Congjie Gao1, Nanping Xu2, Weihong Xing3. 1. Center for Membrane and Water Science & Technology, Zhejiang University of Technology, Hangzhou, 310014 China. 2. State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, 211816 China. 3. National Engineering Research Center for Special Separation Membranes, Nanjing Tech University, Nanjing, 211816 China.