DESALINATION
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2024
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IF 8.3
Junhua Li,Zhipeng Xu,Junbin Liao,Edison Huixiang Ang,Xuanhua Chen,Junjie Mu,Jiangnan Shen
Ion selective separations play crucial roles in the fields of energy storage, pollution management, and industrial processes, etc. Ion exchange membranes (IEMs) offer promise for these separations but often lacking the required selectivity . In this work, we have developed a kind of IEM based on metal-organic frameworks (MOFs) to enhance membrane separation performance for electrodialysis (ED). Specifically, for poly(arylene ether sulfone)-based anion exchange membranes (AEMs), we introduced the modified MOFs through doping to create a transport pathway for target ions, leveraging their precise size-based separation effects. This approach significantly improves ion selectivity. Remarkably, at a current density of 2.5 mA·cm −2 , the monovalent ion selectivity (Cl − /SO 4 2− ) of PAES-UIO-66-Pyr could reach 54.26, while the monovalent ion selectivity (NO 3 − /SO 4 2− ) could reach 55.90. These enhancements may stem from the incorporation of MOF particles, which facilitate the formation of fixed-size channel structures within membrane matrix. These fixed-size channels, coupled with the hydrophobic differences between the original poly(arylene ether sulfone) polymer, created a composite channel system that significantly improved the separation performance for monovalent ions, including Cl − /SO 4 2− and NO 3 − /SO 4 2− .
研究领域:
材料科学
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环境工程
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化学工程
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DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
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2014
·Vol. 132
·期 8
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IF 1.64
Huining Deng,Zixia Wang,Wei Zhang,Baisong Hu,Shaofeng Zhang
This study reports the modification of commercial cation-exchange membrane by layer-by-layer adsorption of polyethyleneimine and poly(acrylic acid) (PAA) to endow them with monovalent ion selectivity. The chemical and morphological changes of the modified membrane surface were examined by ATR-FTIR and SEM, respectively. The permselectivity for monovalent cations of the membranes was investigated by electrodialysis experiments. The effects of deposited bilayer number, the salt concentration, and pH of the dipping polyelectrolyte solutions on selectivity were investigated. Meanwhile, the resistance of membranes was measured taking energy consumption into consideration. The polyelectrolyte multilayer was crosslinked using epichlorohydrin to improve stability, and the durability of the composite membrane was studied. Separation mechanism of the composite membrane was also investigated. It is demonstrated that the bivalent cations are mainly rejected by electrostatic repulsion from the positive charge on the surface of the composite membranes. The sieving effect of the dense structure of skin layer becomes more pronounced with the number of deposited layers increased. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132 , 41488.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2022
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IF 16.744
Jiadi Ying,Yuqing Lin,Yiren Zhang,Yan Jin,Hideto Matsuyama,Jianguo Yu
The development of cation exchange membranes (CEMs) with high monovalent/divalent cation selectivity has great potential for enhanced salt separation for wastewater reclamation, and layer-by-layer (LbL) self-assembly of polyelectrolyte films with high monovalent selectivities among cations has expanded the applications of such membranes. However, the structure–property relationship for constructing multilayered polyelectrolyte films with enhanced separation performance remains poorly understood. This study reports a novel CEM engineered by coating a [polyethyleneimine/polystyrene sulfonate (PEI/PSS)] n alternate electro-deposition multilayer on a polyacrylate substrate membrane. The newly developed CEM exhibited a monovalent selectivity of 4.59 for Li + /Mg 2+ with an optimal permeation of 0.16 mmol·cm −2 ·h −1 for Li + , demonstrating a competitive separation property compared to state-of-the-art permselective membranes. A detailed quantitative investigation provides the underlying insights into the monovalent selectivity for each polyelectrolyte layer. The results indicate negligible interface impedance toward monovalent cations but strengthened repulsion against divalent cations, thereby promoting a quick passage for monovalent cations while imposing temporal retardation on divalent cations during the electrodialysis (ED) process. Therefore, this study elucidates the characteristic reason for the enhanced monovalent ion permselectivity of LbL polyelectrolyte membranes in electro-driven separation processes.
研究领域:
材料科学
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化学工程
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环境工程
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DOI
高影响因子
ACS ES&T Water
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2022
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IF 0
Chengyi Wang,Long-Fei Ren,Diwen Ying,Jinping Jia,Jiahui Shao
Capacitive deionization (CDI) is highly attractive for seawater desalination, while the trade-off between total salt adsorption capacity (SAC) and monovalent ion selectivity is a big challenge for current electrodes, especially facing solution containing organics. Herein, a simple approach was used to prepare a novel dual-layer membrane coating electrode (D-MCE) by depositing ion exchange polymers onto activated carbon fiber (ACF) to overcome this issue. Performances of the ACF, single-layer MCE, anion exchange membrane ACF, and D-MCE were investigated. Compared to ACF, the single-layer MCE showed an increased total SAC from 435.7 to 593.0 μmol/g with a reduced Cl–/SO42– selectivity from 0.9 to 0.4. The introduction of the membrane increased total SAC to 524.3 μmol/g and decreased Cl–/SO42– selectivity to 0.7. The D-MCE exhibited an improved total SAC to 679.5 μmol/g by inhibiting the co-ion repulsion and Faradaic reaction. Meanwhile, the D-MCE enabled fast Cl– diffusion and presented a high selectivity (3.8). After 50 cycles, the D-MCE exhibited an almost unchanged total SAC and selectivity even in the presence of organics. The narrowed pores and negative outermost layer endowed the D-MCE with an outstanding anti-fouling behavior, which well explained its stable performance. These findings confirmed the high potential of the D-MCE in addressing the trade-off and provided valuable insights into the design of the CDI electrode for desalination.
研究领域:
环境科学
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材料科学
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化学工程
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水处理
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产品关联
DOI
危险品化学品经营许可证（带存储）