Enhanced direct‐current breakdown strength of Al2O3/epoxy resin composites through plasma fluoridation of fillers interface.

Herein, a method for improving the direct‐current (DC) breakdown strength of the epoxy resin (ER) was proposed. Nano‐Al2O3 was treated with CF4/Ar plasma and doped into the epoxy resin matrix to obtain epoxy composites with high DC breakdown strength in both extremely uneven and slightly uneven electric fields. The reaction essence of plasma fluoridation was characterized, and the dielectric spectrum, volume conductivity, space charge, and carrier trap characteristics of the modified composites were studied. The plasma fluoridation at the fillers‐matrices interface is an effective pretreatment method to enhance insulation, exhibiting good applicability to ceramic/polymer composites. [ABSTRACT FROM AUTHOR]