Removal of Radioactive Pollutants by Liquid Emulsion Membrane From Liquid Waste

International Nuclear Information System (INIS)

Yossef, Y.A.A.

2013-01-01

Radioactive liquid waste should be safely managed because it is potentially hazardous to human health and the environment. Several methods were used for treatment of liquid waste, such as liquid emulsion membrane (LEM). In this work, liquid emulsion membrane using Tri-butyl phosphate (TBP) plus Bis (2-ethylhexyl) phosphate (HDEHP) as mobile carriers, hydrochloric acid (HCl) as stripping agents and an emulsifying agent (span 80) was used for the extraction of uranium ions from radioactive liquid waste. Various parameters influencing the permeation of uranium ions through the membrane have been optimized to separate uranium ions from radioactive liquid waste such as: the effects of membrane material, carrier concentration, operating conditions, etc. were examined; moreover, the transport mechanism of this uranium was also studied. The internal mass transfer in the water/oil (W/O) emulsion drop, the external mass transfer around the drop, the rates of formation, and the decomposition of the complex at the external aqueous-organic interface were considered. The results show that, the liquid emulsion membrane which consists of (25% by volume HDEHP, 0.005 M + 75% by volume TBP, 0.01 M) as extractant (carrier), span 80, 4% (v/v) (sorbitan monooleate) as surfactant agent, hydrochloric acid (HCl), (1.0 M) as stripping agent. From the results, the maximum extraction percent of uranium ions (nearly about of 100%) occurred at the operating conditions: stirring speed =500 rpm, the ratio between LEM and feed phase (liquid waste) = 20 ml: 100 ml, the ratio between organic phase (membrane phase) to internal aqueous phase (stripping phase) = 1.0 and the ph value of the external aqueous phase equal to 5.0.

Ionizable polyethers as specific metal ion carriers in liquid-liquid extraction and liquid membrane separations

International Nuclear Information System (INIS)

Walkowiak, W.; Charewicz, W.A.; Bartsch, R.A.; Ndip, G.M.

1988-01-01

Consideration is given to results of investigations into competitive extraction and penetration through a liquid membrane of alkali and alkaline earth cations from aqueous solutions by a series of lipophilic and ionizable acyclic polyethers of various molecular structure. It is shown that specificity and selectiviy of cation carriers in liquid-liquid extraction and liquid membrane separation depend on molecular structure of acyclic polyethers

Hybrid Nano composite Membranes for PEMFC Applications

International Nuclear Information System (INIS)

Niepceron, F.

2008-03-01

This work aims at validating a new concept of hybrid materials for the realization of proton exchange membranes, an essential constituent of PEM fuel cells. The originality of this nano-composite hybrid concept corresponds to a separation of the membrane's properties. We investigated the preparation of composite materials based on an inert, relatively low cost, polymer matrix (PVDF-HFP) providing the mechanical stability embedding inorganic fillers providing the necessary properties o f proton-conduction and water retention. The first step of this work consisted in the modification of fumed silica to obtain a proton-conducting filler. An ionic exchange capacity (CEI) equal to 3 meq/g was obtained by the original grafting of sodium poly(styrene-sulfonate) chains from the surface of particles. Nano-composite hybrid membranes PVDF-HFP/functionalized silica were accomplished by a film casting process. The coupling of the morphological and physicochemical analyses validated the percolation of the inorganic phase for 30 wt.% of particles. Beyond 40 % of loading, measured protonic conductivity is higher than the reference membrane Nafion 112. Finally, these membranes presented high performances, above 0.8 W/cm 2 , in single-cell fuel cell tests. A compromise is necessary according to the rate of loading between performances in fuel cell and mechanical properties of the membrane. 50 % appeared as best choice with, until 90 C, a remarkable thermal stability of the performances. (author)

Carbon Dioxide Separation with Supported Ionic Liquid Membranes

Energy Technology Data Exchange (ETDEWEB)

Luebke, D.R.; Ilconich, J.B.; Myers, C.R.; Pennline, H.W.

2007-04-01

Supported liquid membranes are a class of materials that allow the researcher to utilize the wealth of knowledge available on liquid properties as a direct guide in the development of a capture technology. These membranes also have the advantage of liquid phase diffusivities higher than those observed in polymeric membranes which grant proportionally greater permeabilities. The primary shortcoming of the supported liquid membranes demonstrated in past research has been the lack of stability caused by volatilization of the transport liquid. Ionic liquids, which possess high carbon dioxide solubility relative to light gases such as hydrogen, are an excellent candidate for this type of membrane since they have negligible vapor pressure and are not susceptible to evaporation. A study has been conducted evaluating the use of several ionic liquids, including 1-hexyl-3-methyl-imidazolium bis(trifuoromethylsulfonyl)imide, 1-butyl-3-methyl-imidazolium nitrate, and 1-ethyl-3-methyl-imidazolium sulfate in supported ionic liquid membranes for the capture of carbon dioxide from streams containing hydrogen. In a joint project, researchers at the University of Notre Dame lent expertise in ionic liquid synthesis and characterization, and researchers at the National Energy Technology Laboratory incorporated candidate ionic liquids into supports and evaluated the resulting materials for membrane performance. Initial results have been very promising with carbon dioxide permeabilities as high as 950 barrers and significant improvements in carbon dioxide/hydrogen selectivity over conventional polymers at 37C and at elevated temperatures. Results include a comparison of the performance of several ionic liquids and a number of supports as well as a discussion of innovative fabrication techniques currently under development.

Metal–organic frameworks based membranes for liquid separation

KAUST Repository

Li, Xin

2017-11-07

Metal-organic frameworks (MOFs) represent a fascinating class of solid crystalline materials which can be self-assembled in a straightforward manner by the coordination of metal ions or clusters with organic ligands. Owing to their intrinsic porous characteristics, unique chemical versatility and abundant functionalities, MOFs have received substantial attention for diverse industrial applications, including membrane separation. Exciting research activities ranging from fabrication strategies to separation applications of MOF-based membranes have appeared. Inspired by the marvelous achievements of MOF-based membranes in gas separations, liquid separations are also being explored for the purpose of constructing continuous MOFs membranes or MOF-based mixed matrix membranes. Although these are in an emerging stage of vigorous development, most efforts are directed towards improving the liquid separation efficiency with well-designed MOF-based membranes. Therefore, as an increasing trend in membrane separation, the field of MOF-based membranes for liquid separation is highlighted in this review. The criteria for judicious selection of MOFs in fabricating MOF-based membranes are given. Special attention is paid to rational design strategies for MOF-based membranes, along with the latest application progress in the area of liquid separations, such as pervaporation, water treatment, and organic solvent nanofiltration. Moreover, some attractive dual-function applications of MOF-based membranes in the removal of micropollutants, degradation, and antibacterial activity are also reviewed. Finally, we define the remaining challenges and future opportunities in this field. This Tutorial Review provides an overview and outlook for MOF-based membranes for liquid separations. Further development of MOF-based membranes for liquid separation must consider the demands of strict separation standards and environmental safety for industrial application.

Metal-organic frameworks based membranes for liquid separation.

Science.gov (United States)

Li, Xin; Liu, Yuxin; Wang, Jing; Gascon, Jorge; Li, Jiansheng; Van der Bruggen, Bart

2017-11-27

Metal-organic frameworks (MOFs) represent a fascinating class of solid crystalline materials which can be self-assembled in a straightforward manner by the coordination of metal ions or clusters with organic ligands. Owing to their intrinsic porous characteristics, unique chemical versatility and abundant functionalities, MOFs have received substantial attention for diverse industrial applications, including membrane separation. Exciting research activities ranging from fabrication strategies to separation applications of MOF-based membranes have appeared. Inspired by the marvelous achievements of MOF-based membranes in gas separations, liquid separations are also being explored for the purpose of constructing continuous MOFs membranes or MOF-based mixed matrix membranes. Although these are in an emerging stage of vigorous development, most efforts are directed towards improving the liquid separation efficiency with well-designed MOF-based membranes. Therefore, as an increasing trend in membrane separation, the field of MOF-based membranes for liquid separation is highlighted in this review. The criteria for judicious selection of MOFs in fabricating MOF-based membranes are given. Special attention is paid to rational design strategies for MOF-based membranes, along with the latest application progress in the area of liquid separations, such as pervaporation, water treatment, and organic solvent nanofiltration. Moreover, some attractive dual-function applications of MOF-based membranes in the removal of micropollutants, degradation, and antibacterial activity are also reviewed. Finally, we define the remaining challenges and future opportunities in this field. This Tutorial Review provides an overview and outlook for MOF-based membranes for liquid separations. Further development of MOF-based membranes for liquid separation must consider the demands of strict separation standards and environmental safety for industrial application.

Experimental performance of indirect air–liquid membrane contactors for liquid desiccant cooling systems

International Nuclear Information System (INIS)

Das, Rajat Subhra; Jain, Sanjeev

2013-01-01

Owing to the stringent indoor air quality (IAQ) requirements and high cost of desiccants, one of the major concerns in liquid desiccant technology has been the carryover, which can be eliminated through indirect contact between desiccant and air. Membrane contactors using microporous semipermeable hydrophobic membranes have a great potential in this regard. This communication investigates the performance of semipermeable membrane based indirect contactors as dehumidifiers in liquid desiccant cooling applications. Experiments on different types of membrane contactors are carried out using lithium chloride (LiCl) solution as desiccant. The membrane contactors consist of alternate channels of air and liquid desiccant flowing in cross-flow direction. Hydrophobic membranes form a liquid tight, vapor permeable porous barrier between hygroscopic solution and moist air, thus eliminating carryover of desiccant droplets. In order to provide maximum contact area for air–desiccant interaction, a wicking material is sandwiched between two membranes in the liquid channel. It is observed that vapor flux upto 1300 g/m 2 h can be achieved in a membrane contactor with polypropylene (PP) membranes, although the dehumidification effectiveness remains low. The effect of key parameters on the transmembrane vapor transport is presented in the paper. - Highlights: • Indirect membrane contactors developed to avoid carryover in liquid desiccant system. • Dehumidification effectiveness and vapor flux reported under varying conditions. • Vapor flux upto 1295 g/m 2 h in polypropylene contactor with high area density. • Dehumidification effectiveness with LiCl solution varies within 23% to 45%

Vacuum membrane distillation of liquid desiccants Utilizing Hollow Fiber Membranes

KAUST Repository

Lefers, Ryan

2018-01-31

This paper documents the testing of a vacuum membrane distillation system intended for use with liquid desiccants. Liquid desiccants offer the possibility for low-energy, ambient temperature dehumidification. Effective desalination and purification of diluted desiccants outputs two important products: a concentrated desiccant for reuse in dehumidification and fresh water. In this study, vacuum membrane distillation was used in the laboratory to purify diluted liquid desiccants. Calcium chloride and magnesium chloride were the desiccants selected for testing. Desiccant solutions were pumped through the lumens of poly(vinylidene fluoride) (PVDF) hollow fiber membranes at varying feed inlet temperatures, solution velocity rates and vacuum set points during membrane distillation. An average flux of 8 kg m-2 h-1 was obtained using 30 wt% magnesium chloride solution at a temperature of 50 °C while applying vacuum to achieve 25 mbar absolute pressure on the air side of the membrane. The results are promising for the development of a full-scale vacuum membrane distillation process for desiccant solution regeneration and fresh water recovery. In addition, the recovered condensate was of sufficient quality for use in agricultural irrigation or drinking water.

Vacuum membrane distillation of liquid desiccants Utilizing Hollow Fiber Membranes

KAUST Repository

Lefers, Ryan; Srivatsa Bettahalli, N.M.; Fedoroff, Nina V.; Nunes, Suzana Pereira; Leiknes, TorOve

2018-01-01

This paper documents the testing of a vacuum membrane distillation system intended for use with liquid desiccants. Liquid desiccants offer the possibility for low-energy, ambient temperature dehumidification. Effective desalination and purification of diluted desiccants outputs two important products: a concentrated desiccant for reuse in dehumidification and fresh water. In this study, vacuum membrane distillation was used in the laboratory to purify diluted liquid desiccants. Calcium chloride and magnesium chloride were the desiccants selected for testing. Desiccant solutions were pumped through the lumens of poly(vinylidene fluoride) (PVDF) hollow fiber membranes at varying feed inlet temperatures, solution velocity rates and vacuum set points during membrane distillation. An average flux of 8 kg m-2 h-1 was obtained using 30 wt% magnesium chloride solution at a temperature of 50 °C while applying vacuum to achieve 25 mbar absolute pressure on the air side of the membrane. The results are promising for the development of a full-scale vacuum membrane distillation process for desiccant solution regeneration and fresh water recovery. In addition, the recovered condensate was of sufficient quality for use in agricultural irrigation or drinking water.

Hyper-cross-linked, hybrid membranes via interfacial polymerization

NARCIS (Netherlands)

Raaijmakers, Michiel

2015-01-01

Hyper-cross-linked, hybrid membranes consist of covalent networks of alternating organic and inorganic, or biological groups. This thesis reports on the preparation of such hybrid networks via interfacial polymerization. The structure-property relationships of the hybrid networks depend strongly on

Structure of hybrid organic-inorganic sols for the preparation of hydrothermally stable membranes

Energy Technology Data Exchange (ETDEWEB)

Castricum, H.L.; Sah, A; Blank, D.H.A.; Ten Elshof, J.E. [Inorganic Materials Science, MESA Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede (Netherlands); Geenevasen, J.A.J. [Van ' t Hoff Institute for Molecular Sciences, University of Amsterdam, Nieuwe Achtergracht 166, 1018 WV Amsterdam (Netherlands); Kreiter, R.; Vente, J.F. [ECN Energy Efficiency in the Industry, Petten (Netherlands)

2008-06-15

A procedure for the preparation of hybrid sols for the synthesis of organic-inorganic microporous materials and thin film membranes is reported. We describe silane reactivity and sol structure for acid-catalysed colloidal sols from mixtures of either tetraethylorthosilicate (TEOS) and methyltriethoxysilane (MTES), or bis(triethoxysilyl)ethane (BTESE) and MTES. Early-stage hydrolysis and condensation rates of the individual silane precursors were followed with 29Si liquid NMR and structural characteristics of more developed sols were studied with Dynamic Light Scattering. Condensation was found to proceed at more or less similar rates for the different precursors. Homogeneously mixed hybrid colloids can therefore be formed from precursor mixtures. The conditions of preparation under which clear sols with low viscosity could be formed from BTESE/MTES were determined. These sols were synthesised at moderate water/silane and acid/silane ratios and could be applied for the coating of defect-free microporous membranes for molecular separations under hydrothermal conditions.

Hybrid membranes of polyamide applied in treatment of waste water

International Nuclear Information System (INIS)

Medeiros, Keila Machado de; Araujo, Edcleide Maria; Lira, Helio de Lucena; Lima, Diego de Farias; Lima, Carlos Antonio Pereira de

2017-01-01

In this work, it was prepared hybrid membranes of polyamide6 (PA6) with montmorillonite (MMT) and porogenic agent (CaCl 2 ). The hybrid membranes with CaCl 2 were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), porosimetry by mercury intrusion (PMI), flux measurements and rejection. By means of X-ray diffraction, it was revealed that the hybrid membranes with CaCl 2 have an exfoliated and/or partially exfoliated structure. For FTIR and DSC of hybrid membranes with CaCl 2 , it was found that the spectra and the crystalline melting temperature remained virtually unchanged compared to PA6 membrane. From the SEM images, it was observed that the addition of the MMT and the CaCl 2 in the membrane of PA6 caused an increase in the amount of pores the surface and cross section of these membranes. By PMI, it was observed that the presence of MMT and CaCl 2 in the membrane caused an increase in the average diameters of pores. The water-oil separation tests, indicated a significant reduction of oil in the permeate, allowing treatment of wastewater contaminated with oil. (author)

Hybrid membranes of polyamide applied in treatment of waste water

Energy Technology Data Exchange (ETDEWEB)

Medeiros, Keila Machado de; Araujo, Edcleide Maria; Lira, Helio de Lucena, E-mail: keilamachadodemedeiros@gmail.com [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Departamento de Engenharia de Materiais; Lima, Diego de Farias; Lima, Carlos Antonio Pereira de [Universidade Estadual da Paraiba (UEPB), Campina Grande, PB (Brazil). Departamento de Engenharia Sanitaria e Ambiental

2017-03-15

In this work, it was prepared hybrid membranes of polyamide6 (PA6) with montmorillonite (MMT) and porogenic agent (CaCl{sub 2} ). The hybrid membranes with CaCl{sub 2} were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), porosimetry by mercury intrusion (PMI), flux measurements and rejection. By means of X-ray diffraction, it was revealed that the hybrid membranes with CaCl{sub 2} have an exfoliated and/or partially exfoliated structure. For FTIR and DSC of hybrid membranes with CaCl{sub 2} , it was found that the spectra and the crystalline melting temperature remained virtually unchanged compared to PA6 membrane. From the SEM images, it was observed that the addition of the MMT and the CaCl{sub 2} in the membrane of PA6 caused an increase in the amount of pores the surface and cross section of these membranes. By PMI, it was observed that the presence of MMT and CaCl{sub 2} in the membrane caused an increase in the average diameters of pores. The water-oil separation tests, indicated a significant reduction of oil in the permeate, allowing treatment of wastewater contaminated with oil. (author)

Uranium Extraction From Artificial Liquid Waste Using Continuous Extraction Liquid membrane Technique

International Nuclear Information System (INIS)

Rusdianasari; Buchari

2002-01-01

The continuous extraction of uranium from artificial liquid waste by emulsion liquid membrane was carried out using one stage mixer-settler. This emulsion liquid membrane containing di-2-ethylhexylphosphoric acid (D2EHPA) and tri-n-buthyl phosphate (TBP) as carrier were carried out using one stage mixer-settler. The optimum condition gave the ratio of emulsion velocity to the feed velocity 1:4 and steady state reached after five minutes. The optimum condition was obtained at the 90.91 % of uranium recovered from raffinate, using EDTA as the masking agent with concentration 5x10 - 2 M . The total concentration of carrier was 3% with ratio D2EHPA and TBP 3:1. The emulsion liquid membrane has high relative selectivity after steady state with separation factors were α U , N i= 115,43 and α U , Fe 328,55. The result of experiment showed that emulsion liquid membrane containing D2EHPA and TBP as carrier have good performance for continuous system

Composite hollow fiber gas-liquid membrane contactors for olefin/paraffin separation

NARCIS (Netherlands)

Nijmeijer, Dorothea C.; Visser, Tymen; Assen, R.; Wessling, Matthias

2004-01-01

Gas¿liquid membrane contactors frequently suffer from undesired wetting of the microporous membrane by the absorption liquid. Stabilization layers at the liquid-side of the microporous membrane potentially prevent this wetting. We apply such stabilized membranes in a membrane contactor using AgNO3

Hybrid capacitive deionization with anion-exchange membranes for lithium extraction

OpenAIRE

Siekierka Anna; Bryjak Marek

2017-01-01

Lithium is considered to be a critical material for various industrial fields. We present our studies on extraction lithium from diluted aqueous solution by novel hybrid system based on a membrane capacitive deionization and batteries desalination. Hybrid CDI is comprised by a lithium selective adsorbent, activated carbon electrode and anion-exchange membranes. Here, we demonstrated implication of various type of anion-exchange membranes and influence their properties on effective capacity an...

Hybrid GaN LED with capillary-bonded II–VI MQW color-converting membrane for visible light communications

International Nuclear Information System (INIS)

Santos, Joao M M; Jones, Brynmor E; Schlosser, Peter J; Herrnsdorf, Johannes; Guilhabert, Benoit; McKendry, Jonathan J D; Hastie, Jennifer E; Laurand, Nicolas; Dawson, Martin D; Watson, Scott; Kelly, Anthony E; De Jesus, Joel; Garcia, Thor A; Tamargo, Maria C

2015-01-01

The rapid emergence of gallium-nitride (GaN) light-emitting diodes (LEDs) for solid-state lighting has created a timely opportunity for optical communications using visible light. One important challenge to address this opportunity is to extend the wavelength coverage of GaN LEDs without compromising their modulation properties. Here, a hybrid source for emission at 540 nm consisting of a 450 nm GaN micro-sized LED (micro-LED) with a micron-thick ZnCdSe/ZnCdMgSe multi-quantum-well color-converting membrane is reported. The membrane is liquid-capillary-bonded directly onto the sapphire window of the micro-LED for full hybridization. At an injection current of 100 mA, the color-converted power was found to be 37 μW. At this same current, the −3 dB optical modulation bandwidth of the bare GaN and hybrid micro-LEDs were 79 and 51 MHz, respectively. The intrinsic bandwidth of the color-converting membrane was found to be power-density independent over the range of the micro-LED operation at 145 MHz, which corresponds to a mean carrier lifetime of 1.9 ns. (paper)

Organosilica Membrane with Ionic Liquid Properties for Separation of Toluene/H₂ Mixture.

Science.gov (United States)

Hirota, Yuichiro; Maeda, Yohei; Yamamoto, Yusuke; Miyamoto, Manabu; Nishiyama, Norikazu

2017-08-03

In this study, we present a new concept in chemically stabilized ionic liquid membranes: an ionic liquid organosilica (ILOS) membrane, which is an organosilica membrane with ionic liquid-like properties. A silylated ionic liquid was used as a precursor for synthesis. The permselectivity, permeation mechanism, and stability of the membrane in the H₂/toluene binary system were then compared with a supported ionic liquid membrane. The membrane showed a superior separation factor of toluene/H₂ (>17,000) in a binary mixture system based on a solution-diffusion mechanism with improved durability over the supported ionic liquid membrane.

Hybrid ion-exchange membranes for fuel cells and separation processes

Energy Technology Data Exchange (ETDEWEB)

Fernandez-Carretero, F.J.; Compan, V. [Departamento de Termodinamica Aplicada, ETSII, Universidad Politecnica de Valencia, 46020 Valencia (Spain); Riande, E. [Instituto de Ciencia y Tecnologia de Polimeros (CSIC), 28006 Madrid (Spain)

2007-11-08

This work reports the preparation and characterization of hybrid membranes cast from dispersions of inorganic fillers in sulfonated polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene solutions. Silica gel, SBA-15 and sepiolite, all of them functionalized with phenylsulfonic acid groups, were used as fillers. For comparative purposes, the performance of composite membranes cast from dispersions of functionalized inorganic fillers in Nafion {sup registered} solutions was investigated. Inspection of the texture of the membranes by using SEM techniques shows that the fillers are better dispersed in sulfonated polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene than in Nafion {sup registered}. The value of the water uptake for the membranes prepared from the former polyelectrolyte is in most cases at least three times that measured for hybrid Nafion {sup registered} membranes. The conductivity of the membranes was measured at 80 C by impedance spectroscopy obtaining values of 3.44, 6.90 and 3.54 S m{sup -1} for the hybrid membranes based on the triblock copolymer containing functionalized silica gel, SBA-15 and sepiolite fillers, respectively. These results compare very favourably with those obtained at 80 C for Nafion {sup registered} hybrid membranes containing silica gel, SBA-15 and sepiolite, all of them fuctionalized with phenylsulfonic acid groups, whose conductivities are, 2.84, 6.75 and 3.31 S m{sup -1}, respectively. Resistance measurements carried out under controlled humidity conditions show that the conductivity of sulfonated triblock copolymer membranes containing functionalized SBA-15 filler undergoes a rather sharp increase when they are conditioned under an atmosphere of 75%, or larger, relative humidity. (author)

Organic-inorganic hybrid membranes in separation processes: a 10-year review

Directory of Open Access Journals (Sweden)

V. C. Souza

2013-12-01

Full Text Available In relation to some inorganic membranes, polymeric membranes have relatively low separation performance. However, the processing flexibility and low cost of polymers still make them highly attractive for many industrial separation applications. Polymer-inorganic hybrid membranes constitute an emerging research field and have been recently developed to improve the separation properties of polymer membranes because they possess properties of both organic and inorganic membranes such as good hydrophilicity, selectivity, permeability, mechanical strength, and thermal and chemical stability. The structures and processing of polymer-inorganic nanocomposite hybrid membranes, as well as their use in the fields of ultrafiltration, nanofiltration, pervaporation, gas separation and separation mechanism are reviewed.

Fabrication of Greener Membranes from Ionic Liquid Solutions

KAUST Repository

Kim, DooLi

2017-06-01

Membrane technology plays a crucial role in different separation processes such as biotechnology, pharmaceutical, and food industries, drinking water supply, and wastewater treatment. However, there is a growing concern that solvents commonly used for membrane fabrication, such as dimethylformamide (DMF), dimethylacetamide (DMAc), and 1-methyl-2-pyrrolidone (NMP), are toxic to the environment and human health. To explore the possibility of substituting these toxic solvents by less toxic or safer solvents, polymers commonly used for membrane fabrication, such as polyacrylonitrile (PAN), cellulose acetate (CA), polyethersulfone (PES), and poly(ether imide sulfone) (EXTEMTM), were dissolved in ionic liquids. Flat sheet and hollow fiber membranes were then fabricated. The thermodynamics of the polymer solutions, the kinetics of phase inversion and other factors, which resulted in significant differences in the membrane structure, compared to those of membranes fabricated from more toxic solvents, were investigated. Higher water permeance with smaller pores, unique and uniform morphologies, and narrower pore size distribution, were observed in the ionic liquid-based membranes. Furthermore, comparable performance on separation of peptides and proteins with various molecular weights was achieved with the membranes fabricated from ionic liquid solutions. In summary, we propose less hazardous polymer solutions to the environment, which can be used for the membrane fabrication with better performance and more regular morphology.

Emulsion Liquid Membrane Technology in Organic Acid Purification

International Nuclear Information System (INIS)

Norela Jusoh; Norasikin Othman; Nur Alina Nasruddin

2016-01-01

Emulsion Liquid Membrane (ELM) process have shown a great potential in wide application of industrial separations such as in removal of many chemicals, organic compounds, metal ions, pollutants and biomolecules. This system promote many advantages including simple operation, high selectivity, low energy requirement, and single stage extraction and stripping process. One potential application of ELM is in the purification of succinic acid from fermentation broth. This study outline steps for developing emulsion liquid membrane process in purification of succinic acid. The steps include liquid membrane formulation, ELM stability and ELM extraction of succinic acid. Several carrier, diluent and stripping agent was screened to find appropriate membrane formulation. After that, ELM stability was investigated to enhance the recovery of succinic acid. Finally, the performance of ELM was evaluated in the extraction process. Results show that formulated liquid membrane using Amberlite LA2 as carrier, palm oil as diluent and sodium carbonate, Na_2CO_3 as stripping agent provide good performance in purification. On the other hand, the prepared emulsion was observed to be stable up to 1 hour and sufficient for extraction process. In conclusion, ELM has high potential to purify succinic acid from fermentation broth. (author)

Polymer-inorganic hybrid proton conductive membranes: Effect of the interfacial transfer pathways

International Nuclear Information System (INIS)

Chen, Pingping; Hao, Lie; Wu, Wenjia; Li, Yifan; Wang, Jingtao

2016-01-01

Highlights: • A series of hybrid membranes are prepared using fillers with different structures. • The fillers (0-D, 1-D, and 2-D) are sulfonated to ensure close surface component. • The effect of filler’s structure on microstructure of hydrid membrane is explored. • For single-kind filler series, 2-D filler has the strongest conduction promotion. • The synergy effect of different kinds of fillers is systematacially investigated. - Abstract: For hybrid membrane, the polymer-inorganic interface along filler surface can be facilely created to be distinctive and controllable pathway for mass transfer. Herein, three kinds of fillers are used as inorganic additives including zero-dimensional silica (0-D, SiO_2), one-dimensional halloysite nanotube (1-D, HNT), and two-dimensional graphene oxide (2-D, GO), which are functionalized by sulfonated polymer layer to ensure close surface component. Then the fillers are incorporated into two types of polymer matrixes (phase-separated sulfonated poly(ether ether ketone) and non-phase-separated chitosan) to prepare three series of hybrid membranes with single-kind filler, double-kinds fillers, or triple-kinds fillers, respectively. The microstructures, physicochemical properties, and proton conduction properties (under hydrated and anhydrous conditions) of the membranes are extensively investigated. It is found that (i) for the single-kind filler-filled membranes, 2-D filler has the strongest promotion ability for proton conductivity of membrane due to the constructed wide and long-range pathways for proton transfer; (ii) while for the hybrid membranes with double-kinds fillers, instead of synergistic promotion effect, the fillers cause more tortuous transfer pathways within membranes and then decrease proton conductivity; (iii) the hybrid membranes with triple-kinds fillers exhibit similar behavior but a little higher conductivity than the membranes with double-kinds fillers.

The liquid membrane for extraction of Yttrium and Dysprosium from Acid Nitric

International Nuclear Information System (INIS)

Johny, W.S.; Raldi-Artono-Koestoer; Kris-Tri-Basuki; Sudibyo

1996-01-01

The determination of surfactant in liquid membrane has been done. The surfactant is span-80 (sorbitol-monooleate), the liquid membrane phase was the organic phase (O), the internal liquid phase (W) with ratio O/W = 1, and surfactant. The organic phase using D 2 EHPA in the kerosene and the internal liquid phase using aqua des or acid nitric. The determination of surfactant with variation of span-80 (0,25 - 2%) in the liquid membrane volume. The speed of stirrer was 3500 rpm in 20 minute. The ratio of liquid membrane phase form and external phase (aqua des or acid nitric) was 1, the speed of stirrer was 350 rpm in 10 minute (permeation process). The liquid phase and the liquid membrane phase was separated and then determinated the volume of liquid membrane, the result of percentage of span-80 was 0,25 % volume. The extraction of yttrium and dysprosium in 2 M HNO 3 was Kd y = 2.945 and Kd D y = 0.019

Ionic liquid-nanoparticle hybrid electrolytes

KAUST Repository

Lu, Yingying; Moganty, Surya S.; Schaefer, Jennifer L.; Archer, Lynden A.

2012-01-01

We investigate physical and electrochemical properties of a family of organic-inorganic hybrid electrolytes based on the ionic liquid 1-methyl-3-propylimidazolium bis(trifluoromethanesulfone) imide covalently tethered to silica nanoparticles (SiO 2

Hybrid capacitive deionization with anion-exchange membranes for lithium extraction

Directory of Open Access Journals (Sweden)

Siekierka Anna

2017-01-01

Full Text Available Lithium is considered to be a critical material for various industrial fields. We present our studies on extraction lithium from diluted aqueous solution by novel hybrid system based on a membrane capacitive deionization and batteries desalination. Hybrid CDI is comprised by a lithium selective adsorbent, activated carbon electrode and anion-exchange membranes. Here, we demonstrated implication of various type of anion-exchange membranes and influence their properties on effective capacity and energy requirements in charge/discharge steps. We described a configuration with anion-exchange membrane characterized by adsorption capacity of 35 mg/g of Li+ with 0.08Wh/g and removal efficiency of 60 % of lithium ions, using novel selective desalination technique.

Hybrid capacitive deionization with anion-exchange membranes for lithium extraction

Science.gov (United States)

Siekierka, Anna; Bryjak, Marek

2017-11-01

Lithium is considered to be a critical material for various industrial fields. We present our studies on extraction lithium from diluted aqueous solution by novel hybrid system based on a membrane capacitive deionization and batteries desalination. Hybrid CDI is comprised by a lithium selective adsorbent, activated carbon electrode and anion-exchange membranes. Here, we demonstrated implication of various type of anion-exchange membranes and influence their properties on effective capacity and energy requirements in charge/discharge steps. We described a configuration with anion-exchange membrane characterized by adsorption capacity of 35 mg/g of Li+ with 0.08Wh/g and removal efficiency of 60 % of lithium ions, using novel selective desalination technique.

Flame Retardancy Effects of Graphene Nanoplatelet/Carbon Nanotube Hybrid Membranes on Carbon Fiber Reinforced Epoxy Composites

Directory of Open Access Journals (Sweden)

Dongxian Zhuo

2013-01-01

Full Text Available Carbon nanotube/graphene nanoplatelet (MWCNT/GNP hybrid membranes with lower liquid permeability and better barrier effect compared to MWCNT membranes were successfully synthesized by vacuum filtering. Their morphologies, water permeability, and pore structures were characterized by a scanning electron microscope (SEM and nitrogen adsorption isotherms. Furthermore, MWCNT/GNP membranes were used to improve the flame retardancy of carbon fiber reinforced polymer (CFRP composites, and the influence of weight percentage of GNPs on the permeability and flame retardancy of MWCNT/GNP membranes was systematically investigated. Results show that incorporation of MWCNT/GNP membranes on CFRP composite plates can remarkably improve the flame retardancy of CFRP composites. Specifically, the incorporation of hierarchical MWCNT/GNP membrane with 7.5 wt% of GNP displays a 35% reduction in the peak heat release rate (PHRR for a CFRP composite plate with the epoxy as matrix and a 11% reduction in PHRR compared with the incorporation of MWCNT membrane only. A synergistic flame retarding mechanism is suggested to be attributed to these results, which includes controlling the pore size and penetrative network structure.

Primary metals extraction by liquid membranes

International Nuclear Information System (INIS)

Subramanian, K.N.

1980-01-01

The extraction of copper and uranium by liquid membranes is presented. The recovery of uranium from wet process phosphoric acid is described. The development of this process has progressed through three stages, firstly the chemistry of uranium extraction as it pertains to liquid membrane systems. This was followed by continuous extraction tests on fresh black acid and on aged acid. Results on a 1 litre/minute pilot plant demonstrated that the process could be operated with a minimum of feed pretreatment and about 90% of uranium could be extracted. The extraction of copper from copper leach liquors is also described. (U.K.)

Application of membrane technologies for liquid radioactive waste processing

International Nuclear Information System (INIS)

2004-01-01

Membrane separation processes have made impressive progress since the first synthesis of membranes almost 40 years ago. This progress was driven by strong technological needs and commercial expectations. As a result the range of successful applications of membranes and membrane processes is continuously broadening. In addition, increasing application of membrane processes and technologies lies in the increasing variations of the nature and characteristics of commercial membranes and membrane apparatus. The objective of the report is to review the information on application of membrane technologies in the processing of liquid radioactive waste. The report covers the various types of membranes, equipment design, range of applications, operational experience and the performance characteristics of different membrane processes. The report aims to provide Member States with basic information on the applicability and limitations of membrane separation technologies for processing liquid radioactive waste streams

The Comparative Study on Vapor-Polymerization and Pressure-dependent Conductance Behavior in Polypyrrole-hybridized Membranes

Energy Technology Data Exchange (ETDEWEB)

Hanif, Zahid; Lee, Seyeong; Arsalani, Nasir; Geckeler, Kurt E.; Hong, Sukwon; Yoon, Myung-Han [Gwangju Institute of Science and Technology, Gwangju (Korea, Republic of)

2016-02-15

In this study, commercially available cellulose membranes were hybridized with conjugated polymer via vapor-phase polymerization using pyrrole and iron chloride as a monomer and oxidant, respectively. The iron (III) chloride layer dip-coated on the hydrophilic cell ulose surface oxidized the vaporized pyrrole monomer leading to the polypyrrole-cellulose hybrid membrane. The conductivity of hybrid membrane was optimized by varying the oxidant concentration and the monomer vapor exposure time. The various surface characterizations of polypyrrole-cellulose hybrid membrane show that the conductive polypyrrole layer was uniformly deposited onto the surface of cellulose fibrous networks unlike the polypyrrole-nylonhybrid membrane prepared in the similar way. The polypyrrole-incorporated cellulose networks exhibits steeper electrical conductance increase over the vertical pressure than its nylon counterpart. Our result suggests that the polypyrrole-cellulose hybrid membrane can be applicable for a disposable high-load pressure sensor.

The Comparative Study on Vapor-Polymerization and Pressure-dependent Conductance Behavior in Polypyrrole-hybridized Membranes

International Nuclear Information System (INIS)

Hanif, Zahid; Lee, Seyeong; Arsalani, Nasir; Geckeler, Kurt E.; Hong, Sukwon; Yoon, Myung-Han

2016-01-01

In this study, commercially available cellulose membranes were hybridized with conjugated polymer via vapor-phase polymerization using pyrrole and iron chloride as a monomer and oxidant, respectively. The iron (III) chloride layer dip-coated on the hydrophilic cell ulose surface oxidized the vaporized pyrrole monomer leading to the polypyrrole-cellulose hybrid membrane. The conductivity of hybrid membrane was optimized by varying the oxidant concentration and the monomer vapor exposure time. The various surface characterizations of polypyrrole-cellulose hybrid membrane show that the conductive polypyrrole layer was uniformly deposited onto the surface of cellulose fibrous networks unlike the polypyrrole-nylonhybrid membrane prepared in the similar way. The polypyrrole-incorporated cellulose networks exhibits steeper electrical conductance increase over the vertical pressure than its nylon counterpart. Our result suggests that the polypyrrole-cellulose hybrid membrane can be applicable for a disposable high-load pressure sensor.

Arsenic Removal by Liquid Membranes

Directory of Open Access Journals (Sweden)

Tiziana Marino

2015-03-01

Full Text Available Water contamination with harmful arsenic compounds represents one of the most serious calamities of the last two centuries. Natural occurrence of the toxic metal has been revealed recently for 21 countries worldwide; the risk of arsenic intoxication is particularly high in Bangladesh and India but recently also Europe is facing similar problem. Liquid membranes (LMs look like a promising alternative to the existing removal processes, showing numerous advantages in terms of energy consumption, efficiency, selectivity, and operational costs. The development of different LM configurations has been a matter of investigation by several researching groups, especially for the removal of As(III and As(V from aqueous solutions. Most of these LM systems are based on the use of phosphine oxides as carriers, when the metal removal is from sulfuric acid media. Particularly promising for water treatment is the hollow fiber supported liquid membrane (HFSLM configuration, which offers high selectivity, easy transport of the targeted metal ions, large surface area, and non-stop flow process. The choice of organic extractant(s plays an essential role in the efficiency of the arsenic removal. Emulsion liquid membrane (ELM systems have not been extensively investigated so far, although encouraging results have started to appear in the literature. For such LM configuration, the most relevant step toward efficiency is the choice of the surfactant type and its concentration.

Supported liquid inorganic membranes for nuclear waste separation

Science.gov (United States)

Bhave, Ramesh R; DeBusk, Melanie M; DelCul, Guillermo D; Delmau, Laetitia H; Narula, Chaitanya K

2015-04-07

A system and method for the extraction of americium from radioactive waste solutions. The method includes the transfer of highly oxidized americium from an acidic aqueous feed solution through an immobilized liquid membrane to an organic receiving solvent, for example tributyl phosphate. The immobilized liquid membrane includes porous support and separating layers loaded with tributyl phosphate. The extracted solution is subsequently stripped of americium and recycled at the immobilized liquid membrane as neat tributyl phosphate for the continuous extraction of americium. The sequestered americium can be used as a nuclear fuel, a nuclear fuel component or a radiation source, and the remaining constituent elements in the aqueous feed solution can be stored in glassified waste forms substantially free of americium.

Hybrid Membrane System for Industrial Water Reuse

Energy Technology Data Exchange (ETDEWEB)

None

2016-08-01

This factsheet describes a project that developed and demonstrated a new hybrid system for industrial wastewater treatment that synergistically combines a forward osmosis system with a membrane distillation technology and is powered by waste heat.

Cellulose multilayer Membranes manufacture with Ionic liquid

KAUST Repository

Livazovic, Sara

2015-05-09

Membrane processes are considered energy-efficient for water desalination and treatment. However most membranes are based on polymers prepared from fossil petrochemical sources. The development of multilayer membranes for nanofiltration and ultrafiltration, with thin selective layers of naturally available cellulose has been hampered by the availability of non-aggressive solvents. We propose the manufacture of cellulose membranes based on two approaches: (i) silylation, coating from solutions in tetrahydrofuran, followed by solvent evaporation and cellulose regeneration by acid treatment; (ii) casting from solution in 1-ethyl-3-methylimidazolum acetate ([C2mim]OAc), an ionic liquid, followed by phase inversion in water. By these methods porous supports could be easily coated with semi-crystalline cellulose. The membranes were hydrophilic with contact angles as low as 22.0°, molecular weight cut-off as low as 3000 g mol-1 with corresponding water permeance of 13.8 Lm−2 h−1 bar−1. Self-standing cellulose membranes were also manufactured without porous substrate, using only ionic liquid as green solvent. This membrane was insoluble in water, tetrahydrofuran, hexane, N,N-dimethylformamide, 1-methyl-2-pyrrolidinone and N,N-dimethylacetamide.

Metal–organic frameworks based membranes for liquid separation

KAUST Repository

Li, Xin; Liu, Yuxin; Wang, Jing; Gascon, Jorge; Li, Jiansheng; Van der Bruggen, Bart

2017-01-01

, the field of MOF-based membranes for liquid separation is highlighted in this review. The criteria for judicious selection of MOFs in fabricating MOF-based membranes are given. Special attention is paid to rational design strategies for MOF-based membranes

Composite materials with ionic conductivity: from inorganic composites to hybrid membranes

Energy Technology Data Exchange (ETDEWEB)

Yaroslavtsev, Andrei B [N.S. Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences, Moscow (Russian Federation)

2009-11-30

Information on composite materials with ionic conductivity including inorganic composites and hybrid polymeric ion exchange membranes containing inorganic or polymeric nanoparticles is generalized. The nature of the effect of increase in the ionic conductivity in this type of materials and the key approaches used for theoretical estimation of the conductivity are considered. Data on the ionic conductivity and some other important properties of composites and membrane materials are presented. Prospects for utilization of composite materials and hybrid membranes in hydrogen power engineering are briefly outlined.

Membrane Treatment of Liquid Salt Bearing Radioactive Wastes

International Nuclear Information System (INIS)

Dmitriev, S. A.; Adamovich, D. V.; Demkin, V. I.; Timofeev, E. M.

2003-01-01

The main fields of introduction and application of membrane methods for preliminary treatment and processing salt liquid radioactive waste (SLRW) can be nuclear power stations (NPP) and enterprises on atomic submarines (AS) utilization. Unlike the earlier developed technology for the liquid salt bearing radioactive waste decontamination and concentrating this report presents the new enhanced membrane technology for the liquid salt bearing radioactive waste processing based on the state-of-the-art membrane unit design, namely, the filtering units equipped with the metal-ceramic membranes of ''TruMem'' brand, as well as the electrodialysis and electroosmosis concentrators. Application of the above mentioned units in conjunction with the pulse pole changer will allow the marked increase of the radioactive waste concentrating factor and the significant reduction of the waste volume intended for conversion into monolith and disposal. Besides, the application of the electrodialysis units loaded with an ion exchange material at the end polishing stage of the radioactive waste decontamination process will allow the reagent-free radioactive waste treatment that meets the standards set for the release of the decontaminated liquid radioactive waste effluents into the natural reservoirs of fish-farming value

Deashing of coal liquids with ceramic membrane microfiltration and diafiltration

Energy Technology Data Exchange (ETDEWEB)

Bishop, B.; Goldsmith, R. [CeraMem Corp., Waltham, MA (United States)

1995-12-31

Removal of mineral matter from liquid hydrocarbons derived from the direct liquefaction of coal is required for product acceptability. Current methods include critical solvent deashing (Rose{sup {reg_sign}} process from Kerr-McGee) and filtration (U.S. Filter leaf filter as used by British Coal). These methods produce ash reject streams containing up to 15% of the liquid hydrocarbon product. Consequently, CeraMem proposed the use of low cost, ceramic crossflow membranes for the filtration of coal liquids bottoms to remove mineral matter and subsequent diafiltration (analogous to cake washing in dead-ended filtration) for the removal of coal liquid from the solids stream. The use of these ceramic crossflow membranes overcomes the limitations of traditional polymeric crossflow membranes by having the ability to operate at elevated temperature and to withstand prolonged exposure to hydrocarbon and solvent media. In addition, CeraMem`s membrane filters are significantly less expensive than competitive ceramic membranes due to their unique construction. With these ceramic membrane filters, it may be possible to reduce the product losses associated with traditional deashing processes at an economically attractive cost. The performance of these ceramic membrane microfilters is discussed.

Catalytic Ionic-Liquid Membranes: The Convergence of Ionic-Liquid Catalysis and Ionic-Liquid Membrane Separation Technologies.

Czech Academy of Sciences Publication Activity Database

Izák, Pavel; Bobbink, F.D.; Hulla, M.; Klepic, M.; Friess, K.; Hovorka, Š.; Dyson, P.J.

2018-01-01

Roč. 83, č. 1 (2018), s. 7-18 ISSN 2192-6506 R&D Projects: GA ČR(CZ) GA17-00089S; GA ČR GA17-05421S Institutional support: RVO:67985858 Keywords : heterogeneous catalysis * ionic liquids * membranes Subject RIV: CI - Industrial Chemistry, Chemical Engineering OBOR OECD: Chemical process engineering Impact factor: 2.797, year: 2016

Ionic liquid-based materials: a platform to design engineered CO2 separation membranes.

Science.gov (United States)

Tomé, Liliana C; Marrucho, Isabel M

2016-05-21

During the past decade, significant advances in ionic liquid-based materials for the development of CO2 separation membranes have been accomplished. This review presents a perspective on different strategies that use ionic liquid-based materials as a unique tuneable platform to design task-specific advanced materials for CO2 separation membranes. Based on compilation and analysis of the data hitherto reported, we provide a judicious assessment of the CO2 separation efficiency of different membranes, and highlight breakthroughs and key challenges in this field. In particular, configurations such as supported ionic liquid membranes, polymer/ionic liquid composite membranes, gelled ionic liquid membranes and poly(ionic liquid)-based membranes are detailed, discussed and evaluated in terms of their efficiency, which is attributed to their chemical and structural features. Finally, an integrated perspective on technology, economy and sustainability is provided.

Solving Problem of Graph Isomorphism by Membrane-Quantum Hybrid Model

Directory of Open Access Journals (Sweden)

Artiom Alhazov

2015-10-01

Full Text Available This work presents the application of new parallelization methods based on membrane-quantum hybrid computing to graph isomorphism problem solving. Applied membrane-quantum hybrid computational model was developed by authors. Massive parallelism of unconventional computing is used to implement classic brute force algorithm efficiently. This approach does not suppose any restrictions of considered graphs types. The estimated performance of the model is less then quadratic that makes a very good result for the problem of \\textbf{NP} complexity.

Dehydration of an ethanol/water azeotrope by novel organic-inorganic hybrid membranes based on quaternized chitosan and tetraethoxysilane.

Science.gov (United States)

Uragami, Tadashi; Katayama, Takuya; Miyata, Takashi; Tamura, Hiroshi; Shiraiwa, Tadashi; Higuchi, Akon

2004-01-01

To control swelling of quaternized chitosan (q-Chito) membranes, mixtures of q-Chito as an organic component and tetraethoxysilane (TEOS) as an inorganic component were prepared using the sol-gel reaction, and novel q-Chito/TEOS hybrid membranes were formed. In the separation of an ethanol/water azeotrope by pervaporation, the effect of TEOS content on the water/ethanol selectivity of q-Chito/TEOS hybrid membranes was investigated. Hybrid membranes containing up to 45 mol % TEOS exhibited higher water/ethanol selectivity than the q-Chito membrane. This resulted from depressed swelling of the membranes by formation of a cross-linked structure. However, introduction of excess TEOS led to greater swelling of the hybrid membranes. Therefore, the water/ethanol selectivity of the hybrid membranes containing more than 45 mol % TEOS was lower than that of the q-Chito membrane. The relationship between the structure of q-Chito/TEOS hybrid membranes and their permeation and separation characteristics during pervaporation of an ethanol/water azeotrope is discussed in detail.

Technical evaluation of hybrid membrane/DEA modeling. Topical report, January 1990-August 1990

International Nuclear Information System (INIS)

Changela, M.K.; McKee, R.L.; Reading, G.J.

1991-08-01

The report examines the potential for cost and/or performance advantages of a hybrid system, the integration of membranes and amines, over a single-stage membrane or amine system for producing pipeline quality gas on a small scale from high carbon dioxide subquality natural gas. The hybrid configuration evaluated is a membrane system in series with a conventional diethanolamine (DEA) system. Comparison of the established costs shows that each system has a region of operability. Membranes offer higher cost savings at low feed flow rates and high carbon dioxide feed contents. The hybrid system offers cost savings over moderate to high feed flow rates and for moderate to high carbon dioxide feed contents. The DEA system offers cost savings for moderate to high feed flow rates at low to moderate carbon dioxide feed contents. Membranes do not exhibit economies of scale which works to their advantage for removing carbon dioxide on a small scale. Processing costs for amine systems are more sensitive to economies of scale, and thus decrease more rapidly than for membranes at higher feed flow rates. The hybrid system offers cost savings in regions that have been perceived as exclusively amine treating applications, thus increasing the area of operability for membranes

Determination of membrane degradation products in the product water of polymer electrolyte membrane fuel cells using liquid chromatography mass spectrometry

Energy Technology Data Exchange (ETDEWEB)

Zedda, Marco

2011-05-12

The predominant long term failure of polymer electrolyte membranes (PEM) is caused by hydroxyl radicals generated during fuel cell operation. These radicals attack the polymer, leading to chain scission, unzipping and consequently to membrane decomposition products. The present work has investigated decomposition products of novel sulfonated aromatic hydrocarbon membranes on the basis of a product water analysis. Degradation products from the investigated membrane type and the possibility to detect these compounds in the product water for diagnostic purposes have not been discovered yet. This thesis demonstrates the potential of solid phase extraction and liquid chromatography tandem mass spectrometry (SPE-LC-MS/MS) for the extraction, separation, characterization, identification and quantification of membrane degradation products in the product water of fuel cells. For this purpose, several polar aromatic hydrocarbons with different functional groups were selected as model compounds for the development of reliable extraction, separation and detection methods. The results of this thesis have shown that mixed mode sorbent materials with both weak anion exchange and reversed phase retention properties are well suited for reproducible extraction of both molecules and ions from the product water. The chromatographic separation of various polar aromatic hydrocarbons was achieved by means of phase optimized liquid chromatography using a solvent gradient and on a C18 stationary phase. Sensitive and selective detection of model compounds could be successfully demonstrated by the analysis of the product water using tandem mass spectrometry. The application of a hybrid mass spectrometer (Q Trap) for the characterization of unknown polar aromatic hydrocarbons has led to the identification and confirmation of 4-hydroxybenzoic acid in the product water. In addition, 4-HBA could be verified as a degradation product resulting from PEM decomposition by hydroxyl radicals using an

Proton Conductive Channel Optimization in Methanol Resistive Hybrid Hyperbranched Polyamide Proton Exchange Membrane

Directory of Open Access Journals (Sweden)

Liying Ma

2017-12-01

Full Text Available Based on a previously developed polyamide proton conductive macromolecule, the nano-scale structure of the self-assembled proton conductive channels (PCCs is adjusted via enlarging the nano-scale pore size within the macromolecules. Hyperbranched polyamide macromolecules with different size are synthesized from different monomers to tune the nano-scale pore size within the macromolecules, and a series of hybrid membranes are prepared from these two micromoles to optimize the PCC structure in the proton exchange membrane. The optimized membrane exhibits methanol permeability low to 2.2 × 10−7 cm2/s, while the proton conductivity of the hybrid membrane can reach 0.25 S/cm at 80 °C, which was much higher than the value of the Nafion 117 membrane (0.192 S/cm. By considering the mechanical, dimensional, and the thermal properties, the hybrid hyperbranched polyamide proton exchange membrane (PEM exhibits promising application potential in direct methanol fuel cells (DMFC.

Hybrid inorganic-organic membranes: Tuning pore properties by sequential grafting

NARCIS (Netherlands)

Sripathi, V.G.P.

2014-01-01

In this thesis, the synthesis of inorganic - polymeric hybrid membranes by sequential grafting is discussed, for application in gas separation. At high pressures and temperatures, organic (olymer) membranes may suffer from swelling and plasticization. Generally, this causes a reduced molecular

Study of ion separation through solid-supported liquid membrane

International Nuclear Information System (INIS)

Kang, Young Ho; Kim, Jung Do; Kim, Kyoung Ho

1990-01-01

The membranes used in this study consist of a microporous polymeric support with the solvent contraining alamine 336, Tri-N-Octyl phosphine oxide, Tri-N-butyl phosphate, Di-(2-ethylhexyl) phosphoric acid as a carrier within the pores by the capillary forces. When this liquid membrane is interposed between aqueous feed and product solutions, the carrier serving as a complexing agent, can pick up the uranium ions on the feed side of the membrane and carry them across the membrane by diffusion. In this study, the uranium flux through the solid-supported liquid membrane was analyzed as a function of carrier concentration and acidity of the feed solution for the carrier species. Also, the Gel-liquid extraction of uranium ions from aqueous solution was performed. The adsorbents were prepared by casting the polymer solution composed of polyvinyl chloride, TOPO, and additions. The extraction of uranyl nitrate ions has been investigated as a function of TOPO/PVC ratio, evaporation time, and the stability. The results show that is maybe possible to develop an alternative uranium purification process. (author)

Feasibility of liquid membrane extraction in nuclear field. Vol. 1

Energy Technology Data Exchange (ETDEWEB)

Macasek, F [Department of Nuclear Chemistry, Comenius University SK-84215 Bratislava, (Slovakia)

1996-03-01

Membrane separation processes are widely used in separation science mainly in food and water processing. It is discussed, how far the liquid membranes, both supported and emulsion ones are suitable for trace metals, and radionuclides recovery from aqueous solutions and wastes. The advantage of liquid membranes processes are in high preconcentration capability, also emulsion membranes provides possibility to use kinetic effects for specific separation. Radiation sensitivity of the systems is considered as well as the main disadvantage because of surface active products accumulation in such systems. 3 figs.

