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ISSN : 1226-0088(Print)
ISSN : 2288-7253(Online)
Membrane Journal Vol.33 No.4 pp.149-157
DOI : https://doi.org/10.14579/MEMBRANE_JOURNAL.2023.33.4.149

Covalent Organic Framework Based Composite Separation Membrane: A Review

Jeong Hwan Shim*, Rajkumar Patel**†
*Nano Science and Engineering, Underwood International College, Yonsei University, Incheon 21983, Korea
**Energy and Environmental Science and Engineering, Integrated Science and Engineering Division, Underwood International College, Yonsei University, Incheon 21983, Korea
†Corresponding author(e-mail: rajkumar@yonsei.ac.kr; http://orcid.org/0000-0002-3820-141X)
August 17, 2023 ; ; August 23, 2023

Abstract


Covalent organic frameworks (COFs) have shown promise in various applications, including molecular separation, dye separation, gas separation, filtration, and desalination. Integrating COFs into membranes enhances permeability, selectivity, and stability, improving separation processes. Combining COFs with single-walled carbon nanotubes (SWCNT) creates nanocomposite membranes with high permeability and stability, ideal for dye separation. Incorporating COFs into polyamide (PA) membranes improves permeability and selectivity through a synthetic interfacial strategy. Three-dimensional COF fillers in mixed-matrix membranes (MMMs) enhance CO2/CH4 separation, making them suitable for biogas upgrading. All-nanoporous composite (ANC) membranes, which combine COFs and metal-organic framework (MOF) membranes, overcome permeance-selectivity trade-offs, significantly improving gas permeance. Computational simulations using hypothetical COFs (hypoCOFs) demonstrate superior CO2 selectivity and working capacity relevant for CO2 separation and H2 purification. COFs integrated into thin-film composite (TFC) and polysulfonamide (PSA) membranes enhance rejection performance for organic contaminants, salt contaminants, and heavy metal ions, improving separation capabilities. TpPa-SO3H/PAN covalent organic framework membranes (COFMs) exhibited superior desalination performance compared to traditional polyamide membranes by utilizing charged groups to enable efficient desalination through electrostatic repulsion, suggesting their potential for ionic and molecular separations. These findings highlight COFs' potential in membrane technology for enhanced separation processes by improving permeability, selectivity, and stability. In this review, COF applied for the separation process is discussed.


covalent organic frameworks , membranes , permeability , selectivity , stability , separation processes

공유 유기 골격체 기반 복합 분리막 : 고찰

심 정 환*, 라즈쿠마 파텔**†
*연세대학교 언더우드국제대학 융합과학공학부 나노과학공학
**연세대학교 언더우드학부 융합과학공학부 에너지환경융합전공

초록


공유 유기 프레임워크(COF)는 분자 분리, 염료 분리, 가스 분리, 여과 및 담수화를 포함한 다양한 응용 분야에서 가능성을 보여주었습니다. COF를 막에 통합하면 투과성, 선택성 및 안정성이 향상되어 분리 공정이 향상됩니다. 단일 벽 탄 소 나노튜브(SWCNT)와 COF를 결합하면 염료 분리에 이상적인 높은 투과성과 안정성을 가진 나노 복합막을 생성합니다. COF를 폴리아미드(PA) 막에 통합하면 합성 계면 전략을 통해 투과성과 선택성이 향상됩니다. 혼합 매트릭스 막(MMM)의 3 차원 COF 필러는 CO2/CH4 분리를 향상시켜 바이오가스 업그레이드에 적합합니다. COF와 금속 유기 프레임워크(MOF) 막 을 결합한 모든 나노 다공성 복합재(ANC) 막은 투과성-선택성 트레이드오프를 극복하여 가스 투과성을 크게 향상시킵니다. 가상 COF (hypoCOF)를 사용한 계산 시뮬레이션은 CO2 분리 및 H2 정제와 관련하여 우수한 CO2 선택성과 작업 능력을 입 증합니다. 박막 복합재(TFC) 및 폴리술폰아미드(PSA) 막에 통합된 COF는 유기 오염물, 염 오염물 및 중금속 이온에 대한 거 부 성능을 향상시켜 분리 능력을 향상시킵니다. TpPa-SO3H/PAN 공유 유기 프레임워크 막(COFM)은 대전된 그룹을 활용하 여 정전기적 반발을 통해 효율적인 담수화를 가능하게 함으로써 기존의 폴리아미드 막에 비해 우수한 담수화 성능을 보여 이 온 및 분자 분리의 잠재력을 제시했습니다. 이러한 연구 결과는 투과성, 선택성 및 안정성을 향상시켜 향상된 분리 공정을 위 한 막 기술에서 COF의 잠재력을 강조합니다. 이 검토에서는 분리 공정에 적용된 COF에 대해 논의합니다.


