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 closed-loop fibers obtained at a distance of 10 cm and an applied voltage of 30 kV with concentrations of Ce(NO3)3 of (a) 0 wt.%, (b) 1.0 wt.%, (c) 1.5 wt.%, and (d) 2.0 wt.%.
