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Sample records for bulk liquid membrane

  1. Analytical Applications of Transport Through Bulk Liquid Membranes.

    Science.gov (United States)

    Diaconu, Ioana; Ruse, Elena; Aboul-Enein, Hassan Y; Bunaciu, Andrei A

    2016-07-03

    This review discusses the results of research in the use of bulk liquid membranes in separation processes and preconcentration for analytical purposes. It includes some theoretical aspects, definitions, types of liquid membranes, and transport mechanism, as well as advantages of using liquid membranes in laboratory studies. These concepts are necessary to understand fundamental principles of liquid membrane transport. Due to the multiple advantages of liquid membranes several studies present analytical applications of the transport through liquid membranes in separation or preconcentration processes of metallic cations and some organic compounds, such as phenol and phenolic derivatives, organic acids, amino acids, carbohydrates, and drugs. This review presents coupled techniques such as separation through the liquid membrane coupled with flow injection analysis.

  2. Dynamics of a Room Temperature Ionic Liquid in Supported Ionic Liquid Membranes vs the Bulk Liquid: 2D IR and Polarized IR Pump-Probe Experiments.

    Science.gov (United States)

    Shin, Jae Yoon; Yamada, Steven A; Fayer, Michael D

    2017-01-11

    Supported ionic liquid membranes (SILMs) are membranes that have ionic liquids impregnated in their pores. SILMs have been proposed for advanced carbon capture materials. Two-dimensional infrared (2D IR) and polarization selective IR pump-probe (PSPP) techniques were used to investigate the dynamics of reorientation and spectral diffusion of the linear triatomic anion, SeCN(-), in poly(ether sulfone) (PES) membranes and room-temperature ionic liquid (RTIL), 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EmimNTf2). The dynamics in the bulk EmimNTf2 were compared to its dynamics in the SILM samples. Two PES membranes, PES200 and PES30, have pores with average sizes, ∼300 nm and ∼100 nm, respectively. Despite the relatively large pore sizes, the measurements reveal that the reorientation of SeCN(-) and the RTIL structural fluctuations are substantially slower in the SILMs than in the bulk liquid. The complete orientational randomization, slows from 136 ps in the bulk to 513 ps in the PES30. 2D IR measurements yield three time scales for structural spectral diffusion (SSD), that is, the time evolution of the liquid structure. The slowest decay constant increases from 140 ps in the bulk to 504 ps in the PES200 and increases further to 1660 ps in the PES30. The results suggest that changes at the interface propagate out and influence the RTIL structural dynamics even more than a hundred nanometers from the polymer surface. The differences between the IL dynamics in the bulk and in the membranes suggest that studies of bulk RTIL properties may be poor guides to their use in SILMs in carbon capture applications.

  3. Separation study of some heavy metal cations through a bulk liquid membrane containing 1,13-bis(8-quinolyl-1,4,7,10,13-pentaoxatridecane

    Directory of Open Access Journals (Sweden)

    Gholam Hossein Rounaghi

    2016-09-01

    Full Text Available Competitive permeation of seven metal cations from an aqueous source phase containing equimolar concentrations of Co2+, Fe3+, Cd2+, Cu2+, Zn2+, Ag+ and Pb2+ metal ions at pH 5 into an aqueous receiving phase at pH 3 through an organic phase facilitated by 1,13-bis(8-quinolyl-1,4,7,10,13-pentaoxatridecane (Kryptofix5 as a carrier was studied as bulk liquid membrane transport. The obtained results show that the carrier is highly selective for Ag+ cation and under the employed experimental conditions, it transports only this metal cation among the seven studied metal cations. The effects of various organic solvents on cation transport rates have been demonstrated. Among the organic solvents involving nitrobenzene (NB, chloroform (CHCl3, dichloromethane (DCM and 1,2-dichloroethane (1,2-DCE which were used as liquid membrane, the most transport rate was obtained for silver (I cation in DCM. The sequence of transport rate for this cation in organic solvents was: DCM > CHCl3 > 1,2-DCE > NB. The competitive transport of these seven metal cations was also studied in CHCl3–NB and CHCl3–DCM binary solvents as membrane phase. The results show that the transport rate of Ag+ cation is sensitive to the solvent composition and a non-linear relationship was observed between the transport rate of Ag+ and the composition of these binary mixed non-aqueous solvents. The influence of the stearic acid, palmitic acid and oleic acid as surfactant in the membrane phase on the transport of the metal cations was also investigated.

  4. Kinetic Study of Copper(II Simultaneous Extraction/Stripping from Aqueous Solutions by Bulk Liquid Membranes Using Coupled Transport Mechanisms

    Directory of Open Access Journals (Sweden)

    Loreto León

    2016-09-01

    Full Text Available Heavy metals removal/recovery from industrial wastewater has become a prime concern for both economic and environmental reasons. This paper describes a comparative kinetic study of the removal/recovery of copper(II from aqueous solutions by bulk liquid membrane using two types of coupled facilitated transport mechanisms and three carriers of different chemical nature: benzoylacetone, 8-hydroxyquinoline, and tri-n-octylamine. The results are analyzed by means of a kinetic model involving two consecutive irreversible first-order reactions (extraction and stripping. Rate constants and efficiencies of the extraction (k1, EE and the stripping (k2, SE reactions, and maximum fluxes through the membrane, were determined for the three carriers to compare their efficiency in the Cu(II removal/recovery process. Counter-facilitated transport mechanism using benzoylacetone as carrier and protons as counterions led to higher maximum flux and higher extraction and stripping efficiencies due to the higher values of both the extraction and the stripping rate constants. Acceptable linear relationships between EE and k1, and between SE and k2, were found.

  5. Parallel artificial liquid membrane extraction

    DEFF Research Database (Denmark)

    Gjelstad, Astrid; Rasmussen, Knut Einar; Parmer, Marthe Petrine

    2013-01-01

    This paper reports development of a new approach towards analytical liquid-liquid-liquid membrane extraction termed parallel artificial liquid membrane extraction. A donor plate and acceptor plate create a sandwich, in which each sample (human plasma) and acceptor solution is separated by an arti...... by an artificial liquid membrane. Parallel artificial liquid membrane extraction is a modification of hollow-fiber liquid-phase microextraction, where the hollow fibers are replaced by flat membranes in a 96-well plate format....

  6. Behavior of hydrophobic ionic liquids as liquid membranes on phenol removal: Experimental study and optimization

    CERN Document Server

    Ng, Y S; Hashim, M A

    2014-01-01

    Room temperature ionic liquids show potential as an alternative to conventional organic membrane solvents mainly due to their properties of low vapor pressure, low volatility and they are often stable. In the present work, the technical feasibilities of room temperature ionic liquids as bulk liquid membranes for phenol removal were investigated experimentally. Three ionic liquids with high hydrophobicity were used and their phenol removal efficiency, membrane stability and membrane loss were studied. Besides that, the effects of several parameters, namely feed phase pH, feed concentration, NaOH concentration and stirring speeds on the performance of best ionic liquid membrane were also evaluated. Lastly, an optimization study on bulk ionic liquid membrane was conducted and the maximum phenol removal efficiency was compared with the organic liquid membranes. The preliminary study shows that high phenol extraction and stripping efficiencies of 96.21% and 98.10%, respectively can be achieved by ionic liquid memb...

  7. Application of the penetration theory for gas - Liquid mass transfer without liquid bulk : Differences with system with a bulk

    NARCIS (Netherlands)

    van Elk, E. P.; Knaap, M. C.; Versteeg, G. F.

    2007-01-01

    Frequently applied micro models for gas-liquid mass transfer all assume the presence of a liquid bulk. However, some systems are characterized by the absence of a liquid bulk, a very thin layer of liquid flows over a solid surface. An example of such a process is absorption in a column equipped with

  8. Negative Effects of Sludge Bulking in Membrane Bio-Reactor

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ying; HUANG Zhi; REN Nanqi; MENG Qingjuan

    2006-01-01

    Sludge bulking property of membrane bio-reactor was investigated in this study through contrast research. When the sludge bulking appeared, the removal efficiency of COD in membrane bio-reactor increased slightly through the function of filamentous bacteria. However, the negative effects of the higher net water-head differential pressures, the high block rate of membrane pore and the great quantity of filamentous bacteria at the external surface presented at the same time. Thus, plenty of methods should be performed to control sludge bulking once it happened in membrane bio-reactor.

  9. Liquid membrane purification of biogas

    Energy Technology Data Exchange (ETDEWEB)

    Majumdar, S.; Guha, A.K.; Lee, Y.T.; Papadopoulos, T.; Khare, S. (Stevens Inst. of Tech., Hoboken, NJ (United States). Dept. of Chemistry and Chemical Engineering)

    1991-03-01

    Conventional gas purification technologies are highly energy intensive. They are not suitable for economic removal of CO{sub 2} from methane obtained in biogas due to the small scale of gas production. Membrane separation techniques on the other hand are ideally suited for low gas production rate applications due to their modular nature. Although liquid membranes possess a high species permeability and selectivity, they have not been used for industrial applications due to the problems of membrane stability, membrane flooding and poor operational flexibility, etc. A new hollow-fiber-contained liquid membrane (HFCLM) technique has been developed recently. This technique overcomes the shortcomings of the traditional immobilized liquid membrane technology. A new technique uses two sets of hydrophobic, microporous hollow fine fibers, packed tightly in a permeator shell. The inter-fiber space is filled with an aqueous liquid acting as the membrane. The feed gas mixture is separated by selective permeation of a species through the liquid from one fiber set to the other. The second fiber set carries a sweep stream, gas or liquid, or simply the permeated gas stream. The objectives (which were met) of the present investigation were as follows. To study the selective removal of CO{sub 2} from a model biogas mixture containing 40% CO{sub 2} (the rest being N{sub 2} or CH{sub 4}) using a HFCLM permeator under various operating modes that include sweep gas, sweep liquid, vacuum and conventional permeation; to develop a mathematical model for each mode of operation; to build a large-scale purification loop and large-scale permeators for model biogas separation and to show stable performance over a period of one month.

  10. Separation of Cu2+, Cd2+ and Cr3+ in a Mixture Solution Using a Novel Carrier Poly(Methyl Thiazoleethyl Eugenoxy Acetate) with BLM (Bulk Liquid Membrane)

    Science.gov (United States)

    Djunaidi, M. C.; Khabibi; Ulumudin, I.

    2017-02-01

    The separation process using a novel carrier polyeugenol has active groups N and S has been done with the technique BLM. Polyeugenol has groups active N and S was synthesized from eugenol which is then polymerized into polyeugenol. This polymeric compounds was then acidified become acidic poly (eugenoksi acetate). After the acid formed, then the synthesis was continued by add 4-methyl-5-tiazoleetanol to form esters poly (methyl thiazole eugenoxy ethyl acetate) (PMTEEA). The result of the synthesis was analyzed by FTIR and 1H NMR. This polyester product synthesis was applied as a carrier for separating metal ions Cu2+, Cd2+ and Cr3+ with variations in feed phase pH = 5 and pH = 7 in the membrane of chloroform using techniques BLM. Receiving phase after 24 hours was analyzed by AAS. In variations of feed pH = 5 ions was obtained 66.21% Cd2+, 28.83% Cu2+ and 10.92% of Cr3+, at pH = 7 was obtained 70.77% Cd2+, 30.14% Cu2+, and 3.72% of Cr3+.

  11. 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.

  12. MECHANISM OF LIQUID MEMBRANES AND APPLICATIONS

    Directory of Open Access Journals (Sweden)

    Filiz Nuran ACAR

    2002-02-01

    Full Text Available It has been considerably studied on the recycling of waste materials in the source besides of wastewater treatment in the last years. It has been important developments on the using of semiconductor membranes in the recycling of toxic materials such as heavy metals, intensifying the environment protection measures especially in the west countries. Wastewater treatment has been achieved with liquid membranes as it has been achieved with polymeric membrane systems such as ultrafiltration, microfiltration, electrodialysis. At the same time, liquid membranes are used for removal of metal ions in hydrometallurgy. Liquid membranes are also used in biotechnology, medical areas and gas separation process.

  13. Polymer liquid membrane for nanofiber fabrication

    Directory of Open Access Journals (Sweden)

    Kong Hai-Yan

    2013-01-01

    Full Text Available This paper finds that a polymer liquid membrane can be effectively used for nanomaterials fabrication using a blowing air and an electronic force. Polyvinyl alcohol solution is used to produce membrane on a rotating ring, which passes through periodically the solution, the membrane is deformed into a bubble by the blowing air under the presence of an electrostatic field. The experimental data show that the receptor distance affects the fiber size greatly.

  14. Diffusion coefficient of an inclusion in a liquid membrane supported by a solvent of arbitrary thickness

    OpenAIRE

    2011-01-01

    The diffusion coefficient of a circular shaped inclusion in a liquid membrane is investigated by taking into account the interaction between membranes and bulk solvents of arbitrary thickness. As illustrative examples, the diffusion coefficients of two types of inclusions - a circular domain composed of fluid with the same viscosity as the host membrane and that of a polymer chain embedded in the membrane are studied.The diffusion coefficients are expressed in terms of the hydrodynamic screen...

  15. Sludge Bulking Property of Membrane Bio-reactor in Albumen Wqastewater Treatment

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    Albumen wastewater was treated by Membrane Bio-reactor. Sludge bulking property of Membrane Bio-Reactor was investigated in this study through contrast research. When the sludge bulking appeared, the removal efficiency of COD in Membrane Bio-reactor increased slightly under the function of filamentous bacteria. However, the negative effects of the higher net water-head differential pressures,the higher block rate of membrane pore and the great quantity of filamentous bacteria at the externalsurface pres...

  16. 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.

  17. Emulsion liquid membrane for selective extraction of Bi(III)

    Institute of Scientific and Technical Information of China (English)

    Bahram Mokhtari; Kobra Pourabdollah

    2015-01-01

    Di(2-ethylhexyl)phosphoric acid was used as extractant of bismuth ions from nitrate medium by emulsion liquid membrane, with Triton X-100 as the biodegradable surfactant in n-pentanol bulk membrane. The novelties and innovative points of this work are the application of emulsion liquid membrane for selective and efficient extraction of bismuth ions as wel as the relevant optimization procedures. The extraction of bismuth ions was evaluated by the yield of extraction. The experimental parameters were evaluated and optimized, including the ratio of di(2-ethylhexyl)phosphoric acid mass concentration to Triton X-100 (1.0%:0.5%), nature of diluent (n-pentanol), nature and concentration of stripping solution (sulfuric acid, 0.5 mol·L−1), stirring speed (1800 r·min−1) and equilibrium time of extraction (20 min), initial feed solution of bismuth (350 mg·L−1) and the volume ratio of internal stripping phase to membrane phase (14). The experimental parameters of kinetic extraction reveal that the bismuth ions can be extracted by 100%.

  18. Liquid Droplets on a Highly Deformable Membrane

    Science.gov (United States)

    Schulman, Rafael; Dalnoki-Veress, Kari

    2015-11-01

    We present measurements of the deformation produced by micro-droplets atop thin elastomeric and glassy free-standing films. Due to the Laplace pressure, the droplets deform the elastic membrane thereby forming a bulge. Thus, there are two angles that define the droplet/membrane geometry: the angle the liquid surface makes with the film and the angle the deformed bulge makes with the film. The contact line geometry is well captured by a Neumann construction which includes contributions from interfacial and mechanical tensions. Finally, we show that a droplet atop a film with biaxial tension assumes an equilibrium shape which is elongated along the axis of high tension.

  19. Assembly Synthesis of Sheet-like Calcite Array and Stable-Vaterite by Supported Liquid Membrane

    Institute of Scientific and Technical Information of China (English)

    SUN,Dong-Mei(孙冬梅); WU,Qing-Sheng(吴庆生)

    2004-01-01

    Sheet-like calcite array and stable vaterite were synthesized by bio-mimetic supported liquid membrane system under different reaction conditions. Both of the FTIR spectra of products showed narrower peak at 1418 cm-1 than that of bulk CaCO3, and that of vaterite has a split in this peak.

  20. Some aspects of ionic liquid blends and additives influencing bulk conductivity of commercial base paper

    OpenAIRE

    Javaid, Salman

    2013-01-01

    In this study, bulk conductivity of commercial base paper impregnated with different ionic liquids blends and additives, through bench coating was investigated. Bulk conductivity of base paper, ion conductive paper and surface sized ion conductive papers with and without the influence of calendering were evaluated at different concentrations of ionic liquids using at resistivity cell and four point probe technique. It was shown that bulk conductivity of base paper was increased by increasing ...

