1. Key Laboratory of Macromolecule Synthesis and Functionalization (Ministry of Education); Engineering Research Center of Membrane and Water Treatment (Ministry of Education), Department of Polymer Science and Engineering, Zhejiang University; Hangzhou 310027 China
2. Center for Membrane and Film Technology; Department of Chemical Science and Engineering, Kobe University, Rokkodaicho 1-1, Nada; Kobe 657-8501 Japan