Journal of Environmental Chemical Engineering
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2024
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IF 7.4
Yufei Yan,Jin Wang,Wubin Wang,Chao Han,Kaili Huo,Qingyun Zhang,Ning Wang
Positively charged nanofiltration (NF) membranes are widely used to separate Li + and Mg 2+ , which play an important role in extracting lithium from salt lakes. Despite its widespread use, the polyethyleneimine-trimesoyl chloride (PEI-TMC) membrane has attracted attention due to its limited permeance and separation efficiency. To address these challenges, we introduced amine-functionalized titanium dioxide (TiO 2 -NH 2 ) nanoparticles into the interfacial polymerization (IP) reaction. The introduction of TiO 2 -NH 2 reduced the diffusion rate of PEI and formed nanoscale water channels in the polyamide (PA) layer. This modification effectively modulated the structure of the NF membrane. The NF membrane exhibited high water permeance (9.65 L·m −2 ·h −1 ·bar −1 ) and Li + /Mg 2+ selectivity ( S Li, Mg = 16.31) when 0.03 wt% TiO 2 -NH 2 was used. The DLVO theory and transition state theory showed that the introduction of TiO 2 -NH 2 improved the rejection of Li + and Mg 2+ by the membrane. Furthermore, the optimized NF membranes demonstrated excellent stability during long-term filtration and in the mixed salt solutions with varying Mg 2+ /Li + mass ratios. This work is of great significance for designing and advancing membrane materials that facilitate the efficient separation of lithium from salt lakes with high Mg 2+ /Li + mass ratios.
研究领域:
材料科学
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环境工程
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高影响因子
ACS Applied Materials & Interfaces
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2024
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IF 8.3
Jia-Shuai Chen,Jing Wang,Ji-Hong Zhang,Zhi-Yuan Guo,Pan-Pan Zhang,Xiao-Fu Guo,Jie Liu,Zhi-Yong Ji
Achieving separation of lithium and magnesium with similar radii is crucial for the current lithium extraction technology from salt lakes, which usually possess a high lithium-to-magnesium ratio. Herein, we proposed the facile sequential interfacial polymerization (SIP) approach to construct electronanofiltration membranes (ENFMs) with a bilayer charged structure consisting of a high positively charged surface and a negatively charged sublayer. The trimesoyl chloride (TMC) concentration was adjusted to enhance the −COOH content and negative charge of the polyamide sublayer to promote Li+ migration, and then the quaternized polyethylenimine was introduced to the membrane surface by the SIP process to increase the positive charge density on the surface of the ENFMs, which would block the migration of Mg2+ and enhance the Li+/Mg2+ selectivity of the ENFMs. The optimal quaternary-modified ENFMs achieved outstanding selectivity for Li+/Mg2+ (49.85) and high Li+ flux (4.10 × 10–8 mol cm–2 s–1) at a current density of 10 mA cm–2. Moreover, in simulated brines with low lithium concentration and high Mg2+/Li+ ratio, the optimal ENFMs also displayed elevated Li+/Mg2+ selectivity (>45), highlighting the substantial promise of the membranes for practical applications.
研究领域:
材料科学
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化学工程
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环境科学
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PubMed
高影响因子
JOURNAL OF MEMBRANE SCIENCE
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2024
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IF 8.4
Zhiyuan Zha,Tingyu Li,Ismail Hussein,Ying Wang,Song Zhao
The scarcity of lithium can be effectively addressed by extracting it from salt-lake brines. In this work, aza-crown ether (diazo-18-crown-6, DA18C6) was coupled into a polyamide (PA) network interfacial polymerized by trimesoyl chloride and polyethyleneimine (PEI) for efficient Li + /Mg 2+ separation. The embedment of DA18C6 molecule into PA network was confirmed by structural characterization and density functional theory simulation, which enhanced crosslinking degree and reduced average pore size of PA selective layer. In addition, the strong interaction between DA18C6 and Li + was proven through molecular dynamics simulation. The resulting PEI@DA18C6-PA membrane displayed a high pure water permeance of 10.4 L⋅m − 2 ⋅h − 1 ⋅bar − 1 and an excellent Li + /Mg 2+ separation factor ( S Li,Mg ) of 11.2, which was comparable with most reported Li + /Mg 2+ separation membranes . Furthermore, the PEI@DA18C6-PA membrane was employed in a three-stage NF treatment process to filtrate simulated brines containing a high Mg 2+ /Li + ratio of 57. The results demonstrated that Li + can be effectively concentrated and extracted through the membrane to obtain a permeate with an ultralow Mg 2+ /Li + ratio of only 0.03, suggesting that PEI@DA18C6-PA membrane has great application potential in lithium extraction from salt-lake brines.