    1. Introduction

    A covalent organic framework (COF) is a new type of crystalline polymer with 2D and 3D structures prepared from organic building blocks connected through covalent bonds. The properties of the COF can be tuned by choosing a suitable monomer[1,2]. Membranebased technology for separation processes such as gas or liquid is well-established. Various kinds of rigid polymers or copolymers with elastomeric materials are used as membrane materials, but selectivity, permeability, and long-term usability are challenging to improve simultaneously. The incorporation of crystalline materials like metal-organic framework (MOF) improves the glass transition of the composite membrane and separation efficiency[3-8].

    Pollution of air, shortage of clean energy, and water scarcity are the most difficult challenges humanity faces. Membrane-based separation technologies, particularly nanofiltration (NF) membranes, have gained popularity in addressing global environmental challenges related to water treatment[7,8]. However, current NF membranes face a trade-off between permeability and selectivity, necessitating the development of ultrathin polymer nanofilms to enhance water permeance. Traditional polymer materials used in membrane fabrication often result in membranes with non-uniform pore sizes and limited surface porosity, leading to inadequate selectivity and permeating flux[5].

    To overcome these limitations, researchers are exploring the use of novel materials with uniform pore sizes and enhanced porosity, such as covalent organic frameworks (COFs), which offer advantages like low mass density, permanent porous structure, large surface area, and customizable chemical structure[6-8]. COFs show promise in various applications, including adsorption, catalysis, energy storage, and separation, due to their well-ordered pore structure, uniform pore size distribution, excellent stability, and resistance to organic solvents. In particular, COFs hold the potential for precise separation membranes and oil-water separation[9]. Furthermore, in membrane-based CO2/CH4 separation, COFs are being considered as fillers in mixed-matrix membranes (MMMs) to improve membrane performance and overcome the permeability-selectivity trade-off commonly faced by polymeric materials[10-15]. Overall, COFs exhibit a versatile solution for enhancing membrane technology and addressing the challenges associated with water treatment, gas separation, and organic solvent filtration, which is reviewed in this review.

    2. Gas Separation

    Hypothetical covalent organic frameworks (hypoCOFs) can design high-performance materials for CO2 separation and H2 purification[16]. A computationally guided screening approach using grand canonical Monte Carlo (GCMC) simulations and density functional theory (DFT) calculations was implemented to evaluate the separation performance of hypoCOFs. The role of linker fragments in influencing the interaction between CO2, H2, and the linkers was highlighted through DFT calculations. The results show that hypoCOFs exhibit enhanced CO2 selectivities and working capacities compared to experimentally synthesized COFs in pressure- swing adsorption (PSA) and vacuum-swing adsorption (VSA) processes. The strength of hydrogen bonding between CO2 and the functional groups of linkers was identified as a crucial factor influencing the CO2 selectivity of hypoCOFs. Molecular dynamics (MD) simulations demonstrated that hypoCOFs outperform COFs, zeolites, metal organic frameworks (MOFs), and polymer membranes in terms of CO2 selectivity, working capacity, and H2 permeability. The computed adsorption performance scores (APSs) of hypoCOFs were significantly higher than those of experimentally synthesized COFs, indicating their potential as adsorbents and membranes for CO2 capture and H2 purification.

    Fabrication of all-nanoporous composite (ANC) membranes can be achieved by incorporating covalent organic framework (COF-TpPa-1) and metal organic framework (ZIF-9) membranes to improve gas permeance while maintaining selectivity[17]. Traditional MOF membranes have high selectivity but suffer from low gas permeance due to their narrow channels and ultra-small pore sizes. To address this limitation, COFs with large and uniform pores are incorporated into the MOF membrane to enhance gas permeance. The ANC approach offers a promising solution to overcome the permeance-selectivity trade-off commonly encountered in membrane-based gas separations. The fabrication process involves combining ball-milled COF particles with a metal gel to form a precursor membrane. This precursor membrane is then treated with MOF ligand vapor in a gas-phase transformation process. The interaction between the COF, MOF, and metal gel components leads to the development of a well-defined nanoporous structure with improved gas separation properties. The incorporation of COF into the MOF membrane through the ANC approach significantly enhances gas permeance. The resulting COF/MOF ANC membranes exhibit a substantial increase in gas permeance, with the composite membrane achieving a gas permeance of 551 gas permeation units (GPU) compared to 22 GPU for the pristine MOF membrane. This enhancement in gas permeance is attributed to the reduced effective membrane thickness achieved by doping COF into the MOF membrane.

