Fabrication and formation mechanism of closed-loop fibers by electrospinning with a tip collector
Yan Xu1, †, 
, Yu Miao1, †, , Han Wen-Peng1, You Ming-Hao1, Zhang Jun-Cheng1, Dong Rui-Hua1, Zhang Hong-Di1, Long Yun-Ze1, 3, ‡,
, Yu Miao1, †, , Han Wen-Peng1, You Ming-Hao1, Zhang Jun-Cheng1, Dong Rui-Hua1, Zhang Hong-Di1, Long Yun-Ze1, 3, ‡, Optical images of the electrospun Ce(NO3)3/PVA fibers with closed-loop structures obtained at a distance of 10 cm and the applied voltages of (a) 15 kV, (b) 20 kV, (c) 25 kV, and (d) 30 kV. The solution of Ce(NO3)3/PVA contains 1.5 wt.% Ce(NO3)3 and 10 wt.% PVA.
