SEPARATION AND PURIFICATION TECHNOLOGY
·
2021
·
IF 7.312
Jingwei Kou,Houle Xiang,Zhen Zhang,Jing Zhang,Guiqin Wang,Kun Dai,Pengpeng Yang,Wei Zhuang,Hanjie Ying,Jinglan Wu
Ion exclusion chromatography (IEC) is an efficient technique used for the separation of strong electrolytes from weak electrolytes and nonelectrolytes. This work focuses on the assessment of mass transfer process and separation mechanism of H 2 SO 4 and Al 2 (SO 4 ) 3 on the strong base quaternary ammonium I anion exchange resin A-853E. A dynamic model for IEC was proposed and explicitly taken into account the Donnan equilibrium. The result showed that Donnan effect played a significant role in the mass transfer process of ionic species, which was interpreted as the inability of co-ion (Al 3+ ) to pass through Donnan membrane, while the counterion (SO 4 2- ) can enter resin pores due to electrostatic attraction. Meanwhile, a column model, based on Donnan equilibrium and cooperative adsorption isotherm , was then developed. The model successfully predicted the concentration profiles of mixed-ion (Al 3+ and SO 4 2- ) at the outlet of the fixed-bed in the dynamic separation process. The results indicated that the Al 3+ promoted the adsorption of SO 4 2- on the resin in view of presence of ‘concentration’ phenomenon. The separation mechanism of Al 3+ and SO 4 2- was presented combining model prediction and experimental results. Finally, the influence of three different valence states of metal ions (Na + , Fe 2+ , Al 3+ ) on the degree of H 2 SO 4 ‘concentration’ was investigated to further verify the Donnan effect.
研究领域:
化学工程
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分离科学
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DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2023
·
IF 9.5
Zhichao Li,Yu Zheng,Tianrun Gu,Xiangxuan Meng,Hui Wang,Kai Xu,Lijuan Cheng,Roni Kasher,Runnan Zhang,Zhongyi Jiang
Covalent organic frameworks (COFs) have emerged as advanced membrane materials for molecular separations, but it is rarely used for desalination due to the mismatch between the COFs pore size (1−5 nm) and the diameter of hydrated ions (<1 nm). Herein, we designed and fabricated an imide-linked TbTG COF membrane (COFM) with intrinsic sub-nano pores. The TbTG nanosheets were prepared by interfacial polymerization, and then self-assembled into COFMs on the porous PAN substrate. The sub-nano pore size (∼0.4 nm by simulation) conferred excellent size sieving capacity to the TbTG COFM with the molecular weight cut-off of only 180 Da, which was the lowest among COFMs ever reported. Moreover, the positive charge on the skeleton of TbTG COFM greatly fortified the Donnan effect. The TbTG COFM exhibits excellent salt rejections of 98.7% to Na 2 SO 4 , 99.1% to MgSO 4 , 99.5% to MgCl 2 and 93.3% to NaCl, respectively. The TbTG COFM also maintained high salt rejections under both high salt concentration up to 10000 ppm and high pH value of 9.4, showing great potential in seawater desalination applications.
研究领域:
材料科学
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环境工程
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产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2023
·
IF 9.5
Yi-Xing Sun,Jing Zhao,Xin-Zheng Li,Han Jiang,Ya-Juan Cai,Xu Yang,Yang Liu,Yi-Bo Li,Zi-Hao Yang,Ya-Ge Wu,Li-Ye Chen,Jing-Gang Gai
Covalent organic frameworks (COFs), with ordered pores and well-defined topology, are ideal materials for nanofiltration (NF) membranes because of their capacity of transcending the permeance/selectivity trade-off predicament. However, most reported COF-based membranes are focused on separating molecules with different sizes, resulting in low selectivity to similar molecules with different charges. Here, the negatively charged COF layer was fabricated in situ on a microporous support for the separation of molecules with different sizes and charges. Ultrahigh water permeance (216.56 L m–2 h–1 bar–1) was obtained because of the ordered pores and excellent hydrophilicity, which exceeds that of most membranes with similar rejections. For the first time, we used multifarious dyes with different sizes and charges, for the investigation of the selectivity behavior caused by the Donnan effect and size exclusion. The obtained membranes represent superior rejections to negatively and neutrally charged dyes larger than 1.3 nm, while positively charged dyes with a size of 1.6 nm can pass through the membrane, resulting in the separation of negative/positive mixed dyes with similar molecular sizes. This strategy of combining the Donnan effect and size exclusion in nanoporous materials may evolve into a generic platform for sophisticated separation.
