Production of polyacrylonitrile/boehmite nanofibrous composite tubular structures by opposite-charge electrospinning with enhanced properties from a low-concentration polymer solution

摘要

Polyacrylonitrile (PAN)/boehmite nanofibrous composite tubular structures were fabricated from dilute polymer solutions using an opposite-charge electrospinning method. The samples were characterized by X-ray diffraction, Differential scanning calorimetry, scanning electron microscopy, Fourier-transform infrared spectroscopy, fast Fourier transform, and tensile tests. The presence of boehmite nanoparticles in the electrospun PAN nanofibers prevented bead formation, resulting in uniform fibers with smaller diameters, and improved alignment from low-concentration PAN polymer solutions. 1 wt% boehmite-loaded nanofibrous composite tubular structure was selected as the optimal formulation to proceed with the crystallinity and tensile tests, which showed enhanced crystalline properties as well as an abrupt shift in tensile performance. The tensile properties of the nanofiber strongly depended on their crystalline properties. The strong intermolecular forces (hydrogen bonds) between the Al-OH groups formed at the surface of boehmite nanoparticles and the polar CN groups along the polymer chains. In addition, the high electrical force between the two tips of the needles in the opposite charge set-up can contribute to the control of electrical jet deposition instability when using a low-concentration electrospinning solution, leading to enhanced properties.