1. School of Chemical Engineering, Zhengzhou University, Zhengzhou 450001, China
2. School of Materials Science and Engineering, North China University of Water Resources and Electric Power, Zhengzhou 450045, China
3. Research Center for Membrane and Film Technology, Kobe University, 1-1 Rokkodaicho, Nada, Kobe 657-8501, Japan
4. Laboratory for Membrane Materials and Separation Technologies, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China