DESALINATION
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2024
·
IF 8.3
Yin-Xin Fang,Yu-Fei Lin,Zhen-Liang Xu,Dibakar Pandaya,Sun-Jie Xu
Thin-film composite (TFC) membranes have been recently applied in the mono/divalent ions separation, which is essential for resource recycle, wastewater treatment, and lithium resource extraction. However, the TFC membranes fabricated between the polyethyleneimine (PEI) and trimesoyl chloride (TMC) usually show a low water permeance. Herein, piperazine (PIP) is added in the PEI aqueous phase solution to fabricate a polyamide (PA) layer for the enhancement of water permeance. Meanwhile, the diffusion rate of PIP to the two-phase interface is reduced by the hydrogen bond effect between PIP and MPDTp COFs interlayer, which can weaken the reaction of PIP and TMC and maintain a high ion rejection. Pure water permeance of the obtained PA-PIP/Fe-COF/PES membrane is 16.1 L m −2 h −1 bar −1 , and the Li + /Mg 2+ separation factor is 73.0, which is almost two times higher than the PA-PIP/PES under Li + /Mg 2+ mass ratio of 1:20. Besides, the membrane also keeps satisfactory performance in Na + /Mg 2+ , Cl − /SO 4 2− , Na + /Ca 2+ separation, and ten days of long-term testing. Therefore, this work raises a new strategy to prepare a high-efficiency mono/divalent ions separation nanofiltration membrane.
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
Molecular Catalysis
·
2024
·
IF 3.9
Qiang Liu,Qiaobo Liao,Chenghua Zhang,Congxin Du,Lei Zhou,Jiao Geng,Kai Xi,Xingbang Hu
Frustrated Lewis Pairs (FLPs) were widely used as metal-free catalysts in current chemistry. More and more researches began to focus on heterogeneous FLPs to meet industrial production needs. Nevertheless, these reported heterogeneous FLPs were mostly constructed based on solid-state Lewis bases (LB) combined with small molecule Lewis acids (LA), such as B(C 6 F 5 ) 3 , which led to incomplete recovery of more expensive LA. In order to construct heterogeneous FLPs with stability and cyclicity based on solid LA, herein, we propose the strategy of first preparing heterogeneous COFs-B(C 6 F 5 ) 2 (solid LA) by reducing part of the C=N bonds on COFs through H-B(C 6 F 5 ) 2 , followed by introducing 1,8-diazabicycloundecano-7-ene (DBU) to construct semi-solid heterogeneous FLPs COFs-B(C 6 F 5 ) 2 /DBU. Simultaneously, these FLPs catalysts showed excellent catalytic performance in the field of terminal alkyne hydrogenation to olefins and could be cycled 8 times without loss of catalytic activity.
研究领域:
催化
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材料科学
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有机化学
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产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2024
·
IF 8.4
Yaqi Zhang,Shiwei Tian,Qiankun Sha,Kangli Ding,Xuhuan Yan,Xingxiang Zhang,Na Han
Covalent organic frameworks (COFs) have evolved into a transformative category of nanofiltration materials due to their intrinsic pore channels and high porosity, sparking a burgeoning interest in fully harnessing the potential of COFs for applications in nanofiltration . Herein, a sandwich structured MXene/COFs membrane was fabricated by the technique of layer-by-layer electrophoretic deposition (LBL EPD), with COFs nanospheres (COFs NPs) serving as the intermediate layer. During the EPD process , controlling the deposition time allows for convenient regulation of each layer's thickness, enabling rapid production of defect-free MXene/COFs membranes. The ultra-thin MXene layer offers excellent film-forming properties for COFs NPs, whereas the intermediate layer of COFs NPs plays a primary sieving function. Moreover, the pore-rich COFs NPs, the ultra-thin MXene layer, and the COFs NPs layer with abundant slits guarantee short and successive mass transport pathways. Under optimal conditions, the MXene/COFs membrane provided a permeance as high as 200.2 L‧m −2 ‧h −1 ‧bar −1 and a rejection rate of Congo red (CR) as high as 98.9 %. This exceptional performance holds steadfast even within pH ranges of 7–11 and during long-term operation. Meanwhile, MXene/COFs membranes exhibit commendable salt/dye separation performance, achieving an excellent separation factor of 121.1 for NaCl/CR. Moreover, the membrane's exceptional robustness and mechanical strength further facilitate its stable utilization under high transmembrane pressure (1–5 bar). To summarize, MXene/COFs membranes, characterized by their excellent nanofiltration and salt/dye separation performance, highlight the advantages of COFs within the nanofiltration field. This study introduces an innovative alternative approach to designing COFs membranes for highly efficient and high-precision molecular separations.
