1. Research Institute for Soft Matter and Biomimetics; Fujian Provincial Key Laboratory for Soft Functional Materials Research; Department of Physics; Xiamen University; Xiamen 361005 China
2. The State Key Laboratory for Modification of Chemical Fibers and Polymer Materials; College of Materials Science and Engineering; Donghua University; Shanghai 201620 China
3. Department of Physics; Faculty of Science; National University of Singapore; Singapore 117542 Singapore