The Experts below are selected from a list of 11397 Experts worldwide ranked by ideXlab platform
Zhen Xu - One of the best experts on this subject based on the ideXlab platform.
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ultrathin graphene Nanofiltration Membrane for water purification
Advanced Functional Materials, 2013Co-Authors: Zhen XuAbstract:A method of fabricating ultrathin (≈22–53 nm thick) graphene Nanofiltration Membranes (uGNMs) on microporous substrates is presented for efficient water purification using chemically converted graphene (CCG). The prepared uGNMs show well packed layer structure formed by CCG sheets, as characterized by scanning electron microscopy, atomic force microscopy, and transmission electron microscopy. The performance of the uGNMs for water treatment was evaluated on a dead end filtration device and the pure water flux of uGNMs was high (21.8 L m−2 h−1 bar−1). The uGNMs show high retention (>99%) for organic dyes and moderate retention (≈20–60%) for ion salts. The rejection mechanism of this kind of negatively charged Membranes is intensively studied, and the results reveal that physical sieving and electrostatic interaction dominate the rejection process. Because of the ultrathin nature of uGNMs, 34 mg of CCG is sufficient for making a square meter of Nanofiltration Membrane, indicating that this new generation graphene-based Nanofiltration technology would be resource saving and cost-effective. The integration of high performance, low cost, and simple solution-based fabrication process promises uGNMs great potential application in practical water purification.
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Ultrathin graphene Nanofiltration Membrane for water purification
Advanced Functional Materials, 2013Co-Authors: Yi Han, Zhen Xu, Chao GaoAbstract:A method of fabricating ultrathin (≈22-53 nm thick) graphene Nanofiltration Membranes (uGNMs) on microporous substrates is presented for efficient water purification using chemically converted graphene (CCG). The prepared uGNMs show well packed layer structure formed by CCG sheets, as characterized by scanning electron microscopy, atomic force microscopy, and transmission electron microscopy. The performance of the uGNMs for water treatment was evaluated on a dead end filtration device and the pure water flux of uGNMs was high (21.8 L m -2 h -1 bar -1 ). The uGNMs show high retention ( > 99%) for organic dyes and moderate retention (≈20-60%) for ion salts. The rejection mechanism of this kind of negatively charged Membranes is intensively studied, and the results reveal that physical sieving and electrostatic interaction dominate the rejection process. Because of the ultrathin nature of uGNMs, 34 mg of CCG is sufficient for making a square meter of Nanofiltration Membrane, indicating that this new generation graphene-based Nanofiltration technology would be resource saving and cost-effective. The integration of high performance, low cost, and simple solution-based fabrication process promises uGNMs great potential application in practical water purification. Ultrathin graphene Nanofiltration Membranes (uGNMs) are fabricated on microporous substrates. These graphene Membranes (no more than 53-nm thick) are thin enough to have excellent flexibility and can be bent without any breakage. The uGNMs show high pure water flux and high retention for organic dyes. The dark red Direct Red 81 solution turns into colorless after filtration. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Chao Gao - One of the best experts on this subject based on the ideXlab platform.
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Ultrathin graphene Nanofiltration Membrane for water purification
Advanced Functional Materials, 2013Co-Authors: Yi Han, Zhen Xu, Chao GaoAbstract:A method of fabricating ultrathin (≈22-53 nm thick) graphene Nanofiltration Membranes (uGNMs) on microporous substrates is presented for efficient water purification using chemically converted graphene (CCG). The prepared uGNMs show well packed layer structure formed by CCG sheets, as characterized by scanning electron microscopy, atomic force microscopy, and transmission electron microscopy. The performance of the uGNMs for water treatment was evaluated on a dead end filtration device and the pure water flux of uGNMs was high (21.8 L m -2 h -1 bar -1 ). The uGNMs show high retention ( > 99%) for organic dyes and moderate retention (≈20-60%) for ion salts. The rejection mechanism of this kind of negatively charged Membranes is intensively studied, and the results reveal that physical sieving and electrostatic interaction dominate the rejection process. Because of the ultrathin nature of uGNMs, 34 mg of CCG is sufficient for making a square meter of Nanofiltration Membrane, indicating that this new generation graphene-based Nanofiltration technology would be resource saving and cost-effective. The integration of high performance, low cost, and simple solution-based fabrication process promises uGNMs great potential application in practical water purification. Ultrathin graphene Nanofiltration Membranes (uGNMs) are fabricated on microporous substrates. These graphene Membranes (no more than 53-nm thick) are thin enough to have excellent flexibility and can be bent without any breakage. The uGNMs show high pure water flux and high retention for organic dyes. The dark red Direct Red 81 solution turns into colorless after filtration. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
A R Hassan - One of the best experts on this subject based on the ideXlab platform.
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Effect of shear rate on the performance of Nanofiltration Membrane for water desalination
2020Co-Authors: A.f. Ismail, A R Hassan, Be Cheer NgAbstract:Asymmetric Nanofiltration Membranes were fabricated from a ternary dope composition consisting of cellulose acetate (CA), formamide and acetone using a simple drylwet phase inversion process. In order to fabricate a high performance Nanofiltration Membrane, the effects of rheological factor of dope solutions, that is shear rate on the performance of nanof~tration Membranes for water desalination has been studied. The Membranes performances that are based on percentage of rejection of sodium chloride (NaCl) and fluxes with different concentrations of sodium chloride are reported. Generally, the percentage of rejection and fluxes were found to increase with increasing of shear rate until a critical level of shear rate is achieved. The experimental results showed that the fluxes were increased and percentage of rejection is decreased With sodium chloride concentrations. An optimum percentage of rejection and fluxes obtained were about 56.76 % and 7.44 x lo4 ds, respectively. The optimum shear rate was found to be at 304 s'l. It was also found that Membranes with shear rate below 152s" are not suitable to be used as a Nanofiltration Membrane due to their low mechanical strength.
