ChemNanoMat
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2019
·Vol. 5
·期 9
·1244-1250
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IF 3.431
Yuxiu Sun,Hongliang Huang,Xiangyu Guo,Zhihua Qiao,Chongli Zhong
Graphical Counter diffusion has been used to drive the in situ formation of mixed metal MOF membranes in a confined space with nanostructure arrays under hydrothermal conditions. Through this approach, a variety of mixed metal ZIF membranes can be synthesized on different kinds of porous substrates. The development of facile, versatile strategies for the fabrication of mixed component metal-organic framework (MOF) membranes is highly desired, but still very challenging due to the difficulty in controlling crystal growth rates of every single component in a specific confined space. It is difficult to adjust the formation of multicomponent MOF membrane in a controlled manner using conventional approaches such as secondary growth methods. Herein, we present a facile strategy that prepares the mixed metal zeolitic imidazolate framework (ZIF) membranes in situ in a confined space with nanostructure arrays under hydrothermal conditions using the counter diffusion mechanism. The counter diffusion of different metal ions from both the homogeneous bulk solution and the solid metal oxide nanostructure grown on substrate leads to the specific effective reaction zone by encountering with linker molecules at the interface. Subsequently, nucleation and crystal growth generate the continuous mixed metal MOF membranes. With this approach, a variety of mixed metal ZIF membranes were synthesized on different kinds of substrates. The prepared membranes exhibited good sieving effect to H 2 and heavier gas molecules during both single and mixed gas permeation tests. This work opens a fresh avenue for the synthesis of mixed component MOF membranes, and the counter diffusion effect can be intentionally adopted to the design and fabrication of selective mixed metal MOF membrane on various supports.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2022
·
IF 9.136
Chengcheng Wang,Hao Sun,Naixin Wang,Quan-Fu An
Zeolitic imidazolate framework (ZIF) membranes have great potential applications in nanofiltration. However, preparing continuous and intact ZIF membranes on the surface of a substrate remains challenging. In this study, we assembled ZIF-8 nanoparticles in situ in the pores of a porous alumina substrate via a freezing-assisted counter-diffusion method. Although a continuous ZIF-8 membrane was not formed on the surface of the substrate, the obtained nano-confined composite membrane was dense enough to separate antibiotics and salt. The rejection rate of tetracycline was above 99 %, while that of sodium chloride was below 20 %, demonstrating good antibiotic desalination performance. The permeance of the ZIF-8 membrane reached 23.5 LMH/bar. Due to the nano-confined structure, the obtained ZIF-8 composite membrane was robust. Besides, polishing the surface layer did not reduce the separation performance. Moreover, sulfurizing the ZIF-8 membrane improved its stability in water. It also improved the permeance to 31.3 LMH/bar, which remained stable for 100 h. Therefore, the obtained robust ZIF-8 membrane and its derivative composite membrane fabricated via freezing-assisted counter-diffusion have great potential in antibiotic desalination.
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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产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
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2022
·
IF 10.383
Jinyin Lv,Yanwen Cui,Jianhua Yang,Liangqing Li,Xuerong Zhou,Jinming Lu,Gaohong He
Fluorinated metal–organic framework materials (NbOFFIVE-1-Ni, also referred to as KAUST-7) have attracted widespread attention because of their high chemical stability and thermal stability, outstanding tolerance with water and H2S, and high CO2-adsorption selectivity over H2 and CH4. KAUST-7 was expected to be a new membrane material candidate for H2/CO2 separation because of the hindered permeation of CO2 resulting from the interaction between CO2 and (NbOF5)2– of the KAUST-7 framework. A highly H2 perm-selective KAUST-7 membrane was first achieved using a novel strategy of inorganic pillar center-facilitated counterdiffusion (IPCFCD) proposed by us. The IPCFCD method not only effectively avoided the corrosion of hydrofluoric acid to α-Al2O3 tubes in the process of preparing KAUST-7 membranes, but also better reduced grain boundary defects because of the faster nucleation rate and resultant high crystallinity. The KAUST-7 membrane exhibited a high H2/CO2 separation factor (SF) of 27.30 for the 1:1 H2/CO2 binary gas mixture with a high H2 permeance of 5.30 × 10–7 mol m–2 s–1 Pa–1 under ambient conditions and a slight decrease of the H2/CO2 SF with increasing operation temperature and presence of steam. This study highlighted the importance of pre-synthesizing inorganic pillar centers (NiNbOF5 intermediate) and the innovation of a membrane formation process for synthesizing polycrystalline KAUST-7 membranes. Most important of all, our study provided a novel approach to overcome the challenge in fabricating metal–organic framework membranes containing corrosive reactants for the corresponding supports.
