Skip To Main Content

Fluorescence-based Sensor for Oxygen Permeability of Plastic Beverage Containers

Nicholas Dunn, Ryan Wheaton, Lukas Kromer
Ohio Northern University

Polymers used for food and beverage packaging often must have very good gas-barrier properties. Since the permeability of O2 gas through common feedstock materials such as poly(ethylene terephthalate), PET, is affected by typical stretch-blow molding processes for bottle fabrication, we are developing an optical method for determining oxygen transport through intact drink bottles. The sensor material, tris(4,7-diphenyl-1,10-phenanthroline) ruthenium(II) encapsulated in silicone rubber, is applied as a thick film to the inner surface of a transparent bottle and excited using a pulsed laser operating at blue or UV wavelengths. Red fluorescence from the sensor salt is resolved on the microsecond time scale and the fitted decay rate is a function of quenching by oxygen present. Our present limit of detection for O2 is below 1000 ppmv. Fluorescence-based sensors may be applied to rapid testing of permeability through actual containers and will enable measurements of oxygen dissolved within novel micro-layered polymers being developed for advanced packaging applications.

ONU Student Research Colloquium