1. Department of Materials Science and Engineering City University of Hong Kong Hong Kong 999077 P. R. China
2. Department of Mechanical Engineering and Biomedical Engineering Carnegie Mellon University Pittsburgh Pennsylvania 15213 USA
3. Department of Chemistry The Chinese University of Hong Kong Hong Kong 999077 China
4. Department of Civil Engineering The University of Hong Kong Hong Kong S.A.R. 999077 China
5. Institut Européen des Membranes, IEM UMR 5635, Université Montpellier, ENSCM, CNRS Montpellier 34095 France
6. Beijing Key Laboratory of Membrane Materials and Engineering Department of Chemical Engineering Tsinghua University Beijing 100084 P. R. China
7. Shenzhen Research Institute City University of Hong Kong Shenzhen 518057 China