1. Institute of Printing and Packaging Engineering Xi'an University of Technology, Xi'an, Shaanxi 710048, P.R. China,
2. Department of Polymer Engineering, Materials Engineering Institute Soochow University, Suzhou, Jiangsu 215021, P.R. China
3. Department of Applied Chemistry, School of Science Northwestern Polytechnical University, Xi'an, Shaanxi 710072, P.R. China