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Menachem Elimelech - One of the best experts on this subject based on the ideXlab platform.
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the significant role of Support Layer solvent annealing in interfacial polymerization the case of epoxide based membranes
Journal of Membrane Science, 2020Co-Authors: Menachem Elimelech, Rhea Verbeke, Marijn Seynaeve, Maarten Bastin, Douglas M Davenport, Samuel Eyley, Wim Thielemans, Guy Koeckelberghs, Ivo F J VankelecomAbstract:Abstract The applicability of state-of-the-art water purification membranes in harsh feed streams is limited due to their insufficient chemical robustness. Epoxide chemistry has been recently introduced to achieve pH- and chlorine-stable nanofiltration (NF). This study further investigated the influence of interfacial polymerization (IP) synthesis parameters on the resulting epoxide-based thin-film composite (TFC) membrane structure and performance. Epoxide polymerization could be initiated by N,N,N′,N′-tetramethyl-1,6-hexanediamine and NaOH. Surprisingly, neither the type of initiator, nor the initiator concentration used during IP, influenced membrane rejection of rose bengal (RB) dye (1017 g mol-1), which was constant at ~ 90%. This consistent RB rejection was primarily determined by annealing of the cross-linked polyimide Support by toluene, which is the solvent used during IP. In contrast, the poly(epoxyether) top-Layer determined membrane selectivity for methyl orange, a smaller dye of 327 g mol-1. The effect of solvent annealing of the membrane Support by diethyl carbonate, dimethyl sulfoxide and m-xylene was also investigated and revealed that the changes induced by solvent contact are physical rather than chemical in nature. This study shows, for the first time, the substantial direct impact of the solvents used during IP to influence Support properties and the resulting membrane performance. Solvent annealing can therefore be considered as a tool in membrane fabrication—during IP or as a post-treatment step—to further tune the separation performance for specific applications.
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thin film composite membrane compaction in high pressure reverse osmosis
Journal of Membrane Science, 2020Co-Authors: Douglas M Davenport, Rhea Verbeke, Ivo F J Vankelecom, Cody L Ritt, Marcel Dickmann, Werner Egger, Menachem ElimelechAbstract:Abstract Membrane deformation under an applied hydraulic pressure, often termed compaction, is observed in almost all pressure-driven membrane processes. Most notably, compaction decreases water permeability in conventional reverse osmosis (RO) and is expected to critically hinder high-pressure reverse osmosis (HPRO) for hypersaline brine desalination. In this work, we demonstrated that compaction decreases the water permeability of commercial RO membranes from 2.0 L m−2 h−1 bar−1 at 70 bar applied hydraulic pressure to 1.3 L m−2 h−1 bar−1 at 150 bar. The morphological effects of compaction were primarily associated with changes in the Support Layer, where a ~60% decrease in cross-sectional thickness is observed following compaction at 150 bar hydraulic pressure. In contrast, positron annihilation lifetime spectroscopy demonstrates that the selective Layer does not compact irreversibly. The mechanism that drives compaction was found to be the difference in hydraulic pressure across the interface of the selective and Support Layers. We further found that compaction can reduce the Support Layer surface porosity by up to ~95%. This decreased porosity is identified as the cause for compaction-induced water permeability decline, while the intrinsic permeability of the selective Layer is not influenced by compaction. As such, we conclude that compaction of the Support Layer has an inextricable impact on composite membrane performance. Finally, we propose recommendations for developing compaction-resistant membranes that can maintain high water permeability, and thus good desalination performance, in high-pressure membrane applications, such as HPRO.
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a path to ultraselectivity Support Layer properties to maximize performance of biomimetic desalination membranes
Environmental Science & Technology, 2018Co-Authors: Jay R Werber, Cassandra J Porter, Menachem ElimelechAbstract:Reverse osmosis (RO) has become a premier technology for desalination and water purification. The need for increased selectivity has incentivized research into novel membranes, such as biomimetic membranes that incorporate the perfectly selective biological water channel aquaporin or synthetic water channels like carbon nanotubes. In this study, we consider the performance of composite biomimetic membranes by projecting water permeability, salt rejection, and neutral-solute retention based on the permeabilities of the individual components, particularly the water channel, the amphiphilic biLayer matrix, and potential Support Layers that include polymeric RO, nanofiltration (NF), and porous ultrafiltration membranes. We find that the Support Layer will be crucial in the overall performance. Selective, relatively low-permeability Supports minimize the negative impact of defects in the biomimetic Layer, which are currently the main performance-limiting factor for biomimetic membranes. In particular, RO membr...