Innovative hybrid biological reactors using membranes; Reactores biologico hibrido innovadores utilizando membranas

Energy Technology Data Exchange (ETDEWEB)

Diez, R.; Esteban-Garcia, A. L.; Florio, L. de; Rodriguez-Hernandez, L.; Tejero, I.

2011-07-01

In this paper we present two lines of research on hybrid reactors including the use of membranes, although with different functions: RBPM, biofilm reactors and membranes filtration RBSOM, supported biofilm reactors and oxygen membranes. (Author) 14 refs.

Research and development of lithium isotope separation using an ionic-liquid impregnated organic membrane

International Nuclear Information System (INIS)

Hoshino, Tsuyoshi

2013-01-01

The tritium needed as a fuel for fusion reactors is produced by the neutron capture reaction of lithium-6 ( 6 Li) in tritium breeding materials. However, natural Li contains only about 7.6 at.% 6 Li. In Japan, new lithium isotope separation technique using ionic-liquid impregnated organic membranes have been developed. The improvement in the durability of the ionic-liquid impregnated organic membrane is one of the main issues for stable, long-term operation of electrodialysis cells while maintaining good performance. Therefore, we developed highly-durable ionic-liquid impregnated organic membrane. Both ends of the ionic-liquid impregnated organic membrane were covered by a nafion 324 overcoat to prevent the outflow of the ionic liquid. The transmission of Lithium aqueous solution after 10 hours under the highly-durable ionic-liquid impregnated organic membrane is almost 13%. So this highly-durable ionic-liquid impregnated organic membrane for long operating of electrodialysis cells has been developed through successful prevention of ion liquid dissolution. (J.P.N.)

Advanced, Energy-Efficient Hybrid Membrane System for Industrial Water Reuse

Energy Technology Data Exchange (ETDEWEB)

Toy, Lora [RTI International, Research Triangle Park, NC (United States); Choi, Young Chul [RTI International, Research Triangle Park, NC (United States); Hendren, Zachary [RTI International, Research Triangle Park, NC (United States); Kim, Gyu Dong [RTI International, Research Triangle Park, NC (United States)

2017-03-31

In the U.S. manufacturing sector, current industrial water use practices are energy-intensive and utilize and discharge high volumes of waters, rendering them not sustainable especially in light of the growing scarcity of suitable water supplies. To help address this problem, the goal of this project was to develop an advanced, cost-effective, hybrid membrane-based water treatment system that can improve the energy efficiency of industrial wastewater treatment while allowing at least 50% water reuse efficiency. This hybrid process would combine emerging Forward Osmosis (FO) and Membrane Distillation (MD) technology components into an integrated FO-MD system that can beneficially utilize low-grade waste heat (i.e., T < 450 °F) in industrial facilities to produce distilled-quality product water for reuse. In this project, laboratory-, bench-, and pilot-scale experiments on the hybrid FO-MD system were conducted for industrial wastewater treatment. It was demonstrated at laboratory, bench, and pilot scales that FO-MD membrane technology can concentrate brine to very high total dissolved solids (TDS) levels (>200,000 ppm) that are at least 2.5 times higher than the TDS level to which RO can achieve. In laboratory testing, currently available FO and MD membranes were tested to select for high-performing membranes with high salt rejection and high water flux. Multiple FO membrane/draw-salt solution combinations that gave high water flux with higher than 98% salt rejection were also identified. Reverse draw-salt fluxes were observed to be much lower for divalent salts than for monovalent salts. MD membranes were identified that had 99.9+% salt rejection and water flux as high as 50-90 L/(m²·h) for flat-sheet membranes and >20 L/(m²·h) for hollow fibers. In bench-scale testing, a single unit of commercially available FO and MD membrane modules were evaluated for continuous, integrated operation. Using the laboratory- and bench-scale test data

One-step extraction of polar drugs from plasma by Parallel Artificial Liquid Membrane Extraction

DEFF Research Database (Denmark)

Pilařová, Veronika; Sultani, Mumtaz; Ask, Kristine Skoglund

2017-01-01

in the pores of a thin polymeric membrane, a well-known extraction principle also used in hollow fiber liquid-phase microextraction (HF-LPME). However, the new PALME technique offers a more user-friendly setup in which the supported liquid membrane is incorporated in a 96 well plate system. Thus, high......The new microextraction technique named parallel artificial liquid membrane extraction (PALME) was introduced as an alternative approach to liquid-liquid extraction of charged analytes from aqueous samples. The concept is based on extraction of analytes across a supported liquid membrane sustained...... for extraction of polar basic drugs was developed in the present work. The basic drugs hydralazine, ephedrine, metaraminol, salbutamol, and cimetidine were used as model analytes, and were extracted from alkalized human plasma into an aqueous solution via the supported liquid membrane. The extraction...

Supported Ionic Liquid Membranes and Ion-Jelly® Membranes with [BMIM][DCA]: Comparison of Its Performance for CO2 Separation

Directory of Open Access Journals (Sweden)

Ricardo Couto

2015-01-01

Full Text Available In this work, a supported ionic liquid membrane (SILM was prepared by impregnating a PVDF membrane with 1-butyl-3-methylimidazolium dicyanamide ([BMIM][DCA] ionic liquid. This membrane was tested for its permeability to pure gases (CO2, N2 and O2 and ideal selectivities were calculated. The SILM performance was also compared to that of Ion-Jelly® membranes, a new type of gelled membranes developed recently. It was found that the PVDF membrane presents permeabilities for pure gases similar or lower to those presented by the Ion-Jelly® membranes, but with increased ideal selectivities. This membrane presents also the highest ideal selectivity (73 for the separation of CO2 from N2 when compared with SILMs using the same PVDF support but with different ionic liquids.

Plasma-deposited hybrid silica membranes with a controlled retention of organic bridges

Energy Technology Data Exchange (ETDEWEB)

Ngamou, P.H.T.; Creatore, M. [Department of Applied Physics, Eindhoven University of Technology, 5600 MB Eindhoven (Netherlands); Overbeek, J.P.; Kreiter, R.; Van Veen, H.M.; Vente, J.F. [ECN, Energy research Centre of the Netherlands, Petten (Netherlands); Wienk, I.M.; Cuperus, P.F. [SolSep BV, Apeldoorn (Netherlands)

2013-03-05

Hybrid organically bridged silica membranes are suitable for energy-efficient molecular separations under harsh industrial conditions. Such membranes can be useful in organic solvent nanofiltration if they can be deposited on flexible, porous and large area supports. Here, we report the proof of concept for applying an expanding thermal plasma to the synthesis of perm-selective hybrid silica films from an organically bridged monomer, 1,2-bis(triethoxysilyl)ethane. This membrane is the first in its class to be produced by plasma enhanced chemical vapor deposition. By tuning the plasma and process parameters, the organic bridging groups could be retained in the separating layer. This way, a defect free film could be made with pervaporation performances of an n-butanol-water mixture comparable with those of conventional ceramic supported membranes made by sol-gel technology (i.e. a water flux of [similar]1.8 kg m'-{sup 2} h{sup -1}, a water concentration in the permeate higher than 98% and a separation factor of >1100). The obtained results show the suitability of expanding thermal plasma as a technology for the deposition of hybrid silica membranes for molecular separations.

A polymeric liquid membrane electrode responsive to 3,3',5,5'-tetramethylbenzidine oxidation for sensitive peroxidase/peroxidase mimetic-based potentiometric biosensing.

Science.gov (United States)

Wang, Xuewei; Yang, Yangang; Li, Long; Sun, Mingshuang; Yin, Haogen; Qin, Wei

2014-05-06

The oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) has great utility in bioanalysis such as peroxidase/peroxidase mimetic-based biosensing. In this paper, the behaviors of TMB oxidation intermediates/products in liquid/liquid biphasic systems have been investigated for the first time. The free radical, charge transfer complex, and diimine species generated by TMB oxidation are all positively charged under acidic and near-neutral conditions. Electron paramagnetic resonance and visible absorbance spectroscopy data demonstrate that these cationic species can be effectively transferred from an aqueous phase into a water-immiscible liquid phase functionalized by an appropriate cation exchanger. Accordingly, sensitive potential responses of TMB oxidation have been obtained on a cation exchanger-doped polymeric liquid membrane electrode under mildly acidic and near-neutral conditions. By using the membrane electrode responsive to TMB oxidations, two sensitive potentiometric biosensing schemes including the peroxidase-labeled sandwich immunoassay and G-quadruplex DNAzyme-based DNA hybridization assay have been developed. The obtained detection limits for the target antigen and DNA are 0.02 ng/mL and 0.1 nM, respectively. Coupled with other advantages such as low cost, high reliability, and ease of miniaturization and integration, the proposed polymeric liquid membrane electrode holds great promise as a facile and efficient transducer for TMB oxidation and related biosensing applications.

Natural gas purification using supported ionic liquid membrane

NARCIS (Netherlands)

Althuluth, M.A.M.; Overbeek, J.P.; Wees, H.J.; Zubeir, L.F.; Haije, W.G.; Berrouk, A.S.; Peters, C.J.; Kroon, M.C.

2015-01-01

This paper examines the possibility of the application of a supported ionic liquid membrane (SILM) for natural gas purification. The ionic liquid (IL) 1-ethyl-3-methylimidazolium tris(pentafluoroethyl)trifluorophosphate ([emim][FAP]) was impregnated successfully in the ¿-alumina layer of a tubular

Triple-bore hollow fiber membrane contactor for liquid desiccant based air dehumidification

KAUST Repository

Bettahalli Narasimha, Murthy Srivatsa

2016-04-26

Dehumidification is responsible for a large part of the energy consumption in cooling systems in high humidity environments worldwide. Improving efficiency is therefore essential. Liquid desiccants offer a promising solution for dehumidification, as desired levels of humidity removal could be easily regulated. The use of membrane contactors in combination with liquid desiccant is attractive for dehumidification because they prevent direct contact between the humid air and the desiccant, removing both the potential for desiccant carryover to the air and the potential for contamination of the liquid desiccant by dust and other airborne materials, as well as minimizing corrosion. However, the expected additional mass transport barrier of the membrane surface can lower the expected desiccation rate per unit of desiccant surface area. In this context, hollow fiber membranes present an attractive option for membrane liquid desiccant contactors because of their high surface area per unit volume. We demonstrate in this work the performance of polyvinylidene fluoride (PVDF) based triple-bore hollow fiber membranes as liquid desiccant contactors, which are permeable to water vapor but impermeable to liquid water, for dehumidification of hot and humid air.

Electrokinetic migration across artificial liquid membranes Tuning the membrane chemistry to different types of drug substances.

Science.gov (United States)

Gjelstad, Astrid; Rasmussen, Knut Einar; Pedersen-Bjergaard, Stig

2006-08-18

Twenty different basic drugs were electrokinetically extracted across a thin artificial organic liquid membrane with a 300 V d.c. electrical potential difference as the driving force. From a 300 microl aqueous sample (acidified corresponding to 10mM HCl), the drugs were extracted for 5 min through a 200 microm artificial liquid membrane of a water immiscible organic solvent immobilized in the pores of a polypropylene hollow fiber, and into a 30 microl aqueous acceptor solution of 10mM HCl inside the lumen of the hollow fiber. Hydrophobic basic drugs (logP>1.7) were effectively isolated utilizing 2-nitrophenyl octyl ether (NPOE) as the artificial liquid membrane, with recoveries up to 83%. For more hydrophilic basic drugs (logPpermeation of the interface.

PEMFC performance of MEAS based on Nafion{sup R} and sPSEBS hybrid membranes

Energy Technology Data Exchange (ETDEWEB)

Fernandez-Carretero, F.J.; Compan, V. [Univ, Politecnica de Valencia, Valencia (Spain). Dept. Termodinamica Aplicada; Suarez, K.; Solorza, O. [Inst. Politecnico Nacional, Centro de Investigacion y de Estudios Avanzados, Mexico City (Mexico). Dept. de Quimica; Riande, E. [Inst. de Ciencia y Tecnologia de Polimeros, Madrid (Spain)

2010-07-15

Important scientific, technical and economic problems must be solved before widespread commercialization of polymer electrolyte membrane fuel cells (PEMFC). The main issues facing the development of commercial low temperature fuel cells are the synthesis of efficient solid electrolytes separating the anode from the cathode as well as the development of cheaper catalysts for fuel oxidation. This study involved the preparation of hybrid membranes based on Nafion 117 and sulfonated Calprene H6120 containing partially sulfonated inorganic fillers such as silica, SBA-15 and sepiolite. The feasibility of using the membranes as polyelectrolytes for low temperature fuel cells was then evaluated. The water uptake of Nafion hybrid membranes is 1/3 to 1/4 of that in composite membranes based on sulfonated Calprene H6120. The proton conductivity of Nafion 117 hybrid membranes-electrode assemblies is nearly 1/5 of the pristine Nafion membrane assembly. Sulfonated Calprene H6120 hybrid membranes typically have better proton conductivity than the Nafion 117 composites. The performance of fuel cells containing different MEAs was examined by measuring their polarization curves in different operating conditions. The kinetic parameters governing the voltage dependence on current density were also estimated. It was concluded that the superior performance of the fuel cells with MEAs of NAF-SEP, sPSEBS-SIL and sPSEBS-SBA is not due to the membranes themselves, but to the kinetic processes that occur at the electrodes, which in this study were less efficient for fuel cells with the Nafion MEA. 34 refs., 3 tabs., 9 figs.

Identification of DNA viruses by membrane filter hybridization.

OpenAIRE

Stålhandske, P; Pettersson, U

1982-01-01

The use of membrane filter hybridization for the identification of DNA viruses is described. We designed and used a procedure for identification of herpes simplex virus. This method can discriminate between herpes simplex virus types 1 and 2 in a simple way.

Extraction by means of emulsified liquid membranes; Extraction par membranes liquides emulsionnees (MLE)

Energy Technology Data Exchange (ETDEWEB)

Pareau, D.; Stambouli, M. [Ecole Centrale de Paris, 75 (France)

2006-12-15

It is an alternative of the liquid-liquid extraction process where extraction and stripping are simultaneously carried out. The stripping solution is dispersed in the solvent in micro-droplets. This emulsion, stabilised by a surface-active agent, is then dispersed in the liquid to be treated and, during that step, the metal is transferred to the stripping solution, moving through the solvent which operates as an organic membrane. The paper describes in detail the mechanism of the process, its advantages and its disadvantages. Its field of applications is wide, but only a few units are now industrially in operation, most of them exists only at the pilot scale. It is particularly adapted for the treatment of effluents with a very low content in metallic impurities. As examples, the paper describes the recovery of zinc from viscose plant effluents (Lenzing plant, Austria) and the removal of free cyanide ions and cyanide metallic complexes (pilot scale). (authors)

Development and characterisation of hybrid polysaccharide membranes for dehydration processes.

Science.gov (United States)

Meireles, Inês T; Huertas, Rosa M; Torres, Cristiana A V; Coelhoso, Isabel M; Crespo, João G

2018-07-01

The purpose of this work is the development and characterisation of new hybrid polysaccharide (FucoPol) membranes. These membranes were prepared by incorporation of a SiO 2 network homogeneously dispersed by using a sol-gel method with GPTMS as a crosslinker silica precursor. They were further crosslinked with CaCl 2 for reinforcement of mechanical properties and improvement of their permeation performance. They were characterised in terms of their structural, mechanical and thermal properties. They presented a dense and homogeneous structure, resistant to deformation, with a Tg of 43 °C and a thermal decomposition between 240 and 251 °C. The hybrid FucoPol membranes were tested for ethanol dehydration by pervaporation and also for nitrogen dehydration. They exhibited high water selectivity values, similar to PERVAP ® 4101, however they lost their stability when exposed to solutions of 10.0 wt.% water in ethanol. In contrast, these membranes were stable when applied in N 2 dehydration, leading to reproducible performance and very high water selectivities. Copyright © 2018 Elsevier Ltd. All rights reserved.

PDMS/PVDF hybrid electrospun membrane with superhydrophobic property and drop impact dynamics for dyeing wastewater treatment using membrane distillation

KAUST Repository

An, Alicia Kyoungjin

2016-10-21

Fouling in membrane distillation (MD) results in an increase in operation costs and deterioration in a water quality. In this work, a poly(vinylidene fluoride-co-hexafluoropropene) (PVDF-HFP) electrospun (E-PH) membrane was fabricated by hybridizing polydimethylsiloxane (PDMS) polymeric microspheres with superhydrophobicity onto the E-PH membrane via electrospinning. The resulting hybrid PDMS with E-PH (E-PDMS) membrane showed a significant enhancement in surface hydrophobicity (contact angle, CA = 155.4°) and roughness (Ra = 1,285mm). The zeta potential of E-PDMS membrane surface showed a higher negative value than that of a commercial PVDF (C-PVDF) membrane. These properties of E-PDMS membrane provided an antifouling in treating of differently-charged dyes and generated a flake-like dye–dye (loosely bound foulant) structure on the membrane surface rather than in the membrane pores. This also led to a high productivity of E-PDMS membrane (34 Lm-2h-1, 50% higher than that of C-PVDF membrane) without fouling or wetting. In addition, complete color removal and pure water production were achieved during a long-term operation. An application of intermittent water flushing (WF) in direct contact MD (DCMD) operation led to a 99% CA recovery of E-PDMS membrane indicating its sustainability. Therefore, the E-PDMS membrane is a promising candidate for MD application in dyeing wastewater treatment.

Graphene oxide doped ionic liquid ultrathin composite membranes for efficient CO2 capture

KAUST Repository

Karunakaran, Madhavan

2016-11-28

Advanced membrane systems with high flux and sufficient selectivity are required for industrial gas separation processes. In order to achieve high flux and high selectivity, the membrane material should be as thin as possible and it should have selective sieving channels and long term stability. This could be achieved by designing a three component material consisting of a blend of an ionic liquid and graphene oxide covered by a highly permeable low selective polymeric coating. By using a simple dip coating technique, we prepared high flux and CO selective ultrathin graphene oxide (GO)/ionic liquid membranes on a porous ultrafiltration support. The ultrathin composite membranes derived from GO/ionic liquid complex displays remarkable combinations of permeability (CO flux: 37 GPU) and selectivity (CO/N selectivity: 130) that surpass the upper bound of ionic liquid membranes for CO/N separation. Moreover, the membranes were stable when tested for 120 hours.

Recent advances in liquid membranes and their applications in nuclear waste processing: an overview

Energy Technology Data Exchange (ETDEWEB)

Shukla, J P; Iyer, R H [Radiochemistry Division, Bhabha Atomic Research Centre, Mumbai (India)

1994-06-01

Membrane extraction, combining the processes of extraction, scrubbing and stripping in a single step, demonstrates the inherent capability of solvent extraction under non-equilibrium conditions. Permeant transport across various liquid membrane (LM) configurations, viz. bulk liquid, emulsion liquid and supported liquid membranes has great potential for applications in the nuclear field particularly in the decontamination of low and medium level radioactive wastes. Potential practical applications of such membranes have also been envisaged in the recovery of metals from hydrometallurgical leach solutions and in plutonium and americium removal from nitric acid waste streams generated by plutonium recovery operations in the PUREX process. Studies carried out have established that minor actinides like uranium, plutonium and americium from process effluents can easily be transported across polymeric and liquid type membranes through the use of specific ionophores dissolved in an appropriate liquid membrane phase. The possibility of the membrane extraction of fission palladium from acidic wastes has also been demonstrated by the use of some soft bases. An overview of these results and also some of the recent radiochemical applications of energy - efficient LM processes including directions for future research are outlined in this paper. (author). 19 refs., 1 fig., 2 tabs.

Liquid Membrane System for Extraction and Electrodeposition of Lead(II During Electrodialysis

Directory of Open Access Journals (Sweden)

Sadyrbaeva Tatiana

2017-05-01

Full Text Available A novel method for lead(II removal from aqueous acidic solutions is presented. The method involves electrodialysis through bulk liquid membranes accompanied by electrodeposition of metal from the cathodic solution. Solutions of di(2-ethylhexylphosphoric acid with admixtures of tri-n-octylamine in 1,2-dichloroethane were used as the liquid membranes. The effects of the main electrodialysis parameters as well as of the composition of the liquid membranes and aqueous solutions on the lead(II transport rate are studied. The optimal conditions are determined. A possibility of effective single-stage transfer of lead(II through the liquid membrane into dilute solutions of perchloric, nitric and acetic acids is demonstrated. Dense and adherent lead electrodeposits are obtained from perchloric acid solutions. Maximum extraction degree of 93 % and electrodeposition degree of ~60 % are obtained during 5 h of electrodialysis.

Natural Organic Matter Removal and Fouling in a Low Pressure Hybrid Membrane Systems

Directory of Open Access Journals (Sweden)

Vedat Uyak

2014-01-01

Full Text Available The objective of this study was to investigate powdered activated carbon (PAC contribution to natural organic matter (NOM removal by a submerged MF and UF hybrid systems. It was found that filtration of surface waters by a bare MF and UF membranes removed negligible TOC; by contrast, significant amounts of TOC were removed when daily added PAC particles were predeposited on the membrane surfaces. These results support the assumption that the membranes surface properties and PAC layer structure might have considerably influential factor on NOM removal. Moreover, it was concluded that the dominant removal mechanism of hybrid membrane system is adsorption of NOM within PAC layer rather than size exclusion of NOM by both of membrane pores. Transmembrane pressure (TMP increases with PAC membrane systems support the view that PAC adsorption pretreatment will not prevent the development of membrane pressure; on the contrary, PAC particles themselves caused membrane fouling by blocking the entrance of pores of MF and UF membranes. Although all three source waters have similar HPI content, it appears that the PAC interaction with the entrance of membrane pores was responsible for offsetting the NOM fractional effects on membrane fouling for these source waters.

DNA hybridization on membrane-modified carbon electrodes

Czech Academy of Sciences Publication Activity Database

Kouřilová, Alena; Babkina, S. S.; Cahová, Kateřina; Havran, Luděk; Jelen, František; Paleček, Emil; Fojta, Miroslav

2005-01-01

Roč. 38, - (2005), s. 2493-2507 ISSN 0003-2719 R&D Projects: GA MPO(CZ) 1H-PK/42; GA AV ČR(CZ) IAA4004402; GA AV ČR(CZ) IBS5004355 Institutional research plan: CEZ:AV0Z50040507 Keywords : DNA hybridization * electrochemical DNA sensor * nitrocellulose membrane Subject RIV: BO - Biophysics Impact factor: 1.036, year: 2005

Semi-interpenetrating hybrid membranes containing ADOGEN{sup ®} 364 for Cd(II) transport from HCl media

Energy Technology Data Exchange (ETDEWEB)

Mora-Tamez, Lucía; Rodríguez de San Miguel, Eduardo; Briones-Guerash, Ulrich; Munguía-Acevedo, Nadia M.; Gyves, Josefina de, E-mail: degyves@unam.mx

2014-09-15

Graphical abstract: - Highlights: • Semi-interpenetrating hybrid membranes are used for quantitative cadmium(II) recovery. • Optimization of membrane and solutions compositions is performed. • Membranes present increased stability respect to polymer inclusion membranes. • Models for cadmium (II) extraction and transport are proposed. • Excellent selectivity for Cd(II) over Ni(II), Cu(II) and Pb(II) was achieved. - Abstract: Cd(II) transport from 1 mol dm{sup −3} HCl media was investigated across semi-interpenetrating hybrid membranes (SIHMs) that were prepared by mixing an organic matrix composed of ADOGEN{sup ®} 364 as an extracting agent, cellulose triacetate as a polymeric support and nitrophenyloctyl ether as a plasticizer with an organic/inorganic network (silane phase, SP) composed of polydimethylsiloxane and a crosslinking agent. The stripping phase used was a 10{sup −2} mol dm{sup −3} ethanesulfonic acid solution. The effects of tetraorthoethoxysilane, phenyltrimethoxysilane and N′,N′-bis[3-tri(methoxysilyl)propyl]ethylendiamine as crosslinking agents on the transport were studied. H{sub 3}PO{sub 4} was used as an acid catalyst during the SP synthesis and optimized for transport performance. Solid–liquid extraction experiments were performed to determine the model that describe the transport of Cd(II) via ADOGEN{sup ®} 364. The transport was found to be chained-carrier controlled with a percolation threshold of 0.094 mmol g{sup −1}. The selective recovery of Cd(II) was studied with respect to Ni(II), Zn(II), Cu(II), and Pb(II) at a 1:1 molar ratio, and the optimized membrane system was applied for the recovery of Cd(II) from a real sample consisting of a Ni/Cd battery with satisfactory results. Finally, stability experiments were performed using the same membrane for 14 cycles. The results obtained showed that SIHMs had excellent stability and selectivity, with permeabilities comparable to those of PIMs.

Fabrication and Characterization of Polyimide-CNTs hybrid membrane to enhance high performance CO2 separation

Directory of Open Access Journals (Sweden)

Tutuk Djoko Kusworo

2015-03-01

Full Text Available This study investigates the CO2 separation performance of a hybrid membranes flat sheet based on polyimide incorporated with carbon nanotubes (CNTs particles. CNTs was selected and its loading were a 1 wt% in total solid. The hybrid composite membranes were fabricated in order to increase their separation performance for the gaseous mixture of CO2 and CH4. Hybrid Composite  membrane incorporated carbon nanotubes were mannufactured  by the dry-wet phase inversion technique using flat sheet membrane casting machine system,  in which the CNTs were embedded into the polyimide membrane and the resulting membranes were characterized. The results from the FESEM, DSC and FTIR analysis confirmed that chemical modification on carbon nanotubes surface had taken place. Sieve-in-a-cage’ morphology observed shows the poor adhesion between polymer and unmodified CNT. The results revealed that the good multi-wall carbon nanotubes dispersion leads to enhanced gas permeation properties. It is also concluded that addition of carbon nanotubes particles into the matrix of Polyimide polymer has significant effect on the membrane structure and properties.

Properties of the Nafion membrane impregnated with hydroxyl ammonium based ionic liquids

International Nuclear Information System (INIS)

Garaev, Valeriy; Pavlovica, Sanita; Vaivars, Guntars; Kleperis, Janis

2012-01-01

In this work, the Nafion 112 membrane impregnated with nine various hydroxyl ammonium based ionic liquids have been investigated. The used ionic liquids were combined from hydroxyl ammonium cations (2-hydroxyethylammonium/HEA, bis(2- hydroxyethyl)ammonium/BHEA, tris(2-hydroxyethyl)ammonium/THEA) and carboxylate anions (formate, acetate, lactate). The membranes are characterized by conductivity and thermal stability measurements. It was found, that almost all composites have 10 times higher ion conductivity than a pure Nafion 112 at 90 °C in ambient environment due to the higher thermal stability. The thermal stability of Nafion membrane was increased by all studied nine ionic liquids. In this work, only biodegradable ionic liquids were used for composite preparation.

Fabrication of Polyacrylonitrile Hollow Fiber Membranes from Ionic Liquid Solutions

KAUST Repository

Kim, Dooli; Moreno Chaparro, Nicolas; Nunes, Suzana Pereira

2015-01-01

The interest in green processes and products has increased to reduce the negative impact of many industrial processes to the environment. Solvents, which play a crucial role in the fabrication of membranes, need to be replaced by sustainable and less toxic solvent alternatives for commonly used polymers. The purpose of this study is the fabrication of greener hollow fiber membranes based on polyacrylonitrile (PAN), substituting dimethylformamide (DMF) by less toxic mixtures of ionic liquids (IL) and dimethylsulfoxide (DMSO). A thermodynamic analysis was conducted, estimating the Gibbs free energy of mixing to find the most convenient solution compositions. Hollow fiber membranes were manufactured and optimized. As a result, a uniform pattern and high porosity were observed in the inner surface of the membranes prepared from the ionic liquid solutions. The membranes were coated with a polyamide layer by interfacial polymerization the hollow fiber membranes were applied in forward osmosis experiments by using sucrose solutions as draw solution.

Fabrication of Polyacrylonitrile Hollow Fiber Membranes from Ionic Liquid Solutions

KAUST Repository

Kim, Dooli

2015-10-08

The interest in green processes and products has increased to reduce the negative impact of many industrial processes to the environment. Solvents, which play a crucial role in the fabrication of membranes, need to be replaced by sustainable and less toxic solvent alternatives for commonly used polymers. The purpose of this study is the fabrication of greener hollow fiber membranes based on polyacrylonitrile (PAN), substituting dimethylformamide (DMF) by less toxic mixtures of ionic liquids (IL) and dimethylsulfoxide (DMSO). A thermodynamic analysis was conducted, estimating the Gibbs free energy of mixing to find the most convenient solution compositions. Hollow fiber membranes were manufactured and optimized. As a result, a uniform pattern and high porosity were observed in the inner surface of the membranes prepared from the ionic liquid solutions. The membranes were coated with a polyamide layer by interfacial polymerization the hollow fiber membranes were applied in forward osmosis experiments by using sucrose solutions as draw solution.

Renewable energy powered membrane technology. 2. The effect of energy fluctuations on performance of a photovoltaic hybrid membrane system

OpenAIRE

Richards, B.S.; Capão, D.P.S.; Schäfer, Andrea

2008-01-01

This paper reports on the performance fluctuations during the operation of a batteryless hybrid ultrafiltration-nanofiltration/reverse osmosis (UF-NF/RO) membrane desalination system powered by photovoltaics treating brackish groundwater in outback Australia. The renewable energy powered membrane (RE-membrane) system is designed to supply clean drinking water to a remote community of about 50 inhabitants. The performance of the RE-membrane system over four different solar days is summarized u...

Separation of some metal ions using coupled transport supported liquid membranes

International Nuclear Information System (INIS)

Chaudhary, M.A.

1993-01-01

Liquid membrane extraction processes has become very popular due to their superiority in many ways over other separation techniques. In coupled transport membranes the metal ions can be transported across the membrane against their concentration gradient under the influence of chemical potential difference. Liquid membranes consisting of a carrier-cum-diluent, supported in microporous polymeric hydrophobic films have been studied for transport of metal ions like U(VI), Cr(VI), Be(II), V(V), Ti(IV), Zn(II), Cd(II), Hf(IV), W(VI), and Co(II). The present paper presents basic data with respect to flux and permeabilities of these metal ions across membranes based on experimental results and theoretical equations, using different carriers and diluents and provides a brief reference to possibility of such membranes for large scale applications. (author)

Enhanced Performance of Polyurethane Hybrid Membranes for CO2 Separation by Incorporating Graphene Oxide: The Relationship between Membrane Performance and Morphology of Graphene Oxide.

Science.gov (United States)

Wang, Ting; Zhao, Li; Shen, Jiang-nan; Wu, Li-guang; Van der Bruggen, Bart

2015-07-07

Polyurethane hybrid membranes containing graphene oxide (GO) with different morphologies were prepared by in situ polymerization. The separation of CO2/N2 gas mixtures was studied using these novel membranes. The results from the morphology characterization of GO samples indicated that the oxidation process in the improved Hummers method introduced oxygenated functional groups into graphite, making graphite powder exfoliate into GO nanosheets. The surface defects on the GO sheets increased when oxidation increased due to the introduction of more oxygenated functional groups. Both the increase in oxygenated functional groups on the GO surface and the decrease in the number of GO layers leads to a better distribution of GO in the polymer matrix, increasing thermal stability and gas separation performance of membranes. The addition of excess oxidant destroyed the structure of GO sheets and forms structural defects, which depressed the separation performance of membranes. The hybrid membranes containing well-distributed GO showed higher permeability and permeability selectivity for the CO2. The formation of GO aggregates in the hybrid membranes depressed the membrane performance at a high content of GO.

Parallel artificial liquid membrane extraction of acidic drugs from human plasma

DEFF Research Database (Denmark)

Roldan-Pijuan, Mercedes; Pedersen-Bjergaard, Stig; Gjelstad, Astrid

2015-01-01

The new sample preparation concept “Parallel artificial liquid membrane extraction (PALME)” was evaluated for extraction of the acidic drugs ketoprofen, fenoprofen, diclofenac, flurbiprofen, ibuprofen, and gemfibrozil from human plasma samples. Plasma samples (250 μL) were loaded into individual......-performance liquid chromatography-ultraviolet detection of the individual acceptor solutions. Important PALME parameters including the chemical composition of the liquid membrane, extraction time, and sample pH were optimized, and the extraction performance was evaluated. Except for flurbiprofen, exhaustive...

High-efficiency technology for lithium isotope separation using an ionic-liquid impregnated organic membrane

International Nuclear Information System (INIS)

Hoshino, Tsuyoshi; Terai, Takayuki

2011-01-01

The tritium needed as a fuel for fusion reactors is produced by the neutron capture reaction of lithium-6 ( 6 Li) in tritium breeding materials. New lithium isotope separation technique using ionic-liquid impregnated organic membranes (Ionic-Liquid-i-OMs) have been developed. Lithium ions are able to move by electrodialysis through certain Ionic-Liquid-i-OMs between the cathode and the anode in lithium solutions. In this report, the effects of protection cover and membrane thickness on the durability of membrane and the efficiency of isotope separation were evaluated. In order to improve the durability of the Ionic-Liquid-i-OM, we developed highly-durable Ionic-Liquid-i-OM. Both surfaces of the Ionic-Liquid-i-OM were covered by a nafion 324 overcoat or a cation exchange membrane (SELEMION TM CMD) to prevent the outflow of the ionic liquid. It was observed that the durability of the Ionic-Liquid-i-OM was improved by a nafion 324 overcoat. On the other hand, the organic membrane selected was 1, 2 or 3 mm highly-porous Teflon film, in order to efficiently impregnate the ionic liquid. The 6 Li isotope separation factor by electrodialysis using highly-porous Teflon film of 3 mm thickness was larger than using that of 1 or 2 mm thickness.

Ionic Liquids As Self-Assembly Guide for the Formation of Nanostructured Block Copolymer Membranes

KAUST Repository

Madhavan, Poornima

2015-04-30

Nanostructured block copolymer membranes were manufactured by water induced phase inversion, using ionic liquids (ILs) as cosolvents. The effect of ionic liquids on the morphology was investigated, by using polystyrene-b-poly(4-vinyl pyridine) (PS-b-PV4P) diblock as membrane copolymer matrix and imidazolium and pyridinium based ILs. The effect of IL concentration and chemical composition was evident with particular interaction with P4VP blocks. The order of block copolymer/ILs solutions previous to the membrane casting was confirmed by cryo scanning electron microscopy and the morphologies of the manufactured nanostructured membranes were characterized by transmission and scanning electron microscopy. Non-protic ionic liquids facilitate the formation of hexagonal nanoporous block copolymer structure, while protic ILs led to a lamella-structured membrane. The rheology of the IL/block copolymer solutions was investigated, evaluating the storage and loss moduli. Most membranes prepared with ionic liquid had higher water flux than pure block copolymer membranes without additives.

New displacement sensor for a hybrid magnetic bearing in liquid nitrogen

International Nuclear Information System (INIS)

Komori, M.; Kobayashi, H.; Shiraishi, C.

1999-01-01

This paper describes a newly developed displacement sensor. The displacement sensor is used for a hybrid magnetic bearing in liquid nitrogen. The principle of the displacement sensor is based on a differential transformer. The sensor is found to be useful in liquid nitrogen at 77 K (-196 C). Moreover, the sensor is applied to a hybrid magnetic bearing. The displacement sensor is found to be useful and promising

Synthesis and properties of imidazole-grafted hybrid inorganic-organic polymer membranes

International Nuclear Information System (INIS)

Li Siwen; Zhou Zhen; Liu Meilin; Li Wen; Ukai, Junzo; Hase, Kohei; Nakanishi, Masatsugu

2006-01-01

Imidazole rings were grafted on alkoxysilane with a simple nucleophilic substitute reaction to form hybrid inorganic-organic polymers with imidazole rings. Proton exchange membranes (PEM) based on these hybrid inorganic-organic polymers and H 3 PO 4 exhibit high proton conductivity and high thermal stability in an atmosphere of low relative humidity. The grafted imidazole rings improved the proton conductivity of the membranes in the high temperature range. It is found that the proton conductivities increase with H 3 PO 4 content and temperature, reaching 3.2 x 10 -3 S/cm at 110 deg. C in a dry atmosphere for a membrane with 1 mole of imidazole ring and 7 moles of H 3 PO 4 . The proton conductivity increases with relative humidity (RH) as well, reaching 4.3 x 10 -2 S/cm at 110 deg. C when the RH is increased to about 20%. Thermogravimetric analysis (TGA) indicates that these membranes are thermally stable up to 250 deg. C in dry air, implying that they have a good potential to be used as the membranes for high-temperature PEM fuel cells

Poisoning of liquid membrane carriers in extraction of metal ions

International Nuclear Information System (INIS)

Wang, Yuchun; Wang, Dexian

1992-01-01

As means of effective separation and preconcentration, emulsion liquid membranes (ELMs) have found application in many fields including biochemical separation, wastewater treatment, hydrometallurgy, and preconcentration in analytical chemistry. In the extraction of desired metal (scandium, mixed rare earths) ions using chelating extractants (TTA, HDEHP) as liquid membrane carriers, the carriers will become poisoned owing to the presence of even minute quantity of certain high ionic potential ions in the feed solution. The reason for the poisoning of carriers is that those ions have so much greater affinity than the desired ions for the membrane carrier that the ion-carrier coordination compound cannot be stripped at the interior interface of the membrane and gradually no more free carrier transports any metal ions across the membrane. The calculated results are in agreement with the experiments, and methods to avoid the poisoning are given in the paper

Electrochemical detection of dopamine using arrays of liquid-liquid micro-interfaces created within micromachined silicon membranes

International Nuclear Information System (INIS)

Berduque, Alfonso; Zazpe, Raul; Arrigan, Damien W.M.

2008-01-01

The detection of protonated dopamine by differential pulse voltammetry (DPV) and square wave voltammetry (SWV) at arrays of micro-interfaces between two immiscible electrolyte solutions (μITIES) is presented. Microfabricated porous silicon membranes (consisting of eight pores, 26.6 μm in radius and 500 μm pore-pore separation, in a hexagonal layout) were prepared by photolithographic and etching procedures. The membrane pores were fabricated with hydrophobic internal walls so that the organic phase filled the pores and created the liquid interface at the aqueous side of the membrane. These were used for harnessing the benefits of three-dimensional diffusion to the interface and for interface stabilisation. The liquid-liquid interface provides a simple method to overcome the major problem in the voltammetric detection of dopamine at solid electrodes due to the co-existence of ascorbate at higher concentrations. Selectivity for dopamine over ascorbate was achieved by the use of dibenzo-18-crown-6 (DB18C6) for the facilitated ion transfer of dopamine across the μITIES array. Under these conditions, the presence of ascorbate in excess did not interfere in the detection of dopamine and the lowest concentration detectable was ca. 0.5 μM. In addition, the drawback of current signal saturation (non-linear increase of the peak current with the concentration of dopamine) observed at conventional (millimetre-sized) liquid-liquid interfaces was overcome using the microfabricated porous membranes

Hybrid membranes PVA/silicon for use in fuel cells; Membranas hibridas de PVA/silica para aplicacao em celula a combustivel

Energy Technology Data Exchange (ETDEWEB)

Aguiar, Liz C.V. de; Almeida, Raquel D. de; Gomes, Ailton de S. [Universidade Federal do Rio de Janeiro - UFRJ, Instituto de Macromoleculas Professora Eloisa Mano - IMA, RJ (Brazil)], e-mail: lizcontino@ima.ufrj.br; Ramos Filho, Florencio G. de [Centro Universitario Estadual da Zona Oeste - UEZO, Rio de Janeiro, RJ (Brazil)

2011-07-01

Hybrids organic-inorganic membranes PVA-silica have been prepared using sol-gel process in situ with the objective of study the influence of inorganic particles incorporation on the water uptake, pervaporation and proton conductivity of PVA membranes. The silica was constituted of mercaptopropyltrimethoxysilane (MPTMS) with or without the mixture with the tetra ethoxysilane (TEOS). The hybrids membranes were oxidated to convert the -SH groups in -SO{sub 3}H groups, becoming them proton conducting. The hybrids membranes not oxidated showed lesser water uptake and pervaporated material, probably, due to the formation of crosslink that restricted the swell of the PVA membrane. The protonic conductivity of the hybrid membranes after the oxidation was up to 26 times bigger than of the membrane not oxidated. (author)

Novel composite membranes based on PBI and dicationic ionic liquids for high temperature polymer electrolyte membrane fuel cells

International Nuclear Information System (INIS)

Hooshyari, Khadijeh; Javanbakht, Mehran; Adibi, Mina

2016-01-01

Two types of innovative composite membranes based on polybenzimidazole (PBI) containing dicationic ionic liquid 1,3-di(3-methylimidazolium) propane bis (trifluoromethylsulfonyl) imide (PDC 3 ) and monocationic ionic liquid 1-hexyl-3-methylimidazolium bis (trifluoromethanesulfonyl) imide (PMC 6 ) are prepared as electrolyte for high temperature fuel cells applications under anhydrous conditions. The analyses of results display promising characteristics such as high proton conductivity and thermal stability. Moreover the fuel cell performance of PA doped PDC 3 composite membranes is enhanced in comparison with PA doped PMC 6 and PA doped PBI membranes at high temperatures. Dicationic ionic liquid with high number of charge carriers provides well-developed ionic channels which form facile pathways and considerably develop the anhydrous proton conductivity. The highest proton conductivity of 81 mS/cm is achieved for PA doped PDC 3 composite membranes with PBI/IL mole ratio: 4 at 180 °C. A power density of 0.44 W/cm 2 is obtained at 0.5 V and 180 °C for PA doped PDC 3 composite membranes, which proves that these developed composite membranes can be considered as most promising candidates for high temperature fuel cell applications with enhanced proton conductivity.

Use of membrane separation processes for the separation of radionuclides from liquid and gas streams

International Nuclear Information System (INIS)

Vladisavljevic, G.T.; Rajkovic, M.B.

1999-01-01

Use of membranes for the separation and recovery of radionuclides from contaminated liquid and gas streams has been discussed in this paper. The special attention has been paid to the use of ion-exchange membranes for electrodialysis and Donnan dialysis, as well as the use of facilitated liquid membranes for liquid pertraction. (author)

Modeling CO2-facilitated transport across a diethanolamine liquid membrane

Energy Technology Data Exchange (ETDEWEB)

Lihong Bao; Michael C. Trachtenberg [Carbozyme Inc., Monmouth Junction, NJ (United States)

2005-12-15

We compared experimental and model data for the facilitated transport of CO2 from a CO2-air mixture across an aqueous solution of diethanolamine (DEA) via a hollow fiber, contained liquid membrane (HFCLM) permeator. A two-step carbamate formation model was devised to analyze the data instead of the one-step mechanism used by previous investigators. The effects of DEA concentration, liquid membrane thickness and feed CO2 concentration were also studied. With a 20% (wt) DEA liquid membrane and feed of 15% CO2 in CO2-air mixture at atmosphere pressure, the permeance reached 1.51E-8 mol/m{sup 2} s Pa with a CO2/N2 selectivity of 115. Model predictions compared well with the experimental results at CO2 concentrations of industrial importance. Short-term stability of the HFCLM permeator performance was examined. The system was stable during 5-days of testing.

Potential of membrane processes in management of radioactive liquid waste

International Nuclear Information System (INIS)

Kumar, Surender; Jain, Savita; Raj, Kanwar

2010-01-01

Various categories of radioactive liquid waste are generated during operations and maintenance of nuclear installations. The potential of membrane processes for the treatment of low-level radioactive liquids is discussed in this paper

Uranium extraction process in a sulfuric medium by means of liquid emulsified membranes

International Nuclear Information System (INIS)

Monteillet, A.

1985-02-01

Uranium ore processing, after leaching by sulfuric acid, by liquid-liquid extraction is a rather heavy process, not suitable for small deposits. Extraction by emulsions was suggested. In this process the leachate is contacted with an oil in water type emulsion, a liquid organic membrane is formed by the continuous phase. Uranium complexes diffuse through the liquid membrane towards the dispersed aqueous phase of the emulsion (stripping solution). Uranium is recovered by breaking the emulsion. Are successively studied: development of stable emulsions, influence of emulsion composition on uranium transfer kinetics, transfer mechanisms through the membrane and modelling of kinetics data obtained in the experimental study [fr

Carrier-mediated transport of actinides and rare earth elements through liquid and plasticized membranes

International Nuclear Information System (INIS)

Kopunec, R.; Ngo Manh, Th.

1994-01-01

The first works in this field were realized approximately 25 years ago, when BLOCK et al. reported their studies about carrier-mediated transport (also called pertraction or membrane extraction) of uranium through plasticized membranes with neutral esters derived from phosphoric acid. At this time, the methodical principles of selective pertraction of ionic compounds through so-called bulk liquid membranes containing carriers were known. However, these membranes, similarly as plasticized membranes, have not achieved a broader use. This is probably because bulk liquid membranes are from a technical point of view fairly distant from the idea of a typical membrane system, and plasticized membranes (sometimes also called gel membranes) present great resistance. By the end of the 1960's and at the beginning of the 1970's, LI and CUSSLER worked out the principles for two widely used pertraction techniques, called pertraction through emulsion liquid and supported liquid membranes (ELM and SLM). These two techniques not only have greatest significance in laboratory practice, but they also are interesting for technological aims because of the attainable large phase boundaries, e.g. 10 3 -10 4 m 2 /m 3 . Many ways to arrange membrane systems are described in papers. Recently, the significance of carrier-mediated transport through liquid membranes has grown to have (since 1980) separate section at the International Solvent Extraction Conference. This paper does not deal with mathematical models and the mechanism of pertraction in general, but it gives an overview of results obtained in publications referring to pertraction of two related element groups - actinoids and rare earth elements - using various membrane types. (author) 154 refs

Boron Removal in Radioactive Liquid Waste by Forward Osmosis Membrane

Energy Technology Data Exchange (ETDEWEB)

Hwang, Dooseong; Choi, Hei Min; Lee, Kune Woo; Moon Jeikwon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2014-05-15

These wastes contain about 0.3-0.8 wt% boric acid and have been concentrated through an evaporation treatment. Boric acid tends to crystallize owing to its solubility, and to plug the evaporator. The volume reduction obtained through evaporation is limited by the amount of boric acid in the waste. As an emerging technology, forward osmosis (FO) has attracted growing interest in wastewater treatment and desalination. FO is a membrane process in which water flows across a semi-permeable membrane from a feed solution of lower osmotic pressure to a draw solution of higher osmotic pressure. However, very few studies on the removal of boron by FO have been performed. The objective of this study is to evaluate the possibility of boron separation in radioactive liquid waste by FO. In this study, the performance of FO was investigated to separate boron in the simulated liquid waste under the factors such as pH, osmotic pressure, ionic strength of the solution, and membrane characteristic. The boron separation in radioactive borate liquid waste was investigated with an FO membrane. When the feed solution containing boron is treated by the FO membrane, the boron permeation depends on the type of membrane, membrane orientation, pH of the feed solution, salt and boron concentration in the feed solution, and osmotic pressure of the draw solution. The boron flux begins to decline from pH 7, and increases with an increase in the osmotic driving force. The boron flux of the CTA-ES and ALFD membrane orientation is higher than those of the CTA-NW and ALFF orientation, respectively. The boron permeation rate is constant regardless of the osmotic pressure and membrane orientation. The boron flux decreases slightly with the salt concentration, but it is not heavily influenced at a low salt concentration.

Boron Removal in Radioactive Liquid Waste by Forward Osmosis Membrane

International Nuclear Information System (INIS)

Hwang, Dooseong; Choi, Hei Min; Lee, Kune Woo; Moon Jeikwon

2014-01-01

These wastes contain about 0.3-0.8 wt% boric acid and have been concentrated through an evaporation treatment. Boric acid tends to crystallize owing to its solubility, and to plug the evaporator. The volume reduction obtained through evaporation is limited by the amount of boric acid in the waste. As an emerging technology, forward osmosis (FO) has attracted growing interest in wastewater treatment and desalination. FO is a membrane process in which water flows across a semi-permeable membrane from a feed solution of lower osmotic pressure to a draw solution of higher osmotic pressure. However, very few studies on the removal of boron by FO have been performed. The objective of this study is to evaluate the possibility of boron separation in radioactive liquid waste by FO. In this study, the performance of FO was investigated to separate boron in the simulated liquid waste under the factors such as pH, osmotic pressure, ionic strength of the solution, and membrane characteristic. The boron separation in radioactive borate liquid waste was investigated with an FO membrane. When the feed solution containing boron is treated by the FO membrane, the boron permeation depends on the type of membrane, membrane orientation, pH of the feed solution, salt and boron concentration in the feed solution, and osmotic pressure of the draw solution. The boron flux begins to decline from pH 7, and increases with an increase in the osmotic driving force. The boron flux of the CTA-ES and ALFD membrane orientation is higher than those of the CTA-NW and ALFF orientation, respectively. The boron permeation rate is constant regardless of the osmotic pressure and membrane orientation. The boron flux decreases slightly with the salt concentration, but it is not heavily influenced at a low salt concentration

Polyethersulfone flat sheet and hollow fiber membranes from solutions in ionic liquids

KAUST Repository

Kim, Dooli

2017-06-10

We fabricated flat-sheet and hollow fiber membranes from polyethersulfone (PES) solutions in two ionic liquids: 1-ethyl-3-methylimidazolium diethyl phosphate ([EMIM]DEP) and 1,3-dimethylimidazolium dimethyl phosphate ([MMIM]DMP). The solvents are non-volatile and less toxic than organic solvents, such as dimethylformamide (DMF). The membranes morphologies were compared with those of membranes prepared from solutions in DMF, using electron microscopy. Water permeance, solute rejection and mechanical strengths were evaluated. Membranes were applied to DNA separation. While membranes based on PES were successfully prepared, polysulfone (PSf) does not dissolve in the same ionic liquids. The discrepancy between PES and PSf could not be explained using classical Flory-Huggins theory, which does not consider the coulombic contributions in ionic liquids. The differences in solubility could be understood, by applying density functional theory to estimate the interaction energy between the different polymers and solvents. The theoretical results were supported by experimental measurements of intrinsic viscosity and dynamic light scattering (DLS).

Experimental investigations on performance of liquid desiccant-vapor compression hybrid air conditioner

International Nuclear Information System (INIS)

Mohan, B. Shaji; Tiwari, Shaligram; Maiya, M.P.

2015-01-01

A coupled desiccant column is integrated with a conventional room air conditioner (AC) to enhance dehumidification of the room air. One desiccant column (absorber) is placed after the evaporator the other (regenerator) after the condenser of the AC unit. Such a novel liquid desiccant vapour compression hybrid air conditioning system has been fabricated and tested in a balanced ambient room type calorimeter for very low flow rates of liquid desiccant (lithium bromide solution). The moisture from the cold supply air is transferred to the hot condenser air by the desiccant flowing in the loop, thereby complimenting the dehumidification of the room air at the evaporator. The supply air is also sensibly heated during the dehumidification process by liquid desiccant in the absorber, which together enables the hybrid system to maintain low humidity in the room. Whereas the liquid desiccant is regenerated by the condenser waste heat, the entire cooling is derived only by the AC unit. The experimental results show that an increase of room temperature reduces both dehumidification of process air and regeneration of liquid desiccant, whereas an increase of room specific humidity enhances both these for the flow rate of the liquid desiccant in the range of 0.2–1.6% of the air flow rate through the absorber. - Highlights: • A liquid desiccant vapor compression hybrid system is fabricated and tested. • The liquid desiccant reduces latent load but equally increases sensible load. • Hybrid system performance is studied for varying room temperature and humidity. • Higher room temperature lowers air dehumidification and desiccant regeneration. • Increase of room specific humidity enhances dehumidification and also regeneration

Ionic-Liquid-Tethered Nanoparticles: Hybrid Electrolytes

KAUST Repository

Moganty, Surya S.

2010-10-22

A new class of solventless electrolytes was created by tethering ionic liquids to hard inorganic ZrO2 nanostructures (see picture; NIM=nanoscale ionic material). These hybrid fluids exhibit exceptional redox stability windows, excellent thermal stability, good lithium transference numbers, long-term interfacial stability in the presence of a lithium anode and, when doped with lithium salt, reasonable ionic conductivities.

Architecture, Assembly, and Emerging Applications of Branched Functional Polyelectrolytes and Poly(ionic liquid)s.

Science.gov (United States)

Xu, Weinan; Ledin, Petr A; Shevchenko, Valery V; Tsukruk, Vladimir V

2015-06-17

Branched polyelectrolytes with cylindrical brush, dendritic, hyperbranched, grafted, and star architectures bearing ionizable functional groups possess complex and unique assembly behavior in solution at surfaces and interfaces as compared to their linear counterparts. This review summarizes the recent developments in the introduction of various architectures and understanding of the assembly behavior of branched polyelectrolytes with a focus on functional polyelectrolytes and poly(ionic liquid)s with responsive properties. The branched polyelectrolytes and poly(ionic liquid)s interact electrostatically with small molecules, linear polyelectrolytes, or other branched polyelectrolytes to form assemblies of hybrid nanoparticles, multilayer thin films, responsive microcapsules, and ion-conductive membranes. The branched structures lead to unconventional assemblies and complex hierarchical structures with responsive properties as summarized in this review. Finally, we discuss prospectives for emerging applications of branched polyelectrolytes and poly(ionic liquid)s for energy harvesting and storage, controlled delivery, chemical microreactors, adaptive surfaces, and ion-exchange membranes.

