Nanoparticulate copper – routes towards oxidative stability

Abstract

A modified polyol-based reduction method in ethylene glycol that incorporates poly(N-vinylpyrrolidone) (PVP, M_av = 10 000; 40 000; 55 000) as polymeric anti-agglomerant alongside a reducing additive (N₂H₄·H₂O, NaBH₄, NaH₂PO₂·H₂O) has been employed to investigate the influence of synthetic parameters on the purity, morphology and stability of an array of polymer-coated copper nanoparticles. While data point to ethylene glycol being capable of acting as a reductant in this system, the use of NaH₂PO₂·H₂O as co-reductant in tandem with the presence of PVP (M_av 40 000) has rendered nanoparticles with a mean size distribution of 9.6 ± 1.0 nm that exhibit stability towards oxidation for several months. These data allow us to probe fundamentally how oxidatively stable nano-copper might be achieved.