Monovalent Cation Exchange Membranes with Janus Charged Structure for Ion Separation
Wenguang Wang,
Yanqiu Zhang,
Xiaobin Yang,
Haixiang Sun,
Yadong Wu,
Lu Shao
Affiliations
Wenguang Wang
MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage, State Key Laboratory of Urban Water Resource and Environment, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, China
Yanqiu Zhang
MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage, State Key Laboratory of Urban Water Resource and Environment, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, China; School of Environments, Harbin Institute of Technology, Harbin 150009, China
Xiaobin Yang
MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage, State Key Laboratory of Urban Water Resource and Environment, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, China
Haixiang Sun
School of Materials Science and Engineering, China University of Petroleum (East China), Qingdao 266580, China
Yadong Wu
MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage, State Key Laboratory of Urban Water Resource and Environment, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, China
Lu Shao
MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage, State Key Laboratory of Urban Water Resource and Environment, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, China; Corresponding author.
Monovalent cation exchange membranes (M-CEMs) have been extensively applied in environmental remediation and energy harvesting such as the extraction of Na+ or Li+ from brine and seawater. However, owing to the limitations of membrane structures and materials, M-CEMs have a low perm-selectivity issue. Herein, we proposed a facile approach to construct a novel M-CEM with a Janus-charged structure, consisting of a positively-charged trimesic acid/polyethylenimine surface thin layer and a negatively charged commercial cation exchange membrane (CEM). Selectrodialysis results indicated that the Janus-charged M-CEMs could effectively suppress the migration of anions, which often occurred in porous CEMs, thereby enabling the novel Janus-charged M-CEMs to possess high perm-selectivity and high total cation fluxes. Compared with state-of-the-art M-CEMs, the Janus-charged M-CEM exhibited the highest perm-selectivity of 145.77 for Na+/Mg2+ beyond the contemporary “Upper Bound” plot as well as the excellent perm-selectivity of 14.11 for Li+/Mg2+, indicating its great potentials in ion separation. This study can provide novel insights into the design of Janus-charged M-CEMs for ion separation in diverse environmental and energy applications.