  1. Competitive bulk liquid membrane transport of Co(Ⅱ),Ni(Ⅱ),Zn(Ⅱ),Cd(Ⅱ),Ag(Ⅰ),Cu(Ⅱ)and Mn(Ⅱ),cations using 2,2'-dithio(bis)benzothiazole as carrier

    Institute of Scientific and Technical Information of China (English)

    A.Nezhadali; N.Rabani

    2011-01-01

    A series of competitive metal-ion transport experiments has been performed.Each involved transport from an aqueous source phase across an organic membrane phase into an aqueous receiving phase.The source phase contained equimolar concentration of Co(Ⅱ),Ni(Ⅱ),Zn(Ⅱ),Cd(Ⅱ),Ag(Ⅰ),Cu(Ⅱ)and Mn(Ⅱ)metal cations.The transport experiments of metal cations were carried out by2,2'-dithio(bis)benzothiazole(DTB)in chloroform(CHCl3).The source phase being buffered at range pH of 4-6.5 and receiving phase being buffered at pH 3.The obtained results show that the selectivity and the efficiency of Ag(Ⅰ)transport from aqueous solutions are observed in this investigation.The effect of concentration of palmitic acid in the transport efficiency of Ag(Ⅰ)ion was also conformed.

  2. Composite hollow fiber membranes for organic solvent-based liquid-liquid extraction

    NARCIS (Netherlands)

    He, T.; Versteeg, L.A.M.; Mulder, M.H.V.; Wessling, M.

    2004-01-01

    Instability issues of liquid membranes extraction significantly limit its wide application in industry. We report research on the application of a new composite hollow fiber membrane to stabilizing liquid membrane extraction. These type of composite membranes have either a polysulfone (PSf) ultrafil

  3. Transport through liquid membranes containing omeprazole and lansoprazole.

    Science.gov (United States)

    Nagappa, A N; Pandi, P V; Mishra, P K; Girish, Rahul K; Shanmukh, I

    2002-12-01

    Omeprazole and lansoprazole, the therapeutically important drugs belonging to proton pump inhibitor category are extensively used in the treatment of gastric ulcers. Transport through liquid membranes generated by these drugs in lecithin-cholesterol mixture in series with a supporting membrane has been studied. The data obtained show the formation of liquid membrane in series with the supporting membrane. Transport of cations, chloride and bicarbonate ions in the presence liquid membranes generated by omeprazole and lanzoprazole indicate the modification in the permeability of various permeants.

  4. Interaction of a Spherical Colloid and a Porous Membrane in a Bulk Electrolyte

    Institute of Scientific and Technical Information of China (English)

    LIAN Zeng-Ju

    2011-01-01

    @@ A systemic computation of an electrostatic interaction between a charged spherical colloid and a charged porous membrane with a fixed potential is made under the linear Poisson-Boltzmann theory.The colloid moves along the symmetry axis of the membrane and they are both immersed in a bulk electrolyte.In the calculation,a significant attraction between the colloid and the membrane is found.The orifices on or around the centre of the membrane play a major role in the attraction.The effect of the reduced orifice sizes of the membrane on the interaction is taken into account.Furthermore,the electrostatic interaction energies are significantly changed by the variation of ionic strengths(concentration and valence relating the Dybe length).%A systemic computation of an electrostatic interaction between a charged spherical colloid and a charged porous membrane with a fixed potential is made under the linear Poisson-Boltzmann theory. The colloid moves along the symmetry axis of the membrane and they are both immersed in a bulk electrolyte. In the calculation, a significant attraction between the colloid and the membrane is found. The orifices on or around the centre of the membrane play a major role in the attraction. The effect of the reduced orifice sizes of the membrane on the interaction is taken into account. Furthermore, the electrostatic interaction energies are significantly changed by the variation of ionic strengths (concentration and valence relating the Dybe length).

  5. Substrate-induced bulk alignment of liquid crystals

    DEFF Research Database (Denmark)

    Zhang, Zhengping; Chakrabarti, A.; Mouritsen, Ole G.;

    1996-01-01

    The Gay-Berne model for liquid crystals in the presence of a substrate surface is studied using the hybrid Monte Carlo method. A simple non-mean-field substrate-molecule potential is proposed to describe the effects of rubbed polymer-coated substrates on the liquid crystals. Effects...

  6. Pervaporation and Gas Separation with Supported Liquid Membranes.

    OpenAIRE

    2016-01-01

    The goal of this work is to combine the recent developments in the field of membrane technology, e.g. supported liquid membranes, pervaporation and gas separation with the use of ionic liquids (ILs) for providing novel solutions in downstream processing or process intensification.

  7. Membrane fouling in a submerged membrane bioreactor with focus on surface properties and interactions of cake sludge and bulk sludge.

    Science.gov (United States)

    Yu, Haiying; Lin, Hongjun; Zhang, Meijia; Hong, Huachang; He, Yiming; Wang, Fangyuan; Zhao, Leihong

    2014-10-01

    In this study, the fouling behaviors and surface properties of cake sludge and bulk sludge in a submerged membrane bioreactor (MBR) were investigated and compared. It was found that the specific filtration resistance (SFR) of cake sludge was about 5 times higher than that of bulk sludge. Two types of sludge possessed similar extracellular polymeric substances (EPS) content, particle size distribution (PSD) and zeta potential. However, their surface properties in terms of surface tensions were significantly different. Further analysis showed that cake sludge was more hydrophilic and had worse aggregation ability. Moreover, cake sludge surface possessed more hydrocarbon, less oxygen and nitrogen moieties than bulk sludge surface. It was suggested that, rather than EPS and PSD differences, the differences in the surface composition were the main cause of the great differences in SFR and adhesion ability between cake sludge and bulk sludge.

  8. Supported Liquid Membrane Principle and Its Practices: A Short Review

    Directory of Open Access Journals (Sweden)

    P. K. Parhi

    2013-01-01

    Full Text Available The present paper on the supported liquid membrane (SLM deals with the general principles and applications, followed by the uphill transportation characteristic of SLM. The liquid-liquid extraction with supported liquid membrane is one of the best alternate and promising technologies for the extraction of metal ions from solutions over other hydrometallurgical separation processes. The salient features of the supported liquid membrane (SLM technique such as simultaneous extraction and stripping, low solvent inventory, process economy, high efficiency, less extractant consumption, and operating costs are discussed in detail. The supported liquid membrane of hollow fiber type provides high interfacial surface area for achieving maximum metal flux. Also the use of different organic extractants for SLM has been discussed.

  9. 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

  10. Diffusion coefficient of an inclusion in a liquid membrane supported by a solvent of arbitrary thickness.

    Science.gov (United States)

    Seki, Kazuhiko; Ramachandran, Sanoop; Komura, Shigeyuki

    2011-08-01

    The diffusion coefficient of an inclusion in a liquid membrane is investigated by taking into account the interaction between membranes and bulk solvents of arbitrary thickness. As illustrative examples, the diffusion coefficients of two types of inclusions, a circular domain composed of fluid with the same viscosity as the host membrane and that of a polymer chain embedded in the membrane, are studied. The diffusion coefficients are expressed in terms of the hydrodynamic screening lengths, which vary according to the solvent thickness. When the membrane fluid is dragged by the solvent of finite thickness, via stick boundary conditions, multiple hydrodynamic screening lengths together with the weight factors to the diffusion coefficients are obtained from the characteristic equation. The conditions for which the diffusion coefficients can be approximated by the expression including only a single hydrodynamic screening length are also shown.

  11. 46 CFR 153.957 - Persons in charge of transferring liquid cargo in bulk or cleaning cargo tanks.

    Science.gov (United States)

    2010-10-01

    ... safely transfer liquid cargo in bulk or to safely clean cargo tanks; (2) Each transfer of liquid cargo in... or cleaning cargo tanks. 153.957 Section 153.957 Shipping COAST GUARD, DEPARTMENT OF HOMELAND... transferring liquid cargo in bulk or cleaning cargo tanks. (a) The owner and operator of the vessel, and his...

  12. Linking structure to fragility in bulk metallic glass-forming liquids

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Shuai, E-mail: shuai.wei@asu.edu, E-mail: m.stolpe@mx.uni-saarland.de [Department of Materials Science and Engineering, Saarland University, Campus C63, 66123 Saarbrücken (Germany); Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287 (United States); Stolpe, Moritz, E-mail: shuai.wei@asu.edu, E-mail: m.stolpe@mx.uni-saarland.de; Gross, Oliver; Gallino, Isabella; Hembree, William; Busch, Ralf [Department of Materials Science and Engineering, Saarland University, Campus C63, 66123 Saarbrücken (Germany); Evenson, Zach [Department of Materials Science and Engineering, Saarland University, Campus C63, 66123 Saarbrücken (Germany); Institut für Materialphysik im Weltraum, Deutsches Zentrum für Luft- und Raumfahrt (DLR), 51170 Köln (Germany); Bednarcik, Jozef [Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, D-22603 Hamburg (Germany); Kruzic, Jamie J. [Material Science, School of Mechanical, Industrial, and Manufacturing Engineering, Oregon State University, Corvallis, Oregon 97331 (United States)

    2015-05-04

    Using in-situ synchrotron X-ray scattering, we show that the structural evolution of various bulk metallic glass-forming liquids can be quantitatively connected to their viscosity behavior in the supercooled liquid near T{sub g}. The structural signature of fragility is identified as the temperature dependence of local dilatation on distinct key atomic length scales. A more fragile behavior results from a more pronounced thermally induced dilatation of the structure on a length scale of about 3 to 4 atomic diameters, coupled with shallower temperature dependence of structural changes in the nearest neighbor environment. These findings shed light on the structural origin of viscous slowdown during undercooling of bulk metallic glass-forming liquids and demonstrate the promise of predicting the properties of bulk metallic glasses from the atomic scale structure.

  13. Enzyme biosensor for urea based on a novel pH bulk optode membrane.

    Science.gov (United States)

    Koncki, R; Mohr, G J; Wolfbeis, O S

    1995-01-01

    A new, absorbance-based enzymatic biosensor membrane for determination of urea is described. A lipophilic, fully LED- and diode laser-compatible pH sensitive dye was incorporated into a plasticized, carboxylated poly(vinyl chloride) membrane and served as the optical transducer of the sensor. Urease was covalently linked to the surface of the pH bulk optode membrane to form a very thin cover. The resulting biosensor membrane allows rapid determination of urea over the 0.3 to 100 mM range. The reproducibility, stability, and effects of pH and buffer concentration on the response of sensor are reported. The preparation of the pH transducer and the immobilization of the enzyme are simple and may easily be adopted to other biosensor types.

  14. Polyacrylate membranes for tunable liquid-filled microlenses

    Science.gov (United States)

    Zhang, Wei; Zappe, Hans; Seifert, Andreas

    2013-04-01

    We present the use of polyacrylate membranes for the fabrication of pneumatically actuated variable lenses. Whereas the most commonly used membrane material for tunable liquid-filled lenses is polydimethylsiloxane (PDMS), polyacrylate membranes have the advantages of high resistance to swelling in silicone oil and enhanced compatibility with a wide range of aqueous optical liquids. These features are quantitatively demonstrated by comparing the material properties and performance of PDMS and polyacrylate membrane lenses. The optical transparency of polyacrylate is more than 92%. The surface roughness is below 3.3 nm rms, and reversible elastic deformation could be demonstrated. Optical measurements show that the cutoff frequency of the modulation transfer function of polyacrylate lenses with different liquid fillings, using a reference contrast of 0.2, is more than 1.5 times larger than that of the same system assembled with PDMS membranes filled with water.

  15. Cooperative Effects of Noise and Coupling on Stochastic Dynamics of a Membrane-Bulk Coupling Model

    Institute of Scientific and Technical Information of China (English)

    TANG Jun; JIA Ya; YI Ming

    2009-01-01

    Based on a membrane-bulk coupling cell model proposed by Gomez-Marin et al. [ Phys. Rev. Lett. 98 (2007) 168303], the cooperative effects of noise and coupling on the stochastic dynamical behavior are investigated, For parameters in a certain region, the oscillation can be induced by the cooperative effect of noise and coupling. Whether considering the coupling or not, corresponding coherence resonance phenomena are observed. Furthermore, the effects of two coupling parameters, cell size L and coupling intensity k, on the noise-induced oscillation of membranes are studied. Contrary effects of noise are found in and out of the deterministic oscillatory regions.

  16. Membrane curvature enables N-Ras lipid anchor sorting to liquid-ordered membrane phases

    DEFF Research Database (Denmark)

    Larsen, Jannik Bruun; Jensen, Martin Borch; Bhatia, Vikram Kjøller;

    2015-01-01

    Trafficking and sorting of membrane-anchored Ras GTPases are regulated by partitioning between distinct membrane domains. Here, in vitro experiments and microscopic molecular theory reveal membrane curvature as a new modulator of N-Ras lipid anchor and palmitoyl chain partitioning. Membrane...... curvature was essential for enrichment in raft-like liquid-ordered phases; enrichment was driven by relief of lateral pressure upon anchor insertion and most likely affects the localization of lipidated proteins in general....

  17. 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.

  18. Diagnosis of a Poorly Performing Liquid Hydrogen Bulk Storage Sphere

    Science.gov (United States)

    Krenn, Angela G.

    2011-01-01

    There are two 850,000 gallon Liquid Hydrogen (LH2) storage spheres used to support the Space Shuttle Program; one residing at Launch Pad A and the other at Launch Pad B. The LH2 Sphere at Pad B has had a high boiloff rate since being brought into service in the 1960's. The daily commodity loss was estimated to be approximately double that of the Pad A sphere, and well above the minimum required by the sphere's specification. Additionally, after being re-painted in the late 1990's a "cold spot" appeared on the outer sphere which resulted in a poor paint bond, and mold formation. Thermography was used to characterize the area, and the boiloff rate was continually evaluated. All evidence suggested that the high boiloff rate was caused by an excessive heat leak into the inner sphere due to an insulation void in the annulus. Pad B was recently taken out of Space Shuttle program service which provided a unique opportunity to diagnose the sphere's poor performance. The sphere was drained and inerted, and then opened from the annular relief device on the top where a series of boroscoping operations were accomplished. Boroscoping revealed a large Perlite insulation void in the region of the sphere where the cold spot was apparent. Perlite was then trucked in and off-loaded into the annular void region until the annulus was full. The sphere has not yet been brought back into service.

  19. A lidar technique to quantify surface deposition from atmospheric releases of bulk liquids

    Science.gov (United States)

    Post, Madison J.; Glaes, Thomas; Matta, Joseph; Sommerville, Douglas; Einfeld, Wayne

    We show that a scanning, pulsed lidar can be used to quantify the time history and areal concentration of mass deposited on the ground from an elevated release of bulk liquid. Aircraft measurements, witness car depositions and evaporative modelling crudely support results from analysed lidar data.

  20. SWOT analysis for safer carriage of bulk liquid chemicals in tankers.

    Science.gov (United States)

    Arslan, Ozcan; Er, Ismail Deha

    2008-06-15

    The application of strengths, weaknesses, opportunities and threats (SWOT) analysis to formulation of strategy concerned with the safe carriage of bulk liquid chemicals in maritime tankers was examined in this study. A qualitative investigation using SWOT analysis has been implemented successfully for ships that are designed to carry liquid chemicals in bulk. The originality of this study lies in the use of SWOT analysis as a management tool to formulate strategic action plans for ship management companies, ship masters and officers for the carriage of dangerous goods in bulk. With this transportation-based SWOT analysis, efforts were made to explore the ways and means of converting possible threats into opportunities, and changing weaknesses into strengths; and strategic plans of action were developed for safer tanker operation.

  1. 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.