Hybrid Multiphase CFD Solver for Coupled Dispersed/Segregated Flows in Liquid-Liquid Extraction

Directory of Open Access Journals (Sweden)

Kent E. Wardle

2013-01-01

Full Text Available The flows in stage-wise liquid-liquid extraction devices include both phase segregated and dispersed flow regimes. As a additional layer of complexity, for extraction equipment such as the annular centrifugal contactor, free-surface flows also play a critical role in both the mixing and separation regions of the device and cannot be neglected. Traditionally, computional fluid dynamics (CFD of multiphase systems is regime dependent—different methods are used for segregated and dispersed flows. A hybrid multiphase method based on the combination of an Eulerian multifluid solution framework (per-phase momentum equations and sharp interface capturing using Volume of Fluid (VOF on selected phase pairs has been developed using the open-source CFD toolkit OpenFOAM. Demonstration of the solver capability is presented through various examples relevant to liquid-liquid extraction device flows including three-phase, liquid-liquid-air simulations in which a sharp interface is maintained between each liquid and air, but dispersed phase modeling is used for the liquid-liquid interactions.

Selectivity of NF membrane for treatment of liquid waste containing uranium

International Nuclear Information System (INIS)

Oliveira, Elizabeth E.M.; Barbosa, Celina C.R.; Afonso, Julio C.

2013-01-01

The performance of two nanofiltration membranes were investigated for treatment of liquid waste containing uranium through two conditions permeation: permeation test and concentration test of the waste. In the permeation test solution permeated returned to the feed tank after collected samples each 3 hours. In the test of concentration the permeated was collected continuously until 90% reduction of the feed volume. The liquid waste ('carbonated water') was obtained during conversion of UF 6 to UO 2 in the cycle of nuclear fuel. This waste contains uranium concentration on average 7.0 mg L -1 , and not be eliminated to the environmental. The waste was permeated using a cross-flow membrane cell in the pressure of the 1.5 MPa. The selectivity of the membranes for separation of uranium was between 83% and 90% for both tests. In the concentration tests the waste was concentrated around for 5 times. The surface layer of the membranes was evaluated before and after the tests by infrared spectroscopy (ATR-FTIR), field emission microscopy (FESEM) and atomic force spectroscopy (AFM). The membrane separation process is a technique feasible to and very satisfactory for treatment the liquid waste. (author)

The Tower: Modelling, Analysis and Construction of Bending Active Tensile Membrane Hybrid Structures

DEFF Research Database (Denmark)

Holden Deleuran, Anders; Schmeck, Michel; Charles Quinn, Gregory

2015-01-01

The project is the result of an interdisciplinary research collaboration between CITA, KET and Fibrenamics exploring the design of integrated hybrid structures employing bending active elements and tensile membranes with bespoke material properties and detailing. Hybrid structures are defined her...

Effect of membrane properties on the performance of a hybrid GAC and ultrafiltration process for water treatment.

Science.gov (United States)

Qiao, Tiejun; Wu, Guangxue; Zhang, Xihui; Au, Doris W T; Zhang, Jinsong

2012-06-01

The performance of a hybrid granular activated carbon (GAC) and ultrafiltration (UF) process for water treatment was investigated using five types of UF membranes. The removal percentages for chemical oxygen demand (COD(Mn)), particles (> or = 2 microm) and total bacteria by the hybrid process were 30-40%, 98-99% and 76-92%, respectively. No invertebrates were detected in the hybrid process effluent. Transmembrane pressure and specific permeate flux (SPF) of the five types of membranes varied. With decreasing membrane pore sizes, removal of COD(Mn) and particles increased, whereas SPF firstly decreased and then increased. Hydrophilic membranes had a relatively high COD(Mn) removal potential, but did not obviously affect particle removal or SPF.

Various methods for determination of liquid viscosity with nuclear track membranes

International Nuclear Information System (INIS)

Guo Shilun

1991-01-01

A systematic study has been performed of the methods for determination of liquid viscosity with nuclear track membranes. Absolute and relative measurements have been suggested, the latter including relative measurements of absolute viscosity and kinematic viscosity. The study shows that the nuclear track membrane is a unique element for determination of liquid viscosity because it is small in volume, accurate in results and easy to manipulate in industries and laboratories

Performance of Hybrid Photocatalytic-Ceramic Membrane System for the Treatment of Secondary Effluent.

Science.gov (United States)

Song, Lili; Zhu, Bo; Gray, Stephen; Duke, Mikel; Muthukumaran, Shobha

2017-03-28

Evaluation of an advanced wastewater treatment system that combines photocatalysis with ceramic membrane filtration for the treatment of secondary effluent was undertaken. The results showed that, after photocatalysis and ceramic membrane filtration, the removal of dissolved organic carbon and UV 254 was 60% and 54%, respectively, at a concentration of 4 g/L of TiO₂. Dissolved organic matter (DOM) present in the secondary effluent was characterised with a liquid chromatography-organic carbon detector (LC-OCD) technique. The results showed low removal of humics, building blocks, the other oxidation by-products and no removal of biopolymers after TiO₂/UV photocatalytic treatment. This suggested that the radical non-selective oxidation mechanisms of TiO₂/UV process resulted in secondary effluent in which all of the DOM fractions were present. However, the hybrid system was effective for removing biopolymers with the exception of low molecular weight (LMW) compounds acids, which accumulated from the beginning of the reaction. In addition, monitoring of the DOM fractions with LC-OCD analysis demonstrated that the reduction of the effluent aromaticity was not firmly correlated with the removal of humic substances for the combined processes.

Membrane Separation Processes for Post-Combustion Carbon Dioxide Capture: State of the Art and Critical Overview

Directory of Open Access Journals (Sweden)

Belaissaoui Bouchra

2014-11-01

Full Text Available Membrane processes have been initially seldom considered within a post-combustion carbon dioxide capture framework. More traditional processes, particularly gas-liquid absorption in chemical solvents, are often considered as the most appropriate solution for the first generation of technologies. In this paper, a critical state of the art of gas separation membranes for CO2 capture is proposed. In a first step, the key performances (selectivity, permeability of different membrane materials such as polymers, inorganic membranes, hybrid matrices and liquid membranes, including recently reported results, are reviewed. In a second step, the process design characteristics of a single stage membrane unit are studied. Purity and energy constraints are analysed as a function of operating conditions and membrane materials performances. The interest of multistage and hybrid systems, two domains which have not sufficiently investigated up to now, are finally discussed. The importance of technico-economical analyses is highlighted in order to better estimate the optimal role of membranes for CCS applications.

Engineering a self-driven PVDF/PDA hybrid membranes based on membrane micro-reactor effect to achieve super-hydrophilicity, excellent antifouling properties and hemocompatibility

Science.gov (United States)

Li, Jian-Hua; Ni, Xing-Xing; Zhang, De-Bin; Zheng, Hui; Wang, Jia-Bin; Zhang, Qi-Qing

2018-06-01

A facile and versatile approach for the preparation of super-hydrophilic, excellent antifouling and hemocompatibility membranes had been developed through the generation in situ of bio-inspired polydopamine (PDA) microspheres on PVDF membranes. SEM images showed that the PDA microspheres were uniformly dispersed on the upper surface and the lower surface of the modified membranes. And there were a great number of PDA microspheres immobilized on the cross-section, but the interconnected pores structure was not destroyed. These facts indicated the existence of membrane micro-reactor effect for the whole membrane structure. Considering the remarkable improvement of hydrophilicity, antifouling properties, and permeation fluxes, we also proposed the cluster phenolic hydroxyl effect for the PVDF/PDA hybrid membranes. And the cluster phenolic hydroxyl effect can be ascribed to the all directions distributed phenolic hydroxyl groups on the whole membrane structure. Besides, the self-driven filtration experiments showed the great wetting ability and permeability of the PVDF/PDA hybrid membranes in filtration process without any external pressure. This implied the existence of accelerating self-driven force after the water flow flowed into the internal of membranes, which contributed to the increase of water flow velocity. All the three aspects were in favor of the enhancement of hydrophilicity, antifouling properties and permeability of the modified membranes. Moreover, the conventional filtration tests, oil/water emulsion filtration tests and protein adsorption tests were also carried out to discuss the practical applications of PVDF/PDA hybrid membranes. And the hemocompatibility of the modified membranes was also proved to enhance greatly through the hemolysis tests and platelet adhesion tests, indicating that the membranes were greatly promising in biomedical applications. The strategy of material modification reported here is substrate-independent and can be extended

Separation of Gas Mixtures by New Type of Membranes – Dynamic Liquid Membranes.

Czech Academy of Sciences Publication Activity Database

Setničková, Kateřina; Šíma, Vladimír; Petričkovič, Roman; Řezníčková Čermáková, Jiřina; Uchytil, Petr

2016-01-01

Roč. 160, FEB 29 (2016), s. 132-135 ISSN 1383-5866 Institutional support: RVO:67985858 Keywords : gas separation * liquid membrane * methane Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 3.359, year: 2016

(Meth)acrylate liquid crystalline polymers for membrane applications

Czech Academy of Sciences Publication Activity Database

Rabie, F.; Sedláková, Zdeňka; Sheth, S.; Marand, E.; Martin, S. M.; Poláková, Lenka

2015-01-01

Roč. 132, č. 43 (2015), 42694_1-42694_8 ISSN 0021-8995 Institutional support: RVO:61389013 Keywords : copolymers * liquid crystals * membranes Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.866, year: 2015

Dicyclohexano-18-crown-6 as a novel carrier in the liquid membrane permeation of actinides

International Nuclear Information System (INIS)

Kumar, Anil; Singh, R.K.; Bajpai, D.D.; Shukla, J.P.

1994-01-01

The proven extractability and profound selectivity of dicyclohexano-18-crown-6 (DC18C6) has been exploited by selecting this crown ether as the ionophore in liquid membrane transport. Macrocycle-facilitated transport of Pu(IV) and U(VI) against their concentration gradient from aqueous nitric acid solutions across organic bulk liquid membrane (BLM) and thin-sheet supported liquid membrane (SLM) containing DC18C6 as the mobile carrier and toluene as the membrane solvent was investigated. (author). 23 refs., 9 tabs., 7 figs

High-performance hybrid pervaporation membranes with superior hydrothermal and acid stability

Energy Technology Data Exchange (ETDEWEB)

Castricum, H.L. [Inorganic Materials Science, MESA Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede (Netherlands); Blank, D.H.A.; Ten Elshof, J.E. [Van ' t Hoff Institute for Molecular Sciences, University of Amsterdam, Nieuwe Achtergracht 166, 1018 WV Amsterdam (Netherlands); Kreiter, R.; Van Veen, H.M.; Vente, J.F. [ECN Efficiency and Infrastructure, Petten (Netherlands)

2009-05-15

A new organic-inorganic hybrid membrane has been prepared with exceptional performance in dewatering applications. The only precursor used in the sol-gel synthesis of the selective layer was organically linked 1,2-bis(triethoxysilyl)ethane (BTESE). The microporous structure of this layer enables selective molecular sieving of small molecules from larger ones. In the dehydration of n-butanol with 5% of water, the membrane shows a high separation factor of over 4000 and ultra-fast water transport at a rate of more than 20 kg m{sup -2} h{sup -1} at 150C. This can be related to the high adsorption capacity of the material and the sub-micron thickness of the selective layer. The selectivity has now remained constant over almost one and a half years under continuous process testing conditions. Apart from the hydrothermal stability, the membrane exhibits a high tolerance for acid contamination. A slow performance decline in flux and separation factor is only observed at a pH lower than 2. The high stability and effective separation indicate a broad industrial application potential of the hybrid membrane material.

Enhanced the performance of graphene oxide/polyimide hybrid membrane for CO2 separation by surface modification of graphene oxide using polyethylene glycol

Science.gov (United States)

Wu, Li-guang; Yang, Cai-hong; Wang, Ting; Zhang, Xue-yang

2018-05-01

Polyethylene glycol (PEG) with different molecular weights was first used to modify graphene oxide (GO) samples. Subsequently, polyimide (PI) hybrid membranes containing modified-GO were fabricated via in situ polymerization. The separation performance of these hybrid membranes was evaluated using permeation experiments for CO2 and N2 gases. The morphology characterization showed that PEG with suitable molecular weight could be successfully grafted on the GO surface. PEG modification altered the surface properties of GO and introduced defective structures onto GO surface. This caused strong surface polarity and high free volume of membranes containing PEG-modified GO, thereby improving the separation performance of membranes. The addition of PEG-GO with low molecular weight effectively increased gas diffusion through hybrid membranes. The hybrid membranes containing PEG-GO with large molecular weight had high solubility performance for CO2 gas due to the introduction of numerous polar groups into polymeric membranes. With the loading content of modified GO, the CO2 gas permeability of hybrid membranes initially increased but eventually decreased. The optimal content of modified GO in membranes reached 3.0 wt%. When too much PEG added (exceeding 30 g), some impurities formed on GO surface and some aggregates appeared in the resulting hybrid membrane, which depressed the membrane performance.

Hollow fibre supported liquid membrane extraction of ...

African Journals Online (AJOL)

A simple sample pre-treatment method utilizing hollow fibre supported liquid membrane (HFSLM) was carried out on pharmaceuticals samples comprising of cough syrups (CS1 and CS2) and an anti-inflammatory product (AI). The active ingredients targeted in the extraction process were diphenylhydramine (DPH), ...

Novel acid-base hybrid membrane based on amine-functionalized reduced graphene oxide and sulfonated polyimide for vanadium redox flow battery

International Nuclear Information System (INIS)

Cao, Li; Sun, Qingqing; Gao, Yahui; Liu, Luntao; Shi, Haifeng

2015-01-01

A series of novel acid-base hybrid membranes (SPI/PEI-rGO) based on sulfonated polyimide (SPI) with polyethyleneimine-functionalized reduced graphene oxide (PEI-rGO) are prepared by a solution-casting method for vanadium redox flow battery (VRB). FT-IR and XPS results prove the successful fabrication of PEI-rGO and SPI/PEI-rGO hybrid membranes, which show a dense and homogeneous structure observed by SEM. The physicochemical properties such as water uptake, swelling ratio, ion exchange capacity, proton conductivity and vanadium ion permeability are well controlled by the incorporated PEI-rGO fillers. The interfacial-formed acid-base pairs between PEI-rGO and SPI matrix effectively reduce the swelling ratio and vanadium ion permeability, increasing the stability performance of the hybrid membranes. SPI/PEI-rGO-2 hybrid membrane exhibits a higher coulombic efficiency (CE, 95%) and energy efficiency (EE, 75.6%) at 40 mA cm −2 , as compared with Nafion 117 membrane (CE, 91% and EE, 66.8%). The self-discharge time of the VRB with SPI/PEI-rGO-2 hybrid membrane (80 h) is longer than that of Nafion 117 membrane (26 h), demonstrating the excellent blocking ability for vanadium ion. After 100 charge-discharge cycles, SPI/PEI-rGO-2 membrane exhibits the good stability under strong oxidizing and acid condition, proving that SPI/PEI-rGO acid-base hybrid membranes could be used as the promising candidates for VRB applications

Ionic liquid-nanoparticle hybrid electrolytes

KAUST Repository

Lu, Yingying

2012-01-01

We investigate physical and electrochemical properties of a family of organic-inorganic hybrid electrolytes based on the ionic liquid 1-methyl-3-propylimidazolium bis(trifluoromethanesulfone) imide covalently tethered to silica nanoparticles (SiO 2-IL-TFSI). The ionic conductivity exhibits a pronounced maximum versus LiTFSI composition, and in mixtures containing 13.4 wt% LiTFSI, the room-temperature ionic conductivity is enhanced by over 3 orders of magnitude relative to either of the mixture components, without compromising lithium transference number. The SiO 2-IL-TFSI/LiTFSI hybrid electrolytes are thermally stable up to 400°C and exhibit tunable mechanical properties and attractive (4.25V) electrochemical stability in the presence of metallic lithium. We explain these observations in terms of ionic coupling between counterion species in the mobile and immobile (particle-tethered) phases of the electrolytes. © 2012 The Royal Society of Chemistry.

Template-mediated synthesis of periodic membranes for improved liquid-phase separations

International Nuclear Information System (INIS)

Groger, H.

1997-01-01

Solid/liquid separations of particulates in waste streams will benefit from design and development of ultrafiltration (UF) membranes with uniform, tailorable pore size and chemical, thermal, and mechanical stability. Such membranes will perform solid/liquid separations with high selectivity, permeance, lifetime, and low operating costs. Existing organic and inorganic membrane materials do not adequately meet all these requirements. An innovative solution to the need for improved inorganic membranes is the application of mesoporous ceramics with narrow pore-size distributions and tailorable pore size (1.5 to 10 nm) that have recently been shown to form with the use of organic surfactant molecules and surfactant assemblies as removable templates. This series of porous ceramics, designated MCM-41, consists of silica or aluminosilicates distinguished by periodic arrays of uniform channels. In this Phase I Small Business Innovation Research program, American Research Corporation of Virginia will demonstrate the use of supported MCM-41 thin films deposited by a proprietary technique, as UF membranes. Technical objectives include deposition in thin, defect-free periodic mesoporous MCM-41 membranes on porous supports; measurement of membrane separation factors, permeance, and fouling; and measurement of membrane lifetime as part of an engineering and economic analysis

Template-mediated synthesis of periodic membranes for improved liquid-phase separations

Energy Technology Data Exchange (ETDEWEB)

Groger, H. [American Research Corp. of Virginia, Radford, VA (United States)

1997-10-01

Solid/liquid separations of particulates in waste streams will benefit from design and development of ultrafiltration (UF) membranes with uniform, tailorable pore size and chemical, thermal, and mechanical stability. Such membranes will perform solid/liquid separations with high selectivity, permeance, lifetime, and low operating costs. Existing organic and inorganic membrane materials do not adequately meet all these requirements. An innovative solution to the need for improved inorganic membranes is the application of mesoporous ceramics with narrow pore-size distributions and tailorable pore size (1.5 to 10 nm) that have recently been shown to form with the use of organic surfactant molecules and surfactant assemblies as removable templates. This series of porous ceramics, designated MCM-41, consists of silica or aluminosilicates distinguished by periodic arrays of uniform channels. In this Phase I Small Business Innovation Research program, American Research Corporation of Virginia will demonstrate the use of supported MCM-41 thin films deposited by a proprietary technique, as UF membranes. Technical objectives include deposition in thin, defect-free periodic mesoporous MCM-41 membranes on porous supports; measurement of membrane separation factors, permeance, and fouling; and measurement of membrane lifetime as part of an engineering and economic analysis.

Influence of fermentation liquid from waste activated sludge on anoxic/oxic- membrane bioreactor performance: Nitrogen removal, membrane fouling and microbial community.

Science.gov (United States)

Han, Xiaomeng; Zhou, Zhen; Mei, Xiaojie; Ma, Yan; Xie, Zhenfang

2018-02-01

In order to investigate effects of waste activated sludge (WAS) fermentation liquid on anoxic/oxic- membrane bioreactor (A/O-MBR), two A/O-MBRs with and without WAS fermentation liquid addition were operated in parallel. Results show that addition of WAS fermentation liquid clearly improved denitrification efficiency without deterioration of nitrification, while severe membrane fouling occurred. WAS fermentation liquid resulted in an elevated production of proteins and humic acids in bound extracellular polymeric substance (EPS) and release of organic matter with high MW fractions in soluble microbial product (SMP) and loosely bound EPS (LB-EPS). Measurement of deposition rate and fluid structure confirmed increased fouling potential of SMP and LB-EPS. γ-Proteobacteria and Ferruginibacter, which can secrete and export EPS, were also found to be abundant in the MBR with WAS fermentation liquid. It is implied that when WAS fermentation liquid was applied, some operational steps to control membrane fouling should be employed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Application of volume-retarded osmosis and low-pressure membrane hybrid process for water reclamation.

Science.gov (United States)

Im, Sung-Ju; Choi, Jungwon; Lee, Jung-Gil; Jeong, Sanghyun; Jang, Am

2018-03-01

A new concept of volume-retarded osmosis and low-pressure membrane (VRO-LPM) hybrid process was developed and evaluated for the first time in this study. Commercially available forward osmosis (FO) and ultrafiltration (UF) membranes were employed in a VRO-LPM hybrid process to overcome energy limitations of draw solution (DS) regeneration and production of permeate in the FO process. To evaluate its feasibility as a water reclamation process, and to optimize the operational conditions, cross-flow FO and dead-end mode UF processes were individually evaluated. For the FO process, a DS concentration of 0.15 g mL -1 of polysulfonate styrene (PSS) was determined to be optimal, having a high flux with a low reverse salt flux. The UF membrane with a molecular weight cut-off of 1 kDa was chosen for its high PSS rejection in the LPM process. As a single process, UF (LPM) exhibited a higher flux than FO, but this could be controlled by adjusting the effective membrane area of the FO and UF membranes in the VRO-LPM system. The VRO-LPM hybrid process only required a circulation pump for the FO process. This led to a decrease in the specific energy consumption of the VRO-LPM process for potable water production, that was similar to the single FO process. Therefore, the newly developed VRO-LPM hybrid process, with an appropriate DS selection, can be used as an energy efficient water production method, and can outperform conventional water reclamation processes. Copyright © 2017 Elsevier Ltd. All rights reserved.

Application of volume-retarded osmosis and low-pressure membrane hybrid process for water reclamation

KAUST Repository

Im, Sung-Ju; Choi, Jungwon; Lee, Jung Gil; Jeong, Sanghyun; Jang, Am

2017-01-01

A new concept of volume-retarded osmosis and low-pressure membrane (VRO-LPM) hybrid process was developed and evaluated for the first time in this study. Commercially available forward osmosis (FO) and ultrafiltration (UF) membranes were employed in a VRO-LPM hybrid process to overcome energy limitations of draw solution (DS) regeneration and production of permeate in the FO process. To evaluate its feasibility as a water reclamation process, and to optimize the operational conditions, cross-flow FO and dead-end mode UF processes were individually evaluated. For the FO process, a DS concentration of 0.15 g mL−1 of polysulfonate styrene (PSS) was determined to be optimal, having a high flux with a low reverse salt flux. The UF membrane with a molecular weight cut-off of 1 kDa was chosen for its high PSS rejection in the LPM process. As a single process, UF (LPM) exhibited a higher flux than FO, but this could be controlled by adjusting the effective membrane area of the FO and UF membranes in the VRO-LPM system. The VRO-LPM hybrid process only required a circulation pump for the FO process. This led to a decrease in the specific energy consumption of the VRO-LPM process for potable water production, that was similar to the single FO process. Therefore, the newly developed VRO-LPM hybrid process, with an appropriate DS selection, can be used as an energy efficient water production method, and can outperform conventional water reclamation processes.

Application of volume-retarded osmosis and low-pressure membrane hybrid process for water reclamation

KAUST Repository

Im, Sung-Ju

2017-11-15

A new concept of volume-retarded osmosis and low-pressure membrane (VRO-LPM) hybrid process was developed and evaluated for the first time in this study. Commercially available forward osmosis (FO) and ultrafiltration (UF) membranes were employed in a VRO-LPM hybrid process to overcome energy limitations of draw solution (DS) regeneration and production of permeate in the FO process. To evaluate its feasibility as a water reclamation process, and to optimize the operational conditions, cross-flow FO and dead-end mode UF processes were individually evaluated. For the FO process, a DS concentration of 0.15 g mL−1 of polysulfonate styrene (PSS) was determined to be optimal, having a high flux with a low reverse salt flux. The UF membrane with a molecular weight cut-off of 1 kDa was chosen for its high PSS rejection in the LPM process. As a single process, UF (LPM) exhibited a higher flux than FO, but this could be controlled by adjusting the effective membrane area of the FO and UF membranes in the VRO-LPM system. The VRO-LPM hybrid process only required a circulation pump for the FO process. This led to a decrease in the specific energy consumption of the VRO-LPM process for potable water production, that was similar to the single FO process. Therefore, the newly developed VRO-LPM hybrid process, with an appropriate DS selection, can be used as an energy efficient water production method, and can outperform conventional water reclamation processes.

Acid extraction by supported liquid membranes containing basic carriers

International Nuclear Information System (INIS)

Danesi, P.R.; Cianetti, C.; Horwitz, E.P.

1983-01-01

The extraction of HNO 3 (nitric acid) from aqueous solutions by permeation through a number of supported liquid membranes containing basic carriers dissolved in diethylbenzene has been studied. The results have shown that the best permeations are obtained with long chain aliphatic amines (TLA, Primene JM-T) followed by TOPO (trioctylphosphine oxide) and then by other monofunctional and bifunctional organophosphorous basic carriers. The influence of an aliphatic diluent on the permeability of HNO 3 through a supported liquid membrane containing TLA as carrier was also investigated. In this case the permeability to HNO 3 decreases as a result of the lower diffusion coefficient of the acid-carrier complex in the more vicous aliphatic solvent. 4 figures

Use of liquid membranes for treatment of nuclear wastes

International Nuclear Information System (INIS)

Dozol, J.F.

1988-01-01

The reprocessing operations produce liquid wastes in which the main components are nitric acid and sodium nitrate. The goal of the experiments is to separate trace amounts of radioactive elements from these acidic and high sodium nitrate content solutions. CMPO, a neutral bifunctional organophosphorus compound, and crown compounds (DC18 C6 - B21 C7) are able to extract respectively actinides, strontium and cesium from these high salinity solutions. The supported liquid membrane (SLM) render the use of expensive tailor-made extractant molecules like CMPO or crown ethers possible. The results obtained for the extraction of actinides and strontium are promising, but research must now be oriented towards improving the stability of the membrane

Surface modification of poly(vinylidene fluoride) hollow fibre membranes for biogas purification in a gas-liquid membrane contactor system.

Science.gov (United States)

Jin, Pengrui; Huang, Chuan; Li, Jiaxiang; Shen, Yadong; Wang, Liao

2017-11-01

The wetting of hollow fibre membranes decreases the performance of the liquid-gas membrane contactor for CO 2 capture in biogas upgrading. To solve this problem, in this work, a poly(vinylidene fluoride) (PVDF) hollow fibre membrane for a liquid-gas membrane contactor was coated with a superhydrophobic layer composed of a combination of hydrophobic SiO 2 nanoparticles and polydimethylsiloxane (PDMS) by the method of spray deposition. A rough layer of SiO 2 deposited on the PVDF membrane resulted in an enhanced surface hydrophobicity. The surface structure of the pristine PVDF significantly affected the homogeneity of the generated SiO 2 layer. A uniform surface coating on the PVDF upper layer resulted from the presence of micrometre and nanometre-sized roughness on the surface of the PVDF membrane, which was achieved with a SiO 2 concentration of 4.44 mg ml -1 (0.2 g/45 ml) in the coating solution. As a result, the water contact angle of the modified surface was recorded as 155 ± 3°, which is higher than that of the pristine surface. The high contact angle is advantageous for reducing the wetting of the membrane. Additional mass transfer resistance was introduced by the superhydrophobic layer. In addition, continuous CO 2 absorption tests were carried out in original and modified PVDF hollow fibre membrane contactors, using monoethanolamine (MEA) solution as the absorbent. A long-term stability test revealed that the modified PVDF hollow fibre membrane contactor was able to outperform the original membrane contactor and demonstrated outstanding long-term stability, suggesting that spray deposition is a promising approach to obtain superhydrophobic PVDF membranes for liquid-gas membrane absorption.

Super liquid-repellent gas membranes for carbon dioxide capture and heart-lung machines.

Science.gov (United States)

Paven, Maxime; Papadopoulos, Periklis; Schöttler, Susanne; Deng, Xu; Mailänder, Volker; Vollmer, Doris; Butt, Hans-Jürgen

2013-01-01

In a gas membrane, gas is transferred between a liquid and a gas through a microporous membrane. The main challenge is to achieve a high gas transfer while preventing wetting and clogging. With respect to the oxygenation of blood, haemocompatibility is also required. Here we coat macroporous meshes with a superamphiphobic-or liquid repellent-layer to meet this challenge. The superamphiphobic layer consists of a fractal-like network of fluorinated silicon oxide nanospheres; gas trapped between the nanospheres keeps the liquid from contacting the wall of the membrane. We demonstrate the capabilities of the membrane by capturing carbon dioxide gas into a basic aqueous solution and in addition use it to oxygenate blood. Usually, blood tends to clog membranes because of the abundance of blood cells, platelets, proteins and lipids. We show that human blood stored in a superamphiphobic well for 24 h can be poured off without leaving cells or adsorbed protein behind.

Magnetic properties of the magnetic hybrid membranes based on various polymer matrices and inorganic fillers

International Nuclear Information System (INIS)

Rybak, Aleksandra; Kaszuwara, Waldemar

2015-01-01

Magnetic hybrid membranes based on ethylcellulose (EC), poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) and various magnetic praseodymium and neodymium powder microparticles as fillers were obtained. Permeability, diffusion and sorption coefficients of O 2 , N 2 and synthetic air components were estimated for homogeneous and heterogeneous membranes using the Time Lag method based on constant pressure permeation technique. The microstructure studies and the phase analysis of magnetic membranes were also performed using SEM and XRD. The influence of magnetic parameters, like coercivity, remanence and saturation magnetization of created membranes on the gas transport properties was studied. The results showed that their coercivity depended on composition and microstructure of the magnetic powder. On the other hand, remanence and saturation magnetization increased with the increase of the powder addition in the membrane. It was found that the magnetic membrane's gas transport properties were improved with the increase of membrane's remanence, saturation magnetization and magnetic particle filling. The decrease in powder particle size and associated increase of the membrane's coercivity also positively influenced the gas transport and separation properties of investigated membranes. It was observed that the magnetic ethylcellulose and poly(2,6-dimethyl-1,4-phenylene oxide) membranes had higher gas permeability, while their permselectivity and solubility coefficient values were rather maintained or slightly increased. The results also showed that the magnetic powder content enhanced significantly gas diffusivity in EC and PPO membranes. It was also analyzed the dependence of the drift coefficient w on the magnetic parameters of investigated membranes. The correlation between the membrane selectivity, permeability and magnetic properties with their XRD characteristics was stated. - Highlights: • Membrane's production consisting of EC or PPO polymers and

Magnetic properties of the magnetic hybrid membranes based on various polymer matrices and inorganic fillers

Energy Technology Data Exchange (ETDEWEB)

Rybak, Aleksandra, E-mail: Aleksandra.Rybak@polsl.pl [Department of Physical Chemistry and Technology of Polymers, Faculty of Chemistry, Silesian University of Technology, Strzody 9, 44-100 Gliwice (Poland); Kaszuwara, Waldemar [Faculty of Materials Science and Engineering, Warsaw University of Technology, Woloska 141, 02-507 Warszawa (Poland)

2015-11-05

Magnetic hybrid membranes based on ethylcellulose (EC), poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) and various magnetic praseodymium and neodymium powder microparticles as fillers were obtained. Permeability, diffusion and sorption coefficients of O{sub 2}, N{sub 2} and synthetic air components were estimated for homogeneous and heterogeneous membranes using the Time Lag method based on constant pressure permeation technique. The microstructure studies and the phase analysis of magnetic membranes were also performed using SEM and XRD. The influence of magnetic parameters, like coercivity, remanence and saturation magnetization of created membranes on the gas transport properties was studied. The results showed that their coercivity depended on composition and microstructure of the magnetic powder. On the other hand, remanence and saturation magnetization increased with the increase of the powder addition in the membrane. It was found that the magnetic membrane's gas transport properties were improved with the increase of membrane's remanence, saturation magnetization and magnetic particle filling. The decrease in powder particle size and associated increase of the membrane's coercivity also positively influenced the gas transport and separation properties of investigated membranes. It was observed that the magnetic ethylcellulose and poly(2,6-dimethyl-1,4-phenylene oxide) membranes had higher gas permeability, while their permselectivity and solubility coefficient values were rather maintained or slightly increased. The results also showed that the magnetic powder content enhanced significantly gas diffusivity in EC and PPO membranes. It was also analyzed the dependence of the drift coefficient w on the magnetic parameters of investigated membranes. The correlation between the membrane selectivity, permeability and magnetic properties with their XRD characteristics was stated. - Highlights: • Membrane's production consisting of EC or PPO

Liquid membranes: an emerging area in separation science

International Nuclear Information System (INIS)

Mohapatra, P.K.; Manchanda, V.K.

2010-01-01

Full text: With the ever increasing energy demands, nuclear energy is poised to make a significant contribution as one of the major clean energy resources. The public acceptability of the nuclear energy programme, however, depends largely on the management of radioactive waste by mitigating its long term adverse impact on the environment. Separation of long-lived radionuclides such as actinides and fission products from high level radioactive waste is a challenging task for the chemists involved at the back end of the nuclear fuel cycle. Amongst the various separation techniques, liquid membrane based separation methods are becoming increasingly popular due to factors such as ligand economy, high efficiency and low power consumption. Techniques such as emulsion liquid membrane (ELM) and hollow fibre supported liquid membrane (HFSLM) methods are reported to be more efficient than the solvent extraction based separation methods which have limitations of emulsion/third phase or crud formation. HFSLM technique offers the advantages of active transport, possible usage of exotic carriers and easy scale-up. For the past few years, Radiochemistry Division has been actively involved in the development of HFSLM separation processes for actinide partitioning, lanthanide/actinide separation, Sr/Y separation as well as recovery of radio-cesium from nuclear waste solutions. Similarly, ELM has major advantages of fast processing and large volume reduction factors. This lecture will give an overview of the HFSLM and ELM work carried out at Radiochemistry Division, Bhabha Atomic Research Centre, Mumbai

Modelling of a tubular membrane contactor for pre-combustion CO2 capture using ionic liquids: Influence of the membrane configuration, absorbent properties and operation parameters

Directory of Open Access Journals (Sweden)

Zhongde Dai

2016-10-01

Full Text Available A membrane contactor using ionic liquids (ILs as solvent for pre-combustion capture CO2 at elevated temperature (303–393 K and pressure (20 bar has been studied using mathematic model in the present work. A comprehensive two-dimensional (2D mass-transfer model was developed based on finite element method. The effects of liquid properties, membrane configurations, as well as operation parameters on the CO2 removal efficiency were systematically studied. The simulation results show that CO2 can be effectively removed in this process. In addition, it is found that the liquid phase mass transfer dominated the overall mass transfer. Membranes with high porosity and small thickness could apparently reduce the membrane resistance and thus increase the separation efficiency. On the other hand, the membrane diameter and membrane length have a relatively small influence on separation performance within the operation range. Keywords: CO2 capture, Pre-combustion, Membrane contactor, Ionic liquids, Modelling

Mass transfer rate through liquid membranes: interfacial chemical reactions and diffusion as simultaneous permeability controlling factors

International Nuclear Information System (INIS)

Danesi, P.R.; Horwitz, E.P.; Vandegrift, G.F.; Chiarizia, R.

1981-01-01

Equations describing the permeability of a liquid membrane to metal cations have been derived taking into account aqueous diffusion, membrane diffusion, and interfacial chemical reactions as simultaneous permeability controlling factors. Diffusion and chemical reactions have been coupled by a simple model analogous to the one previously described by us to represent liquid-liquid extraction kinetics. The derived equations, which make use of experimentally determined interfacial reaction mechanisms, qualitatively fit unexplained literature data regarding Cu 2+ transfer through liquid membranes. Their use to predict and optimize membrane permeability in practical separation processes by setting the appropriate concentration of the membrane carrier [LIX 64 (General Mills), a commercial β-hydroxy-oxime] and the pH of the aqueous copper feed solution is briefly discussed. 4 figures

Studies on soy protein isolate/polyvinyl alcohol hybrid nanofiber membranes as multi-functional eco-friendly filtration materials

International Nuclear Information System (INIS)

Fang, Qun; Zhu, Ming; Yu, Siruo; Sui, Gang; Yang, Xiaoping

2016-01-01

Highlights: • Biodegradable filtration membranes were prepared. • Polar groups in the membrane surface helped capture fine particles. • Loading filtration efficiency can reach 99.99% in the case of small pressure drop. • Filtration membrane showed antimicrobial activity to Escherichia coli. - Abstract: A biodegradable and multifunctional air filtration membrane was prepared by electrospinning of soy protein isolate (SPI)/polyvinyl alcohol (PVA) system in this paper. The optimized SPI/PVA proportion in the spinning solution was determined according to the analyses of microstructure, surface chemical characteristic and mechanical property of the hybrid nanofiber membranes. Under the preferred preparation condition, two kinds of polymer materials displayed a good compatibility in the hybrid nanofibers, and a large number of polar groups existed in the membrane surface. The loading filtration efficiency of the nanofiber membrane with optimal material ratio and areal density can reach 99.99% after test of 30 min for fine particles smaller than 2.5 μm in the case of small pressure drop. Besides, this kind of filtration membrane showed an antimicrobial activity to Escherichia coli in the study. The SPI/PVA hybrid nanofiber membrane with proper material composition and microstructure can be used as a new type of high performance eco-friendly filtration materials.

Studies on soy protein isolate/polyvinyl alcohol hybrid nanofiber membranes as multi-functional eco-friendly filtration materials

Energy Technology Data Exchange (ETDEWEB)

Fang, Qun; Zhu, Ming; Yu, Siruo; Sui, Gang, E-mail: suigang@mail.buct.edu.cn; Yang, Xiaoping

2016-12-15

Highlights: • Biodegradable filtration membranes were prepared. • Polar groups in the membrane surface helped capture fine particles. • Loading filtration efficiency can reach 99.99% in the case of small pressure drop. • Filtration membrane showed antimicrobial activity to Escherichia coli. - Abstract: A biodegradable and multifunctional air filtration membrane was prepared by electrospinning of soy protein isolate (SPI)/polyvinyl alcohol (PVA) system in this paper. The optimized SPI/PVA proportion in the spinning solution was determined according to the analyses of microstructure, surface chemical characteristic and mechanical property of the hybrid nanofiber membranes. Under the preferred preparation condition, two kinds of polymer materials displayed a good compatibility in the hybrid nanofibers, and a large number of polar groups existed in the membrane surface. The loading filtration efficiency of the nanofiber membrane with optimal material ratio and areal density can reach 99.99% after test of 30 min for fine particles smaller than 2.5 μm in the case of small pressure drop. Besides, this kind of filtration membrane showed an antimicrobial activity to Escherichia coli in the study. The SPI/PVA hybrid nanofiber membrane with proper material composition and microstructure can be used as a new type of high performance eco-friendly filtration materials.

Two-dimensional materials for novel liquid separation membranes

Science.gov (United States)

Ying, Yulong; Yang, Yefeng; Ying, Wen; Peng, Xinsheng

2016-08-01

Demand for a perfect molecular-level separation membrane with ultrafast permeation and a robust mechanical property for any kind of species to be blocked in water purification and desalination is urgent. In recent years, due to their intrinsic characteristics, such as a unique mono-atom thick structure, outstanding mechanical strength and excellent flexibility, as well as facile and large-scale production, graphene and its large family of two-dimensional (2D) materials are regarded as ideal membrane materials for ultrafast molecular separation. A perfect separation membrane should be as thin as possible to maximize its flux, mechanically robust and without failure even if under high loading pressure, and have a narrow nanochannel size distribution to guarantee its selectivity. The latest breakthrough in 2D material-based membranes will be reviewed both in theories and experiments, including their current state-of-the-art fabrication, structure design, simulation and applications. Special attention will be focused on the designs and strategies employed to control microstructures to enhance permeation and selectivity for liquid separation. In addition, critical views on the separation mechanism within two-dimensional material-based membranes will be provided based on a discussion of the effects of intrinsic defects during growth, predefined nanopores and nanochannels during subsequent fabrication processes, the interlayer spacing of stacking 2D material flakes and the surface charge or functional groups. Furthermore, we will summarize the significant progress of these 2D material-based membranes for liquid separation in nanofiltration/ultrafiltration and pervaporation. Lastly, we will recall issues requiring attention, and discuss existing questionable conclusions in some articles and emerging challenges. This review will serve as a valuable platform to provide a compact source of relevant and timely information about the development of 2D material-based membranes as

Two-dimensional materials for novel liquid separation membranes.

Science.gov (United States)

Ying, Yulong; Yang, Yefeng; Ying, Wen; Peng, Xinsheng

2016-08-19

Demand for a perfect molecular-level separation membrane with ultrafast permeation and a robust mechanical property for any kind of species to be blocked in water purification and desalination is urgent. In recent years, due to their intrinsic characteristics, such as a unique mono-atom thick structure, outstanding mechanical strength and excellent flexibility, as well as facile and large-scale production, graphene and its large family of two-dimensional (2D) materials are regarded as ideal membrane materials for ultrafast molecular separation. A perfect separation membrane should be as thin as possible to maximize its flux, mechanically robust and without failure even if under high loading pressure, and have a narrow nanochannel size distribution to guarantee its selectivity. The latest breakthrough in 2D material-based membranes will be reviewed both in theories and experiments, including their current state-of-the-art fabrication, structure design, simulation and applications. Special attention will be focused on the designs and strategies employed to control microstructures to enhance permeation and selectivity for liquid separation. In addition, critical views on the separation mechanism within two-dimensional material-based membranes will be provided based on a discussion of the effects of intrinsic defects during growth, predefined nanopores and nanochannels during subsequent fabrication processes, the interlayer spacing of stacking 2D material flakes and the surface charge or functional groups. Furthermore, we will summarize the significant progress of these 2D material-based membranes for liquid separation in nanofiltration/ultrafiltration and pervaporation. Lastly, we will recall issues requiring attention, and discuss existing questionable conclusions in some articles and emerging challenges. This review will serve as a valuable platform to provide a compact source of relevant and timely information about the development of 2D material-based membranes as

Hybrid silica luminescent materials based on lanthanide-containing lyotropic liquid crystal with polarized emission

Energy Technology Data Exchange (ETDEWEB)

Selivanova, N.M., E-mail: natsel@mail.ru [Kazan National Research Technological University, 68 Karl Marx Str., Kazan 420015 (Russian Federation); Vandyukov, A.E.; Gubaidullin, A.T. [A.E. Arbuzov Institute of Organic and Physical Chemistry of the Kazan Scientific Center of the Russian Academy of Sciences, 8 Acad. Arbuzov Str., Kazan 420088 (Russian Federation); Galyametdinov, Y.G. [Kazan National Research Technological University, 68 Karl Marx Str., Kazan 420015 (Russian Federation)

2014-11-14

This paper represents the template method for synthesis of hybrid silica films based on Ln-containing lyotropic liquid crystal and characterized by efficient luminescence. Luminescence films were prepared in situ by the sol–gel processes. Lyotropic liquid crystal (LLC) mesophases C{sub 12}H{sub 25}O(CH{sub 2}CH{sub 2}O){sub 10}H/Ln(NO{sub 3}){sub 3}·6H{sub 2}O/H{sub 2}O containing Ln (III) ions (Dy, Tb, Eu) were used as template. Polarized optical microscopy, X-ray powder diffraction, and FT-IR-spectroscopy were used for characterization of liquid crystal mesophases and hybrid films. The morphology of composite films was studied by the atomic force microscopy method (AFM). The optical properties of the resulting materials were evaluated. It was found that hybrid silica films demonstrate significant increase of their lifetime in comparison with an LLC system. New effects of linearly polarized emission revealed for Ln-containing hybrid silica films. Polarization in lanthanide-containing hybrid composites indicates that silica precursor causes orientation of emitting ions. - Highlights: • We suggest a new simple approach for creating luminescence hybrid silica films. • Ln-containing hybrid silica films demonstrate yellow, green and red emissions. • Tb(III)-containing hybrid film have a high lifetime. • We report effects of linearly polarized emission in hybrid film.

Membrane treatment of liquid wastes from radiological decontamination operations.

Science.gov (United States)

Svittsov, A A; Khubetsov, S B; Volchek, K

2011-01-01

The paper focuses on the evaluation of membrane filtration for the treatment of liquid radioactive streams generated in area decontamination operations. In this work, semi-permeable membranes were demonstrated to be effective reducing the volume of wastewater containing cesium and cobalt by two orders of a magnitude. The efficiency of membrane separation was enhanced by employing additives that enlarged the size of target radionuclide species and improved their rejection by the membranes. This was achieved by chelation with synthetic water-soluble polymers and by adsorption on micro particles of adsorbent coupled with micelle formation. The effect of wastewater composition and that of the radionuclide-binding additives on the volume reduction was investigated. Membrane treatment is expected to help simplify further processing and decrease disposal costs.

Study of cross-linking reactions induced by gamma rays in hybrid membranes of Bisphenol-A-Polysulfone and precipitated silica

International Nuclear Information System (INIS)

Furtado Filho, Acacio Antonio M.; Gomes, Ailton de S.; Lopes, Lea; Benzi, Marcia R.

2011-01-01

In this work the bisphenol-A-polysulfone (PSF) was sulfonated using trimethyl silyl chlorosulfonate [(CH 3 ) 3 SiSO 3 Cl] as a mild sulfonating agent in a homogeneous solution of dichloroethane. The sulfonation reaction was confirmed by acid-base titration and FTIR-spectroscopy analysis. The hybrid membranes were obtained by casting the sulfonated bisphenol-A-polysulfone (SPSF) and precipitated silica Tixosil R 333 solutions in N-N-dimethylacetamide. Cross-linking in the hybrid membranes was obtained by irradiation, with doses ranging from 5 to 30 kGy using gamma ray from a 60 Co source. The water uptake and the swelling of the membranes were estimated by measuring the change in weight between dry and wet conditions. The conductivity of the membranes in acid form was measured with the ac impedance technique using a PGSTAT30 frequency response analyzer. The hybrid cross-linked membranes have conductivity close to 10-1 S.cm -1 at 100% RH and 80 deg C. Electrochemical performances, thermo-mechanical stability and low cost make this cross-linked SPSF hybrid membrane an attractive material for fuel cells using a proton exchange membrane. (author)

Proton-conducting ionic liquid-based proton exchange membrane fuel cell membranes: The key role of ionomer-ionic liquid interaction

Energy Technology Data Exchange (ETDEWEB)

Martinez, Mathieu; Cointeaux, Laure; Iojoiu, Cristina; Lepretre, Jean-Claude; Sanchez, Jean-Yves [LEPMI, UMR 5631, CNRS-INP-UJF, PHELMA-Campus, BP.75, 1130 rue de la Piscine, 38402 Saint-Martin-d' Heres Cedex (France); Molmeret, Yannick; El Kissi, Nadia [Laboratoire de Rheologie, UMR 5520 CNRS-INPG-UJF, ENSHMG, BP 53, 38041 Grenoble (France); Judeinstein, Patrick [Institut de Chimie Moleculaire et des Materiaux d' Orsay (UMR 8182), Batiment 410, Universite Paris-Sud 11, 91405 Orsay Cedex (France)

2010-09-15

The paper deals with the synthesis and characterisation of proton-conducting ionic liquids (PCILs) and their polymer electrolytes obtained by blending modified Nafion membranes with different concentrations of PCILs. The PCILs are obtained by the neutralization of triethylamine with different organic acids. The first part of the paper studies the influence of acidity and acid structure on PCIL thermal and electrochemical performance, while the second part examines membrane conductivity and reveals it to depend more on PCIL structure than on its intrinsic conductivity. At 130 C, conductivities exceeding 10 mS cm{sup -1} were obtained in fully anhydrous conditions. (author)

Superhydrophobic hybrid membranes by grafting arc-like macromolecular bridges on graphene sheets: Synthesis, characterization and properties

Science.gov (United States)

Mo, Zhao-Hua; Luo, Zheng; Huang, Qiang; Deng, Jian-Ping; Wu, Yi-Xian

2018-05-01

Grafting single end-tethered polymer chains on the surface of graphene is a conventional way to modify the surface properties of graphene oxide. However, grafting arc-like macromolecular bridges on graphene surfaces has been barely reported. Herein, a novel arc-like polydimethylsiloxane (PDMS) macromolecular bridges grafted graphene sheets (GO-g-Arc PDMS) was successfully synthesized via a confined interface reaction at 90 °C. Both the hydrophilic α- and ω-amino groups of linear hydrophobic NH2-PDMS-NH2 macromolecular chains rapidly reacted with epoxy and carboxyl groups on the surfaces of graphene oxide in water suspension to form arc-like PDMS macromolecular bridges on graphene sheets. The grafting density of arc-like PDMS bridges on graphene sheets can reach up to 0.80 mmol g-1 or 1.32 arc-like bridges per nm2 by this confined interface reaction. The water contact angle (WCA) of the hybrid membrane could be increased with increasing both the grafting density and content of covalent arc-like bridges architecture. The superhydrophobic hybrid membrane with a WCA of 153.4° was prepared by grinding of the above arc-like PDMS bridges grafted graphene hybrid, dispersing in ethanol and filtrating by organic filter membrane. This superhydrophobic hybrid membrane shows good self-cleaning and complete oil-water separation properties, which provides potential applications in anticontamination coating and oil-water separation. To the best of our knowledge, this is the first report on the synthesis of functional hybrid membranes by grafting arc-like PDMS macromolecular bridges on graphene sheets via a confined interface reaction.

Liquid membrane process for uranium recovery

International Nuclear Information System (INIS)

Valint, P.L. Jr.

1982-01-01

An improved liquid membrane emulsion extraction process for recovering uranium from a WPPA feed solution containing uranyl cations wherein said feed is contacted with a water-in-oil emulsion which extracts and captures the uranium in the interior aqueous phase thereof, wherein the improvement comprises the presence of an alkane diphosphonic acid uranium complexing agent in the interior phase of the emulsion. This improvement results in greater extraction efficiency

Innovative methods to stabilize liquid membranes for removal of radionuclides from groundwater

Energy Technology Data Exchange (ETDEWEB)

Lokhandwala, K. [Membrane Technology and Research, Inc., Menlo Park, CA (United States)

1997-10-01

In this Phase I Small Business Innovation Research program, Membrane Technology Research, Inc., is developing a stable liquid membrane for extracting uranium and other radionuclides from groundwater. The improved membrane can also be applied to separation of other metal ions from aqueous streams in industrial operations.

Nutrient utilization and oxygen production by Chlorella Vulgaris in a hybrid membrane bioreactor and algal membrane photobioreactor system

KAUST Repository

Najm, Yasmeen Hani Kamal; Jeong, Sanghyun; Leiknes, TorOve

2017-01-01

This work studied oxygen production and nutrient utilization by Chlorella Vulgaris at different organic/inorganic carbon (OC/IC) and ammonium/nitrate (NH4+-N/NO3--N) ratios to design a hybrid aerobic membrane bioreactor (MBR) and membrane photobioreactor (MPBR) system. Specific oxygen production by C. vulgaris was enough to support the MBR if high growth is accomplished. Nearly 100% removal (or utilization) of PO43--P and IC was achieved under all conditions tested. Optimal growth was achieved at mixotrophic carbon conditions (0.353 d-1) and the highest NH4+-N concentration (0.357 d-1), with preferable NH4+-N utilization rather than NO3--N. The results indicate the potential of alternative process designs to treat domestic wastewater by coupling the hybrid MBR - MPBR systems.

Nutrient utilization and oxygen production by Chlorella Vulgaris in a hybrid membrane bioreactor and algal membrane photobioreactor system

KAUST Repository

Najm, Yasmeen Hani Kamal

2017-02-17

This work studied oxygen production and nutrient utilization by Chlorella Vulgaris at different organic/inorganic carbon (OC/IC) and ammonium/nitrate (NH4+-N/NO3--N) ratios to design a hybrid aerobic membrane bioreactor (MBR) and membrane photobioreactor (MPBR) system. Specific oxygen production by C. vulgaris was enough to support the MBR if high growth is accomplished. Nearly 100% removal (or utilization) of PO43--P and IC was achieved under all conditions tested. Optimal growth was achieved at mixotrophic carbon conditions (0.353 d-1) and the highest NH4+-N concentration (0.357 d-1), with preferable NH4+-N utilization rather than NO3--N. The results indicate the potential of alternative process designs to treat domestic wastewater by coupling the hybrid MBR - MPBR systems.

Evaluation of transport properties of nanofiltration membranes exposed to radioactive liquid waste

Energy Technology Data Exchange (ETDEWEB)

Oliveira, Elizabeth E.M.; Barbosa, Celina C.R.; Bastos, Edna T.R., E-mail: eemo@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeira, RJ (Brazil); Afonso, Julio C., E-mail: Julio@iq.ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Quimica. Dept. de Quimica Analitica

2011-07-01

The application of membrane separation processes (PSM) for treatment of radioactive waste requires the selection of a suitable membrane for the treatment of waste, as the membrane will be directly exposed to the radioactive liquid waste, and also exposed to ionizing radiation. The nanofiltration membrane is most suitable for treatment of radioactive waste, since it has high rejection of multivalent ions. Usually the membranes are made of polymers and depending on the composition of the waste, type and dose of radiation absorbed may be changes in the structure of the membrane, resulting in loss of its transport properties. We tested two commercial nanofiltration membranes: NF and SW Dow/Filmtec. The waste liquid used was obtained in the process of conversion of uranium hexafluoride gas to solid uranium dioxide, known as 'carbonated water'. The membranes were characterized as their transport properties (hydraulic permeability, permeate flux and salt rejection) before and after their immersion in the waste for 24 hours. The surface of the membranes was also evaluated by SEM and FTIR. It was observed that in both the porosity of the membrane selective layer was altered, but not the membrane surface charge, which is responsible for the selectivity of the membrane. The NF membranes and SW showed uranium ion rejection of 64% and 55% respectively. (author)

Hollow fiber liquid supported membranes

International Nuclear Information System (INIS)

Violante, V.