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
SEPARATION AND PURIFICATION TECHNOLOGY
·
2023
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IF 8.6
Xuemei Wang,Zhen Zhang,Jing Ru,Pengfei Huang,Yuan Ma,Jie Zhang,Xinzhen Du,Xiaoquan Lu
In view of the serious carcinogenic, teratogenic and mutagenic properties of polycyclic aromatic hydrocarbons (PAHs), which cause significant harm to human beings and the environment. Therefore, developing rapid adsorption and efficient analytical methods are research topic with practical significance. Herein, an innovative MOFs@COFs-based molecular trap materials were prepared with hierarchical porous core–shell structure and used as solid-phase microextraction (SPME) fiber coating, which combined with high performance liquid chromatography (HPLC) to achieve the efficient separation, capture, and detection for 7 PAHs in real samples. The possible adsorption mechanism was systematically verified and explained. Under the optimized conditions, the method developed in this experiment had a wide linear range (0.005–400 µg·L −1 ) with a good linear correlation coefficient (R 2 > 0.9984), low detection limits (0.002–0.405 µg·L −1 , S/N = 3) and low quantification limits (0.005–1.351 µg·L −1 , S/N = 10). The relative standard deviations of individual fibers and different batches of fibers were 0.26–3.64% and 0.40–5.91%, respectively. Besides, the fiber showed higher enrichment capacity and extraction efficiency for PAHs compared to commercial SPME fibers and other material fibers, and exhibited excellent acid-base stability and reproducibility. This work provided a favorable synthetic pathway for the preparation of MOFs@COFs composites by layer-modified assembly synthesis strategy, showed excellent practical applicability as a SPME fiber coating combined with HPLC, and could be realized to provide technical support for future studies on the separation, adsorption, and analysis of PAHs in the petrochemical industrial zone of the Yellow River Basin.
研究领域:
环境科学
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分析化学
✓ 已验证
产品关联
DOI
高影响因子
Biotechnology for Biofuels
·
2021
·Vol. 14
·期 1
·1-12
·
IF 6.04
Zhou Zi-Wen,Cai Chun-Xian,Xing Xiu,Li Jun,Hu Zu-E.,Xie Zong-Bo,Wang Na,Yu Xiao-Qi
Background Production of biodiesel from renewable sources such as inedible vegetable oils by enzymatic catalysis has been a hotspot but remains a challenge on the efficient use of an enzyme. COFs (Covalent Organic Frameworks) with large surface area and porosity can be applied as ideal support to avoid aggregation of lipase and methanol. However, the naturally low density limits its application. In this work, we reported a facile synthesis of core–shell magnetic COF composite (Fe 3 O 4 @COF-OMe) to immobilize RML ( Rhizomucor miehei lipase), to achieve its utilization in biodiesel production. Result This strategy gives extrinsic magnetic property, and the magnetic COFs is much heavier and could disperse in water medium well, facilitating the attachment with the enzyme. The resultant biocomposite exhibited an excellent capacity of RML due to its high surface area and fast response to the external magnetic field, as well as good chemical stability. The core–shell magnetic COF-OMe structure not only achieved highly efficient immobilization and recovery processes but also maintained the activity of lipase to a great extent. RML@Fe 3 O 4 @COF-OMe performed well in practical applications, while free lipase did not. The biocomposite successfully achieved the production of biodiesel from Jatropha curcas Oil with a yield of about 70% in the optimized conditions. Conclusion Magnetic COFs (Fe 3 O 4 @COF-OMe) for RML immobilization greatly improved catalytic performance in template reaction and biodiesel preparation. The magneticity makes it easily recovered and separated from the system. This first successful attempt of COFs-based immobilized enzyme broadened the prospect of biodiesel production by COFs with some inspiration.
