Preparation and conductive property of Cu coatings and Cu-graphene composite coatings on ABS substrate

A facile, low-cost and environmentally-friendly technique has been developed to prepare highly conductive copper-graphene nanosheet (Cu-GNS) composite coatings on ABS (Acrylonitrile-Butadiene-Styrene) substrate. The surface activation of ABS substrate was obtained by a chrome-free and palladium-free pretreatment consisting of molecular bonding. Before electroplating Cu, the homogeneous single Ag film on ABS surface was achieved by the electroless spray-plating process. In addition, the deposition of Cu and GNS increased in the coatings along with the current density increasing. Four-point-probe test confirmed that the resistivity of Cu coatings (0.08 mΩ mm) and Cu-GNS composite coatings (0.05 mΩ mm) was in the same order of magnitude as pure copper (0.0175 mΩ mm) at high current density. Meanwhile, comparing with the Cu coatings, the resistivity of Cu-GNS composite coatings was reduced by nearly 40% at the same current density. The conductive property was significantly improved owing to the deposition of GNS. Therefore, this work was expected to expand the method of polymer materials surface metallization.