研究领域:
材料科学
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分离技术
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纳米科技
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DOI
PubMed
高影响因子
Journal of Water Process Engineering
·
2022
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IF 7.34
Jun Xiang,Huan Li,Yunhao Hei,Guiying Tian,Lei Zhang,Penggao Cheng,Jianping Zhang,Na Tang
To solve water pollution induced by the electropositive dyeing wastewater, in this study, a loose electropositive nanofiltration (NF) membrane is prepared by the interfacial polymerization between self-prepared quaternized polyethyleneimine (QPEI) and 1,3,5-benzenetricarbonyl trichloride (TMC). Here the QPEI reduces the amine groups required for interfacial polymerization with high Zeta potential at the membrane surface. Meanwhile, the crosslinking reaction between QPEI and TMC is limited by steric hindrance effect, thus achieving a loose structure of the NF membranes. The obtained quaternized polyethyleneimine nanofiltration membranes (NF-QPEI) show a high selectivity based on Donnan effect. Rejections of divalent cations and common dyes are higher than 98%, with the excellent water flux of 8.21 L·m −2 ·h −1 ·bar −1 . Also, the membrane shows high operation stability for 36 h in dye separation test. Therefore, this work can provide a new strategy for the preparation of the electropositive NF membranes in term of dyeing wastewater separation.
研究领域:
环境科学
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材料科学
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产品关联
DOI
高影响因子
COLLOIDS AND SURFACES B-BIOINTERFACES
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2024
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IF 5.4
Lichun Chen,Yun Huang,Huimin Zhao,Songwen Xue
The physicochemical characteristics of fatty acid (FA) vesicles and their ion sensitivity as drug delivery vehicles in an ion-competitive environment have received much attention. Here, we show that in a Na + /K + competitive ionic environment, FA vesicles undergo a cascade of periodic expansion and selective ion retention in response to osmotic attack. When the Na + /K + ratio is altered, the expansion and volume of vesicles are affected and the ions in vesicles mix with the hyperosmotic fluid to produce a stable transmembrane potential, consistent with the Donnan effect and iontophoresis theory. Furthermore, osmotic swelling experiments suggest that FA vesicles are more easily maintained in a single Na + or K + solution than in a multicomponent ion competition system. As a theoretical basis for the utilization of FA vesicles in multicomponent ionic environments, we developed a core theoretical model to characterize the basic features of the volume fluctuations of FA vesicles in ion-competing environments.
研究领域:
生物物理学
·
药剂学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2024
·
IF 2.7
Jianming Wu,Qian Ma,Qingkai Pang,Qinjie Xu,Lihong Geng,Xiangfang Peng,Zhenming Chen,Peng Li,Yukun Chen
Given the toxicity of wastewater pollutants to both humans and the environment, it is critical to develop a new synthetic membrane with superior permeability and rejection. Herein, a novel asymmetric polyethersulfone (PES) composite filtration membrane was successfully prepared using a simple alternating vacuum-deposition process with positively charged chitosan and negatively charged cellulose nanofibrils as polycations and polyanions, respectively. As expected, the produced PES composite filtration membranes had a compressed and negatively charged surface, which prevented the anionic dye methyl blue (MB) molecules from infiltrating into the membrane matrix. Consequently, the resulting PES composite filtration membranes exhibited an extremely high MB rejection (99.7%) and a satisfactory flux (37.47 L h −1 m −2 MPa −1 ). In addition, the composite membrane demonstrated extremely selective removal of anionic dyes in the presence of neutral dyes due to the Donnan effect. Furthermore, the developed PES composite filtration membranes displayed exceptional long-term stability (99.8% rejection and 36.5 L h −1 m −2 MPa −1 flux after 50 h of filtration) and recycling properties (90.1% flux recovery rate after 3 cycles of running). In conclusion, the PES composite filtration membranes prepared in this study presented great potential in wastewater filtering.
