Effect of collector grounding on directionality of electrospun titania fibers

TiO2 nanofibers were prepared by using electrospun TiO2/polyvinylpyrrolidone fibers by drying for 5 h in air and subsequent annealing for 3 h at 500 °C. Uniform and smooth fibers with diameters of 120 ± 10 nm were observed at a PVP concentration of 0.09 g/ml, a Ti(OCH(CH3)2)4 concentration of 0.14 g/ml, a flow rate of 0.5 ml/h, and an electric field of 1 kV/cm, respectively. TiO2/PVP nanofibers were also electrospun by varying the collector grounding design to improve the axial alignment of fibers. The collector is composed of two pieces of conductive substrates separated by a gap of 1.5 mm. In addition, the collector consisting of two sets of substrates placed by 90° are prepared for a grid structure of the fibers. Both collectors show that the charged nanofibers are stretched to span across the gap between the electrodes.