研究领域:
生物化学
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材料科学
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可再生能源
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产品关联
DOI
PubMed
高影响因子
Water
·
2021
·Vol. 13
·期 23
·3338
·
IF 3.103
Yunjie Ma,Xin Gao,Yang Ruan,Hang Cui,Li Zhang,Wei Zhang,Shaoyan Wang
Resin based covalent organic framework material was used as filler for solid phase extraction (SPE), and the solid phase extraction effect was compared with that of traditional COF material (TpBD COFs). The enrichment capacity of four phthalate esters (dimethyl phthalate, diethyl phthalate, dibutyl phthalate, dioctyl phthalate) in beverage samples was investigated by SPE. Adsorption experiments showed that the kinetic adsorption behavior of COF materials for phthalate esters (PAEs) was more consistent with the quasi-second-order kinetic adsorption model, and the static adsorption behavior is more in line with the Freundlich isothermal adsorption model. Solid phase extraction experiments proved that the SPE column prepared with two COF materials as adsorbents had good adsorption effects, high recovery (water: 97.99–100.56% and beverage: 97.93–100.23%) and were reusable (50 cycles), which could meet the requirements for trace detection of phthalate ester. It was found that the solid phase extraction effect was better than the four types of commercial SPE columns. The new COF material reduced the cost of monomer use and provided the possibility for its industrial production. Meanwhile, it also provided a new feasible scheme for enriching trace phthalate esters in practical samples.Keywords:resin-based COFs;phthalate esters;solid phase extraction;trace analysis
研究领域:
分析化学
·
环境科学
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2022
·
IF 9.965
Jiajia Wang,Lizhi Wang,Du Zhang,You Wang,Jiawei Li,Fa Zhou,Jianhan Huang,You-Nian Liu
Herein, the covalently connected core–shell metal–organic frameworks (MOFs)@covalent-organic frameworks (COFs) hybrid materials were successfully constructed by coating the stable COF-OH shell on the NH 2 -MIL-125 core. The introduction of the NH 2 -MIL-125 core endowed the hybrid materials with high Brunauer–Emmett–Teller (BET) surface area ( S BET ) and abundant unsaturated metal sites. And the coating of COF-OH shell endowed the hybrid materials outstanding physicochemical stability and visible-light response, and suitable band gaps. Moreover, the thickness of the COF-OH shell was carefully adjusted according to the feeding amount of NH 2 -MIL-125. Impressively, the electron transfer pathway in the formed heterostructure was clarified and it was proven that a type-II heterojunction was generated between the MOFs and the COFs. The formed stable C N covalent bonds in the interfacial layer was beneficial to the photogenerated electron transfer and the electron-hole pairs separation, which greatly enhanced the CO 2 photocatalytic reduction. The product NH 2 -MIL-125@COF-3 exhibited the highest CO yield of 22.93 μmol·g −1 ·h −1 , about 2 times higher than NH 2 -MIL-125 (11.82 μmol·g −1 ·h −1 ) and 3 times greater than COF-OH (7.26 μmol·g −1 ·h −1 ). This work can provide helpful ideas for the careful design of the novel MOFs@COFs hybrid materials as well as useful exploration for the CO 2 photocatalytic reduction.
研究领域:
材料科学
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环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Nano Materials
·
2020
·
IF 0
Heyun Wang,Hao Wang,Haoji Jiang,Ao Sheng,Zhong Wei,Yingchun Li,Chunlin Wu,Hao Li
Although covalent organic frameworks (COFs) have attracted extensive attention in recent years due to their unique advantages, the use of triazine-structured COFs in the nanofiltration (NF) membrane separation processes for acid wastewater containing heavy metal ions has not been explored. We selected hydrophilic triazine-structured COF nanosheets (NENP-1) that were added to a polysulfonamide (PSA) layer via interfacial polymerization to fabricate nanocomposite membranes (NENP-1-PSA/PES). The NENP-1 brings about the synergy of improved hydrophilicity and positive charge ability with suitable pore sizes that facilitate high permeation for water molecules and high rejection for inorganic salts. Meanwhile, the NENP-1 was covalently linked to PSA matrix with better interface compatibility and membrane stability. The water flux and MgCl2 rejection of the membrane increased up to 15.1 L/m2·h·bar and 93.3%, respectively, after adding only 0.1 w/v% NENP-1, which corresponded to increases of 149.6% and 4.6% compared to the pristine PSA membrane. In addition, the membrane also exhibited good stability in acid condition. This study paves the way for the development of membrane materials with the excellent separation performances in desalination and acidic environments.
研究领域:
材料科学
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环境工程
✓ 已验证
产品关联
DOI
MATERIALS CHEMISTRY AND PHYSICS
·
2022
·
IF 4.778
Meng Xia,Tieyin Shen,Chaokun Li,Ruimei Fan,Lijuan Feng,Qi Chen
In this contribution, we demonstrate the synthesis of hydrazone-linked COF-Paper composites (namely COF-Paper1 and COF-Paper2) constructed from two monomers of benzene-1,3,5-tricarbohydrazide (Bth) and dimethoxyterephthal-aldehyde (Dma) or 2,5-dihydroxyterephthalaldehyde (Dha) via in-situ growth method using filter paper as a matrix. Interestingly, 2D COFs paper composites display excellent luminescence in the solid-state, and the as-synthesized COF-Paper1 and COF-Paper2 can be used as turn-off fluorescence sensors to visually detect Fe 3+ ions and UO 2 2+ ions by the naked eye, respectively. Moreover, the visible limit of detection for Fe 3+ and UO 2 2+ was 5.6 ng cm −2 and 27 ng cm −2 , respectively. XPS and FT-IR results reveal that resulting COF-Papers have significant coordination ability toward target metal ions . This effective coordination induces electron transfer from the electron-rich building module to the electron-deficient metal ion, resulting in the fluorescence quenching process. This work not only provides a methodology to grow and assemble 2D COFs into large size ensembles but also paves a new pathway for visual detection of target metal ions.