  2. Bulk and interfacial molecular structure near liquid-liquid critical points

    Energy Technology Data Exchange (ETDEWEB)

    Manzanares-Papayanopoulos, Emilio

    2000-09-01

    Critical behaviour occurs when two coexisting phases merge identity without abrupt change in physical properties. The detail of this behaviour is nowadays considered universal, being dominated by the divergence of the correlation length {xi}. Following this universality, the detailed behaviour can be studied experimentally using any convenient system. For that reason, the study of fluids, and in particular fluid mixtures, offers a useful platform since critical behaviour in such systems can often be studied at convenient temperatures and pressures. Although criticality is a consequence of the divergence of {xi}, and so in a sense is a large-scale phenomenon, nevertheless it has an influence on events at molecular level. This aspect of criticality has received relatively little study compared to the enormous effort expended over the past thirty years in elucidating the macroscopic or phenomenological aspects of criticality. The signature of criticality at molecular level is the central theme running through this research.The aim of the work described in this thesis was to investigate the surface and transport properties of near-critical binary liquid mixtures. The surface properties mainly concerned the adsorption and wetting behaviour at the vapour-liquid and liquid-solid interfaces. The transport property studied was the shear viscosity at bulk or macroscopic level and the corresponding property at molecular or microscopic level, the micro viscosity. The work presented in this thesis comprises the experimental measurements and the theoretical interpretations drawn from the results. The experimental work was varied, using both classical and modern techniques. The theoretical interpretation was used as directed towards validating and comparing the results of the experimental programme with the predictions of the current classical critical-state theories. The systems investigated have been mostly alkane + perfluoroalkane mixtures or mixtures with very similar

  3. Performance evaluation of organic emulsion liquid membrane on phenol removal

    CERN Document Server

    Ng, Y S; Hashim, M A

    2014-01-01

    The percentage removal of phenol from aqueous solution by emulsion liquid membrane and emulsion leakage was investigated experimentally for various parameters such as membrane:internal phase ratio, membrane:external phase ratio, emulsification speed, emulsification time, carrier concentration, surfactant concentration and internal agent concentration. These parameters strongly influence the percentage removal of phenol and emulsion leakage. Under optimum membrane properties, the percentage removal of phenol was as high as 98.33%, with emulsion leakage of 1.25%. It was also found that the necessity of carrier for enhancing phenol removal was strongly dependent on the internal agent concentration.

  4. Supported liquid inorganic membranes for nuclear waste separation

    Energy Technology Data Exchange (ETDEWEB)

    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.

  5. The stability of supported liquid membranes

    NARCIS (Netherlands)

    Neplenbroek, A.M.; Bargeman, D.; Smolders, C.A.

    1990-01-01

    In this paper a new hypothesis about the instability mechanism of SLMs will be discussed: emulsion formation induced by lateral shear forces. Experimental results show that a water phase with a low salt concentration which flows along the membrane interface causes the removal of both solvent and car

  6. Failure Mechanisms of Hollow Fiber Supported Ionic Liquid Membranes.

    Science.gov (United States)

    Zeh, Matthew; Wickramanayake, Shan; Hopkinson, David

    2016-03-23

    Hollow fiber supported ionic liquid membranes (SILMs) were tested using the bubble point method to investigate potential failure modes, including the maximum transmembrane pressure before loss of the ionic liquid from the support. Porous hollow fiber supports were fabricated with different pore morphologies using Matrimid(®) and Torlon(®) as the polymeric material and 1-hexyl-3-methylimidalzolium bis(trifluoromethylsulfonyl)imide ([C₆mim][Tf₂N]) as the ionic liquid (IL) component. Hollow fiber SILMs were tested for their maximum pressure before failure, with pressure applied either from the bore side or shell side. It was found that the membranes exhibited one or more of three different modes of failure when pressurized: liquid loss (occurring at the bubble point), rupture, and collapse.

  7. Secondary and lyotropic liquid crystal membranes for improved aqueous separations

    Science.gov (United States)

    Nemade, Parag Ramesh

    An effective membrane separation process should have high flux (i.e., volume filtered per unit membrane surface area per unit time) and selectivity (i.e., passage of the desired species and rejection of undesired species). This dissertation examined two approaches, secondary membranes and lyotropic liquid crystal membranes, for improving flux and selectivity in aqueous liquid separations. The first part of my work emphasizes the use of pre-deposited secondary membranes and backflushing for controlling membrane fouling in microfiltration and ultrafiltration of biological mixtures. Use of secondary membranes increased the permeate flux in microfiltration by several fold. Protein transmission is also enhanced due to the presence of the secondary membrane, and the amount of protein recovered is more than twice that obtained during filtration of protein-only solutions under otherwise identical conditions. In ultrafiltration, the flux enhancement due to secondary membranes is 50%, or less. For the second part of my research, I developed and evaluated polymerized lyotropic liquid crystal (LLC) thin-film composite membranes. LLC assemblies provide an opportunity to make nanoporous polymer membranes with precise control over chemical and structural features on the nanometer scale, which is currently lacking in commercial reverse osmosis (RO) and nanofiltration (NF) membranes available today. These LLC composite membranes are prepared by photopolymerization of solution-cast films of LLC monomer on an ultrafiltration support membrane. These LLC membranes appeared to exhibit almost linearly increasing ionic rejection based on ionic diameter. LLC monomer was modified to achieve a 15% reduction in channel diameter, through the use of a larger multivalent Eu3+ cation as the carboxylate counterion. However, the monomers synthesized required use of solvents such as tetrahydrofuran, which resulted in the dissolution and damage of the support membranes used. Therefore, this direction

  8. Membrane contactor assisted extraction/reaction process employing ionic liquids

    Science.gov (United States)

    Lin, Yupo J.; Snyder, Seth W.

    2012-02-07

    The present invention relates to a functionalized membrane contactor extraction/reaction system and method for extracting target species from multi-phase solutions utilizing ionic liquids. One preferred embodiment of the invented method and system relates to an extraction/reaction system wherein the ionic liquid extraction solutions act as both extraction solutions and reaction mediums, and allow simultaneous separation/reactions not possible with prior art technology.

  9. 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.

  10. Discotic columnar liquid crystal studied in the bulk and nanoconfined states by molecular dynamics simulation.

    Science.gov (United States)

    Busselez, Rémi; Cerclier, Carole V; Ndao, Makha; Ghoufi, Aziz; Lefort, Ronan; Morineau, Denis

    2014-10-07

    A prototypical Gay Berne discotic liquid crystal was studied by means of molecular dynamics simulations both in the bulk state and under confinement in a nanoporous channel. The phase behavior of the confined system strongly differs from its bulk counterpart: the bulk isotropic-to-columnar transition is replaced by a continuous ordering from a paranematic to a columnar phase. Moreover, a new transition is observed at a lower temperature in the confined state, which corresponds to a reorganization of the intercolumnar order. It reflects the competing effects of pore surface interaction and genuine hexagonal packing of the columns. The translational molecular dynamics in the different phases has been thoroughly studied and discussed in terms of collective relaxation modes, non-Gaussian behavior, and hopping processes.

  11. Membrane Treatment of Liquid Salt Bearing Radioactive Wastes

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-02-25

    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.

  12. Fast-freezing with liquid nitrogen preserves bulk dissolved organic matter concentrations, but not its composition

    DEFF Research Database (Denmark)

    Thieme, Lisa; Graeber, Daniel; Kaupenjohann, Martin;

    2016-01-01

    concentrations, UV-vis absorption and fluorescence excitation–emission matrices combined with parallel factor analysis (PARAFAC). Fast-freezing with liquid nitrogen prevented a significant decrease of DOC concentrations observed after freezing at −18 °C. Nonetheless, the share of PARAFAC components 1 (EXmax......-freezing with liquid nitrogen) on DOM concentrations measured as organic carbon (DOC) concentrations and on spectroscopic properties of DOM from different terrestrial ecosystems (forest and grassland). Fresh and differently frozen throughfall, stemflow, litter leachate and soil solution samples were analyzed for DOC...... component 4 (EXmax: 280 nm, EXmax: 328 nm) to total fluorescence was not affected by freezing. We recommend fast-freezing with liquid nitrogen for preservation of bulk DOC concentrations of samples from terrestrial sources, whereas immediate measuring is preferable to preserve spectroscopic properties...

  13. High temperature ceramic membrane reactors for coal liquid upgrading

    Energy Technology Data Exchange (ETDEWEB)

    Tsotsis, T.T. (University of Southern California, Los Angeles, CA (United States). Dept. of Chemical Engineering); Liu, P.K.T. (Aluminum Co. of America, Pittsburgh, PA (United States)); Webster, I.A. (Unocal Corp., Los Angeles, CA (United States))

    1992-01-01

    Membrane reactors are today finding extensive applications for gas and vapor phase catalytic reactions (see discussion in the introduction and recent reviews by Armor [92], Hsieh [93] and Tsotsis et al. [941]). There have not been any published reports, however, of their use in high pressure and temperature liquid-phase applications. The idea to apply membrane reactor technology to coal liquid upgrading has resulted from a series of experimental investigations by our group of petroleum and coal asphaltene transport through model membranes. Coal liquids contain polycyclic aromatic compounds, which not only present potential difficulties in upgrading, storage and coprocessing, but are also bioactive. Direct coal liquefaction is perceived today as a two-stage process, which involves a first stage of thermal (or catalytic) dissolution of coal, followed by a second stage, in which the resulting products of the first stage are catalytically upgraded. Even in the presence of hydrogen, the oil products of the second stage are thought to equilibrate with the heavier (asphaltenic and preasphaltenic) components found in the feedstream. The possibility exists for this smaller molecular fraction to recondense with the unreacted heavy components and form even heavier undesirable components like char and coke. One way to diminish these regressive reactions is to selectively remove these smaller molecular weight fractions once they are formed and prior to recondensation. This can, at least in principle, be accomplished through the use of high temperature membrane reactors, using ceramic membranes which are permselective for the desired products of the coal liquid upgrading process. An additional incentive to do so is in order to eliminate the further hydrogenation and hydrocracking of liquid products to undesirable light gases.

  14. Proton conducting membrane containing room temperature ionic liquid

    Energy Technology Data Exchange (ETDEWEB)

    Sekhon, S.S. [Department of Applied Physics, Guru Nanak Dev University, Amritsar 143005 (India) and Polymer Electrolyte Fuel Cell Research Department, Korea Institute of Energy Research, 71-2, Jang-Dong, Yusong-gu, Daejeon 305-343 (Korea, Republic of)]. E-mail: sekhon_apd@yahoo.com; Krishnan, P. [Polymer Electrolyte Fuel Cell Research Department, Korea Institute of Energy Research, 71-2, Jang-Dong, Yusong-gu, Daejeon 305-343 (Korea, Republic of); Singh, Boor [Department of Applied Physics, Guru Nanak Dev University, Amritsar 143005 (India); Yamada, K. [Department of Chemistry, Graduate School of Science, Hiroshima University, Higashi-Hiroshima (Japan); Kim, C.S. [Polymer Electrolyte Fuel Cell Research Department, Korea Institute of Energy Research, 71-2, Jang-Dong, Yusong-gu, Daejeon 305-343 (Korea, Republic of)

    2006-12-01

    A new proton conducting membrane containing room temperature ionic liquid: 2,3-dimethyl-1-octylimidazolium trifluoromethanesulfonylimide (DMOImTFSI) and polyvinylidenefluoride-co-hexafluoropropylene (PVdF-HFP) has been developed in the present work. The addition of bis(trifluoromethanesulphonyl)imide (HN(CF{sub 3}SO{sub 2}){sub 2}) to this membrane results in an increase in conductivity by one order of magnitude at 25 deg. C. The membrane shows a conductivity of 2.74 x 10{sup -3} S/cm at 130 deg. C along with good mechanical stability. The membrane was tested in a commercial fuel cell test station at 100 deg. C with dry hydrogen and oxygen gas reactants using Pt/C electrodes. The membrane containing the ionic liquid has been found to be electroactive for hydrogen oxidation and oxygen reduction at the platinum electrode and can be developed for use in proton exchange membrane fuel cell (PEMFC) under non-humid conditions at elevated temperatures.

  15. Survey of transportation of liquid bulk chemicals in the Baltic Sea

    Energy Technology Data Exchange (ETDEWEB)

    Posti, A.; Hakkinen, J.

    2012-07-01

    This study is made as a part of the Chembaltic (Risks of Maritime Transportation of Chemicals in Baltic Sea) project which gathers information on the chemicals transported in the Baltic Sea. The purpose of this study is to provide an overview of handling volumes of liquid bulk chemicals (including liquefied gases) in the Baltic Sea ports and to find out what the most transported liquid bulk chemicals in the Baltic Sea are. Oil and oil products are also viewed in this study but only in a general level. Oils and oil products may also include chemical-related substances (e.g. certain bio-fuels which belong to MARPOL annex II category) in some cargo statistics. Chemicals in packaged form are excluded from the study. Most of the facts about the transport volumes of chemicals presented in this study are based on secondary written sources of Scandinavian, Russian, Baltic and international origin. Furthermore, statistical sources, academic journals, periodicals, newspapers and in later years also different homepages on the Internet have been used as sources of information. Chemical handling volumes in Finnish ports were examined in more detail by using a nationwide vessel traffic system called PortNet. Many previous studies have shown that the Baltic Sea ports are annually handling more than 11 million tonnes of liquid chemicals transported in bulk. Based on this study, it appears that the number may be even higher. The liquid bulk chemicals account for approximately 4 % of the total amount of liquid bulk cargoes handled in the Baltic Sea ports. Most of the liquid bulk chemicals are handled in Finnish and Swedish ports and their proportion of all liquid chemicals handled in the Baltic Sea is altogether over 50 %. The most handled chemicals in the Baltic Sea ports are methanol, sodium hydroxide solution, ammonia, sulphuric and phosphoric acid, pentanes, aromatic free solvents, xylenes, methyl tert-butyl ether (MTBE) and ethanol and ethanol solutions. All of these chemicals

  16. Viscosity properties and strong liquid behavior of Pr60Ni25Al15 bulk metallic glass-forming liquids

    Institute of Scientific and Technical Information of China (English)

    WANG Dan; ZHANG Di; WANG ShuYing; NING QianYan; ZHENG CaiPing; YAN Yuan; LIU Jia; SUN MinHua

    2008-01-01

    Pr60Ni25Al15 bulk metallic glass in a cuboid form with dimensions of 2 mm×2 mm×55 mm by copper mold casting method was cast.The dynamic viscosity near the glass transition region for Pr60Ni25Al15 was measured by three-point beam bending methods.The fragility parameter m and activation energy for viscous flow of the liquid sample were calculated to be: m = 31.66, E= 10689.17 K, respectively.It was shown that the supercooled liquid of Pr60Ni25Al15 alloy behaved much closer to strong glasses.The variation of active energy with temperature in supercooled liquid was analyzed.It was found that Kivelson's super-Arrhenius equation is not suitable for description of the activation energy in a supercooled region of Bulk metallic glass, and there is a direct proportion between activation energy crystal-lization and activation energy of viscous flow.

  17. Viscosity properties and strong liquid behavior of Pr60Ni25Al15 bulk metallic glass-forming liquids

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Pr60Ni25Al15 bulk metallic glass in a cuboid form with dimensions of 2 mm×2 mm×55 mm by copper mold casting method was cast. The dynamic viscosity near the glass transition region for Pr60Ni25Al15 was measured by three-point beam bending methods. The fragility parameter m and activation energy for viscous flow of the liquid sample were calculated to be:m=31.66,E=10689.17 K,respectively. It was shown that the supercooled liquid of Pr60Ni25Al15 alloy behaved much closer to strong glasses. The variation of active energy with temperature in supercooled liquid was analyzed. It was found that Kivelson’s super-Arrhenius equation is not suitable for description of the activation energy in a supercooled region of Bulk metallic glass,and there is a direct proportion between activation energy crystal-lization and activation energy of viscous flow.

  18. An ab initio study of the structure and atomic transport in bulk liquid Ag and its liquid-vapor interface

    Science.gov (United States)

    del Rio, Beatriz G.; González, David J.; González, Luis E.

    2016-10-01

    Several static and dynamic properties of bulk liquid Ag at a thermodynamic state near its triple point have been calculated by means of ab initio molecular dynamics simulations. The calculated static structure shows a very good agreement with the available experimental data. The dynamical structure reveals propagating excitations whose dispersion at long wavelengths is compatible with the experimental sound velocity. Results are also reported for other transport coefficients. Additional simulations have also been performed so as to study the structure of the free liquid surface. The calculated longitudinal ionic density profile shows an oscillatory behaviour, whose properties are analyzed through macroscopic and microscopic methods. The intrinsic X-ray reflectivity of the surface is predicted to show a layering peak associated to the interlayer distance.

