Photocured Organofunctional Silicon-Based Polymer and Its Y2O3 Nanocomposite as the Luminescence Tracer of Thermal History

Abstract

Materials with irreversibly changing properties after thermal heating are of great interest as thermal history trackers and are in demand as part of almost any device. Here, a promising thermoreporting material based on an organosilicone nanocomposite is suggested. Samples of photocured poly(1-trimethoxysilylpropyloxymethyl)ethylenoxide (polyGPTMS) and its nanocomposite with a filler of Y2O3 nanoparticles (polyGPTMS–Y2O3) were obtained with UV laser polymerization. The subsequent heat treatment of the samples revealed luminescence, the spectral position of which demonstrated a red shift with temperature increase. Comparative analysis of luminescence and Fourier-transform infrared spectroscopy spectra as well as theoretical modeling were used to characterize the structural peculiarities of the polymer and the nanocomposite. It was found that the luminescence behavior correlates with the color centers formation in the course of thermal treatment. The red shift of luminescence with temperature is associated with the redistribution of the chemical network and changes in the contribution of different color centers. The main effect is connected with an E′ center and oxygen-deficient centers, where the predominant contribution of the latter at high temperatures determines the observed luminescence red shift. The different dynamics of the color centers formation for polyGPTMS and polyGPTMS–Y2O3 results in a correspondingly stepwise and gradual luminescence red shift. The uncovered gradual luminescence red shift with thermal treatment of the polyGPTMS–Y2O3 makes the nanocomposite a promising tracer of thermal history. Using polyGPTMS–Y2O3 nanocomposite as a reporting material allows establishing not only the fact of heating but also the heating temperature.