研究领域:
环境科学
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材料科学
·
水处理
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产品关联
DOI
高影响因子
DESALINATION
·
2023
·
IF 9.9
Yongheng Yin,Yuemin Guang,Hongxiu Zhang,Qiying Xia,Chongbin Wang
The trade-off limit between permeability and selectivity , along with membrane fouling , has consistently posed significant challenges impeding the practical implementation of water purification membranes. In this paper, a combination of polyhedral oligomeric silsesquioxanes (POSS) and chitosan is introduced into the polyamide layer through interfacial polymerization and crosslinking to optimize the physical, chemical structure of membrane simultaneously. The resulting P/CS-2-POSS-2 membrane exhibits a notable water flux of 221.3 L m −2 h −1 MPa −1 and a substantial Na 2 SO 4 rejection of 97.1 %. The selectivity of water molecules over sulfates in the optimized hybrid membrane is approximately 4 times greater than that observed in the pristine polyamide membrane. This finding underscores the success of the developed method in mitigating the trade-off between permeability and selectivity. Furthermore, the hybrid membranes exhibit superior antifouling properties, as evidenced by an impressive flux recovery ratio of 95.8 % for bovine serum albumin. Additionally, the mass transport properties of the prepared membranes are explored via molecular dynamics (MD) simulations. The results highlight that chitosan primarily enhances the membrane's hydrophilicity , whereas POSS predominantly regulates the membrane's pore size. Both fillers synergistically enhance the comprehensive performance of the membrane by effectively utilizing steric hindrance and the Donnan effect .
研究领域:
材料科学
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环境工程
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水处理
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产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2025
·
IF 2.8
Yunping Wang,Chenlin Mu,Jingtao Bi,Mengmeng Sun,Yingying Zhao
The monovalent cation exchange membrane (MCEM) plays a crucial role in strategic resource recovery fields such as lithium/magnesium separation and seawater softening. This study proposes a two-stage modification strategy of “nanoparticle deposition – quaternization cross-linking”: first, deposit the Polypyrrole -Polyethyleneimine (PPY-PEI) composite nanoparticles in situ on the commercial Cation Exchange Membrane (CEM) surface, and then undergo quaternization cross-linking to prepare a high-performance monovalent cation exchange membrane (MCEM). The rigid structure of Polypyrrole -Polyethyleneimine (PPY-PEI) nanoparticles completely avoids the traditional problem of monomer penetration, and the rate of membrane pore blockage is significantly reduced. Electrified nanoparticles form gradient nanochannels to achieve dual mechanism synergy: The surface positive charge layer repels and blocks Mg 2+ through the Donnan effect; 2–5 nm mesoporous channels facilitate K + transport through size sieving. Subsequent quaternization crosslinking strengthened the modified layer and increased the positive membrane charge density, leading to further improvement in perm-selectivity. The results show that the modified membrane achieves a breakthrough performance in the separation of K + /Mg 2+ : the selectivity reaches 6.9; the K + flux remains at 0.14/(m 2 ·s). Molecular dynamic simulation of the ion diffusion behavior confirmed that the presence of Polypyrrole -Polyethyleneimine (PPY-PEI) can accelerate the diffusion rate of K + while limiting the transport of Mg 2+ , providing a theoretical basis for the performance prediction of selective ion exchange membranes.
研究领域:
膜科学与技术
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分离工程
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材料化学
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环境功能材料
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离子传输
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电化学
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资源回收
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2020
·
IF 7.183
Kaifeng Gu,Sichen Pang,BinBin Yang,Yanli Ji,Yong Zhou,Congjie Gao
The metal ions separation in acid wastewater is of great significance. Nanofiltration (NF) is an effective method to solve this problem. In this work, an acid-resistant PEI/BCMP NF membrane was obtained by chemically crosslinking polyethyleneimine (PEI) and 4,4′-Bis(chloromethyl)-1,1′-biphenyl (BCMP) on the polyethersulfone ultrafiltration (PESU) membrane. Concentration and heat treatment conditions for the membrane preparation were analyzed in detail. The PEI/BCMP membrane formed with 0.6% (m/v) PEI and 0.02% (m/v) BCMP at 80 °C for 10 min exhibited excellent performance. The membrane prepared in the state could be applied in acidic metal salt solutions. The Donnan effect caused the high selectivity for metal cations. At the same time, the loose structure improved the permeability. In the acidic (HCl) solution, the PEI/BCMP membrane showed a strong selectivity for metal ions (FeCl 3 99.5%, CuCl 2 92.2%, ZnCl 2 91.3%). After a long time operation, the membrane performance is still stable.