研究领域:
材料科学
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环境工程
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高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2024
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IF 8.1
Jian Lu,Chenye Dai,Shilong Li,Dong Zou,Yuqing Sun,Wenheng Jing
Similar physicochemical properties render the separation of Li + /Mg 2+ from salt lake brine difficult for two-dimensional (2D) membranes. Herein, ultraefficient Li + /Mg 2+ separation was achieved under the influence of an electric field using MXene/carbon nanotube (CNT) membranes developed on tubular ceramic substrates via thermal crosslinking. Crosslinking reactions between CNTs and MXene yielded well–intercalated CNTs between MXene nanosheets, forming antiswelling MXene/CNT membranes (MCMs) (interlayer spacing: 8.04 Å) suitable for Li + /Mg 2+ separation. At 2.8 V applied voltage, the MCMs exhibited Li + flux of 0.0491 mol m −2 h −1 and high Li + /Mg 2+ selectivity of 54.5, which outperform existing state–of–the–art 2D membranes. Specifically, under a positive electric field, Li + with a small hydration diameter and low hydration energy permeated through the membrane nanochannels more easily than Mg 2+ , increasing and decreasing Li + and Mg 2+ flux, respectively. Additionally, Mg 2+ retention was enhanced via the complexation of enriched Mg 2+ with –OH and –COOH on the membrane surface. The MXene membrane surface was thus reconfigured to be positively charged, inducing effective Mg 2+ rejection. This study offers a novel and practical approach for efficiently separating Li + /Mg 2+ as well as monovalent/multivalent ions.
研究领域:
材料科学
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化学工程
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高影响因子
JOURNAL OF MEMBRANE SCIENCE
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2025
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IF 9
Yufei Yan,Jin Wang,Wubin Wang,Chao Han
Positively charged polyethyleneimine (PEI) nanofiltration (NF) membranes exhibit great potential for Li + /Mg 2+ separation. However, the dense nature of the polyamide (PA) layer presents a challenge in breaking through the permeance bottleneck, significantly hindering its further application. In this study, 1-(2-aminoethyl)piperazine (AEP) was first incorporated into the PEI solution as a structural regulator to adjust the microstructure of the PA separation layer. The structure of the PA selective layer was fine-tuned with the incorporation of AEP, enlarging the spacing between the long-chain molecules of PEI, and established hydrogen bonding interactions with PEI. This led to the generation of Turing structures on the membrane surface, which enhanced permeance. Meanwhile, the primary amine groups in AEP were protonated in water, aiding in boosting positive membrane charge and subsequently elevating its rejection capability for divalent cations. The ingenious combination of large molecule PEI and small molecule AEP served a dual purpose in promoting the membrane construction and performance. The optimized PEI/AEP-TMC NF membrane exhibited high pure water permeance (11.24 L m −2 h −1 bar −1 ) and excellent Li + /Mg 2+ selectivity ( S Li, Mg = 24.59), while also achieving higher Li purity and Li recovery. Insights into the remarkable performance of the modified membranes were gained through the transition state theory. Additionally, the internal stress generated in the NF process was determined by utilizing the principles of thin plate theory, revealing that the NF membrane possesses good pressure resistance and maintains stable operation at pressures up to 9 bar. This study demonstrates the capability of PEI/AEP-TMC NF membranes for Li + /Mg 2+ separation and offers a novel aqueous phase monomer for the preparation of NF membranes specifically for Li + /Mg 2+ separation.
