Electromagnetic shielding of epoxy resin composites containing carbon fibers coated with polyaniline base

The electromagnetic shielding properties of epoxy resin composites containing short carbon fibers coated with a layer of non-conducting polyaniline base have been studied. Below the percolation threshold the composites show a high AC conductivity at high frequencies (10–1300MHz) and low DC conductivity at the same time. They can thus be used as a protective material transmitting high-frequency signals and shielding low-frequency ones which do not short circuit the surface of electronic systems.