A new method for the determination of molecular diffusion coefficient in polymer films by simple UV-VIS spectroscopy

Abstract

The possibility to evaluate molecular diffusion coefficient in polymer films directly in-situ is critical to assess barrier properties of packaging systems. Using the polymer packaging itself as smart sensor could lead to increase shelf-life, minimize wastes, and food poisoning effects. In this work we report on a new method that exploit simple UV-Vis spectroscopy to identify diffusion of small molecules in the vapor phase through both commercial polymer packaging systems and into polymer multilayered structures. The new method allows to determine molecular diffusion coefficient values in full agreement with gravimetric data reported in literature.The possibility to evaluate molecular diffusion coefficient in polymer films directly in-situ is critical to assess barrier properties of packaging systems. Using the polymer packaging itself as smart sensor could lead to increase shelf-life, minimize wastes, and food poisoning effects. In this work we report on a new method that exploit simple UV-Vis spectroscopy to identify diffusion of small molecules in the vapor phase through both commercial polymer packaging systems and into polymer multilayered structures. The new method allows to determine molecular diffusion coefficient values in full agreement with gravimetric data reported in literature.