首页|Highly efficient Li~+/Mg~(2+)separation of monovalent cation permselective membrane enhanced by 2D metal organic framework nanosheets

Highly efficient Li~+/Mg~(2+)separation of monovalent cation permselective membrane enhanced by 2D metal organic framework nanosheets

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Monovalent cation permselective membranes(MCPMs)manifest remarkable effectiveness and potential in lithium extraction whereas facing the challenge to achieve high permselectivity and high Li~+ permeability simultaneously.In this work,Zn-TCPP,a kind of two-dimensional nanosheet with abundant negative charges,was successfully synthesized via surfactant-assisted method and introduced into surface cross-linked SPES membrane to fabricate MCPMs.The physicochemical properties,electrochemical properties and Li~+/Mg~(2+)separation performance of resulted MCPMs were systematically estimated.As ions passing through the membrane,dense PVA/GA crosslinked layer separated Li~+ and Mg~(2+)by pore-size sieving effect.Afterwards,uniformly distributed Zn-TCPP nanosheets with rich negative charges and physically adsorbed water molecules elevated the charge density and water content in the membrane and thus expedited Li~+ transporting.Therefore,high Li~+/Mg~(2+)permselectivity(P_(Mg~(2+)~(Li~+))= 8.99)and Li~+ permeation flux(J_(Li~+)= 9.12 × 10~(-9)mol cm~(-1)·s~(-1))were obtained.Furthermore,membrane surface resistance was reduced from 108.99 Ω.cm~2 to 24.12 Ω·cm~2.This study points out the feasibility of the new method for accelerating monovalent ion transport and alleviating the restriction between ion permeation and permselectivity in selective ion exchange membranes.

ElectrodialysisMonovalent cation permselective membraneSurface crosslinking modificationZn-TCPP nanosheetsLi~+ permeability

Lu Tao、Xiaojuan Wang、Fadong Wu

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Key Laboratory of Marine Chemistry Theory and Technology,Ministry of Education/Frontiers Science Center for Deep Ocean Multispheres and Earth System/College of Chemistry and Chemical Engineering,Ocean University of China,Ojngdao 266100,China

Rebon Membrane Separation Technology(Jiangsu)Co.Ltd,Hangzhou Branch,Hangzhou 310051,China

2022

Separation and Purification Technology

Separation and Purification Technology

EISCI
ISSN:1383-5866
年,卷(期):2022.296
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