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studying water and solute transport through desalination membranes via neutron radiography
Journal of Membrane Science, 2018Co-Authors: Devin L Shaffer, Jacob M Lamanna, David L. Jacobson, Daniel S Hussey, Menachem Elimelech, Edwin P ChanAbstract:Abstract Neutron radiography, a non-destructive imaging technique, is applied to study water and solute transport through desalination membranes. Specifically, we use neutron radiography to quantify lithium chloride draw solute concentrations across a thin-film composite membrane during forward osmosis permeation. This measurement provides direct visual confirmation of incomplete Support Layer wetting and reveals significant dilutive external concentration polarization of the draw solution outside of the membrane Support Layer. These transport-limiting phenomena have been hypothesized in previous work and are not accounted for in the standard thin-film model of forward osmosis permeation, resulting in inaccurate estimations of membrane transport properties. Our work demonstrates neutron radiography as a powerful measurement tool for studying membrane transport and emphasizes the need for direct experimental measurements to refine the forward osmosis transport model.
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desalination by forward osmosis identifying performance limiting parameters through module scale modeling
Journal of Membrane Science, 2015Co-Authors: Akshay Deshmukh, Menachem ElimelechAbstract:Abstract In this study, we analyze the effects of membrane properties, namely water permeability, solute permeability, and structural parameter, on the overall performance of an FO membrane module to extract water from simulated seawater (0.6 M NaCl). By considering the thermodynamic limit of operation, we demonstrate that the maximum achievable water recovery is practically independent of membrane properties, and higher maximum water recovery is achievable with counter-current compared to co-current mode. Analysis of the module-scale model indicates that reducing the Support Layer structural parameter offers substantial reductions in the membrane area required to achieve a specified water recovery. For example, a 25% reduction of the structural parameter of a state-of-the-art thin-film composite (TFC) membrane (from 400 to 300 μm) yields a sizable 20% reduction in membrane area. In contrast, quintupling the water permeability coefficient (from 2.0 to 10.0 L m−2 h−1 bar−1) of a modern TFC membrane generates only a modest 10% saving in membrane area. In addition, because of the permeability-selectivity trade-off that governs current polymeric membranes, doubling the water permeability coefficient would cause crippling ~7-fold increases in forward and reverse solute permeation. This quantitative study models the potential performance of a module-scale FO desalination process and firmly highlights the need to prioritize the reduction of Support Layer mass transport resistances over water permeability increases in membrane development.
Heechul Choi - One of the best experts on this subject based on the ideXlab platform.
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anti biofouling effect of a thin film nanocomposite membrane with a functionalized carbon nanotube blended polymeric Support for the pressure retarded osmosis process
RSC Advances, 2020Co-Authors: Yeji Kim, Eunmok Yang, Hosik Park, Heechul ChoiAbstract:In this study, the anti-biofouling effect of a thin film nanocomposite (TFN) membrane with a functionalized-carbon-nanotube-blended polymeric Support Layer was analyzed to determine the applicability of this membrane for the pressure-retarded osmosis (PRO) process. The anti-biofouling property of TFN membranes for the PRO process was characterized by SEM, FTIR, and AFM, as well as contact angle measurements and zeta potential analysis of the bottom side of the Support Layer. The anti-biofouling effect of the fabricated membrane for the PRO process was analyzed by bacterial attachment tests on the bottom surface of the Support Layer and biofouling tests in a cross-flow operation system in the PRO mode (AL-DS). The TFN membrane with 0.5 wt% fCNTs exhibited enhanced anti-biofouling properties of the bottom surface of the Support Layer compared to the bare TFC membrane due to the low roughness, high negative surface charge, and hydrophilicity. Compared to the bare TFC membrane, the Support Layer of the fCNT0.5-TFN membrane exhibited a 35% decrease in bacterial attachment. In a laboratory-scale biofouling test, the water flux of the fCNT0.5-TFN membrane was ∼10% less than that of the bare TFC membrane in the PRO mode.
