Evolution of copper nanowires through coalescing of copper nanoparticles induced by aliphatic amines and their electrical conductivities in polyester films

[Display omitted] Copper nanowires were synthesized by the wet chemical reduction method using copper sulfate as the copper precursor, aliphatic amines (methylamine, ethanediamine, 1,2-propanediamine) as the inducing reagents, and hydrazine hydrate as the reductant through the aging and reduction processes. The high-resolution transmission electron microscopy (HRTEM) images reveal that the copper nanowires were synthesized by coalescing extremely small-sized copper nanoparticles with the particle sizes of 1–6 nm in copper complex micelles. A longer aging time period favored the coalescing of the copper nanoparticles to form thinner copper nanowires in the following reduction process. The coalescing extent of copper nanoparticles in copper nanowires was highly enhanced by ethanediamine and 1,2-propanediamine as compared with that by methylamine. The copper nanowire-filled polyester films had higher electrical conductivity than the copper nanoparticle-filled ones.