1. Department of Polymer Science and Engineering, School of Chemical Engineering and Technology; Tianjin University; Tianjin 300350 China
2. Tianjin University-UCGM Joint Research Center for Graphene Application; Tianjin 300350 China
3. Department of Biomedical Engineering; Case Western Reserve University; Cleveland Ohio 44106
4. Unigram Carbon Graphene Material Co., Ltd.; Baoding Hebei 074000 China