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integrating seawater desalination and wastewater reclamation forward osmosis process using thin film composite mixed matrix membrane with functionalized carbon nanotube blended polyethersulfone Support Layer
Chemosphere, 2017Co-Authors: Hyeongyu Choi, Moon Son, Heechul ChoiAbstract:Abstract Thin-film composite mixed matrix membrane (TFC MMM) with functionalized carbon nanotube (fCNT) blended in polyethersulfone (PES) Support Layer was synthesized via interfacial polymerization and phase inversion. This membrane was firstly tested in lab-scale integrating seawater desalination and wastewater reclamation forward osmosis (FO) process. Water flux of TFC MMM was increased by 72% compared to that of TFC membrane due to enhanced hydrophilicity. Although TFC MMM showed lower water flux than TFC commercial membrane, enhanced reverse salt flux selectivity (RSFS) of TFC MMM was observed compared to TFC membrane (15% higher) and TFC commercial membrane (4% higher), representing membrane permselectivity. Under effluent organic matter (EfOM) fouling test, 16% less normalized flux decline of TFC MMM was observed compared to TFC membrane. There was 8% less decline of TFC MMM compared to TFC commercial membrane due to fCNT effect on repulsive foulant–membrane interaction enhancement, caused by negatively charged membrane surface. After 10 min physical cleaning, TFC MMM displayed higher recovered normalized flux than TFC membrane (6%) and TFC commercial membrane (4%); this was also Supported by visualized characterization of fouling Layer. This study presents application of TFC MMM to integrated seawater desalination and wastewater reclamation FO process for the first time. It can be concluded that EfOM fouling of TFC MMM was suppressed due to repulsive foulant–membrane interaction.
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thin film nanocomposite membrane with cnt positioning in Support Layer for energy harvesting from saline water
Chemical Engineering Journal, 2016Co-Authors: Moon Son, Hosik Park, Lei Liu, Hyeongyu Choi, Joon Ha Kim, Heechul ChoiAbstract:Abstract The pressure retarded osmosis (PRO) process has been considered as an alternative and renewable technology to generate electricity from mixing two solutions of different salinities. However, improving the osmotic performance of semi-permeable membrane is still a major challenge in the PRO system. Therefore, thin-film nanocomposite (TFN) membrane was synthesized by using carbon nanotubes (CNT)-embedded-polyethersulfone (PES) Supporting Layer and polyamide active Layer in this study. The prepared membranes were further employed in the PRO process to harvest energy from saline water. The water flux increase of the TFN membrane was promoted by CNT-induced porosity and the hydrophilicity of the Support Layer as well as by the chemical etching of the active Layer. The water flux and maximum power density of the developed TFN membrane was found to be 87% (averaged from 2 bar to 10 bar) and 110% greater than for bare thin-film composite (TFC) membranes, respectively. Furthermore, the TFN membrane preparation could easily be scaled up using conventional fabrication methods with less than 2% additional material cost. Therefore, this finding could contribute to the commercialization of sustainable energy generation by utilizing the tremendous potential of fresh- and salt-water mixing.
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thin film nanocomposite membrane with cnt positioning in Support Layer for energy harvesting from saline water
Chemical Engineering Journal, 2016Co-Authors: Hosik Park, Hyeongyu Choi, Heechul ChoiAbstract:Abstract The pressure retarded osmosis (PRO) process has been considered as an alternative and renewable technology to generate electricity from mixing two solutions of different salinities. However, improving the osmotic performance of semi-permeable membrane is still a major challenge in the PRO system. Therefore, thin-film nanocomposite (TFN) membrane was synthesized by using carbon nanotubes (CNT)-embedded-polyethersulfone (PES) Supporting Layer and polyamide active Layer in this study. The prepared membranes were further employed in the PRO process to harvest energy from saline water. The water flux increase of the TFN membrane was promoted by CNT-induced porosity and the hydrophilicity of the Support Layer as well as by the chemical etching of the active Layer. The water flux and maximum power density of the developed TFN membrane was found to be 87% (averaged from 2 bar to 10 bar) and 110% greater than for bare thin-film composite (TFC) membranes, respectively. Furthermore, the TFN membrane preparation could easily be scaled up using conventional fabrication methods with less than 2% additional material cost. Therefore, this finding could contribute to the commercialization of sustainable energy generation by utilizing the tremendous potential of fresh- and salt-water mixing.