研究领域:
材料科学
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化学工程
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环境科学
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高影响因子
Nano-Micro Letters
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2026
·Vol. 18
·期 1
·126
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IF 36.3
Zhang Zixuan,Kong Yan,Li Runlai,Yue Xiaolin,Deng Hao,Zheng Yu,Zhang Sui,Zhang Runnan,Jiang Zhongyi
Covalent organic framework (COF) scaffold membranes with gate-lane nanostructure were prepared.
The gating layer affords high rejection to Mg 2+ and thus high Li + /Mg 2+ selectivity. The permeating layer bearing Li + lanes and Cl − lanes facilitates Li + transport and thus high Li + permeability.
The COF scaffold membrane exhibits the true selectivity of 231.9 with Li + enrichment of 120.2% at the Mg 2+ /Li + mass ratio of 50, exceeding the ideal selectivity of 80.5.
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PubMed
高影响因子
JOURNAL OF MEMBRANE SCIENCE
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2019
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IF 7.015
Chengyi Zhang,Yingxin Mu,Wen Zhang,Song Zhao,Yuxin Wang
Developing effective technologies for extraction of Li + from salt-lake brines with high Mg 2+ /Li + ratios is paramount for sustainable utilization of lithium resources in electric vehicle and nuclear energy industries. In this work, hybrid membranes were prepared with polyvinyl chloride matrix and six metal−organic frameworks (MOFs@PVC) to separate Li + from Mg 2+ in solution. The effects of pore size sieving and sulfonation of the MOFs on the Li + /Mg 2+ separation efficiency were evaluated using the current-voltage ( I – V ) method, and the stability of the MOFs@PVC membranes was systematically evaluated. The loading amount of MOFs and the thickness of the membranes were also optimized for Li + transport and selectivity. The results show that the small pore size and sulfonation of MOFs are benefit to separate Li + from Mg 2+ . Specifically, PVC-based hybrid membrane containing HSO 3 -UiO-66 shows the highest selectivity for Li + (Li + /Mg 2+ > 4), with the diffusion coefficient of 2.0×10 -10 cm 2 s -1 for Li + and 4.67×10 -11 cm 2 s -1 for Mg 2+ . This study highlights the stable sulfonated Zr-based MOF with suitable pore sizes for membrane-based Li + /Mg 2+ separation, and provides a potential alternative for recovering lithium from salt-lake brines.
研究领域:
材料科学
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化学工程
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环境科学
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高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2023
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IF 8.6
Xiaolei Cui,Guodong Kong,Shengchao Wei,Yuchen Cui,Pengyao Yu,Zixi Kang,Hailing Guo
Advanced ion transportation channels aided by charge and suitable aperture play a crucial role in achieving precise separation of ions. Here, we report a MOF composite membrane with electropositive surface and sub-nanometer-sized ion transport channels for efficient Li + /Mg 2+ separation. The membranes were fabricated using MOF “porous monomers” and trimesoyl chloride (TMC) through interfacial polymerization, and subsequently modified with amino-functionalized polyethyleneimine (PEI). The abundant porosity of the MOFs composite membrane includes the inner and the intergranular pores of MOF provided a rapid transport channel for Li + ions, and a superior Li + permeation rate of 0.68 mol m −2 h −1 (a 10 times enhancement compared to the currently leading MOF membranes). Moreover, the improved positively charged surface (from −78 mV to + 4 mV at pH = 7) and reduced mean pore diameter (from 1.13 nm to 0.8 nm) of the membrane caused a remarkable selectivity of 13.2 for Li + /Mg 2+ . The design concept of the above MOFs based membrane provides a novel approach for developing high-quality MOF composite membranes for improving Li + /Mg 2+ separation performance.
