Space Charge Characteristics of Epoxy Resin/Carbon Quantum Dots Nanocomposites

This work deals with the space charge investigation of nanostructured epoxy resin (Sigma Aldrich DER332) filled with Carbon Quantum Dots. Space charge characteristics of the material are obtained by investigating the characteristic curves coming from Thermally Stimulated Depolarization Current measurement. In particular, the analysis of these curves highlights the occurrence of a significant shift in glass transition temperature in the nanocomposite. Furthermore, the incorporation of Carbon Quantum Dots is confirmed by an increase in the inertia in the first step of the performed measurement and by the presence of a Maxwell-Wagner-Sillars peak in the plot of the discharging current. Nonetheless, activation energies of the relaxation processes appearing in TSDC plots do not experience any detectable variation, thus suggesting that the chemical structure of the nanocomposite retains some characteristics of the neat epoxy resin.