Fabrication of metallized electrospun copper nanofiber webs

The conductive metallic nanofibers were prepared by using a combined technology of electrospinning and metallization. The electrospun polyurethane and poly(vinyl alcohol) (PVA) nanofibers are metallized with different thicknesses of metal (Cu, Ni) layer via a metallization. The thickness of the metallic layer, which is ranging from 50 nm to 200 nm, was controlled. The resultant metallized nanofibers are characterized using field emission scanning electron microscopy (FE-SEM), wide angle X-ray diffraction (WAXD), and thermogravimetric analysis (TGA). FE-SEM micrographs demonstrate that the nano-scaled metallic layers are well deposited onto the nanofibers. TGA result indicates that thermal stability of the metallized nanofibers was enhanced due to the barrier effects of the metallic thin layer. WAXD data also confirm that the metallic layers are well deposited onto the nanofibers. Remarkably, the fibrous morphologies were satisfactorily conserved after removal of the nanofiber template by heat treatment at ca. 400 °C for 24 hr., suggesting the successful deposition of metal layer onto the nanofiber template, and thereby resulted in the formation of metallic nanofibers and nanotubes depending on the diameter of electrospun nanofibers and the thickness of the deposited metallic layers in the conductive metallic nanofibers. In addition, it was observed that the metallized nanofibers exhibit higher conductive properties depending on the thickness of the deposited metallic layers.