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formation and characterization of asymmetric Nanofiltration Membrane effect of shear rate and polymer concentration
Journal of Membrane Science, 2006Co-Authors: A.f. Ismail, A R HassanAbstract:Abstract In this study, we report the effects of shear rates and polymer concentrations in the formation of asymmetric Nanofiltration Membrane using a simple dry/wet phase inversion technique. Employing the combination of irreversible thermodynamic model, solution-diffusion model (Spiegler–Kedem equation), steric-hindrance pore (SHP) model and Teorell–Meyers (TMS) model, the transport mechanisms and Membrane structural properties were determined and have been characterized for different cases of those formation parameters. The experimental and modeling showed very promising results in terms of Membrane performance with interesting structural details. The optimum shear rate (critical shear rate) was found to be at about 203.20 s −1 and the best polymer concentration toward the formation of high performance Nanofiltration Membrane is in the range of 19.60–23.10%. The modeling results suggested that the pore radius of the Membranes produced lies within the range of pore radius of 29 commercial available Membranes. This study also proposed that the electrolytes transport through Nanofiltration Membrane was dominated by a convection factor which accounted approximately 30% more than a diffusion factor. This study also indicated that shear rate and polymer concentration were found to affect the Membrane performance and structural properties by providing, to a certain extent, an oriented Membrane skin layer which in turn exhibiting an improvement in Membrane separation ability.
Yi Han - One of the best experts on this subject based on the ideXlab platform.
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Ultrathin graphene Nanofiltration Membrane for water purification
Advanced Functional Materials, 2013Co-Authors: Yi Han, Zhen Xu, Chao GaoAbstract:A method of fabricating ultrathin (≈22-53 nm thick) graphene Nanofiltration Membranes (uGNMs) on microporous substrates is presented for efficient water purification using chemically converted graphene (CCG). The prepared uGNMs show well packed layer structure formed by CCG sheets, as characterized by scanning electron microscopy, atomic force microscopy, and transmission electron microscopy. The performance of the uGNMs for water treatment was evaluated on a dead end filtration device and the pure water flux of uGNMs was high (21.8 L m -2 h -1 bar -1 ). The uGNMs show high retention ( > 99%) for organic dyes and moderate retention (≈20-60%) for ion salts. The rejection mechanism of this kind of negatively charged Membranes is intensively studied, and the results reveal that physical sieving and electrostatic interaction dominate the rejection process. Because of the ultrathin nature of uGNMs, 34 mg of CCG is sufficient for making a square meter of Nanofiltration Membrane, indicating that this new generation graphene-based Nanofiltration technology would be resource saving and cost-effective. The integration of high performance, low cost, and simple solution-based fabrication process promises uGNMs great potential application in practical water purification. Ultrathin graphene Nanofiltration Membranes (uGNMs) are fabricated on microporous substrates. These graphene Membranes (no more than 53-nm thick) are thin enough to have excellent flexibility and can be bent without any breakage. The uGNMs show high pure water flux and high retention for organic dyes. The dark red Direct Red 81 solution turns into colorless after filtration. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Jiaojiao Zhao - One of the best experts on this subject based on the ideXlab platform.
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Surface fluorination of polyamide Nanofiltration Membrane for enhanced antifouling property
Journal of Membrane Science, 2014Co-Authors: Yafei Li, Runnan Zhang, Yanlei Su, Xueting Zhao, Jiaojiao Zhao, Zhongyi JiangAbstract:Abstract A new kind of fluorinated polyamine was successfully synthesized and grafted onto the polyamide Membrane surface to fabricate an antifouling Nanofiltration Membrane with low surface free energy. The surface composition of the fluorinated polyamide Nanofiltration Membrane was confirmed by Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The Membrane cross-section morphology was observed by a field emission scanning electron microscopy (FESEM). The presence of perfluoroalkyl groups on the Membrane surface significantly lowered the surface free energy from 60.0 to 44.4 mJ/m 2 . The filtration experiment results indicated that the surface fluorination did not lower the separation performance of the polyamide Nanofiltration Membrane significantly. The antifouling experiment results demonstrated that the fluorinated polyamide Nanofiltration Membranes exhibited superior antifouling property, that is, high flux recovery ratio (~98.5%) and low total flux decline ratio (~11%) during protein aqueous solution and humic acid aqueous solution filtration.
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separation performance of thin film composite Nanofiltration Membrane through interfacial polymerization using different amine monomers
Desalination, 2014Co-Authors: Yafei Li, Runnan Zhang, Yanlei Su, Xueting Zhao, Zhongyi Jiang, Yanan Dong, Jiaojiao ZhaoAbstract:Abstract Four kinds of thin-film composite (TFC) Membranes were prepared via interfacial polymerization using diethylenetriamine (DETA), triethylenetetramine (TETA), tetraethylenepentamine (TEPA) and piperazidine (PIP) as water-soluble monomer, and trimesoyl chloride (TMC) as organic-soluble monomer. The surface chemical features of the resultant Membranes were confirmed by contact angle measurement and Fourier transform infrared spectroscopy (FTIR). The Membrane morphology and surface charges were investigated through Scanning electronic microscopy (SEM) and Zeta potential, respectively. Salt rejection was used to evaluate the separation performance of the four kinds of TFC Membranes. The results showed that all the four kinds of TFC Membranes exhibited typical negatively charged Nanofiltration Membrane characteristics. The salt rejections followed the sequence: Na2SO4 > MgSO4 > MgCl2 and the rejection of Na2SO4 was all over 80%. It was also found that the solubility of water-soluble monomer in organic solvent played an important role in manipulating the Membrane structure, charge properties and thus the separation performance.