  19. Ion Transport in Nanostructured Block Copolymer/Ionic Liquid Membranes

    Science.gov (United States)

    Hoarfrost, Megan Lane

    Incorporating an ionic liquid into one block copolymer microphase provides a platform for combining the outstanding electrochemical properties of ionic liquids with a number of favorable attributes provided by block copolymers. In particular, block copolymers thermodynamically self-assemble into well-ordered nanostructures, which can be engineered to provide a durable mechanical scaffold and template the ionic liquid into continuous ion-conducting nanochannels. Understanding how the addition of an ionic liquid affects the thermodynamic self-assembly of block copolymers, and how the confinement of ionic liquids to block copolymer nanodomains affects their ion-conducting properties is essential for predictable structure-property control. The lyotropic phase behavior of block copolymer/ionic liquid mixtures is shown to be reminiscent of mixtures of block copolymers with selective molecular solvents. A variety of ordered microstructures corresponding to lamellae, hexagonally close-packed cylinders, body-centered cubic, and face-centered cubic oriented micelles are observed in a model system composed of mixtures of imidazolium bis(trifluoromethylsulfonyl)imide ([Im][TFSI]) and poly(styrene- b-2-vinyl pyridine) (PS-b-P2VP). In contrast to block copolymer/molecular solvent mixtures, the interfacial area occupied by each PS-b-P2VP chain decreases upon the addition of [Im][TFSI], indicating a considerable increase in the effective segregation strength of the PS-b-P2VP copolymer with ionic liquid addition. The relationship between membrane structure and ionic conductivity is illuminated through the development of scaling relationships that describe the ionic conductivity of block copolymer/ionic liquid mixtures as a function of membrane composition and temperature. It is shown that the dominant variable influencing conductivity is the overall volume fraction of ionic liquid in the mixture, which means there is incredible freedom in designing the block copolymer architecture

  20. Elastic properties of Pd40Cu30Ni10P20 bulk glass in supercooled liquid region

    DEFF Research Database (Denmark)

    Nishiyama, N.; Inoue, A.; Jiang, Jianzhong

    2001-01-01

    In situ ultrasonic measurements for the Pd40Cu30Ni10P20 bulk glass in three states: Glassy solid, supercooled liquid, and crystalline, have been performed. It is found that velocities of both longitudinal and transverse waves and elastic moduli (shear modulus, bulk modulus, Young's modulus, and L...

  1. Inner Structure of Boiling Nucleus and Interfacial Energy Between Nucleus and Bulk Liquid

    Institute of Scientific and Technical Information of China (English)

    WANG Xiao-Dong; TIAN Yong; PENG Xiao-Feng; WANG Bu-Xuan

    2004-01-01

    @@ A model of two-region structure of a nucleus is proposed to describe nucleus evolution. The interfacial tension between bulk liquid phase and nucleus is dependent on the density gradient in the transition region and varies with the structure change of the transition region. With the interfacial tension calculated using this model, the predicted nucleation rate is very close to the experimental measurement. Furthermore, this model and associated analysis provide solid theoretical evidence to clarify the definition of nucleation rate and understand the nucleation phenomenon with insight into the physical nature.

  2. Fast-freezing with liquid nitrogen preserves bulk dissolved organic matter concentrations, but not its composition

    Science.gov (United States)

    Thieme, Lisa; Graeber, Daniel; Kaupenjohann, Martin; Siemens, Jan

    2016-08-01

    Freezing can affect concentrations and spectroscopic properties of dissolved organic matter (DOM) in water samples. Nevertheless, water samples are regularly frozen for sample preservation. In this study we tested the effect of different freezing methods (standard freezing at -18 °C and fast-freezing with liquid nitrogen) on DOM concentrations measured as organic carbon (DOC) concentrations and on spectroscopic properties of DOM from different terrestrial ecosystems (forest and grassland). Fresh and differently frozen throughfall, stemflow, litter leachate and soil solution samples were analyzed for DOC concentrations, UV-vis absorption and fluorescence excitation-emission matrices combined with parallel factor analysis (PARAFAC). Fast-freezing with liquid nitrogen prevented a significant decrease of DOC concentrations observed after freezing at -18 °C. Nonetheless, the share of PARAFAC components 1 (EXmax nitrogen for preservation of bulk DOC concentrations of samples from terrestrial sources, whereas immediate measuring is preferable to preserve spectroscopic properties of DOM.

  3. Designing lipids for selective partitioning into liquid ordered membrane domains.

    Science.gov (United States)

    Momin, Noor; Lee, Stacey; Gadok, Avinash K; Busch, David J; Bachand, George D; Hayden, Carl C; Stachowiak, Jeanne C; Sasaki, Darryl Y

    2015-04-28

    Self-organization of lipid molecules into specific membrane phases is key to the development of hierarchical molecular assemblies that mimic cellular structures. While the packing interaction of the lipid tails should provide the major driving force to direct lipid partitioning to ordered or disordered membrane domains, numerous examples show that the headgroup and spacer play important but undefined roles. We report here the development of several new biotinylated lipids that examine the role of spacer chemistry and structure on membrane phase partitioning. The new lipids were prepared with varying lengths of low molecular weight polyethylene glycol (EGn) spacers to examine how spacer hydrophilicity and length influence their partitioning behavior following binding with FITC-labeled streptavidin in liquid ordered (Lo) and liquid disordered (Ld) phase coexisting membranes. Partitioning coefficients (Kp Lo/Ld) of the biotinylated lipids were determined using fluorescence measurements in studies with giant unilamellar vesicles (GUVs). Compared against DPPE-biotin, DPPE-cap-biotin, and DSPE-PEG2000-biotin lipids, the new dipalmityl-EGn-biotin lipids exhibited markedly enhanced partitioning into liquid ordered domains, achieving Kp of up to 7.3 with a decaethylene glycol spacer (DP-EG10-biotin). We further demonstrated biological relevance of the lipids with selective partitioning to lipid raft-like domains observed in giant plasma membrane vesicles (GPMVs) derived from mammalian cells. Our results found that the spacer group not only plays a pivotal role for designing lipids with phase selectivity but may also influence the structural order of the domain assemblies.

  4. Porous Membranes Built Up from Hydrophilic Poly(ionic liquid)s.

    Science.gov (United States)

    Täuber, Karoline; Zimathies, Annett; Yuan, Jiayin

    2015-12-01

    Porous polymer membranes made via electrostatic complexation are fabricated from a water-soluble poly(ionic liquid) (PIL) for the first time. The porous structure is formed as a consequence of simultaneous phase separation of the PIL and ionic complexation with an acid, which occurred in a basic solution of a nonsolvent for the PIL. These membranes have a stimuli-responsive porosity, with open and closed pores in isopropanol and in water, respectively. This property is quantitatively demonstrated in filtration experiments, where water is passing much slower through the membranes than isopropanol.

  5. Manufacturing Solid Dosage Forms from Bulk Liquids Using the Fluid-bed Drying Technology.

    Science.gov (United States)

    Qi, Jianping; Lu, Y I; Wu, Wei

    2015-01-01

    Solid dosage forms are better than liquid dosage forms in many ways, such as improved physical and chemical stability, ease of storage and transportation, improved handling properties, and patient compliance. Therefore, it is required to transform dosage forms of liquid origins into solid dosage forms. The functional approaches are to absorb the liquids by solid excipients or through drying. The conventional drying technologies for this purpose include drying by heating, vacuum-, freeze- and spray-drying, etc. Among these drying technologies, fluidbed drying emerges as a new technology that possesses unique advantages. Fluid-bed drying or coating is highly efficient in solvent removal, can be performed at relatively low temperatures, and is a one-step process to manufacture formulations in pellet forms. In this article, the status of the art of manufacturing solid dosage forms from bulk liquids by fluid-bed drying technology was reviewed emphasizing on its application in solid dispersion, inclusion complexes, self-microemulsifying systems, and various nanoscale drug delivery systems.

  6. Li-Doped Ionic Liquid Electrolytes: From Bulk Phase to Interfacial Behavior

    Science.gov (United States)

    Haskins, Justin B.; Lawson, John W.

    2016-01-01

    Ionic liquids have been proposed as candidate electrolytes for high-energy density, rechargeable batteries. We present an extensive computational analysis supported by experimental comparisons of the bulk and interfacial properties of a representative set of these electrolytes as a function of Li-salt doping. We begin by investigating the bulk electrolyte using quantum chemistry and ab initio molecular dynamics to elucidate the solvation structure of Li(+). MD simulations using the polarizable force field of Borodin and coworkers were then performed, from which we obtain an array of thermodynamic and transport properties. Excellent agreement is found with experiments for diffusion, ionic conductivity, and viscosity. Combining MD simulations with electronic structure computations, we computed the electrochemical window of the electrolytes across a range of Li(+)-doping levels and comment on the role of the liquid environment. Finally, we performed a suite of simulations of these Li-doped electrolytes at ideal electrified interfaces to evaluate the differential capacitance and the equilibrium Li(+) distribution in the double layer. The magnitude of differential capacitance is in good agreement with our experiments and exhibits the characteristic camel-shaped profile. In addition, the simulations reveal Li(+) to be highly localized to the second molecular layer of the double layer, which is supported by additional computations that find this layer to be a free energy minimum with respect to Li(+) translation.

  7. Macroscopic Properties of Restacked, Redox-Liquid Exfoliated Graphite and Graphite Mimics Produced in Bulk Quantities

    Energy Technology Data Exchange (ETDEWEB)

    Srivastava, Vikram K [ORNL; Quinlan, Ronald [ORNL; Agapov, Alexander L [ORNL; Dunlap, John R [ORNL; Nelson, Kimberly M [ORNL; Duranty, Edward R [ORNL; Sokolov, Alexei P [ORNL; Bhat, Gajanan [ORNL; Mays, Jimmy [ORNL

    2014-01-01

    The excellent properties exhibited by monolayer graphene have spurred the development of exfoliation techniques using bulk graphite to produce large quantities of pristine monolayer sheets. Development of simple chemistry to exfoliate and intercalate graphite and graphite mimics in large quantities is required for numerous applications. To determine the macroscopic behavior of restacked, exfoliated bulk materials, a systematic approach is presented using a simple, redox-liquid sonication process along to obtain large quantities of 2D and 3D hexagonally layered graphite, molybdenum disulfi de, and boron nitride, which are subsequently characterized to observe chemical and structural changes. For MoS 2 sonicated with the antioxidant sodium bisulfi te, results from Raman spectroscopy, X-ray diffraction, and electron microscopy indicate the presence of distorted phases from different polymorphs, and apparent nanotube structures in the bulk, restacked powder. Furthermore, using thermograviemtric analysis, the antioxidant enhances the resistance to oxidative degradation of MoS 2 , upon thermal treatment up to 900 C. The addition of the ionic antioxidant decreased dispersion stability in non-polar solvent, suggesting decreased compatibility with non-polar systems. Using simple chemical methods, the ability to generate tailored multidimensional layered materials with unique macroscopic properties is critical for numerous applications, including electrical devices, reinforced polymer composites, lithium ion capacitors, and chemical sensing.

  8. 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

  9. Electroactive liquid lens driven by an annular membrane.

    Science.gov (United States)

    Wei, Kang; Domicone, Nicholas Wade; Zhao, Yi

    2014-03-01

    Unlike traditional focalization that recruits multiple moving lens elements to adjust focus, liquid lenses deliver adaptive focusing by simply tuning the surface profile of liquid or the elastomer that encloses liquid. Its simple and compact configuration, low cost, and actuation efficiency promise wide industrial, medical, and consumer applications. Dielectric elastomers (DEs), one type of commercially available soft active material, have been a good fit for creating adaptive optics. In this Letter, we present an adaptive, membrane-sealed liquid lens hydrostatically coupled to a concentric annular DE actuator. Electric actuation deforms the annular DE, which induces fluid transmission between the lens part and the actuation part for lens actuation. The maximum measured focal range was from 25.4 to 105.2 mm within 1.0 kV, which significantly outperforms the existing DE-actuated liquid lenses and eliminates the need for prestraining. The lens also enables varied focal ranges by simply adjusting its initial surface sagitta, providing flexibility for practical imaging applications.

  10. 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.

  11. New absorption liquids for the removal of CO2 from dilute gas streams using membrane contactors

    NARCIS (Netherlands)

    Kumar, P.S.; Hogendoorn, J.A.; Feron, P.H.M.; Versteeg, G.F.

    2002-01-01

    A new absorption liquid based on amino acid salts has been studied for CO2 removal in membrane gas-liquid contractors. Unlike conventional gas treating solvents like aqueous alkanolamines solutions, the new absorption liquid does not wet polyolefin microporous membranes. The wetting characteristics

  12. Supported liquid membranes in 1986: new technology or scientific curiosity

    Energy Technology Data Exchange (ETDEWEB)

    Danesi, P.R.

    1986-01-01

    Thin layers of organic solutions of solvent extraction reagents (membrane carriers), immobilized on microporous inert supports and interposed between two aqueous solutions (feed and strip), were first proposed more than two decades ago as a new and promising technique for separating and concentrating metal species. Such immobilized layers, representing supported liquid membranes (SLM), have been extensively studies by our group during the last six years mainly for their ability to separate and concentrate metal ions of critical and strategic importance and of relevance to the nuclear industry. In this presentation the major results obtained by our group up to 1986 in the field of SLM's are summarized. A brief indication of the major problems to be addressed to implement SLM's as a new separation technology is also given. 5 refs., 5 figs., 3 tabs.

  13. New, ionic liquid-based membranes for lithium battery application

    Energy Technology Data Exchange (ETDEWEB)

    Sirisopanaporn, C.; Fernicola, A.; Scrosati, B. [Department of Chemistry, University of Rome La Sapienza, 00185 Rome (Italy)

    2009-01-15

    New types of dimensionally stable, flexible gel-type electrolyte membranes with a relatively wide electrochemical stability, high lithium ion conductivity and other desirable properties have been prepared by immobilizing N-n-butyl-N-ethylpyrrolidinium N,N-bis(trifluoromethane)sulfonimide-lithium N,N-bis(trifluoromethane)sulfonimide (Py{sub 24}TFSI-LiTFSI), ionic liquid, IL, solutions in a poly(vinylidene fluoride)-hexafluoropropylene copolymer (PVdF-HFP) matrix. The addition of a discrete amount of ethylene and propylene carbonate (EC-PC), solvent mixture to the membranes resulted in an improvement of the ionic conductivity and in a stabilization of the interface with the lithium electrode. These IL-based gel type membranes can operate without degradation up to a temperature of 110 C where they reach conductivity values of the order of 10{sup -2} S cm{sup -1}. All these properties make these polymer electrolyte membranes of interest for applications as separators in advanced lithium batteries. (author)

  14. Mechanical characterization of selected adhesives and bulk materials at liquid nitrogen and room temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Fitzpatrick, C.M.; Stoddart, W.C.T.

    1977-01-01

    This paper presents the results of a series of mechanical tests on selected adhesives and bulk materials. The materials tested are of general interest to designers of magnets for cryogenic service and include several epoxies, a varnish, a B-stage glass cloth, insulation papers, and commercially available fiber-reinforced composites. These tests were performed at room temperature (293 K) and at liquid nitrogen temperature (77 K). The tests include both simple tension tests and lap shear tests with various adherends. The parameters critical to tensile or bond strength were varied as part of the test program. The procedures used to manufacture and test these specimens and the results of the tests are reported in this paper.

  15. Characterization of impurities in the bulk drug lisinopril by liquid chromatography/ion trap spectrometry

    Institute of Scientific and Technical Information of China (English)

    Pei-xi ZHU; Dan-hun WANG; Cui-rong SUN; Zhi-quan SHEN

    2008-01-01

    Two trace impurities in the bulk drug lisinopril were detected by means of high-performance liquid chromatography coupled with mass spectrometry (HPLC/MS) with a simple and sensitive method suitable for HPLC/MSn analysis.The frag-mentation behavior of lisinopril and the impurities was investigated,and two unknown impurities were elucidated as 2-(6-amino-1-(1-earboxyethylamino)-1-oxohexan-2-ylamino)-4-phenylbutanoic acid and 6-amino-2-(1-carboxy-3-phenylpro-pylamino)-hexanoic acid on the basis of the multi-stage mass spectrometry and exact mass evidence.The proposed structures of the two unknown impurities were further confirmed by nuclear magnetic resonance (NMR) experiments after preparative isola-tion.

  16. AC Calorimetry and Thermophysical Properties of Bulk Glass-Forming Metallic Liquids

    Science.gov (United States)

    Johnson, William L.