研究领域:
材料科学
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分析化学
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2021
·
IF 19.503
Yamei Huang,Peiyao Du,Wen-Xiong Shi,Ye Wang,Shuang Yao,Zhi-Ming Zhang,Tong-Bu Lu,Xiaoquan Lu
Solar-driven CO 2 reduction with H 2 O oxidation into liquid fuels is highly desirable for sustainable carbon cycle to achieve carbon neutral, but represents a great challenge for artificial photosynthesis. Herein, bimetallic PdIn nanoclusters are confined in a photosensitizing covalent organic framework (N 3 -COF) to facilely construct Pd x In y @N 3 -COF composites (x:y = 1:0, 0:1, 1:2, 1:1, 2:1). The resulting PdIn@N 3 -COF exhibits excellent activity for CO 2 photoreduction with H 2 O oxidation as the H + and e − source, showing a record-high total yield of 798 μmol g -1 for producing CH 3 OH (74 %) and CH 3 CH 2 OH (26 %) among the framework materials. The synergy in both the bimetallic nanocluster and cluster@N 3 -COF contributes greatly to C C coupling and interfacial charge transfer, thus achieving excellent activity for conversion of CO 2 to C 1 /C 2 alcohols on the non-copper catalysts. This work highlights the amazing potential for constructing bimetallic nanocluster@photosensitizing supports to produce alcohols in artificial photosynthesis with H 2 O oxidation.
研究领域:
材料科学
·
化学
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环境科学
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能源科学
✓ 已验证
产品关联
DOI
高影响因子
Advanced Composites and Hybrid Materials
·
2022
·Vol. 5
·期 3
·1743-1755
·
IF 11.806
Bi Xue,Di Hang,Liu Jia,Meng Yafang,Song Yuying,Meng Weihua,Qu Hongqiang,Fang Lide,Song Pingan,Xu Jianzhong
Epoxy resin (EP) is a commercially important resin with many important industrial applications but is impeded by its inherent flammability. Ammonium polyphosphate (APP) represents an eco-friendly and effective fire retardant for EP, but its moisture sensitivity and poor interfacial compatibility with EP often give rise to unsatisfactory fire retardance and adverse impacts on mechanical properties of EP. To address these issues, we herein report a core–shell-structured modified APP, APP@COFs, using Schiff base covalent organic frameworks (COFs) as a surface modifier. The results show that the addition of 2 parts per hundreds of resins (phr) APP@COFs effectively enhances the flame retardancy of EP, leading to a self-extinguishing capability and a limiting oxygen index of 27.1%. Compared with virgin EP, the peak heat release rate is decreased by 54.7% due to the modes of action of APP@COFs in both gas and condensed phases. Additionally, because of improved interfacial compatibility, the resulting EP/APP@COFs composites show improved mechanical properties, e.g., a 37% increase in the impact toughness of EP/2 phr APP@COFs relative to that of EP. This work provides an effective method for modifying APP and the development of advanced fire-retardant EP materials for practical applications in industries. Graphical abstract A core–shell-structured fire retardant has been developed for creating fire-retardant epoxy resin composites with improved mechanical properties.
研究领域:
材料科学
·
高分子化学
·
阻燃性
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2023
·
IF 9.5
Song Zhao,Nanxi Di,Ran Lei,Jixiao Wang,Zhi Wang
Covalent organic frameworks (COFs) are attractive innovative crystalline porous materials that have immense potential for the production of high-performance nanofiltration membranes. Although the conventional water-organic interfacial polymerization process has been broadly applied to fabricate COFs composite membranes on polymeric substrates, it cannot be applicable for COFs constructed by poorly water-soluble aromatic amine monomers . Herein, we report the fabrication of triphenylamine-based COFs composite membranes via an oligomer-triggered interfacial polymerization (OT-IP) process on a hydrolyzed polyacrylonitrile (HPAN) substrate, in which the interfacial reaction occurred between an acetic acid aqueous solution and an organic solution of 1,3,5-triformylphloroglucinol (Tp) in n-hexane and tris(4-aminophenyl)amine (TAPA) in mesitylene premixed in a short time. The Tp-TAPA oligomers generated during the premixing were characterized in terms of morphology and molecular weight. The TpTAPA film formation during the OT-IP process was in situ observed through an optical contact angle measurement device. The TpTAPA/HPAN composite membranes displayed a water permeance of 68.1 L⋅m −2 ⋅h −1 ·bar −1 , and the rejections of different dye (EBT, CR) and drug (DG, AG) molecules above 92.0%. In addition, the composite membrane showed excellent stability in acidic solution and continuous filtration for 75 h. The results indicated that the OT-IP approach is a feasible and efficient approach to fabricate triphenylamine-based COF composite membranes with water-insoluble monomers.
研究领域:
材料科学
·
化学工程
·
膜技术
·
纳米技术
✓ 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）