    Preparation of composite membranes by combining covalent organic frameworks (COFs) and metal-organic frameworks (MOFs) was reported to achieve superior gas separation performance[18].

    The unique properties of COFs and MOFs, such as high surface areas, porosities, and chemical functionalities, make them suitable for molecular-sieving membranes. The article introduces a novel strategy that utilizes a three-dimensional (3D) MOF-mediated approach to fabricate composite membranes based on two-dimensional (2D) COFs. The MOF film acts as a binding site to anchor the 2D COF building units, enabling the construction of composite membranes. Factors like chemical synergy, functionality, spatial arrangement, interlayer chemistry, and crystallographic orientation play crucial roles in achieving successful membrane performance. The resulting composite membrane, composed of a 2D H2P-DHPh COF layer and UiO-66 MOF, demonstrates remarkable gas separation properties. It exhibits high selectivity for H2/CO2 gas mixtures, surpasses the Robeson upper bound, and outperforms previously reported polymer membranes in terms of H2 and CO2 permeability.

    Yang et al. focuses on the development of mixedmatrix membranes (MMMs) utilizing a three-dimensional covalent organic framework (3D-COF) as a filler material to enhance CO2/CH4 separation[19]. The performance of MMMs is significantly influenced by the physicochemical properties of the 3D-COF filler. The 3D-COF possesses a large surface area, high porosity, and strong affinity for CO2, which enhances the CO2 permeability and CO2/CH4 selectivity of the MMMs when integrated into a polyimide matrix. The 3D morphology, surface area, and porosity of the filler contribute to improved hydrogen bonding with the polymer matrix, increasing the rigidity of the polymer chains and preventing the collapse of free volume over time. The MMMs loaded with 3D-COF filler demonstrate significant enhancements in CO2 permeability (57% at 10% loading and 140% at 15% loading) while maintaining better CO2/CH4 selectivity. The 3D-COF filler also effectively retards the aging process of the MMMs, preserving 97% of their initial membrane performance after a 240-day aging period compared to the pristine membrane's 70% retention. These findings suggest that controlling the morphology of COF fillers holds promise for creating high-performance MMMs suitable for applications like biogas upgrading.

    3. Oil/Water Separation

    The novel adsorbent, polyacrylonitrile (PAN)/covalent organic framework TpPa-1 nanofiber, is introduced for the dispersive solid-phase extraction (dSPE) of quinolone antibiotics (QAs) in honey and pork samples. The PAN/TpPa-1 nanofiber is synthesized using electrospinning and characterized for its structure and morphology[ 20].

    Optimal conditions for the extraction and desorption of the target analytes are determined. The PAN/TpPa-1 nanofiber is then combined with high-performance liquid chromatography (HPLC) to establish a sensitive detection method for five QAs. The PAN/TpPa-1 nanofiber- based dSPE, in combination with HPLC-UV detection, proves to be a reliable and efficient method for the extraction and determination of QAs in complex samples. The nanofiber demonstrates good reusability and ease of operation. The developed method shows excellent linearity, low limits of detection, satisfactory precision, and acceptable recovery rates for the QAs in honey and pork samples. The exceptional extraction performance of the PAN/TpPa-1 nanofiber can be attributed to the interactions such as π-π interactions and hydrogen bonding.

    Chen et al. prepared a nanofiber membrane coated with COFs by dip coating techniques[21]. COF-COOH was mixed with dopamine and coated onto the polyvinylidene membrane by one step process. Fig. 3 represent the membrane surface behavior.

    Presence of abundant function group on the surface of the membrane induce superhydrophilicity and in underwater its behave as superolephobic which is reflected by extremely low contract angle of 15°. The resulting composite membrane shows very high oil rejection of above 98% and water flux of 1843.48 L/m2 h bar. Liu et al. developed a fluorinated COF on a membrane support to prepare a superhydropobic surface with properties exactly opposite to previously reported membrane[22].

