Effect of Nanoclusters on Dielectric Properties of Epoxy Composites

Serving as the crucial insulation material of high frequency transformers (HFT), the increase of HFT's operating frequency calls for higher performance of epoxy composites. In this study, nanoclusters were introduced into epoxy resin (EP) for the purpose of improving both dielectric properties and breakdown strength. Experimental results show that the introduction of nanoclusters effectively reduces the relative permittivity while significantly enhancing their high-frequency breakdown strength up to <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$113.82 \text{kV} / \text{mm}$</tex>. Compared to conventional nanoparticles doping strategy, nanoclusters improve electrical performance of epoxy composites by forming interfacial region and quantum size effect. This study provides a novel approach to the electrical insulation modification of epoxy composites.