A new method for preparing hydrophobic nano-copper powders

A novel chemical process for producing hydrophobic nano-copper particles with satisfied anti-oxidation property is described here. The resultant particles have been characterized by X-ray diffraction, size distribution analysis and SEM, TEM observation. Well-dispersed nano-copper particles with c.a. 30 nm in diameter were obtained from the water/organic solution containing 0.2M Cu²⁺ ion, glucose as the first reductant, ascorbic acid as the second reductant. In this process, oleic acid acted as both a phase-transfer agent and a particle protector coordinating their carboxyl end groups on the new generated copper particles surface, the hydrophobic carbon tails of the oleic acids were pointed outwards from the surface of the synthesized particles. This organic film seems to play an important role for prevent the new generated copper particles from oxidation. In addition, this process also adopting two-step reduction method can lead compulsively disconnect nucleation and nucleation growth, and weaken conventional eruptible nucleation. By controlling the first reduction product’s size, this process is more convenient for delaying the nuclei processes and for controlling the ultimate copper particles size.