a novel method to develop highly conductive functional materials which can effectively shield various electromagnetic effects and harmful radiations . metallized nanotube polymer composites are composed of a lightweight polymer matrix , superstrong nanotubes , and functional nanoparticle inclusions . mnpc is prepared by supercritical fluid infusion of various metal precursors , incorporated simultaneously or sequentially , into a solid nt - polymer composite followed by thermal reduction . the infused metal precursor tends to diffuse toward the nanotube surface preferentially as well as the surfaces of the nt - polymer matrix , and is reduced to form nanometer - scale metal particles or metal coatings . the conductivity of the mnpc increases with the metallization , which provides better shielding capabilities against various emes and radiations by reflecting and absorbing em waves more efficiently . furthermore , the supercritical fluid infusion process aids to improve the toughness of the composite films significantly regardless of the existence of metal .