Microporous polymer adsorptive membranes with high processing capacity for molecular separation

Zhenggong Wang¹, Xiaofan Luo², Zejun Song², Kuan Lu³, Shouwen Zhu¹, Yanshao Yang², Yatao Zhang ⁴,Wangxi Fang ^2,*（方望熹） & Jian Jin ^1,*（靳健）

¹ Innovation Center for Chemical Science, College of Chemistry, Chemical Engineering and Materials Science & Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou, China

² i-Lab, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences,Suzhou, China  

³ State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Shanxi, China

⁴ School of Chemical Engineering and Energy, Zhengzhou University, Zhengzhou, China

NATURE COMMUNICATIONS , (2022) 13:4169

Trade-off between permeability and nanometer-level selectivity is an inherent shortcoming of membrane-based separation of molecules, while most highly porous materials with high adsorption capacity lack solution processability and stability for achieving adsorption-based molecule separation. We hereby report a hydrophilic amidoxime modified polymer of intrinsic microporosity (AOPIM-1) as a membrane adsorption material to selectively adsorb and separate small organic molecules from water with ultrahigh processing capacity. The membrane adsorption capacity for Rhodamine B reaches 26.114 g m−2, 10–1000 times higher than previously reported adsorptive membranes. Meanwhile, the membrane achieves >99.9% removal of various nano-sized organic molecules with water flux 2 orders of magnitude higher than typical pressure-driven membranes of similar rejections. This work confirms the feasibility of microporous polymers for membrane adsorption with high capacity, and provides the possibility of adsorptive membranes for molecular separation.