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efficacy of carbon nanotube positioning in the polyethersulfone Support Layer on the performance of thin film composite membrane for desalination
Chemical Engineering Journal, 2015Co-Authors: Moon Son, Hosik Park, Lei Liu, Hyeongyu Choi, Evrim Celik, Heechul ChoiAbstract:Abstract A thin-film composite (TFC) membrane with a functionalized carbon nanotubes (fCNT) blended Support Layer (fTFC) was successfully synthesized by phase inversion method and interfacial polymerization. fTFC membrane was characterized and compared with TFC bare membrane to investigate the effect of fCNT on membrane performance. The fTFC membrane showed enhanced water permeability due to its increased hydrophilicity, enhanced pore properties of the Support Layer without sacrificing NaCl rejection compared to that of the TFC bare membrane. The fTFC membrane showed a 10–20% enhanced water flux in the seawater reverse osmosis (SWRO) at pressures over 50 bar, and a 90% enhanced water flux in the brackish water reverse osmosis (BWRO) operating pressure at 30–40 bar. Moreover, the fTFC membrane exhibits higher organic fouling resistance compared to the TFC bare membrane due to the 50% higher initial water flux and more negative surface charged surface.
Jeffrey R Mccutcheon - One of the best experts on this subject based on the ideXlab platform.
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proper accounting of mass transfer resistances in forward osmosis improving the accuracy of model predictions of structural parameter
Journal of Membrane Science, 2015Co-Authors: Jason T. Arena, Jeffrey R MccutcheonAbstract:Abstract This work demonstrates a more accurate method for calculating structural parameter ( S ) of asymmetric osmotic membranes using experimental data and a theoretical flux model which encapsulates all significant boundary Layer phenomena. External boundary Layer effects on the porous side of the membrane have been neglected in many current models. In these models, external concentration polarization (ECP) effects get combined with internal concentration polarization (ICP), resulting in inflated S values. In this study, we proposed a mathematical flux model in which ECP effects are accounted for, so that S can be more accurately measured. This model considered the in-series resistances for solute transport based on intrinsic properties of the membrane, as well as boundary Layers at membrane surfaces and within the Support Layer. We therefore introduced new equations to define total resistance to solute transport and reflection coefficient of membranes in FO. The results indicate that ICP is less severe than previously predicted and that cross-flow velocity, temperature and concentration of the draw and the feed solutions impact both external and internal concentration polarization. Our calculations surprisingly show that changes in cross-flow velocity impact internal concentration polarization due to induced mixing within the Support Layer. Also, we suggest that it is critical to consider the “ residence time ” of solutes in the vicinity of the selective Layer when determining the membrane selectivity.
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impact of Support Layer pore size on performance of thin film composite membranes for forward osmosis
Journal of Membrane Science, 2015Co-Authors: Liwei Huang, Jeffrey R MccutcheonAbstract:Abstract Previous investigations of forward osmosis (FO) concluded that thin film composite (TFC) membranes should be designed with hydrophilic Supports to help mitigate internal concentration polarization and improve water flux. A number of research groups and companies around the world have responded to those findings by developing TFC membranes with hydrophilic Supporting materials. However, there has been few fundamental studies on how hydrophilic Support structure affects selective Layer formation and hence membrane performance. Here, a systematic investigation on the influence of Support Layer pore size on the osmotic performance of thin film composite membranes is conducted for the first time. Specifically, TFC membranes were made by interfacial polymerization to form a polyamide selective Layer on top of a series of commercially available nylon 6,6 microfiltration membranes with similar physical and chemical properties but different pore sizes. The interfacial polymerization process is affected by the Support pore dimensions and the resulting polyamide composite membranes exhibited varying film morphology, cross-linking degree, mechanical integrity, and permselectivity. Osmotic flux tests show that the osmotic flux performances (water flux, salt flux and specific salt flux) are dependent on a permeability-selectivity trade-off which is in part impacted by the pore size of the Support Layer.
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influence of membrane Support Layer hydrophobicity on water flux in osmotically driven membrane processes
Journal of Membrane Science, 2008Co-Authors: Jeffrey R Mccutcheon, Menachem ElimelechAbstract:Osmotically driven membrane processes, such as forward osmosis (FO) and pressure-retarded osmosis (PRO), rely on the utilization of large osmotic pressure differentials across semi-permeable membranes to generate water flux. Previous investigations on these two processes have demonstrated how asymmetric membrane structural characteristics, primarily of the Support Layers, impact water flux performance. In this investigation we demonstrate that Support Layer hydrophilicity or wetting plays a crucial role in water flux across asymmetric semi-permeable membranes. The results show that the polyester (PET) non-woven and polysulfone Supports typically present in thin-film composite (TFC) reverse osmosis (RO) membranes do not wet fully when exposed to water, thereby resulting in a marked decrease in water flux. A cellulosic RO membrane exhibited modestly higher water fluxes due to its more hydrophilic Support Layer. Removal of the PET Layers from the cellulosic and TFC RO membranes resulted in an increased water flux for the cellulosic membrane and very little change in flux for the TFC membrane. Pretreatment with hydraulic pressure (RO mode), feed solution degassing, and use of surfactants were used to further elucidate the wetting mechanisms of the different Support Layers within each membrane. The importance of considering membrane Support Layer chemistry in further development of membranes tailored specifically for osmotically driven membrane processes is discussed.
