DESALINATION
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2018
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IF 6.603
Ping Xu,Wei Wang,Xiaoming Qian,Haibo Wang,Changsheng Guo,Nan Li,Zhiwei Xu,Kunyue Teng,Zhen Wang
To effectively separate Mg 2+ and Li + from salt lake brine with high Mg 2+ /Li + mass ratio, a positive charged nanofiltration membrane with abundant -NH 3 + and -NH 2 + was designed and fabricated via interfacial polymerization between polyethyleneimine (PEI) and trimesoyl chloride (TMC) on the polyethersulfone ultrafiltration membrane. Zeta potential test revealed that at pH below 9.3, the resulting membrane exhibited a high positive charge due to a large amount of unreacted amine groups on the PEI branch. In the separation process, Donnan exclusion effect dominated the separation performance of resulting membranes for Mg 2+ and Li + . The results showed that the Mg 2+ /Li + mass ratio declined from initial 20 to 1.3 and the separation factor S Mg , Li was as low as 0.05 with a pure water permeation of 5.02 L/(m 2 hbar) after filtration with resulting NF membrane. The difference between the rejection for Mg 2+ and Li + reached up to 76%. Compared with membrane in previous studies, the separation performance for Mg 2+ and Li + of positive charged NF membrane prepared in this work increased more than one time. This research demonstrated the potential of positive charged PEI-TMC composite NF membrane for the separation of Mg 2+ and Li + from salt lake brine with high Mg 2+ /Li + mass ratio.
研究领域:
材料科学
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环境科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
WATER RESEARCH
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2025
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IF 12.4
Huijun Yu,Xieyang Xu,Yingsong Liu,Chenshuo Wang,Linxuan Gao,Jianbing Wang
Nanofiltration (NF) offers an energy-efficient approach for lithium recovery from brines. Conventional NF membranes rely on the positively charged polyamide layer formed via interfacial polymerization (IP) of polyethyleneimine (PEI) and trimesoyl chloride (TMC) to repel Mg 2+ more strongly than Li + , but their Mg 2+ /Li + selectivity remains constrained by limited control over pore size distribution. Here, we develop polyamide (PA) layers using amphiphilic dioctyl sulfosuccinate sodium (DOSS)-mediated electrospray interfacial polymerization (DEIP). Electrospray-assisted polymerization at the interfaces of abundant immiscible microdroplets produces thinner PA layers with reduced transport resistance and accelerates monomer diffusion in a non-selective manner. Molecular dynamics (MD) simulation and density function theory (DFT) calculations further reveal that DOSS selectively regulates the diffusion behavior of PEI and TMC within microdroplets, enabling the formation of PA layers with uniform pore structures and a positively charged surface. These structural advantages deliver precise ion sieving for lithium extraction, achieving a Mg 2+ /Li + selectivity of 142 and water permeance of 13.45 L·m −2 ·h −1 ·bar −1 . The DEIP membrane also demonstrates stable Mg 2+ /Li + separation over seven days of continuous NF operation. This work underscores the promise of DEIP membranes for high-efficiency lithium extraction and highlighted their potential for practical brine-based lithium recovery.
