Fabrication of lightweight conductive material by electroless deposition of copper coating on the surface of poly(ether ether ketone)/multiwalled carbon nanotubes composite

In this study, a reductive film with strong cohesiveness was produced on the poly(ether ether ketone)/multiwalled carbon nanotubes (PEEK/MWCNT) composite with a porous surface by immersing-drying. The reductive film reduced Cu²⁺ ions to Cu⁰ catalysts in situ. With the increase of NaBH₄ concentration in pretreatment process, the Cu⁰ catalysts gradually changed from small spherical particles to large polyhedral particles and the content of Cu⁰ catalysts increased. The small spherical particles covered on the wall of porous network uniformly and the distribution of large polyhedral particles was nonuniform. The Cu⁰ catalysts induced the electroless deposition of copper coating on the composite surface. The deposition rate of copper coating was increased and the sheet resistance of copper coated PEEK/MWCNT was decreased with the increase of NaBH₄ concentration in pretreatment process. The adhesion of the copper coating on PEEK/MWCNT composite reached the highest 5 B scale according to ASTM D3359. Compared with the original PEEK/MWCNT, the electrical resistivity in direction of thickness decreased by six orders of magnitude for copper coated PEEK/MWCNT.