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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产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2023
·
IF 6.6
Xiaorui Wang,Shuang Wang,Han Sun,Chenglong Li,Feng Pan,Tongtong Gao,Yu Luo,Xiaojuan Wang,Zhe Wang
A series of innovative branching OPBI composite membranes (OPBI-BTZ-PIL) were created based on benzotriazole side chain grafted OPBI (OPBI-BTZ) and double-bond ionic liquids for vanadium redox flow battery applications. The benzotriazole contained three nitrogen sites, which helped enhance the proton conductivity and low area resistance. The cation in the polymeric ionic liquid in the matrix and the vanadium ion produces the Donnan effect , which reduces vanadium permeability. Moreover, the hydrogen bond cross-linking network formed by the polymeric ionic liquid in the membrane further helps proton transport. The vanadium permeability of OPBI-BTZ 10 -PIL 10 is as low as 1.51 × 10 −9 cm 2 min −1 , which is one 40th of the Nafion117 (62.54 × 10 −9 cm 2 min −1 ). Its ion selectivity is up to 2.45 × 10 6 S min cm −3 . The OPBI-BTZ 10 -PIL 10 membrane performs well at 60 mA cm −2 , with CE of 94.12% and EE of 86.2%, both of which are higher than the Nafion117 membrane.
研究领域:
材料科学
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电化学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2024
·Vol. 35
·期 1
·e6250
·
IF 3.1
Yangyang Wang,Hongding Yan,Mengxu Ma,Chenkai Zhou,Qian Hou,Zehong Xu,Min Xia,Huagang Ni,Yanrong Jia,Peng Ye
Electrostatic effect and Donnan effect could effectively improve the separation performance of nanofiltration membrane. Polyions were grafted from graphene oxide (GO) nanosheets to prepare the nanofiltration membrane, and the electrostatic effect and Donnan effect in the membrane pores could be greatly improved. The GO was modified by introducing double bonds. Then, polyanionic poly(acrylic acid) (PAA) and polycationic diallyldimethylammonium chloride (PDDA) were grafted from GO nanosheets, which were employed to fabricate the nanofiltration membranes, respectively. Therefore, nanofiltration membranes GO-PAA and GO-PDDA with cross-linked structure and pH responsiveness were prepared. The separation effect of the anionic dyes was over 99%, and the membrane had perfect adsorption effect on cationic dyes. The cross-linked structure formed between GO nanosheets inhibited the change of the interlayer spacing of the nanofiltration membrane. The conformation of the graft chains could be adjusted by the pH value of the solution, by adjusting the size of the nanochannel. The rejection rates of the nanofiltration membranes for the cationic dyes could reach more than 98%, and the membrane had perfect adsorption effect on anionic dyes. Similar to the grafted polyanion, the grafted polycation also formed a cross-linked structure between the graphene nanosheets, thereby inhibiting the change of the nanochannels with the pH value to a certain extent. Polyionic nanofiltration membranes have excellent selectivity and could be widely used in the treatment of dye wastewater and other fields.
研究领域:
材料科学
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环境工程
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纳米技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2020
·
IF 7.183
Caini Liu,Wenyi Wang,Liuyong Zhu,Fangyan Cui,Chengcheng Xie,Xingyu Chen,Ning Li
A structurally controlled polyethersulfone (PES) membrane, as the substrate of the thin film composite nanofiltration (NF) membranes, was designed and fabricated with aligned carbon nanotubes (ACNTs) by a direct current electric field. The morphology and properties of the NF membranes were simultaneously affected by the PES substrate with especial macrovoids and ACNTs, increasing the permeability from 6.4 to 29.7 L/m 2 h bar. It was confirmed by FT-IR and XPS that the poly(piperazine amide) selective layer of the modified NF membrane has an increased content of –COOH for enhanced hydrophilicity. The zeta potential proves that the surface of the NF membrane modified by electric field has weaker negative charge than that of unmodified membrane in the range of pH = 5–9. Under the combined action of the Donnan effect and size exclusion, the rejection of MgCl 2 increased while maintaining the dianion rejection above 95%. Particularly, the NF membrane modified with ACNTs exhibited better chlorine resistance and antifouling ability, thus improving the stability and perdurability of membranes. Our work utilizes the characteristics of ACNTs to explore its potential in NF membranes.
研究领域:
材料科学
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化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）