    2000-01-01

    Thermo-physical properties of two bulk metallic glass forming alloys, Ti34Zr11Cu47Ni8 (VIT 101) and Zr57Nb5Ni12.6Al10CU15.4 (VIT 106), were investigated in the stable and undercooled melt. Our investigation focused on measurements of the specific heat in the stable and undercooled liquid using the method of AC modulation calorimetry. The VIT 106 exhibited a maximum undercooling of 140 K in free radiative cooling. Specific heat measurements could be performed in stable melt down to an undercooling of 80 K. Analysis of the specific heat data indicate an anomaly near the equilibrium liquidus temperature. This anomaly is also observed in y the temperature dependencies of the external relaxation time, the specific volume, and the surface tension; it is tentatively attributed to a phase separation in the liquid state. The VIT 101 specimen exhibited a small undercooling of about 50 K. Specific heat measurements were performed in the stable and undercooled melt. These various results will be combined with ground based work such as the measurement of T-T-T curves in the electrostatic levitator and low temperature viscosity and specific heat measurements for modeling the nucleation kinetics of these alloys.

  17. Cyclic peptides-assisted trans- port of metal ions across liquid-organic membrane

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The formation of alkali and alkaline-earth metal picrate complexes with cyclo(Pro-Gly)n ionophores (1, n = 3; 2, n = 4) can facilitate the migration of metal ions across a bulk liquid CH2Cl2 membrane. The migration behavior was studied by measuring the solution absorption at 356 nm, using a UV/Vis spectrophotometer, and the rates can be determined by comparing the initial absorption of donor solutions with the absorption of the corresponding receiver solutions as the function of time. It was found that cyclic peptide 1 shows higher transport activity for the studied alkali and alkaline-earth metal ions than compound 2, which is related to the backbone flexibility of the cyclic peptides. The findings in this work suggest that the rate of ionophore-facilitated ion transport depends not only on the ability of complex forma-tion in aqueous phase, but also on the ability of complex dissociation in organic phase.

  18. The interplay between dynamic heterogeneities and structure of bulk liquid water: A molecular dynamics simulation study

    Energy Technology Data Exchange (ETDEWEB)

    Demontis, Pierfranco; Suffritti, Giuseppe B. [Dipartimento di Chimica e Farmacia, Università degli studi di Sassari, Sassari (Italy); Consorzio Interuniversitario Nazionale per la Scienza e Tecnologia dei Materiali (INSTM), Unità di ricerca di Sassari, Via Vienna, 2, I-07100 Sassari (Italy); Gulín-González, Jorge [Grupo de Matemática y Física Computacionales, Universidad de las Ciencias Informáticas (UCI), Carretera a San Antonio de los Baños, Km 21/2, La Lisa, La Habana (Cuba); Masia, Marco [Dipartimento di Chimica e Farmacia, Università degli studi di Sassari, Sassari (Italy); Consorzio Interuniversitario Nazionale per la Scienza e Tecnologia dei Materiali (INSTM), Unità di ricerca di Sassari, Via Vienna, 2, I-07100 Sassari (Italy); Istituto Officina dei Materiali del CNR, UOS SLACS, Via Vienna 2, 07100 Sassari (Italy); Sant, Marco [Dipartimento di Chimica e Farmacia, Università degli studi di Sassari, Sassari (Italy)

    2015-06-28

    In order to study the interplay between dynamical heterogeneities and structural properties of bulk liquid water in the temperature range 130–350 K, thus including the supercooled regime, we use the explicit trend of the distribution functions of some molecular properties, namely, the rotational relaxation constants, the atomic mean-square displacements, the relaxation of the cross correlation functions between the linear and squared displacements of H and O atoms of each molecule, the tetrahedral order parameter q and, finally, the number of nearest neighbors (NNs) and of hydrogen bonds (HBs) per molecule. Two different potentials are considered: TIP4P-Ew and a model developed in this laboratory for the study of nanoconfined water. The results are similar for the dynamical properties, but are markedly different for the structural characteristics. In particular, for temperatures higher than that of the dynamic crossover between “fragile” (at higher temperatures) and “strong” (at lower temperatures) liquid behaviors detected around 207 K, the rotational relaxation of supercooled water appears to be remarkably homogeneous. However, the structural parameters (number of NNs and of HBs, as well as q) do not show homogeneous distributions, and these distributions are different for the two water models. Another dynamic crossover between “fragile” (at lower temperatures) and “strong” (at higher temperatures) liquid behaviors, corresponding to the one found experimentally at T{sup ∗} ∼ 315 ± 5 K, was spotted at T{sup ∗} ∼ 283 K and T{sup ∗} ∼ 276 K for the TIP4P-Ew and the model developed in this laboratory, respectively. It was detected from the trend of Arrhenius plots of dynamic quantities and from the onset of a further heterogeneity in the rotational relaxation. To our best knowledge, it is the first time that this dynamical crossover is detected in computer simulations of bulk water. On the basis of the simulation results, the possible

  19. Dynamic single-interface hollow fiber liquid phase microextraction of Cr(VI) using ionic liquid containing supported liquid membrane.

    Science.gov (United States)

    Pimparu, Rungaroon; Nitiyanontakit, Sira; Miró, Manuel; Varanusupakul, Pakorn

    2016-12-01

    The concept of dynamic single-interface hollow fiber membrane liquid-phase microextraction (HF-LPME), where the target analyte was extracted on-line and eluted inside the lumen of the HF membrane, was explored. An ionic liquid containing supported liquid membrane was used for the trace determination of Cr(VI) as a model compound. Since the extraction took place on-line inside the hollow fiber membrane, the mass transfer behavior was described and discussed in comparison with the conventional HF-LPME. The extraction efficiency was improved by a recirculation configuration of the sample solution at relatively high sampling flow rates as a result of the increased effective contact area. The positive pressure observed to be built up during extraction was overcome by a flow-balancing pressure design. The dynamic single-interface HF-LPME method with an enrichment factor of 41, a detection limit of 1.2µgL(-1) and determination limit of 4.0µgL(-1) was successfully applied to the reliable determination of Cr(VI) from environmental water samples. The quantification limit is below the maximum contaminant level in drinking water, set at 10µgL(-1) of hexavalent chromium by the California Environmental Protection Agency.

  20. Acoustoelectric effects in reflection of leaky-wave-radiated bulk acoustic waves from piezoelectric crystal-conductive liquid interface.

    Science.gov (United States)

    Rimeika, Romualdas; Čiplys, Daumantas; Jonkus, Vytautas; Shur, Michael

    2016-01-01

    The leaky surface acoustic wave (SAW) propagating along X-axis of Y-cut lithium tantalate crystal strongly radiates energy in the form of an obliquely propagating narrow bulk acoustic wave (BAW) beam. The reflection of this beam from the crystal-liquid interface has been investigated. The test liquids were solutions of potassium nitrate in distilled water and of lithium chloride in isopropyl alcohol with the conductivity varied by changing the solution concentration. The strong dependences of the reflected wave amplitude and phase on the liquid conductivity were observed and explained by the acoustoelectric interaction in the wave reflection region. The novel configuration of an acoustic sensor for liquid media featuring important advantages of separate measuring and sensing surfaces and rigid structure has been proposed. The application of leaky-SAW radiated bulk waves for identification of different brands of mineral water has been demonstrated.

  1. Supported Liquid Membrane Extraction Technology and Its Application in Detection of Meat Security

    Institute of Scientific and Technical Information of China (English)

    LIU Jia; LI Weijin

    2010-01-01

    As a novel technology, supported liquid membrane extraction has gradually become the direction of the research of extraction, for the advantages of using little organic solvents, good selectivity and repeatability. This paper is based on describing the working principle, structure and influencing factors of supported liquid membrane, and research in domestic and foreign literatures which are in the same period, and give a review on the application of supported liquid membrane in meat security determination.

  2. Occurrence of heterotrophic and coliform bacteria in liquid hand soaps from bulk refillable dispensers in public facilities.

    Science.gov (United States)

    Chattman, Marisa; Gerba, Sheri L; Maxwell, Charles P

    2011-03-01

    The goal of the study discussed in this article was to determine the occurrence of heterotrophic and coliform bacteria in liquid soap from bulk refillable dispensers, obtained from restrooms in a variety of public facilities. A total of 541 samples was collected from five U.S. cities. Liquid soap from dispensers in public areas was found to contain heterotrophic and coliform bacterial numbers averaging more than 106 CFU/mL in 24.8% of the dispensers.

  3. Hollow fiber membrane contactor as a gas–liquid model contactor

    NARCIS (Netherlands)

    Dindore, V.Y.; Brilman, D.W.F.; Versteeg, G.F.

    2005-01-01

    Microporous hollow fiber gas–liquid membrane contactors have a fixed and well-defined gas–liquid interfacial area. The liquid flow through the hollow fiber is laminar, thus the liquid side hydrodynamics are well known. This allows the accurate calculation of the fiber side physical mass transfer coe

  4. Hollow fiber membrane contactor as a gas-liquid model contactor

    NARCIS (Netherlands)

    Dindore, V. Y.; Brilman, D. W. F.; Versteeg, G. F.

    2005-01-01

    Microporous hollow fiber gas-liquid membrane contactors have a fixed and well-defined gas-liquid interfacial area. The liquid flow through the hollow fiber is laminar, thus the liquid side hydrodynamics are well known. This allows the accurate calculation of the fiber side physical mass transfer coe

  5. Ionic Liquids and New Proton Exchange Membranes for Fuel Cells

    Science.gov (United States)

    Belieres, Jean-Philippe

    2004-01-01

    There is currently a great surge of activity in fuel cell research as laboratories across the world seek to take advantage of the high energy capacity provided by &el cells relative to those of other portable electrochemical power systems. Much of this activity is aimed at high temperature fie1 cells, and a vital component of such &el cells must be the availability of a high temperature stable proton-permeable membrane. NASA Glenn Research Center is greatly involved in developing this technology. Other approaches to the high temperature fuel cell involve the use of single- component or almost-single-component electrolytes that provide a path for protons through the cell. A heavily researched case is the phosphoric acid fuel cell, in which the electrolyte is almost pure phosphoric acid and the cathode reaction produces water directly. The phosphoric acid fie1 cell delivers an open circuit voltage of 0.9 V falling to about 0.7 V under operating conditions at 170 C. The proton transport mechanism is mainly vehicular in character according to the viscosity/conductance relation. Here we describe some Proton Transfer Ionic Liquids (PTILs) with low vapor pressure and high temperature stability that have conductivities of unprecedented magnitude for non-aqueous systems. The first requirement of an ionic liquid is that, contrary to experience with most liquids consisting of ions, it must have a melting point that is not much above room temperature. The limit commonly suggested is 100 C. PTILs constitute an interesting class of non-corrosive proton-exchange electrolyte, which can serve well in high temperature (T = 100 - 250 C) fuel cell applications. We will present cell performance data showing that the open circuit voltage output, and the performance of a simple H2(g)Pt/PTIL/Pt/O2(g) fuel cell may be superior to those of the equivalent phosphoric acid electrolyte fuel cell both at ambient temperature and temperatures up to and above 200 C. My work at NASA Glenn Research

  6. Development of membrane cryostats for large liquid argon neutrino detectors

    CERN Document Server

    Montanari, D; Gendotti, A; Geynisman, M; Hentschel, S; Loew, T; Mladenov, D; Montanari, C; Murphy, S; Nessi, M; Norris, B; Noto, F; Rubbia, A; Sharma, R; Smargianaki, D; Stewart, J; Vignoli, C; Wilson, P; Wu, S

    2015-01-01

    A new collaboration is being formed to develop a multi-kiloton Long-Baseline neutrino experiment that will be located at the Surf Underground Research Facility (SURF) in Lead, SD. In the present design, the detector will be located inside cryostats filled with 68,400 ton of ultrapure liquid argon (less than 100 parts per trillion of oxygen equivalent contamination). To qualify the membrane technology for future very large-scale and underground implementations, a strong prototyping effort is ongoing: several smaller detectors of growing size with associated cryostats and cryogenic systems will be designed and built at Fermilab and CERN. They will take physics data and test different detector elements, filtration systems, design options and installation procedures. In addition, a 35 ton prototype is already operational at Fermilab and will take data with single-phase detector in early 2016. After the prototyping phase, the multi-kton detector will be constructed. After commissioning, it will detect and study ne...

  7. A polybenzimidazole/ionic-liquid-graphite-oxide composite membrane for high temperature polymer electrolyte membrane fuel cells

    Science.gov (United States)

    Xu, Chenxi; Liu, Xiaoteng; Cheng, Jigui; Scott, Keith

    2015-01-01

    Graphite oxide is successfully functionalised by 3-aminopropyltriethoxysilane ionic liquid and used as a filler material in a polybenzimidazole (PBI) membrane for high temperature proton exchange membrane fuel cells. The ionic-liquid-graphite-oxide/polybenzimidazole (ILGO/PBI) composite membrane exhibits an appropriate level of proton conductivity when imbibed with phosphoric acid at low phosphoric acid loading, which promotes its use in fuel cells by avoiding acid leakage and materials corrosion. The ionic conductivities of the ILGO/PBI membranes at 175 °C are 0.035 S cm-1 and 0.025 S cm-1 at per repeat units of 3.5 and 2.0, respectively. The fuel cell performance of ILGO/PBI membranes exhibits a maximum power density of 320 mW cm-2 at 175 °C, which is higher than that of a pristine PBI membrane.

  8. Wetting of bulk metallic glass forming liquids on metals and ceramics

    Science.gov (United States)

    Ding, Shiyan; Kong, Jian; Schroers, Jan

    2011-08-01

    Contact wetting angle of Pd43Ni10Cu27P20, Pt57.5Cu14.7Ni5.3P22.5, Au49Ag5.5Pd2.3Cu26.9Si16.3, and Zr57Nb5Cu15.4Ni12.6Al10 bulk metallic glass forming alloys have been determined on materials that are used in micro and nano fabrication. Employing the sessile drop technique at a temperature above the corresponding melting temperatures, three kinds of wetting behaviors are observed, spanning from θ ≈ 140°, over neutral wetting, θ ≈ 80°, to almost complete wetting, θ < 5°. The origin for complete wetting is the formation of an interface phase promoting wetting. Estimations of the contact wetting angles are presented for temperatures in the supercooled liquid region where micro and nano fabrication is typically carried out. Consequences of the observed wetting behaviors for nanoforming are discussed.

  9. A SAXS study on nanostructure evolution in water free membranes containing ionic liquid: from dry membrane to saturation.

    Science.gov (United States)

    Sekhon, Satpal Singh; Park, Jin-Soo; Choi, Young-Woo

    2010-11-07

    Small-angle X-ray scattering (SAXS) technique has been used to study the evolution of ionomer peak in the recast Nafion membranes containing the ionic liquid 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIBF(4)). To the best of our knowledge, this is the first report dealing with the study of membranes containing different concentrations of the ionic liquid (EMIBF(4)), from the dry (no ionic liquid) to the saturation (containing 70 wt% ionic liquid) state to understand the evolution of the ionomer peak and the formation of ionic aggregates in these anhydrous membranes. The small-angle scattering maximum (ionomer peak) has been observed to shift continuously toward lower scattering vector (q) values as the ionic liquid content increases. The ionic conductivity behavior for the membranes containing ionic liquid has been found to be closely related with the change of slope of the double logarithmic plot between the reciprocal of the position of the ionomer peak and the polymer weight fraction. The q region over which Porod's law has been obeyed in different membranes was initially narrow and has been observed to widen with an increase in the content of the ionic liquid.

  10. Physically Gelled Room-Temperature Ionic Liquid-Based Composite Membranes for CO2/N-2 Separation: Effect of Composition and Thickness on Membrane Properties and Performance

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, PT; Voss, BA; Wiesenauer, EF; Gin, DL; Nobe, RD

    2013-07-03

    An aspartame-based, low molecular-weight organic gelator (LMOG) was used to form melt-infused and composite membranes with two different imidazolium-based room-temperature ionic liquids (RTILs) for CO2 separation from N-2. Previous work demonstrated that LMOGs can gel RTILs at low, loading levels, and this aspartame-based LMOG was selected because it has been reported to gel a large number of RTILs. The imidazolium-based RTILs were used because of their inherent good properties for CO2/light gas separations. Analysis of the resulting bulk RTIL/LMOG physical gels showed that these materials have high sol-gel transition temperatures (ca. 135 degrees C) suitable for flue gas applications. Gas permeabilities and burst pressure measurements of thick, melt infused membranes revealed a trade-off between high CO2 permeabilities and good mechanical stability as a function of the LMOG loading. Defect-free, composite membranes of the gelled RTILs were successfully fabricated by choosing an appropriate porous membrane support (hydrophobic PTFE) using a suitable coating technique (roller coating). The thicknesses of the applied composite gel layers ranged from 10.3 to 20.7 mu m, which represents an order of magnitude decrease in active layer thickness, compared to the original melt-infused gel RTIL membranes.

  11. 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.

