An electrochemical pretreatment and catalysation process for acrylonitrile-butadiene-styrene utilising silver(II) chemistry

The formation of silver(II) ions in nitric acid was studied using a rotating disc electrode at temperatures of 25°C and a preparative H-type divided cell was used to generate dark brown silver(II) solutions at 50 mA cm^-2, 50°C. When acrylonitrile-butadiene-styrene (ABS) samples were etched in this highly oxidising medium, residual silver(I) species trapped within the polymer cavities were reduced to metallic silver with a reducing agent and, upon exposure to an electroless copper solution, deposition was observed. An FM-01LC Laboratory Electrolyser was used to scale-up the process and peel strengths between the ABS substrate and metallic coating were measured. Adhesion equivalent to a chromic acid pretreatment was achieved. Hence a novel process based upon the aqueous electrochemistry of silver(II) has been developed for etching, catalysing and subsequently metallising ABS.