    4. Nanofiltration

    A novel interfacial bridging strategy is introduced for fabricating nanocomposite membranes based on polyamide (PA) by incorporating a covalent organic framework (COF) as a filler material[23]. The COF, TAPB-BPTA, was synthesized and grafted with cysteine (CYS) to enhance dispersion and adhesion. The COF was then copolymerized with trimesoyl chloride (TMC) to create a defect-free crosslinked top skin layer. The interfacial bridging approach, using COF, polyethyleneimine (PEI), and TMC, ensured interfacial compatibility and prevented particle aggregation. The introduction of the CYS bridge improved the interfacial adhesion between the COF and PA. The PA/COF-C membrane exhibited enhanced permeability and selectivity due to the perforative transmissions and selectivity gaps within the matrix. The addition of grafted COF particles improved dispersion and prevented aggregation. The resulting PA/COF-C(1.2) membrane demonstrated high water permeance, competitive rejection rates, and remarkable stability during multi- cycle separation. The PA/COF nanocomposite membrane prepared using this strategy holds promise for wastewater purification, offering improved permeability, selectivity, and stability in applications such as dyes and antibiotics removal.

    The article reports on the incorporation of iminelinked covalent organic framework (COF) films into thin-film composite (TFC) membranes for water treatment applications. Three different COF films were synthesized and incorporated into TFC membranes with a polyacrylonitrile (PAN) support[24].

    The COF films exhibited variations in pore size reduction due to different substituents. The TFC membrane with the TAPB-PDA-Et COF film demonstrated the highest rejection performance. The membranes with TAPB-PDA-Me and TAPB-PDA-Et showed improved rejection of organic and salt contaminants compared to the TAPB-PDA-H membrane. The permeation behavior was analyzed using a solution-diffusion model, revealing a systematic difference in rejection with increased pendant group length. The successful incorporation of COF films into TFC membranes was achieved through an interfacial polymerization method. The findings highlight the importance of structural design and the potential for optimizing membrane performance through rational modifications.

    Researcher focuses on the development of nanocomposite membranes for the effective removal of heavy metal ions from acid wastewater[25].

    Triazine-structured covalent organic frameworks (COFs) called NENP-1 are incorporated into polysulfonamide (PSA) membranes through interfacial polymerization. The addition of NENP-1 improves the hydrophilicity and positive charge properties of the membrane, enhancing its water permeation and heavy metal ion rejection capabilities. The presence of NENP-1 also creates suitable pore sizes for selectively removing inorganic salts. The covalent linkage between NENP-1 and the PSA matrix improves membrane compatibility and stability. The NENP-1-PSA/PES membranes demonstrate significant improvements in water flux and rejection of ions compared to pristine PSA membranes. The membranes exhibit good stability in acidic conditions and show excellent separation performance for heavy metal salts and calcium chloride. The interaction between NENP-1 and the matrix during interfacial polymerization ensures the construction of structurally stable membranes with long-term operation capabilities and stability in acidic conditions.

    The use of TpPa-SO3H/PAN covalent organic framework membranes (COFMs) is introduced for efficient desalination. A counter diffusion method is introduced, utilizing pre-assembled TpPa-SO3H nanosheets as a seeding layer to regulate the growth of TpPa-SO3H COFs within the membranes[26]. This approach improves structural integrity and controls the seeding layer thickness. TpPa-SO3H/PAN COFMs demonstrate excellent desalination performance, with a high Na2SO4 rejection rate of 97.4%. These COFMs outperform conventional polyamide membranes, particularly at high salt concentrations up to 10,000 ppm. They maintain superior performance in removing salts even in challenging conditions.The charged groups on the channel walls of TpPa-SO3H/PAN COFMs enhance the electrostatic repulsion mechanism, facilitating efficient desalination. The study highlights the significant impact of the seeding layer thickness on COFM growth and desalination performance. The proposed method provides a promising platform for fabricating efficient COFMs and other microporous membranes for ionic and molecular separations.

    5. Conclusions

    The review discusses the development of covalent organic framework (COF)-based membranes for efficient separation in various applications. The nanocomposite membrane combining SWCNT and COF showed high permeability and stability in organic solvents, particularly for dye separation. COFs integrated into PA membranes improved molecular separation, while COF-modulated TFN membranes showed enhanced permeability and selectivity. 3D-COF as a filler material in MMMs enhanced CO2/CH4 separation. Computational simulations of hypoCOFs demonstrated enhanced CO2 selectivity. PAN/COF nanofibers exhibited excellent extraction performance for antibiotics. COFs in PA membranes improved water treatment. COF films in TFC membranes enhanced rejection performance. Triazine-structured COFs improved water permeation and heavy metal ion rejection. TpPa-SO3H/PAN COFMs demonstrated excellent desalination performance. COFs offer the potential for various separation applications, improving permeability, selectivity, and stability.

