A strategy for synthesis of copper nanoparticles from recovered metal of waste printed circuit boards

In order to achieve the goals of Circular Economy (CE) for the million tons of Waste Printed Circuit Boards (WPCBs) generated annually, this research aims to move from WPCB recycling to remanufacturing stage and use the recovered high purity Copper (Cu) as a raw material to synthesize Copper Nanoparticles (Cu-NPs) which are a high added value product. Chemical-ultrasonic treatment was used as an eco-friendly approach to separate all layers and components of WPCBs “as received” through dissolution of brominated epoxy resin by solvent Dimethylacetamide followed by liberation and purification of Cu foils to remove any remaining organic materials. Nanoparticle synthesis was performed in three steps: a) preparation of copper (II) acetate from recovered Cu foils by nitric acid and sodium hydroxide, b) preparation of sol-gel of copper (II) acetate solution mixed with poly (vinyl) alcohol, and c) synthesis of Cu-NPs by electrospinning at flow rates 0.2 ml/h and voltage 23-29 kV. SEM, HRTEM, XRD, AAS, and TGA were used to examine the structure of the obtained copper (II) acetate and Cu-NPs. The results showed that the produced Cu-NPs had an average size 5 nm with a synthesis yield 84% (Cu-NPs/mass of recovered copper). Based on the economic assessment, the preparation costs were >4 times lower than commercial prices of similar Cu-NPs.