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材料科学
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化学工程
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高影响因子
JOURNAL OF MEMBRANE SCIENCE
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2026
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IF 9
Jia-Chen Zhang,Bing-Xin Gu,Hui-Qian Huo,Yue Shen,Ming-Jie Yin,Quan-Fu An
Construction of positively charged nanofiltration membranes is essential for extracting lithium ions from salt-lake brine to meet the growing demand of the new energy industry. However, conventional membranes suffer from low water permeability due to the large thickness of the fabricated positive-charged polyamide (PA) layer, which increases transport resistance. To address this challenge, a porous interlayer was introduced to regulate the formation of the PA layer and accelerate water transport. Specifically, water-dispersible conjugated microporous polymer (CMP) fibers were synthesized and blended with positively charged polyethyleneimine (PEI) to form a porous, positively charged interlayer. The PEI in this interlayer further participated in the interfacial polymerization process, tailoring the PA morphology and converting the originally negative surface charge to positive. As a result, a dual positively charged membrane was obtained, featuring an enlarged surface area in the PA top layer and a porous structure in the interlayer. Benefiting from the synergistic effects of the Donnan exclusion and reduced transport resistance, the membrane exhibited outstanding separation performance in purifying lithium from a Mg 2+ /Li + mixed solution (mass ratio 20), achieving a water permeance of 11.3 L m −2 h −1 ⋅bar −1 and a separation factor of 43.8. Furthermore, the membrane maintained stable performance during a 10-day continuous operation, demonstrating strong promise for practical applications.
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高影响因子
Journal of Water Process Engineering
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2026
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IF 6.6
Zhigang Ning,Mengling Fang,Baitong Zhang,Muhammad Junaid,Jiao Tang,Qinggang Huang,Xuanlin Li,Xin Huang,Haizhou Xue,Jinglai Duan,Jie Liu,Huijun Yao
A synergistic membrane–solution strategy combining enlarged sub-nanoporous PI membrane with EDTA complexation achieves high Li + flux (73 mmol h -1 m -2 ) and exceptional Li + /Mg 2+ selectivity (351). • The EDTA-induced size and charge transformation of Mg 2+ enables effective electrostatic and steric rejection by negatively charged sub-nanopores, breaking the permeability–selectivity trade-off. • The system demonstrates robust separation performance (selectivity > 284) even at Mg 2+ /Li + ratio up to 60, with EDTA 4- being efficiently regenerated and reused over multiple cycles. Efficient extraction of lithium-ion from salt-lake brine remains a significant challenge, primarily due to the similar physicochemical properties of Li + and Mg 2+ , and the inherent trade-off between permeability and selectivity in conventional membrane processes. Herein, we propose a synergistic membrane–solution strategy that integrates an enlarged sub-nanoporous polyimide membrane (ESN-PI) with ethylenediaminetetraacetate (EDTA 4- ) complexation to enhance the Li + flux and Li + /Mg 2+ selectivity simultaneously. The ESN-PI membrane, fabricated via heavy-ion irradiation and controlled alkaline etching, provides enlarged transport channels that significantly improve Li + permeation. Meanwhile, EDTA 4- selectively chelates Mg 2+ to form a bulky, negatively charged [EDTA-Mg] 2- complex, which is electrostatically repelled and sterically hindered by the negatively charged sub-nanopores, thereby greatly suppressing Mg 2+ transmembrane transport. The coupled system delivers a high Li + flux of up to 73 mmol h -1 m -2 and an exceptional Li + /Mg 2+ selectivity of 351. Notably, the separation performance remains robust (selectivity > 300) even at a high feed Mg 2+ /Li + ratio of 60, and EDTA 4- can be efficiently regenerated and reused over multiple cycles. This research utilized heavy ion irradiation technology to prepare a more economical cation exchange membrane. By coupling the membrane with the EDTA complexation strategy, it was able to resolve the contradiction between permeability and selectivity in the ion separation process based on the