    Figures

    MEMBRANE_JOURNAL-33-4-149_F1.gif

    Process flowchart illustrating the fabrication of a H2P-DHPh COF–UiO-66 composite membrane by controlling the growth of 2D COF crystals along the ab (lateral) direction as well as maintaining the orientation of the COF channels along the c (vertical) direction (Zr: cyan; O: red; N: blue; C: gray. H atoms are excluded for clarity) (Reproduced with permission from Das et al.[18], Copyright 2020, American Chemical Society).

    MEMBRANE_JOURNAL-33-4-149_F2.gif

    Process of Electrospinning (A); Synthesis of PAN-Tp and PAN-TPA Nanofibers and In Situ Generation of COFs on Nanofibers and Synthesis of Hydrophobic PAN/COF Nanofibers (B) (Reproduced with permission from Chen et al.[20], Copyright 2022, American Chemical Society).

    MEMBRANE_JOURNAL-33-4-149_F3.gif

    (a) Dynamic underwater DCM-adhesion experiment on COF0.2/DA2-2. (b) Rolling contact test of DCM on COF0.2/DA2-2. (c) Images recording the excellent antifouling property of COF0.2/DA2-2; n-hexane (top four images) and DCM (bottom four images) were injected onto the membrane by a syringe, respectively (Reproduced with permission from Liang et al.[21], Copyright 2022, American Chemical Society).

    MEMBRANE_JOURNAL-33-4-149_F4.gif

    Synthesis of TAPB-PDA-R and Models of Each COF Pore with Corresponding Measured Pore Width (Reproduced with permission from Corcos et al.[18], Copyright 2019, American Chemical Society).

    MEMBRANE_JOURNAL-33-4-149_F5.gif

    Schematic preparation of NENP-1-PSA/PES nanocomposite membranes (Reproduced with permission from Wang et al.[25], Copyright 2020, American Chemical Society).

