The relative intensities of excimer and monomer fluorescence of pyrene are shown to be a simple linear function of the viscosity of a homologous series of solvents. This relationship may be represented by η = kC′h, where C′h is the pyrene concentration at which half the fluorescence intensity appears in both the excimer and monomer form. The constant k includes both instrumental and theoretical parameters and is determined empirically. These results have been used to measure the viscosity of the hydrocarbon region of micelles labeled with pyrene. The viscosities of alkyltrimethylammonium bromides with alkyl chain lengths from C10 to C18 were in the range of 125 to 200 cP.
ASJC Scopus subject areas
- Colloid and Surface Chemistry