1. Research Center for Membrane and Film Technology, Kobe University, 1-1 Rokkodaicho, Nada-ku, Kobe 657-8501, Japan
2. Membrane Research and Development Center, Toyobo Company Ltd., 2-1-1 Katata, Otsu, Shiga 520-0292, Japan
3. Desalination Membrane Department, Toyobo Company Ltd., 2-8 Dojima Hama 2-chome, Kita-ku, Osaka 530-8230, Japan
4. Department of Chemical Science and Engineering, Kobe University, 1-1 Rokkodaicho, Nada-ku, Kobe 657-8501, Japan