JOURNAL OF MEMBRANE SCIENCE
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2021
·
IF 8.742
Dan Lu,Tao Ma,Saisai Lin,Zhijun Zhou,Ge Li,Quanfu An,Zhikan Yao,Qi Sun,Zhilin Sun,Lin Zhang
The separation of Li + and Mg 2+ is a decisive step for achieving high-grade lithium extraction from salt-lake brines to circumvent the lithium supply shortage and sustainability. However, polymer nanofiltration membranes suffer from low lithium selectivity and are hindered by complicated preparation and miniaturized scales. Here, we report a facile surface charge-inversion strategy via a unique secondary non-aqueous medium interfacial reaction of polyethyleneimine to construct a selective positive-nanolayer on nanofiltration membranes surface for selective separation of lithium ions from concentrated magnesium/lithium mixtures. The introduction of amine moieties not only increases the Donnan potential but also improves the compactness of the membrane, which simultaneously enhances the Donnan exclusion and size sieving for the Mg 2+ ion with higher valence and larger hydration ion size. The surface interaction theory (DLVO) verified that the high positive-charge density provided an excellent selectivity to allow passage of Li + but reject Mg 2+ , and the separation factor ( S Li/Mg ) achieved 12.37 at a high Mg 2+ /Li + mass ratio of 150. Such highly positive transmembrane potential barrier simultaneously endowed the membrane surface with the anti-fouling performance against Ca 2+ . We anticipate that our facile and scalable surface charge-inversion will greatly advance lithium ions permselectivity membranes design and application in lithium extraction.
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 Materials Chemistry A
·
2025
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IF 9.5
Ning Zhang,Yuan Li,Wei Zhang,Yanling Liu,Yongjian Pei,Jie Zhao,Ping Ning,Kai Li
The effective and sustainable separation and recovery of monovalent and divalent metal ions from spent lithium-ion batteries after acid/alkali leaching still remains a big challenge to hydrometallurgical technologies. In this work, we prepared a novel crown ether-ionic liquid functionalized membrane for the selective separation of mono/divalent ions using electrodialysis (ED). a novel membrane was designed by incorporating 15-crown ether-5 (15C5), a crown ether with specific recognition for alkali metal ions, through combining interfacial polymerization and self-assembly techniques into the tunable ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C4mim][NTf2]). The resultant hybrid coating forms a channel structure for the selective transport of monovalent ions. Systematic characterisations on membrane structure, physicochemical properties, and electrochemical performance were performed before and after modification. The ion transport mechanism was performed using ion diffusion mathematical modeling and density functional theory. The designed crown ether ionic liquid functionalized modified membrane 15C5-IL(2)/Cu-MPD showed excellent selectivity for various monovalent/divalent ion pairs of Li+/Mg2+, Na+/Mg2+, and K+/Mg2+ with the values of 5.33, 5.45, and 13.39, respectively. Besides, the membrane was pH-responsive, and it showed a selectivity of Li⁺/Mg²⁺ at 10.45 in the case of pH 7.5. This may be due to the synergistic effect of pore size screening brought about by the distribution of modified components and specific interactions, for instance 15C5/O--Li+. This simple approach opens a new avenue in the quest for selective IEMs for separations of certain cations by ED.
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
SEPARATION AND PURIFICATION TECHNOLOGY
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2024
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IF 8.1
Tong Wen,Yunliang Zhao,Bowen Kuang,Yupeng Sun,Ying Li,Huatao Wang,Licai Chen,Renbo Gao,Lingjie Zhang,Tingting Zhang
The novel two-dimensional (2D) channel membranes have great potential for effective Li + /Mg 2+ separation due to the rapid ion transport and precise adjustment of their channels. However, the solution composition greatly affects the control of channel height, resulting in an unsatisfactory selectivity performance. Herein, the 2D montmorillonite membranes are used to understand the causes of channel instability and explore the effective solutions. It is found that the changes in solution component can enlarge the channel height by changing the cross-linking constraint of Fe 3+ between MMT nanosheets, thus leading to a weak sieving effect. To improve the channel constraint and its Li + /Mg 2+ separation, the end face and interfacial layer constraint of nanosheets are proposed. As an effective strategy to strengthen the constraint effect, glutathione can modify the end faces of nanosheets and enhance the mutual binding force between them through its oxidative transformation. Besides, the construction of an interfacial layer can also limit channel swelling by altering the membrane hydration and wetting. These strategies will also form a synergistic regulatory effect. Consequently, a superior membrane is obtained and presents an improved selectivity of 8.89 at 100:1 Mg 2+ /Li + ratio. These innovative approaches offer a valuable framework for creating high-performance 2D channel membranes, which can also support their wider application in the Li + /Mg 2+ separation.
