Fabrication of polycrystalline ZnO nanotubes from the electrospinning of Zn²⁺/poly(acrylic acid)

Polycrystalline zinc-oxide nanotubes were fabricated via the polymer-assisted electrospinning technique. Chemically dissolved zinc in a poly(acrylic acid) aqueous solution was formulated to produce electrospun Zn +/polyanion nanofibers. Polyanions were simultaneously employed as zinc ion stabilizers and electrospinning carriers. A calcination process initiated the breakdown of Zn²⁺/vinyl-COO^- species at about 200 °C prior to the main decomposition of the polymer, which occurred at a higher temperature. With increasing calcination temperatures, the growth of ZnO nanograins formed the outer layers of fibers with hollow domains. The ZnO grain sizes were mainly determined, by the calcination temperatures. Furthermore, nanotube diameters and tube thicknesses were successfully manipulated by the electrospinning formula and process. The fabrication of electrospun zinc/poly(acrylic acid) nanofibers and the formation of hollow nanotubes, as a function of calcination temperature, were investigated and discussed.