  12. Thinning of reverse osmosis membranes by ionic liquids

    Science.gov (United States)

    Meng, Hong; Gong, Beibei; Geng, Tao; Li, Chunxi

    2014-02-01

    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.

  13. Removal of phenols from aqueous solutions by emulsion liquid membranes.

    Science.gov (United States)

    Reis, M Teresa A; Freitas, Ondina M F; Agarwal, Shiva; Ferreira, Licínio M; Ismael, M Rosinda C; Machado, Remígio; Carvalho, Jorge M R

    2011-09-15

    The present study deals with the extraction of phenols from aqueous solutions by using the emulsion liquid membranes technique. Besides phenol, two derivatives of phenol, i.e., tyrosol (2-(4-hydroxyphenyl)ethanol) and p-coumaric acid (4-hydroxycinnamic acid), which are typical components of the effluents produced in olive oil plants, were selected as the target solutes. The effect of the composition of the organic phase on the removal of solutes was examined. The influence of pH of feed phase on the extraction of tyrosol and p-coumaric was tested for the membrane with Cyanex 923 as an extractant. The use of 2% Cyanex 923 allowed obtaining a very high extraction of phenols (97-99%) in 5-6 min of contact time for either single solute solutions or for their mixtures. The removal efficiency of phenol and p-coumaric acid attained equivalent values by using the system with 2% isodecanol, but the removal rate of tyrosol was found greatly reduced. The extraction of tyrosol and p-coumaric acid from their binary mixture was also analysed for different operating conditions like the volume ratio of feed phase to stripping phase (sodium hydroxide), the temperature and the initial concentration of solute in the feed phase.

  14. Targeting proteins to liquid-ordered domains in lipid membranes.

    Science.gov (United States)

    Stachowiak, Jeanne C; Hayden, Carl C; Sanchez, Mari Angelica A; Wang, Julia; Bunker, Bruce C; Voigt, James A; Sasaki, Darryl Y

    2011-02-15

    We demonstrate the construction of novel protein-lipid assemblies through the design of a lipid-like molecule, DPIDA, endowed with tail-driven affinity for specific lipid membrane phases and head-driven affinity for specific proteins. In studies performed on giant unilamellar vesicles (GUVs) with varying mole fractions of dipalymitoylphosphatidylcholine (DPPC), cholesterol, and diphytanoylphosphatidyl choline (DPhPC), DPIDA selectively partitioned into the more ordered phases, either solid or liquid-ordered (L(o)) depending on membrane composition. Fluorescence imaging established the phase behavior of the resulting quaternary lipid system. Fluorescence correlation spectroscopy confirmed the fluidity of the L(o) phase containing DPIDA. In the presence of CuCl(2), the iminodiacetic acid (IDA) headgroup of DPIDA forms the Cu(II)-IDA complex that exhibits a high affinity for histidine residues. His-tagged proteins were bound specifically to domains enriched in DPIDA, demonstrating the capacity to target protein binding selectively to both solid and L(o) phases. Steric pressure from the crowding of surface-bound proteins transformed the domains into tubules with persistence lengths that depended on the phase state of the lipid domains.

  15. Bilayer membrane permeability of ionic liquid-filled block copolymer vesicles in aqueous solution.

    Science.gov (United States)

    Bai, Zhifeng; Zhao, Bin; Lodge, Timothy P

    2012-07-19

    The bilayer membrane permeability of block copolymer vesicles ("polymersomes") with ionic liquid interiors dispersed in water is quantified using fluorescence quenching. Poly((1,2-butadiene)-b-ethylene oxide) (PB-PEO) block copolymer vesicles in water with their interiors filled with a common hydrophobic ionic liquid, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide, were prepared containing a hydrophobic dye, Nile Red, by intact migration of dye-encapsulated vesicles from the ionic liquid to water at room temperature. A small quencher molecule, dichloroacetamide, was added to the aqueous solution of the dye-loaded vesicles, and the permeation of the quencher passing through the membrane into the interior was determined from the fluorescence quenching kinetics. Rapid permeation of the quencher across the nanoscale membrane was observed, consistent with the high fluidity of the liquid polybutadiene membrane. Two different PB-PEO copolymers were employed, in order to vary the thickness of the solvophobic membrane. A significant increase in membrane permeability was also observed with decreasing membrane thickness, which is tentatively attributable to differences in quencher solubility in the membranes. Quantitative migration of the vesicles from the aqueous phase back to an ionic liquid phase was achieved upon heating. These microscopically heterogeneous and thermoresponsive vesicles with permeable and robust membranes have potential as recyclable nanoreactors, in which the high viscosity and capital expense of an ionic liquid reaction medium can be mitigated, while retaining the desirable features of ionic liquids as reaction media, and facile catalyst recovery.

  16. Liquid general anesthetics lower critical temperatures in plasma membrane vesicles

    CERN Document Server

    Gray, Ellyn; Machta, Benjamin B; Veatch, Sarah L

    2013-01-01

    A large and diverse array of small hydrophobic molecules induce general anesthesia. Their efficacy as anesthetics has been shown to correlate both with their affinity for a hydrophobic environment and with their potency in inhibiting certain ligand gated ion channels. Here we explore the effects that n-alcohols and other liquid anesthetics have on the two-dimensional miscibility critical point observed in cell derived giant plasma membrane vesicles (GPMVs). We show that anesthetics depress the critical temperature (Tc) of these GPMVs without strongly altering the ratio of the two liquid phases found below Tc. The magnitude of this affect is consistent across n-alcohols when their concentration is rescaled by the median anesthetic concentration (AC50) for tadpole anesthesia, but not when plotted against the overall concentration in solution. At AC50 we see a 4{\\deg}C downward shift in Tc, much larger than is typically seen in the main chain transition at these anesthetic concentrations. GPMV miscibility critic...

  17. A study of chemical modifications of a Nafion membrane by incorporation of different room temperature ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Martinez de Yuso, M.V.; Rodriguez-Castellon, E. [Departamento de Quimica Inorganica, Facultad de Ciencias, Universidad de Malaga (Spain); Neves, L.A.; Coelhoso, I.M.; Crespo, J.G. [REQUIMTE/CQFB, Departamento de Quimica, Universidade Nova de Lisboa, Caparica (Portugal); Benavente, J. [Departamento de Fisica Aplicada I, Facultad de Ciencias, Universidad de Malaga (Spain)

    2012-08-15

    Surface and bulk chemical changes in a Nafion membrane as a result of room temperature ionic liquids (RTILs) incorporation were determined by X-ray photoelectron spectroscopy (XPS) and elemental analysis, respectively. RTILs with different physicochemical properties were selected. Two imidazolium based RTIL-cations (1-octyl-3-methylimidazolium and 1-butyl-3-methylimidazolium) were used to detect the effect of cation size on membrane modification, while the effect of the RTIL hydrophilic/hydrophobic character was also considered by choosing different anions. Angle resolved XPS measurements (ARXPS) were carried out varying the angle of analysis between 15 and 75 to get elemental information on the Nafion/RTIL-modified membranes interactions for a deepness of around 10 nm. Moreover, changes in the RTIL-modified membranes associated to thermal effect were also considered by analyzing the samples after their heating at 120 C for 24 h. Agreement between both chemical techniques, bulk and destructive elemental analysis and surface and non-destructive XPS, were obtained. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

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

    KAUST Repository

    Karunakaran, M.

    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.

  19. Transport of yttrium metal ions through fibers supported liquid membrane solvent extraction

    Institute of Scientific and Technical Information of China (English)

    A.G.Gaikwad; A.M.Rajput

    2010-01-01

    A novel idea of transport of yttrium(Ⅲ) metal ions through fibers supported liquid membrane in two stage processes namely source to membrane and membrane to receiving phase has been proposed.The fibers supported liquid membrane was impregnated with different concentrations carrier.The experimental variables explored were concentration of yttrium(Ⅲ) ions,pH of source phase,PC-88A concentration in membrane phase,acid concentration in receiving phase and stirring speed.The pre-concentration of yttrium(Ⅲ) ions ...

  20. 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.

  1. Development and Characterization of Polysulfone/Polyvinylidene Flouride Blend Membrane Induced by Delayed Liquid-Liquid Demixing

    Directory of Open Access Journals (Sweden)

    Ruwanti Dewi Cahya Ningrum

    2016-10-01

    Full Text Available Polysulfone (PSf-Polyvinylidene fluoride (PVDF membranes were fabricated via phase inversion method and immersion precipitation technique. In particular, the effect of varied amount of NMP addition into coagulation bath on permeability, mechanical properties, chemical resistance and thermal stability of membranes were investigated. The presence of solvent in coagulation bath caused delayed liquid-liquid demixing that caused increasing chance of disoriented interactions in PSf/PVDF blend membrane thus larger pore and dominated macrovoids membranes resulted. It was found that the increase of solvent addition lead to increasing of flux and decreasing of mechanical strength whereas a remarkably and enhanced chemical resistance has been achieved which showed excellent resistance in H2SO4 but degraded upon exposure to a concentration of 15% NaOH solution. Furthermore, TGA analysis revealed that the membrane exhibit improved thermal stability while the morphology of membrane showed the formation of asymmetry structure.

  2. Simultaneous probing of bulk liquid phase and catalytic gas-liquid-solid interface under working conditions using attenuated total reflection infrared spectroscopy

    Science.gov (United States)

    Meemken, Fabian; Müller, Philipp; Hungerbühler, Konrad; Baiker, Alfons

    2014-08-01

    Design and performance of a reactor set-up for attenuated total reflection infrared (ATR-IR) spectroscopy suitable for simultaneous reaction monitoring of bulk liquid and catalytic solid-liquid-gas interfaces under working conditions are presented. As advancement of in situ spectroscopy an operando methodology for gas-liquid-solid reaction monitoring was developed that simultaneously combines catalytic activity and molecular level detection at the catalytically active site of the same sample. Semi-batch reactor conditions are achieved with the analytical set-up by implementing the ATR-IR flow-through cell in a recycle reactor system and integrating a specifically designed gas feeding system coupled with a bubble trap. By the use of only one spectrometer the design of the new ATR-IR reactor cell allows for simultaneous detection of the bulk liquid and the catalytic interface during the working reaction. Holding two internal reflection elements (IRE) the sample compartments of the horizontally movable cell are consecutively flushed with reaction solution and pneumatically actuated, rapid switching of the cell (<1 s) enables to quasi simultaneously follow the heterogeneously catalysed reaction at the catalytic interface on a catalyst-coated IRE and in the bulk liquid on a blank IRE. For a complex heterogeneous reaction, the asymmetric hydrogenation of 2,2,2-trifluoroacetophenone on chirally modified Pt catalyst the elucidation of catalytic activity/enantioselectivity coupled with simultaneous monitoring of the catalytic solid-liquid-gas interface is shown. Both catalytic activity and enantioselectivity are strongly dependent on the experimental conditions. The opportunity to gain improved understanding by coupling measurements of catalytic performance and spectroscopic detection is presented. In addition, the applicability of modulation excitation spectroscopy and phase-sensitive detection are demonstrated.

  3. Simultaneous probing of bulk liquid phase and catalytic gas-liquid-solid interface under working conditions using attenuated total reflection infrared spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Meemken, Fabian; Müller, Philipp; Hungerbühler, Konrad; Baiker, Alfons, E-mail: baiker@chem.ethz.ch [Department of Chemistry and Applied Biosciences, Institute for Chemical and Bioengineering, ETH Zürich, Hönggerberg, HCI, CH-8093 Zürich (Switzerland)

    2014-08-15

    Design and performance of a reactor set-up for attenuated total reflection infrared (ATR-IR) spectroscopy suitable for simultaneous reaction monitoring of bulk liquid and catalytic solid-liquid-gas interfaces under working conditions are presented. As advancement of in situ spectroscopy an operando methodology for gas-liquid-solid reaction monitoring was developed that simultaneously combines catalytic activity and molecular level detection at the catalytically active site of the same sample. Semi-batch reactor conditions are achieved with the analytical set-up by implementing the ATR-IR flow-through cell in a recycle reactor system and integrating a specifically designed gas feeding system coupled with a bubble trap. By the use of only one spectrometer the design of the new ATR-IR reactor cell allows for simultaneous detection of the bulk liquid and the catalytic interface during the working reaction. Holding two internal reflection elements (IRE) the sample compartments of the horizontally movable cell are consecutively flushed with reaction solution and pneumatically actuated, rapid switching of the cell (<1 s) enables to quasi simultaneously follow the heterogeneously catalysed reaction at the catalytic interface on a catalyst-coated IRE and in the bulk liquid on a blank IRE. For a complex heterogeneous reaction, the asymmetric hydrogenation of 2,2,2-trifluoroacetophenone on chirally modified Pt catalyst the elucidation of catalytic activity/enantioselectivity coupled with simultaneous monitoring of the catalytic solid-liquid-gas interface is shown. Both catalytic activity and enantioselectivity are strongly dependent on the experimental conditions. The opportunity to gain improved understanding by coupling measurements of catalytic performance and spectroscopic detection is presented. In addition, the applicability of modulation excitation spectroscopy and phase-sensitive detection are demonstrated.

  4. Simultaneous probing of bulk liquid phase and catalytic gas-liquid-solid interface under working conditions using attenuated total reflection infrared spectroscopy.

    Science.gov (United States)

    Meemken, Fabian; Müller, Philipp; Hungerbühler, Konrad; Baiker, Alfons

    2014-08-01

    Design and performance of a reactor set-up for attenuated total reflection infrared (ATR-IR) spectroscopy suitable for simultaneous reaction monitoring of bulk liquid and catalytic solid-liquid-gas interfaces under working conditions are presented. As advancement of in situ spectroscopy an operando methodology for gas-liquid-solid reaction monitoring was developed that simultaneously combines catalytic activity and molecular level detection at the catalytically active site of the same sample. Semi-batch reactor conditions are achieved with the analytical set-up by implementing the ATR-IR flow-through cell in a recycle reactor system and integrating a specifically designed gas feeding system coupled with a bubble trap. By the use of only one spectrometer the design of the new ATR-IR reactor cell allows for simultaneous detection of the bulk liquid and the catalytic interface during the working reaction. Holding two internal reflection elements (IRE) the sample compartments of the horizontally movable cell are consecutively flushed with reaction solution and pneumatically actuated, rapid switching of the cell (interface on a catalyst-coated IRE and in the bulk liquid on a blank IRE. For a complex heterogeneous reaction, the asymmetric hydrogenation of 2,2,2-trifluoroacetophenone on chirally modified Pt catalyst the elucidation of catalytic activity/enantioselectivity coupled with simultaneous monitoring of the catalytic solid-liquid-gas interface is shown. Both catalytic activity and enantioselectivity are strongly dependent on the experimental conditions. The opportunity to gain improved understanding by coupling measurements of catalytic performance and spectroscopic detection is presented. In addition, the applicability of modulation excitation spectroscopy and phase-sensitive detection are demonstrated.

  5. Cellulose triacetate doped with ionic liquids for membrane gas separation

    Science.gov (United States)

    Lam, Benjamin Fatt Soon

    The doping of cellulose triacetate (CTA) with imidazolium based ionic liquids (ILs) is investigated in order to reduce the polymer crystallinity and enhance the affinity with CO2, thus increasing CO2 permeability and CO2/light gas selectivity. CTA membranes doped with [emim] BF4 or [emim] DCA were prepared, and the effect of the ILs loading on properties, such as crystallinity, density, degradation temperature, glass transition temperature, and gas transport properties, has been determined. In general, doping with IL reduces the crystallinity in CTA, increasing gas solubility, diffusivity and permeability. The ILs doping also increases CO 2/CH4 solubility selectivity and CO2/N2 permeability selectivity, due to the affinity of these ILs with CO2, instead of light gases such as CH4 and N2. This study provides a mechanistic understanding of interaction of ILs and CTA, and demonstrates an effective route in manipulating the morphology and gas transport properties of semi crystalline polymers by doping with ILs.

  6. Interfacial interactions in aprotic ionic liquid based protonic membrane and its correlation with high temperature conductivity and thermal properties.