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
Energy Technology
·
2019
·Vol. 7
·期 9
·1900454
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IF 3.163
Xue Li,Yujie Zhang,Jingwei Shen,Shun-an Cao,Ting Li,Fei Xu
Rechargeable Mg batteries are attractive candidates for large-scale energy storage batteries with high safety due to the low-cost and non-dendritic metallic Mg anode. However, exploring high-performance cathode materials is blocking their development. Herein, a high-rate rechargeable Mg battery is established with a AgCl cathode, delivering a high reversible capacity of 70.3 mAh g −1 at 100 mA g −1 , an outstanding rate capability of 32.6 mAh g −1 at 1000 mA g −1 , and a superior long-term cyclability over 500 cycles. Further investigation of the mechanism demonstrates that a conversion reaction takes place between AgCl and metallic Ag 0 for the cathode. The solid-state Mg 2+ diffusion coefficient is as high as 8.1 × 10 −11 cm 2 s −1 , which would be the reason for the high rate capability. The current study reveals significant insights to select promising Mg-storage conversion cathodes by a combination of soft anions and soft transition-metal cations.
研究领域:
材料科学
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电化学
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DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2024
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IF 8.1
Binbin He,Ying Fu,Yun Zu,Yunxiang Nie,Yi Mei
Fluorine (F) is a high-value resource that has been overlooked in the production of wet-process phosphoric acid (WPA) due to its high susceptibility to complexation with metal cationic impurities, hindering F efficient recovery and subsequent phosphoric acid purification. In this paper, a co-precipitation strategy is proposed for recovering F from the WPA. Varieties of combinations between metal cation (Na + , Mg 2+ and Al 3+ ) and F - with different molar ratios in aqueous and phosphoric acid systems are designed to explore the co-precipitated regulation. Results show that the simultaneously removal efficiencies of Al 3+ , Mg 2+ and F - can be higher than 90 % in the form of NaAlMgF 6 and Na 3 AlF 6 precipitations as the n(Na + ): n(Al 3+ ): n(Mg 2+ ): n(F - ) = 5: 1.5: 1: 6 in pure systems. DFT calculations further confirm that the NaMgAlF 6 precipitation is the most stable structure identified by using XRD Rietveld refinement. Based on this fact, extra Na + and F - are added into the industrial WPA, so that the Na + , Al 3+ , Mg 2+ and F - are co-precipitated in the form of NaAlMgF 6 , and the ultimate removal efficiencies can exceed 90 % under the optimal conditions. Besides, low-cost cycling recovery of Na + and F - are also investigated. These findings are promising for the efficient utilization of F resources from phosphate rock and other ores, which is of great economic and environmental significance.
研究领域:
化学工程
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环境科学
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DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
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2024
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IF 8.4
Wubin Wang,Jin Wang,Yufei Yan,Kaili Huo,Chao Han,Qingyun Zhang
The positively charged nanofiltration (NF) membrane prepared via interfacial polymerization (IP) of polyethyleneimine (PEI) and trimesoyl chloride (TMC) has drawn considerable attention for lithium-magnesium separation, particularly crucial for lithium recovery from salt lakes with high Mg 2+ /Li + mass ratios. However, NF membranes prepared solely from amine monomers have not achieved efficient Li + and Mg 2+ separation. In this study, PEI-g-C 3 N 5 /TMC composite NF membranes were successfully fabricated by mixing amino-rich graphitic carbon nitride (g-C 3 N 5 ) with PEI, followed by the IP reaction of the mixed solution with TMC. Molecular dynamics (MD) simulation results showed that g-C 3 N 5 had an attractive effect on PEI, which led to a decrease in the diffusion rate of PEI, thereby resulting in a thinner separation layer. Density functional theory (DFT) revealed that g-C 3 N 5 competed with PEI, leading to a reduction in the crosslinking within the polyamide (PA) layer and subsequently causing an increase in the surface pore size of the membrane. Besides, the hydrophilicity and positive charge of the modified membrane were both improved. MD simulations, transition state theory, and DLVO principles indicated that the modification of the PA layer by g-C 3 N 5 enhanced the repulsion of Mg 2+ and the transport of Li + during the NF process. This breakthrough effectively overcame the trade-off effect between membrane separation and permeability, especially at a g-C 3 N 5 content of 0.06 wt%, where the lithium-magnesium selectivity coefficient ( S Li, Mg = 18.18) and pure water flux (Flux = 58.59 L m −2 h −1 ) reached the optimum values. Meanwhile, the PEI-g-C 3 N 5 /TMC membrane demonstrated stable separation performance during prolonged filtration and in solutions with varying Mg 2+ /Li + mass ratios. This study not only provides an effective strategy for the design of NF membranes but also expands the application prospects of nanomaterials in the field of membrane separation.
