID: 5763990
• Journal Information: J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 71:12; ISSN JCPSA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360404* -- Materials-- Polymers & Plastics-- Physical Properties-- (-1987)
AZOLES
CARBAZOLES
EMISSION SPECTRA
FILMS
FLUORESCENCE
HETEROCYCLIC COMPOUNDS
LUMINESCENCE
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC POLYMERS
POLYMERS
POLYVINYLS
PRESSURE DEPENDENCE
SPECTRA
VERY HIGH PRESSURE