Yong Taek Lee - One of the best experts on this subject based on the ideXlab platform.
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preparation and characterization of pvdf tio2 organic inorganic composite membranes for fouling resistance improvement
Journal of Membrane Science, 2009Co-Authors: Su Jin Oh, Nowon Kim, Yong Taek LeeAbstract:Abstract In this study, a polyvinylidene fluoride (PVDF) ultrafiltration (UF) membrane was modified by dispersing nano-sized titanium(IV) oxide (TiO 2 ) particles in a PVDF solution. PVDF flat-sheet membranes were fabricated by a phase inversion method. Nonwoven fabric and PET film were used as the Support Layer. This study investigates the effect of TiO 2 nanoparticles, type of coagulants, and Support Layers on membrane permeability. The experimental result indicates that the membrane surface can be modified by adding TiO 2 nanoparticles, coagulant solvent compositions, and Support materials. PVDF membrane fouling was reduced by changing the membrane surface from hydrophobic to hydrophilic after TiO 2 addition. PVDF membranes immersed in pure water coagulation bath solution revealed typical large finger-like structures; however, when water/isopropanol mixtures were used as the coagulant solvent, PVDF membranes exhibited sponge-like structures instead of finger-like structures. By using the PET film (instead of nonwoven fabric) as the Support Layer, excessive penetration of the cast solution into the Support Layer could be prevented. However, a dense PET film obstructed the exchange of polymer solution and coagulation bath solution and therefore small pores were formed due to a slow membrane formation process.
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preparation and characterization of pvdf tio2 organic inorganic composite membranes for fouling resistance improvement
Journal of Membrane Science, 2009Co-Authors: Nowon Kim, Yong Taek LeeAbstract:Abstract In this study, a polyvinylidene fluoride (PVDF) ultrafiltration (UF) membrane was modified by dispersing nano-sized titanium(IV) oxide (TiO 2 ) particles in a PVDF solution. PVDF flat-sheet membranes were fabricated by a phase inversion method. Nonwoven fabric and PET film were used as the Support Layer. This study investigates the effect of TiO 2 nanoparticles, type of coagulants, and Support Layers on membrane permeability. The experimental result indicates that the membrane surface can be modified by adding TiO 2 nanoparticles, coagulant solvent compositions, and Support materials. PVDF membrane fouling was reduced by changing the membrane surface from hydrophobic to hydrophilic after TiO 2 addition. PVDF membranes immersed in pure water coagulation bath solution revealed typical large finger-like structures; however, when water/isopropanol mixtures were used as the coagulant solvent, PVDF membranes exhibited sponge-like structures instead of finger-like structures. By using the PET film (instead of nonwoven fabric) as the Support Layer, excessive penetration of the cast solution into the Support Layer could be prevented. However, a dense PET film obstructed the exchange of polymer solution and coagulation bath solution and therefore small pores were formed due to a slow membrane formation process.
Hyeongyu Choi - One of the best experts on this subject based on the ideXlab platform.
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integrating seawater desalination and wastewater reclamation forward osmosis process using thin film composite mixed matrix membrane with functionalized carbon nanotube blended polyethersulfone Support Layer
Chemosphere, 2017Co-Authors: Hyeongyu Choi, Moon Son, Heechul ChoiAbstract:Abstract Thin-film composite mixed matrix membrane (TFC MMM) with functionalized carbon nanotube (fCNT) blended in polyethersulfone (PES) Support Layer was synthesized via interfacial polymerization and phase inversion. This membrane was firstly tested in lab-scale integrating seawater desalination and wastewater reclamation forward osmosis (FO) process. Water flux of TFC MMM was increased by 72% compared to that of TFC membrane due to enhanced hydrophilicity. Although TFC MMM showed lower water flux than TFC commercial membrane, enhanced reverse salt flux selectivity (RSFS) of TFC MMM was observed compared to TFC membrane (15% higher) and TFC commercial membrane (4% higher), representing membrane permselectivity. Under effluent organic matter (EfOM) fouling test, 16% less normalized flux decline of TFC MMM was observed compared to TFC membrane. There was 8% less decline of TFC MMM compared to TFC commercial membrane due to fCNT effect on repulsive foulant–membrane interaction enhancement, caused by negatively charged membrane surface. After 10 min physical cleaning, TFC MMM displayed higher recovered normalized flux than TFC membrane (6%) and TFC commercial membrane (4%); this was also Supported by visualized characterization of fouling Layer. This study presents application of TFC MMM to integrated seawater desalination and wastewater reclamation FO process for the first time. It can be concluded that EfOM fouling of TFC MMM was suppressed due to repulsive foulant–membrane interaction.