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
Membranes
·
2026
·Vol. 16
·期 8
·270
·
IF 4.2
Yu-Tong Yin,Rui Jia,Zhen-Liang Xu,Sen Wang,Rui Han
Extracting lithium from salt-lake brines boasts distinct advantages including low production cost, low energy consumption and low environmental risks, and will serve as a primary supply source of lithium salts in the future. This trend raises higher demands for the efficiency and cost-effectiveness of lithium extraction technologies. Nanofiltration (NF) membranes, renowned for their superior discrimination between monovalent and divalent ions, have been extensively utilized to obtain Li + from Mg 2+ -rich saline brines. In this study, positively charged NF membranes aimed at Li + /Mg 2+ fractionation were fabricated via surfactant-interlayer-assisted interfacial polymerization (SIAIP). Catechol (CA) and polyethyleneimine (PEI) were utilized to construct the CA/PEI interlayer, and oil-phase dodecyl phosphate (DDP) was used as an additive for interfacial polymerization (IP). The strongly bonded CA/PEI nanoaggregates improved interlayer stability and preserved the positive charge of the double-layer membrane. DDP adsorbed piperazine (PIP) at the two-phase interface through electrostatic interactions, accelerating PIP diffusion and forming a thick polyamide (PA) layer with uniform pores. The combination of CA/PEI interlayer and DDP synergistically enhanced size-sieving and Donnan effects. With MgCl 2 and LiCl rejections of 97.9% and 36.2% respectively, the optimized membrane shows superior selectivity for Li + over Mg 2+ . Moreover, the membrane exhibited weak electrostatic screening and concentration polarization, showing excellent operational stability under varied Mg 2+ -Li + ratios and feed concentrations.
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DOI
PubMed
高影响因子
JOURNAL OF MEMBRANE SCIENCE
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2026
·
IF 8.8
Zhiguo Li,Fangbo Zhao,Chengbao Geng,Hongxu Chen,Liu Yang,Wennan Liu
The efficient separation of lithium (Li + ) and magnesium (Mg 2+ ) from salt-lake brines remains a critical challenge due to their similar hydrated radii. Herein, we report a novel dual-charged Janus nanofiltration (NF) membrane fabricated via 3D electrospray printing for precise Li + /Mg 2+ separation. The membrane features a negatively charged bottom layer and a positively charged top layer. Crucially, an amphiphilic ionic liquid ([Bmim][BF 4 ]) was introduced into the polyethyleneimine (PEI) aqueous phase of the top layer as a modulator. This ionic liquid enhanced PEI diffusion across the liquid-liquid interface, significantly increasing the density of residual amino groups. Consequently, the optimized membrane (EP-P 30 ) exhibited a highly positive surface charge (22.63 mV at pH 7), increased hydrophilicity, and a narrow pore size distribution. These structural and chemical optimizations translated to exceptional separation performance. The EP-P 30 membrane achieved a high pure water permeance of 13.88 L m −2 h −1 bar −1 and an outstanding Li + /Mg 2+ separation factor of 85.64 in an equimolar mixed solution. Mechanistic analysis revealed that this precise fractionation is governed by the synergistic effects of strong electrostatic repulsion against divalent Mg 2+ and the lower hydration energy of monovalent Li + , which facilitates its rapid dehydration and permeation. This study provides an innovative and scalable strategy for designing high-performance NF membranes for lithium extraction.
