Electromagnetic Shielding of Composite Films Based on Graphite, Graphitized Carbon Black and Iron-Oxide

Abstract

The present work regards the development of paint-like composites based on mixtures of carbon materials with magnetite in polyvinyl butyral matrix, and the investigation of the dependence on the electrical characteristics and the frequency of their electromagnetic shielding properties. It was found that high electromagnetic shielding effectiveness requires not only the presence of a high content of carbon components in the composite, but also the absence of an agglomeration of filler particles. Using these paint-like materials, a shielding effectiveness of up to −35 dB of UHF radiation can be obtained. A combination of fillers based on carbon-graphite materials of different morphology and magnetite was found to enhance shielding efficiency.