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, ‡, (a) Optical image of the electrospun Ce(NO3)3/PVA fibers obtained with an applied voltage of 15 kV and under 10 cm distance. The enlarged two parts show (b) a fiber with a curled structure and (c) a closed-loop structure.