membrane, providing a promising strategy for extracting lithium from brines with high magnesium ion content. Polymer membranes are widely used for the extraction of lithium resources from salt-lake. The enlarged sub-nanoporous polyimide membranes (ESN-PI) combined with EDTA 4- to achieve efficient Li + /Mg 2+ separation. EDTA 4- can combine with Mg 2+ to form a bulky, negatively charged [EDTA-Mg] 2- complex. The lithium flux and Li + /Mg 2+ selectivity reaches 0.073 mol·h -1 ·m -2 and 351, respectively. This work demonstrates a viable and economically feasible route to decouple the permeability–selectivity trade-off in membrane-based ion separation, offering a promising strategy for lithium extraction from high-Mg 2+ brines. Download: Download high-res image (86KB) Download: Download full-size image
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高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2026
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IF 8.8
Daojiang Zhu,Shuhong Zhao,Chen Yang,Zheng Liu,Yifan Li,Chang Huang,Yuan Xia,Tingting Xu,Xingya Li,Tongwen Xu
Mixed-matrix membranes (MMMs) incorporating covalent organic frameworks (COFs) offer a promising strategy to overcome the permeability-selectivity trade-off effect in conventional polymer membranes for ion separation. However, agglomeration of COF fillers often leads to structural defects and performance degradation in MMMs. Herein, we report in situ synthesized CA@COF MMMs by integrating fibrous COF (TpPaCOOH) with cellulose acetate (CA) at a low loading of 1.63 wt%, achieving hydrogen bond-enhanced interfacial compatibility and uniform filler dispersion. In the binary-ion system for Li + /Mg 2+ separation, despite this minimal COF content, the resulting CA@TpPaCOOH membrane exhibits 21-fold and 16-fold enhancements in Li + /Mg 2+ selectivity compared with pristine CA and COF membranes, respectively, reaching a selectivity of ∼51 and a Li + flux of ∼0.3 mol m -2 h -1 . Moreover, the CA@TpPaCOOH membranes demonstrate a scalability with consistent performance across batch-to-batch synthesis and retention of >83.2% selectivity in pilot-scale (900 cm 2 ) preparations. This highly reproducible, low-dosage strategy provides a transformative pathway for efficient lithium recovery from brine.
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DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2024
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IF 8.4
Chi Jiang,Shibo Bai,Jiawang Li,Ming Wang,Yan Zhou,Yingfei Hou
ABSTRACT Extraction of lithium resources from salt lake brines is an effective method to solve the shortage of lithium resources nowadays. However, magnesium-lithium separation has become a critical issue for lithium extraction from salt lakes with high Mg 2+ /Li + ratio, due to the similar ionic characteristics of Li + (0.38 nm), and Mg 2+ (0.43 nm). Herein, a amine monomer containing crown ether group (4'-aminobenzo-15-crown-5-ether (NH 2 -B15C5)) was introduced into the interfacial polymerization (IP) process of piperazine (PIP) and homotrimethylene tricarbonyl chloride (TMC) to prepare polyamide (PA) nanofiltration (NF) membranes with Li + selective transport channels. NH 2 -B15C5 shows good compatibility and selective complexation to Li + , which acts as Li + selective transport channels effectively retaining Mg 2+ and allowing Li + to cross the membrane smoothly, therefore solving the problem of poor lithium-magnesium separation performance of most of the NF membranes currently. Molecular dynamics simulations (MD) also confirmed that NH 2 -B15C5 has a stronger affinity for Li + than for Mg 2+ . The NH 2 -B15C5/PIP-TMC membrane exhibited excellent separation performance and water permeance in simulated salt lake brine (2000 ppm, W Mg/Li =100), where the S Li, Mg and water permeance were 32.2 and 8.22 L·m -2 ·h -1 ·bar -1 . Importantly, the crown ether is introduced into the PA separator layer in the form of covalent bonds, hence showing excellent stability. Overall, an NF membrane with high lithium-magnesium separation performance was designed for the extraction of lithium resources from high Mg 2+ /Li + ratio salt lake brine.
研究领域:
材料科学
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化学工程
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环境科学
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高影响因子
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