研究领域:
材料科学
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膜技术
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分离科学
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环境工程
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锂提取
✓ 已验证
产品关联
DOI
PubMed
高影响因子
DESALINATION
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2025
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IF 9.8
Shuwei Jia,Jun Wei,Xinyu Ma,Zhi Wang
High-efficiency lithium extraction from salt lakes is pivotal to meet escalating lithium demand driven by energy storage and electric vehicle industries. In this study, the small-molecule aminoacetonitrile (AAN) was introduced as an aqueous-phase co -monomer to modulate the interfacial polymerization process between polyethyleneimine (PEI) and trimesoyl chloride (TMC). Specifically, the primary amine in AAN molecules reacted with acyl chloride moieties in TMC, occupying reaction sites and thereby preserving a larger fraction of unreacted primary amine groups on the PEI chains within the separation layer, which significantly enhanced the membrane's surface positive charge. Simultaneously, the nitrile groups of AAN preferentially coordinated with Li + ions to effectively counteract the repulsive effect of the strongly positively charged membrane surface on Li + . This “charge-coordination” synergistic mechanism enabled precise control over the separation process. When treating mixed salt solution with a Mg 2+ /Li + mass ratio of 100, the optimized membrane achieved a separation factor of 74.7, along with enhanced MgCl 2 rejection of 99.3 % compared to virgin membrane's 93.9 %, and reduced LiCl rejection from 56.3 % to 49.3 %. Notably, upon treatment of simulated salt lake brine, the membrane manifested a pronounced Li + enrichment effect, with a LiCl rejection rate of −8.8 % while retaining a high MgCl 2 rejection capacity. This study employed a simple preparation process with industrialization potential, providing a guiding strategy for constructing high-selectivity membranes for Mg 2+ /Li + separation.
研究领域:
材料科学
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膜科学与技术
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分离工程
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能源材料
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无机非金属材料
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Polymer Materials
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2026
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IF 5.2
Ying Cheng,Yanxia Sun,Shengde Dong,Luxiang Ma,Xin He,Qi Xu,Ziyu Wang,Yu Tang,Ping Li,Chunxi Hai,Yuan Zhou
The nanofiltration (NF) membrane, as an emerging lithium resource extraction technology, precisely screens Mg2+ and Li+ through the Donnan effect and steric hindrance. However, most NF membranes still struggle to break through the “trade-off effect”, and how to effectively overcome this effect to achieve a balance between high ion rejection and high permeability remains a great challenge. In this study, sodium alginate (SA) was added to the aqueous phase during the preparation of polyethylenimine-trimesoyl chloride (PEI-TMC) NF membranes. The bifunctional groups of SA can achieve synergistic effects: −COOH can produce electrostatic interaction with PEI to reduce amine sites, while −OH can form a competitive relationship with PEI to reduce the reactivity of amine groups, thereby forming a loose and thin separation layer. The permeability was significantly improved, and its water flux increased from 34.68 L·m–2·h–1 to 92.04 L·m–2·h–1, representing a nearly 3-fold increase compared to the PEI-TMC NF membrane. At the same time, the reduction of amine groups participating in the reaction under the optimal conditions increases the positive charge on the membrane surface, maintaining the original high separation performance SLi+/Mg2+=21.18). Through a three-stage nanofiltration process, the Li+/Mg2+ ratio in real salt-lake brine can be reduced to 0.86, and the improved adsorption-membrane coupled process can further reduce the Li+/Mg2+ ratio to 0.04, significantly reducing the interference of high-concentration Mg2+ in the lithium extraction process. Finally, this study systematically compared the cost and environmental impact of the modifier used in this work with those of other common modifiers. The results show that the proposed modifier is cost-effective and environmentally friendly, with higher feasibility for practical industrial applications. Therefore, this work exhibits promising application prospects in the field of lithium extraction from salt lakes.
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产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
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2024
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IF 8.4
Zhiguo Li,Fangbo Zhao,Hongxu Chen,Liu Yang,Jiaming Zhang
The active layer of the thin film composite (TFC) nanofiltration membrane prepared by traditional interfacial polymerization (IP) was usually a non-homogeneous state with dense in the middle and loose on both sides. Such structure would reduce the stability of membrane in operation. In this paper, a novel electrospray polymerization nanofiltration (EPNF) membrane was fabricated for efficient and long-term stable separation for Mg 2+ /Li + by multiple scan 3D electrospray printing technique. The active layer consisted of two homogeneous separation layers, the piperazine-trimesoyl chloride (PIP-TMC) inner layer and polyethyleneimine based (PEI-TMC) outer layer. With a fixed scan of inner layer, the effect of scan number of PEI-TMC outer layer on the performance of EPNF membrane was analyzed detailly from chemical structure and ion separation performance. Under the synergistic effect of electrostatic repulsion and pore size screening, the EPNF membrane achieved a Mg 2+ /Li + separation factor of 36.28 and only 1.5 % performance loss in the operation of 150 h. The electrospray polymerization process presented unique advantages in preparing TFC nanofiltration membranes with long-term separation stability.
