Fluorescence-based self-diagnosis of hyperbranched polyethyleneimine oxidation

Abstract

Polymer oxidation affects the molecular structure and decides the performances, making its rapid and sensitive diagnosis important for evaluating the state of polymer materials and predicting its service life. In this study, fluorometric analysis of the oxidation of hyperbranched polyethyleneimine is realized by Schiff-base reaction. The sensing mechanism is due to the oxidation-mediated generation of oxygen-containing groups, which react with residual primary amine and produce fluorescent Schiff-base compounds. Four hPEIs with different molecular weight possess similar fluorescence variation during oxidation, demonstrating the universality of the proposed technique. Moreover, the successful quality assessment of hPEI verifies the practical application of the proposed fluorescence-based self-diagnosis technique.