ODMR and fluorescence studies of pyrene solubilized in anionic and cationic micelles

Thermal Stability of Nonionic Surfactant Aggregates

“…This probe should be sufficiently hydrophobic to seek out the nonpolar regions of any surfactant assemblies that are formed, thereby giving an indication of the environment within these structures. A prime candidate for such a study is pyrene, which exhibits fluorescence behavior that changes with the polarity of its microenvironment. , Pyrene has been used extensively to determine characteristics of solvent mixtures , and surfactant solutions. , The measured parameter is the I 1 / I 3 ratio, that is, the ratio of the first and third peaks in the fluorescence emission spectrum. It is relatively large in polar environments (e.g., 1.87 in water) and smaller in nonpolar solvents (e.g., 0.58 in cyclohexane) .…”

Interactions of 2,2,2-trifluoroethanol with aqueous micelles of Triton X-100

“…For dynamic quenching we have that F 0 /F = τ 0 /τ [49]. Therefore, from the plot of τ 0 /τ versus [Q], we derive the apparent bimolecular quenching constant k q from a Stern-Volmer type equation: Small values for K D have been also observed for pyrene in aqueous solutions of ionic surfactants in the presence of acrylamide as the quencher [50]. For these systems the quenching constant in the micellar solution is three orders of magnitude smaller than its value in aqueous solution.…”

Effect of Amino Acids on Micellization and Micellar Parameters of Anionic Surfactant Alpha Olefin Sulfonate C14–C16 in Aqueous Solutions: Surface Tension, Conductometric, Volumetric, and Fluorescence Studies

“…In fluorescence studies of aqueous-micellar solutions of C 14–16 AOS both in the absence and presence of AA, pyrene was used as fluorescence probe, and cetylpyridinium bromide was used as fluorescence quencher. This pair of probe–quencher is more suitable for the determination of aggregation number of the ionic surfactants. , The fluorescence spectrum of pyrene (2 × 10 –6 mol·L –1 ) in aqueous solutions of C 14–16 AOS both in the absence and presence of AA was recorded on a Varian Cary Eclips luminescent spectrometer at room temperature, with excitation and emission slits of 10 and 2.5 nm, excitation wavelength of 334 nm, and a rate of scanning of 120 nm·min –1 , respectively.…”

“…This pair of probe− quencher is more suitable for the determination of aggregation number of the ionic surfactants. 21,22 The fluorescence spectrum of pyrene (2 × 10 −6 mol•L −1 ) in aqueous solutions of C 14−16 AOS both in the absence and presence of AA was recorded on a Varian Cary Eclips luminescent spectrometer at room temperature, with excitation and emission slits of 10 and 2.5 nm, excitation wavelength of 334 nm, and a rate of scanning of 120 nm•min −1 , respectively.…”