The use of Electron Paramagnetic Resonance (EPR) in the probing of the nanodielectric interface

EPR (sometimes annotated as ESR) has been carried out on functionalized nanoscale silica embedded in crosslinked polyethylene (XLPE) in comparison with the base resin. In situ EPR measurements under an applied electric field have been carried out, and the technique is outlined. The preliminary measurements show that EPR can detect trap sites in the bulk and interfacial polymer. In addition, EPR can detect texture in the polymer due to its processing. At the same time, measurements to determine the dynamics and spatial distribution of the space charge have been carried out under similar conditions using the pulsed electro-acoustic analysis technique. The results are discussed in terms of the way in which the nanoparticles affect the local polymer environment.