1987-01-01

The hollow fiber system are well known and developed in the scientific literature because of their applicability in the process separation units. The authors approach to a mathematical model for a particular hollow fiber system, usin liquid membranes. The model has been developed in order to obtain a suitable tool for a sensitivy analysis and for a scaling-up. This kind of investigation is very usefull from an engineering point of view, to get a spread range of information to build up a pilot plant from the laboratory scale

Transport of Liquid Phase Organic Solutes in Liquid Crystalline Membranes

OpenAIRE

Han, Sangil

2010-01-01

Porous cellulose nitrate membranes were impregnated with 8CB and PCH5 LCs (liquid crystals) and separations of solutes dissolved in aqueous phases were performed while monitoring solute concentration via UV-VIS spectrometry. The diffusing organic solutes, which consist of one aromatic ring and various functional groups, were selected to exclude molecular size effects on the diffusion and sorption. We studied the effects on solute transport of solute intra-molecular hydrogen bonding and so...

Continual Energy Management System of Proton Exchange Membrane Fuel Cell Hybrid Power Electric Vehicles

Directory of Open Access Journals (Sweden)

Ren Yuan

2016-01-01

Full Text Available Current research status in energy management of Proton Exchange Membrane (PEM fuel cell hybrid power electric vehicles are first described in this paper, and then build the PEMFC/ lithium-ion battery/ ultra-capacitor hybrid system model. The paper analysis the key factors of the continuous power available in PEM fuel cell hybrid power electric vehicle and hybrid power system working status under different driving modes. In the end this paper gives the working flow chart of the hybrid power system and concludes the three items of the system performance analysis.

Manipulating lipid membrane architecture by liquid crystal-analog curvature elasticity (Presentation Recording)

Science.gov (United States)

Lee, Sin-Doo

2015-10-01

Soft matters such as liquid crystals and biological molecules exhibit a variety of interesting physical phenomena as well as new applications. Recently, in mimicking biological systems that have the ability to sense, regulate, grow, react, and regenerate in a highly responsive and self-adaptive manner, the significance of the liquid crystal order in living organisms, for example, a biological membrane possessing the lamellar order, is widely recognized from the viewpoints of physics and chemistry of interfaces and membrane biophysics. Lipid bilayers, resembling cell membranes, provide primary functions for the transport of biological components of ions and molecules in various cellular activities, including vesicle budding and membrane fusion, through lateral organization of the membrane components such as proteins. In this lecture, I will describe how the liquid crystal-analog curvature elasticity of a lipid bilayer plays a critical role in developing a new platform for understanding diverse biological functions at a cellular level. The key concept is to manipulate the local curvature at an interface between a solid substrate and a model membrane. Two representative examples will be demonstrated: one of them is the topographic control of lipid rafts in a combinatorial array where the ligand-receptor binding event occurs and the other concerns the reconstitution of a ring-type lipid raft in bud-mimicking architecture within the framework of the curvature elasticity.

The potential of hybrid forward osmosis membrane bioreactor (FOMBR) processes in achieving high throughput treatment of municipal wastewater with enhanced phosphorus recovery.

Science.gov (United States)

Qiu, Guanglei; Zhang, Sui; Srinivasa Raghavan, Divya Shankari; Das, Subhabrata; Ting, Yen-Peng

2016-11-15

Extensive research in recent years has explored numerous new features in the forward osmosis membrane bioreactor (FOMBR) process. However, there is an aspect, which is revolutionary but not yet been investigated. In FOMBR, FO membrane shows high rejection for a wide range of soluble contaminants. As a result, hydraulic retention time (HRT) does not correctly reflect the nominal retention of these dissolved contaminants in the bioreactor. This decoupling of contaminants retention time (CRT, i.e. the nominal retention of the dissolved contaminants) from HRT endows FOMBR a potential in significantly reducing the HRT for wastewater treatment. In this work, we report our results in this unexplored treatment potential. Using real municipal wastewater as feed, both a hybrid microfiltration-forward osmosis membrane bioreactor (MF-FOMBR) and a newly developed hybrid biofilm-forward osmosis membrane bioreactor (BF-FOMBR) achieved high removal of organic matter and nitrogen under HRT of down to 2.0 h, with significantly enhanced phosphorus recovery capacities. In the BF-FOMBR, the used of fixed bed biofilm not only obviated the need of additional solid/liquid separation (e.g. MF) to extract the side-stream for salt accumulation control and phosphorus recovery, but effectively quarantined the biomass from the FO membrane. The absence of MF in the side-stream further allowed suspended growth to be continuously removed from the system, which produced a selection pressure for the predominance of attached growth. As a result, a significant reduction in FO membrane fouling (by 24.7-54.5%) was achieved in the BF-FOMBR due to substantially reduced bacteria deposition and colonization. Copyright © 2016 Elsevier Ltd. All rights reserved.

Surface modification of polyamide reverse osmosis membrane with organic-inorganic hybrid material for antifouling

Science.gov (United States)

Zhang, Yang; Wan, Ying; Pan, Guoyuan; Yan, Hao; Yao, Xuerong; Shi, Hongwei; Tang, Yujing; Wei, Xiangrong; Liu, Yiqun

2018-03-01

A series of thin-film composite reverse osmosis membranes based on polyamide have been modified by coating the polyvinyl alcohol and 3-mercaptopropyltriethoxysilane aqueous solution prepared by a sol-gel process on the membrane surface, followed by thermal crosslinking treatment. In order to improve the hydrophilicity of the modified TFC membranes, the membranes were then immersed into H2O2 aqueous solution to convert -SH into -SO3H. The resulting TFC membranes were characterized by SEM, AFM, ATR-FTIR, streaming potential, XPS as well as static contact angle. After surface modification with the organic-inorganic hybrid material, the TFC membranes show increased NaCl rejection and decreased water flux with increasing 3-mercaptopropyltrimethoxysilane content in coating solution. The optimal modification membrane (PA-SMPTES-0.8) exhibits a NaCl rejection of 99.29%, higher than that (97.20%) of the virgin PA membrane, and a comparable water flux to virgin PA membrane (41.7 L/m2 h vs 47.9 L/m2 h). More importantly, PA-SMPTES-0.8 membrane shows much more improved fouling resistance to BSA than virgin PA and PVA modified PA (PA-PVA-1.0) membranes. PA-SMPTES-0.8 membrane loses about 13% of the initial flux after BSA fouling for 12 h, which is lower than that of virgin PA and PA-PVA-1.0 membranes (42% and 18%). Furthermore, the flux recovery of PA-SMPTES-0.8 membrane reaches 94% after cleaning. Thus the TFC membranes modified by this organic-inorganic hybrid technology show potential applications as antifouling RO membrane for desalination and purification.

Electrokinetic migration across artificial liquid membranes. New concept for rapid sample preparation of biological fluids.

Science.gov (United States)

Pedersen-Bjergaard, Stig; Rasmussen, Knut Einar

2006-03-24

Basic drug substances were transported across a thin artificial organic liquid membrane by the application of 300 V d.c. From a 300 microl aqueous donor compartment (containing 10 mM HCl), the drugs migrated through a 200 microm artificial liquid membrane of 2-nitrophenyl octyl ether immobilized in the pores of a polypropylene hollow fiber, and into a 30 microl aqueous acceptor solution of 10 mM HCl inside the lumen of the hollow fiber. The transport was forced by an electrical potential difference sustained over the liquid membrane, resulting in electrokinetic migration of drug substances from the donor compartment to the acceptor solution. Within 5 min of operation at 300 V, pethidine, nortriptyline, methadone, haloperidol, and loperamide were extracted with recoveries in the range 70-79%, which corresponded to enrichments in the range 7.0-7.9. The chemical composition of the organic liquid membrane strongly affected the permeability, and may serve as an efficient tool for controlling the transport selectivity. Water samples, human plasma, and human urine were successfully processed, and in light of the present report, electrokinetic migration across thin artificial liquid membranes may be an interesting tool for future isolation within chemical analysis.

Can macular xanthophylls replace cholesterol in formation of the liquid-ordered phase in lipid-bilayer membranes?

Science.gov (United States)

Subczynski, Witold K; Wisniewska-Becker, Anna; Widomska, Justyna

2012-01-01

Lateral organization of membranes made from binary mixtures of dimyristoylphosphatidylcholine (DMPC) or dipalmitoylphosphatidylcholine (DPPC) and macular xanthophylls (lutein or zeaxanthin) was investigated using the saturation-recovery (SR) EPR spin-labeling discrimination by oxygen transport (DOT) method in which the bimolecular collision rate of molecular oxygen with the nitroxide spin label is measured. This work was undertaken to examine whether or not lutein and zeaxanthin, macular xanthophylls that parallel cholesterol in its function as a regulator of both membrane fluidity and hydrophobicity, can parallel other structural functions of cholesterol, including formation of the liquid-ordered phase in membranes. The DOT method permits discrimination of different membrane phases when the collision rates (oxygen transport parameter) differ in these phases. Additionally, membrane phases can be characterized by the oxygen transport parameter in situ without the need for separation, which provides information about the dynamics of each phase. In gel-phase membranes, two coexisting phases were discriminated in the presence of macular xanthophylls - namely, the liquid-ordered-like and solid-ordered-like phases. However, in fluid-phase membranes, xanthophylls only induce the solitary liquid-ordered-like phase, while at similar concentrations, cholesterol induces coexisting liquid-ordered and liquid-disordered phases. No significant differences between the effects of lutein and zeaxanthin were found.

Emulsion liquid membrane for selective extraction of bismuth from nitrate medium

International Nuclear Information System (INIS)

Mokhtari, Bahram; Pourabdollah, Kobra

2013-01-01

The novelty of this work is the selective extraction of bismuth ions from nitrate medium by emulsion liquid membrane. Di(2-ethylhexyl)phosphoric acid was used as extractant of bismuth ions from nitrate medium by emulsion liquid membrane, and Triton X-100 was used as the biodegradable surfactant in n-pentanol n-pentanol bulk membrane. The extraction of bismuth ions was evaluated by the yield of extraction. The experimental parameters were evaluated and were optimized. They included the ratio of di(2-ethylhexyl)phosphoric acid concentration to the concentration of /Triton X-100 concentration (1.0 : 0.5% w/w), nature of diluents (n-pentanol), nature and concentration of the stripping solution (sulfuric acid, 0.5M), stirring speed (1,800 rpm) and equilibrium time of extraction (20min), initial feed solution of bismuth (350 ppm) and the volume ratio of the internal stripping phase to the membrane phase (14 times). The experimental parameters of kinetic extraction revealed that the bismuth ions were extracted at 100% 97%

Emulsion liquid membrane for selective extraction of bismuth from nitrate medium

Energy Technology Data Exchange (ETDEWEB)

Mokhtari, Bahram; Pourabdollah, Kobra [Islamic Azad University, Shahreza (Iran, Islamic Republic of)

2013-07-15

The novelty of this work is the selective extraction of bismuth ions from nitrate medium by emulsion liquid membrane. Di(2-ethylhexyl)phosphoric acid was used as extractant of bismuth ions from nitrate medium by emulsion liquid membrane, and Triton X-100 was used as the biodegradable surfactant in n-pentanol n-pentanol bulk membrane. The extraction of bismuth ions was evaluated by the yield of extraction. The experimental parameters were evaluated and were optimized. They included the ratio of di(2-ethylhexyl)phosphoric acid concentration to the concentration of /Triton X-100 concentration (1.0 : 0.5% w/w), nature of diluents (n-pentanol), nature and concentration of the stripping solution (sulfuric acid, 0.5M), stirring speed (1,800 rpm) and equilibrium time of extraction (20min), initial feed solution of bismuth (350 ppm) and the volume ratio of the internal stripping phase to the membrane phase (14 times). The experimental parameters of kinetic extraction revealed that the bismuth ions were extracted at 100% 97%.

Liquid nitrogen cryotherapy for lip mucous membrane venous malformation in infants.

Science.gov (United States)

Zhang, Da-Ming; Wang, You-Yuan; Lin, Zhao-Yu; Yang, Zhao-Hui; Chen, Wei-Liang

2015-03-01

Lip mucous membrane venous malformations are common benign lesions in infants. This clinical study evaluates the efficacy and safety of liquid nitrogen cryotherapy used to treat this condition. A total of 84 pediatric patients undergoing liquid nitrogen cryotherapy for venous malformations involving the lips were reviewed, with 45 males and 39 females treated. The overall median age at mucous membrane venous malformation diagnosis was 5.6 months (range 2-18 months). The venous malformations involved the vermilion of the lower lip in 44 cases, the vermilion of the upper lip in 31 cases, and both vermilions in 9 cases. No complications due to anesthesia occurred. After a follow-up period of 2-38 months (mean 25 months), 65 lesions (77.4 %) were completely involuted, 14 lesions (16.7 %) were mostly involuted, and 5 lesions (5.9 %) were partially involuted; no lesions showed a minor amount of involution. Liquid nitrogen cryotherapy is an effective, simple, and safe management tool for mucous membrane venous malformations of the lip in infants.

Development of an energy-saving anaerobic hybrid membrane bioreactors for 2-chlorophenol-contained wastewater treatment.

Science.gov (United States)

Wang, Yun-Kun; Pan, Xin-Rong; Sheng, Guo-Ping; Li, Wen-Wei; Shi, Bing-Jing; Yu, Han-Qing

2015-12-01

A novel energy-saving anaerobic hybrid membrane bioreactor (AnHMBR) with mesh filter, which takes advantage of anaerobic membrane bioreactor and fixed-bed biofilm reactor, is developed for low-strength 2-chlorophenol (2-CP)-contained wastewater treatment. In this system, the anaerobic membrane bioreactor is stuffed with granular activated carbon to construct an anaerobic hybrid fixed-bed biofilm membrane bioreactor. The effluent turbidity from the AnHMBR system was low during most of the operation period, and the chemical oxygen demand and 2-CP removal efficiencies averaged 82.3% and 92.6%, respectively. Furthermore, a low membrane fouling rate was achieved during the operation. During the AnHMBR operation, the only energy consumption was for feed pump. And a low energy demand of 0.0045-0.0063kWhm(-3) was estimated under the current operation conditions. All these results demonstrated that this novel AnHMBR is a sustainable technology for treating 2-CP-contained wastewater. Copyright © 2014 Elsevier Ltd. All rights reserved.

Extraction of lithium ion from alkaline aqueous media by a liquid surfactant membrane

International Nuclear Information System (INIS)

Kinugasa, Takumi; Ono, Yuri; Kawamura, Yuko; Watanabe, Kunio; Takeuchi, Hiroshi.

1995-01-01

Extraction of lithium ion from aqueous alkaline media by a liquid surfactant membrane was performed using a mixture of LIX54 and TOPO as the extractant. Stripping of lithium from the kerosene solution to the acid solution was suppressed with increasing content of polyamine (ECA) surfactant. The extraction rate of lithium by the liquid membrane could be interpreted taking account of an interfacial resistance due to ECA. It was confirmed that swelling of the (W/O) emulsion drops by water permeation through the liquid membrane is evaluated in terms of a change in osmotic pressure gradient between the external and internal aqueous phases during the lithium extraction. In the present operation, the extraction ratio of Li + from the external feed and the uptake into the internal phase reached as high as 95%. (author)

Addressing safety issues in a hybrid liquid metal reactor

International Nuclear Information System (INIS)

Garabedyan, D.; Ehvart, Eh.

1988-01-01

Hybrid design of a fast reactor with a liquid-metal coolant, combining the advantages of traditional loop (prevailing in the USA) and integral (prevailing in Europe) arrangements is described. Just as a loop reactor the hybrid one has separate arrangement of the core and the equipment of the primary circuit heat exchange. At the same time similar to the reactor with integral arrangement, the option considered has no complex pipeline system. This reduces sharply the possibility of sodium leakages which cause fires and personnel irradiation

Ionic Liquid-Nanoparticle Hybrid Electrolytes and their Application in Secondary Lithium-Metal Batteries

KAUST Repository

Lu, Yingying; Das, Shyamal K.; Moganty, Surya S.; Archer, Lynden A.

2012-01-01

Ionic liquid-tethered nanoparticle hybrid electrolytes comprised of silica nanoparticles densely grafted with imidazolium-based ionic liquid chains are shown to retard lithium dendrite growth in rechargeable batteries with metallic lithium anodes

Blanket of a hybrid thermonuclear reactor with liquid- metal cooling

International Nuclear Information System (INIS)

Terent'ev, I.K.; Fedorovich, E.P.; Paramonov, P.M.; Zhokhov, K.A.

1982-01-01

Blanket design of a hybrid thermopuclear reactor with a liquid metal coolant is described. To decrease MHD-resistance for uranium zone fuel elements a cylindrical shape is suggested and movement of liquid-metal coolant in fuel element packets is presumed to be in perpendicular to the magnetic field and fuel element axes direction. The first wall is cooled by water, blanket-by lithium-lead alloy

Cyclic Voltammetry of Highly Hydrophilic Ions at a Supported Liquid Membrane

Czech Academy of Sciences Publication Activity Database

Ulmeanu, S. M.; Jensen, H.; Samec, Zdeněk; Bouchard, G.; Carrupt, P. A.; Giraut, H. H.

2002-01-01

Roč. 530, 1/2 (2002), s. 10-15 ISSN 0022-0728 R&D Projects: GA AV ČR IAA4040902 Institutional research plan: CEZ:AV0Z4040901 Keywords : liquid-liquid interface * membrane * cyclic voltammetry Subject RIV: CG - Electrochemistry Impact factor: 2.027, year: 2002

Fundamental Study of Sorption of Pure Liquids and Liquid Mixtures into Polymeric Membrane

Czech Academy of Sciences Publication Activity Database

Randová, A.; Bartovská, L.; Friess, K.; Hovorka, Š.; Izák, Pavel

2014-01-01

Roč. 61, DEC 2014 (2014), s. 64-71 ISSN 0014-3057 R&D Projects: GA ČR(CZ) GAP106/12/0569 Institutional support: RVO:67985858 Keywords : organic liquids * gravimetric sorption * flat polymer membrane Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 3.005, year: 2014

Optical Biosensor with Multienzyme System Immobilized onto Hybrid Membrane for Pesticides Determination

Directory of Open Access Journals (Sweden)

Lyubov Yotova

2011-12-01

Full Text Available A construction of optical biosensor based on simultaneous immobilization of acetylcholinesterase and choline oxidase enzymes for the detection of pesticides residues is described. Different kinds of novel SiO2 hybrid membranes were synthesized to be suitable for optical biosensors using sol-gel techniques. The bioactive component of the sensor consists of a multi-enzyme system including acetylcholinesterase and choline oxidase covalently immobilized on new hybrid membranes. The sensor exhibited a linear response to acetylcholine in a concentration range of 2.5 - 30 mM. Inhibition plots obtained from testing carbamate (carbofuran pesticides exhibited concentration dependent behaviour and showed linear profiles in concentration ranges between 5x10-8 - 5x10-7 M for carbofuran. The factors affecting the constructed optical biosensors were investigated.

Polyethersulfone flat sheet and hollow fiber membranes from solutions in ionic liquids

KAUST Repository

Kim, Dooli; Vovusha, Hakkim; Schwingenschlö gl, Udo; Nunes, Suzana Pereira

2017-01-01

and mechanical strengths were evaluated. Membranes were applied to DNA separation. While membranes based on PES were successfully prepared, polysulfone (PSf) does not dissolve in the same ionic liquids. The discrepancy between PES and PSf could not be explained

Chemically Stable Covalent Organic Framework (COF)-Polybenzimidazole Hybrid Membranes: Enhanced Gas Separation through Pore Modulation.

Science.gov (United States)

Biswal, Bishnu P; Chaudhari, Harshal D; Banerjee, Rahul; Kharul, Ulhas K

2016-03-24

Highly flexible, TpPa-1@PBI-BuI and TpBD@PBI-BuI hybrid membranes based on chemically stable covalent organic frameworks (COFs) could be obtained with the polymer. The loading obtained was substantially higher (50 %) than generally observed with MOFs. These hybrid membranes show an exciting enhancement in permeability (about sevenfold) with appreciable separation factors for CO2/N2 and CO2/CH4. Further, we found that with COF pore modulation, the gas permeability can be systematically enhanced. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

High ionic liquid content polymeric gel membranes: Preparation and performance

Czech Academy of Sciences Publication Activity Database

Jansen, J. C.; Friess, K.; Clarizia, G.; Schauer, Jan; Izák, Pavel

2011-01-01

Roč. 44, č. 1 (2011), s. 39-45 ISSN 0024-9297 R&D Projects: GA ČR GA203/08/0465; GA ČR GAP106/10/1194 Institutional research plan: CEZ:AV0Z40500505; CEZ:AV0Z40720504 Keywords : ionic liquid membrane * gas separation membrane * 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide Subject RIV: CD - Macromolecular Chemistry Impact factor: 5.167, year: 2011

On the enhancement of pervaporation properties of plasma-deposited hybrid silica membranes

Energy Technology Data Exchange (ETDEWEB)

Ngamou, P.H.T.; Creatore, M. [Department of Applied Physics, Eindhoven University of Technology, 5600 MB Eindhoven (Netherlands); Overbeek, J.P.; Kreiter, R.; Van Veen, H.M.; Vente, J.F. [ECN, Energy research Centre of the Netherlands, Petten (Netherlands); Cuperus, P.F. [SolSep BV, Apeldoorn (Netherlands)

2013-06-24

The separation performance of a polymeric-supported hybrid silica membrane in the dehydration process of a butanol-water mixture at 95C has been enhanced by applying a bias to the substrate during the plasma deposition.

Transport of uranium by supported liquid membrane containing bis(2-ethylhexyl) hydrogenphosphate and 1-octanol

International Nuclear Information System (INIS)

Akiba, Kenichi; Kanno, Takuji; Takahashi, Toshihiko.

1984-01-01

Carrier-mediated transport of uranium(VI) has been studied by means of liquid membranes impregnated in a microporous polymer. Liquid membranes containing bis(2-ethylhexyl) hydrogenphosphate (DEHPA) alone yielded inadequate stripping of uranium. The addition of 1-octanol to DEHPA solutions resulted in a decrease in extractability, and made it possible to control the distribution ratio of uranium. Uranium in the feed solution was sufficiently transported across the liquid membrane containing this DEHPA-1-octanol mixture into the product solution. The apparent rate constant (ksub(obs)) of transport increased slightly with an increase in carrier concentrations. Variations in acid concentrations of the feed solution (pH 2.5--3.2) and the product solution (0.1--1.0 M H 2 SO 4 ) had little effect on the transport rate. A large excess of uranium, more than the carrier content in the liquid membrane, was finally concentrated in the stripping acid. (author)

Hybrid membrane-microfluidic components using a novel ceramic MEMS technology

Science.gov (United States)

Lutz, Brent J.; Polyakov, Oleg; Rinaldo, Chris

2012-03-01

A novel hybrid nano/microfabrication technology has been employed to produce unique MEMS and microfluidic components that integrate nanoporous membranes. The components are made by micromachining a self-organized nanostructured ceramic material that is biocompatible and amenable to surface chemistry modification. Microfluidic structures, such as channels and wells, can be made with a precision of membranes can be integrated into the bottom of these structures, featuring a wide range of possible thicknesses, from 100 micron to membranes may be non-porous or porous (with controllable pore sizes from 200 nm to technology is highly scaleable, and thus can yield low-cost, reliable, disposable microcomponents and devices. Specific applications that can benefit from this technology includes cell culturing and assays, imaging by cryo-electron tomography, environmental sample processing, as well as many others.

Transport of phosphoric acid through supported liquid membrane

International Nuclear Information System (INIS)

Zayzafoon, G.; Yassine, T.; Baidoun, R.

2003-01-01

The transport of phosphhoric acid through liquid membranes of amylalkohol, 1-octanol and 2-octanol was studied. It was found that phosphoric acid is transfered from feed side to strip side and the transport increased with the concentration of phosphoric acid up to 5M. The permeability in each membrane was determined for 5M phosphoic acid. It was found that the permeability values are 1.45 x 10 1 0 m 2 s 1 for amylakohol and ∼ 1x10 1 0 m 2 s 1 for each of 1-octanol and 2-octanol

Membrane technologies for liquid radioactive waste treatment

International Nuclear Information System (INIS)

Chmielewski, A.G.; Harasimowicz, M.; Zakrzewska-Trznadel, G.

1998-01-01

At Institute of Nuclear Chemistry and Technology (INCT) the membrane method for purification of radioactive wastes applied such processes as ultrafiltration (UF), 'seeded' ultrafiltration and reverse osmosis (RO) was developed. On the basis of the results obtained in laboratory experiments the pilot plant for radioactive effluents treatment was built. The plant was composed of UF unit (AMICON H 26P30 capillary module) and two RO units (NITTO NTR 739 HF S-4 spiral wound LPRO modules). The capacity of the pilot plant was up to 200 L/h and the specific activity of wastes purified in the system - below 10 4 Bq/L. Decontamination factor for entire system is higher than 5 x10 3 . Another possibility for radioactive wastes treatment is membrane distillation (MD), non-isothermal process employing hydrophobic polymer membrane, which is developed at INCT now. Preliminary tests with liquid radwaste were carried out on laboratory unit with permeation test-cell holding flat sheet membrane. As a hydrophobic barrier membranes made of two polymers were used: polytetrafluoroethylene (PTFE) and polypropylene (PP). The process was arranged in direct contact membrane distillation configuration. The permeate condensed directly in the cold stream (distilled water) and retentate was enriched in radionuclides. The further experiments carried out with capillary module BFMF 06-30-33 (Euro-Sep Ltd.) with polypropylene capillaries, diameter 0.33 mm and cut off 0.6 μm proved previous results. A pilot plant employing GORE-TEX membrane distillation was constructed. The plant can clean the low-level radioactive wastes from nuclear centre, at a throughput about 0.05 m 3 /h

Novel Water Treatment Processes Based on Hybrid Membrane-Ozonation Systems: A Novel Ceramic Membrane Contactor for Bubbleless Ozonation of Emerging Micropollutants

Directory of Open Access Journals (Sweden)

Stylianos K. Stylianou

2015-01-01

Full Text Available The aim of this study is the presentation of novel water treatment systems based on ozonation combined with ceramic membranes for the treatment of refractory organic compounds found in natural water sources such as groundwater. This includes, firstly, a short review of possible membrane based hybrid processes for water treatment from various sources. Several practical and theoretical aspects for the application of hybrid membrane-ozonation systems are discussed, along with theoretical background regarding the transformation of target organic pollutants by ozone. Next, a novel ceramic membrane contactor, bringing into contact the gas phase (ozone and water phase without the creation of bubbles (bubbleless ozonation, is presented. Experimental data showing the membrane contactor efficiency for oxidation of atrazine, endosulfan, and methyl tert-butyl ether (MTBE are shown and discussed. Almost complete endosulfan degradation was achieved with the use of the ceramic contactor, whereas atrazine degradation higher than 50% could not be achieved even after 60 min of reaction time. Single ozonation of water containing MTBE could not result in a significant MTBE degradation. MTBE mineralization by O3/H2O2 combination increased at higher pH values and O3/H2O2 molar ratio of 0.2 reaching a maximum of around 65%.

Changes in the Fatty Acid Profile and Phospholipid Molecular Species Composition of Human Erythrocyte Membranes after Hybrid Palm and Extra Virgin Olive Oil Supplementation.

Science.gov (United States)

Pacetti, D; Gagliardi, R; Balzano, M; Frega, N G; Ojeda, M L; Borrero, M; Ruiz, A; Lucci, P

2016-07-13

This work aims to evaluate and compare, for the first time, the effects of extra virgin olive oil (EVOO) and hybrid palm oil (HPO) supplementation on the fatty acid profile and phospholipid (PL) molecular species composition of human erythrocyte membranes. Results supported the effectiveness of both HPO and EVOO supplementation (3 months, 25 mL/day) in decreasing the lipophilic index of erythrocytes with no significant differences between HPO and EVOO groups at month 3. On the other hand, the novel and rapid ultraperformance liquid chromatography-tandem mass spectrometry method used for PL analysis reveals an increase in the levels of phosphatidylcholine and phosphatidylethanolamine species esterified with polyunsaturated fatty acids. This work demonstrates the ability of both EVOO and HPO to increase the degree of unsaturation of erythrocyte membrane lipids with an improvement in membrane fluidity that could be associated with a lower risk of developing cardiovascular diseases.

Geometric methods in the elastic theory of membranes in liquid crystal phases

CERN Document Server

Ji Xing Liu; Yu Zhang Xie

1999-01-01

This book contains a comprehensive description of the mechanical equilibrium and deformation of membranes as a surface problem in differential geometry. Following the pioneering work by W Helfrich, the fluid membrane is seen as a nematic or smectic - A liquid crystal film and its elastic energy form is deduced exactly from the curvature elastic theory of the liquid crystals. With surface variation the minimization of the energy at fixed osmotical pressure and surface tension gives a completely new surface equation in geometry that involves potential interest in mathematics. The investigations

Fabrication of Well-Ordered, Anodic Aluminum Oxide Membrane Using Hybrid Anodization.

Science.gov (United States)

Kim, Jungyoon; Ganorkar, Shraddha; Choi, Jinnil; Kim, Young-Hwan; Kim, Seong-II

2017-01-01

Anodic Aluminum Oxide (AAO) is one of the most favorable candidates for fabrication of nano-meshed membrane for various applications due to its controllable pore size and self-ordered structure. The mechanism of AAO membrane is a simple and has been studied by many research groups, however the actual fabrication of membrane has several difficulties owing to its sensitivity of ordering, long anodizing time and unclearness of the pore. In this work, we have demonstrated enhanced process of fabrication symmetric AAO membrane by using “hybrid anodizing” (Hyb-A) method which include mild anodization (MA) followed by hard anodization (HA). This Hyb-A process can give highly ordered membrane with more vivid pore than two-step anodizing process. HA was implemented on the Al plate which has been already textured by MA for more ordered structure and HA plays a key role for formation of more obvious pore in Hyb-A. Our experimental results indicate that Hyb-A with proper process sequence would be one of the fast and useful fabrication methods for the AAO membrane.

Covalent Crosslinking of Porous Poly(Ionic Liquid) Membrane via a Triazine Network

OpenAIRE

Täuber, Karoline; Dani, Alessandro; Yuan, Jiayin

2017-01-01

Porous poly(ionic liquid) membranes that were prepared via electrostatic cross-linking were subsequently covalently cross-linked via formation of a 1,3,5-triazine network. The additional covalent cross-links do not affect the pore size and pore size distribution of the membranes and stabilize them towards salt solutions of high ionic strength, enabling the membranes to work in a broader environmental window.

Parallel artificial liquid membrane extraction of new psychoactive substances in plasma and whole blood

DEFF Research Database (Denmark)

Vårdal, Linda; Askildsen, Hilde-Merete; Gjelstad, Astrid

2017-01-01

Parallel artificial liquid membrane extraction (PALME) was combined with ultra-high performance liquid chromatography-mass spectrometry (UHPLC–MS) and the potential for screening of new psychoactive substances (NPS) was investigated for the first time. PALME was performed in 96-well format...... comprising a donor plate, a supported liquid membrane (SLM), and an acceptor plate. Uncharged NPS were extracted from plasma or whole blood, across an organic SLM, and into an aqueous acceptor solution, facilitated by a pH gradient. MDAI (5,6-methylenedioxy-2-aminoindane), methylone, PFA (para...

Two orders of magnitude reduction in silicon membrane thermal conductivity by resonance hybridizations

Science.gov (United States)

Honarvar, Hossein; Hussein, Mahmoud I.

2018-05-01

The thermal conductivity of a freestanding single-crystal silicon membrane may be reduced significantly by attaching nanoscale pillars on one or both surfaces. Atomic resonances of the nanopillars form vibrons that intrinsically couple with the base membrane phonons causing mode hybridization and flattening at each coupling location in the phonon band structure. This in turn causes group velocity reductions of existing phonons, in addition to introducing new modes that get excited but are localized and do not transport energy. The nanopillars also reduce the phonon lifetimes at and around the hybridization zones. These three effects, which in principle may be tuned to take place across silicon's full spectrum, lead to a lowering of the in-plane thermal conductivity in the base membrane. Using equilibrium molecular dynamics simulations, and utilizing the concept of vibrons compensation, we report a staggering two orders of magnitude reduction in the thermal conductivity at room temperature by this mechanism. Specifically, a reduction of a factor of 130 is demonstrated for a roughly 10-nm-thick pillared membrane compared to a corresponding unpillared membrane. This amounts to a record reduction of a factor of 481 compared to bulk crystalline silicon and nearly a factor of 2 compared to bulk amorphous silicon. These results are obtained while providing a path for preserving performance with upscaling.

Boron removal in radioactive liquid waste by forward osmosis membrane

Energy Technology Data Exchange (ETDEWEB)

Doo Seong Hwang; Hei Min Choi; Kune Woo Lee; Jei Kwon Moon [KAERI, Daejeon (Korea, Republic of)

2013-07-01

This study investigated the treatment of boric acid contained in liquid radioactive waste using a forward osmosis membrane. The boron permeation through the membrane depends on the type of membrane, membrane orientation, pH of the feed solution, salt and boron concentration in the feed solution, and osmotic pressure of the draw solution. The boron flux begins to decline from pH 7 and increases with an increase of the osmotic driving force. The boron flux decreases slightly with the salt concentration, but is not heavily influenced by a low salt concentration. The boron flux increases linearly with the concentration of boron. No element except for boron was permeated through the FO membrane in the multi-component system. The maximum boron flux is obtained in an active layer facing a draw solution orientation of the CTA-ES membrane under conditions of less than pH 7 and high osmotic pressure. (authors)

Co3O4 nanoneedle@electroactive nickel boride membrane core/shell arrays: A novel hybrid for enhanced capacity

International Nuclear Information System (INIS)

Li, Tingting; Zhu, Congxu; Yang, Xiaogang; Gao, Yuanhao; He, Weiwei; Yue, Hongwei; Zhao, Hongxiao

2017-01-01

Graphical abstract: Active nickel boride membrane anchored Co 3 O 4 nanoneedle arrays hybrid is synthesized via rapid interface reaction. The optimized core/shell nanostructure demonstrates greatly enhanced electrochemical properties. Display Omitted -- Highlights: •Active nickel boride membrane anchored Co 3 O 4 nanoneedle arrays core-shell hybrid architectures was fabricated via rapid interface reaction. •Specific capacity was improved by synergy between highly active components and optimized electron transfer microstructure. •The assembled asymmetric supercapacitor device exhibited excellent electrochemical performance. -- Abstract: Exploring novel hybrid materials with efficient microstructure using facile approaches is highly urgent in designing supercapacitor electrodes. Here, the Ni-B membrane was used for coating the porous Co 3 O 4 nanoneedle arrays which supported on the nickel foam (NF) frameworks through a rapid chemical reduction process (denoted as NF/Co 3 O 4 @NiB). The Ni-B membrane both provided sufficient active sites for redox reactions and inhibited the aggregation of formed hybrid architectures. Benefiting from the unique structural design and strongly coupled effects between porous Co 3 O 4 arrays and Ni-B membrane, the resulted NF/Co 3 O 4 @NiB electrode exhibited high areal capacitance of 3.47 F cm −2 (0.48 mAh cm −2 ) at a current density of 2.5 mA cm −2 , an excellent rate capability while maintaining 95.5% capacity retention after 2000 cycles. The asymmetric supercapacitor constructed with the NF/Co 3 O 4 @NiB as positive electrode and hierarchical porous carbon (HPC) as negative electrode also showed ideal capacitive behavior, and simultaneously delivered high energy and power densities. The easily decoration of Ni-B membrane on various active nanoarrays may arouse more novel design about hybrid architectures for large-scale applications.

Nature-inspired multifunctional membrane fabricated by adaptive hybridization of PNIPAm and PPy

Science.gov (United States)

Kim, Hyejeong; Kim, Kiwoong; Lee, Sang Joon

2017-11-01

Specialized plant organs, such as guard cells of stomata, consist of soft materials with deformability and electrochemical properties in response to various environmental stimuli. Stimulus-responsive hydrogels with electrochemical properties are good candidates for imitating such functionalities having great potential in a wide range of applications. However, conductive hydrogels are usually mechanically rigid and the fabrication technology of structured hydrogels has low reproducibility. Here, inspired by stimulus-responsive functionalities of plants, a thermo-responsive multifunctional hybrid membrane (HM) is synthesized through the in situ hybridization of conductive poly(pyrrole)(PPy) on a photopolymerized poly(N-isopropylacrylamide)(PNIPAm) membrane. The various properties of the HM are investigated to characterize its multiple functions. In terms of morphology, the HM can be easily fabricated into various structures, and exhibits thermo-responsive deformability. In terms of functionality, it exhibits various electrical and charge responses to thermal stimuli. This simple and efficient fabrication method can be used as a promising platform for fabricating a variety of functional devices, such as actuators, biosensors, and filtration membranes. This work was supported by the National Research Foundation of Korea (NRF) Grant funded by the Korean government (MSIP) (No. 2017R1A2B3005415).

Extraction separation of toluene/cyclohexane with hollow fiber supported ionic liquid membrane

Energy Technology Data Exchange (ETDEWEB)

Zhang, Fan; Sun, Wei; Liu, Junteng; Zhang, Weidong; Ren, Zhongqi [Beijing University of Chemical Technology, Beijing (China)

2014-06-15

A supported liquid membrane with ionic liquid was used for the separation of toluene/cyclohexane. The interactions of ionic liquid with toluene and cyclohexane were calculated and experimentally studied by quantum chemical calculation and liquid-liquid extraction process. The results showed [BPy][BF{sub 4}] have stronger interaction with toluene than that with cyclohexane. The selectivity of SILM processes was larger than 10 at the temperature of 323 K and the flow rate of 13.5 mL·min{sup -1} on both shell side and lumen side. Due to the higher viscosity of IL, SILM process had good long-term stability. As the effects of mass transfer driving force of SILM process, the flux and removal efficiency increased with increase of initial toluene concentration, while the selectivity decreased because of the competitive transport. Base on the resistance in-series model and experimental results, the mass transfer resistance was mainly lay liquid membrane phase. The influence of flow rates on both sides was slight. The higher temperature could enhance the mass transfer performance significantly. The removal efficiency increased from 28.2% to 45.1% with the increasing of operation temperature from 298 K to 323 K.

An investigation of desalination by nanofiltration, reverse osmosis and integrated (hybrid NF/RO) membranes employed in brackish water treatment.

Science.gov (United States)

Talaeipour, M; Nouri, J; Hassani, A H; Mahvi, A H

2017-01-01

As an appropriate tool, membrane process is used for desalination of brackish water, in the production of drinking water. The present study aims to investigate desalination processes of brackish water of Qom Province in Iran. This study was carried out at the central laboratory of Water and Wastewater Company of the studied area. To this aim, membrane processes, including nanofiltration (NF) and reverse osmosis (RO), separately and also their hybrid process were applied. Moreover, water physical and chemical parameters, including salinity, total dissolved solids (TDS), electric conductivity (EC), Na +1 and Cl -1 were also measured. Afterward, the rejection percent of each parameter was investigated and compared using nanofiltration and reverse osmosis separately and also by their hybrid process. The treatment process was performed by Luna domestic desalination device, which its membrane was replaced by two NF90 and TW30 membranes for nanofiltration and reverse osmosis processes, respectively. All collected brackish water samples were fed through membranes NF90-2540, TW30-1821-100(RO) and Hybrid (NF/RO) which were installed on desalination household scale pilot (Luna water 100GPD). Then, to study the effects of pressure on permeable quality of membranes, the simulation software model ROSA was applied. Results showed that percent of the salinity rejection was recorded as 50.21%; 72.82 and 78.56% in NF, RO and hybrid processes, respectively. During the study, in order to simulate the performance of nanofiltartion, reverse osmosis and hybrid by pressure drive, reverse osmosis system analysis (ROSA) model was applied. The experiments were conducted at performance three methods of desalination to remove physic-chemical parameters as percentage of rejections in the pilot plant are: in the NF system the salinity 50.21, TDS 43.41, EC 43.62, Cl 21.1, Na 36.15, and in the RO membrane the salinity 72.02, TDS 60.26, EC 60.33, Cl 43.08, Na 54.41. Also in case of the rejection in

Mercury Concentration Reduction In Waste Water By Using Liquid Surfactant Membrane Technique

International Nuclear Information System (INIS)

Prayitno; Sardjono, Joko

2000-01-01

The objective of this research is ti know effectiveness of liquid surfactant membrane in diminishing mercury found in waste water. This process can be regarded as transferring process of solved mercury from the external phase functioning as a moving phase to continue to the membrane internal one. The existence of the convection rotation results in the change of the surface pressure on the whole interface parts, so the solved mercury disperses on every interface part. Because of this rotation, the solved mercury will fulfil every space with particles from dispersion phase in accordance with its volume. Therefore, the change of the surface pressure on the whole interface parts can be kept stable to adsorb mercury. The mercury adsorbed in the internal phase moves to dispersed particles through molecule diffusion process. The liquid surfactant membrane technique in which the membrane phase is realized into emulsion contains os kerosene as solvent, sorbitan monoleat (span-80) 5 % (v/v) as surfactant, threbuthyl phosphate (TBP) 10 % (v/v) as extractant, and solved mercury as the internal phase. All of those things are mixed and stirred with 8000 rpm speed for 20 minutes. After the stability of emulsion is formed, the solved mercury is extracted by applying extraction process. The effective condition required to achieve mercury ion recovery utilizing this technique is obtained through extraction and re-extraction process. This process was conducted in 30 minutes with membrane and mercury in scale 1 : 1 on 100 ppm concentration. The results of the processes was 99,6 % efficiency. This high efficiency shows that the liquid surfactant membrane technique is very effective to reduce waste water contamined by mercury

chemical studies on the extraction of certain metal ions from aqueous solution by liquid emulsion membrane

International Nuclear Information System (INIS)

Kassem, A.T.

2011-01-01

In this thesis four systems are addressed related to the use of liquid emulsion membranes (ELM) based on Co(III)dicarbiolide and. The system was dedicated for permeation of cadmium , cobalt Nickel and lead for use of this system for preconcentration and separation of cadmium, cobalt, nickel and lead. The work carried out in this thesis is presented in three parts, namely; introduction, experimental and results and discussion.The first chapter is the introduction which includes aim of work, basic concepts of liquid membranes; liquid emulsion membranes; different models of emulsion permeation, literature survey of extraction chemistry of cadmium, cobalt, nickel and lead. Chapter two includes the experimental part. In this part detailed outlines on the chemicals and different elements used were given. Different instruments as well as analytical techniques were outlines. The preparation of liquid emulsion membrane and the permeation techniques were presented in details. The third chapter deals with the results and discussion. This chapter is divided into four main parts, the four parts is concerned with cadmium/Co(III) dicarbolide/NTA, EDTA, DPTA and DCTA systems. In this part the permeation of Cd(II) aqueous solution by the membrane used was experimented based on liquid-liquid extraction studies of cadmium from different sodium chloride molarities (from 0.01 to 0.1 M) by 0.01 M Cobalt(III) dicarbolides. It was found that the extraction of with cadmium is higher following in the first system, the permeation of the toxic elements, Cd(II) from HCl/sodium chloride medium was carried out using liquid emulsion membrane containing Co(III)dicarbiolide in xylene as carrier, Spain 80/ Spain 85(1:3) as surfactant and NTA, EDTA, DPTA and DCTA as a stripping solutions.

Cleaning of liquid LLW from decontamination processes using semipermeable membranes

International Nuclear Information System (INIS)

Dulama, M.; Deneanu, N.; Pavelescu, M.

2003-01-01

Of the three processes, which have been used extensively for liquid radioactive waste purification, evaporation and ion exchange are costly and flocculation gives a low degree of purification. By comparison to that, reverse osmosis offers intermediate purification at reasonable cost. Present research is examining the potential of using a membrane filtration system for the removal of dissolved radionuclides, but chemical treatment showed as necessary to convert soluble radionuclides, organic traces and metals to insoluble, filterable species. Liquid wastes within a CANDU station are segregated into normal and low-activity waste streams. The normal-activity waste includes wastes from the laboratories, laundries, some service-building drains, upgrade drains, and decontamination center. The drains from the reactor building, the heavy-water area, the spent-fuel pool, and the resin storage area are also directed to this normal activity wastes from showers and building drains in areas of the service building that would not normally be contaminated. The aqueous liquid wastes from the decontamination center and the other collected wastes from the chemical drain system are currently treated by the membrane plant. Generally, the liquid waste streams are effectively volume-reduced by a combination of continuous crossflow microfiltration (MF), spiral wound reverse osmosis (SWRO) and tubular reverse osmosis membrane technologies. Backwash chemical cleaning wastes from the membrane plant are further volume-reduced by evaporation. The concentrate from the membrane plant is ultimately immobilized with bitumen. The ability of the MF/SWRO technology to remove impurities non-selectively makes it suitable for the treatment of radioactive effluents from operating nuclear plants, with proper membrane selection, feed characterization, system configuration and system chemistry control. The choice of polysulfonate material for membrane was based on the high flow rates achievable with this

Effect of ozone on the performance of a hybrid ceramic membrane-biological activated carbon process.

Science.gov (United States)

Guo, Jianning; Hu, Jiangyong; Tao, Yi; Zhu, Jia; Zhang, Xihui

2014-04-01

Two hybrid processes including ozonation-ceramic membrane-biological activated carbon (BAC) (Process A) and ceramic membrane-BAC (Process B) were compared to treat polluted raw water. The performance of hybrid processes was evaluated with the removal efficiencies of turbidity, ammonia and organic matter. The results indicated that more than 99% of particle count was removed by both hybrid processes and ozonation had no significant effect on its removal. BAC filtration greatly improved the removal of ammonia. Increasing the dissolved oxygen to 30.0 mg/L could lead to a removal of ammonia with concentrations as high as 7.80 mg/L and 8.69 mg/L for Processes A and B, respectively. The average removal efficiencies of total organic carbon and ultraviolet absorbance at 254 nm (UV254, a parameter indicating organic matter with aromatic structure) were 49% and 52% for Process A, 51% and 48% for Process B, respectively. Some organic matter was oxidized by ozone and this resulted in reduced membrane fouling and increased membrane flux by 25%-30%. However, pre-ozonation altered the components of the raw water and affected the microorganisms in the BAC, which may impact the removals of organic matter and nitrite negatively. Copyright © 2014 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

Non-porous membrane-assisted liquid-liquid extraction of UV filter compounds from water samples.

Science.gov (United States)

Rodil, Rosario; Schrader, Steffi; Moeder, Monika

2009-06-12

A method for the determination of nine UV filter compounds [benzophenone-3 (BP-3), isoamyl methoxycinnamate, 4-methylbenzylidene camphor, octocrylene (OC), butyl methoxydibenzoylmethane, ethylhexyl dimethyl p-aminobenzoate (OD-PABA), ethylhexyl methoxycinnamate (EHMC), ethylhexyl salicylate and homosalate] in water samples was developed and evaluated. The procedure includes non-porous membrane-assisted liquid-liquid extraction (MALLE) and LC-atmospheric pressure photoionization (APPI)-MS/MS. Membrane bags made of different polymeric materials were examined to enable a fast and simple extraction of the target analytes. Among the polymeric materials tested, low- and high-density polyethylene membranes proved to be well suited to adsorb the analytes from water samples. Finally, 2 cm length tailor-made membrane bags were prepared from low-density polyethylene in order to accommodate 100 microL of propanol. The fully optimised protocol provides recoveries from 76% to 101% and limits of detection (LOD) between 0.4 ng L(-1) (OD-PABA) and 16 ng L(-1) (EHMC). The interday repeatability of the whole protocol was below 18%. The effective separation of matrix molecules was proved by only marginal matrix influence during the APPI-MS analysis since no ion suppression effects were observed. During the extraction step, the influence of the matrix was only significant when non-treated wastewater was analysed. The analysis of lake water indicated the presence of seven UV filter compounds included in this study at concentrations between 40 ng L(-1) (BP-3) and 4381 ng L(-1) (OC). In non-treated wastewater several UV filters were also detected at concentration levels as high as 5322 ng L(-1) (OC).

Characterization of a supported ionic liquid membrane used for the removal of cyanide from wastewater.

Science.gov (United States)

Xue, Juan Qin; Liu, Ni Na; Li, Guo Ping; Dang, Long Tao

2017-12-01

This work evaluated the performance of ionic liquids (ILs) in supported liquid membranes in the removal of total cyanide from wastewater. Membranes were characterized by scanning electron microscopy and contact angle measurements to study the membrane morphology and wetting ability. In particular, the effects of operational parameters such as membrane immersion time, feed-phase concentration, and pH on cyanide removal were investigated. ILs are organic salts that are entirely composed of organic cations and either organic or inorganic anions. Since their vapor pressure is negligible, they can be handled easily; this characteristic gives rise to their 'green' nature. In this study, a hydrophobic IL, 1-butyl-3-methylimidazolium hexafluorophosphate ([Bmim]PF 6 ), was immobilized in the pores of a solid polymeric support made of polyvinylidene fluoride. The optimal conditions were as follows: 1 hour membrane immersion time, 312.24 mg/L feed-phase concentration, a feed-phase pH of 4, 3% NaOH solution, and 1 hour stirring time. The cyanide removal was 95.31%. The treatment of cyanide using supported ionic liquid membrane (SILM) technology is a method with potential applications in industry.

Numerical evaluation of various gas and coolant channel designs for high performance liquid-cooled proton exchange membrane fuel cell stacks

International Nuclear Information System (INIS)

Sasmito, Agus P.; Kurnia, Jundika C.; Mujumdar, Arun S.

2012-01-01

A careful design of gas and coolant channel is essential to ensure high performance and durability of proton exchange membrane (PEM) fuel cell stack. The channel design should allow for good thermal, water and gas management whilst keeping low pressure drop. This study evaluates numerically the performance of various gas and coolant channel designs simultaneously, e.g. parallel, serpentine, oblique-fins, coiled, parallel-serpentine and a novel hybrid parallel-serpentine-oblique-fins designs. The stack performance and local distributions of key parameters are investigated with regards to the thermal, water and gas management. The results indicate that the novel hybrid channel design yields the best performance as it constitutes to a lower pumping power and good thermal, water and gas management as compared to conventional channels. Advantages and limitation of the designs are discussed in the light of present numerical results. Finally, potential application and further improvement of the design are highlighted. -- Highlights: ► We evaluate various gas and coolant channel designs in liquid-cooled PEM fuel cell stack. ► The model considers coupled electrochemistry, channel design and cooling effect simultaneously. ► We propose a novel hybrid channel design. ► The novel hybrid channel design yields the best thermal, water and gas management which is beneficial for long term durability. ► The novel hybrid channel design exhibits the best performance.

Uranyl ion transport across tri-n-butyl phosphate/n-dodecane liquid membranes

International Nuclear Information System (INIS)

Shukla, J.P.; Misra, S.K.

1991-01-01

Carrier-facilitated transport of uranium (VI) against its concentration gradient from aqueous nitrate acidic solutions across organic bulk liquid membranes (BLM) and supported liquid membranes (SLM) containing TBP as the mobile carrier and n-dodecane as the membrane solvent was investigated. Extremely dilute uranyl nitrate solutions in about 2.5 M nitric acid generally constituted as the source phase. Uranyl transport appreciably increased with both stirring of the receiving phase and the carrier concentration in the organic membrane, while enhanced acidity of the strip side adversely affected the partioning of the cation into this phase. Among the several reagents tested, diluted ammonium carbonate (∼1M) solutions served efficiently as the stripant. Besides Accurel polypropylene (PP) film as the solid support for SLM, some silicon flat-sheet membranes with different inorganic fillers like silica, calcium silicate, calcium carbonate, chromium oxide, zinc oxide etc. and teflon membranes transported about 70% of uranium in nearly 7-8 hr employing 1 M ammonium carbonate as the strippant. Specifically, 30% TBP supported on Accurel flat-sheet supports transfered better than 70% of uranium from moderate acid feeds (2.5M) under similar conditions. Membranes supporting Aliquat-336, TLA, TOPO etc. yielded somewhat poor uranium recoveries. The feed : strip volume ratio showed an inverse relationship to the fraction of cation transported. (author). 9 refs., 2 tab s

Selective enantioseparation of levocetirizine via a hollow fiber supported liquid membrane and mass transfer prediction

International Nuclear Information System (INIS)

Sunsandee, Niti; Leepipatpiboon, Natchanun; Ramakul, Prakorn

2013-01-01

The enantioselective separation of levocetirizine via a hollow fiber supported liquid membrane was examined. O,O'-dibenzoyl-(2R,3R)-tartaric acid ((-)-DBTA) diluted in 1-decanol was used as a chiral selector extractant. The influence of concentrations of feed and stripping phases, and extractant concentration in the membrane phase, was also investigated. A mathematical model focusing on the extraction side of the liquid membrane system was presented to predict the concentration of levocetirizine at different times. The extraction and recovery of levocetirizine from feed phase were 75.00% and 72.00%, respectively. The mass transfer coefficients at aqueous feed boundary layer (k_f) and the organic liquid membrane phase (k_m) were calculated as 2.41x10"2 and 1.89x10"2 cm/s, respectively. The validity of the developed model was evaluated through a comparison with experimental data, and good agreement was obtained

Analysis of hybrid membrane and chemical absorption systems for CO2 capture

International Nuclear Information System (INIS)

Binns, Michael; Oh, Se-Young; Kwak, Dong-Hun; Kim, Jin-Kuk

2015-01-01

Amine-based absorption of CO 2 is currently the industry standard technology for capturing CO 2 emitted from power plants, refineries and other large chemical plants. However, more recently there have been a number of competing technologies under consideration, including the use of membranes for CO 2 separation and purification. We constructed and analyzed two different hybrid configurations combining and connecting chemical absorption with membrane separation. For a particular flue gas which is currently treated with amine-based chemical absorption at a pilot plant we considered and tested how membranes could be integrated to improve the performance of the CO 2 capture. In particular we looked at the CO 2 removal efficiency and the energy requirements. Sensitivity analysis was performed varying the size of the membranes and the solvent flow rate

Hybrid flotation--membrane filtration process for the removal of heavy metal ions from wastewater.

