Luminescence quenching method for probing the diffusivity of molecular oxygen in highly permeable media

Investigation of Oxygen Permeation through Composites of PMMA and Surface‐Modified ZnO Nanoparticles

“…To determine the t o ; values of the samples pulsed laser experiments were performed and for the product of a and s a value of 1 nm is assumed following the approach of previous authors. [26,27] A recent example, in which this type of approach to measure oxygen permeability in nanocomposites was used, is found in the work of Lu et al [28,29] They investigated among others the effect of surface-modified silica nanoparticles on oxygen diffusion and permeation in poly (dimethylsiloxane) (PDMS). Spectroscopic investigations showed in case of PDMS that in the emission spectra the presence of silica in the film leads to a redshift of the peak position and a broadening of the peak compared to the peak of the neat PDMS film.…”

A Comparative Study of Oxygen Permeabilities of Film‐Forming Polymers by Quenching of Platinum Porphyrin Phosphorescence

“…The obtained Stern-Volmer relationship was combined with the kinetics of diffusion-controlled reactions resulting in an expression to achieve the desired permeability. This approach has found widespread acceptance and we cite the work of Winnik et al [14][15][16][17][18] as an example. In most cases, the permeability coefficient was determined from a Stern-Volmer plot of the lifetimes of the emitters or by measurements of the integral intensity of phosphorescence.…”

“…Method A used in the present work is similar to the method applied in refs. [13][14][15][16][17][18] , however, instead of lifetimes intensities were monitored. The luminescent dye is directly embedded in the polymer film of interest.…”

“…Therefore, the magnitude of a can approach unity for the quenching of triplets. [14,17] For the diameter of encounter complex often the sum of the van der Waals radii of the dye and an oxygen molecule is used. However, the true magnitude of this value can be expected to be smaller because the dye molecule is not a sphere and active collisions are dependent on the direction of the arriving oxygen molecules.…”

“…Among others, Winnik et al used this principle to characterize different poly (alkylaminothiophenylphosphazenes) for their possible application as pressure-sensitive paint. [14,15] Platinum porphyrins were used as dye, but rhenium and iridium complexes were tested, as well. [16] The same group also characterized core-shell soft sphere ionic liquids using this method [17] as well as polymer silica composite films.…”