SEPARATION AND PURIFICATION TECHNOLOGY
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2023
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IF 8.6
Hongying Li,Fei Shi,Shuhui Chen,Yifan Li
Two Dimensional membranes, which are usually constructed by inorganic nanosheets, have shown great potentials in efficient separation of low-molecular-weight chemicals. In this study, a novel type of organic–inorganic hybrid two-dimensional membrane is designed and prepared by co-assembly of a two-dimensional organic building block, Dopa thin-walled microcapsule, and a typical inorganic nanosheet, MXene. The introduction of MXene not only increases the distance between adjacent Dopa microcapsules and improves the solvent flux of the membrane, but also improves the structural stability by modulating the chelation strength of MXene with the Dopa microcapsules. The optimal Dopa/MXene composite membrane shows good performance in the field of organic solvent nanofiltration (OSN), with a flux of 723 L m −2 h −1 bar −1 for methanol and reactive black rejection of more than 90%. All the Dopa/MXene hybrid membranes show better stability than MXene lamellar membranes and MXene/Dopa hybrid membranes (where Dopa microcapsule is inserted into MXene membrane), demonstrating the advantages of organic species in enhancing interfacial adhesion. More interestingly, since the chelation between Dopa and MXene mainly depends on the presence of TiO 2 in MXene, the oxidation of MXene, which often raises concerns of instability, herein is found to further increase the rejection and stability of Dopa/MXene hybrid membranes with only slight decrease of solvent flux.
研究领域:
材料科学
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分离技术
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纳米科技
✓ 已验证
产品关联
DOI
高影响因子
ACS Omega
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2021
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IF 3.512
Qianqian Tian,Wenrui Mu,Fei Shi,Yifan Li
Thin-film nanocomposite membranes have shown great promise in organic solvent nanofiltration. However, it is challenging to acquire high permeation flux without severe swelling, which might do harm to rejection and long-term stability. In this study, we introduced dopamine-modified mesoporous silica nanoparticles into the polyamide (PA) matrix via interfacial polymerization to fabricate a series of thin-film nanocomposite membranes. By using polyethyleneimine (PEI) as the aqueous monomer, the modified nanoparticles are designed to be cross-linked within the PA network, which allows the penetration of PEI into the mesopores, and therefore, the membranes show better resistance to solvent-induced swelling and pressure-induced densification. More importantly, the mesopores of nanoparticles provide additional fast channels for solvents, resulting in an unusual enhancement of solvent flux under reduced membrane swelling. Along with the permeation flux, the rejection performance of the nanocomposite membranes is simultaneously improved, thanks to the controlled swelling arising from the strong interfacial adhesion. Thin-film nanocomposite membranes with optimal filler concentration exhibit a high isopropanol permeance of 8.47 L m–2 h–1 bar–1 as well as a quite low-molecular-weight cutoff of 281 Da.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2024
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IF 8.1
Weilin Feng,Lu Xu,Yuji Chen,Jiaqi Li,Hukang Guo,Mengxiao Zhang,Xiaohe Wang,Jianyu Wang,Chuanjie Fang,Liping Zhu
Integrally-skinned asymmetric (ISA) polymer membranes show enormous potential in efficiently energy-saving organic solvent nanofiltration (OSN) due to their excellent structural stability. However, the control of their microstructures at the nanoscale is technically challenging, making it difficult to simultaneously achieve high separation resolution and high solvent permeance. In this work, we report the in-situ evolution of polyimide ISA membranes from ultrafiltration to nanofiltration through thermal-induced densification of the surfaces. This process was attributed to the surface dynamics of polymers — i.e., the polymer segments on surface are more freely movable than that in bulk. The optimum treatment temperature was located between the glass transition temperatures of surface and bulk, which were measured based on porosity changes. The as-prepared ISA membranes with thin and dense skin layers exhibited high solvent permeance (e.g., over 5 L m −2 h −1 bar −1 for ethanol) and favorable molecular weight cut-off of around 300 Da. The membranes rivaled the state-of-the-art thin film composite membranes, demonstrating great potential in fast and precise molecular separation in OSN.
研究领域:
材料科学
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化学工程
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膜技术
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Polymer Materials
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2023
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IF 5
Liping Liang,Yuanqi Wang,Weirong Ren,Xinpei Gao,Liqiang Zheng,Fei Lu
Ionic liquid (IL)-based aqueous two-phase systems (ATPSs) are formed by the phase separation of aqueous mixture of ILs. Owing to their unique interfacial properties and stable interfacial zone, IL-based ATPSs can work as a promising confined space for membrane processing. Herein, for the first time, we proposed the thermoresponsive IL-based ATPSs as a platform for synthesizing covalent organic framework (COF) membranes. Upon the formation of aqueous biphasic interface at a corresponding temperature, the monomers and catalysts were separately dispersed in the IL-rich phase and water-rich phase. Due to the high viscosity of IL-rich phase and hydrogen bonding interactions in water-rich phase, the diffusion of both aldehyde and amine monomers could be controlled simultaneously and react within the aqueous biphasic interface zone. By optimizing the interfacial properties, the tight and crystalline COF membranes can be achieved with ultrahigh solvent flux and exceptional dye retention performance (>98.0%). For comparison, the homogeneous IL solution realized by temperature without affecting the integrity of the biphasic system was also applied as the medium for COF synthesis and only COF powders with low crystallinity can be obtained. As the pioneering exploitation to fabricate COF membrane at the IL-based aqueous biphasic interface, this work would supply a guiding direction for the green membrane processing strategy.
