title: Ion-Responsive Channels of Zwitterion-Carbon Nanotube Membrane for Rapid Water Permeation and Ultrahigh Mono-/Multivalent Ion Selectivity.
abstract: The rational combination of polymer matrix and nanostructured building blocks leads to the formation of composite membranes with unexpected capability of selectivity of monovalent electrolytes and water, which affords the feasibility to effeciently remove harmful ions and neutral molecules from the environment of concentrated salines. However, the multivalent ion rejection in salined water of routine nanocomposite membranes was less than 98% when ion strength is high, resulting in a poor ion selectivity far below the acceptable value. In this contribution, the ion-responsive membrane with zwitterion-carbon nanotube (ZCNT) entrances at the surface and nanochannels inside membrane has been proposed to obtain ultrahigh multivalent ion rejection. The mean effective pore diameter of ZCNT membrane was dedicated tuned from 1.24 to 0.54 nm with the rise in Na2SO4 concentration from 0 to 70 mol m(-3) as contrary to the conventional rejection drop in carbon nanotube (CNT) membrane. The ultrahigh selective permeabilities of monovalent anions against divalent anions of 93 and against glucose of 5.5 were obtained on ZCNT membrane, while such selectivities were only 20 and 1.6 for the pristine CNT membrane, respectively. The ZCNT membranes have potential applications in treatment of salined water with general NaCl concentration from 100 to 600 mol m(-3), which are widely applicable in desalination, food, and biological separation processes.
authors.affiliation: †Beijing Key Laboratory of Membrane Materials and Engineering, Department of Chemical Engineering, Tsinghua University, Beijing 100084, PR China.
authors.forename: Tian-Yin
authors.initials: TY
authors.lastname: Liu
authors.affiliation: †Beijing Key Laboratory of Membrane Materials and Engineering, Department of Chemical Engineering, Tsinghua University, Beijing 100084, PR China.
authors.forename: Hao-Ge
authors.initials: HG
authors.lastname: Yuan
authors.affiliation: †Beijing Key Laboratory of Membrane Materials and Engineering, Department of Chemical Engineering, Tsinghua University, Beijing 100084, PR China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Li
authors.affiliation: †Beijing Key Laboratory of Membrane Materials and Engineering, Department of Chemical Engineering, Tsinghua University, Beijing 100084, PR China.
authors.forename: Yuan-Hui
authors.initials: YH
authors.lastname: Tang
authors.affiliation: ‡Beijing Key Laboratory of Green Chemical Reaction Engineering and Technology, Department of Chemical Engineering, Tsinghua University, Beijing 100084, PR China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: ‡Beijing Key Laboratory of Green Chemical Reaction Engineering and Technology, Department of Chemical Engineering, Tsinghua University, Beijing 100084, PR China.
authors.forename: Weizhong
authors.initials: W
authors.lastname: Qian
authors.affiliation: §Department of Chemical Engineering, Process Engineering for Sustainable Systems, KU Leuven, 3000 Leuven, Belgium.
authors.forename: Bart
authors.initials: B
authors.lastname: Van der Bruggen
authors.affiliation: †Beijing Key Laboratory of Membrane Materials and Engineering, Department of Chemical Engineering, Tsinghua University, Beijing 100084, PR China.
authors.forename: Xiaolin
authors.initials: X
authors.lastname: Wang
mesh_terms: D000838:Anions / Q000737:chemistry; D005947:Glucose / Q000737:chemistry; D008567:Membranes, Artificial; D037742:Nanotubes, Carbon / Q000737:chemistry*; D010539:Permeability; D013431:Sulfates / Q000737:chemistry
chemical_list: D000838:Anions; D008567:Membranes, Artificial; D037742:Nanotubes, Carbon; D013431:Sulfates; C012036:sodium sulfate; D005947:Glucose
keywords: carbon nanotubes; ion-responsive; membrane; zwitterion