The size distribution (hydrodynamic diameter) of Copper nanoparticles was evaluated by Dynamic Light Scattering (DLS).Experiments were carried out using Zetasizer Nano Series (MalvernInstruments). Each value was obtained as average from three runs with at least 10 measurements. The size of the nanoparticlesand their concentration were also measured by NTA using NS500(NanoSight). All measurements were performed at 25◦C.