ElectrospinningPVDF solutions were prepared by dissolving measured amountsof PVDF in different ratios of DMF and acetone and stirring gentlyfor 24 h to form uniform, transparent solutions.Electrospinning was carried out using a 20 ml syringe contain-ing the PVDF solution with a gauge needle. The distance betweenthe gauge needle and ground plate where the paper sample wasplaced was fixed at 15 cm, the feeding rate of solution was set at1.0 ml.h−1, and a DC voltage (between 15 kV–20 kV according tothe concentration of PVDF solution) was supplied to the preparedsolution. After spinning, the paper samples were air-dried in a fumehood.