研究领域:
材料科学
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化学工程
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产品关联
DOI
PubMed
高影响因子
BIORESOURCE TECHNOLOGY
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2024
·
IF 9.7
Tianyi Wang,Xiaohang Han,Yufei Cheng,Jiaxuan Yang,Langming Bai,Weichen Zeng,Hesong Wang,Nuo Cheng,Han Zhang,Guibai Li,Heng Liang
In this study, electron transport pathways were activated and diversified by coupling counter-diffusion biofilms with micro-electrolysis for Alizarin yellow R (AYR) denitrogenation. Due to the binding of AYR to two residues of EC 4.1.3.36 with higher binding energy, the expression of EC 4.1.3.36 was down-regulated, causing the EC 3.1.2.28 and EC 2.5.1.74 for menaquinone synthesis (redox mediator) undetectable in Membrane aerated biofilm reactors (MABR). Spontaneous electron generation in the micro electrolysis-coupled MABR (ME-MABR) significantly activated two enzymes. Activated menaquinone up-regulated decolourisation related genes expression in ME-MABR, including azoR (2.12 log 2 ), NQO1 (2.97 log 2 ), wrbA (0.45 log 2 ), and ndh (0.47 log 2 ). The diversified electron flow pathways also promoted the nitrogen metabolism coding genes up-regulation, accelerating further inorganic nitrogen denitrogenation after AYR mineralisation. Compared to MABR, the decolourisation, mineralisation, and denitrogenation in ME-MABR increased by 25.80 %, 16.53 %, and 13.32 %, respectively. This study provides new insights into micro-electrolysis enhanced removal of AYR.
研究领域:
环境科学
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微生物学
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生物化学
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DOI
PubMed
高影响因子
Small
·
2024
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IF 13
Xue Hu,Zhiying Li,Jianbo Li,Chuanlong Jin,Junjiang Bao,Xiaopeng Zhang,Xiaobin Jiang,Ning Zhang,Gaohong He
Membrane technology exhibits low cost and high efficiency in gas separation. Zeolite-imidazole framework-67 (ZIF-67) membrane shows a theoretically superior performance in H 2 /CO 2 separation, owing to its effective size-sieving pores between H 2 and CO 2 . However, the gas molecules are permeate through a series of consecutive crystal cells of common ZIF-67 polycrystalline membranes, resulting in high transport resistance to the gas permselective transport. To this end, this work employs a contra-diffusion synthesis to construct a honeycomb ZIF-67 (h-ZIF67) crystalline membrane for low-resistance H 2 /CO 2 permselective transport. The controlled growth of h-ZIF67 following the van der Drift theory produces the honeycomb polycrystal with hierarchical channels for low-resistance gas permeation. The prepared membrane with micron-scale thickness still achieves a H 2 permeance as high as 1.6 × 10 −7 mol m −2 s −1 Pa −1 and a H 2 /CO 2 selectivity of 17, which can be maintained after a long-term operation for the H 2 /CO 2 mixture separation.
研究领域:
材料科学
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化学工程
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气体分离技术
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产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
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2016
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IF 7.145
Yong Du,Wen-Ze Qiu,Yan Lv,Jian Wu,Zhi-Kang Xu
Nanofiltration membranes (NFMs) are widely used in saline water desalination, wastewater treatment, and chemical product purification. However, conventional NFMs suffer from broad pore size distribution, which limits their applications for fine separation, especially in complete separation of molecules with slight differences in molecular size. Herein, defect-free composite NFMs with narrow pore size distribution are fabricated using a contra-diffusion method, with dopamine/polyethylenimine solution on the skin side and ammonium persulfate solution on the other side of the ultrafiltration substrate. Persulfate ions can diffuse through the ultrafiltration substrate into the other side and in situ trigger dopamine to form a codeposited coating with polyethylenimine. The codeposition is hindered on those sites completely covered by the polydopamine/polyethylenimine coating, although it is promoted at the defects or highly permeable regions because it is induced by the diffused persulfate ions. Such a “self-completion” process results in NFMs with highly uniform structures and narrow pore size distribution, as determined by their rejection of neutral solutes. These near electrically neutral NFMs show a high rejection of divalent ions with a low rejection of monovalent ions (MgCl2 rejection = 96%, NaCl rejection = 23%), majorly based on a steric hindrance effect. The as-prepared NFMs can be applied in molecular separation such as isolating cellulose hydrogenation products.
研究领域:
材料科学
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化学工程
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环境工程
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水处理
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）