研究领域:
材料科学
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环境工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
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2023
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IF 9.5
Huanhuan Wu,Haoyue Zhao,Yakai Lin,Xin Liu,Lin Wang,Hong Yao,Yuanhui Tang,Lixin Yu,Haihui Wang,Xiaolin Wang
Positively charged nanofiltration membrane has gained significant interest in magnesium and lithium separation due to its separation mechanism, especially in salt lake-based lithium industry. To obtain a high-density positive charged surface and high Li + /Mg 2+ selectivity, a novel thin-film nanocomposite (TFN) nanofiltration (NF) membrane for recovery of Li + from Mg/Li mixtures with Mg 2+ /Li + ratios of 20 was successfully prepared by using polymeric amine polyethyleneimine (PEI) and monomeric amine silane coupling agent (3-diamino-methyl-cyclohexyl triethoxysilane, DTES). Then the effect of DTES on the surface properties and performance of the prepared DTES/PEI/TMC TFN membranes were investigated. Chemical composition analysis revealed that DTES not only hydrolyzed to Si–OH and then self-polymerized to Si–O–Si, but also reacted with the self-carrying acyl chloride of 1,3,5-benzene trichloromethane (TMC). Moreover, SiO 2 nanoparticles were in-situ generated from DTES inside the PA layer with high compatibility. Due to the compatible properties with the positively charged PEI polymer, the reacted DTES was distributed uniformly in the formed TFN selective layer with no noticeable aggregation. The doping of SiO 2 into the polyamide network gave rise to the enlargement of the membrane pore size, enhanced the surface hydrophilicity, and reinforced the surface positive charges. The water flux of the DTES/PEI/TMC membrane improved from 36.9 L m −2 h −1 to 49.58 L m −2 h −1 compared to the PEI/TMC membrane. Additionally, the Mg 2+ and Li + rejection of the optimized membranes was 91.46% and −10.5%, respectively, with permeability and selectivity (S Li, Mg = 12.95) superior to that of the commercial NF membranes. Considering the commercial availability of DTES, this study not only offers a high-performance nanofiltration membrane for recovering lithium from brines but also provides a feasible strategy for industrial separation of other monovalent and divalent ions.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
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2021
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IF 3.498
Xiaoqing Xie,Yanfei Wang,Weini Zhou,Can Chen,Zeng Xiong
A new synthetic method was designed to prepare poly (trimesoyl chloride-co-polyethyleneimine) (PEI-TMC). Characterization of PEI-TMC was investigated by FTIR, SEM, EDS , XPS, TGA , and BET. TGA test revealed that the PEI-TMC had excellent thermal stability. The BET specific surface area (4.74 m 2 g −1 ) and pore diameter of about 9.44 nm indicated that PEI-TMC possessed a mesoporous structure. The adsorption behavior of U(VI) on the PEI-TMC was investigated. The thermodynamic analysis showed that the process of PEI-TMC adsorption of U(VI) was endothermic and spontaneous, and the adsorption efficiency was better at higher temperatures. The U(VI) sorption on PEI-TMC was conformed to the Langmuir adsorption isotherm and pseudo-second-order kinetic models . The adsorption mechanism of U(VI) with PEI-TMC was systematically elucidated by XPS and FTIR. Under the best condition, the maximum adsorption capacity of PEI-TMC could reach 212.8 mg g −1 by calculating the Langmuir isothermal model. It indicated that PEI-TMC was a potential adsorbent for the treatment of U(VI)-containing wastewater.
研究领域:
环境科学
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材料科学
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化学工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）