Science.gov (United States)

Blöcher, C; Dorda, J; Mavrov, V; Chmiel, H; Lazaridis, N K; Matis, K A

2003-09-01

A promising process for the removal of heavy metal ions from aqueous solutions involves bonding the metals firstly to a special bonding agent and then separating the loaded bonding agents from the wastewater stream by separation processes. For the separation stage, a new hybrid process of flotation and membrane separation has been developed in this work by integrating specially designed submerged microfiltration modules directly into a flotation reactor. This made it possible to combine the advantages of both flotation and membrane separation while overcoming the limitations. The feasibility of this hybrid process was proven using powdered synthetic zeolites as bonding agents. Stable fluxes of up to 80l m(-2)h(-1) were achieved with the ceramic flat-sheet multi-channel membranes applied at low transmembrane pressure (copper, nickel and zinc, were reduced from initial concentrations of 474, 3.3 and 167mg x l(-1), respectively, to below 0.05 mg x l(-1), consistently meeting the discharge limits.

Increasing the operation temperature of polymer electrolyte membranes for fuel cells: From nanocomposites to hybrids

Science.gov (United States)

Licoccia, Silvia; Traversa, Enrico

Among the possible systems investigated for energy production with low environmental impact, polymeric electrolyte membrane fuel cells (PEMFCs) are very promising as electrochemical power sources for application in portable technology and electric vehicles. For practical applications, operating FCs at temperatures above 100 °C is desired, both for hydrogen and methanol fuelled cells. When hydrogen is used as fuel, an increase of the cell temperature produces enhanced CO tolerance, faster reaction kinetics, easier water management and reduced heat exchanger requirement. The use of methanol instead of hydrogen as a fuel for vehicles has several practical benefits such as easy transport and storage, but the slow oxidation kinetics of methanol needs operating direct methanol fuel cells (DMFCs) at intermediate temperatures. For this reason, new membranes are required. Our strategy to achieve the goal of operating at temperatures above 120 °C is to develop organic/inorganic hybrid membranes. The first approach was the use of nanocomposite class I hybrids where nanocrystalline ceramic oxides were added to Nafion. Nanocomposite membranes showed enhanced characteristics, hence allowing their operation up to 130 °C when the cell was fuelled with hydrogen and up to 145 °C in DMFCs, reaching power densities of 350 mW cm -2. The second approach was to prepare Class II hybrids via the formation of covalent bonds between totally aromatic polymers and inorganic clusters. The properties of such covalent hybrids can be modulated by modifying the ratio between organic and inorganic groups and the nature of the chemical components allowing to reach high and stable conductivity values up to 6.4 × 10 -2 S cm -1 at 120 °C.

Rapid One-Pot Microwave Synthesis of Mixed-Linker Hybrid Zeolitic-Imidazolate Framework Membranes for Tunable Gas Separations.

Science.gov (United States)

Hillman, Febrian; Brito, Jordan; Jeong, Hae-Kwon

2018-02-14

The relatively slow and complex fabrication processes of polycrystalline metal-organic framework (MOF) membranes often times restrict their way to commercialization, despite their potential for molecular separation applications. Herein, we report a rapid one-pot microwave synthesis of mixed-linker hybrid zeolitic-imidazolate framework (ZIF) membranes consisting of 2-methylimidazolate (ZIF-8 linker) and benzimidazolate (ZIF-7 linker) linkers, termed ZIF-7-8 membranes. The fast-volumetric microwave heating in conjunction with a unique counter diffusion of metal and linker solutions enabled unprecedented rapid synthesis of well-intergrown ZIF-7-8 membranes in ∼90 s, the fastest MOF membrane preparation up to date. Furthermore, we were able to tune the molecular sieving properties of the ZIF-7-8 membranes by varying the benzimidazole-to-2-methylimidazole (bIm-to-mIm) linker ratio in the hybrid frameworks. The tuning of their molecular sieving properties led to the systematic change in the permeance and selectivity of various small gases. The unprecedented rapid synthesis of well-intergrown ZIF-7-8 membranes with tunable molecular sieving properties is an important step forward for the commercial gas separation applications of ZIF membranes.

Poly (ether imide sulfone) membranes from solutions in ionic liquids

KAUST Repository

Kim, Dooli; Nunes, Suzana Pereira

2017-01-01

A membrane manufacture method based on non-volatile solvents and a high performance polymer, poly (ether imide sulfone) (EXTEM™), is proposed, as greener alternative to currently industrial process. We dissolved EXTEM™ in pure ionic liquids: 1-ethyl

The transfer of rare earth elements through liquid extraction membranes

International Nuclear Information System (INIS)

Kapranchik, V.P.; Proyaev, V.V.; Kopyrin, A.A.

1988-01-01

The transfer of rare earth elements through liquid extraction membranes, presenting Dacron nuclear filters, impregnated by extractants of different types (tributylphosphine oxide; di-2-ethylhexylphosphoric acid, HDEHP; trioctylamine, TOA) is investigated. It is ascertained that in systems with extractant-carriers TOA and HDEHP inversion of dependences of flow values and distribution coefficients on the element atomic number is observed. Mathematical model of transfer, permitting to establish relation between extractional and transport characteristics of the membrane, is suggested

Plasmachemical oxidation processes in a hybrid gas-liquid electrical discharge reactor

Energy Technology Data Exchange (ETDEWEB)

Lukes, Petr; Locke, Bruce R [Department of Chemical and Biomedical Engineering, FAMU-FSU College of Engineering, Florida State University, 2525 Pottsdamer Street, Tallahassee, Florida (United States)

2005-11-21

Oxidation processes induced in water by pulsed electrical discharges generated simultaneously in the gas phase in close proximity to the water surface and directly in the liquid were investigated in a hybrid series gas-liquid electrical discharge reactor. The mechanism of phenol degradation was studied through its dependence on the gas phase and liquid phase compositions using pure argon and oxygen atmospheres above the liquid and different initial pH values in the aqueous solution. Phenol degradation was significantly enhanced in the hybrid-series reactor compared with the phenol removal by the single-liquid phase discharge reactor. Under an argon atmosphere the mechanism of phenol degradation was mainly caused by the electrophilic attack of OH{center_dot} radicals produced by the liquid phase discharge directly in water and OH{center_dot} radicals produced by the gas phase discharge at the gas-liquid interface. Under an oxygen atmosphere the formation of gaseous ozone dominated over the formation of OH{center_dot} radicals, and the contribution of the gas phase discharge in this case was determined mainly by the dissolution of gaseous ozone into the water and its subsequent interaction with phenol. At high pH phenol was degraded, in addition to the direct attack by ozone, also through indirect reactions of OH{center_dot} radicals formed via a peroxone process by the decomposition of dissolved ozone by hydrogen peroxide produced by the liquid phase discharge. Such a mechanism was proved by the detection of cis,cis-muconic acid and pH-dependent degradation of phenol, which resulted in significantly higher removal of phenol from alkaline solution observed under oxygen atmosphere than in argon.

Plasmachemical oxidation processes in a hybrid gas-liquid electrical discharge reactor

International Nuclear Information System (INIS)

Lukes, Petr; Locke, Bruce R

2005-01-01

Oxidation processes induced in water by pulsed electrical discharges generated simultaneously in the gas phase in close proximity to the water surface and directly in the liquid were investigated in a hybrid series gas-liquid electrical discharge reactor. The mechanism of phenol degradation was studied through its dependence on the gas phase and liquid phase compositions using pure argon and oxygen atmospheres above the liquid and different initial pH values in the aqueous solution. Phenol degradation was significantly enhanced in the hybrid-series reactor compared with the phenol removal by the single-liquid phase discharge reactor. Under an argon atmosphere the mechanism of phenol degradation was mainly caused by the electrophilic attack of OH· radicals produced by the liquid phase discharge directly in water and OH· radicals produced by the gas phase discharge at the gas-liquid interface. Under an oxygen atmosphere the formation of gaseous ozone dominated over the formation of OH· radicals, and the contribution of the gas phase discharge in this case was determined mainly by the dissolution of gaseous ozone into the water and its subsequent interaction with phenol. At high pH phenol was degraded, in addition to the direct attack by ozone, also through indirect reactions of OH· radicals formed via a peroxone process by the decomposition of dissolved ozone by hydrogen peroxide produced by the liquid phase discharge. Such a mechanism was proved by the detection of cis,cis-muconic acid and pH-dependent degradation of phenol, which resulted in significantly higher removal of phenol from alkaline solution observed under oxygen atmosphere than in argon

Hybrid polymer composite membrane for an electromagnetic (EM) valveless micropump

Science.gov (United States)

Said, Muzalifah Mohd; Yunas, Jumril; Bais, Badariah; Azlan Hamzah, Azrul; Yeop Majlis, Burhanuddin

2017-07-01

In this paper, we report on a hybrid membrane used as an actuator in an electromagnetically driven valveless micropump developed using MEMS processes. The membrane structure consists of the combination of a magnetic polymer composite membrane and an attached bulk permanent magnet which is expected to have a compact structure and a strong magnetic force with maintained membrane flexibility. A soft polymeric material made of polydimethylsiloxane (PDMS) is initially mixed with neodymium magnetic particles (NdFeB) to form a magnetic polymer composite membrane. The membrane is then bonded with the PDMS based microfluidic part, developed using soft lithography process. The developed micropump was tested in terms of the actuator membrane deflection capability and the fluidic flow of the injected fluid sample through the microfluidic channel. The experimental results show that the magnetic composite actuator membrane with an attached bulk permanent magnet is capable of producing a maximum membrane deflection of up to 106 µm. The functionality test of the electromagnetic (EM) actuator for fluid pumping purposes was done by supplying an AC voltage with various amplitudes, signal waves and frequencies. A wide range of sample injection rates from a few µl min-1 to tens of nl min-1 was achieved with a maximum flow rate of 6.6 µl min-1. The injection flow rate of the EM micropump can be controlled by adjusting the voltage amplitude and frequency supplied to the EM coil, to control the membrane deflection in the pump chamber. The designed valveless EM micropump has a very high potential to enhance the drug delivery system capability in biomedical applications.

Nuclide separation modeling through reverse osmosis membranes in radioactive liquid waste

Directory of Open Access Journals (Sweden)

Byung-Sik Lee

2015-12-01

Full Text Available The aim of this work is to investigate the transport mechanism of radioactive nuclides through the reverse osmosis (RO membrane and to estimate its effectiveness for nuclide separation from radioactive liquid waste. An analytical model is developed to simulate the RO separation, and a series of experiments are set up to confirm its estimated separation behavior. The model is based on the extended Nernst–Plank equation, which handles the convective flux, diffusive flux, and electromigration flux under electroneutrality and zero electric current conditions. The distribution coefficient which arises due to ion interactions with the membrane material and the electric potential jump at the membrane interface are included as boundary conditions in solving the equation. A high Peclet approximation is adopted to simplify the calculation, but the effect of concentration polarization is included for a more accurate prediction of separation. Cobalt and cesium are specifically selected for the experiments in order to check the separation mechanism from liquid waste composed of various radioactive nuclides and nonradioactive substances, and the results are compared with the estimated cobalt and cesium rejections of the RO membrane using the model. Experimental and calculated results are shown to be in excellent agreement. The proposed model will be very useful for the prediction of separation behavior of various radioactive nuclides by the RO membrane.

Nuclide separation modeling through reverse osmosis membranes in radioactive liquid waste

Energy Technology Data Exchange (ETDEWEB)

Lee, Byung Sik [KEPCO Engineering and Construction, Gimcheon (Korea, Republic of)

2015-12-15

The aim of this work is to investigate the transport mechanism of radioactive nuclides through the reverse osmosis (RO) membrane and to estimate its effectiveness for nuclide separation from radioactive liquid waste. An analytical model is developed to simulate the RO separation, and a series of experiments are set up to confirm its estimated separation behavior. The model is based on the extended Nernst-Plank equation, which handles the convective flux, diffusive flux, and electromigration flux under electroneutrality and zero electric current conditions. The distribution coefficient which arises due to ion interactions with the membrane material and the electric potential jump at the membrane interface are included as boundary conditions in solving the equation. A high Peclet approximation is adopted to simplify the calculation, but the effect of concentration polarization is included for a more accurate prediction of separation. Cobalt and cesium are specifically selected for the experiments in order to check the separation mechanism from liquid waste composed of various radioactive nuclides and nonradioactive substances, and the results are compared with the estimated cobalt and cesium rejections of the RO membrane using the model. Experimental and calculated results are shown to be in excellent agreement. The proposed model will be very useful for the prediction of separation behavior of various radioactive nuclides by the RO membrane.

Hybridization of plant virus ssRNAs Transferred to Hybond N membrane

International Nuclear Information System (INIS)

Kudela, O.; Kudelova, K.; Plaschke-Jakubik, K.

1998-01-01

In this paper we present a protocol for the non-denaturating agarose gel electrophoresis of plant virus ssRNAs, their blotting onto Hybond N membrane, and hybridization with [alpha 32 P]dNTP-labelled cDNA probe. The protocol is not pretentious on technical equipment, omits denaturation and neutralization steps and some chemical required in other modifications. (authors)

Selective enantioseparation of levocetirizine via a hollow fiber supported liquid membrane and mass transfer prediction

Energy Technology Data Exchange (ETDEWEB)

Sunsandee, Niti [Government Pharmaceutical Organization, Bangkok (Thailand); Leepipatpiboon, Natchanun [Chulalongkorn University, Bangkok (Thailand); Ramakul, Prakorn [Silpakorn University, Nakhon Pathom (Thailand)

2013-06-15

The enantioselective separation of levocetirizine via a hollow fiber supported liquid membrane was examined. O,O'-dibenzoyl-(2R,3R)-tartaric acid ((-)-DBTA) diluted in 1-decanol was used as a chiral selector extractant. The influence of concentrations of feed and stripping phases, and extractant concentration in the membrane phase, was also investigated. A mathematical model focusing on the extraction side of the liquid membrane system was presented to predict the concentration of levocetirizine at different times. The extraction and recovery of levocetirizine from feed phase were 75.00% and 72.00%, respectively. The mass transfer coefficients at aqueous feed boundary layer (k{sub f}) and the organic liquid membrane phase (k{sub m}) were calculated as 2.41x10{sup 2} and 1.89x10{sup 2} cm/s, respectively. The validity of the developed model was evaluated through a comparison with experimental data, and good agreement was obtained.

Effects of alpha-lipoic acids on sperm membrane integrity during liquid storage of boar semen

Directory of Open Access Journals (Sweden)

Laura Parlapan

2015-05-01

Full Text Available Preliminary studies have shown that sperm membrane from swine shows high sensitivity to cryopreservation process, causing a dramatic reduction in sperm quality. This has been attributed to the production of reactive oxygen species, that cause lipid peroxidation in sperm membranes. The aim of the present study was to minimize the oxidative attack by adding different concentration of alpha-lipoic acid into the sperm liquid storage at 17ºC for 7 days. Freshly ejaculated boar semen was diluted with Beltsville Thawing Solution (BTS and supplemented with 5 levels of alpha-lipoic  acid (0.015, 0.02, 0.05, 0.1, 0.15 mmol/ml. The membrane integrity was evaluated at days 0, 1, 3, 5 and 7 of liquid preservation, using flow cytometer FACSCanto II (BD Biociencias systems. The experiment indicate that supplementation of alpha-lipoic  acid to the semen liquid storage extender improve sperm membrane

Mathematical modeling of liquid/liquid hollow fiber membrane contactor accounting for interfacial transport phenomena: Extraction of lanthanides as a surrogate for actinides

International Nuclear Information System (INIS)

Rogers, J.D.

1994-01-01

This report is divided into two parts. The second part is divided into the following sections: experimental protocol; modeling the hollow fiber extractor using film theory; Graetz model of the hollow fiber membrane process; fundamental diffusive-kinetic model; and diffusive liquid membrane device-a rigorous model. The first part is divided into: membrane and membrane process-a concept; metal extraction; kinetics of metal extraction; modeling the membrane contactor; and interfacial phenomenon-boundary conditions-applied to membrane transport

Effect of Cross-Linking on the Mechanical and Thermal Properties of Poly(amidoamine) Dendrimer/Poly(vinyl alcohol) Hybrid Membranes for CO2 Separation.

Science.gov (United States)

Duan, Shuhong; Kai, Teruhiko; Saito, Takashi; Yamazaki, Kota; Ikeda, Kenichi

2014-04-08

Poly(amidoamine) (PAMAM) dendrimers were incorporated into cross-linked poly(vinyl alcohol) (PVA) matrix to improve carbon dioxide (CO2) separation performance at elevated pressures. In our previous studies, PAMAM/PVA hybrid membranes showed high CO2 separation properties from CO2/H2 mixed gases. In this study, three types of organic Ti metal compounds were selected as PVA cross-linkers that were used to prepare PAMAM/cross-linked PVA hybrid membranes. Characterization of the PAMAM/cross-linked PVA hybrid membranes was conducted using nanoindentation and thermogravimetric analyses. The effects of the cross-linker and CO2 partial pressure in the feed gas on CO2 separation performance were discussed. H2O and CO2 sorption of the PAMAM/PVA hybrid membranes were investigated to explain the obtained CO2 separation efficiencies.

The use of supported liquid membranes in the treatment of mining effluents

International Nuclear Information System (INIS)

Hebden, D.; Smit, J.J.

1984-01-01

The acid barren effluents from uranium extraction plants contain a number of dissolved metals although these are often only in trace concentrations. Whilst recovery of these minerals for economic gain has been considered in the past, the removal of some of these minerals is now even more desirable in view of environmental considerations. It is in this application that the supported liquid membrane system finds a model application, with its ability to treat large volumes of unclarified waters, with minimal solvent losses, and selectivity of ion removal. This paper presents current research into this supported liquid membrane application and reviews techniques and costs, in the light of present knowledge. (author)

Performance of cellulose acetate membrane with different additives for palm oil mill effluent (POME) liquid waste treatment

Science.gov (United States)

Aprilia, N. A. S.; Fauzi; Azmi, N.; Najwan, N.; Amin, A.

2018-03-01

Performance of cellulose acetate membrane for treatment of POME liquid has studied with different additives. Cellulose acetate membranes were prepared with different additive ie formamide and polyethylene glycol and used acetone as solvent. The function of formamide and polyethylene glycol (PEG) is to increase the porosity of the membrane surface. Performance of the membrane were included SEM, FT-IR and coefficient permeability. Membrane performance has been performed for percent rejection of total suspended solid (TSS) and turbidity of POME liquid waste. Cellulose acetate with formamide shows an increased percentage of rejection in removing TSS and turbidity than cellulose acetate with PEG.

Membrane interactions of ionic liquids and imidazolium salts.

Science.gov (United States)

Wang, Da; Galla, Hans-Joachim; Drücker, Patrick

2018-06-01

Room-temperature ionic liquids (RTILs) have attracted considerable attention in recent years due to their versatile properties such as negligible volatility, inflammability, high extractive selectivity and thermal stability. In general, RTILs are organic salts with a melting point below ~100 °C determined by the asymmetry of at least one of their ions. Due to their amphiphilic character, strong interactions with biological materials can be expected. However, rising attention has appeared towards their similarity and interaction with biomolecules. By employing structural modifications, the biochemical properties of RTILs can be designed to mimic lipid structures and to tune their hydrophobicity towards a lipophilic behavior. This is evident for the interaction with lipid-membranes where some of these compounds present membrane-disturbing effects or cellular toxicity. Moreover, they can form micelles or lipid-like bilayer structures by themselves. Both aspects, cellular effects and membrane-forming capacities, of a novel class of lipophilic imidazolium salts will be discussed.

Liquid radioactive wastes from hospitals by polymeric membrane

International Nuclear Information System (INIS)

Arnal, J.M.; Sancho, M.; Verdu, G.; Campayo, J.M.

1998-01-01

Streams containing I''125 produced from RIA process, classified as radioactive waste of low activity, are generated by all different treatments applied in IN VITRO techniques. Consequently, an accumulation of solutions containing I''125 is produced in the order of 50-100 L/month approximately. The storage at sanitary centres and the accumulation caused by it creates a serious problem in the hospital. According to the specific activity and the installation spill authorization, one can choose between three ways of handling: direct discharge, temporal storage until the radioactive waste come to decay and then discharged, waste management by the authorised company (ENRESA). If the third way of discharge is applied the treatment of waste using membranes should be considered. Using membranes, important reduction coefficients in volume in the order of 10:1 are obtained. The aim of this work is the declassification of the I''125 solutions as a liquid radioactive waste using membrane techniques. Both, a radioactive concentrated waste and non-contaminated waste are obtained. (Author)

Application of reverse osmosis membrane technology for liquid radioactive waste processing

International Nuclear Information System (INIS)

Zhao Juan

2010-01-01

Liquid radioactive waste (LRW) processing should bear an acceptable level of residual radioactivity for discharge and meet the request of energy saving and waste minimization. Reverse osmosis (RO) membrane technology has been developed as a novel process for LRW processing. Five basic operating parameters of flux, recovery factor, rejection factor, concentration factor and decontamination factor were described, and the latter two parameters were the most important. Concentration factor and decontamination factor should be as high as possible and simultaneously the operating cost for membrane filtration should be low. Technical design considerations for membrane process were discussed and optimized from the aspects of pretreatment, membrane module choice and arrangement and membrane clear out. Application and investigation of RO membrane technology for LRW processing were introduced and it should be noted that the RO membrane technology has been introduced into overseas nuclear power plants for LRW processing and interiorly in the stage of investigation. (authors)

Conductive Hybrid Crystal Composed from Polyoxomolybdate and Deprotonatable Ionic-Liquid Surfactant

Directory of Open Access Journals (Sweden)

Jun Kobayashi

2016-06-01

Full Text Available A polyoxomolybdate inorganic-organic hybrid crystal was synthesized with deprotonatable ionic-liquid surfactant. 1-dodecylimidazolium cation was employed for its synthesis. The hybrid crystal contained δ-type octamolybdate (Mo8 isomer, and possessed alternate stacking of Mo8 monolayers and interdigitated surfactant bilayers. The crystal structure was compared with polyoxomolybdate hybrid crystals comprising 1-dodecyl-3-methylimidazolium surfactant, which preferred β-type Mo8 isomer. The less bulky hydrophilic moiety of the 1-dodecylimidazolium interacted with the δ-Mo8 anion by N–H···O hydrogen bonds, which presumably induced the formation of the δ-Mo8 anion. Anhydrous conductivity of the hybrid crystal was estimated to be 5.5 × 10−6 S·cm−1 at 443 K by alternating current (AC impedance spectroscopy.

Liquid anion exchangers (LAE) as novel receptors for plutonium pertraction across polymer immobilized liquid membranes

International Nuclear Information System (INIS)

Sonawane, J.V.; Anil Kumar; Sawant, S.R.; Singh, R.K.; Bajpai, D.D.; Shukla, J.P.

1999-03-01

The diffusion-limited and amine-facilitated Pu 4+ cation permeation in nitric acid media across a polymer immobilized liquid membrane (PILM) has been investigated to quantify the membrane carrier type effects on its transport. Primene JM-T (JMT) as primary, Amberlite LA-2 (Amb LA-2) as secondary, trilaurylamine (TLA] and triiso-octyl amine (TIOA) as tertiary and Adogen-464 (Ado-464) and Aliquat-336 (Ali-336) as quaternary amines as typical examples of nitrogen containing basic extractants are tested as the carriers. After suitable dilutions, the receptors are immobilized on a microporous polymeric support which are held within the pores by capillary forces. Both the composition of the organic membrane solvents and type of amine carriers exert a marked effect on plutonium permeation. Recovery of Pu steadily increases from primary to quaternary amines; its permeability across PILM roughly follows the order quaternary > tertiary > secondary > primary, similar to that generally observed in liquid-liquid distribution experiments. More than 95% pertraction of Pu(IV) is easily accomplished using tertiary or quaternary amine as ionophores across PILM in single run employing a feed solution containing about 5 mg dm -3 Pu in 4 M nitric acid solution while the receiving phase is 0.1M NH 2 OH.HCl prepared in 0.3M HNO 3 . On the other hand, plutonium permeation at 4M HNO 3 under similar experimental conditions using other types of amines as carriers namely primary amine, Pri JM-T afforded only 19% and 49% by Amb LA-2 in 6-7h runs. Results of the detailed study to evaluate the effect of other contaminants on Pu transport are also discussed. (author)

Bromate formation in a hybrid ozonation-ceramic membrane filtration system.

Science.gov (United States)

Moslemi, Mohammadreza; Davies, Simon H; Masten, Susan J

2011-11-01

The effect of pH, ozone mass injection rate, initial bromide concentration, and membrane molecular weight cut off (MWCO) on bromate formation in a hybrid membrane filtration-ozonation reactor was studied. Decreasing the pH, significantly reduced bromate formation. Bromate formation increased with increasing gaseous ozone mass injection rate, due to increase in dissolved ozone concentrations. Greater initial bromide concentrations resulted in higher bromate concentrations. An increase in the bromate concentration was observed by reducing MWCO, which resulted in a concomitant increase in the retention time in the system. A model to estimate the rate of bromate formation was developed. Good correlation between the model simulation and the experimental data was achieved. Copyright © 2011 Elsevier Ltd. All rights reserved.

Effect of Cross-Linking on the Mechanical and Thermal Properties of Poly(amidoamine Dendrimer/Poly(vinyl alcohol Hybrid Membranes for CO2 Separation

Directory of Open Access Journals (Sweden)

Shuhong Duan

2014-04-01

Full Text Available Poly(amidoamine (PAMAM dendrimers were incorporated into cross-linked poly(vinyl alcohol (PVA matrix to improve carbon dioxide (CO2 separation performance at elevated pressures. In our previous studies, PAMAM/PVA hybrid membranes showed high CO2 separation properties from CO2/H2 mixed gases. In this study, three types of organic Ti metal compounds were selected as PVA cross-linkers that were used to prepare PAMAM/cross-linked PVA hybrid membranes. Characterization of the PAMAM/cross-linked PVA hybrid membranes was conducted using nanoindentation and thermogravimetric analyses. The effects of the cross-linker and CO2 partial pressure in the feed gas on CO2 separation performance were discussed. H2O and CO2 sorption of the PAMAM/PVA hybrid membranes were investigated to explain the obtained CO2 separation efficiencies.

Cone-shaped membrane liquid phase micro extraction

International Nuclear Information System (INIS)

Hong, Heng See; Sanagi, M.M.; Ibrahim, W.A.W.; Naim, A.A.

2008-01-01

A novel sample pre-treatment technique termed cone-shaped membrane liquid phase micro extraction (CSM-LPME) was developed and combined with micro-liquid chromatography (micro-LC) for the determination of selected pesticides in water samples. Several important extraction parameters such as types of extraction solvent, agitation rate, pH value, total exposure time and effect of salt and humic acids were investigated and optimized. Enrichment factors of >50 folds were easily achieved within 20 min of extraction. The new developed method demonstrated an excellent performance in terms of speed, cost effectiveness, reproducibility, as well as exceptional low detection limits. Current work provides a great interest to further investigate on the applicability of the CSM-LPME technique in analytical chemistry and explores the possibility of replacing conventional extraction techniques such as soxhlet, solid phase extraction (SPE) and solid phase micro extraction (SPME). (author)

Ionic Liquids As Self-Assembly Guide for the Formation of Nanostructured Block Copolymer Membranes

KAUST Repository

Madhavan, Poornima; Sougrat, Rachid; Behzad, Ali Reza; Peinemann, Klaus-Viktor; Nunes, Suzana Pereira

2015-01-01

Nanostructured block copolymer membranes were manufactured by water induced phase inversion, using ionic liquids (ILs) as cosolvents. The effect of ionic liquids on the morphology was investigated, by using polystyrene-b-poly(4-vinyl pyridine) (PS

Ionic Liquid Membranes for Carbon Dioxide-Methane Separation

Czech Academy of Sciences Publication Activity Database

Uchytil, Petr; Schauer, Jan; Petričkovič, Roman; Setničková, Kateřina; Suen, S.Y.

2011-01-01

Roč. 383, 1-2 (2011), s. 262-271 ISSN 0376-7388 R&D Projects: GA ČR GA104/09/1165; GA ČR GCP106/10/J038; GA MŠk ME 889 Institutional research plan: CEZ:AV0Z40720504; CEZ:AV0Z40500505 Keywords : ionic liquid membrane * gas separation * gas transport Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 3.850, year: 2011

Olefins-selective asymmetric carbon molecular sieve hollow fiber membranes for hybrid membrane-distillation processes for olefin/paraffin separations

KAUST Repository

Xu, Liren

2012-12-01

In this paper, the development of asymmetric carbon molecular sieve (CMS) hollow fiber membranes and advanced processes for olefin/paraffin separations based on the CMS membranes are reported. Membrane-based olefin/paraffin separations have been pursued extensively over the past decades. CMS membranes are promising to exceed the performance upper bound of polymer materials and have demonstrated excellent stability for gas separations. Previously, a substructure collapse phenomenon was found in Matrimid ® precursor derived CMS fiber. To overcome the permeance loss due to the increased separation layer thickness, 6FDA-DAM and 6FDA/BPDA-DAM precursors were selected as potential new precursors for carbon membrane formation. Defect-free asymmetric 6FDA-DAM and 6FDA/BPDA-DAM hollow fibers were successfully fabricated from a dry-jet/wet-quench spinning process. Polymer rigidity, glass-rubber transition and asymmetric morphology were correlated. CMS hollow fiber membranes produced from 6FDA-polymer precursors showed significant improvement in permeance for ethylene/ethane and propylene/propane separations. Further studies revealed that the CMS membranes are olefins-selective, which means the membranes are able to effectively separate olefins (ethylene and propylene) from paraffins (ethane and propane). This unique feature of CMS materials enables advanced hybrid membrane-distillation process designs. By using the olefins-selective membranes, these new processes may provide advantages over previously proposed retrofitting concepts. Further applications of the membranes are explored for hydrocarbons processes. Significant energy savings and even reduced footprint may be achieved in olefins production units. © 2012 Elsevier B.V.

Designing CNC Knit for Hybrid Membrane And Bending Active Structures

DEFF Research Database (Denmark)

Tamke, Martin; Holden Deleuran, Anders; Gengnagel, Christoph

2015-01-01

specific properties and detailing. CNC knitting with high tenacity yarn enables this practice and offers an alternative to current woven membranes. The design and fabrication of an 8m high fabric tower through an interdisciplinary team of architects, structural and textile engineers, allowed to investigate...... means to design, specify, make and test CNC knit as material for hybrid structures in architectural scale. This paper shares the developed process, identifies challenges, potentials and future work...

Extraction of zirconium from simulated acidic nitrate waste using liquid membrane in hollow fiber contactor

International Nuclear Information System (INIS)

Pandey, G.; Chinchale, R.; Renjith, A.U.; Dixit, S.; Mukhopadhyay, S.; Shenoy, K.T.; Ghosh, S.K.

2015-01-01

The acidic waste raffinate stream of zirconium (Zr) purification plant contains about 2 gpl of Zr in about 2M free nitric acid. TBP, which is the most commonly used solvent in the nuclear industry, is not suitable for the extraction of Zr from this lean solution as its distribution coefficient is less than one. In house synthesized Mixed Alkyl Phosphine Oxide (MAPO) is a potential extractant for Zr from this lean stream. Intensification of this process for recovery of Zr has been attempted through use of efficient contactor, namely, hollow fiber module and efficient process, namely, simultaneous extraction and stripping across liquid membrane containing MAPO. Based on batch equilibrium studies selection of suitable concentration of extractant, composition of diluent, selection and concentration of strippant for the proposed liquid membrane system was made. The selected organic and strippant concentration was used to study suitability of application of Dispersion Liquid Membrane (DLM) in hollow fiber contactor for recovery Zr from solution simulated to Zr plant raffinate. Challenges related to stable operation of the liquid membrane system like stability of the organic phase in the micropores of lumen and stability of the dispersion during the pertraction were addressed through pressure balance across the lumen and choice of adequate dispersion condition respectively. (author)

Dual-Channel, Molecular-Sieving Core/Shell ZIF@MOF Architectures as Engineered Fillers in Hybrid Membranes for Highly Selective CO2 Separation.

Science.gov (United States)

Song, Zhuonan; Qiu, Fen; Zaia, Edmond W; Wang, Zhongying; Kunz, Martin; Guo, Jinghua; Brady, Michael; Mi, Baoxia; Urban, Jeffrey J

2017-11-08

A novel core/shell porous crystalline structure was prepared using a large pore metal organic framework (MOF, UiO-66-NH 2 , pore size, ∼ 0.6 nm) as core surrounded by a small pore zeolitic imidazolate framework (ZIF, ZIF-8, pore size, ∼ 0.4 nm) through a layer-by-layer deposition method and subsequently used as an engineered filler to construct hybrid polysulfone (PSF) membranes for CO 2 capture. Compared to traditional fillers utilizing only one type of porous material with rigid channels (either large or small), our custom designed core/shell fillers possess clear advantages via pore engineering: the large internal channels of the UiO-66-NH 2 MOFs create molecular highways to accelerate molecular transport through the membrane, while the thin shells with small pores (ZIF-8) or even smaller pores generated at the interface by the imperfect registry between the overlapping pores of ZIF and MOF enhance molecular sieving thus serving to distinguish slightly larger N 2 molecules (kinetic diameter, 0.364 nm) from smaller CO 2 molecules (kinetic diameter, 0.33 nm). The resultant core/shell ZIF@MOF and as-prepared hybrid PSF membranes were characterized by transmission electron microscopy, X-ray diffraction, wide-angle X-ray scattering, scanning electron microscopy, Fourier transform infrared, thermogravimetric analysis, differential scanning calorimetry, and contact angle tests. The dependence of the separation performance of the membranes on the MOF/ZIF ratio was also studied by varying the number of layers of ZIF coatings. The integrated PSF-ZIF@MOF hybrid membrane (40 wt % loading) with optimized ZIF coating cycles showed improved hydrophobicity and excellent CO 2 separation performance by simultaneously increasing CO 2 permeability (CO 2 permeability of 45.2 barrer, 710% higher than PSF membrane) and CO 2 /N 2 selectivity (CO 2 /N 2 selectivity of 39, 50% higher than PSF membrane), which is superior to most reported hybrid PSF membranes. The strategy of using

Thermoresponsive Membrane Based on Thermotropic Liquid Crystalline Cholesteryl - (L-lacticacidn System: Study of Its Drug Permeability

Directory of Open Access Journals (Sweden)

Massoumeh Bagheri

2013-01-01

Full Text Available The rapidly increasing interest in functional materials with reversibly switchable physico- chemical properties has led to significant work on the development of stimuli responsive membranes. Thermotropic liquid crystals with their exceptional properties have potentials for drug-delivery applications. Thermoresponsive liquid-crystal-embedded membranes were investigated for the purpose of developing the drug delivery systems with thermal stimuli response. Drug release occurs at temperatures above the phase transition temperature of thermotropic liquid crystals. Therefore, they can control drug release in response to small temperature changes. In this work, the biocompatible and thermotropic liquid crystalline polymer cholesteryl-(L-lactic acidn ,CLAn (n=30, was synthesized with accurate control of molecular weight via ring opening polymerization method. Polymerization of L-lactide was carried out in the presence of cholesterol as an initiator and catalytic amount of tin (II octoate (Sn(Oct2 at 150°C in 5 h. The number-average degree of polymerization of CLA 30 was obtained from 1H NMR spectroscopy. The phase transition behavior of liquid crystalline CLA30 was established by differential scanning calorimetry and polarizing optical microscopy. The resulting liquid crystalline CLA30 was subsequently utilized to prepare CLA30 -embedded cellulose nitrate membrane by adsorption method. The CLA30-embedded cellulose nitrate membrane was used by an in-vitro drug penetration studies. Acetaminophen was used as a model drug. The permeation study was carried out at different temperatures around glass transition temperature of polymer CLA30 (37, 45 and 40°C, respectively. The results show that the CLA30 -embedded cellulose nitrate membranes exhibit thermo-responsive sensitivity with controlled drug permeation.

Integrated pyrolucite fluidized bed-membrane hybrid process for improved iron and manganese control in drinking water.

Science.gov (United States)

Dashtban Kenari, Seyedeh Laleh; Barbeau, Benoit

2017-04-15

Newly developed ceramic membrane technologies offer numerous advantages over the conventional polymeric membranes. This work proposes a new configuration, an integrated pyrolucite fluidized bed (PFB)-ceramic MF/UF hybrid process, for improved iron and manganese control in drinking water. A pilot-scale study was undertaken to evaluate the performance of this process with respect to iron and manganese control as well as membrane fouling. In addition, the fouling of commercially available ceramic membranes in conventional preoxidation-MF/UF process was compared with the hybrid process configuration. In this regard, a series of experiments were conducted under different influent water quality and operating conditions. Fouling mechanisms and reversibility were analyzed using blocking law and resistance-in-series models. The results evidenced that the flux rate and the concentration of calcium and humic acids in the feed water have a substantial impact on the filtration behavior of both membranes. The model for constant flux compressible cake formation well described the rise in transmembrane pressure. The compressibility of the filter cake substantially increased in the presence of 2 mg/L humic acids. The presence of calcium ions caused significant aggregation of manganese dioxide and humic acid which severely impacted the extent of membrane fouling. The PFB pretreatment properly alleviated membrane fouling by removing more than 75% and 95% of iron and manganese, respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Influence of Extractant TOA, Stirring Time on the Extraction ProcessLiquid-liquid, and Liquid Membrane on the Liquid Wastes Containing Cd

International Nuclear Information System (INIS)

Prayitno; Djoko-Sardjono; Nurimaniwati; Adhe-Helmayani

2000-01-01

The influence of extractant and stirring time on the reduction componentcadmium on liquid wastes has been investigated. The method of experimentalused the extraction with liquid membrane emulsion. The parameters to beinvestigated were extractant amount tri-n octylamine (TOA), duration ofstirring time. In this investigated, extractant amount was varied from 5 to25 % (v/v) TOA, duration of stirring time varied from 5 to minutes. Theresult of experimental can be concluded that the best condition obtained forreducing cadmium component was on extractant amount 20 % (v/v) TOA, stirringtime 25 minutes. The best condition for reducing the cadmium component wasefficiency factor 98.35%. (author)

Enhanced ionic liquid mobility induced by confinement in 1D CNT membranes

Science.gov (United States)

Berrod, Q.; Ferdeghini, F.; Judeinstein, P.; Genevaz, N.; Ramos, R.; Fournier, A.; Dijon, J.; Ollivier, J.; Rols, S.; Yu, D.; Mole, R. A.; Zanotti, J.-M.

2016-04-01

Water confined within carbon nanotubes (CNT) exhibits tremendous enhanced transport properties. Here, we extend this result to ionic liquids (IL) confined in vertically aligned CNT membranes. Under confinement, the IL self-diffusion coefficient is increased by a factor 3 compared to its bulk reference. This could lead to high power battery separators.Water confined within carbon nanotubes (CNT) exhibits tremendous enhanced transport properties. Here, we extend this result to ionic liquids (IL) confined in vertically aligned CNT membranes. Under confinement, the IL self-diffusion coefficient is increased by a factor 3 compared to its bulk reference. This could lead to high power battery separators. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr01445c

Pemisahan Unsur Samarium dan Yttrium dari Mineral Tanah Jarang dengan Teknik Membran Cair Berpendukung (Supported Liquid Membrane

Directory of Open Access Journals (Sweden)

Amri Amin

2009-06-01

Full Text Available he increasing use of rare earth elements in high technology industries needs to be supported by developmental work for the separation of elements. The research objective is fiercely attracting and challenging considering the similarity of bath physical and chemical properties among these elements. The rate separation of samarium and yttrium elements using supported liquid membrane has been studied. Polytetrafluoroethylene (PTFE with pore size of 0.45 µm has been used as the membrane and di(2-ethylhexyl phosphate (D2EHP in hexane has been used as a carrier and nitric acid solution has been used as receiving phase. Result of experiments showed that the best separation rate of samarium and yttrium elements could be obtained at feeding phase of pH 3.0, di(2-ethylhexyl phosphate (D2EHP concentration of 0.3 M, agitation rate of 700 rpm, agitation time of 2 hours, and nitric acid and its solution concentrations of 1.0 M and 0.1 M, respectively. At this condition, separation rates of samarium and yttrium were 64.4 and 67.6%, respectively.   Keywords: liquid membrane, rare earth elements, samarium, yttrium

Description of the Gas Transport through Dynamic Liquid Membrane.

Czech Academy of Sciences Publication Activity Database

Uchytil, Petr; Setničková, Kateřina; Tseng, H.-H.; Šíma, Vladimír; Petričkovič, Roman

2017-01-01

Roč. 184, AUG 31 (2017), s. 152-157 ISSN 1383-5866 Grant - others:AV ČR(CZ) MOST-16-04 Program:Bilaterální spolupráce Institutional support: RVO:67985858 Keywords : gas separation * liquid membrane * solurion-diffusion model Subject RIV: CI - Industrial Chemistry, Chemical Engineering OBOR OECD: Chemical process engineering Impact factor: 3.359, year: 2016

Reverse osmosis desalination of chitosan cross-linked graphene oxide/titania hybrid lamellar membranes.

Science.gov (United States)

Deng, Hui; Sun, Penzhan; Zhang, Yingjiu; Zhu, Hongwei

2016-07-08

With excellent mass transport properties, graphene oxide (GO)-based lamellar membranes are believed to have great potential in water desalination. In order to quantify whether GO-based membranes are indeed suitable for reverse osmosis (RO) desalination, three sub-micrometer thick GO-based lamellar membranes: GO-only, reduced GO (RGO)/titania (TO) nanosheets and RGO/TO/chitosan (CTS) are prepared, and their RO desalination performances are evaluated in a home-made RO test apparatus. The photoreduction of GO by TO improves the salt rejection, which increases slowly with the membrane thickness. The RGO/TO/CTS hybrid membranes exhibit higher rejection rates of only about 30% (greater than threefold improvement compared with a GO-only membrane) which is still inferior compared to other commercial RO membranes. The low rejection rates mainly arise from the pressure-induced weakening of the ion-GO interlayer interactions. Despite the advantages of simple, low-cost preparation, high permeability and selectivity of GO-based lamellar membranes, as the current desalination performances are not high enough to afford practical application, there still remains a great challenge to realize high performance separation membranes for water desalination applications.

Covalent Immobilization of Peroxidase onto Hybrid Membranes for the Construction of Optical Biosensor

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Lyubov Yotova

2015-06-01

Full Text Available The aim of this study is to covalently immobilize horse radish peroxidase (HRP onto new hybrid membranes synthesized by the sol-gel method based on silica precursors, dendrimers and cellulose derivatives. This new system will be used for designing biosensor. For investigation of the properties of membranes, HRP was used as a modeling enzyme. Kinetic parameters, pH and temperature optimum were determined, and the structure of the membranes surface was examined. Results showed higher relative and residual activity of HRP immobilized onto membranes with cellulose acetate butyrate with high molecular weight CAB/H. This novel biosensor could offer a simple, cheap and rapid tool with enhanced sensing performance as well as having potentials to find application in medicine, pharmacy, food and process control and environmental monitoring.

Liquid membrane extraction techniques for trace metal analysis and speciation in environmental and biological matrices

Energy Technology Data Exchange (ETDEWEB)

Ndungu, Kuria

1999-04-01

In this thesis, liquid-membrane-based methods for the analysis of trace metal species in samples of environmental and biological origin were developed. By incorporating extracting reagents in the membrane liquid, trace metal ions were selectively separated from humic-rich natural waters and urine samples, prior to their determination using various instrumental techniques. The extractions were performed in closed flow systems thus allowing easy automation of both the sample clean-up and enrichment. An acidic organophosphorus reagent (DEHPA) and a basic tetraalkylammonium reagent (Aliquat-336) were used as extractants in the membrane liquid to selectively extract and enrich cationic and anionic metal species respectively. A speciation method for chromium species was developed that allowed the determination of cationic Cr(III) species and anionic CR(VI) species in natural water samples without the need of a chromatographic separation step prior to their detection. SLM was also coupled on-line to potentiometric stripping analysis providing a fast and sensitive method for analysis of Pb in urine samples. A microporous membrane liquid-liquid extraction (MMLLE) method was developed for the determination of organotin compounds in natural waters that reduced the number of manual steps involved in the LLE of organotin compounds prior to their CC separation. Clean extracts obtained after running unfiltered humic-rich river water samples through the MMLLE flow system allowed selective determination of all the organotin compounds in a single run using GC-MS in the selected ion monitoring mode (SIM) 171 refs, 9 figs, 4 tabs

Enhanced Proton Conductivity of Sulfonated Hybrid Poly(arylene ether ketone) Membranes by Incorporating an Amino-Sulfo Bifunctionalized Metal-Organic Framework for Direct Methanol Fuel Cells.

Science.gov (United States)

Ru, Chunyu; Li, Zhenhua; Zhao, Chengji; Duan, Yuting; Zhuang, Zhuang; Bu, Fanzhe; Na, Hui

2018-03-07

Novel side-chain-type sulfonated poly(arylene ether ketone) (SNF-PAEK) containing naphthalene and fluorine moieties on the main chain was prepared in this work, and a new amino-sulfo-bifunctionalized metal-organic framework (MNS, short for MIL-101-NH 2 -SO 3 H) was synthesized via a hydrothermal technology and postmodification. Then, MNS was incorporated into a SNF-PAEK matrix as an inorganic nanofiller to prepare a series of organic-inorganic hybrid membranes (MNS@SNF-PAEK-XX). The mechanical property, methanol resistance, electrochemistry, and other properties of MNS@SNF-PAEK-XX hybrid membranes were characterized in detail. We found that the mechanical strength and methanol resistances of these hybrid membranes were improved by the formation of an ionic cross-linking structure between -NH 2 of MNS and -SO 3 H on the side chain of SNF-PAEK. Particularly, the proton conductivity of these hybrid membranes increased obviously after the addition of MNS. MNS@SNF-PAEK-3% exhibited the proton conductivity of 0.192 S·cm -1 , which was much higher than those of the pristine membrane (0.145 S·cm -1 ) and recast Nafion (0.134 S·cm -1 ) at 80 °C. This result indicated that bifunctionalized MNS rearranged the microstructure of hybrid membranes, which could accelerate the transfer of protons. The hybrid membrane (MNS@SNF-PAEK-3%) showed a better direct methanol fuel cell performance with a higher peak power density of 125.7 mW/cm 2 at 80 °C and a higher open-circuit voltage (0.839 V) than the pristine membrane.

A hybrid system of a membrane oscillator coupled to ultracold atoms

Science.gov (United States)

Kampschulte, Tobias

2015-05-01

The control over micro- and nanomechanical oscillators has recently made impressive progress. First experiments demonstrated ground-state cooling and single-phonon control of high-frequency oscillators using cryogenic cooling and techniques of cavity optomechanics. Coupling engineered mechanical structures to microscopic quantum system with good coherence properties offers new possibilities for quantum control of mechanical vibrations, precision sensing and quantum-level signal transduction. Ultracold atoms are an attractive choice for such hybrid systems: Mechanical can either be coupled to the motional state of trapped atoms, which can routinely be ground-state cooled, or to the internal states, for which a toolbox of coherent manipulation and detection exists. Furthermore, atomic collective states with non-classical properties can be exploited to infer the mechanical motion with reduced quantum noise. Here we use trapped ultracold atoms to sympathetically cool the fundamental vibrational mode of a Si3N4 membrane. The coupling of membrane and atomic motion is mediated by laser light over a macroscopic distance and enhanced by an optical cavity around the membrane. The observed cooling of the membrane from room temperature to 650 +/- 230 mK shows that our hybrid mechanical-atomic system operates at a large cooperativity. Our scheme could provide ground-state cooling and quantum control of low-frequency oscillators such as levitated nanoparticles, in a regime where purely optomechanical techniques cannot reach the ground state. Furthermore, we will present a scheme where an optomechanical system is coupled to internal states of ultracold atoms. The mechanical motion is translated into a polarization rotation which drives Raman transitions between atomic ground states. Compared to the motional-state coupling, the new scheme enables to couple atoms to high-frequency structures such as optomechanical crystals.

Hierarchically structured transparent hybrid membranes by in situ growth of mesostructured organosilica in host polymer

Science.gov (United States)

Vallé, Karine; Belleville, Philippe; Pereira, Franck; Sanchez, Clément

2006-02-01

The elaborate performances characterizing natural materials result from functional hierarchical constructions at scales ranging from nanometres to millimetres, each construction allowing the material to fit the physical or chemical demands occurring at these different levels. Hierarchically structured materials start to demonstrate a high input in numerous promising applied domains such as sensors, catalysis, optics, fuel cells, smart biologic and cosmetic vectors. In particular, hierarchical hybrid materials permit the accommodation of a maximum of elementary functions in a small volume, thereby optimizing complementary possibilities and properties between inorganic and organic components. The reported strategies combine sol-gel chemistry, self-assembly routes using templates that tune the material's architecture and texture with the use of larger inorganic, organic or biological templates such as latex, organogelator-derived fibres, nanolithographic techniques or controlled phase separation. We propose an approach to forming transparent hierarchical hybrid functionalized membranes using in situ generation of mesostructured hybrid phases inside a non-porogenic hydrophobic polymeric host matrix. We demonstrate that the control of the multiple affinities existing between organic and inorganic components allows us to design the length-scale partitioning of hybrid nanomaterials with tuned functionalities and desirable size organization from ångström to centimetre. After functionalization of the mesoporous hybrid silica component, the resulting membranes have good ionic conductivity offering interesting perspectives for the design of solid electrolytes, fuel cells and other ion-transport microdevices.

Hybrid Electrostatic/Flextensional Deformable Membrane Mirror for Lightweight, Large Aperture and Cryogenic Space Telescopes, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — TRS Technologies proposes innovative hybrid electrostatic/flextensional membrane deformable mirror capable of large amplitude aberration correction for large...

Flexible Hybrid Membranes with Ni(OH)2 Nanoplatelets Vertically Grown on Electrospun Carbon Nanofibers for High-Performance Supercapacitors.

Science.gov (United States)

Zhang, Longsheng; Ding, Qianwei; Huang, Yunpeng; Gu, Huahao; Miao, Yue-E; Liu, Tianxi

2015-10-14

The practical applications of transition metal oxides and hydroxides for supercapacitors are restricted by their intrinsic poor conductivity, large volumetric expansion, and rapid capacitance fading upon cycling, which can be solved by optimizing these materials to nanostructures and confining them within conductive carbonaceous frameworks. In this work, flexible hybrid membranes with ultrathin Ni(OH)2 nanoplatelets vertically and uniformly anchored on the electrospun carbon nanofibers (CNF) have been facilely prepared as electrode materials for supercapacitors. The Ni(OH)2/CNF hybrid membranes with three-dimensional macroporous architectures as well as hierarchical nanostructures can provide open and continuous channels for rapid diffusion of electrolyte to access the electrochemically active Ni(OH)2 nanoplatelets. Moreover, the carbon nanofiber can act both as a conductive core to provide efficient transport of electrons for fast Faradaic redox reactions of the Ni(OH)2 sheath, and as a buffering matrix to mitigate the local volumetric expansion/contraction upon long-term cycling. As a consequence, the optimized Ni(OH)2/CNF hybrid membrane exhibits a high specific capacitance of 2523 F g(-1) (based on the mass of Ni(OH)2, that is 701 F g(-1) based on the total mass) at a scan rate of 5 mV s(-1). The Ni(OH)2/CNF hybrid membranes with high mechanical flexibility, superior electrical conductivity, and remarkably improved electrochemical capacitance are condsidered as promising flexible electrode materials for high-performance supercapacitors.

Foam films as thin liquid gas separation membranes.

