1. College of ChemistryNortheast Normal University Changchun 130024 P. R. China
2. College of Chemical EngineeringChangchun University of Technology 2055 Yan’an Street Changchun 130012 P. R. China
3. College of ChemistryJilin University 2699 Qianjin Street Changchun 130012 P. R. China
4. State Key Laboratory of Polymer Physics and ChemistryChangchun Institute of Applied ChemistryChinese Academy of Sciences Changchun 130022 P. R. China