1. State Key Laboratory of Separation Membranes and Membrane Processes, Department of Chemical EngineeringTianjin Polytechnic University 399 Binshui West Road Tianjin 300387 P.R.China
2. School of Materials Science and EngineeringTianjin Polytechnic University P.R. China
3. Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular EngineeringPeking University Beijing 100871 P.R. China