    Tables

    References

    1. S. Das, J. Feng, and W. Wang, “Covalent organic frameworks in separation”, Annu. Rev. Chem. Biomol. Eng., 11, 131 (2020).
    2. P. J. Waller, F. Gándara, and O. M. Yaghi, “Chemistry of covalent organic frameworks”, Acc. Chem. Res., 48, 3053 (2015).
    3. S. Yuan, X. Li, J. Zhu, G. Zhang, P. Van Puyvelde, and B. Van Der Bruggen, “Covalent organic frameworks for membrane separation”, Chem. Soc. Rev., 48, 2665 (2019).
    4. M. Matsumoto, L. Valentino, G. M. Stiehl, H. B. Balch, A. R. Corcos, F. Wang, D. C. Ralph, B. J. Mariñas, and W. R. Dichtel, “Lewis-acid-catalyzed interfacial polymerization of covalent organic framework films”, Chem, 4, 308 (2018).
    5. X. Sui, Y. Wang, F. Liu, Z. Yuan, C. Wang, Y. Yu, K. Zhou, K. Goh, and Y. Chen, “The tripartite role of 2D covalent organic frameworks in graphene- based organic solvent nanofiltration membranes”, Matter, 4, 2953 (2021).
    6. L. Valentino, M. Matsumoto, W. R. Dichtel, and B. J. Marinas, “Development and performance characterization of a polyimine covalent organic framework thin-film composite nanofiltration membrane”, Environ. Sci. Technol., 51, 14352 (2017).
    7. E. Kim and R. Patel, “Recent advances in covalent triazine framework based separation membranes”, Membr. J., 31, 184 (2021).
    8. E. Kim and R. Patel, “Recent advances in metal organic framework based thin film nanocomposite membrane for nanofiltration”, Membr. J., 31, 35 (2021).
    9. L. Byunghee and P. Rajkumar, “Oil/water separation technology by mxene composite membrane: A review”, Membr. J., 31, 304 (2021).
    10. B. P. Biswal, H. D. Chaudhari, R. Banerjee, U. K. Kharul, “Chemically stable covalent organic framework (COF)-polybenzimidazole hybrid membranes: Enhanced gas separation through pore modulation”, Chem. Eur. J., 22, 4695 (2016).
    11. C. Wang and R. Patel, “Recent advances on ionic liquid based mixed matrix membrane for CO2 separation”, Membr. J., 31, 1 (2021).
    12. H. Fan, M. Peng, I. Strauss, A. Mundstock, H. Meng, and J. Caro, “MOF-in-COF molecular sieving membrane for selective hydrogen separation”, Nat. Commun., 12, 38 (2021).
    13. H. C. Gulbalkan, Z. P. Haslak, C. Altintas, A. Uzun, and S. Keskin, “Assessing CH4/N2 separation potential of MOFs, COFs, IL/MOF, MOF/polymer, and COF/polymer composites”, Chem. Eng. J., 428, 131249 (2022).
    14. H. Jiang, Y. Chen, S. Song, Z. Guo, Z. Zhang, C. Zheng, G. He, H. Wang, H. Wu, T. Huang, Y. Ren, X. Liu, J. Zhang, Y. Yin, Z. Jiang, and M. D. Guiver, “Confined facilitated transport within covalent organic frameworks for propylene/propane membrane separation”, Chem. Eng. J., 439, 135657 (2022).
    15. A. Knebel and J. Caro, “Metal–organic frameworks and covalent organic frameworks as disruptive membrane materials for energy-efficient gas separation”, Nat. Nanotechnol., 17, 911 (2022).
    16. G. O. Aksu, I. Erucar, Z. P. Haslak, S. Keskin, “Accelerating discovery of COFs for CO2 capture and H2 purification using structurally guided computational screening”, Chem. Eng. J., 427, 131574 (2022).
    17. M. Bu, Y. Feng, Q. Li, Y. Wang, S. Feng, K. Zhang, Y. Jiang, L. Fan, Z. Kang, and D. Sun, “A binary all-nanoporous composite membrane constructed: Via vapor phase transformation for highpermeance gas separation”, Inorg. Chem. Front., 8, 5016-5023 (2021).
    18. S. Das, T. Ben, S. Qiu, and V. Valtchev, “Two-dimensional COF-three-dimensional MOF dual-layer membranes with unprecedentedly high H2/CO2 selectivity and ultrahigh gas permeabilities”, ACS Appl. Mater. Interfaces, 12, 52899 (2020).
    19. Y. Yang, K. Goh, P. Weerachanchai, and T. H. Bae, “3D covalent organic framework for morphologically induced high-performance membranes with strong resistance toward physical aging”, J. Membr. Sci., 574, 235 (2019).
    20. A. Chen, H. Guo, J. Zhou, Y. Li, X. He, L. Chen, and Y. Zhang, “Polyacrylonitrile nanofibers coated with covalent organic frameworks for oil/water separation”, ACS Appl. Nano Mat., 5, 3925 (2022).
    21. Q. Liang, B. Jiang, N. Yang, L. Zhang, Y. Sun, and L. Zhang, “Superhydrophilic modification of polyvinylidene fluoride membrane via a highly compatible covalent organic framework-COOH/ dopamine-integrated hierarchical assembly strategy for oil-water separation”, ACS Appl. Mater. Interfaces, 14, 45880 (2022).
    22. Y. Liu, W. Li, C. Yuan, L. Jia, Y. Liu, A. Huang, Y. Cui, “Two-dimensional fluorinated covalent organic frameworks with tunable hydrophobicity for ultrafast oil–water separation”, Angew. Chem. Int. Ed., 61, e202113348 (2022).
    23. L. Chen, C. Zhou, L. Tan, W. Zhou, H. Shen, C. Lu, and L. Dong, “Enhancement of compatibility between covalent organic framework and polyamide membrane via an interfacial bridging method: Toward highly efficient water purification”, J. Membr. Sci., 656, 120590 (2022).
    24. A. R. Corcos, G. A. Levato, Z. Jiang, A. M. Evans, A. G. Livingston, B. J. Mariñas, and W. R. Dichtel, “Reducing the pore size of covalent organic frameworks in thin-film composite membranes enhances solute rejection”, ACS Mater. Lett., 1, 440 (2019).
    25. H. Wang, H. Wang, H. Jiang, A. Sheng, Z. Wei, Y. Li, C. Wu, and H. Li, “Positively charged polysulfonamide nanocomposite membranes incorporating hydrophilic triazine-structured COFs for highly efficient nanofiltration”, ACS Appl. Nano Mater., 3, 9329 (2020).
    26. Y. Zheng, J. Shen, J. Yuan, N. A. Khan, X. You, C. Yang, S. Zhang, A. El-Gendi, H. Wu, R. Zhang, and Z. Jiang, “2D nanosheets seeding layer modulated covalent organic framework membranes for efficient desalination”, Desalination, 532, 115753 (2022).
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