Nano- and micro-filler combination enabling practical use of nanocomposite insulating materials

Recent interests concerning nanocomposites are shifting emphasis from fundamental research to application-oriented research. In this study, nano- and micro-filler mixed composites were made and evaluated toward practical use of nanocomposite insulating materials. Some kinds of the nano-filler/micro-filler combinations such as nano-layered silicate/micro-silica, nano-silica/micro-silica and nano-titania/micro-silica were compared from viewpoints of volume resistivitiy, relative permittivity, thermal expansion and insulation breakdown properties. Comprehensive consideration based on experimental results determined a candidate nano- and micro-filler mixed composites to make trial models. An aluminum conductor and a vacuum interrupter were molded from the nano- and micro-filler mixed composites for the first time in nanocomposite research.