研究领域:
材料科学
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化学工程
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膜技术
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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
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2024
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IF 8.4
Ni-Jie Liu,Jun-Yan Yu,Xing-Yu Chen,Li-Fen Liu
Organic solvent ultrafiltration (OSU) membrane as the crucial supporting layer of thin-film composite (TFC) organic solvent nanofiltration (OSN) membrane can help the OSN technology to satisfy the rapidly growing demand for small-molecular separation and purification in organic solvent systems. Aiming at the two main bottlenecks of poor tolerance to strong polar solvents and low solvent flux of the conventional commercial polyimide (PI) ultrafiltration (UF) membrane, in this study, a facile method was proposed to prepare a novel polyimide/polyethyleneimine@TiO2 (PI/PEI@TiO2) OSU membrane with improved solvent resistance and permeability by synchronously coupling the non-solvent-induced phase transformation (NIPs), chemical crosslinking and interfacial in-situ biomineralization. Dut to the chemical crosslinking between PEI and PI, the PI/PEI@TiO2 membrane exhibited good resistance to more organic solvents including the strong polar aprotic solvents (e.g., DMF, NMP and DMSO), ordinary polar solvents (e.g., ethanol) and nonpolar solvents (e.g., n-hexane). At the same time, PEI synchronously catalyzed Ti-BALDH to in-situ generate the TiO2 nanoparticles via interfacial biomineralization, which improved the solvent flux of the PI/PEI@TiO2 membrane due to the creation of more channels and promoted the compatibility of TiO2 within PI/PEI matrix. Especially, the PI/PEI@TiO2-5 membrane with 5 wt% TiO2 loading showed the optimal solvent resistance and high flux in strong polar aprotic solvents (>50 L m−2 h−1·bar −1 in DMF). Therefore, the resultant new PI/PEI@TiO 2 OSU membrane will have a promising separation application in the organic solvent systems in the future.
研究领域:
材料科学
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化学工程
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膜技术
✓ 已验证
DOI
高影响因子
EUROPEAN POLYMER JOURNAL
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2023
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IF 6
Yanqing Qu,Yuxin Zha,Hongge Jia,Yu Zang,Yang Liu,Tong Gu,Xiaoyu Du
Covalent organic frameworks (COFs), with high porosity, uniform and tunable pore size, which are advantageous to prepare defect-free membranes with high separation performance and high permeability, and have achieved efficient applications in the field of separation membranes in numerous directions. According to our knowledge, the transition metal ion (Cu 2+ ) which is used in Schiff base condensation reaction has been rarely described. Herein, we report the interfacial polymerization of ternary amines and binary aldehyde monomers via the catalyst Cu(ClO 4 ) 2 ·6H 2 O. In this work, we report the fabrication of covalent organic framework films from four different functional structure monomers by using the transition metal ion-catalyzed interfacial polymerization at room temperature. The four as-synthesized films are flexible, continuous, defect-free and have large areas, which have excellent performance in the direction of dye separation as well as solvent penetration. After the COF films were transferred to the polyethersulfone support, the composite films exhibited enhance the rejection of methylene blue (98.43%), high-water flux (81.46 L m −2 h −1 bar −1 ) and solvent flux (ethanol (13.03 L m −2 h −1 bar −1 ), acetonitrile (50.38 L m −2 h −1 bar −1 )). The large area, tunable pore size, and tailored molecular composite membranes show potential for nanofiltration applications.
研究领域:
材料科学
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化学工程
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膜技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
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2015
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IF 5.056
Yan Chao Xu,Xi Quan Cheng,Jun Long,Lu Shao
The main drawback of polyimide (PI) based OSN membrane capable to separate molecules is the declined solvent permeance after crosslinking. In this study, the hydrophilic monoamine named as Tris(hydroxymethyl) aminomethane (Tris) was first utilized to modify polyimide OSN membranes by adding Tris into the dope solution before phase inversion and diamino crosslinking for improving membrane-solvent mutual affinity so as to obtain high-performance OSN membranes. Such Tris modified membranes were proved by chemical characterizations, and the further contact angles and surface energy measurements revealed that the hydrophilicity and surface energy of the novel membranes increased with the Tris loading. Interestingly, the morphological observation demonstrated that the macrovoids shown in the pristine membranes can be completely displaced by sponge-like pores in Tris modified membranes. Surprisingly, the isopropanol (IPA) permeance of 10% Tris modified crosslinked membranes increased to 270% of the original value with only slight decline in dyes rejections. Besides, the fundamental study on the relationship between IPA or N,N-dimethylformamide (DMF) permeance and the membrane-solvent solubility parameter distance were performed. Our novel monoamine modification strategy can provide a new incentive to develop advanced membranes applicable to aqueous solution separation, gas separation and pervaporation for future sustainable usages.
研究领域:
材料科学
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化学工程
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膜技术
·
可持续分离
✓ 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）