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DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2026
·
IF 9.1
Yingying Chen,Wenhui Li,Jiawei Li,Yuanyuan Kong,Dan Hu,Xia Zhan,Xudong Feng,Yakai Lin
An amino-modified NF membrane is fabricated via integrating interfacial polymerization and chemical grafting. • Glycerol serves as a regulator to tailor the polyamide layer microstructure and surface amino group distribution. • Covalent grafting of AMH monomer endows the membrane surface with durable positive charge characteristics. • The membrane delivers a high water permeability of 14.0 L/m 2 ·h·bar and a MgCl 2 rejection rate of 96.21%. • A prominent Li + /Mg 2+ separation selectivity up to 34.27 is acquired under optimized preparation parameters. Polyamide nanofiltration (NF) membranes are generally hindered by the inherent trade-off between permeability and selectivity. To address the above drawbacks, this work constructs a high-performance positively charged NF membrane via a combined strategy of regulated interfacial polycondensation and covalent surface graft functionalization. Glycerol was blended into the aqueous monomer solution to tailor the growth process of polyamide (PA) selective layers; this treatment thinned the separation skin layer to boost water transport efficiency and meanwhile generated abundant hydroxyl reactive sites for subsequent grafting reactions. Under cerium ion-induced free radical polymerization, 2-[(2-methylacryloyl)oxy]ethanaminium (AMH) monomers were covalently immobilized on membrane surface via hydroxyl anchor points, endowing the membrane with persistent positive surface charges. A full set of material characterizations verified the successful grafting of AMH chains. The modified membrane exhibited a flattened surface structure with an average pore diameter of 0.61 nm, and the densified separation layer slightly weakened surface hydrophilicity. Under optimized fabrication parameters, the as-prepared membrane delivered outstanding separation performance: 96.21% MgCl 2 ion retention, a Mg 2+ /Li + separation factor of 34.27, and a water permeance of 14.0 L·m −2 ·h −1 ·bar −1 , which outperforms most NF membranes reported for brine lithium extraction. In addition, the membrane maintained steady separation capacity over a 72-h uninterrupted cross-flow filtration test, proving reliable long-term operational stability. This research provides an innovative fabrication route for high-throughput and high-selectivity NF membranes by coupling diffusion-controlled interfacial polymerization with directional surface functional grafting. Download: Download high-res image (190KB) Download: Download full-size image
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DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
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2026
·
IF 6.3
Weihua Ji,Ziqian Meng,Yang Miao,Yijie Wang,Chao Ma,Jeremy Heng Rao
The inherent contradiction between electrical and thermal transport has restricted the development of thermoelectric materials. However, high-entropy ceramics with complex structures exhibit unique properties and are expected to overcome this limitation. Herein, the thermoelectric properties of high-entropy fluorite oxides (Zr 0.194 Ce 0.194 Pr 0.194 Y 0.194 Ho 0.194 Mg x Zn 0.03-x )O 2-δ (0 ≤ x ≤ 0.03) are systematically tuned through the Mg-Zn co-doping strategy. The optimal composition (x=0.015) achieves a ZT of 0.46 at 773 K, which was approximately 119% higher than the undoped sample, and about 58% and 41% over Mg-only and Zn-only doped samples. This enhancement results from Zn increasing electrical conductivity as a charge donor while Mg reduces thermal conductivity through point defect scattering, enabling the synergistic optimization of electrical/thermal performance. First-principles calculations reveal Zn induces band convergence and gap contraction, increasing the density-of-states effective mass and promoting electron delocalization. This work validates high-entropy design combined with defect engineering as an effective strategy for developing high-performance thermoelectric materials.
