Effect of solvent on interface of TiO2-PVP/PAN flexible nanofibers

Abstract

Flexible TiO2-PVP/PAN photocatalyst in form of core/sheath nanofibers were fabricated from combining sol-gel method and coaxial electrospinning technique. Polyacrylonitrile (PAN) was selected as core polymer, while polyvinylpyrrolidone (PVP) was selected as polymer for sheath solution to occur sol-gel process of titania. There are two solvents that commonly used in sol-gel process of titania, which are DMF and ethanol. PAN has limited solubility, therefore, the effect of solvent that occur at core/sheath interface is greatly affected properties of the final products. This research would mainly focus on investigating the effect of solvent at core/sheath interface in flexible nanofibers. The various conditions such as polymer concentration (PVP), titania-precusor (TTIP) amount, aging time of titania-precusor solution and electrical potential used in electrospinning process were investigated their effects. The resultant fibers were characterized by Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy with energy-dispersive x-ray (SEM-EDX), Transmission electron microscope (TEM), and X-ray diffraction (XRD). The result shows that there is no core/sheath interface when using DMF as solvent in sheath solution and the components from sheath section diffused into core section. After changing the solvent to ethanol, ethanol interact with PAN at core/sheath interface and this prevent fusion of sheath section into core section.