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 (10-1300 MHz) 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. (C) 2003 Elsevier B.V. All rights reserved.