Science.gov (United States)

Ramanathan, Muruganathan; Müller, Hans Joachim; Möhwald, Helmuth; Krastev, Rumen

2011-03-01

In this letter, we testify the feasibility of using freestanding foam films as a thin liquid gas separation membrane. Diminishing bubble method was used as a tool to measure the permeability of pure gases like argon, nitrogen, and oxygen in addition to atmospheric air. All components of the foam film including the nature of the tail (fluorocarbon vs hydrocarbon), charge on the headgroup (anionic, cationic, and nonionic) and the thickness of the water core (Newton black film vs Common black film) were systematically varied to understand the permeation phenomena of pure gases. Overall results indicate that the permeability values for different gases are in accordance with magnitude of their molecular diameter. A smaller gaseous molecule permeates faster than the larger ones, indicating a new realm of application for foam films as size selective separation membranes.

Enhanced electrocatalytic activity of reduced graphene oxide-Os nanoparticle hybrid films obtained at a liquid/liquid interface

Science.gov (United States)

Bramhaiah, K.; Pandey, Indu; Singh, Vidya N.; Kavitha, C.; John, Neena S.

2018-03-01

Hybrid films of reduced graphene oxide-osmium nanoparticles (rGO-Os NPs) synthesized at a liquid/liquid interface are explored for their electrocatalytic activity towards the oxidation of rhodamine B (RhB), a popular colourant found in textile industry effluents and a non-permitted food colour. The free-standing nature of the films enables them to be lifted directly on to electrodes without the aid of any binders. The films consist of aggregates of ultra-small Os NPs interspersed with rGO layers. The hybrid film exhibits enhanced RhB oxidation when compared to its constituents arising from the synergic effect between rGO and Os NPs, Os contributing to electrocatalysis and rGO contributing to high surface area and conductance as well as stabilization of Os nanoparticles. The electrochemical sensor based on rGO-Os NP hybrid film on pencil graphite electrode shows a remarkable performance for the quantitative detection of RhB with a linear variation in a wide range of concentrations, 4-1300 ppb (8.3 nM-2.71 μM). The modified electrode presents good stability over more than 6 months, reproducibility and anti-interference capability. The use of developed sensor for adequate detection of RhB in real samples such as food samples and pen markers is also demonstrated.

Ionic Liquid Confined in Mesoporous Polymer Membrane with Improved Stability for CO2/N2 Separation

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Ming Tan

2017-09-01

Full Text Available Supported ionic liquid membranes (SILMs have a promising prospect of application in flue gas separation, owing to its high permeability and selectivity of CO2. However, existing SILMs have the disadvantage of poor stability due to the loss of ionic liquid from the large pores of the macroporous support. In this study, a novel SILM with high stability was developed by confining ionic liquid in a mesoporous polymer membrane. First, a mesoporous polymer membrane derived from a soluble, low-molecular-weight phenolic resin precursor was deposited on a porous Al2O3 support, and then 1-ethyl-3-methylimidazolium tetrafluoroborate ([emim][BF4] was immobilized inside mesopores of phenolic resin, forming the SILM under vacuum. Effects of trans-membrane pressure difference on the SILM separation performance were investigated by measuring the permeances of CO2 and N2. The SILM exhibits a high ideal CO2/N2 selectivity of 40, and an actual selectivity of approximately 25 in a mixed gas (50% CO2 and 50% N2 at a trans-membrane pressure difference of 2.5 bar. Compared to [emim][BF4] supported by polyethersulfone membrane with a pore size of around 0.45 μm, the [emim][BF4] confined in a mesoporous polymer membrane exhibits an improved stability, and its separation performance remained stable for 40 h under a trans-membrane pressure difference of 1.5 bar in a mixed gas before the measurement was intentionally stopped.

Hybrid gas separation membranes containing star-shaped polystyrene with the fullerene (C60) core

Czech Academy of Sciences Publication Activity Database

Pulyalina, A. Y.; Rostovtseva, V. A.; Pientka, Zbyněk; Vinogradova, L. V.; Polotskaya, G. A.

2018-01-01

Roč. 58, č. 4 (2018), s. 296-303 ISSN 0965-5441 Institutional support: RVO:61389013 Keywords : gas separation * hybrid membranes * star-shaped macromolecules Subject RIV: CD - Macromolecular Chemistry OBOR OECD: Polymer science Impact factor: 0.493, year: 2016

Metal nanoparticles/ionic liquid/cellulose: polymeric membrane for hydrogenation reactions

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Marcos Alexandre Gelesky

2014-01-01

Full Text Available Rhodium and platinum nanoparticles were supported in polymeric membranes with 10, 20 and 40 µm thickness. The polymeric membranes were prepared combining cellulose acetate and the ionic liquid (IL 1-n-butyl-3-methylimidazolium bis(trifluoromethane sulfonylimide (BMI.(NTf2. The presence of metal nanoparticles induced an increase in the polymeric membrane surface areas. The increase of the IL content resulted in an improvement of elasticity and decrease in tenacity and toughness, whereas the stress at break was not affected. The presence of IL probably causes an increase in the separation between the cellulose molecules that result in a higher flexibility and processability of the polymeric membrane. The CA/IL/M(0 combinations exhibit an excellent synergistic effect that enhances the activity and durability of the catalyst for the hydrogenation of cyclohexene. The CA/IL/M(0 polymeric membrane displays higher catalytic activity (up to 7.353 h-1 for the 20 mm of CA/IL/Pt(0 and stability than the nanoparticles dispersed only in the IL.

Fabrication of Mesoporous Silica/Alumina Hybrid Membrane Film Nanocomposites using Template Sol-Gel Synthesis of Amphiphilic Triphenylene

Science.gov (United States)

Lintang, H. O.; Jalani, M. A.; Yuliati, L.; Salleh, M. M.

2017-05-01

Herein we reported that by introducing a one-dimensional (1D) substrate with a porous structure such as anodic aluminum oxide (AAO) membrane, mesoporous silica/alumina hybrid nanocomposites were successfully fabricated by using amphiphilic triphenylene (TPC10TEG) as a template in sol-gel synthesis (TPC10TEG/silicahex). For the optical study of the nanocomposites, TPC10TEG/silicahex showed absorption peak at 264 nm due to the ordered and long-range π-π stacking of the disc-like aromatic triphenylene core. Moreover, the hexagonal arrangement of TPC10TEG/silicahex was proven based on their diffraction peaks of d 100 and d 200 at 2θ = 2.52° and 5.04° and images of transmission electron microscopy (TEM), respectively. For fabrication of mesoporous silica/alumina hybrid membrane, TPC10TEG/silicahex was drop-casted onto AAO membrane for penetration into the porous structure via gravity. X-ray diffraction (XRD) analysis on the resulted hybrid nanocomposites showed that the diffraction peaks of d 100 and d 200 of TPC10TEG/silicahex were still preserved, indicating that the hexagonal arrangements of mesoporous silica were maintained even on AAO substrate. The morphology study on the hybrid nanocomposites using TEM, scanning electron microscope (SEM) and field emission scanning electron microscope (FE-SEM) showed the successful filling of most AAO channels with the TPC10TEG/silicahex nanocomposites.

Polymerizable Ionic Liquid Crystals Comprising Polyoxometalate Clusters toward Inorganic-Organic Hybrid Solid Electrolytes

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Takeru Ito

2017-07-01

Full Text Available Solid electrolytes are crucial materials for lithium-ion or fuel-cell battery technology due to their structural stability and easiness for handling. Emergence of high conductivity in solid electrolytes requires precise control of the composition and structure. A promising strategy toward highly-conductive solid electrolytes is employing a thermally-stable inorganic component and a structurally-flexible organic moiety to construct inorganic-organic hybrid materials. Ionic liquids as the organic component will be advantageous for the emergence of high conductivity, and polyoxometalate, such as heteropolyacids, are well-known as inorganic proton conductors. Here, newly-designed ionic liquid imidazolium cations, having a polymerizable methacryl group (denoted as MAImC1, were successfully hybridized with heteropolyanions of [PW12O40]3− (PW12 to form inorganic-organic hybrid monomers of MAImC1-PW12. The synthetic procedure of MAImC1-PW12 was a simple ion-exchange reaction, being generally applicable to several polyoxometalates, in principle. MAImC1-PW12 was obtained as single crystals, and its molecular and crystal structures were clearly revealed. Additionally, the hybrid monomer of MAImC1-PW12 was polymerized by a radical polymerization using AIBN as an initiator. Some of the resulting inorganic-organic hybrid polymers exhibited conductivity of 10−4 S·cm−1 order under humidified conditions at 313 K.

Effects of temperature and anion species on CO2 permeability and CO2/N2 separation coefficient through ionic liquid membranes

International Nuclear Information System (INIS)

Jindaratsamee, Pinyarat; Shimoyama, Yusuke; Morizaki, Hironobu; Ito, Akira

2011-01-01

The permeability of carbon dioxide (CO 2 ) through imidazolium-based ionic liquid membranes was measured by a sweep gas method. Six species of ionic liquids were studied in this work as follows: [emim][BF 4 ], [bmim][BF 4 ], [bmim][PF 6 ], [bmim][Tf 2 N], [bmim][OTf], and [bmim][dca]. The ionic liquids were supported with a polyvinylidene fluoride porous membrane. The measurements were performed at T = (303.15 to 343.15) K. The partial pressure difference between feed and permeate sides was 0.121 MPa. The permeability of the CO 2 increases with temperature for the all ionic liquid species. Base on solution diffusion theory, it can be explained that the diffusion coefficient of CO 2 in an ionic liquid affects the temperature dependence more strongly than the solubility coefficient. The greatest permeability was obtained with the [bmim][Tf 2 N] membrane. The membrane of [bmim][PF 6 ] presents the lowest permeability. The separation coefficient between CO 2 and N 2 through the ionic liquid membranes was also investigated at the volume fraction of CO 2 at feed side 0.10. The separation coefficient decreases with the increase of temperature for the all ionic liquid species. The membrane of [emim][BF 4 ] and [bmim][BF 4 ] gives the highest separation coefficient at constant temperature. The lowest separation coefficient was obtained from [bmim][Tf 2 N] membrane which presents the highest permeability of CO 2 .

Functionalized copolyimide membranes for the separation of gaseous and liquid mixtures

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Nadine Schmeling

2010-08-01

Full Text Available Functionalized copolyimides continue to attract much attention as membrane materials because they can fulfill the demands for industrial applications. Thus not only good separation characteristics but also high temperature stability and chemical resistance are required. Furthermore, it is very important that membrane materials are resistant to plasticization since it has been shown that this phenomenon leads to a significant increase in permeability with a dramatic loss in selectivity. Plasticization effects occur with most polymer membranes at high CO2 concentrations and pressures, respectively. Plasticization effects are also observed with higher hydrocarbons such as propylene, propane, aromatics or sulfur containing aromatics. Unfortunately, these components are present in mixtures of high commercial relevance and can be separated economically by single membrane units or hybrid processes where conventional separation units are combined with membrane-based processes. In this paper the advantages of carboxy group containing 6FDA (4,4′-hexafluoroisopropylidene diphthalic anhydride -copolyimides are discussed based on the experimental results for non cross-linked, ionically and covalently cross-linked membrane materials with respect to the separation of olefins/paraffins, e.g. propylene/propane, aromatic/aliphatic separation e.g. benzene/cyclohexane as well as high pressure gas separations, e.g. CO2/CH4 mixtures. In addition, opportunities for implementing the membrane units in conventional separation processes are discussed.

Optimized permeation and antifouling of PVDF hybrid ultrafiltration membranes: synergistic effect of dispersion and migration for fluorinated graphene oxide

Science.gov (United States)

Li, Mingming; Shi, Jie; Chen, Cheng; Li, Nan; Xu, Zhiwei; Li, Jing; Lv, Hanming; Qian, Xiaoming; Jiao, Xiaoning

2017-03-01

Nanoparticles may have suffered from low modification efficiency in hybrid membranes due to embedding and aggregating in polymer matrix. In order to analyze the modification mechanisms of nanoparticle migration and dispersion on the properties of hybrid membranes, we designed different F/ O ratios ( R F/ O ) of fluorinated graphene oxide (FGO, diameter = 1.5 17.5 μm) by carbon tetrafluoride (CF4) plasma treatment GO for 3, 5, 10, 15, and 20 min and successfully prepared novel PVDF hybrid membranes containing FGO via the phase inversion method. After a prolonged plasma treatment, the R F/ O of FGO was enhanced sharply, indicating an increasing compatibility of FGO with the matrix, especially FGO-20 (GO treated for 20 min). FGO contents in the top layer, sublayer, and the whole of membranes were probed by X-ray photoelectron spectroscopy, energy-dispersive spectrometer, and indirect computation, respectively. In the top layer of membranes, FGO contents declined from 13.14 wt% (PVDF/GO) to 4.00 wt% (PVDF/FGO-10) and 1.96 wt% (PVDF/FGO-20) due to the reduced migration ability of FGO. It is worth mentioning that PVDF/FGO-10 membranes exhibited an excellent water flux and flux recovery rate (up to 406.90 L m-2 h-1 and 88.9%), which were improved by 67.3% and 14.6% and 52.5% and 24.0% compared with those of PVDF/GO and PVDF/FGO-20 membranes, respectively, although the dispersion and migration ability of FGO-10 was maintained at a moderate level. It indicated that the migration and dispersion of FGO in membranes could result in dynamic equilibrium, which played a key role in making the best use of nanomaterials to optimize membrane performance.

Optimized permeation and antifouling of PVDF hybrid ultrafiltration membranes: synergistic effect of dispersion and migration for fluorinated graphene oxide

Energy Technology Data Exchange (ETDEWEB)

Li, Mingming; Shi, Jie; Chen, Cheng; Li, Nan; Xu, Zhiwei, E-mail: xuzhiwei@tjpu.edu.cn; Li, Jing; Lv, Hanming; Qian, Xiaoming, E-mail: qianxiaoming@tjpu.edu.cn; Jiao, Xiaoning [Tianjin Polytechnic University, State Key Laboratory of Separation Membranes and Membrane Processes, School of Textiles (China)

2017-03-15

Nanoparticles may have suffered from low modification efficiency in hybrid membranes due to embedding and aggregating in polymer matrix. In order to analyze the modification mechanisms of nanoparticle migration and dispersion on the properties of hybrid membranes, we designed different F/O ratios (R{sub F/O}) of fluorinated graphene oxide (FGO, diameter = 1.5 ~ 17.5 μm) by carbon tetrafluoride (CF{sub 4}) plasma treatment GO for 3, 5, 10, 15, and 20 min and successfully prepared novel PVDF hybrid membranes containing FGO via the phase inversion method. After a prolonged plasma treatment, the R{sub F/O} of FGO was enhanced sharply, indicating an increasing compatibility of FGO with the matrix, especially FGO-20 (GO treated for 20 min). FGO contents in the top layer, sublayer, and the whole of membranes were probed by X-ray photoelectron spectroscopy, energy-dispersive spectrometer, and indirect computation, respectively. In the top layer of membranes, FGO contents declined from 13.14 wt% (PVDF/GO) to 4.00 wt% (PVDF/FGO-10) and 1.96 wt% (PVDF/FGO-20) due to the reduced migration ability of FGO. It is worth mentioning that PVDF/FGO-10 membranes exhibited an excellent water flux and flux recovery rate (up to 406.90 L m{sup −2} h{sup −1} and 88.9%), which were improved by 67.3% and 14.6% and 52.5% and 24.0% compared with those of PVDF/GO and PVDF/FGO-20 membranes, respectively, although the dispersion and migration ability of FGO-10 was maintained at a moderate level. It indicated that the migration and dispersion of FGO in membranes could result in dynamic equilibrium, which played a key role in making the best use of nanomaterials to optimize membrane performance.

Synthesis, Characterization, and Impregnation of Some Ionic Liquids on Polymer Membrane for Separation of Carbon Dioxide from Its Mixture with Methane

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T. T. L. Bui

2018-03-01

Full Text Available Some 1-alkyl-3-methylimidazolium-based ionic liquids were synthesized, characterized, and immobilized on membranes to form supported ionic liquid membranes. The supported ionic liquid membranes were characterized by SEM. The initial transmembrane pressures were investigated for each type of impregnated membrane. The CO2/CH4 single gas and mixed gas permeability (CO2 and CH4 have been investigated. The results showed that the CO2/CH4 ideal selectivities and mixed gas selectivities reached 15.45 – 23.9 and 13.91 – 22.82, respectively (equivalent to separation yields of 93.3 – 95.98 %.mThe 1-alkyl-3-methylimidazolium acetate impregnated membrane leads to a slightly lowermCO2/CH4 selectivity, however, this ionic liquid is stable, free of halogen and has a low price. The impregnated membranes prepared from polyvinylidene fluoride are more stablemthan those from polyethersulfone support, and have a higher affinity for CO2 compared to other gas. The obtained high CO2/CH4 selectivities indicate that immobilized membranes can be used for CO2 separation processes.

Development of advanced membrane process for treatment of radioactive liquid wastes

International Nuclear Information System (INIS)

Lee, Kune Woo; Choi, W. K.; Lee, J. W.; Jung, G. H.

2002-01-01

The followings were studied through the project entitled 'Development of advanced membrane process for treatment of radioactive liquid wastes'. 1. Surface modification technique of microfiltration membrane. Microporous hydrophobic polypropylene(PP) membrane were modified by radiation-induced grafting using hydrophilic monomers such as arylic acid(AAc), 2-hydroxyethyl methacrylate(HEMA) and styrenesulfonic acid(SSS). The effect of grafting conditions was investigated. Also, copolymeric condition of AAc and EGDMA for nylon membrane was studied. The structure of grafted PP membrane was examined by using FTIR-ATR spectroscopy, SEM and contact angle. The grafted membrane was characterized by measureing the water flux, the ion exchange capacity or the binding capacity of the metal ions. A study on the permeation behavior of simulated waste water containing oil emulsion and characterization of membrane fouling was carried out in the crossflow membrane filtration process using capillary type PP microfiltration membrane modified by radiation induced grafting of HEMA. The effects of various operating parameters were investigated. 2. Electrofiltration Technology. In this section, the process conditions for fouling prevention of membrane by evaluating the effects of operational parameters such as external electric field strength, crossflow velocity, transmembrane pressure, etc. on the permeate flux in electrofiltration were established and the process applicability for oil emulsion wastes containing surfactant using parallel plate type electrofiltration module was evaluated

Development of advanced membrane process for treatment of radioactive liquid wastes

Energy Technology Data Exchange (ETDEWEB)

Lee, Kune Woo; Choi, W. K.; Lee, J. W.; Jung, G. H

2002-01-01

The followings were studied through the project entitled 'Development of advanced membrane process for treatment of radioactive liquid wastes'. 1. Surface modification technique of microfiltration membrane. Microporous hydrophobic polypropylene(PP) membrane were modified by radiation-induced grafting using hydrophilic monomers such as arylic acid(AAc), 2-hydroxyethyl methacrylate(HEMA) and styrenesulfonic acid(SSS). The effect of grafting conditions was investigated. Also, copolymeric condition of AAc and EGDMA for nylon membrane was studied. The structure of grafted PP membrane was examined by using FTIR-ATR spectroscopy, SEM and contact angle. The grafted membrane was characterized by measureing the water flux, the ion exchange capacity or the binding capacity of the metal ions. A study on the permeation behavior of simulated waste water containing oil emulsion and characterization of membrane fouling was carried out in the crossflow membrane filtration process using capillary type PP microfiltration membrane modified by radiation induced grafting of HEMA. The effects of various operating parameters were investigated. 2. Electrofiltration Technology. In this section, the process conditions for fouling prevention of membrane by evaluating the effects of operational parameters such as external electric field strength, crossflow velocity, transmembrane pressure, etc. on the permeate flux in electrofiltration were established and the process applicability for oil emulsion wastes containing surfactant using parallel plate type electrofiltration module was evaluated.

Characterization of Selected Parameters of Organic-Inorganic Hybrid Membranes Based on Various Polymers and Nd-Fe-B Fillers

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Rybak A.

2016-12-01

Full Text Available In this paper magnetic organic-inorganic hybrid membranes based on EC, PPO polymer matrices and various magnetic powder microparticles were synthesized and studied. Constant pressure permeation technique and the Time Lag method were used to obtain the gas transport coefficients. The mechanical, rheological and magnetic parameters of magnetic hybrid membranes were examined. It was found that their separation and gas transport properties (D, P, S and α were improved with the decrease in powder particle size and the increase of membrane’s remanence, saturation magnetization and magnetic particle filling. The increase of the magnetic powder addition and a decrease of its granulation improved also mechanical and rheological parameters of the tested membranes. This improvement also had a positive effect on their gas separation properties and their potential usage in the future.

In-situ Non-Invasive Imaging of Liquid-Immersed Thin Film Composite Membranes

KAUST Repository

Ogieglo, Wojciech; Pinnau, Ingo; Wessling, Matthias

2017-01-01

We present a non-invasive method to directly image liquid-immersed thin film composite membranes. The approach allows accessing information not only on the lateral distribution of the coating thickness, including variations in its swelling

Facile fabrication of ultrathin hybrid membrane for highly flexible supercapacitors via in-situ phase separation of polyethersulfone

Science.gov (United States)

Zhao, Xiaoning; Ran, Fen; Shen, Kuiwen; Yang, Yunlong; Wu, Jiayu; Niu, Xiaoqin; Kong, Lingbin; Kang, Long; Chen, Shaowei

2016-10-01

In this article, a facile method based on in-situ phase-separation was developed for the fabrication of ultrathin hybrid membranes for highly flexible supercapacitors. The structures and morphologies of the prepared electrodes were characterized by scanning electron microscopy (SEM), Fourier-transformed infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA) measurements; and the electrochemical behaviors were examined in 2 M KOH solution. SEM and FTIR characterizations reveal that activated carbon was imbedded into the polymer membrane of polyethersulfone to form a uniform and flexible hybrid membrane. When the thin polymer-carbon membrane (PCM) was used as an electrode material for supercapacitor, a high specific capacitance of 169.4 Fg-1 was obtained at a current density of 0.5 Ag-1 along with good long-term cycle life of 94.6% capacity retention after 2000 charging-discharging cycles. Benefiting from these merits, the as-fabricated PCM//PCM cell shows an excellent electrochemical property. These results suggest a promising route towards the fabrication of highly flexible electrodes for high-performance supercapacitors.

Composites of ionic liquid and amine-modified SAPO 34 improve CO2 separation of CO2-selective polymer membranes

Science.gov (United States)

Hu, Leiqing; Cheng, Jun; Li, Yannan; Liu, Jianzhong; Zhang, Li; Zhou, Junhu; Cen, Kefa

2017-07-01

Mixed matrix membranes with ionic liquids and molecular sieve particles had high CO2 permeabilities, but CO2 separation from small gas molecules such as H2 was dissatisfied because of bad interfacial interaction between ionic liquid and molecular sieve particles. To solve that, amine groups were introduced to modify surface of molecular sieve particles before loading with ionic liquid. SAPO 34 was adopted as the original filler, and four mixed matrix membranes with different fillers were prepared on the outer surface of ceramic hollow fibers. Both surface voids and hard agglomerations disappeared, and the surface became smooth after SAPO 34 was modified by amine groups and ionic liquid [P66614][2-Op]. Mixed matrix membranes with composites of amine-modified SAPO 34 and ionic liquid exhibited excellent CO2 permeability (408.9 Barrers) and CO2/H2 selectivity (22.1).

A study of new anhydrous, conducting membranes based on composites of aprotic ionic liquid and cross-linked SPEEK for fuel cell application

International Nuclear Information System (INIS)

Malik, Rajender Singh; Verma, Pawan; Choudhary, Veena

2015-01-01

Highlights: • New composite membranes based on SPEEK/EG/IL were fabricated. • Composite membranes exhibit good thermal stability than neat SPEEK and XSPEEK membrane. • Proton conductivity of all composite membranes increased with temperature and amount of ionic liquid. • Proton conductivity was measured under anhydrous condition in the temperature ranging from 30–140 °C. - Abstract: The present study describe the preparation and characterisation of anhydrous proton conducting composite membranes based on sulfonated poly(ether ether ketone) [SPEEK–degree of sulfonation 70–72%]/ethylene glycol [EG]/ionic liquid by solution casting method using water: ethanol (50:50) as solvent. For this purpose several composite membranes were prepared by mixing solution of SPEEK/ethylene glycol (67:33 wt %) in water:ethanol with varying amounts of 1-butyl-3-methyl-imidazolium trifluromethanesulfonate [bmim][OTf] ionic liquid. The cross-linking of SPEEK was carried out by thermal treatment i.e. by heating in vacuum oven at 80 °C (2 h), 100 °C (2 h), 120 °C (2 h) and 135 °C for 16 h. Ethylene glycol was used as a cross-linker for SPEEK to reduce the leaching out of ionic liquid and enhance the mechanical strength of SPEEK membranes. The membranes were characterized for thermal [thermogravimetry analysis], structural [FTIR–ATR], proton conductivity, morphology (XRD, SEM) and leaching out of ionic liquid with water. FTIR studies clearly showed the interactions between SPEEK, EG and ionic liquid. The proton conductivity and dynamic mechanical properties of the composite membranes were investigated at elevated temperature and under anhydrous conditions. Proton conductivity of all the membranes measured in the temperature range of 30–140 °C under anhydrous conditions was in the range of 10 −3 Scm −1 which showed an increase with increase in temperature and amount of ionic liquid

On-demand liquid-in-liquid droplet metering and fusion utilizing pneumatically actuated membrane valves

International Nuclear Information System (INIS)

Lin, Bo-Chih; Su, Yu-Chuan

2008-01-01

This paper presents an active emulsification scheme that is capable of producing micro-droplets with desired volumes and compositions on demand. Devices with pneumatically actuated membranes constructed on top of specially designed microfluidic channels are utilized to meter and fuse liquid-in-liquid droplets. By steadily pressurizing a fluid and intermittently blocking its flow, droplets with desired volumes are dispersed into another fluid. Furthermore, droplets from multiple sources are fused together to produce combined droplets with desired compositions. In the prototype demonstration, a three-layer PDMS molding and irreversible bonding process was employed to fabricate the proposed microfluidic devices. For a dispersed-phase flow that is normally blocked by a membrane valve, the relationship between the volume (V) of a metered droplet and the corresponding valve open time (T) is found to be approximately V = kT a , in which k and a are constants determined mainly by the fluid-driving pressures. In addition to the metering device, functional droplet entrapment, fusion and flow-switching devices were also integrated in the system to produce desired combined droplets and deliver them to intended destinations upon request. As such, the demonstrated microfluidic system could potentially realize the controllability on droplet volume, composition and motion, which is desired for a variety of chemical and biological applications

Development of Nanostructured Water Treatment Membranes Based on Thermotropic Liquid Crystals: Molecular Design of Sub-Nanoporous Materials.

Science.gov (United States)

Sakamoto, Takeshi; Ogawa, Takafumi; Nada, Hiroki; Nakatsuji, Koji; Mitani, Masato; Soberats, Bartolome; Kawata, Ken; Yoshio, Masafumi; Tomioka, Hiroki; Sasaki, Takao; Kimura, Masahiro; Henmi, Masahiro; Kato, Takashi

2018-01-01

Supply of safe fresh water is currently one of the most important global issues. Membranes technologies are essential to treat water efficiently with low costs and energy consumption. Here, the development of self-organized nanostructured water treatment membranes based on ionic liquid crystals composed of ammonium, imidazolium, and pyridinium moieties is reported. Membranes with preserved 1D or 3D self-organized sub-nanopores are obtained by photopolymerization of ionic columnar or bicontinuous cubic liquid crystals. These membranes show salt rejection ability, ion selectivity, and excellent water permeability. The relationships between the structures and the transport properties of water molecules and ionic solutes in the sub-nanopores in the membranes are examined by molecular dynamics simulations. The results suggest that the volume of vacant space in the nanochannel greatly affects the water and ion permeability.

Mathematical Modeling for the Extraction of Uranium and Molybdenum with Emulsion Liquid Membrane, Including Industrial Application and Cost Evaluation of the Uranium Recovery

International Nuclear Information System (INIS)

Kris Tri Basuki

2008-01-01

Emulsion liquid membrane systems are double emulsion drops. Two immiscible phases are separated by a third phase which is immiscible with the other two phases. The liquid membrane systems were classified into two types: (1) carrier mediated mass transfer, (2) mass transfer without any reaction involved. Uranium extraction, molybdenum extraction and solvent extraction were used as purposed elements for each type of the membrane systems in the derivation of their mathematical models. Mass transfer in emulsion liquid membrane (ELM) systems has been modeled by several differential and algebraic equations. The models take into account the following : mass transfer of the solute from the bulk external phase to the external phase-membrane interface; an equilibrium reaction between the solute and the carrier to form the solute-carrier complex at the interface; mass transfer by diffusion of the solute-carrier complex in the membrane phase to the membrane-internal phase interface; another equilibrium reaction of the solute-carrier complex to release the solute at the membrane-internal phase interface into the internal phase. Models with or without the consideration of film resistances were developed and compared. The models developed in this study can predict the extraction rate through emulsion liquid membranes theoretically. All parameters required in the models can be determined before an experimental extraction run. Experimental data from literature (uranium extraction) and (molybdenum extraction and solvent extraction) were used to test the models. The agreements between the theoretical predictions and the experimental data were very good. The advantages of emulsion liquid membrane systems over traditional methods were discussed. The models developed in this research can be used directly for the design of emulsion liquid membrane systems. The results of this study represent a very significant step toward the practical applications of the emulsion liquid membrane

Chitosan/Carboxymethylcellulose/Ionic Liquid/Ag(0) Nanoparticles Form a Membrane with Antimicrobial Activity

International Nuclear Information System (INIS)

Quadros, C.; Faria, V.W.; Scheeren, C.W.; Klein, M.P.; Hertz, P.F.

2013-01-01

Silver metal nanoparticles were immobilized in chitosan/carboxymethylcellulose/BMI.BF4(1-n-butyl-3-methylimidazolium tetrafluoroborate ionic liquid) (CS/CMC/IL) to form polymeric membrane with 20 μm thickness. The CS/CMC/IL polymeric membrane was prepared using a simple solution blending method. Irregularly shaped Ag(0) nanoparticles with monomodal size distributions of nm Ag(0) were immobilized in the membrane. The presence of small Ag(0) nanoparticles induced an augmentation in the CS/CMC/IL film surface areas. The CS/CMC/IL membrane containing Ag(0) showed increase antimicrobial activity the Ag(0) concentration increased up to saturation at 10 mg. CS/CMC/IL membrane that contains Ag(0) nanoparticles has enhanced durability of the membrane and exhibited stronger antimicrobial activity against Escherichia coli and Staphylococcus aureus.

Water hyacinth cellulose-based membrane for adsorption of liquid waste dyes and chromium

Science.gov (United States)

Agtasia Putri, Cintia; Yulianti, Ian; Desianna, Ika; Sholihah, Anisa; Sujarwata

2018-04-01

Water hyacinth (Eichornia crassipes) is a weed in aquatic area whose trunk contains a lot of cellulose. Cellulose contained can be used as dyes adsorbent in a form of composite membrane. This study aims to investigate the capacity of water hyacinth cellulose-based membrane to adsorb dye and Chromium (Cr) contained in liquid. The process of membrane fabrication begins with isolation of water hyacinth cellulose. The isolated cellulose powder was used to make the membrane by mixing it with polyvinyl alcohol-polyethylene glycol (PVA-PEG) with various compositions. The morphology of membrane surface was analyzed using CCD microscope. The analysis using Ultraviolet Visible Spectroscopy (UV-Vis) and Atomic Absorption Spectroscopy (AAS) indicate that the membrane with composition ratio of cellulose: PVA: PEG of 6.5: 2.5: 1 adsorb Cr up to 38.75%.

Preparation and properties of hybrid direct methanol fuel cell membranes by embedding organophosphorylated titania submicrospheres into a chitosan polymer matrix

Energy Technology Data Exchange (ETDEWEB)

Wu, Hong [Key Laboratory for Green Chemical Technology, School of Chemical Engineering and Technology, Tianjin University, 92 Weijin Road, Nankai District, Tianjin 300072 (China); Tianjin Key Laboratory of Membrane Science and Desalination Technology, Tianjin University, Tianjin 300072 (China); Hou, Weiqiang; Wang, Jingtao; Xiao, Lulu; Jiang, Zhongyi [Key Laboratory for Green Chemical Technology, School of Chemical Engineering and Technology, Tianjin University, 92 Weijin Road, Nankai District, Tianjin 300072 (China)

2010-07-01

Organophosphorylated titania submicrospheres (OPTi) are prepared and incorporated into a chitosan (CS) matrix to fabricate hybrid membranes with enhanced methanol resistance and proton conductivity for application in direct methanol fuel cells (DMFC). The pristine monodispersed titania submicrospheres (TiO{sub 2}) of controllable particle size are synthesized through a modified sol-gel method and then phosphorylated by amino trimethylene phosphonic acid (ATMP) via chemical adsorption, which is confirmed by XPS, FTIR and TGA. The morphology and thermal property of the hybrid membranes are explored by SEM and TGA. The ionic cross-linking between the -PO{sub 3}H{sub 2} groups on OPTi and the -NH{sub 2} groups on CS lead to better compatibility between the inorganic fillers and the polymer matrix, as well as a decreased fractional free volume (FFV), which is verified by positron annihilation lifetime spectroscopy (PALS). The effects of particle size and content on the methanol permeability, proton conductivity, swelling and FFV of the membranes are investigated. Compared to pure CS membrane, the hybrid membranes exhibit an increased proton conductivity to an acceptable level of 0.01 S cm{sup -1} for DMFC application and a reduced methanol permeability of 5 x 10{sup -7} cm{sup 2} s{sup -1} at a 2 M methanol feed. (author)

Preparation and properties of hybrid direct methanol fuel cell membranes by embedding organophosphorylated titania submicrospheres into a chitosan polymer matrix

Science.gov (United States)

Wu, Hong; Hou, Weiqiang; Wang, Jingtao; Xiao, Lulu; Jiang, Zhongyi

Organophosphorylated titania submicrospheres (OPTi) are prepared and incorporated into a chitosan (CS) matrix to fabricate hybrid membranes with enhanced methanol resistance and proton conductivity for application in direct methanol fuel cells (DMFC). The pristine monodispersed titania submicrospheres (TiO 2) of controllable particle size are synthesized through a modified sol-gel method and then phosphorylated by amino trimethylene phosphonic acid (ATMP) via chemical adsorption, which is confirmed by XPS, FTIR and TGA. The morphology and thermal property of the hybrid membranes are explored by SEM and TGA. The ionic cross-linking between the -PO 3H 2 groups on OPTi and the -NH 2 groups on CS lead to better compatibility between the inorganic fillers and the polymer matrix, as well as a decreased fractional free volume (FFV), which is verified by positron annihilation lifetime spectroscopy (PALS). The effects of particle size and content on the methanol permeability, proton conductivity, swelling and FFV of the membranes are investigated. Compared to pure CS membrane, the hybrid membranes exhibit an increased proton conductivity to an acceptable level of 0.01 S cm -1 for DMFC application and a reduced methanol permeability of 5 × 10 -7 cm 2 s -1 at a 2 M methanol feed.

Enhanced Gas Separation through Nanoconfined Ionic Liquid in Laminated MoS2 Membrane.

Science.gov (United States)

Chen, Danke; Ying, Wen; Guo, Yi; Ying, Yulong; Peng, Xinsheng

2017-12-20

Two-dimensional (2D) materials-based membranes show great potential for gas separation. Herein an ionic liquid, 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF 4 ]), was confined in the 2D channels of MoS 2 -laminated membranes via an infiltration process. Compared with the corresponding bulk [BMIM][BF 4 ], nanoconfined [BMIM][BF 4 ] shows an obvious incremental increase in freezing point and a shift of vibration bands. The resulting MoS 2 -supported ionic liquid membrane (MoS 2 SILM) exhibits excellent CO 2 separation performance with high CO 2 permeance (47.88 GPU) and superb selectivity for CO 2 /N 2 (131.42), CO 2 /CH 4 (43.52), and CO 2 /H 2 (14.95), which is much better than that of neat [BMIM][BF 4 ] and [BMIM][BF 4 ]-based membranes. The outstanding performance of MoS 2 SILMs is attributed to the nanoconfined [BMIM][BF 4 ], which enables fast transport of CO 2 . Long-term operation also reveals the durability and stability of the prepared MoS 2 SILMs. The method of confining ILs in the 2D nanochannels of 2D materials may pave a new way for CO 2 capture and separation.

Ionic liquids and their hosting by polymers for HT-PEMFC membranes

Energy Technology Data Exchange (ETDEWEB)

Hana, M.; Martinez, M.; Cointeaux, L.; Lepretre, J.C. [LEPMI-ELSA, PHELMA, UMR 5631, CNRS, Grenoble INP, UJF, Saint-Martin-d' Heres (France); Molmeret, Y.; El Kissi, N. [Laboratoire de Rheologie, UMR 5520 CNRS-INPG-UJF, ENSHMG, Grenoble (France); Teles, J.; Judeinstein, P. [Institut de Chimie Moleculaire et des Materiaux d' Orsay, CNRS 8182, Orsay (France); Iojoiu, C.; Sanchez, J.Y.

2010-10-15

The paper deals with proton-conducting ionic liquids (PCILs) for use, in combination with functional polymers, in membranes operating in high temperature PEMFC. Monoammoniums derived from monoamines and half-neutralised diamines were investigated in the form of triflates. Promising results were obtained with the half-neutralised diamine-based PCIL, its conduction being governed by both Grotthuss-like and vehicular mechanisms, the respective contributions of which depend on temperature. In addition, their blending with Nafion results in a distinct reinforcement of the membrane. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

Enhanced Membrane System for Recovery of Water from Gas-Liquid Mixtures, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Gas-Liquid separation is an acute microgravity problem. Existing devices use centrifugal motion on microporous membranes to separate the two phases. Centrifugal...

THE INFLUENCE OF MIEX® RESIN FOR WATER TREATMENT EFFICIENCYIN A HYBRID MEMBRANE REACTOR

Directory of Open Access Journals (Sweden)

Mariola Rajca

2014-10-01

Full Text Available The paper presents the results of studies related to the effectiveness of removal of natural organic matter (NOM from water using hybrid membrane reactor in which ion exchange and ultrafiltration processes were performed. MIEX® resin by Orica Watercare and immersed ultrafiltration polyvinylidene fluoride capillary module ZeeWeed 1 (ZW 1 by GE Power&Water operated at negative pressure were used. The application of multifunctional reactor had a positive effect on the removal of contaminants and enabled the production of high quality water. Additionally, in refer to single stage ultrafiltration it minimalized the occurrence of membrane fouling.

Emerging trends in chemical separations with liquid membranes: an overview

International Nuclear Information System (INIS)

Shukla, J.P.

1997-01-01

It can be concluded that varied configurations of liquid membranes (LMs) will definitely play an important role in metal separations particularly in situations where other conventional chemical separation techniques fail to deliver goods. Potential areas include decontamination of biotoxic/ radioactive wastes, recovery of precious and strategic metals from lean/ extremely dilute solutions, add on to existing units, hydrometallurgy, etc

A new approach to the spectral analysis of liquid membrane oscillators by Gábor transformation

DEFF Research Database (Denmark)

Płocharska-Jankowska, E.; Szpakowska, M.; Mátéfi-Tempfli, Stefan

2006-01-01

Liquid membrane oscillators very frequently have an irregular oscillatory behavior. Fourier transformation cannot be used for these nonstationary oscillations to establish their power spectra. This important point seems to be overlooked in the field of chemical oscillators. A new approach...... is presented here based on Gábor transformation allowing one to obtain power spectra of any kind of oscillations that can be met experimentally. The proposed Gábor analysis is applied to a liquid membrane oscillator containing a cationic surfactant. It was found that the power spectra are strongly influenced...

Double liquid membrane system for the removal of actinides and lanthanides from acidic nuclear wastes

International Nuclear Information System (INIS)

Chiarizia, R.; Danesi, P.R.

1985-01-01

Supported liquid membranes (SLM), consisting of an organic solution of n-octyl-(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) and tributyl-phosphate (TBP) in decalin are able to perform selective separation and concentration of actinide and lanthanide ions from aqueous nitrate feed solutions and synthetic nuclear wastes. In the membrane process a possible strip solution is a mixture of formic acid and hydroxylammonium formate (HAF). The effectiveness of this strip solution is reduced and eventually nullified by the simultaneous transfer through the SLM of nitric acid which accumulates in the strip solution. A possible way to overcome this drawback is to make use of a second SLM consisting of a primary amine which is able to extract only HNO 3 from the strip solution. In this work the results obtained by experimentally studying the membrane system: synthetic nuclear waste/CMPO-TBP membrane/HCOOH-HAF strip solution/primary amine membrane/NaOH solution, are reported. They show that the use of a second liquid membrane is effective in controlling the HNO 3 concentration in the strip solution, thus allowing the actinide and lanthanide ions removal from the feed solution to proceed to completion. 15 refs., 10 figs., 1 tab

Solar assisted liquid desiccant cooling using clay based membranes

Directory of Open Access Journals (Sweden)

Priya S. Shanmuga

2018-01-01

Full Text Available The environmental concerns have led to the urge of the usage of non-conventional energy resources like solar, wind, thermal, geothermal etc. which provide enormous source of energy without causing any further diminution of the environment. Instead of the conventional HVAC systems that cause colossal environmental perils, usage of liquid desiccants in coming in vogue whereby reducing ecological threats. Moreover, solar assisted systems provide further impulse to such systems. This paper discusses about the various comparisons between liquid desiccants: Lithium chloride, Potassium formate and Calcium chloride and concludes that potassium formate is the best desiccant to be used among the three. Potassium formate (HCOOK is used which is cheaper and less corrosive as compared to the other aqueous salts, and has a negative crystallization temperature. Potassium formate is a new liquid desiccant and thus, not much research is available currently. The weather conditions of Manipal provide an appropriate condition for the experimentations of solar aided liquid desiccant evaporative cooling systems due to its humid climate and intense solar radiation obtained. The small scale experimentation also encounters the problem of liquid desiccant carryover by the air flow, with the help of clay based membranes which are again cheap, environmentally benign and obtained in a facile way. The projected system takes complete advantage of pure solar energy aimed at the regeneration of liquid desiccant.

Sympathetic cooling of a membrane oscillator in a hybrid mechanical-atomic system

Science.gov (United States)

Jöckel, Andreas; Faber, Aline; Kampschulte, Tobias; Korppi, Maria; Rakher, Matthew T.; Treutlein, Philipp

2015-01-01

Sympathetic cooling with ultracold atoms and atomic ions enables ultralow temperatures in systems where direct laser or evaporative cooling is not possible. It has so far been limited to the cooling of other microscopic particles, with masses up to 90 times larger than that of the coolant atom. Here, we use ultracold atoms to sympathetically cool the vibrations of a Si3N4 nanomembrane, the mass of which exceeds that of the atomic ensemble by a factor of 1010. The coupling of atomic and membrane vibrations is mediated by laser light over a macroscopic distance and is enhanced by placing the membrane in an optical cavity. We observe cooling of the membrane vibrations from room temperature to 650 ± 230 mK, exploiting the large atom-membrane cooperativity of our hybrid optomechanical system. With technical improvements, our scheme could provide ground-state cooling and quantum control of low-frequency oscillators such as nanomembranes or levitated nanoparticles, in a regime where purely optomechanical techniques cannot reach the ground state.

Renewable energy powered membrane technology. 2. The effect of energy fluctuations on performance of a photovoltaic hybrid membrane system.

Science.gov (United States)

Richards, B S; Capão, D P S; Schäfer, A I

2008-06-15

This paper reports on the performance fluctuations during the operation of a batteryless hybrid ultrafiltration--nanofiltration/reverse osmosis (UF-NF/RO) membrane desalination system powered by photovoltaics treating brackish groundwater in outback Australia. The renewable energy powered membrane (RE-membrane) system is designed to supply clean drinking water to a remote community of about 50 inhabitants. The performance of the RE-membrane system over four different solar days is summarized using four different NF membranes (BW30, NF90, ESPA4, TFC-S), and examined in more detail for the BW30 membrane. On an Australian spring day, the system produced 1.1 m3 of permeate with an average conductivity of 0.28 mS x cm(-1), recovering 28% of the brackish (8.29 mS x cm(-1) conductivity) feedwater with an average specific energy consumption of 2.3 kWh x m(-3). The RE-membrane system tolerated large fluctuations in solar irradiance (500--1200 W x m(-2)), resulting in only small increases in the permeate conductivity. When equipped with the NF90 (cloudy day) and ESPA4 (rainy day) membranes, the system was still able to produce 1.36 m(-3) and 0.85 m(-3) of good quality permeate, respectively. The TFC-S membrane was not able to produce adequate water quality from the bore water tested. It is concluded that batteryless operation is a simple and robust way to operate such systems under conditions ranging from clear skies to medium cloud cover.

Ionic Liquid-Nanoparticle Hybrid Electrolytes and their Application in Secondary Lithium-Metal Batteries

KAUST Repository

Lu, Yingying

2012-07-12

Ionic liquid-tethered nanoparticle hybrid electrolytes comprised of silica nanoparticles densely grafted with imidazolium-based ionic liquid chains are shown to retard lithium dendrite growth in rechargeable batteries with metallic lithium anodes. The electrolytes are demonstrated in full cell studies using both high-energy Li/MoS2 and high-power Li/TiO2 secondary batteries. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Treatment of Medical Radioactive Liquid Waste Using Forward Osmosis (FO) Membrane Process

KAUST Repository

Lee, Songbok

2018-04-07

The use of forward osmosis (FO) for concentrating radioactive liquid waste from radiation therapy rooms in hospitals was systematically investigated in this study. The removal of natural and radioactive iodine using FO was first investigated with varying pHs and draw solutions (DSs) to identify the optimal conditions for FO concentration. Results showed that FO had a successful rejection rate for both natural and radioactive iodine (125I) of up to 99.3%. This high rejection rate was achieved at a high pH, mainly due to electric repulsion between iodine and membrane. Higher iodine removal by FO was also attained with a DS that exhibits a reverse salt flux (RSF) adequate to hinder iodine transport. Following this, actual radioactive medical liquid waste was collected and concentrated using FO under these optimal conditions. The radionuclides in the medical waste (131I) were removed effectively, but the water recovery rate was limited due to severe membrane fouling. To enhance the recovery rate, hydraulic washing was applied, but this had only limited success due to combined organic-inorganic fouling of the FO membrane. Finally, the effect of FO concentration on the reduction of septic tank volume was simulated as a function of recovery rate. To our knowledge, this study is the first attempt to explore the potential of FO technology for treating radioactive waste, and thus could be expanded to the dewatering of the radioactive liquid wastes from a variety of sources, such as nuclear power plants.

Removal of some ions from the radioactive liquid wastes by means of membrane techniques

International Nuclear Information System (INIS)

Roman, Gabriela; Garganciuc, Dana; Batrinescu, Gheorghe; Popescu, Georgeta

2000-01-01

The radioactive wastes imply important problems in the pollution control. Contrary to the case of other liquid wastes, which are specifically treated depending on the nature of pollutants, the liquid radioactive wastes are treated as a function of their activity (high, medium or low) and not depending on the nature of radioisotopes. The paper presents the advantages of the membrane processes as comparing with the classical processes in the removal of some ions from liquid radioactive waste up to values admissible of the current standards. Two types of radioactive liquid solutions were processed namely: one solution from the decontamination of the parts of an installation and other from the decontamination of primary circuit of the nuclear power plant. The first solution was treated with ultrafiltration and reverse osmosis, the retention for radioactive and toxic elements ranging between 14 - 69% for ultrafiltration and 63 - 99% for reverse osmosis. The second solution was processed only with reverse osmosis, a retention between 64 - 98% being obtained. The tests proved that by reverse osmosis membrane process a good removal efficiency of radioactive elements from liquid waste is obtained, corresponding to the requirements imposed by the current regulations. (author)

Transport of strontium and some 1. and 2. group's cations through hollow fiber supported liquid membranes using crowns

International Nuclear Information System (INIS)

Mackova, J.

1996-01-01

Models which describe the permeation of strontium cation through liquid membranes are shown in this paper. Partition coefficients have been determined radiometrically, using Sr-85 tracer. The results were treated according to the theory developed by Danesi using simple equation. The permeation of Sr 2+ using 18-crown-6 crown ether (18C6) and picric acid in bulk liquid toluene membrane systems with and without surface/active substances (SPAN 80, ECA 4360) has been studied. The transport of Sr 2+ using 18-C-6 ether as a carrier and picrate as a co-counter ion through hollow fiber supported dichlorobenzene liquid membrane has been studied too. A polypropylene hollow fiber ACCUREL PP type S6/ENKA and a permeation device with a single hollow fiber module with on-line radiometric detection of strontium using Sr-85 tracer, was used. This type of permeation system has shown reproducible results, fast and effective permeation. Results prove the possible mechanism of strontium cation transport though liquid membrane. Another subject of study was the transport of metal ions (Ca 2+ , Sr 2+ , Ba 2+ , Na + , K + , Cs + ) using (18C6) as a carrier and picrate as co/counter ion through hollow fiber supported dichlorobenzene liquid membrane using capillary isotachophoresis (ITP) measurement of the cations concentration. The experimental results obtained using ITP method for Sr 2+ concentration determination are in good agreement with those obtained by on-line radiometric detection using Sr-85 tracer, under the same conditions (feed, membrane, strip, hollow fiber and the same pertraction device). The ITP method could be successfully used for analyses of samples containing a mixture of all separated cations. The results of this study indicate that the polypropylene hollow fiber supported dichlorobenzene membrane is suitable for studied metal cation transport using 18C6 as a carrier and a picrate as co-counter ion. This combination enables fast and effective cation separation. The

Triple-bore hollow fiber membrane contactor for liquid desiccant based air dehumidification

KAUST Repository

Bettahalli Narasimha, Murthy Srivatsa; Lefers, Ryan; Fedoroff, Nina V.; Leiknes, TorOve; Nunes, Suzana Pereira

2016-01-01

the potential for desiccant carryover to the air and the potential for contamination of the liquid desiccant by dust and other airborne materials, as well as minimizing corrosion. However, the expected additional mass transport barrier of the membrane surface

Nuclear liquid wastes treatment: study of the reverse osmosis membranes degradation under γ irradiation

International Nuclear Information System (INIS)

Combernoux, Nicolas

2015-01-01

The treatment of nuclear liquid wastes by reverse osmosis (RO) involved issues of the water radiolysis and the membrane ageing due to γ irradiation effects. Membrane performances (permeability, strontium and cesium retention) were assessed after γ irradiation. Irradiation was carried out with an external 60 Co source in different conditions that simulated real used of the process (dose from 0.1 to 1 MGy, dose rate of 0.5 and 5 kGy.h -1 , with or without oxygen or water). Several analytical methods were performed to evaluate irradiation effects (ATR-FTIR, XPS, gas production, water soluble species released from the membrane). The methodology developed led to relevant information due to an innovative analytical protocol. Membrane performances started dropping between 0.2 and 0.5 MGy with oxygen and water (dose rate 0.5 kGy.h -1 ). This shift was linked to chains scissions inside the membrane active layer. The membrane degradation was weaker without oxygen or water or at high dose rate (5 kGy.h -1 ). Results showed that each analysis comforted each other. Membrane performances were also evaluated with three different types of liquid effluents, representing radioactive effluents from a post-disaster situation (groundwater type), disaster situation (seawater) or process water. Experiments were carried out at lab and pilot scales. Results indicated that the treatment of each effluent was possible by RO with an adequate choice of membrane and operating parameters. Finally, the time to reach an integrated dose threshold for the membrane in real conditions was estimated with the RABBI software: a dozen of days in the case of disaster situation to several years in the two other cases. (author) [fr

Poly (ether imide sulfone) membranes from solutions in ionic liquids

KAUST Repository

Kim, Dooli

2017-11-20

A membrane manufacture method based on non-volatile solvents and a high performance polymer, poly (ether imide sulfone) (EXTEM™), is proposed, as greener alternative to currently industrial process. We dissolved EXTEM™ in pure ionic liquids: 1-ethyl-3-methylimidalzolium thiocyanate ([EMIM]SCN), 1-butyl-3-methylimidalzolium thiocyanate ([BMIM]SCN), and 1-ethyl-3-methylimidalzolium acetate ([EMIM]OAc). The following polymer solution parameters were evaluated to optimize the manufacture: Gibbs free energy of mixing (G), intrinsic viscosity ([]) and hydrodynamic diameter. Membranes with sponge-like structure and narrow pore size distribution were obtained from solutions in [EMIM]SCN. They were tested for separation of proteins and deoxyribonucleic acids (DNA). Due to the polymer stability, we foresee that applications in more demanding chemical separations would be possible. [EMIM]SCN was 96 % purified and recovered after the membrane fabrication, contributing to the sustainability of the whole manufacturing process.

Effect of dope solution temperature on the membrane structure and membrane distillation performance

Science.gov (United States)

Nawi, N. I. M.; Bilad, M. R.; Nordin, N. A. H. M.

2018-04-01

Membrane distillation (MD) is a non-isothermal process applicable to purify water using hydrophobic membrane. Membrane in MD is hydrophobic, permeable to water vapor but repels liquid water. MD membrane is expected to pose high flux, high fouling and scaling resistances and most importantly high wetting resistance. This study develops flat-sheet polyvinylidene fluoride (PVDF) membrane by exploring both liquid-liquid and liquid-solid phase inversion technique largely to improve its wetting resistance and flux performance. We hypothesize that temperature of dope solution play roles in solid-liquid separation during membrane formation and an optimum balance between liquid-liquid and liquid-solid (crystallization) separation leads to highly performance PVDF membrane. Findings obtained from differential scanning calorimeter test show that increasing dope solution temperature reduces degree of PVDF crystallinity and suppresses formation of crystalline structure. The morphological images of the resulting membranes show that at elevated dope solution temperature (40, 60, 80 and 100°C), the spherulite-like structures are formed across the thickness of membranes ascribed from due to different type of crystals. The performance of direct-contact MD shows that the obtained flux of the optimum dope temperature (60°C) of 10.8 L/m2h is comparable to commercial PTFE-based MD membrane.

