1. Key Laboratory of New Processing Technology for Nonferrous Metals and Materials, Ministry of Education, College of Materials Science and Engineering; Guilin University of Technology; Guilin 541004 China
2. Key Laboratory of Molecular Engineering of Polymers of Ministry of Education, Department of Macromolecular Science; Fudan University; Shanghai 200433 People's Republic of China
3. Institute of Materials Research and Engineering; A*STAR (Agency for Science, Technology and Research), 3 Research Link; Singapore 117602