    Science.gov (United States)

    Mistry, Mayur K; Subianto, Surya; Choudhury, Namita Roy; Dutta, Naba K

    2009-08-18

    Novel supported liquid membranes (SLMs) have been developed by impregnating Nafion and Hyflon membranes with ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (BMI-BTSI). These supported liquid membranes were characterized in terms of their ionic liquid uptake behavior, leaching of ionic liquid by water, thermal stability, mechanical properties, glass transition temperature, ion exchange capacity, and proton conductivity. In general, modified membranes are more flexible than unmodified samples due to the plasticization effects of the ionic liquid. However, these supported liquid membranes exhibit a significant increase in their operational stability and proton conductivity over unmodified membranes. We also demonstrate that proton conductivity of these supported liquid membranes allows conduction of protons in anhydrous conditions with conductivity increasing with temperature. Conductivity of up to 3.58 mS cm(-1) has been achieved at 160 degrees C in dry conditions, making these materials promising for various electrochemical applications.

  7. Sensing characteristics of pure-shear film bulk acoustic resonator in viscous liquids

    Science.gov (United States)

    Chen, Da; Song, Shuren; Zhang, Dexue; Wang, Peng; Liu, Weihui

    2017-03-01

    We presented a pure-shear film bulk acoustic resonator (FBAR) and investigated its sensing characteristics in viscous liquids. In the resonator, the electrodes were located on the surface of c-axis-oriented AlN film to generate the lateral electric field and excite the shear acoustic resonance. Compared with the typical quasi-shear film bulk acoustic resonator based on inclined c-axis-oriented AlN or ZnO piezoelectric film, the proposed device exhibits significantly higher Q-factors and a notably improved detection limit, particularly in water and viscous liquids. The frequency shifts show a linear dependency on the square root of the product of the liquid viscosity and density of the glycerol solution in the viscosity range of 1-5 mPaṡs. Furthermore, we measured the mass sensitivity through real-time monitoring of the frequency change during the volatilization process of the loaded saline solutions. The proposed device shows the mass sensitivity of 465 Hzṡcm2/ng and the mass resolutions of 0.17 ng/cm2 in air, 0.25 ng/cm2 in water and 2.08 ng/cm2 in 50% glycerol solution, respectively. The obtained results clearly indicate that the proposed device is capable of using in liquid phase detection with high sensitivity requirements.

  8. 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)

  9. Preparation of Calcium Carbonate Nanoparticles with a Continuous Gas-liquid Membrane Contactor:Particles Morphology and Membrane Fouling

    Institute of Scientific and Technical Information of China (English)

    JIA Zhiqian; CHANG Qing; QIN Jin; MAMAT Aynur

    2013-01-01

    Nanosized calcium carbonate particles were prepared with a continuous gas-liquid membrane contactor.The effects of Ca(OH)2 concentration,CO2 pressure and liquid flow velocity on the particles morphology,pressure drop and membrane fouling were studied.With rising Ca(OH)2 concentrations,the average size of the particles increased.The effects of Ca(OH)2 concentration and CO2 pressure on particles were not apparent under the experimental conditions.When the Ca(OH)2 concentration and liquid flow velocity were high,or the CO2 pressure was low,the fouling on the membrane external surface at the contactor entrance was serious due to liquid leakage,whereas the fouling was slight at exit.The fouling on the membrane inner-surface at entrance was apparent due to adsorption of raw materials.The membrane can be recovered by washing with dilute hydrochloric acid and reused for at least 6 times without performance deterioration.

  10. Molar volume, thermal expansion, and bulk modulus in liquid Fe-Ni alloys at 1 bar: Evidence for magnetic anomalies?

    Science.gov (United States)

    Nasch, P. M.; Manghnani, M. H.

    New experimental data on the molar volume Ω, thermal expansion coefficient α, and ultrasonic sound velocity vp in liquid Fe-Ni systems at temperatures between melting and 1975 K are reported. The molar volume and thermal expansion data were acquired using a penetrating γ radiation method; the sound velocity data were obtained by ultrasonic interferometry. In the temperature range of this study, the molar volume Ω increases and the sound velocity vp decreases, both linearly with temperature. The adiabatic bulk modulus KS ∝ v2p/Ωp of liquid Fe-Ni alloys is nearly independent of composition at Fe content greater than 65 wt%. The temperature derivative ∂K/∂T of both adiabatic and isothermal bulk modulus of pure liquid Fe decreases by approximately 50% upon being alloyed with 15 wt% Ni. The mixing behavior of thermodynamic and cohesive properties of liquid Fe-Ni is interpreted as resulting from the existence of disordered and localized magnetic states and correlations in the liquid state, i.e., well above the Curie temperature and extending from pure Fe into the Fe-Ni stability field. These magnetic contributions have strong mechanical effects on the structure in modifying the volume and elastic modulus by as much as 13% and 31%, respectively, in the case of pure liquid Fe. It is believed that the magnetic contribution, which is likely to be absent at core temperatures, should be removed from the measured 1-bar values of density and elastic moduli if these latter were to be used as precise anchoring points in high pressure-temperature EOS.

  11. Enhanced Membrane System for Recovery of Water from Gas-Liquid Mixtures Project

    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...

  12. Supported ionic liquid membranes for removal of dioxins from high-temperature vapor streams.

    Science.gov (United States)

    Kulkarni, Prashant S; Neves, Luisa A; Coelhoso, Isabel M; Afonso, Carlos A M; Crespo, João G

    2012-01-03

    Dioxins and dioxin-like chemicals are predominantly produced by thermal processes such as incineration and combustion at concentrations in the range of 10-100 ng of I-TEQ/kg (I-TEQ = international toxic equivalents). In this work, a new approach for the removal of dioxins from high-temperature vapor streams using facilitated supported ionic liquid membranes (SILMs) is proposed. The use of ceramic membranes containing specific ionic liquids, with extremely low volatility, for dioxin removal from incineration sources is proposed owing to their stability at very high temperatures. Supported liquid membranes were prepared by successfully immobilizing the ionic liquids tri-C(8)-C(10)-alkylmethylammonium dicyanamide ([Aliquat][DCA]) and 1-n-octyl-3-methylimidazolium dicyanamide ([Omim][DCA]) inside the porous structure of ceramic membranes. The porous inorganic membranes tested were made of titanium oxide (TiO(2)), with a nominal pore size of 30 nm, and aluminum oxide (Al(2)O(3)), with a nominal pore size of 100 nm. The ionic liquids were characterized, and the membrane performance was assessed for the removal of dioxins. Different materials (membrane pore size, type of ionic liquid, and dioxin) and different operating conditions (temperature and flow rate) were tested to evaluate the efficiency of SILMs for dioxin removal. All membranes prepared were stable at temperatures up to 200 °C. Experiments with model incineration gas were also carried out, and the results obtained validate the potential of using ceramic membranes with immobilized ionic liquids for the removal of dioxins from high-temperature vapor sources.

  13. Supported liquid membrane stability in chiral resolution by chemically and physically modified membranes

    Energy Technology Data Exchange (ETDEWEB)

    Molinari, R.; Argurio, P. [Arcavata di Rende Univ. of Calabria, Arcavata di Rende, CS (Italy). Dept. of Chemical and Materials Engineering

    2001-04-01

    In the present work some stability studies on Supported Liquid Membranes (SLMs) to be used for chiral separations were realized. In particular, primary aim was to determine how a modification of the support surface influences the SLM stability. First, the procedure for support modification was optimised, making a screening of various compounds (sulphuric acid, nitric acid, chromic acid, sodium dodecyl sulphate (SDS), glycerol, oleic alcohol, propylene glycol (PPG), bovine serum albumin (BSA)) and testing their performance by means of contact angle measurements. Next, a second screening was realized by permeation tests in a stirred cell. Finally, to compare the stability of modified with unmodified support in a process of interest for chemical and/or biochemical industries, some permeation tests for resolution of DNB-DL-Leucine were realized in a re-circulation system. Results showed a better surface hydrophilization of chemically modified support and better stability of the sulphonated support. However, in operating conditions a little high stability of the unmodified support was obtained. [Italian] Nel presente lavoro sono stati realizzati degli studi di stabilita' di Membrane Liquide Supportate (SLMs) da impiegare in separazioni chirali. In particolare, obiettivo principale e' stato quello di determinare l'influenza che una modifica della superficie del supporto ha sulla stabilita' della SLM. Cosi', in un primo momento, e' stata ottimizzata le procedura di modifica del supporto, facendo una selezione tra vari composti (acido solforico, acido nitrico, acido cromico, sodio dodecil solfato (SDS), glicerolo, alcool oleico, glicole propilenico (PPG), siero di albumina bovina (BSA)) basata su misure dell'angolo di contatto. Successivamente, e' stata realizzata una seconda selezione mediante prove di permeazione in una cella agitata. Infine, con lo scopo di confrontare la stabilita' della SLM con supporto modificato rispetto

  14. Applicability of a liquid membrane in enrichment and determination of nickel traces from natural waters

    Energy Technology Data Exchange (ETDEWEB)

    Dominguez-Lledo, F.C.; Diaz-Lopez, I.C. [University of Havana, Department of Analytical Chemistry, Faculty of Chemistry, Havana (Cuba); Galindo-Riano, Maria D.; Garcia-Vargas, M.; Granado-Castro, M.D. [University of Cadiz, Department of Analytical Chemistry, Faculty of Sciences, Cadiz (Spain)

    2007-09-15

    In this work, a bulk liquid membrane method has been applied for Ni enrichment and separation from natural waters. The carrier-mediated transport was accomplished by pyridine-2-acetaldehyde benzoylhydrazone dissolved in toluene as a complexing agent. The preconcentration was achieved through pH control of source and receiving solutions via a counterflow of protons. The main variables were optimized by using a modified simplex technique. High transport efficiencies (101.2 {+-} 1.8-99.7 {+-} 4.2%) were provided by the carrier for nickel ions in a receiving phase of 0.31 mol L{sup -1} nitric acid after 9-13 h depending on sample salinity. The precision of the method was 2.05% (without a saline matrix) and 4.04% (with 40 g L{sup -1} NaCl) at the 95% confidence level and the detection limit of the blank was 0.015 {mu}g L{sup -1} Ni for detection by atomic absorption spectroscopy. The applicability of the method was tested on certified reference and real water samples with successful results, even for saline samples. The relative errors were -0.60% for certified reference materials and ranged from -0.39 to 2.90% and from 0.3 to 11.05% for real samples, obtained by comparison of inductively coupled plasma mass spectrometry and adsorptive cathodic stripping voltammetry measurements, respectively. (orig.)

  15. A computational formulation for constrained solid and liquid membranes considering isogeometric finite elements

    CERN Document Server

    Sauer, Roger A; Corbett, Callum J

    2012-01-01

    A geometrically exact membrane formulation is presented that is based on curvilinear coordinates and isogeometric finite elements, and is suitable for both solid and liquid membranes. The curvilinear coordinate system is used to describe both the theory and the finite element equations of the membrane. In the latter case this avoids the use of local cartesian coordinates at the element level. Consequently, no transformation of derivatives is required. The formulation considers a split of the in-plane and out-of-plane membrane contributions, which allows the construction of a stable formulation for liquid membranes with constant surface tension. The proposed membrane formulation is general, and accounts for dead and live loading, as well as enclosed volume, area, and contact constraints. The new formulation is illustrated by several challenging examples, considering linear and quadratic Lagrange elements, as well as isogeometric elements based on quadratic NURBS and cubic T-splines. It is seen that the isogeom...

  16. A variational approach to the liquid-vapor phase transition for hardcore ions in the bulk and in nanopores

    CERN Document Server

    Loubet, Bastien; Palmeri, John

    2016-01-01

    We employ a field-theoretical variational approach to study the behavior of ionic solutions in the grand canonical ensemble. To describe properly the hardcore interactions between ions, we use a cutoff in Fourier space for the electrostatic contribution of the grand potential and the Carnahan-Starling equation of state with a modified chemical potential for the pressure one. We first calibrate our method by comparing its predictions at room temperature with Monte Carlo results for excess chemical potential and energy. We then validate our approach in the bulk phase by describing the classical "ionic liquid-vapor" phase transition induced by ionic correlations at low temperature, before applying it to electrolytes at room temperature confined to nanopores embedded in a low dielectric medium and coupled to an external reservoir of ions. The ionic concentration in the nanopore is then correctly described from very low bulk concentrations, where dielectric exclusion shifts the transition up to room temperature fo...

  17. Hollow-fiber-supported liquid membranes with improved stability for nitrate removal

    NARCIS (Netherlands)

    Kemperman, A.J.B.; Rolevink, H.H.M.; Boomgaard, van den Th.; Strathmann, H.

    1997-01-01

    This paper describes the development of a hollow-fiber-supported liquid membrane (HFSLM) for the removal of nitrate ions from water. Two different membrane modules were designed which differed in length of the fibers. In order to test the HFSLMs on nitrate flux and stability, two set-ups were used:

  18. Pore formation by antimicrobial peptides: structural tendencies in bulk and quasi-2D membrane systems

    Science.gov (United States)

    Gordon, Vernita; Yang, Lihua; Davis, Matthew; Som, A.; Tew, G.; Wong, Gerard

    2007-03-01

    Antimicrobial peptides are cationic, amphiphilic structures that are key components of innate immunity. A prototypical family of synthetic analogs are the phenylene ethynylene antimicrobial oligomers (AMOs), which have hydrophobic alkyl chains connected to cationic hydrophilic regions. Synchrotron small-angle x-ray scattering (SAXS) shows that when AMO is mixed with concentrated model membranes, initially in the form of Small Unilamellar Vesicles, the sample forms the inverted hexagonal phase. This is a 3-dimensional phase characterized by a regular array of size-defined water channels. We demonstrate how this structural tendency is expressed when AMOs interact with dilute model membranes in the form of Giant Unilamellar Vesicles (GUVs). Using confocal microscopy, we see that applying AMO to the GUVs causes small encapsulated molecules to be released while large molecules are retained, indicating that size-defined pores have been created. Examining the partial release of polydisperse intermediately-sized molecules allows a closer measurement of the pore size, and there are indications that this single-vesicle microscopy will allow elucidation of the kinetics of the pore-forming process.

  19. Constructing CO2-facilitated transport highway in supported ionic liquid membranes

    Science.gov (United States)

    Sun, Xiang Jun; Luo, Ju Jie; Zhang, Meng; Li, Jin Ping

    2014-01-01

    A Carbon dioxide-facilitated transport highway (CO2-FTH) on the microporous surface of a membrane matrix was designed using the amino carrier 3-aminopropyltriethoxysilane (APTES). Owing to the reversible reaction between CO2 molecules and fixed-site carriers, this supported ionic liquid membrane was able to selectively transfer CO2 more quickly. This concept may inspire means of fabricating a highly permeable and selective membrane to break through Robeson's upper bound.

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

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, J.D.

    1994-08-04

    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.

  1. Cholinium-based supported ionic liquid membranes: a sustainable route for carbon dioxide separation.

    Science.gov (United States)

    Tomé, Liliana C; Patinha, David J S; Ferreira, Rui; Garcia, Helga; Silva Pereira, Cristina; Freire, Carmen S R; Rebelo, Luís Paulo N; Marrucho, Isabel M

    2014-01-01

    Aiming at full sustainability of CO2 separation processes, a series of supported ionic liquid membranes based on environmentally friendly cholinium carboxylate ionic liquids were successfully prepared. Their gas permeation properties were measured and high permselectivities were obtained for both CO2 /CH4 and CO2 /N2 .

  2. Isoconfigurational elastic constants and liquid fragility of a bulk metallic glass forming alloy.

    Science.gov (United States)

    Lind, Mary Laura; Duan, Gang; Johnson, William L

    2006-07-07

    Samples of Zr(46.25)Ti(8.25)Cu(7.5)Ni(10)Be(27.5) were isothermally annealed and quenched near the glass transition temperature and studied by the pulse-echo overlap technique. The shear modulus G of the samples shows a strong reversible dependence on annealing temperatures and, thus, on the specific configurational potential energy of the equilibrium liquid. The low-T dependence of G of the configurationally frozen glasses shows linear temperature dependence as expected by Debye-Grüneisen theory. The T dependence of G in the liquid state is directly related to the viscosity and fragility of the liquid.

  3. 77 FR 14327 - Bulk Packaging To Allow for Transfer of Hazardous Liquid Cargoes

    Science.gov (United States)

    2012-03-09

    ... FR Federal Register HMR Hazardous Materials Regulations; 49 CFR Parts 171-180 IBC Intermediate Bulk... Materials by Vessel'' (55 FR 37406), the Coast Guard allowed the use of Intermodal (IM) 101 and IM 102... describe the types of IBCs the Coast Guard would allow for the carriage of certain hazardous materials...

  4. 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...... was promoted by a carrier dissolved in the membrane, creating a temporary ion-pair complex between the hydrophilic drug and the carrier. As the model analytes were extracted directly into an aqueous solution, there was no need for evaporation of the extract before injection into LC-MS. Hence, the sample...