Transport Asymmetry of Novel Bi-Layer Hybrid Perfluorinated Membranes on the Base of MF-4SC Modified by Halloysite Nanotubes with Platinum

Directory of Open Access Journals (Sweden)

Anatoly Filippov

2018-03-01

Full Text Available Three types of bi-layer hybrid nanocomposites on the base of perfluorinated cation-exchange membrane MF-4SC (Russian analogue of Nafion®-117 were synthesized and characterized. It was found that two membranes possess the noticeable asymmetry of the current–voltage curve (CVC under changing their orientation towards the applied electric field, despite the absence of asymmetry of diffusion permeability. These phenomena were explained in the frame of the “fine-porous model” expanded for bi-layer membranes. A special procedure to calculate the real values of the diffusion layers thickness and the limiting current density was proposed. Due to asymmetry effects of the current voltage curves of bi-layer hybrid membranes on the base of MF-4SC, halloysite nanotubes and platinum nanoparticles, it is prospective to assemble membrane switches (membrane relays or diodes with predictable transport properties, founded upon the theory developed here.

Possible applications of crown-ethers to metal extraction using liquid membrane technology - a literature survey

International Nuclear Information System (INIS)

Dozol, M.

1990-01-01

Ether-crowns, discovered in 1967 by J.C. PEDERSEN, exhibit attractive complexive and extractive properties, enhanced in various fields, such as analytical chemistry, chemical synthesis, field of biology, or extractive chemistry. The investigations carried out on these macrocyclic compounds are continually increasing, as show in international literature. Among the focus of interest, the applications to metal extraction are extensively studied with crown compounds present in liquid phase or impregnated on supports (membranes or resins). The goal of this paper is to describe the application of crown-ethers to metal extraction, using liquid membrane processes. 69 refs

Hybrid Pressure Retarded Osmosis−Membrane Distillation (PRO−MD) Process for Osmotic Power and Clean Water Generation

KAUST Repository

Han, Gang; Zuo, Jian; Wan, Chunfeng; Chung, Neal Tai-Shung

2015-01-01

unique advantages of high water recovery rate, huge osmotic power generation, well controlled membrane fouling, and minimal environmental impacts. Experimental results show that the PRO−MD hybrid process is promising that not only can harvest osmotic

Poly(ionic liquid)/Ionic Liquid Ion-Gels with High "Free" Ionic Liquid Content: Platform Membrane Materials for CO2/Light Gas Separations.

Science.gov (United States)

Cowan, Matthew G; Gin, Douglas L; Noble, Richard D

2016-04-19

-films (ca. 100-nm-thick active layer). Traditional polymeric membrane materials are limited by a trade-off between permeability and selectivity empirically described by the "Robeson upper bound"-placing the desired membrane properties beyond reach. Therefore, the investigation of advanced and composite materials that can overcome the limitations of traditional polymeric materials is the focus of significant academic and industrial research. In particular, there has been substantial work on ionic-liquid (IL)-based materials due to their gas transport properties. This review provides an overview of our collaborative work on developing poly(ionic liquid)/ionic liquid (PIL/IL) ion-gel membrane technology. We detail developmental work on the preparation of PIL/IL composites and describe how this chemical technology was adapted to allow the roll-to-roll processing and preparation of membranes with defect-free active layers ca. 100 nm thick, CO2 permeances of over 6000 GPU, and CO2/N2 selectivity of ≥20-properties with the potential to reduce the cost of CO2 removal from coal-fired power plant flue gas to ca. $15 per ton of CO2 captured. Additionally, we examine the materials developments that have produced advanced PIL/IL composite membranes. These advancements include cross-linked PIL/IL blends, step-growth PIL/IL networks with facilitated transport groups, and PIL/IL composites with microporous additives for CO2/CH4 separations.

The effect of peptides and ions interacting with an electrically neutral membrane interface on the structure and stability of lipid membranes in the liquid-crystalline phase and in the liquid-ordered phase

Science.gov (United States)

Sano, Ryoko; Masum, Shah Md; Tanaka, Tomoki; Yamashita, Yuko; Levadny, Victor; Yamazaki, Masahito

2005-08-01

We investigated the effects of a de novo designed peptide, WLFLLKKK (peptide-1) and La3+, which can bind with the electrically neutral lipid membrane interface, on the stability of the phosphatidylcholine (PC) membrane in the Lα phase and that of the liquid-ordered (lo) phase membranes. The results of spacing of the multilamellar vesicle and shape changes of the giant unilamellar vesicle (GUV) indicate that the peptide-1 can be partitioned into the membrane interface in the Lα phase but not into that in the lo phase. La3+ induced shape changes of GUVs of the lo phase membrane, which are the same as those of GUVs in the Lα phase. This indicates that the binding of La3+ induced an increase in the lateral compression pressure of the membrane, which decreased the surface area of the membrane in the lo phase. The difference of the membrane interface between the Lα phase and the lo phase is discussed.

The effect of peptides and ions interacting with an electrically neutral membrane interface on the structure and stability of lipid membranes in the liquid-crystalline phase and in the liquid-ordered phase

International Nuclear Information System (INIS)

Sano, Ryoko; Masum, Shah Md; Tanaka, Tomoki; Yamashita, Yuko; Levadny, Victor; Yamazaki, Masahito

2005-01-01

We investigated the effects of a de novo designed peptide, WLFLLKKK (peptide-1) and La 3+ , which can bind with the electrically neutral lipid membrane interface, on the stability of the phosphatidylcholine (PC) membrane in the L α phase and that of the liquid-ordered (lo) phase membranes. The results of spacing of the multilamellar vesicle and shape changes of the giant unilamellar vesicle (GUV) indicate that the peptide-1 can be partitioned into the membrane interface in the L α phase but not into that in the lo phase. La 3+ induced shape changes of GUVs of the lo phase membrane, which are the same as those of GUVs in the L α phase. This indicates that the binding of La 3+ induced an increase in the lateral compression pressure of the membrane, which decreased the surface area of the membrane in the lo phase. The difference of the membrane interface between the L α phase and the lo phase is discussed

Experimental study of a hybrid electro-acoustic nonlinear membrane absorber

Science.gov (United States)

Bryk, P. Y.; Bellizzi, S.; Côte, R.

2018-06-01

A hybrid electro-acoustic nonlinear membrane absorber working as a nonlinear energy sink (here after named EA-NES) is described. The device is composed of a thin circular visco-elastic membrane working as an essentially cubic oscillator. One face of the membrane is coupled to the acoustic field to be reduced and the other face is enclosed. The enclosure includes a loudspeaker for the control of the acoustic pressure felt by the rear face of the membrane through proportional feedback control. An experimental set-up has been developed where the EA-NES is weakly coupled to a linear acoustic system. The linear acoustic system is an open-ended tube, coupled on one side to the EA-NES by a box, and on the other side to a source loudspeaker by another box. Only sinusoidal forcing is considered. It is shown that the EA-NES is able to perform resonance capture with the acoustic field, resulting in noise reduction by targeted energy transfer, and to operate in a large frequency band, tuning itself passively to any linear system. We demonstrate the ability of the feedback gain defining the active loop to modify the resonance frequency of the EA-NES, which is a key factor to tune the triggering threshold of energy pumping. The novelty of this work is to use active control combined to passive nonlinear transfer energy to improve it. In this paper, only experimental results are analyzed.

Recovery of salicylic acid from aqueous solution by solvent extraction and supported liquid membrane using TOMAC as carrier

International Nuclear Information System (INIS)

Kouki, Noura; Tayeb, Rafik; Dhahbi, Mahmoud

2009-01-01

Conventional sewage treatment plants do not fully degrade residues of pharmaceuticals, so that they are introduced into the aquatic environment. On this basis, the demand for the development of efficient systems for removing these compounds from water has assumed a great research interest. Membrane operations are increasingly employed in many industrial sectors as important alternative technologies to the classical processes of separation. Among membrane-based separation processes, the use of supported liquid membranes (SLMs) has received growing attention during recent years. In our work we had tried to recover a pharmaceutical product, salicylic acid (S.A), from an aqueous solution by solvent extraction and supported liquid membrane using an ionic liquid: the tri octylmethylammonium chloride (TOMAC) as carrier. Ionic liquids has been revealed as interesting clean alternatives to classical solvents and their use as a liquid phase results in the stabilization of the SLMs duo to their negligible vapour pressure, the possibility of minimising their solubility in the surrounding phases by adequate selection of the cation and anion, and the greater capillary force associated with their high viscosity. For this reason we had studied the influence of different parameters which could affect the efficiency of the transport: pH of the feed phase, the nature of the strippant, the concentration of the strippant, the nature of the support and the initial concentration of the salicylic acid in the feed phase. We had noticed that the pH of the feed solution had no effect of the percentage extraction and after 24 hours we can extract completely our solute. TOMAC seemed to be a good extractant but we found difficult to strip salicylic acid from the TOMAC phase and this could be related to the formation of water micro environments in the ionic liquid membrane.

Pervaporation and sorption behavior of zeolite-filled polyethylene glycol hybrid membranes for the removal of thiophene species.

Science.gov (United States)

Lin, Ligang; Zhang, Yuzhong; Li, Hong

2010-10-01

Polyethylene glycol (PEG)-CuY zeolite hybrid membranes were prepared for sulfur removal from gasoline feed. The sorption and diffusion behavior of typical gasoline components through the hybrid membranes has been investigated by systematic studies of dynamic sorption curves. Influencing factors including feed temperature, permeate pressure, and zeolite content in the membranes on membrane performance have been evaluated. Immersion experiments results showed the preferential sorption of thiophene, which is key in fulfilling the separation of thiophene/hydrocarbon mixtures. The sorption, diffusion, and permeation coefficients of gasoline components in filled membranes are higher than those in unfilled membranes. Pervaporation (PV) and gas chromatography (GC) experiments results corresponded to the discussions on dynamic sorption curves. PV experiments showed that lower permeate pressure meant higher separation performance. The optimum temperature occurred at 383K, and an Arrhenius relationship existed between permeation flux and operating temperature. The CuY zeolite filling led to a significant increase of flux since the porous zeolite provides for more diffusion for small molecules in mixed matrix membranes. The sulfur enrichment factor increased first and then decreased with the increasing zeolite content, which was attributed to the combined influence of complexation force between CuY and thiophenes as well as the trade-off phenomenon between flux and selectivity. At 9 wt% CuY content, a higher permeation flux (3.19 kg/(m(2) h)) and sulfur enrichment factor (2.95) were obtained with 1190 microg/g sulfur content level in gasoline feed. Copyright 2010 Elsevier Inc. All rights reserved.

Ionic liquids in proton exchange membrane fuel cells: Efficient systems for energy generation

Energy Technology Data Exchange (ETDEWEB)

Padilha, Janine C.; Basso, Juliana; da Trindade, Leticia G.; Martini, Emilse M.A.; de Souza, Michele O.; de Souza, Roberto F. [Institute of Chemistry, UFRGS, Av. Bento Goncalves 9500, Porto Alegre 91501-970, P.O. Box 15003 (Brazil)

2010-10-01

Proton exchange membrane fuel cells (PEMFCs) are used in portable devices to generate electrical energy; however, the efficiency of the PEMFC is currently only 40%. This study demonstrates that the efficiency of a PEMFC can be increased to 61% when 1-butyl-3-methylimidazolium tetrafluoroborate (BMI.BF{sub 4}) ionic liquid (IL) is used together with the membrane electrode assembly (MEA). The results for ionic liquids (ILs) 1-butyl-3-methylimidazolium chloride (BMI.Cl) and 1-butyl-3-methylimidazolium tetrafluoroborate (BMI.BF{sub 4}) in aqueous solutions are better than those obtained with pure water. The current and the power densities with IL are at least 50 times higher than those obtained for the PEMFC wetted with pure water. This increase in PEMFC performance can greatly facilitate the use of renewable energy sources. (author)

Basic technology for {sup 6}Li enrichment using an ionic-liquid impregnated organic membrane

Energy Technology Data Exchange (ETDEWEB)

Hoshino, Tsuyoshi, E-mail: hoshino.tsuyoshi@jaea.go.jp [Blanket Irradiation and Analysis Group, Fusion Research and Development Directorate, Japan Atomic Energy Agency, 4002, Narita-cho, Oarai-machi, Higashi Ibaraki-gun, Ibaraki 311-1393 (Japan); Terai, Takayuki [The Institute of Engineering Innovation and Department of Nuclear Engineering and Management School of Engineering, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-8656 (Japan)

2011-10-01

The tritium needed as a fuel for fusion reactors is produced by the neutron capture reaction of lithium-6 ({sup 6}Li) in tritium breeding materials. However, natural Li contains only about 7.6 at.% {sup 6}Li. In this paper, a new lithium isotope separation technique using an ionic-liquid impregnated organic membrane is proposed. In order to separate and concentrate lithium isotopes, only lithium ions are able to move through the membrane by electrodialysis between the cathode and the anode in lithium solutions. Preliminary experiments of lithium isotope separation were conducted using this phenomenon. Organic membranes impregnated with TMPA-TFSI and PP13-TFSI as ionic liquids were prepared, and the relationship between the {sup 6}Li separation coefficient and the applied electrodialytic conditions was evaluated using them. The results showed that the {sup 6}Li isotope separation coefficient in this method (about 1.1-1.4) was larger than that in the mercury amalgam method (about 1.06).

A hybrid microbial fuel cell membrane bioreactor with a conductive ultrafiltration membrane biocathode for wastewater treatment

KAUST Repository

Malaeb, Lilian; Katuri, Krishna; Logan, Bruce E.; Maab, Husnul; Nunes, Suzana Pereira; Saikaly, Pascal

2013-01-01

A new hybrid, air-biocathode microbial fuel cell-membrane bioreactor (MFC-MBR) system was developed to achieve simultaneous wastewater treatment and ultrafiltration to produce water for direct reclamation. The combined advantages of this system were achieved by using an electrically conductive ultrafiltration membrane as both the cathode and the membrane for wastewater filtration. The MFC-MBR used an air-biocathode, and it was shown to have good performance relative to an otherwise identical cathode containing a platinum catalyst. With 0.1 mm prefiltered domestic wastewater as the feed, the maximum power density was 0.38 W/m2 (6.8 W/m3) with the biocathode, compared to 0.82 W/m2 (14.5 W/m3) using the platinum cathode. The permeate quality from the biocathode reactor was comparable to that of a conventional MBR, with removals of 97% of the soluble chemical oxygen demand, 97% NH3-N, and 91% of total bacteria (based on flow cytometry). The permeate turbidity was <0.1 nephelometric turbidity units. These results show that a biocathode MFC-MBR system can achieve high levels of wastewater treatment with a low energy input due to the lack of a need for wastewater aeration. © 2013 American Chemical Society.

A hybrid microbial fuel cell membrane bioreactor with a conductive ultrafiltration membrane biocathode for wastewater treatment

KAUST Repository

Malaeb, Lilian

2013-10-15

A new hybrid, air-biocathode microbial fuel cell-membrane bioreactor (MFC-MBR) system was developed to achieve simultaneous wastewater treatment and ultrafiltration to produce water for direct reclamation. The combined advantages of this system were achieved by using an electrically conductive ultrafiltration membrane as both the cathode and the membrane for wastewater filtration. The MFC-MBR used an air-biocathode, and it was shown to have good performance relative to an otherwise identical cathode containing a platinum catalyst. With 0.1 mm prefiltered domestic wastewater as the feed, the maximum power density was 0.38 W/m2 (6.8 W/m3) with the biocathode, compared to 0.82 W/m2 (14.5 W/m3) using the platinum cathode. The permeate quality from the biocathode reactor was comparable to that of a conventional MBR, with removals of 97% of the soluble chemical oxygen demand, 97% NH3-N, and 91% of total bacteria (based on flow cytometry). The permeate turbidity was <0.1 nephelometric turbidity units. These results show that a biocathode MFC-MBR system can achieve high levels of wastewater treatment with a low energy input due to the lack of a need for wastewater aeration. © 2013 American Chemical Society.

Industrial applications of membrane processes in chemistry and energy generation; Applications industrielles des procedes membranaires en chimie et production d'energie

Energy Technology Data Exchange (ETDEWEB)

NONE

2005-07-01

The French membranes club (CFM), with the sustain of the French institute of petroleum (IFP) has organized this meeting which aims to present the most recent industrial realizations in the domain of membrane processes in the chemistry and energy generation sectors. This document gathers the abstracts of the presentations: 1 - hydrogen purification and CO{sub 2} extraction: development of polymer matrix and metal nano-particulate hybrid membranes for selective membrane applications; study of silicone-based mixed matrix membranes for hydrogen purification via inverse selectivity principle; CO{sub 2} capture from gaseous effluents for its sequestration: role and limitations of membrane processes; membranes and processes for the abatement of the acid gas content of smokes; new structural model for Nafion{sup R} membranes, the benchmark polymer for low temperature fuel cells; 2 - molecular screen-based membranes: MFI-alumina nano-composite ceramic membranes: preparation and characterization, gaseous transport and separation; characterization and permeation properties of supported MFI membranes; in-situ measurement of butane isomers diffusion in MFI zeolite membranes through transient permeation tests; 3 - vapors separation: stability of silver particulates in PA12-PTMO/AgBF{sub 4} composite membranes and its effect on the easier ethylene transport inside these membranes; 4 - separation of liquid organic mixtures: isomers separation using cyclo-dextrins bearing membranes: application to the extraction and separation of xylene isomers; electrodialysis in organic environment: application to the electro-synthesis; study of polymer materials permeability; 5 - treatment of industrial waters: use of NanoFlux software in the modeling of nano-filtration membrane processes in the chemical industry: elimination of sulfate impurities from 'Chloralkali' brines; ultra-filtration of a wastewater containing partially emulsified oil; efficiency of a hybrid membrane separation

Highly Selective Separation of Carbon Dioxide from Nitrogen and Methane by Nitrile/Glycol-Difunctionalized Ionic Liquids in Supported Ionic Liquid Membranes (SILMs)

OpenAIRE

Hojniak, Sandra D.; Silverwood, Ian P.; Laeeq Khan, Asim; Vankelecom, Ivo F.J.; Dehaen, Wim; Kazarian, Sergei G.; Binnemans, Koen

2014-01-01

Novel difunctionalized ionic liquids (ILs) containing a triethylene glycol monomethyl ether chain and a nitrile group on a pyrrolidinium or imidazolium cation have been synthesized and incorporated into supported ionic liquid membranes (SILMs). These ILs exhibit ca. 2.3 times higher CO2/N2 and CO2/CH4 gas separation selectivities than analogous ILs functionalized only with a glycol chain. Although the glycol moiety ensures room temperature liquidity of the pyrrolidinium and imidazolium ILs, t...

Removal of trace organic chemicals and performance of a novel hybrid ultrafiltration-osmotic membrane bioreactor.

Science.gov (United States)

Holloway, Ryan W; Regnery, Julia; Nghiem, Long D; Cath, Tzahi Y

2014-09-16

A hybrid ultrafiltration-osmotic membrane bioreactor (UFO-MBR) was investigated for over 35 days for nutrient and trace organic chemical (TOrC) removal from municipal wastewater. The UFO-MBR system uses both ultrafiltration (UF) and forward osmosis (FO) membranes in parallel to simultaneously extract clean water from an activated sludge reactor for nonpotable (or environmental discharge) and potable reuse, respectively. In the FO stream, water is drawn by osmosis from activated sludge through an FO membrane into a draw solution (DS), which becomes diluted during the process. A reverse osmosis (RO) system is then used to reconcentrate the diluted DS and produce clean water suitable for direct potable reuse. The UF membrane extracts water, dissolved salts, and some nutrients from the system to prevent their accumulation in the activated sludge of the osmotic MBR. The UF permeate can be used for nonpotable reuse purposes (e.g., irrigation and toilet flushing). Results from UFO-MBR investigation illustrated that the chemical oxygen demand, total nitrogen, and total phosphorus removals were greater than 99%, 82%, and 99%, respectively. Twenty TOrCs were detected in the municipal wastewater that was used as feed to the UFO-MBR system. Among these 20 TOrCs, 15 were removed by the hybrid UFO-MBR system to below the detection limit. High FO membrane rejection was observed for all ionic and nonionic hydrophilic TOrCs and lower rejection was observed for nonionic hydrophobic TOrCs. With the exceptions of bisphenol A and DEET, all TOrCs that were detected in the DS were well rejected by the RO membrane. Overall, the UFO-MBR can operate sustainably and has the potential to be utilized for direct potable reuse applications.

Transfer of heparin polyion across a polarized water/ionic liquid membrane interface

Czech Academy of Sciences Publication Activity Database

Langmaier, Jan; Samec, Zdeněk; Samcová, E.; Tůma, P.

2012-01-01

Roč. 24, OCT 2012 (2012), s. 25-27 ISSN 1388-2481 R&D Projects: GA ČR GAP206/11/0707 Institutional support: RVO:61388955 Keywords : heparin polyion * ionic liquid membrane * amperometric detection Subject RIV: CG - Electrochemistry Impact factor: 4.425, year: 2012

Copper recovery in a bench-scale carrier facilitated tubular supported liquid membrane system

Directory of Open Access Journals (Sweden)

Makaka S.

2010-01-01

Full Text Available The extraction of copper ions in a tubular supported liquid membrane using LIX 984NC as a mobile carrier was studied, evaluating the effect of the feed characteristics (flowrate, density, viscosity on the feedside laminar layer of the membrane. A vertical countercurrent, double pipe perspex benchscale reactor consisting of a single hydrophobic PVDF tubular membrane mounted inside was used in all test work. The membrane was impregnated with LIX 984NC and became the support for this organic transport medium. Dilute Copper solution passed through the centre pipe and sulphuric acid as strippant passed through the shell side. Copper was successfully transported from the feedside to the stripside and from the data obtained, a relationship between Schmidt, Reynolds and Sherwood number was achieved of.

Giant plasma membrane vesicles: models for understanding membrane organization.

Science.gov (United States)

Levental, Kandice R; Levental, Ilya

2015-01-01

The organization of eukaryotic membranes into functional domains continues to fascinate and puzzle cell biologists and biophysicists. The lipid raft hypothesis proposes that collective lipid interactions compartmentalize the membrane into coexisting liquid domains that are central to membrane physiology. This hypothesis has proven controversial because such structures cannot be directly visualized in live cells by light microscopy. The recent observations of liquid-liquid phase separation in biological membranes are an important validation of the raft hypothesis and enable application of the experimental toolbox of membrane physics to a biologically complex phase-separated membrane. This review addresses the role of giant plasma membrane vesicles (GPMVs) in refining the raft hypothesis and expands on the application of GPMVs as an experimental model to answer some of key outstanding problems in membrane biology. Copyright © 2015 Elsevier Inc. All rights reserved.

Hybrid Pressure Retarded Osmosis−Membrane Distillation (PRO−MD) Process for Osmotic Power and Clean Water Generation

KAUST Repository

Han, Gang

2015-05-20

A novel pressure retarded osmosis−membrane distillation (PRO−MD) hybrid process has been experimentally conceived for sustainable production of renewable osmotic power and clean water from various waters. The proposed PRO−MD system may possess unique advantages of high water recovery rate, huge osmotic power generation, well controlled membrane fouling, and minimal environmental impacts. Experimental results show that the PRO−MD hybrid process is promising that not only can harvest osmotic energy from freshwater but also from wastewater. When employing a 2 M NaCl MD concentrate as the draw solution, ultrahigh power densities of 31.0 W/m2 and 9.3 W/m2 have been demonstrated by the PRO subsystem using deionized water and real wastewater brine as the feeds, respectively. Simultaneously, high purity potable water with a flux of 32.5−63.1 L/(m2.h) can be produced by the MD subsystem at 40−60 °C without any detrimental effects of fouling. The energy consumption in the MD subsystem might be further reduced by applying a heat exchanger in the hybrid system and using low-grade heat or solar energy to heat up the feed solution. The newly developed PRO−MD hybrid process would provide insightful guidelines for the exploration of alternative green technologies for renewable osmotic energy and clean water production.

Structure and morphology controllable synthesis of Ag/carbon hybrid with ionic liquid as soft-template and their catalytic properties

International Nuclear Information System (INIS)

Wu Shuying; Ding Yunsheng; Zhang Xiaomin; Tang Haiou; Chen Long; Li Boxuan

2008-01-01

Ag/carbon hybrids were fabricated by the redox of glucose and silver nitrate (AgNO 3 ) in the presence of imidazolium ionic liquid ([C 14 mim]BF 4 ) under hydrothermal condition. Monodisperse carbon hollow sub-microspheres encapsulating Ag nanoparticles and Ag/carbon cables were selectively prepared by varying the concentration of ionic liquid. Other reaction parameters, such as reaction temperature, reaction time and the mole ratio of silver nitrate to glucose, play important roles in controlling the structures of the products. The products were characterized by XRD, TEM (HRTEM), SEM, energy-dispersive X-ray spectroscopy (EDX), FTIR spectroscopy and a Raman spectrometer. The possible formation mechanism was proposed. The catalytic property of the hybrid in the oxidation of 1-butanol by H 2 O 2 was also investigated. - Graphical abstract: Monodisperse carbon hollow nanospheres encapsulating Ag nanoparticles and Ag/carbon nanocables were selectively prepared with ionic liquids as the soft-template. The controllable synthesis of Ag/C nano-hybrids was realized by varying the concentration of ionic liquids, reaction temperature, reaction time and the mole ratio of silver nitrate to glucose. The catalysis of Ag/C nano-hybrid in the oxidation of 1-butanol by H 2 O 2 was also investigated

A highly sensitive hydrogen sensor with gas selectivity using a PMMA membrane-coated Pd nanoparticle/single-layer graphene hybrid.

Science.gov (United States)

Hong, Juree; Lee, Sanggeun; Seo, Jungmok; Pyo, Soonjae; Kim, Jongbaeg; Lee, Taeyoon

2015-02-18

A polymer membrane-coated palladium (Pd) nanoparticle (NP)/single-layer graphene (SLG) hybrid sensor was fabricated for highly sensitive hydrogen gas (H2) sensing with gas selectivity. Pd NPs were deposited on SLG via the galvanic displacement reaction between graphene-buffered copper (Cu) and Pd ion. During the galvanic displacement reaction, graphene was used as a buffer layer, which transports electrons from Cu for Pd to nucleate on the SLG surface. The deposited Pd NPs on the SLG surface were well-distributed with high uniformity and low defects. The Pd NP/SLG hybrid was then coated with polymer membrane layer for the selective filtration of H2. Because of the selective H2 filtration effect of the polymer membrane layer, the sensor had no responses to methane, carbon monoxide, or nitrogen dioxide gas. On the contrary, the PMMA/Pd NP/SLG hybrid sensor exhibited a good response to exposure to 2% H2: on average, 66.37% response within 1.81 min and recovery within 5.52 min. In addition, reliable and repeatable sensing behaviors were obtained when the sensor was exposed to different H2 concentrations ranging from 0.025 to 2%.

Biomimetic Hybridization of Kevlar into Silk Fibroin: Nanofibrous Strategy for Improved Mechanic Properties of Flexible Composites and Filtration Membranes.

Science.gov (United States)

Lv, Lili; Han, Xiangsheng; Zong, Lu; Li, Mingjie; You, Jun; Wu, Xiaochen; Li, Chaoxu

2017-08-22

Silk, one of the strongest natural biopolymers, was hybridized with Kevlar, one of the strongest synthetic polymers, through a biomimetic nanofibrous strategy. Regenerated silk materials have outstanding properties in transparency, biocompatibility, biodegradability and sustainability, and promising applications as diverse as in pharmaceutics, electronics, photonic devices and membranes. To compete with super mechanic properties of their natural counterpart, regenerated silk materials have been hybridized with inorganic fillers such as graphene and carbon nanotubes, but frequently lose essential mechanic flexibility. Inspired by the nanofibrous strategy of natural biomaterials (e.g., silk fibers, hemp and byssal threads of mussels) for fantastic mechanic properties, Kevlar was integrated in regenerated silk materials by combining nanometric fibrillation with proper hydrothermal treatments. The resultant hybrid films showed an ultimate stress and Young's modulus two times as high as those of pure regenerated SF films. This is not only because of the reinforcing effect of Kevlar nanofibrils, but also because of the increasing content of silk β-sheets. When introducing Kevlar nanofibrils into the membranes of silk nanofibrils assembled by regenerated silk fibroin, the improved mechanic properties further enabled potential applications as pressure-driven nanofiltration membranes and flexible substrates of electronic devices.

Drug loaded homogeneous electrospun PCL/gelatin hybrid nanofiber structures for anti-infective tissue regeneration membranes.

Science.gov (United States)

Xue, Jiajia; He, Min; Liu, Hao; Niu, Yuzhao; Crawford, Aileen; Coates, Phil D; Chen, Dafu; Shi, Rui; Zhang, Liqun

2014-11-01

Infection is the major reason for guided tissue regeneration/guided bone regeneration (GTR/GBR) membrane failure in clinical application. In this work, we developed GTR/GBR membranes with localized drug delivery function to prevent infection by electrospinning of poly(ε-caprolactone) (PCL) and gelatin blended with metronidazole (MNA). Acetic acid (HAc) was introduced to improve the miscibility of PCL and gelatin to fabricate homogeneous hybrid nanofiber membranes. The effects of the addition of HAc and the MNA content (0, 1, 5, 10, 20, 30, and 40 wt.% of polymer) on the properties of the membranes were investigated. The membranes showed good mechanical properties, appropriate biodegradation rate and barrier function. The controlled and sustained release of MNA from the membranes significantly prevented the colonization of anaerobic bacteria. Cells could adhere to and proliferate on the membranes without cytotoxicity until the MNA content reached 30%. Subcutaneous implantation in rabbits for 8 months demonstrated that MNA-loaded membranes evoked a less severe inflammatory response depending on the dose of MNA than bare membranes. The biodegradation time of the membranes was appropriate for tissue regeneration. These results indicated the potential for using MNA-loaded PCL/gelatin electrospun membranes as anti-infective GTR/GBR membranes to optimize clinical application of GTR/GBR strategies. Copyright © 2014 Elsevier Ltd. All rights reserved.

Engineering lipid structure for recognition of the liquid ordered membrane phase

International Nuclear Information System (INIS)

Bordovsky, Stefan S.; Wong, Christopher S.; Bachand, George D.; Stachowiak, Jeanne C.; Sasaki, Darryl Y.

2016-01-01

The selective partitioning of lipid components in phase-separated membranes is essential for domain formation involved in cellular processes. Identifying and tracking the movement of lipids in cellular systems would be improved if we understood how to achieve selective affinity between fluorophore-labeled lipids and membrane assemblies. Furthermore, we investigated the structure and chemistry of membrane lipids to evaluate lipid designs that partition to the liquid ordered (L_o) phase. A range of fluorophores at the headgroup position and lengths of PEG spacer between the lipid backbone and fluorophore were examined. On a lipid body with saturated palmityl or palmitoyl tails, we found that although the lipid tails can direct selective partitioning to the L_o phase through favorable packing interactions, headgroup hydrophobicity can override the partitioning behavior and direct the lipid to the disordered membrane phase (L_d). The PEG spacer can serve as a buffer to mute headgroup–membrane interactions and thus improve L_o phase partitioning, but its effect is limited with strongly hydrophobic fluorophore headgroups. We present a series of lipid designs leading to the development of novel fluorescently labeled lipids with selective affinity for the L_o phase.

Hybrid systems with lead-acid battery and proton-exchange membrane fuel cell

Science.gov (United States)

Jossen, Andreas; Garche, Juergen; Doering, Harry; Goetz, Markus; Knaupp, Werner; Joerissen, Ludwig

Hybrid systems, based on a lead-acid battery and a proton-exchange membrane fuel cell (PEMFC) give the possibility to combine the advantages of both technologies. The benefits for different applications are discussed and the practical realisation of such systems is shown. Furthermore a numerical model for such a hybrid system is described and results are shown and discussed. The results show that the combination of lead-acid batteries and PEMFC shows advantages in case of applications with high peak power requirements (i.e. electric scooter) and applications where the fuel cell is used as auxiliary power supply to recharge the battery. The high efficiency of fuel cells at partial load operation results in a good fuel economy for recharging of lead-acid batteries with a fuel cell system.

In-situ Non-Invasive Imaging of Liquid-Immersed Thin Film Composite Membranes

KAUST Repository

Ogieglo, Wojciech

2017-10-14

We present a non-invasive method to directly image liquid-immersed thin film composite membranes. The approach allows accessing information not only on the lateral distribution of the coating thickness, including variations in its swelling and density, but also on the distribution of substrate porosity, roughness, accessibility of pores to liquid, and even the degree of pore intrusion related to the thin layer deposition process. The method can be particularly helpful in the fields of functional coatings or membranes to allow laterally-resolved studies under realistic application conditions thereby opening completely new research avenues. The approach is demonstrated in a study of two polymers of intrinsic microporosity, PIM-1 and PIM-6FDA-OH, coated on polyacrylonitrile support and immersed in water. Variations of the skin morphology using different coating methods (floating, spin-coating and dip-coating) are evaluated with the help of the presented method. Surfaces of at least tens of cm2 can be potentially analyzed.

Study on removal of cadmium from wastewater by emulsion liquid membrane

International Nuclear Information System (INIS)

Mortaheb, Hamid R.; Kosuge, Hitoshi; Mokhtarani, Babak; Amini, Mohammad H.; Banihashemi, Hamid R.

2009-01-01

Removal of cadmium from wastewater using emulsion liquid membrane (ELM) is studied in the present study. A polyamine-type surfactant was used for stabilizing the emulsion phase. Tri-iso-octyl amine (TIOA) has been used as a carrier for transferring of cadmium through the membrane. The results show good performance in the separation process. To determine the optimum operation conditions, the effect of several parameters such as surfactant concentration, carrier concentration, pH of external and internal phases, oil to internal phase volume ratio, emulsion to external phase volume ratio, solvent type, solute concentration, presence of iodide and chloride in external phase, and mixing conditions have been investigated.

An adaptive self-healing ionic liquid nanocomposite membrane for olefin-paraffin separations.

Science.gov (United States)

Pitsch, Fee; Krull, Florian F; Agel, Friederike; Schulz, Peter; Wasserscheid, Peter; Melin, Thomas; Wessling, Matthias

2012-08-16

An adaptive self-healing ionic liquid nanocomposite membrane comprising a multi-layer support structure hosting the ionic salt [Ag](+) [Tf(2) N](-) is used for the separation of the olefin propylene and the paraffin propane. The ionic salt renders liquid like upon complexation with propylene, resulting in facilitated transport of propylene over propane at benchmark-setting selectivity and permeance levels. The contacting with acetylene causes the ionic salt to liquefy without showing evidence of forming explosive silver acetylide. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The effect of peptides and ions interacting with an electrically neutral membrane interface on the structure and stability of lipid membranes in the liquid-crystalline phase and in the liquid-ordered phase

Energy Technology Data Exchange (ETDEWEB)

Sano, Ryoko [Department of Physics, Faculty of Science, Shizuoka University, Shizuoka, 422-8529 (Japan); Masum, Shah Md [Material Science, Graduate School of Science and Engineering, Shizuoka University, 422-8529 (Japan); Tanaka, Tomoki [Material Science, Graduate School of Science and Engineering, Shizuoka University, 422-8529 (Japan); Yamashita, Yuko [Department of Physics, Faculty of Science, Shizuoka University, Shizuoka, 422-8529 (Japan); Levadny, Victor [Department of Physics, Faculty of Science, Shizuoka University, Shizuoka, 422-8529 (Japan); Scientific Council for Cybernetics, Russian Academy of Sciences, Vavilov street 34, 333117, Moscow (Russian Federation); Yamazaki, Masahito [Department of Physics, Faculty of Science, Shizuoka University, Shizuoka, 422-8529 (Japan); Material Science, Graduate School of Science and Engineering, Shizuoka University, 422-8529 (Japan)

2005-08-10

We investigated the effects of a de novo designed peptide, WLFLLKKK (peptide-1) and La{sup 3+}, which can bind with the electrically neutral lipid membrane interface, on the stability of the phosphatidylcholine (PC) membrane in the L{sub {alpha}} phase and that of the liquid-ordered (lo) phase membranes. The results of spacing of the multilamellar vesicle and shape changes of the giant unilamellar vesicle (GUV) indicate that the peptide-1 can be partitioned into the membrane interface in the L{sub {alpha}} phase but not into that in the lo phase. La{sup 3+} induced shape changes of GUVs of the lo phase membrane, which are the same as those of GUVs in the L{sub {alpha}} phase. This indicates that the binding of La{sup 3+} induced an increase in the lateral compression pressure of the membrane, which decreased the surface area of the membrane in the lo phase. The difference of the membrane interface between the L{sub {alpha}} phase and the lo phase is discussed.

An investigation of an uninterruptible power supply (UPS) based on supercapacitor and liquid nitrogen hybridization system

International Nuclear Information System (INIS)

Zhang, Xinjing; Xue, Haobai; Xu, Yujie; Chen, Haisheng; Tan, Chunqing

2014-01-01

Highlights: • A hybrid UPS based on supercapacitor and liquid nitrogen engine is proposed. • The dynamic modelling of the hybrid UPS system is conducted. • The dynamic working performance is obtained and analysed based on the simulation. • The hybrid UPS enjoys environmental benignity, long life and easy maintenance. • It is a highly possible solution to replace conventional UPS systems. - Abstract: An uninterruptible power supply (UPS) system based on supercapacitor and liquid nitrogen (LN 2 ) hybridization is first introduced in this paper. Of the newly designed UPS, the supercapacitor reacts instantaneously once the main supply fails, and it also starts the LN 2 power system to produce continuing electricity for the customer. This hybrid UPS system is of environment cleanness, long life time, easy maintenaince, etc. A 10 kW model is analyzed in this study. A two-stage nitrogen expander is designed with the rated speed of 900 rpm as the long time power generation device of the LN 2 cycle. The UPS starting process calculation is carried out. The results reveal that commercial supercapacitors could fulfill this request. This UPS could be a competent choice for the UPS application. Further discussion indicates the LN 2 power system could be used widely from UPS to low carbon vehicles

Keyhole behavior and liquid flow in molten pool during laser-arc hybrid welding

Science.gov (United States)

Naito, Yasuaki; Katayama, Seiji; Matsunawa, Akira

2003-03-01

Hybrid welding was carried out on Type 304 stainless steel plate under various conditions using YAG laser combined with TIG arc. During arc and laser-arc hybrid welding, arc voltage variation was measured, and arc plasma, laser-induced plume and evaporation spots as well as keyhole behavior and liquid flow in the molten pool were observed through CCD camera and X-ray real-time transmission apparatus. It was consequently found that hybrid welding possessed many features in comparison with YAG laser welding. The deepest weld bead could be produced when the YAG laser beam of high power density was shot on the molten pool made beforehand stably with TIG arc. A keyhole was long and narrow, and its behavior was rather stable inside the molten pool. It was also confirmed that porosity was reduced by the suppression of bubble formation in hybrid welding utilizing a laser of a moderate power density.

Nafion–clay hybrids with a network structure

KAUST Repository

Burgaz, Engin; Lian, Huiqin; Alonso, Rafael Herrera; Estevez, Luis; Kelarakis, Antonios; Giannelis, Emmanuel P.

2009-01-01

Nafion-clay hybrid membranes with a unique microstructure were synthesized using a fundamentally new approach. The new approach is based on depletion aggregation of suspended particles - a well-known phenomenon in colloids. For certain concentrations of clay and polymer, addition of Nafion solution to clay suspensions in water leads to a gel. Using Cryo-TEM we show that the clay particles in the hybrid gels form a network structure with an average cell size in the order of 500 nm. The hybrid gels are subsequently cast to produce hybrid Nafion-clay membranes. Compared to pure Nafion the swelling of the hybrid membranes in water and methanol is dramatically reduced while their selectivity (ratio of conductivity over permeability) increases. The small decrease of ionic conductivity for the hybrid membranes is more than compensated by the large decrease in methanol permeability. Lastly the hybrid membranes are much stiffer and can withstand higher temperatures compared to pure Nafion. Both of these characteristics are highly desirable for use in fuel cell applications, since a) they will allow the use of a thinner membrane circumventing problems associated with the membrane resistance and b) enable high temperature applications. © 2009 Elsevier Ltd. All rights reserved.

Nafion–clay hybrids with a network structure

KAUST Repository

Burgaz, Engin

2009-05-01

Nafion-clay hybrid membranes with a unique microstructure were synthesized using a fundamentally new approach. The new approach is based on depletion aggregation of suspended particles - a well-known phenomenon in colloids. For certain concentrations of clay and polymer, addition of Nafion solution to clay suspensions in water leads to a gel. Using Cryo-TEM we show that the clay particles in the hybrid gels form a network structure with an average cell size in the order of 500 nm. The hybrid gels are subsequently cast to produce hybrid Nafion-clay membranes. Compared to pure Nafion the swelling of the hybrid membranes in water and methanol is dramatically reduced while their selectivity (ratio of conductivity over permeability) increases. The small decrease of ionic conductivity for the hybrid membranes is more than compensated by the large decrease in methanol permeability. Lastly the hybrid membranes are much stiffer and can withstand higher temperatures compared to pure Nafion. Both of these characteristics are highly desirable for use in fuel cell applications, since a) they will allow the use of a thinner membrane circumventing problems associated with the membrane resistance and b) enable high temperature applications. © 2009 Elsevier Ltd. All rights reserved.

Thinning of reverse osmosis membranes by ionic liquids

Energy Technology Data Exchange (ETDEWEB)

Meng, Hong, E-mail: menghong@mail.buct.edu.cn; Gong, Beibei; Geng, Tao; Li, Chunxi

2014-02-15

In this study, ionic liquids (ILs) were used to thin out the dense layer and, in turn, tune the surface properties and separation performance of commercial aromatic polyamide reverse osmosis membranes. It was observed that the structure of the ILs and dipping time had a strong impact on the dense layer thickness and morphology. This can be understood in terms of the dissolubility and interaction force between ILs and the organic membrane surface, such as hydrogen bonding and π–π interactions. Among the ILs synthesized, 1-butyl-3-methylimidazolium chloride ([BMIM]Cl) showed the most promising thinning effects. It was observed that the thickness of the dense layer on the surface decreased from 127 to 67 nm after dipping treatment with [BMIM]Cl for 24 h. The water flux was enhanced by 20% at the expense of a slight decline of salt rejection. AFM, contact angle and zeta potential analyses suggest that the surface hydrophilicity and electronegativity increased, while the roughness decreased, which improved the anti-fouling properties.

utilization of adsorption and/or liquid membranes techniques in treatment of some hazardous substances

International Nuclear Information System (INIS)

Hussin, L.M.S.

2011-01-01

environmental pollution, as a consequence of the industrialization process, is one of the major problems that has to be solved and controlled. The most important treatment processes for metals and dyes contaminated waste streams include chemical precipitation, membrane, filtration, ion exchange, carbon adsorption and coprecipitation/adsorption. However, all these techniques have their inherent advantages and limitations in applications. These processes usually need expensive facility and high maintenance cost. Therefore, there is a need for more economical alternative technologies for the treatment of metals and dyes contaminated waste streams. The aim of present work is to study the treatment of some hazardous substances such as heavy metals e.g. ( lead, cobalt and strontium) and dyes e.g. ( acid red 73, and acid blue 74 ) using either adsorption or liquid emulsion membrane techniques. The experimental part deals with the application of adsorption and liquid emulsion membrane techniques for removal of some hazardous substances such as metal ions ( lead, cobalt and strontium) and dyes (acid red 73 and acid blue 74). All the apparatus and techniques employed were described.

Mesoporous silica nanotubes hybrid membranes for functional nanofiltration

International Nuclear Information System (INIS)

El-Safty, Sherif A; Shahat, Ahmed; Mekawy, Moataz; Nguyen, Hoa; Warkocki, Wojciech; Ohnuma, Masato

2010-01-01

The development of nanofiltration systems would greatly assist in the production of well-defined particles and biomolecules with unique properties. We report a direct, simple synthesis of hexagonal silica nanotubes (NTs), which vertically aligned inside anodic alumina membranes (AAM) by means of a direct templating method of microemulsion phases with cationic surfactants. The direct approach was used as soft templates for predicting ordered assemblies of surfactant/silica composites through strong interactions within AAM pockets. Thus, densely packed NTs were successfully formed in the entirety of the AAM channels. These silica NTs were coated with layers of organic moieties to create a powerful technique for the ultrafine filtration. The resulting modified-silica NTs were chemically robust and showed affinity toward the transport of small molecular particles. The rigid silica NTs inside AAM channels had a pore diameter of ≤ 4 nm and were used as ultrafine filtration systems for noble metal nanoparticles (NM NPs) and semiconductor nanocrystals (SC NCs) fabricated with a wide range of sizes (1.0-50 nm) and spherical/pyramidal morphologies. Moreover, the silica NTs hybrid membranes were also found to be suitable for separation of biomolecules such as cytochrome c (CytC). Importantly, this nanofilter design retains high nanofiltration efficiency of NM NPs, SC NCs and biomolecules after a number of reuse cycles. Such retention is crucial in industrial applications.

Pertraction of Penicillin G in Hollow Fiber Contained Liquid Membranes

International Nuclear Information System (INIS)

Miesiac, I.; Szymanowski, J.

1998-01-01

Pertraction of Penicillin G in Hollow Fiber Contained Liquid Membranes was investigated in a system consisting of 2 Liqui Cel 106 modules from Hoechst Celanese. The flux of Pen G depended upon the content of n-octanol and of Amberlite LA2 in kerosene used as a membrane phase. During the pertraction of Pen G in HFCLM system the pH difference between the both buffered aqueous phases diminished proportionally to the contact time with the membrane phase. The flux of citric acid used as a buffer component in the feed phase attained 11.8 mM/m 2 x h and was comparable with the flux of Pen G equal to 18.4 mM/m 2 x h. In order to eliminate the undesired transport of citric acid, CO 2 was used as a volatile buffer component. Although the pH values were stabilised in the range of 5.47 and 7.45 in the feed and strip phase, respectively, the achieved Pen G flux was significantly lower. (author)

Steady-state coupled transport of HNO3 through a hollow-fiber supported liquid membrane

International Nuclear Information System (INIS)

Noble, R.D.; Danesi, P.R.

1987-01-01

Nitric acid removal from an aqueous stream was accomplished by continuously passing the fluid through a hollow fiber supported liquid membrane (SLM). The nitric acid was extracted through the membrane wall by coupled transport. The system was modeled as a series of (SLM)-continuous stirred tank reactor (CSTR) pairs. An approximate technique was used to predict the steady state nitric acid concentration in the system. The comparison with experimental data was very good

Network and neuronal membrane properties in hybrid networks reciprocally regulate selectivity to rapid thalamocortical inputs.

Science.gov (United States)

Pesavento, Michael J; Pinto, David J

2012-11-01

Rapidly changing environments require rapid processing from sensory inputs. Varying deflection velocities of a rodent's primary facial vibrissa cause varying temporal neuronal activity profiles within the ventral posteromedial thalamic nucleus. Local neuron populations in a single somatosensory layer 4 barrel transform sparsely coded input into a spike count based on the input's temporal profile. We investigate this transformation by creating a barrel-like hybrid network with whole cell recordings of in vitro neurons from a cortical slice preparation, embedding the biological neuron in the simulated network by presenting virtual synaptic conductances via a conductance clamp. Utilizing the hybrid network, we examine the reciprocal network properties (local excitatory and inhibitory synaptic convergence) and neuronal membrane properties (input resistance) by altering the barrel population response to diverse thalamic input. In the presence of local network input, neurons are more selective to thalamic input timing; this arises from strong feedforward inhibition. Strongly inhibitory (damping) network regimes are more selective to timing and less selective to the magnitude of input but require stronger initial input. Input selectivity relies heavily on the different membrane properties of excitatory and inhibitory neurons. When inhibitory and excitatory neurons had identical membrane properties, the sensitivity of in vitro neurons to temporal vs. magnitude features of input was substantially reduced. Increasing the mean leak conductance of the inhibitory cells decreased the network's temporal sensitivity, whereas increasing excitatory leak conductance enhanced magnitude sensitivity. Local network synapses are essential in shaping thalamic input, and differing membrane properties of functional classes reciprocally modulate this effect.

Solute Transport from Aqueous Mixture through Supported Ionic Liquid Membrane by Pervaporation.

Czech Academy of Sciences Publication Activity Database

Izák, Pavel; Koekerling, M.; Kragl, U.

2006-01-01

Roč. 199, 1-3 (2006) , s. 96–98 ISSN 0011-9164. [Euromembrane 2006. Giardini, Naxos, 24.09.2006-28.09.2006] Institutional research plan: CEZ:AV0Z40720504 Keywords : supported ionic liquid membrane * pervaporation * 1,3-propanediol Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 0.917, year: 2006

A New Hybrid Proton-Exchange-Membrane Fuel Cells-Battery Power System with Efficiencies Considered

Science.gov (United States)

Chao, Chung-Hsing; Shieh, Jenn-Jong

Hybrid systems, based on lead-acid or lithium-ion batteries and proton-exchange-membrane fuel cells (PEMFCs), give the possibility of combining the benefit of both technologies. The merits of high energy density and power density for different applications are discussed in this paper in recognition of the practical realization of such hybrid power systems. Furthermore, experimental data for such a hybrid system is described and the results are shown and discussed. The results show that the combination of lead-acid batteries or lithium-ion batteries and PEMFCs shows advantages in cases of applications with high peak power requirements, such as electric scooters and applications where the fuel cell (FC) is used as an auxiliary power-supply to recharge the battery. The high efficiency of FCs operating with a partial load results in a good fuel economy for the purpose of recharging batteries within a FC system.

The Effect of Reactive Ionic Liquid or Plasticizer Incorporation on the Physicochemical and Transport Properties of Cellulose Acetate Propionate-Based Membranes

Directory of Open Access Journals (Sweden)

Edyta Rynkowska

2018-01-01

Full Text Available Pervaporation is a membrane-separation technique which uses polymeric and/or ceramic membranes. In the case of pervaporation processes applied to dehydration, the membrane should transport water molecules preferentially. Reactive ionic liquid (RIL (3-(1,3-diethoxy-1,3-dioxopropan-2-yl-1-methyl-1H-imidazol-3-ium was used to prepare novel dense cellulose acetate propionate (CAP based membranes, applying the phase-inversion method. The designed polymer-ionic liquid system contained ionic liquid partially linked to the polymeric structure via the transesterification reaction. The various physicochemical, mechanical, equilibrium and transport properties of CAP-RIL membranes were determined and compared with the properties of CAP membranes modified with plasticizers, i.e., tributyl citrate (TBC and acetyl tributyl citrate (ATBC. Thermogravimetric analysis (TGA testified that CAP-RIL membranes as well as CAP membranes modified with TBC and ATBC are thermally stable up to at least 120 °C. Tensile tests of the membranes revealed improved mechanical properties reflected by reduced brittleness and increased elongation at break achieved for CAP-RIL membranes in contrast to pristine CAP membranes. RIL plasticizes the CAP matrix, and CAP-RIL membranes possess preferable mechanical properties in comparison to membranes with other plasticizers investigated. The incorporation of RIL into CAP membranes tuned the surface properties of the membranes, enhancing their hydrophilic character. Moreover, the addition of RIL into CAP resulted in an excellent improvement of the separation factor, in comparison to pristine CAP membranes, in pervaporation dehydration of propan-2-ol. The separation factor β increased from ca. 10 for pristine CAP membrane to ca. 380 for CAP-16.7-RIL membranes contacting an azeotropic composition of water-propan-2-ol mixture (i.e., 12 wt % water.

