Fabrication of nanofibres via polyvinylpyrrolidone by sol–gel method and electro-spinning technique

ZrO₂ fibres have been used in aspects of aeronautics and astronautics because of their properties such as high strength, good toughness and thermal shock resistance. In this reported work, polyvinylpyrrolidone (PVP)/Y(NO₃)₃·6H₂O/ZrOCl₂·8H₂O (PVP-precursor) nanofibres were prepared by the sol-gel method and an electro-spinning technique. Then, the ZrO₂ fibres by Y-doping were obtained by calcination of the above precursor fibres at 550°C for 0.5 h. These fibres were characterised by X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, differential scanning calorimetry and thermogravimetry to study the physical and chemical properties. The formation mechanism of ZrO₂ fibres is also illustrated. The results show that: (i) the diameter of the nanofibres is in the range of 500-3000 nm; (ii) PVP-precursor fibres should reach the level of obvious dehydration, oxidation decomposition and phase transition to synthesise ZrO₂ nanofibres; (iii) through thermal poly-condensation reaction, PVP turns into a network structure of graphitised carbon.