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thin film nanocomposite membrane with cnt positioning in Support Layer for energy harvesting from saline water
Chemical Engineering Journal, 2016Co-Authors: Moon Son, Hosik Park, Lei Liu, Hyeongyu Choi, Joon Ha Kim, Heechul ChoiAbstract:Abstract The pressure retarded osmosis (PRO) process has been considered as an alternative and renewable technology to generate electricity from mixing two solutions of different salinities. However, improving the osmotic performance of semi-permeable membrane is still a major challenge in the PRO system. Therefore, thin-film nanocomposite (TFN) membrane was synthesized by using carbon nanotubes (CNT)-embedded-polyethersulfone (PES) Supporting Layer and polyamide active Layer in this study. The prepared membranes were further employed in the PRO process to harvest energy from saline water. The water flux increase of the TFN membrane was promoted by CNT-induced porosity and the hydrophilicity of the Support Layer as well as by the chemical etching of the active Layer. The water flux and maximum power density of the developed TFN membrane was found to be 87% (averaged from 2 bar to 10 bar) and 110% greater than for bare thin-film composite (TFC) membranes, respectively. Furthermore, the TFN membrane preparation could easily be scaled up using conventional fabrication methods with less than 2% additional material cost. Therefore, this finding could contribute to the commercialization of sustainable energy generation by utilizing the tremendous potential of fresh- and salt-water mixing.
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thin film nanocomposite membrane with cnt positioning in Support Layer for energy harvesting from saline water
Chemical Engineering Journal, 2016Co-Authors: Hosik Park, Hyeongyu Choi, Heechul ChoiAbstract:Abstract The pressure retarded osmosis (PRO) process has been considered as an alternative and renewable technology to generate electricity from mixing two solutions of different salinities. However, improving the osmotic performance of semi-permeable membrane is still a major challenge in the PRO system. Therefore, thin-film nanocomposite (TFN) membrane was synthesized by using carbon nanotubes (CNT)-embedded-polyethersulfone (PES) Supporting Layer and polyamide active Layer in this study. The prepared membranes were further employed in the PRO process to harvest energy from saline water. The water flux increase of the TFN membrane was promoted by CNT-induced porosity and the hydrophilicity of the Support Layer as well as by the chemical etching of the active Layer. The water flux and maximum power density of the developed TFN membrane was found to be 87% (averaged from 2 bar to 10 bar) and 110% greater than for bare thin-film composite (TFC) membranes, respectively. Furthermore, the TFN membrane preparation could easily be scaled up using conventional fabrication methods with less than 2% additional material cost. Therefore, this finding could contribute to the commercialization of sustainable energy generation by utilizing the tremendous potential of fresh- and salt-water mixing.
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efficacy of carbon nanotube positioning in the polyethersulfone Support Layer on the performance of thin film composite membrane for desalination
Chemical Engineering Journal, 2015Co-Authors: Moon Son, Hosik Park, Lei Liu, Hyeongyu Choi, Evrim Celik, Heechul ChoiAbstract:Abstract A thin-film composite (TFC) membrane with a functionalized carbon nanotubes (fCNT) blended Support Layer (fTFC) was successfully synthesized by phase inversion method and interfacial polymerization. fTFC membrane was characterized and compared with TFC bare membrane to investigate the effect of fCNT on membrane performance. The fTFC membrane showed enhanced water permeability due to its increased hydrophilicity, enhanced pore properties of the Support Layer without sacrificing NaCl rejection compared to that of the TFC bare membrane. The fTFC membrane showed a 10–20% enhanced water flux in the seawater reverse osmosis (SWRO) at pressures over 50 bar, and a 90% enhanced water flux in the brackish water reverse osmosis (BWRO) operating pressure at 30–40 bar. Moreover, the fTFC membrane exhibits higher organic fouling resistance compared to the TFC bare membrane due to the 50% higher initial water flux and more negative surface charged surface.