Mass transfer modeling on the separation of tantalum and niobium from dilute hydrofluoric media through a hollow fiber supported liquid membrane

International Nuclear Information System (INIS)

Buachuang, Duenphen; Ramakul, Prakorn; Leepipatpiboon, Natchanun; Pancharoen, Ura

2011-01-01

Highlights: → Simultaneous separation of tantalum and niobium from the mixture solution. → An extraction through a hollow fiber supported liquid membrane (HFSLM). → The effect on tantalum removal found from Aliquat 336. → The mathematical model focusing on the extraction side of the liquid membrane system was presented. → The mass transfer coefficients of the aqueous feed (k i ) and the organic membrane phase (k m ) for the system were estimated as 1.19 x 10 -5 and 1.39 x 10 -7 cm/s, respectively. → Experimental data and theoretical values were found to be in good agreement when the concentration of Aliquat336 in the membrane phase was below 4% (v/v). - Abstract: The separation of a mixture of tantalum and niobium in dilute hydrofluoric media via hollow fiber supported liquid membrane (HFSLM) was examined. Quaternary ammonium salt (Aliquat336) diluted in kerosene was used as a carrier. The various effects on the transport and separation of tantalum and niobium were studied: concentration of hydrofluoric acid in the feed solution, concentration of the carrier (Aliquat336) in the membrane phase, types of stripping solutions (NaClO 4 , thiourea and HCl) and their concentration. The extraction of tantalum in the membrane phase from 0.3 M hydrofluoric acid (HF) by 3% (v/v) Aliquat336 was achieved by leaving niobium in the feed solution. Quantitative recovery of tantalum was achieved by 0.2 M NaClO 4 . Furthermore, a mathematical model focusing on the extraction side of the liquid membrane system was presented in order to predict the concentration of tantalum at different times. The mass transfer coefficients of the aqueous feed (k i ) and the organic membrane phase (k m ) were estimated as 1.19 x 10 -5 and 1.39 x 10 -7 cm/s, respectively. Therefore, the mass transfer limiting step is the diffusion of tantalum-Aliquat336 through the liquid membrane. Moreover, mass transfer modeling was performed and the validity of the developed model evaluated. Experimental

Mass transfer modeling on the separation of tantalum and niobium from dilute hydrofluoric media through a hollow fiber supported liquid membrane

Energy Technology Data Exchange (ETDEWEB)

Buachuang, Duenphen [Department of Chemical Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok 10330 (Thailand); Ramakul, Prakorn [Department of Chemical Engineering, Faculty of Engineering and Industrial Technology, Silpakorn University, Nakhon Pathom 73000 (Thailand); Leepipatpiboon, Natchanun [Chromatography and Separation Research Unit, Department of Chemistry, Faculty of Science, Chulalongkorn University, Patumwan, Bangkok 10330 (Thailand); Pancharoen, Ura, E-mail: ura.p.@chula.ac.th [Department of Chemical Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok 10330 (Thailand)

2011-09-29

Highlights: > Simultaneous separation of tantalum and niobium from the mixture solution. > An extraction through a hollow fiber supported liquid membrane (HFSLM). > The effect on tantalum removal found from Aliquat 336. > The mathematical model focusing on the extraction side of the liquid membrane system was presented. > The mass transfer coefficients of the aqueous feed (k{sub i}) and the organic membrane phase (k{sub m}) for the system were estimated as 1.19 x 10{sup -5} and 1.39 x 10{sup -7} cm/s, respectively. > Experimental data and theoretical values were found to be in good agreement when the concentration of Aliquat336 in the membrane phase was below 4% (v/v). - Abstract: The separation of a mixture of tantalum and niobium in dilute hydrofluoric media via hollow fiber supported liquid membrane (HFSLM) was examined. Quaternary ammonium salt (Aliquat336) diluted in kerosene was used as a carrier. The various effects on the transport and separation of tantalum and niobium were studied: concentration of hydrofluoric acid in the feed solution, concentration of the carrier (Aliquat336) in the membrane phase, types of stripping solutions (NaClO{sub 4}, thiourea and HCl) and their concentration. The extraction of tantalum in the membrane phase from 0.3 M hydrofluoric acid (HF) by 3% (v/v) Aliquat336 was achieved by leaving niobium in the feed solution. Quantitative recovery of tantalum was achieved by 0.2 M NaClO{sub 4}. Furthermore, a mathematical model focusing on the extraction side of the liquid membrane system was presented in order to predict the concentration of tantalum at different times. The mass transfer coefficients of the aqueous feed (k{sub i}) and the organic membrane phase (k{sub m}) were estimated as 1.19 x 10{sup -5} and 1.39 x 10{sup -7} cm/s, respectively. Therefore, the mass transfer limiting step is the diffusion of tantalum-Aliquat336 through the liquid membrane. Moreover, mass transfer modeling was performed and the validity of the

Preparation and evaluation of a novel hybrid monolithic column based on pentafluorobenzyl imidazolium bromide ionic liquid.

Science.gov (United States)

Shan, Yuanhong; Qiao, Lizhen; Shi, Xianzhe; Xu, Guowang

2015-01-02

To develop a novel hybrid monolithic column based on pentafluorobenzyl imidazolium bromide ionic liquid, a new ionic liquid monomer was synthesized from 1-vinylimidazole and pentafluorobenzyl bromide. By employing a facile one-step copolymerization of polyhedral-oligomeric-silsesquioxane-type (POSS) cross-linking agent and the home-made ionic liquid monomer, the hybrid monolithic columns were in situ fabricated in fused-silica capillary. The morphology of monolithic column was characterized by scanning electron microscope (SEM) and the chemical composition was confirmed by Fourier-transform infrared spectroscopy (FT-IR) and elemental analysis. Excellent mechanical stability and slight swelling propensity were exhibited which was ascribed to the rigid hybrid monolithic skeleton. Reproducibility results of run-to-run, column-to-column, batch-to-batch and day-to-day were investigated and the RSDs were less than 0.46%, 1.84%, 3.96% and 3.17%, respectively. The mixed-mode retention mechanism with hydrophobic interaction, π-π stacking, ion-exchange, electrostatic interaction and dipole-dipole interaction was explored systematically using analytes with different structure types. Satisfied separation capability and column efficiency were achieved for the analysis of small molecular compounds such as alkylbenzenes, polycyclic aromatic hydrocarbons, nucleosides and halogenated compounds. Copyright © 2014 Elsevier B.V. All rights reserved.

Transport of Eu3+ through a Bis(2-ethylhexyl)-phosphoric acid, n-dodecane solid supported liquid membrane

International Nuclear Information System (INIS)

Danesi, P.R.; Horwitz, E.P.; Rickert, P.

1982-01-01

The coupled transpot of Eu 3 + and H + ions througn a solid supported liquid membrane consisting of a porous polypropylene film immobilizing an HDEHP solution in n-dodecane has been studied as a function of the membrane area, stirring speed of the aqueous solutions, membrane composition, and acidity of the feed solution. The experimental results are in agreement with predictions derived from a theoretical permeability coefficient equation which assumes that membrane diffusion and aqueous film diffusion are the only rate-controlling factors

A novel integrated thermal-/membrane-based solar energy-driven hybrid desalination system: Concept description and simulation results.

Science.gov (United States)

Kim, Young-Deuk; Thu, Kyaw; Ng, Kim Choon; Amy, Gary L; Ghaffour, Noreddine

2016-09-01

In this paper, a hybrid desalination system consisting of vacuum membrane distillation (VMD) and adsorption desalination (AD) units, designated as VMD-AD cycle, is proposed. The synergetic integration of the VMD and AD is demonstrated where a useful effect of the AD cycle is channelled to boost the operation of the VMD process, namely the low vacuum environment to maintain the high pressure gradient across the microporous hydrophobic membrane. A solar-assisted multi-stage VMD-AD hybrid desalination system with temperature modulating unit is first designed, and its performance is then examined with a mathematical model of each component in the system and compared with the VMD-only system with temperature modulating and heat recovery units. The total water production and water recovery ratio of a solar-assisted 24-stage VMD-AD hybrid system are found to be about 21% and 23% higher, respectively, as compared to the VMD-only system. For the solar-assisted 24-stage VMD-AD desalination system having 150 m(2) of evacuated-tube collectors and 10 m(3) seawater storage tanks, both annual collector efficiency and solar fraction are close to 60%. Copyright © 2016 Elsevier Ltd. All rights reserved.

A novel integrated thermal-/membrane-based solar energy-driven hybrid desalination system: Concept description and simulation results

KAUST Repository

Kim, Youngdeuk

2016-05-03

In this paper, a hybrid desalination system consisting of vacuum membrane distillation (VMD) and adsorption desalination (AD) units, designated as VMD-AD cycle, is proposed. The synergetic integration of the VMD and AD is demonstrated where a useful effect of the AD cycle is channelled to boost the operation of the VMD process, namely the low vacuum environment to maintain the high pressure gradient across the microporous hydrophobic membrane. A solar-assisted multi-stage VMD-AD hybrid desalination system with temperature modulating unit is first designed, and its performance is then examined with a mathematical model of each component in the system and compared with the VMD-only system with temperature modulating and heat recovery units. The total water production and water recovery ratio of a solar-assisted 24-stage VMD-AD hybrid system are found to be about 21% and 23% higher, respectively, as compared to the VMD-only system. For the solar-assisted 24-stage VMD-AD desalination system having 150 m2 of evacuated-tube collectors and 10 m3 seawater storage tanks, both annual collector efficiency and solar fraction are close to 60%.

Gas-liquid hybrid discharge-induced degradation of diuron in aqueous solution.

Science.gov (United States)

Feng, Jingwei; Zheng, Zheng; Luan, Jingfei; Li, Kunquan; Wang, Lianhong; Feng, Jianfang

2009-05-30

Degradation of diuron in aqueous solution by gas-liquid hybrid discharge was investigated for the first time. The effect of output power intensity, pH value, Fe(2+) concentration, Cu(2+) concentration, initial conductivity and air flow rate on the degradation efficiency of diuron was examined. The results showed that the degradation efficiency of diuron increased with increasing output power intensity and increased with decreasing pH values. In the presence of Fe(2+), the degradation efficiency of diuron increased with increasing Fe(2+) concentration. The degradation efficiency of diuron was decreased during the first 4 min and increased during the last 10 min with adding of Cu(2+). Decreasing the initial conductivity and increasing the air flow rate were favorable for the degradation of diuron. Degradation of diuron by gas-liquid hybrid discharge fitted first-order kinetics. The pH value of the solution decreased during the reaction process. Total organic carbon removal rate increased in the presence of Fe(2+) or Cu(2+). The generated Cl(-1), NH(4)(+), NO(3)(-), oxalic acid, acetic acid and formic acid during the degradation process were also detected. Based on the detected Cl(-1) and other intermediates, a possible degradation pathway of diuron was proposed.

Treatment of coal gasification wastewater by membrane bioreactor hybrid powdered activated carbon (MBR–PAC) system.

Science.gov (United States)

Jia, Shengyong; Han, Hongjun; Hou, Baolin; Zhuang, Haifeng; Fang, Fang; Zhao, Qian

2014-12-01

A laboratory-scale membrane bioreactor hybrid powdered activated carbon (MBR–PAC) system was developed to treat coal gasification wastewater to enhance the COD, total phenols (TPh), NH4+ removals and migrate the membrane fouling. Since the MBR–PAC system operated with PAC dosage of 4 g L−1, the maximum removal efficiencies of COD, TPh and NH4+ reached 93%, 99% and 63%, respectively with the corresponding influent concentrations of 2.27 g L−1, 497 mg L−1 and 164 mg N L−1; the PAC extraction efficiencies of COD, TPh and NH4+ were 6%, 3% and 13%, respectively; the transmembrane pressure decreased 34% with PAC after 50 d operation. The results demonstrate that PAC played a key role in the enhancement of biodegradability and mitigation of membrane fouling.

Applicability of a Supported Liquid Membrane in the Enrichment and Determination of Cadmium from Complex Aqueous Samples

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Núria Pont

2018-04-01

Full Text Available A supported liquid membrane is developed for the separation of Cd from either high in salinity or acidity aqueous media. The membrane consisted of a durapore (polyvinylidene difluoride polymeric support impregnated with a 0.5 M Aliquat 336 solution in decaline. The effect of carrier concentration, organic solvent and feed and receiving solutions on the metal permeability is studied. This system allows the effective transport of trace levels of Cd through the formation of CdCl42−, which is the predominant species responsible for the extraction process, in both NaCl and HCl solutions. The supported liquid membrane system in a hollow fibre configuration allows the enrichment and separation of trace levels of Cd from spiked seawater samples, facilitating the analytical determination of this toxic metal.

Hybrid Processes Combining Photocatalysis and Ceramic Membrane Filtration for Degradation of Humic Acids in Saline Water.

Science.gov (United States)

Song, Lili; Zhu, Bo; Gray, Stephen; Duke, Mikel; Muthukumaran, Shobha

2016-03-01

This study explored the combined effects of photocatalysis with ceramic membrane filtration for the removal of humic acid in the presence of salt; to simulate saline wastewater conditions. The effects of operating parameters, such as salinity and TiO₂ concentration on permeate fluxes, total organic carbon (TOC), and UV absorbance removal, were investigated. The interaction between the humic acids and TiO₂ photocatalyst played an important role in the observed flux change during ceramic membrane filtration. The results for this hybrid system showed that the TOC removal was more than 70% for both without NaCl and with the 500 ppm NaCl concentration, and 62% and 66% for 1000 and 2000 ppm NaCl concentrations. The reduction in UV absorbance was more complete in the absence of NaCl compared to the presence of NaCl. The operation of the integrated photoreactor-ceramic membrane filter over five repeat cycles is described. It can be concluded that the overall removal performance of the hybrid system was influenced by the presence of salts, as salt leads to agglomeration of TiO₂ particles by suppressing the stabilising effects of electrostatic repulsion and thereby reduces the effective surface contact between the pollutant and the photocatalyst.

Hybrid Processes Combining Photocatalysis and Ceramic Membrane Filtration for Degradation of Humic Acids in Saline Water

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Lili Song

2016-03-01

Full Text Available This study explored the combined effects of photocatalysis with ceramic membrane filtration for the removal of humic acid in the presence of salt; to simulate saline wastewater conditions. The effects of operating parameters, such as salinity and TiO2 concentration on permeate fluxes, total organic carbon (TOC, and UV absorbance removal, were investigated. The interaction between the humic acids and TiO2 photocatalyst played an important role in the observed flux change during ceramic membrane filtration. The results for this hybrid system showed that the TOC removal was more than 70% for both without NaCl and with the 500 ppm NaCl concentration, and 62% and 66% for 1000 and 2000 ppm NaCl concentrations. The reduction in UV absorbance was more complete in the absence of NaCl compared to the presence of NaCl. The operation of the integrated photoreactor-ceramic membrane filter over five repeat cycles is described. It can be concluded that the overall removal performance of the hybrid system was influenced by the presence of salts, as salt leads to agglomeration of TiO2 particles by suppressing the stabilising effects of electrostatic repulsion and thereby reduces the effective surface contact between the pollutant and the photocatalyst.

Liquid contrabands classification based on energy dispersive X-ray diffraction and hybrid discriminant analysis

International Nuclear Information System (INIS)

YangDai, Tianyi; Zhang, Li

2016-01-01

Energy dispersive X-ray diffraction (EDXRD) combined with hybrid discriminant analysis (HDA) has been utilized for classifying the liquid materials for the first time. The XRD spectra of 37 kinds of liquid contrabands and daily supplies were obtained using an EDXRD test bed facility. The unique spectra of different samples reveal XRD's capability to distinguish liquid contrabands from daily supplies. In order to create a system to detect liquid contrabands, the diffraction spectra were subjected to HDA which is the combination of principal components analysis (PCA) and linear discriminant analysis (LDA). Experiments based on the leave-one-out method demonstrate that HDA is a practical method with higher classification accuracy and lower noise sensitivity than the other methods in this application. The study shows the great capability and potential of the combination of XRD and HDA for liquid contrabands classification.

Liquid contrabands classification based on energy dispersive X-ray diffraction and hybrid discriminant analysis

Energy Technology Data Exchange (ETDEWEB)

YangDai, Tianyi [Department of Engineering Physics, Tsinghua University, Beijing 100084 (China); Key Laboratory of Particle & Radiation Imaging (Tsinghua University), Ministry of Education (China); Zhang, Li, E-mail: zhangli@nuctech.com [Department of Engineering Physics, Tsinghua University, Beijing 100084 (China); Key Laboratory of Particle & Radiation Imaging (Tsinghua University), Ministry of Education (China)

2016-02-01

Energy dispersive X-ray diffraction (EDXRD) combined with hybrid discriminant analysis (HDA) has been utilized for classifying the liquid materials for the first time. The XRD spectra of 37 kinds of liquid contrabands and daily supplies were obtained using an EDXRD test bed facility. The unique spectra of different samples reveal XRD's capability to distinguish liquid contrabands from daily supplies. In order to create a system to detect liquid contrabands, the diffraction spectra were subjected to HDA which is the combination of principal components analysis (PCA) and linear discriminant analysis (LDA). Experiments based on the leave-one-out method demonstrate that HDA is a practical method with higher classification accuracy and lower noise sensitivity than the other methods in this application. The study shows the great capability and potential of the combination of XRD and HDA for liquid contrabands classification.

Liquid contrabands classification based on energy dispersive X-ray diffraction and hybrid discriminant analysis

Science.gov (United States)

YangDai, Tianyi; Zhang, Li

2016-02-01

Energy dispersive X-ray diffraction (EDXRD) combined with hybrid discriminant analysis (HDA) has been utilized for classifying the liquid materials for the first time. The XRD spectra of 37 kinds of liquid contrabands and daily supplies were obtained using an EDXRD test bed facility. The unique spectra of different samples reveal XRD's capability to distinguish liquid contrabands from daily supplies. In order to create a system to detect liquid contrabands, the diffraction spectra were subjected to HDA which is the combination of principal components analysis (PCA) and linear discriminant analysis (LDA). Experiments based on the leave-one-out method demonstrate that HDA is a practical method with higher classification accuracy and lower noise sensitivity than the other methods in this application. The study shows the great capability and potential of the combination of XRD and HDA for liquid contrabands classification.

Hybrid MF and membrane bioreactor process applied towards water and indigo reuse from denim textile wastewater.

Science.gov (United States)

Couto, Carolina Fonseca; Marques, Larissa Silva; Balmant, Janine; de Oliveira Maia, Andreza Penido; Moravia, Wagner Guadagnin; Santos Amaral, Miriam Cristina

2018-03-01

This work investigates the application of a microfiltration (MF)-membrane bioreactor (MBR) hybrid process for textile dyeing process wastewater reclamation. The indigo blue dye was efficiently retained by the MF membrane (100%), which allows its recovery from the concentrate stream. MF promotes 100% of colour removal, and reduces the chemical oxygen demand (COD) and conductivity by about 65% and 25%, respectively, and improves the wastewater biodegradability. MF flux decline was mostly attributed to concentration polarization and the chemical cleaning was efficient enough to recover initial hydraulic resistance. The MBR provides to be a stable process maintaining its COD and ammonia removal efficiency (73% and 100%, respectively) mostly constant throughout and producing a permeate that meets the reuse criteria for some industry activities, such as washing-off and equipment washdown. The use of an MF or ultrafiltration (UF) membrane in the MBR does not impact the MBR performance in terms of COD removal. Although the membrane of MBR-UF shows permeability lower than MBR-MF membrane, the UF membrane contributes to a more stable operation in terms of permeability.

MEMBRANOUS FLOWS IN GAS-LIQUID COLLECTORS-REGENERATORS OF SOLAR ABSORPTIVE SYSTEMS FEATURES

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Doroshenko А.V.

2009-12-01

Full Text Available Article is devoted to the creation of new generation of solar collectors of the gas-liquid type, intended for use in alternative refrigerating and conditioning systems of drying-evaporating type with direct solar regeneration of absorbent. Special attention is given to the study of membranous flows features on inclined surfaces, including questions of such flows stability.

Effect of UV on De-NOx performance and microbial community of a hybrid catalytic membrane biofilm reactor

Science.gov (United States)

Chen, Zhouyang; Huang, Zhensha; He, Yiming; Xiao, Xiaoliang; Wei, Zaishan

2018-02-01

The hybrid membrane catalytic biofilm reactor provides a new way of flue gas denitration. However, the effects of UV on denitrification performance, microbial community and microbial nitrogen metabolism are still unknown. In this study, the effects of UV on deNO x performance, nitrification and denitrification, microbial community and microbial nitrogen metabolism of a bench scale N-TiO2/PSF hybrid catalytic membrane biofilm reactor (HCMBR) were evaluated. The change from nature light to UV in the HCMBR leads to the fall of NO removal efficiency of HCMBR from 92.8% to 81.8%. UV affected the microbial community structure, but did not change microbial nitrogen metabolism, as shown by metagenomics sequencing method. Some dominant phyla, such as Gammaproteobacteria, Bacteroidetes, Firmicutes, Actinobacteria, and Alphaproteobacteria, increased in abundance, whereas others, such as Proteobacteria and Betaproteobacteria, decreased. There were nitrification, denitrification, nitrogen fixation, and organic nitrogen metabolism in the HCMBR.

Extraction of Lead through Supported Liquid Membrane Using Triethanolamine/Cyclohexanone Carrier and Na2SO4 strippant

Directory of Open Access Journals (Sweden)

Gill R.

2013-04-01

Full Text Available Supported liquid membranes (SLM have proved to be effective not only for removing but also for recovery of heavy metals from waste water. This work includes the study of separation and transport of Pb+2 ions through liquid membrane based on triethanolamine (TEA in cyclohexanone supported in microporous polypropylene films. Therefore, this study aims to optimize the conditions for moving the Pb+2 ions against the concentration gradient, characterize the membrane by flux measurements, for their use in various industrial plants design to recover these ions. The effect of lead ion concentration, HNO3 in feed and TEA concentration in membrane has been studied. Optimized condition of transport of this metal ion is 1.0 M acid concentration in the feed phase and 0.1M Na2SO4 as the strippant when TEA concentration is 5.25 mol/dm3 in the membrane, as the rationale of this study is to optimize the condition for the movement of lead ions from feed phase to strip phase and to recover metal ions from any industrial effluent and finally to characterize the membrane by determining the mobility and permeability of the complexed heavy metal ion to extract their respective metal ions.

Separation of cadmium and lead from wastewater using supported liquid membrane integrated with in-situ electrodeposition

International Nuclear Information System (INIS)

Bhatluri, Kamal Kumar; Manna, Mriganka Sekhar; Ghoshal, Aloke Kumar; Saha, Prabirkumar

2017-01-01

A novel process for separation of heavy metals from liquid wastes and/or industrial effluents has been developed as described in this paper wherein the technique of supported liquid membrane based extraction and stripping of heavy metals has been augmented with electroplating inside the stripping chamber of SLM. Wastewater, infested with cadmium and lead, has been subject of research in this work. The said process is employed in transporting the heavy metals from the polluted source phase (wastewater) to the sink (or strip) phase while simultaneously depositing the heavy metals in-situ on the electrode placed inside the strip phase, and thereby the strip phase is remained ever-unsaturated. This arrangement yields high gradient of chemical potential across the liquid membrane and thereby facilitates enhanced and faster recovery of said heavy metals and also yields value added component, viz. electroplated items, for suitable end use.

Performance of Hollow Fiber Membrane Gas-Liquid Contactors to Absorb CO2 Using Diethanolamine (Dea as a Solvent

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Sutrasno Kartohardjono

2010-10-01

Full Text Available This study uses DEA solution to absorb CO2 from the gas flow through the hollow fiber membrane contactors. This study aims to evaluate the performance of hollow fiber membrane contactors to absorb CO2 gas using DEA solution as solvent through mass transfer and hydrodynamics studies. The use of DEA solution is to reduce the mass transfer resistance in the liquid phase, and on the other side, the large contact area of the membrane surface can cover the disadvantage of membrane contactors; additional mass transfer resistance in the membrane phase. During experiments, CO2 feed flows through the fiber lumens, while the 0.01 M DEA solution flows in the shell side of membrane contactors. Experimental results show that the mass transfer coefficients and fluxes of CO2 increase with an increase in both water and DEA solution flow rates. Increasing the amount of fibers in the contactors will decrease the mass transfer and fluxes at the same DEA solution flow rate. Mass transfer coefficients and CO2 fluxes using DEA solution can achieve 28,000 and 7.6 million times greater than using water as solvent, respectively. Hydrodynamics studies show that the liquid pressure drops in the contactors increase with increasing liquid flow rate and number of fibers in the contactors. The friction between water and the fibers in the contactor was more pronounced at lower velocities, and therefore, the value of the friction factor is also higher at lower velocities.

Performance study of a heat pump driven and hollow fiber membrane-based two-stage liquid desiccant air dehumidification system

International Nuclear Information System (INIS)

Zhang, Ning; Yin, Shao-You; Zhang, Li-Zhi

2016-01-01

Graphical abstract: A heat pump driven, hollow fiber membrane-based two-stage liquid desiccant air dehumidification system. - Highlights: • A two-stage hollow fiber membrane based air dehumidification is proposed. • It is heat pump driven liquid desiccant system. • Performance is improved 20% upon single stage system. • The optimal first to second stage dehumidification area ratio is 1.4. - Abstract: A novel compression heat pump driven and hollow fiber membrane-based two-stage liquid desiccant air dehumidification system is presented. The liquid desiccant droplets are prevented from crossing over into the process air by the semi-permeable membranes. The isoenthalpic processes are changed to quasi-isothermal processes by the two-stage dehumidification processes. The system is set up and a model is proposed for simulation. Heat and mass capacities in the system, including the membrane modules, the condenser, the evaporator and the heat exchangers are modeled in detail. The model is also validated experimentally. Compared with a single-stage dehumidification system, the two-stage system has a lower solution concentration exiting from the dehumidifier and a lower condensing temperature. Thus, a better thermodynamic system performance is realized and the COP can be increased by about 20% under the typical hot and humid conditions in Southern China. The allocations of heat and mass transfer areas in the system are also investigated. It is found that the optimal regeneration to dehumidification area ratio is 1.33. The optimal first to second stage dehumidification area ratio is 1.4; and the optimal first to second stage regeneration area ratio is 1.286.

Rate and mechanism of facilitated americium(III) transport through a supported liquid membrane containing a bifunctional organophosphorus mobile carrier

International Nuclear Information System (INIS)

Danesi, P.R.; Horwitz, E.P.; Rickert, P.G.

1983-01-01

The facilitated transport of Am(III) from aqueous nitrate solutions to formic acid aqueous solutions through a supported liquid membrane (SLM) is described. The supported liquid membrane consists of a solution of a new (carbamoylmethyl)phosphine oxide in diethylbenzene (DEB) absorbed into a 48 μm thick microporous polypropylene film. The transport mechanism consists of a diffusion process through an aqueous diffusion film, a fast interfacial chemical reaction, and diffusion through the membrane itself. Equations describing the rate of transport are derived. They correlate the membrane permeability coefficient to diffusional parameters and to the chemical composition of the system. Different rate-controlling processes are shown to control the membrane permeability when the composition of the system is varied and as long as the transport occurs. The experimental data are quantitatively explained with the derived equations. The diffusion coefficient of the permeating species and the equilibrium constant of the fast interfacial reactions are evaluated. 13 figures, 1 table

Evaluation of nanofiltration membranes for treatment of liquid radioactive waste

International Nuclear Information System (INIS)

Oliveira, Elizabeth Eugenio de Mello

2013-01-01

The physicochemical behavior of two nanofiltration membranes for treatment of a low-level radioactive liquid waste (carbonated water) was investigated through static, dynamic and concentration tests. This waste was produced during conversion of uranium hexafluoride (UF 6 ) to uranium dioxide (UO 2 ) in the cycle of nuclear fuel. This waste contains about 7.0 mg L -1 of uranium and cannot be discarded to the environment without an adequate treatment. In static tests membrane samples were immersed in the waste for 24 to 5000 h. Their transport properties (hydraulic permeability, permeate flux, sulfate and chloride ions rejection) were evaluated before and after immersion in the waste using a permeation flux front system under 0.5 MPa. The selective layer (polyamide) was characterized by zeta potential, contact angle, scanning electron microscopy for field emission, atomic force microscopy, infrared spectroscopy, x-ray fluorescence and thermogravimetric analysis before and after static tests. In dynamic tests the waste was permeated under 0.5 MPa, and the membranes showed rejection to uranium above 85% were obtained. The short-term static tests (24-72 h) showed that the selective layer and surface charge of the membranes were not chemical changed, according infrared spectra data. After 5000 h a coating layer was released from the membranes, poly(vinyl alcohol), PVA. After this loss the rejection for uranium decreased. Permeation and concentration of the waste were carried out in permeation flux tangential system under 1.5 MPa. The rejection of uranium was around 90% for permeation tests. In concentration tests the permeated was collected continuously until about 80% reduction of the feed volume. The rejection of uranium was of the 97%. The nanofiltration membranes tested were efficient to concentrate the uranium from the waste. (author)

Technetium-99m extraction and transport across tri-n-octylamine-xylene based supported liquid membranes

International Nuclear Information System (INIS)

Ashraf Chaudry, M.; Ahmad, B.

1996-01-01

The nuclear properties of 99m Tc radionuclide are ideal for organ imaging. Study of the technetium transport across supported liquid membranes has been performed to get data for its separation from other elements. Tri-n-octylamine diluted in xylene was used to constitute the liquid membranes, supported in polypropylene microporous films. Stripping on the product solution side was performed with dilute NaOH solutions. The effect of sulphuric acid, nitric acid and hydrochloric acid in the feed on transport of 99m Tc as TcO 4 - ions has been studied. The permeability of the given ions determined from kinetic activity data has been found to be in the order of PH 2 SO 4 >PHCl>PHNO 3 . The flux values have been calculated based on this permeability data. The increase in carrier concentration has shown an increase in flux and permeability values to a given optimum concentration. The increase in temperature has been found to reduce the transport of Tc ions. The optimum conditions for transport of 99m Tc for the given acid concentration have been determined. Mechanism of Tc ion transport has also been provided based on chemical reactions involved at the membrane interfaces and uptake of Tc ions by the membrane. MoO 4 2- ions do not permeate through membrane under optimum conditions of transport for TcO 4 2 - ions from H 2 SO 4 solution. (author). 12 refs., 20 figs., 1 tab

Metal ion separations using reactive membranes

International Nuclear Information System (INIS)

Way, J.D.

1993-01-01

A membrane is a barrier between two phases. If one component of a mixture moves through the membrane faster than another mixture component, a separation can be accomplished. Membranes are used commercially for many applications including gas separations, water purification, particle filtration, and macromolecule separations (Abelson). There are two points to note concerning this definition. First, a membrane is defined based on its function, not the material used to make the membrane. Secondly, a membrane separation is a rate process. The separation is accomplished by a driving force, not by equilibrium between phases. Liquids that are immiscible with the feed and product streams can also be used as membrane materials. Different solutes will have different solubilities and diffusion coefficients in a liquid. The product of the diffusivity and the solubility is known as the permeability coefficient, which is proportional to the solute flux. Differences in permeability coefficient will produce a separation between solutes at constant driving force. Because the diffusion coefficients in liquids are typically orders of magnitude higher than in polymers, a larger flux can be obtained. Further enhancements can be accomplished by adding a nonvolatile complexation agent to the liquid membrane. One can then have either coupled or facilitated transport of metal ions through a liquid membrane. The author describes two implementations of this concept, one involving a liquid membrane supported on a microporous membrane, and the other an emulsion liquid membrane, where separation occurs to internal receiving phases. Applications and costing studies for this technology are reviewed, and a brief summary of some of the problems with liquid membranes is presented

Extraction of rare earth elements with organophosphorus extractants as carriers in supported liquid membranes

International Nuclear Information System (INIS)

Kopunec, R.; Benitez, J.C.

1991-01-01

The membrane extraction of Y, Ce, Eu, Tm and their binary mixtures Ce-Y, Ce-Eu, Ce-Tm with supported liquid membranes containing TBP and HDEHP as carriers in decane-dodecane hydrocarbon solvent, has been studied. Upon extraction with TBP aqueous nitrate solutions of rare earth elements (REE) were used as feed phase. In some cases they also contained EDTA or DCTA. In most cases, the receiving phase was an aqueous solution of EDTA. Extraction with HDEHP was performed from nitrate and chloride solutions and the receiving phase was the corresponding dilute acid. Pertraction of an element through a membrane was studied as a function of time and of initial composition of phases. The results are presented in the following forms: flux of metal through membrane, coefficients of permeability, separation factors and effective diffusion coefficients. (author) 24 refs.; 8 figs.; 3 tabs

Evaluation of energy-distribution of a hybrid microbial fuel cell-membrane bioreactor (MFC-MBR) for cost-effective wastewater treatment.

Science.gov (United States)

Wang, Jie; Bi, Fanghua; Ngo, Huu-Hao; Guo, Wenshan; Jia, Hui; Zhang, Hongwei; Zhang, Xinbo

2016-01-01

A low-cost hybrid system integrating a membrane-less microbial fuel cell (MFC) with an anoxic/oxic membrane bioreactor (MBR) was studied for fouling mitigation. The appended electric field in the MBR was supplied by the MFC with continuous flow. Supernatant from an anaerobic reactor with low dissolved oxygen was used as feed to the MFC in order to enhance its performance compared with that fed with synthetic wastewater. The voltage output of MFC maintained at 0.52±0.02V with 1000Ω resister. The electric field intensity could reach to 0.114Vcm(-1). Compared with the conventional MBR (CMBR), the contents rather than the components of foulants on the cake layer of fouled MFC-MBR system was significantly reduced. Although only 0.5% of the feed COD was translated into electricity and applied to MBR, the hybrid system showed great feasibility without additional consumption but extracting energy from waste water and significantly enhancing the membrane filterability. Copyright © 2015 Elsevier Ltd. All rights reserved.

Study of the extraction and the purification of americium and trivalent actinides contained in effluents with supported liquid membranes

International Nuclear Information System (INIS)

Guillou, P.

1990-12-01

The supported liquid membrane technique is studied and developed for americium recovery from uranium or plutonium matrices and decontamination of liquid radioactive wastes. First tests on uranium-nickel solutions with a flat membrane showed the easiness of the operation and the efficiency of the process. Acid-resistant (10 N), interchangeable elements with hollow fibers, are developed and also a computerized automatic device. The different tests on americium solutions demonstrate the feasibility and the reliability of the system. Influence of various parameters on transfer kinetics is investigated

Hybrid membrane contactor system for creating semi-breathing air

Science.gov (United States)

Timofeev, D. V.

2012-02-01

Typically, the equipment to create an artificial climate does not involve changing the composition of the respiratory air. In particular in medical institutions assumes the existence of plant of artificial climate and disinfection in operating rooms and intensive care wards. The use of a hybrid membrane-absorption systems for the generation of artificial atmospheres are improving the respiratory system, blood is enriched or depleted of various gases, resulting in increased stamina, there is a better, faster or slower metabolism, improves concentration and memory. Application of the system contributes to easy and rapid recovery after the operation. By adding a special component, with drug activity, air ionization, and adjust its composition, you can create a special, more favorable for patients with the atmosphere. These factors allow for the treatment and rehabilitation of patients and reduce mortality of heavy patients.

Thin-film Nanofibrous Composite Membranes Containing Cellulose or Chitin Barrier Layers Fabricated by Ionic Liquids

Energy Technology Data Exchange (ETDEWEB)

H Ma; B Hsiao; B Chu

2011-12-31

The barrier layer of high-flux ultrafiltration (UF) thin-film nanofibrous composite (TFNC) membranes for purification of wastewater (e.g., bilge water) have been prepared by using cellulose, chitin, and a cellulose-chitin blend, regenerated from an ionic liquid. The structures and properties of regenerated cellulose, chitin, and a cellulose-chitin blend were analyzed with thermogravimetric analysis (TGA) and wide-angle X-ray diffraction (WAXD). The surface morphology, pore size and pore size distribution of TFNC membranes were determined by SEM images and molecular weight cut-off (MWCO) methods. An oil/water emulsion, a model of bilge water, was used as the feed solution, and the permeation flux and rejection ratio of the membranes were investigated. TFNC membranes based on the cellulose-chitin blend exhibited 10 times higher permeation flux when compared with a commercial UF membrane (PAN10, Sepro) with a similar rejection ratio after filtration over a time period of up to 100 h, implying the practical feasibility of such membranes for UF applications.

Mathematical Modelling of Nitrate Removal from Water Using a Submerged Membrane Adsorption Hybrid System with Four Adsorbents

Directory of Open Access Journals (Sweden)

Mahatheva Kalaruban

2018-01-01

Full Text Available Excessive concentrations of nitrate in ground water are known to cause human health hazards. A submerged membrane adsorption hybrid system that includes a microfilter membrane and four different adsorbents (Dowex 21K XLT ion exchange resin (Dowex, Fe-coated Dowex, amine-grafted (AG corn cob and AG coconut copra operated at four different fluxes was used to continuously remove nitrate. The experimental data obtained in this study was simulated mathematically with a homogeneous surface diffusion model that incorporated membrane packing density and membrane correlation coefficient, and applied the concept of continuous flow stirred tank reactor. The model fit with experimental data was good. The surface diffusion coefficient was constant for all adsorbents and for all fluxes. The mass transfer coefficient increased with flux for all adsorbents and generally increased with the adsorption capacity of the adsorbents.

Development of robust fluorinated TiO2/PVDF composite hollow fiber membrane for CO2 capture in gas-liquid membrane contactor

Science.gov (United States)

Lin, Yuqing; Xu, Yilin; Loh, Chun Heng; Wang, Rong

2018-04-01

Gas-liquid membrane contactor (GLMC) is a promising method to attain high efficiency for CO2 capture from flue gas, biogas and natural gas. However, membranes used in GLMC are prone to pore wetting due to insufficient hydrophobicity and low chemical resistance, resulting in significant increase in mass transfer resistance. To mitigate this issue, inorganic-organic fluorinated titania/polyvinylidene fluoride (fTiO2/PVDF) composite hollow fiber (HF) membranes was prepared via facile in-situ vapor induced hydrolyzation method, followed by hydrophobic modification. The proposed composite membranes were expected to couple the superb chemical stability of inorganic and high permeability/low cost of organic materials. The continuous fTiO2 layer deposited on top of PVDF substrate was found to possess a tighter microstructure and better hydrophobicity, which effectively prevented the membrane from wetting and lead to a high CO2 absorption flux (12.7 × 10-3 mol m-2 s-1). In a stability test with 21-day operation of GLMC using 1M monoethanolamine (MEA) as the absorbent, the fTiO2/PVDF membrane remained to be intact with a CO2 absorption flux decline of ∼16%, while the pristine PVDF membrane suffered from a flux decline of ∼80% due to membrane damage. Overall, this work provides an insight into the preparation of high-quality inorganic/organic composite HF membranes for CO2 capture in GLMC application.

Synthesis and electrochemical characterization of hybrid membrane Nafion-SiO2 for application as polymer electrolyte in PEM fuel cell

International Nuclear Information System (INIS)

Dresch, Mauro Andre

2009-01-01

In this work, the effect of sol-gel synthesis parameters on the preparation and polarization response of Nafion-SiO 2 hybrids as electrolytes for proton exchange membrane fuel cells (PEMFC) operating at high temperatures (130 degree C) was evaluated. The inorganic phase was incorporated in a Nafion matrix with the following purposes: to improve the Nafion water uptake at high temperatures (> 100 degree C); to increase the mechanical strength of Nafion and; to accelerate the electrode reactions. The hybrids were prepared by an in-situ incorporation of silica into commercial Nafion membranes using an acid-catalyzed sol-gel route. The effects of synthesis parameters, such as catalyst concentration, sol-gel solvent, temperature and time of both hydrolysis and condensation reactions, and silicon precursor concentration (Tetraethyl orthosilicate - TEOS), were evaluated as a function on the incorporation degree and polarization response. Nafion-SiO 2 hybrids were characterized by gravimetry, thermogravimetric analysis (TGA), scanning electron microscopy and X-ray dispersive energy (SEM-EDS), electrochemical impedance spectroscopy (EIS), and X-ray small angle scattering (SAXS). The hybrids were tested as electrolyte in single H 2 /O 2 fuel cells in the temperature range of 80 - 130 degree C and at 130 degree C and reduced relative humidity (75% and 50%). Summarily, the hybrid performance showed to be strongly dependent on the synthesis parameters, mainly, the type of alcohol and the TEOS concentration. (author)

Hybrid Graphene-Polyoxometalates Nanofluids as Liquid Electrodes for Dual Energy Storage in Novel Flow Cells.

Science.gov (United States)

Dubal, Deepak P; Rueda-Garcia, Daniel; Marchante, Carlos; Benages, Raul; Gomez-Romero, Pedro

2018-02-22

Solid Hybrid materials abound. But flowing versions of them are new actors in the materials science landscape and in particular for energy applications. This paper presents a new way to deliver nanostructured hybrid materials for energy storage, namely, in the form of nanofluids. We present here the first example of a hybrid electroactive nanofluid (HENFs) combining capacitive and faradaic energy storage mechanisms in a single fluid material. This liquid electrode is composed of reduced graphene oxide and polyoxometalates (rGO-POMs) forming a stable nanocomposite for electrochemical energy storage in novel Nanofluid Flow Cells. Two graphene based hybrid materials (rGO-phosphomolybdate, rGO-PMo 12 and rGO-phosphotungstate, rGO-PW 12 ) were synthesized and dispersed with the aid of a surfactant in 1 M H 2 SO 4 aqueous electrolyte to yield highly stable hybrid electroactive nanofluids (HENFs) of low viscosity which were tested in a home-made flow cell under static and continuous flowing conditions. Remarkably, even low concentration rGO-POMs HENFs (0.025 wt%) exhibited high specific capacitances of 273 F/g(rGO-PW 12 ) and 305 F/g(rGO-PMo 12 ) with high specific energy and specific power. Moreover, rGO-POM HENFs show excellent cycling stability (∼95 %) as well as Coulombic efficiency (∼77-79 %) after 2000 cycles. Thus, rGO-POM HENFs effectively behave as real liquid electrodes with excellent properties, demonstrating the possible future application of HENFs for dual energy storage in a new generation of Nanofluid Flow Cells. © 2018 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Sample clean-up, enrichment and determination of s-triazine herbicides from southern ethiopian lakes supported using liquid membrane extraction

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Jan Åke Jönsson

2000-06-01

Full Text Available The liquid membrane extraction method has been employed for selectively extracting trace quantities of s-triazine herbicides in environmental waters collected from lakes Awassa, Chamo and Abbya, located in close proximity to the agricultural farms in Southern Ethiopia. In liquid membrane extraction, the uncharged triazine compounds from the flowing donor solution diffuse through a porous poly(tetrafluoroethylene (PTFE membrane, containing a water immiscible organic solvent. The s-triazine molecules are then irreversibly trapped in the stagnant acidic acceptor phase since they become protonated. Using both di-n-hexylether and n-undecane membrane solvents, s-traizine herbicides were extracted and low detection limits of about 1 ng/L have been obtained by extraction of three liters of sample solution spiked with 0.1 g/L of each triazine. Residues of atrazine and terbutryn ranging in concentration from 0.02 to 0.05 g/L have been successfully determined.

Nuclide separation modeling through reverse osmosis membranes in radioactive liquid waste

OpenAIRE

Lee, Byung-Sik

2015-01-01

The aim of this work is to investigate the transport mechanism of radioactive nuclides through the reverse osmosis (RO) membrane and to estimate its effectiveness for nuclide separation from radioactive liquid waste. An analytical model is developed to simulate the RO separation, and a series of experiments are set up to confirm its estimated separation behavior. The model is based on the extended Nernst–Plank equation, which handles the convective flux, diffusive flux, and electromigration f...

Performance Evaluation of Bulk Liquid Membrane Technique on p-Nitrophenol Removal from Aqueous Solution

Directory of Open Access Journals (Sweden)

K. Pourkhanali

2018-03-01

Full Text Available The transport of p-nitrophenol (PNP through a bulk liquid membrane (BLM was investigated to evaluate the effect of different experimental conditions on PNP partitioning behavior. The influence of solvent type, different salts in feed phase, the feed phase pH and PNP concentration in feed phase on transport efficiency of PNP through the BLM were studied. The results indicated that the highest removal efficiency of PNP was observed for 80 % xylene + 20 % toluene as liquid membrane, Na2SO4 as salt in feed phase, in the acidic feed phase and in 150 min. The effect of initial concentration of PNP on the efficiency of the separation PNP showed that the increase in initial concentration up to 350 ppm had positive effect, and more than 350 ppm had negative effect on the PNP removal behavior. Also, pertraction in BLM systems were described by a kinetic model of two consecutive irreversible first order chemical reactions.

Hybrid glasses from strong and fragile metal-organic framework liquids.

Science.gov (United States)

Bennett, Thomas D; Tan, Jin-Chong; Yue, Yuanzheng; Baxter, Emma; Ducati, Caterina; Terrill, Nick J; Yeung, Hamish H-M; Zhou, Zhongfu; Chen, Wenlin; Henke, Sebastian; Cheetham, Anthony K; Greaves, G Neville

2015-08-28

Hybrid glasses connect the emerging field of metal-organic frameworks (MOFs) with the glass formation, amorphization and melting processes of these chemically versatile systems. Though inorganic zeolites collapse around the glass transition and melt at higher temperatures, the relationship between amorphization and melting has so far not been investigated. Here we show how heating MOFs of zeolitic topology first results in a low density 'perfect' glass, similar to those formed in ice, silicon and disaccharides. This order-order transition leads to a super-strong liquid of low fragility that dynamically controls collapse, before a subsequent order-disorder transition, which creates a more fragile high-density liquid. After crystallization to a dense phase, which can be remelted, subsequent quenching results in a bulk glass, virtually identical to the high-density phase. We provide evidence that the wide-ranging melting temperatures of zeolitic MOFs are related to their network topologies and opens up the possibility of 'melt-casting' MOF glasses.

Synthesis and characterization of ionic liquid (EMImBF{sub 4})/Li{sup +} - chitosan membranes for ion battery

Energy Technology Data Exchange (ETDEWEB)

Pasaribu, Marvin H., E-mail: marvin-shady88@yahoo.com; Arcana, I Made, E-mail: arcana@chem.itb.ac.id; Wahyuningrum, Deana, E-mail: deana@chem.itb.ac.id [Department of Chemistry, Faculty of Mathematics and Natural Sciences, InstitutTeknologi Bandung, Jl. Ganesha No. 10, Bandung 40132 (Indonesia)

2015-09-30

Lithium ion battery has been currently developed and produced because it has a longer life time, high energycapacity, and the efficient use of lithium ion battery that is suitable for storing electrical energy. However, this battery has some drawbacks such as use liquid electrolytes that are prone to leakage and flammability during the battery charging process in high temperature. In this study, an ionic liquid 1-ethyl-3-methylimidazolium tetrafluoroborate (EMImBF4) containing Li{sup +} ions was synthesized and combined with chitosan polymer host as a polymer electrolyte membrane for lithium-ion batteries to solve this problems. This ionic liquid was obtained from the anion metathesis reaction between EMImBr and LiBF4 salt, while EMImBr was synthesized from the reaction between 1-methylimidazole and ethyl bromide utilizing Microwave Assisted Organic Synthesis (MAOS) method. The ionic liquid obtained was characterized by microstructure analysis with using NMR and FTIR spectroscopy. The polymer electrolyte membrane was characterized by analysis functional groups (FTIR), ionic conductivity (EIS), and surface morphology (SEM). The analysis results of ion conductivity by the EIS method showed the increase the ionic conductivity value of membranes from 1.30 × 10{sup −2} S cm{sup −1} for chitosan to 1.30 × 10{sup −2} S cm{sup −1} for chitosan with EMImBF4/Li{sup +}, and this result was supported by analysis the surface morphology (SEM)

A fluidic device for the controlled formation and real-time monitoring of soft membranes self-assembled at liquid interfaces.

Science.gov (United States)

Mendoza-Meinhardt, Arturo; Botto, Lorenzo; Mata, Alvaro

2018-02-13

Membrane materials formed at the interface between two liquids have found applications in a large variety of technologies, from sensors to drug-delivery and catalysis. However, studying the formation of these membranes in real-time presents considerable challenges, owing to the difficulty of prescribing the location and instant of formation of the membrane, the difficulty of observing time-dependent membrane shape and thickness, and the poor reproducibility of results obtained using conventional mixing procedures. Here we report a fluidic device that facilitates characterisation of the time-dependent thickness, morphology and mass transport properties of materials self-assembled at fluid-fluid interfaces. In the proposed device the membrane forms from the controlled coalescence of two liquid menisci in a linear open channel. The linear geometry and controlled mixing of the solutions facilitate real-time visualisation, manipulation and improve reproducibility. Because of its small dimensions, the device can be used in conjunction with standard microscopy methods and reduces the required volumes of potentially expensive reagents. As an example application to tissue engineering, we use the device to characterise interfacial membranes formed by supra-molecular self-assembly of peptide-amphiphiles with either an elastin-like-protein or hyaluronic acid. The device can be adapted to study self-assembling membranes for applications that extend beyond bioengineering.

Selective separation of furfural and hydroxymethylfurfural from an aqueous solution using a supported hydrophobic deep eutectic solvent liquid membrane.

Science.gov (United States)

Dietz, Carin H J T; Kroon, Maaike C; Di Stefano, Michela; van Sint Annaland, Martin; Gallucci, Fausto

2017-12-14

For the first time, 12 different supported deep eutectic solvent (DES) liquid membranes were prepared and characterized. These membranes consist of a polymeric support impregnated with a hydrophobic DES. First, the different membranes were characterized and their stability in water and air was determined. Subsequently, the supported DES liquid membranes were applied for the recovery of furfural (FF) and hydroxymethylfurfural (HMF) from aqueous solutions. The effects of substrate properties (e.g. pore size), DES properties (e.g. viscosity) and concentrations of FF and HMF in the feed phase on the observed diffusivities and permeabilities were assessed. It was found that the addition of DES enhances the transport of FF and HMF through the polymeric membrane support. In particular, the use of the DES consisting of thymol + lidocaine (in the molar ratio 2 : 1) impregnated in a polyethylene support resulted in enhanced transport for both FF and HMF, and is most interesting for (in situ) isolation of FF and HMF from aqueous solutions, e.g. in biorefinery processes.

Liquid-liquid electro-organo-synthetic processes in a carbon nanofibre membrane microreactor: Triple phase boundary effects in the absence of intentionally added electrolyte

International Nuclear Information System (INIS)

Watkins, John D.; Ahn, Sunyhik D.; Taylor, James E.; Bull, Steven D.; Bulman-Page, Philip C.; Marken, Frank

2011-01-01

Graphical abstract: Display Omitted Highlights: → Amphiphilic carbon nanofiber membrane employed in electro-synthesis. → Triple phase boundary process within a carbon membrane. → Electrochemical deuteration in a liquid|liquid micro-reactor system. → Triple phase boundary reaction zone effects in electro-synthesis. - Abstract: An amphiphilic carbon nanofibre membrane electrode (ca. 50 nm fibre diameter, 50-100 μm membrane thickness) is employed as an active working electrode and separator between an aqueous electrolyte phase (with reference and counter electrode) and an immiscible organic acetonitrile phase (containing only the redox active material). Potential control is achieved with a reference and counter electrode located in the aqueous electrolyte phase, but the electrolysis is conducted in the organic acetonitrile phase in the absence of intentionally added supporting electrolyte. For the one-electron oxidation of n-butylferrocene coupled to perchlorate anion transfer from aqueous to organic phase effective electrolysis is demonstrated with an apparent mass transfer coefficient of m = 4 x 10 -5 m s -1 and electrolysis of typically 1 mg n-butylferrocene in a 100 μL volume. For the two-electron reduction of tetraethyl-ethylenetetracarboxylate the apparent mass transfer coefficient m = 4 x 10 -6 m s -1 is lower due to a less extended triple phase boundary reaction zone in the carbon nanofibre membrane. Nevertheless, effective electrolysis of up to 6 mg tetraethyl-ethylenetetracarboxylate in a 100 μL volume is demonstrated. Deuterated products are formed in the presence of D 2 O electrolyte media. The triple phase boundary dominated mechanism and future microreactor design improvements are discussed.

Inhibitory effect of membrane-specific drugs on liquid-holding recovery in U.V.-irradiated E. coli cells

International Nuclear Information System (INIS)

Yonei, S.

1980-01-01

Liquid-holding recovery (LHR), as been shown to be dependent on the polA + -dependent DNA repair pathways. The experiment described attempted to examine whether the membrane-specific drugs, procaine and chlorpromazine, can inhibit the LHR in U.V.-irradiated cells of E. coli B. Results show that cell membranes may influence DNA repair and ultimate survival of E. coli. (author)

Non-uniform binding of single-stranded DNA binding proteins to hybrids of single-stranded DNA and single-walled carbon nanotubes observed by atomic force microscopy in air and in liquid

Energy Technology Data Exchange (ETDEWEB)

Umemura, Kazuo, E-mail: meicun2006@163.com; Ishizaka, Kei; Nii, Daisuke; Izumi, Katsuki

2016-12-01

Highlights: • Conjugates of protein, DNA, and SWNTs were observed by AFM in liquid. • Non-uniform binding of proteins was visualized in liquid. • Thickness of DNA molecules on SWNT surfaces was well characterized in liquid. - Abstract: Using atomic force spectroscopy (AFM), we observed hybrids of single-stranded DNA (ssDNA) and single-walled carbon nanotubes (SWNTs) with or without protein molecules in air and in an aqueous solution. This is the first report of ssDNA–SWNT hybrids with proteins in solution analyzed by AFM. In the absence of protein, the height of the ssDNA–SWNT hybrids was 1.1 ± 0.3 nm and 2.4 ± 0.6 nm in air and liquid, respectively, suggesting that the ssDNA molecules adopted a flexible structure on the SWNT surface. In the presence of single-stranded DNA binding (SSB) proteins, the heights of the hybrids in air and liquid increased to 6.4 ± 3.1 nm and 10.0 ± 4.5 nm, respectively. The AFM images clearly showed binding of the SSB proteins to the ssDNA–SWNT hybrids. The morphology of the SSB–ssDNA–SWNT hybrids was non-uniform, particularly in aqueous solution. The variance of hybrid height was quantitatively estimated by cross-section analysis along the long-axis of each hybrid. The SSB–ssDNA–SWNT hybrids showed much larger variance than the ssDNA–SWNT hybrids.