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DOI
高影响因子
MINERALS ENGINEERING
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2026
·
IF 6
Wanting Yang,Chenxu Wang,Yuchen Shi,Hongchang Liu,Jun Wang
High Mg 2+ induces hydrophilic deposits that passivate malachite. • Mg 2+ deposition suppresses Cu–S film formation during sulfidization. • Mixed collectors improve malachite flotation in high-Mg 2+ recycled water. • XPS, SEM–EDS and ToF-SIMS reveal Mg coverage and Cu–S film evolution. The flotation recovery of malachite from complex polymetallic ores is often severely depressed by high concentrations of Mg 2+ in recycled water; however, the underlying mechanism and effective mitigation strategy remain unclear. In this study, microflotation experiments combined with surface characterization and spectroscopic analyses were conducted to elucidate the inhibitory role of Mg 2+ in malachite sulfidization flotation and to evaluate the performance of a mixed-collector system. The results showed that in the sodium hydrosulfide (NaHS)–potassium butyl xanthate/potassium amyl xanthate (PBX/PAX) system, increasing the Mg 2+ concentration from 0 to 100 mmol/L decreased malachite recovery by 37.13%. In contrast, the addition of benzohydroxamic acid (BHA) to the PBX/PAX system markedly improved flotation recovery under high-Mg 2+ conditions. Scanning electron microscopy coupled with energy-dispersive spectroscopy (SEM–EDS), zeta-potential, X-ray photoelectron spectroscopy (XPS), and time-of-flight secondary ion mass spectrometry (ToF-SIMS) revealed that Mg 2+ promoted the formation of a heterogeneous Mg(OH) 2 –Cu–S composite deposit layer on the malachite surface, which blocked active Cu sites and suppressed the formation of the Cu–S sulfidized film. Contact-angle and adsorption results further showed that the synergistic interaction between BHA and PBX/PAX accelerated and enhanced collector adsorption, leading to a more stable hydrophobic surface. Fourier transform infrared (FTIR) spectra indicated that xanthates chemisorbed on Cu–S sites through Cu–S–C bond formation, whereas BHA coordinated with surface Cu 2+ via Cu–O/N chelation. Their cooperative adsorption resulted in the formation of a Cu–S/Cu–O/N composite interfacial layer, which effectively alleviated Mg 2+ -induced surface passivation. These findings demonstrated that the mixed-collector system restored the hydrophobicity and flotation performance of malachite in high-Mg 2+ water through synergistic interfacial reconstruction.
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DOI
高影响因子
MICROCHEMICAL JOURNAL
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2026
·
IF 5.2
Duoshuang Xu,Jiacheng Dong,Yanhua Rao,Yongteng Long,Yanan Bie,Nannan Liu,Xingxing Tang
Development of a K + / Mg 2+ device : Silica nanowires were co‑functionalized with CB18C6 and EDTA to fabricate a CB18C6&EDTA/SiNWs/GMP ion selective device. • Improvement in selectivity : The synergistic effect of CB18C6 and EDTA greatly enhances K⁺/Mg²⁺ selectivity up to 331.16 compared with single ligand device. • K + Preferred Conductance : The fabricated device displays preferential K⁺ conductance in KCl and MgCl₂ mixed solution against varying Mg²⁺ concentrations. • Device Stability : The device keeps stable K⁺/Mg²⁺ selectivity under diverse ion concentrations and after long term storage. • Practical applicability : The K⁺/Mg²⁺ selectivity of the device is well maintained under simulated human body pH conditions. Biomimetic ion channels have attracted extensive attention for ion separation applications owing to their nanoscale or even sub-nanoscale confined structures, as well as the ease of surface functionalization. K + and Mg 2+ are indispensable biological ions involved in a wide range of physiological processes necessary for normal life activities. Due to the similar hydrated ionic radius and high water solubility of K + and Mg 2+ , it remains difficult to separate these ions using conventional materials. To address this challenge, herein we report a functionalized glass micropore (GMP) in which silica nanowires (SiNWs) were introduced into the GMP to serve as a supporting framework, followed by functionalization of the SiNWs with 4′-Carboxybenzo-18-crown-6 (CB18C6) and ethylenediaminetetraacetic acid (EDTA). The constructed functionalized GMP takes advantage of the excellent size matching between the cavity of CB18C6 and the radius of K + , together with the chelation effect of EDTA toward Mg 2+ . Through the synergistic effect of these two functional molecules, highly efficient ion sieving was achieved. Under the same solution volume conditions, the optimal selectivity was obtained when the mass ratio of CB18C6 to EDTA was 4:1, with the selectivities of K + / Na + , K + / Mg 2+ , and K + / Ca 2+ reaching 1.51, 331.16, and 98.16, respectively. The proposed functionalised GMP recognises K + based on the properties of the functional molecules, exhibiting excellent ion sieving performance between target ions and competing ions. This work provides a new research strategy for precise K + / Mg 2+ separation technology. Download: Download high-res image (134KB) Download: Download full-size image Schematic illustration of K + / Mg 2+ ion sieving in a functionalized GMP based on SiNWs, achieved through the synergistic effect of CB18C6 and EDTA. The diagrams are not drawn to scale.
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高影响因子
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