  5. Collective dynamics of water in the living cell and in bulk liquid. New physical models and biologcial infereneces

    CERN Document Server

    Preoteasa, Eugen A

    2008-01-01

    In the frame of collective dynamics in water, models built on elementary excitations and long-range electromagnetic interactions in the cell and bulk liquid are presented. Making use of the low effective mass of water coherence domains (CDs), we examined the relevance of simple quantum models to cellular characteristics. A hypothesis of CDs Bose-type condensation, and models of CD in spherical wells with impenetrable and semipenetrable walls, and of an isotropic oscillator consisting of two interacting CDs were investigated. Estimated cellular volumes matched to medium-sized bacteria and small prokaryotes, and to some organelles in eukaryotic cells. Also, the cytotoxic effects of heavy water in eukaryotes were explained. In another approach we proposed a plasmon-like model of hydrogen-oxygen ionic plasma in liquid water. In addition to plasmonic oscillations, the model predicted sound-like non-equilibrium elementary excitations that we called densitons (the sound anomaly of water), the vaporization heat and t...

  6. 40 CFR 265.314 - Special requirements for bulk and containerized liquids.

    Science.gov (United States)

    2010-07-01

    ... Determining Resistance of Plastics to Bacteria; or (iii) The sorbent material is determined to be non-biodegradable under OECD test 301B: . (f) The placement of any liquid which is not a hazardous waste in...

  7. Facilitated oxygen transport in liquid membranes: review and new concepts

    NARCIS (Netherlands)

    Figoli, A.; Sager, W.F.C.; Mulder, M.H.V.

    2001-01-01

    In this paper, an overview is given on membranes with oxygen facilitated transport properties to enrich the oxygen content in air. Special emphasis is paid to recent developments of oxygen carrier systems and carrier containing membranes. Concepts leading to a structural evolution of supported liqui

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

    KAUST Repository

    Bettahalli, N.M. 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.

  9. 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.

  10. Reverse osmosis molecular differentiation of organic liquids using carbon molecular sieve membranes

    Science.gov (United States)

    Koh, Dong-Yeun; McCool, Benjamin A.; Deckman, Harry W.; Lively, Ryan P.

    2016-08-01

    Liquid-phase separations of similarly sized organic molecules using membranes is a major challenge for energy-intensive industrial separation processes. We created free-standing carbon molecular sieve membranes that translate the advantages of reverse osmosis for aqueous separations to the separation of organic liquids. Polymer precursors were cross-linked with a one-pot technique that protected the porous morphology of the membranes from thermally induced structural rearrangement during carbonization. Permeation studies using benzene derivatives whose kinetic diameters differ by less than an angstrom show kinetically selective organic liquid reverse osmosis. Ratios of single-component fluxes for para- and ortho-xylene exceeding 25 were observed and para- and ortho- liquid mixtures were efficiently separated, with an equimolar feed enriched to 81 mole % para-xylene, without phase change and at ambient temperature.

  11. Halogen-free ionic liquid as an additive in zinc(II)-selective electrode: surface analyses as correlated to the membrane activity.

    Science.gov (United States)

    Al-Asousi, Maryam F; Shoukry, Adel F; Bu-Olayan, Abdul Hadi

    2012-05-30

    Two conventional Zn(II) polyvinyl chloride (PVC) membrane electrodes have been prepared and characterized. They were based on dibenzo-24-crown-8 (DBC) as a neutral carrier, dioctyl phthalate (DOP) as a plasticizer, and potassium tetrakis (p-chlorophenyl) borate, KTpClPB or the halogen-free ionic liquid, tetraoctylammonium dodecylbenzene sulfonate [TOA][DBS] as an additive. The use of ionic liquid has been found to enhance the selectivity of the sensor. For each electrode, the surfaces of two membranes were investigated using X-ray photoelectron, ion-scattering spectroscopy and atomic force microscopy. One of the two membranes was conditioned by soaking it for 24 h in a 1.0×10(-3) M Zn(NO(3))(2) solution and the second was soaked in bi-distilled water for the same interval (24 h). Comparing the two surfaces indicated the following: (a) the high selectivity in case of using [TOA][DBS] as an additive is due to the extra mediation caused by the ionic liquid and (b) the working mechanism of the electrode is based on phase equilibrium at the surface of the membrane associated with ion transport through the bulk of the membrane.

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

    Science.gov (United States)

    Couto, Ricardo; Neves, Luísa; Simões, Pedro; Coelhoso, Isabel

    2015-01-14

    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.

  13. 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.

  14. 49 CFR 173.244 - Bulk packaging for certain pyrophoric liquids (Division 4.2), dangerous when wet (Division 4.3...

    Science.gov (United States)

    2010-10-01

    ... (Division 4.2), dangerous when wet (Division 4.3) materials, and poisonous liquids with inhalation hazards (Division 6.1). 173.244 Section 173.244 Transportation Other Regulations Relating to Transportation PIPELINE... Other Than Class 1 and Class 7 § 173.244 Bulk packaging for certain pyrophoric liquids (Division...

  15. Microporous hollow fibre membrane modules as gas-liquid contactors. Part 1: Physical mass transfer processes. A specific application: mass transfer in highly viscous liquids

    NARCIS (Netherlands)

    Kreulen, H.; Versteeg, G.F.; Smolders, C.A.; Swaaij, van W.P.M.

    1993-01-01

    Gas-liquid mass transfer has been studied in a membrane module with non-wetted microporous fibres in the laminar flow regime. This new type of gas/liquid contactor can be operated stabily over a large range of gas and liquid flows because gas and liquid phase do not influence each other directly. Th

  16. Deformation behavior of Zr-based bulk metallic glass and composite in the supercooled liquid region

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A Zr-based bulk metallic glass (BMG) with a composition of (Zr75Cu25)78.5Ta4Ni10Al7.5 and a bulk metallic glass matrix composite (BMGC) with a composition of (Zr75Cu25)74.5Ta8Ni10Al7.5 have been prepared by copper-mold casting. The compres-sive deformation behavior of the BMG and BMGC was investigated in the super-cooled region at different temperatures and various strain rates ranging from 8×10-4s-1 to 8×10-2s-1. It was found that both the strain rate and test temperature signifi-cantly affect the deformation behavior of the two alloys. The deformation follows Newtonian flow at low strain rates but non-Newtonian flow at high strain rates. The deformation mechanism for the two kinds of alloys was discussed in terms of the transition state theory.

  17. Liquid but Durable: Molecular Dynamics Simulations Explain the Unique Properties of Archaeal-Like Membranes

    Science.gov (United States)

    Chugunov, Anton O.; Volynsky, Pavel E.; Krylov, Nikolay A.; Boldyrev, Ivan A.; Efremov, Roman G.

    2014-12-01

    Archaeal plasma membranes appear to be extremely durable and almost impermeable to water and ions, in contrast to the membranes of Bacteria and Eucaryota. Additionally, they remain liquid within a temperature range of 0-100°C. These are the properties that have most likely determined the evolutionary fate of Archaea, and it may be possible for bionanotechnology to adopt these from nature. In this work, we use molecular dynamics simulations to assess at the atomistic level the structure and dynamics of a series of model archaeal membranes with lipids that have tetraether chemical nature and ``branched'' hydrophobic tails. We conclude that the branched structure defines dense packing and low water permeability of archaeal-like membranes, while at the same time ensuring a liquid-crystalline state, which is vital for living cells. This makes tetraether lipid systems promising in bionanotechnology and material science, namely for design of new and unique membrane nanosystems.

  18. Stability of a nanofiltration membrane after contact with a low-level liquid radioactive waste

    Directory of Open Access Journals (Sweden)

    Elizabeth Eugenio de Mello Oliveira

    2013-01-01

    Full Text Available This study investigated the treatment of a liquid radioactive waste containing uranium (235U + 238U using nanofiltration membranes. The membranes were immersed in the waste for 24-5000 h, and their transport properties were evaluated before and after the immersion. Surface of the membranes changed after immersion in the waste. The SW5000 h specimen lost its coating layer of polyvinyl alcohol, and its rejection of sulfate ions and uranium decreased by about 35% and 30%, respectively. After immersion in the waste, the polyamide selective layer of the membranes became less thermally stable than that before immersion.

  19. Segregation of ions at the interface: molecular dynamics studies of the bulk and liquid-vapor interface structure of equimolar binary mixtures of ionic liquids.

    Science.gov (United States)

    Palchowdhury, Sourav; Bhargava, B L

    2015-08-14

    The structures of three different equimolar binary ionic liquid mixtures and their liquid-vapor interface have been studied using atomistic molecular dynamics simulations. Two of these binary mixtures were composed of a common cation 1-n-butyl-3-methylimidazolium and varying anions (chloride and hexafluorophosphate in one of the mixtures and chloride and trifluoromethanesulfonate in the other) and the third binary mixture was composed of a common anion, trifluoromethanesulfonate and two imidazolium cations with ethyl and octyl side chains. Binary mixtures with common cations are found to be homogeneous. The anions are preferentially located near the ring hydrogen atoms due to H-bonding interactions. Segregation of ions is observed at the interface with an enrichment of the liquid-vapor interface layer by longer alkyl chains and bigger anions with a distributed charge. The surface composition is drastically different from that of the bulk composition, with the longer alkyl tail groups and bigger anions populating the outermost layer of the interface. The longer alkyl chains of the cations and trifluoromethanesulfonate anions with a smaller charge density show orientational ordering at the liquid-vapor interface.

  20. Permeability of Rubbery and Glassy Membranes of Ionic Liquid Filled Polymersome Nanoreactors in Water.

    Science.gov (United States)

    So, Soonyong; Yao, Letitia J; Lodge, Timothy P

    2015-12-03

    Nanoemulsion-like polymer vesicles (polymersomes) having ionic liquid interiors dispersed in water are attractive for nanoreactor applications. In a previous study, we demonstrated that small molecules could pass through rubbery polybutadiene membranes on a time scale of seconds, which is practical for chemical transformations. It is of interest to determine how sensitive the rate of transport is to temperature, particularly for membranes in the vicinity of the glass transition (Tg). In this work, the molecular exchange rate of 1-butylimidazole through glassy polystyrene (PS) bilayer membranes is investigated via pulsed field gradient nuclear magnetic resonance (PFG-NMR) over the temperature range from 25 to 70 °C. The vesicles were prepared by the cosolvent method in the ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide ([EMIM][TFSI]), and four different polystyrene-b-poly(ethylene oxide) (PS-PEO) diblock polymers with varying PS molecular weights were examined. The vesicles were transferred from the ionic liquid to water at room temperature to form nanoemulsion solutions of polymer vesicles in water. The exchange rate of 1-butylimidazole added to the aqueous solutions was observed under equilibrium conditions at each temperature. The exchange rate decreased as the membrane thickness increased, and the exchange rate through the glassy membranes was three to four times slower than through the rubbery polybutadiene membranes under the same experimental conditions. These results demonstrate that the permeability through nanosized membranes depends on both the dimension and chemistry of membrane-forming blocks. Furthermore, the exchange rate was investigated as a function of temperature in the vicinity of the Tg of PS-PEO membranes. The exchange rate, however, is not a strong function of the temperature in the vicinity of the membrane Tg, due to a combination of the nanoscopic dimension of the membrane, and some degree of solvent

  1. One-step extraction of polar drugs from plasma by parallel artificial liquid membrane extraction.

    Science.gov (United States)

    Pilařová, Veronika; Sultani, Mumtaz; Ask, Kristine Skoglund; Nováková, Lucie; Pedersen-Bjergaard, Stig; Gjelstad, Astrid

    2017-02-01

    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 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-throughput is achievable, in addition to the green chemistry offered by using PALME. The consumption of organic solvent is minimized to 3-5μL per sample. With a sample volume of 250μL and acceptor solution volume of 50μL, a maximal enrichment factor of five is achievable. Based on these parameters, a new method 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 was promoted by a carrier dissolved in the membrane, creating a temporary ion-pair complex between the hydrophilic drug and the carrier. As the model analytes were extracted directly into an aqueous solution, there was no need for evaporation of the extract before injection into LC-MS. Hence, the sample preparation is performed in one step. With optimized conditions, the extraction recoveries were in the range 50-89% from human plasma after 45min extraction. The data from the method evaluation were satisfactory and in line with current guidelines, and revealed an extraction method with substantial potential for high throughput bioanalysis of polar basic drugs.

  2. Experimentally probing the libration of interfacial water: the rotational potential of water is stiffer at the air/water interface than in bulk liquid.

    Science.gov (United States)

    Tong, Yujin; Kampfrath, Tobias; Campen, R Kramer

    2016-07-21

    Most properties of liquid water are determined by its hydrogen-bond network. Because forming an aqueous interface requires termination of this network, one might expect the molecular level properties of interfacial water to markedly differ from water in bulk. Intriguingly, much prior experimental and theoretical work has found that, from the perspective of their time-averaged structure and picosecond structural dynamics, hydrogen-bonded OH groups at an air/water interface behave the same as hydrogen-bonded OH groups in bulk liquid water. Here we report the first experimental observation of interfacial water's libration (i.e. frustrated rotation) using the laser-based technique vibrational sum frequency spectroscopy. We find this mode has a frequency of 834 cm(-1), ≈165 cm(-1) higher than in bulk liquid water at the same temperature and similar to bulk ice. Because libration frequency is proportional to the stiffness of water's rotational potential, this increase suggests that one effect of terminating bulk water's hydrogen bonding network at the air/water interface is retarding rotation of water around intact hydrogen bonds. Because in bulk liquid water the libration plays a key role in stabilizing reaction intermediates and dissipating excess vibrational energy, we expect the ability to probe this mode in interfacial water to open new perspectives on the kinetics of heterogeneous reactions at aqueous interfaces.

  3. An apparatus to manipulate and identify individual Ba ions from bulk liquid Xe.

    Science.gov (United States)

    Twelker, K; Kravitz, S; Montero Díez, M; Gratta, G; Fairbank, W; Albert, J B; Auty, D J; Barbeau, P S; Beck, D; Benitez-Medina, C; Breidenbach, M; Brunner, T; Cao, G F; Chambers, C; Cleveland, B; Coon, M; Craycraft, A; Daniels, T; Daugherty, S J; Davis, C G; DeVoe, R; Delaquis, S; Didberidze, T; Dilling, J; Dolinski, M J; Dunford, M; Fabris, L; Farine, J; Feldmeier, W; Fierlinger, P; Fudenberg, D; Giroux, G; Gornea, R; Graham, K; Hall, C; Heffner, M; Herrin, S; Hughes, M; Jiang, X S; Johnson, T N; Johnston, S; Karelin, A; Kaufman, L J; Killick, R; Koffas, T; Krücken, R; Kuchenkov, A; Kumar, K S; Leonard, D S; Leonard, F; Licciardi, C; Lin, Y H; MacLellan, R; Marino, M G; Mong, B; Moore, D; Odian, A; Ostrovskiy, I; Ouellet, C; Piepke, A; Pocar, A; Retiere, F; Rowson, P C; Rozo, M P; Schubert, A; Sinclair, D; Smith, E; Stekhanov, V; Tarka, M; Tolba, T; Tosi, D; Vuilleumier, J-L; Walton, J; Walton, T; Weber, M; Wen, L J; Wichoski, U; Yang, L; Yen, Y-R; Zhao, Y B

    2014-09-01

    We describe a system to transport and identify barium ions produced in liquid xenon, as part of R&D towards the second phase of a double beta decay experiment, nEXO. The goal is to identify the Ba ion resulting from an extremely rare nuclear decay of the isotope (136)Xe, hence providing a confirmation of the occurrence of the decay. This is achieved through Resonance Ionization Spectroscopy (RIS). In the test setup described here, Ba ions can be produced in liquid xenon or vacuum and collected on a clean substrate. This substrate is then removed to an analysis chamber under vacuum, where laser-induced thermal desorption and RIS are used with time-of-flight mass spectroscopy for positive identification of the barium decay product.

  4. Bulk and Surface Properties of Liquid Al-Li and Li-Zn Alloys

    Science.gov (United States)

    Trybula, Marcela; Gancarz, Tomasz; Gasior, Wladyslaw; Pasturel, Alain

    2014-11-01

    Physicochemical properties like density, surface tension, and viscosity of liquid binary Al-Li and Li-Zn alloys have been measured using draining crucible method. The experimentally measured surface-tension values have been compared to theoretical results based either on the Butler model or the compound formation model assuming the existence of the most favored A 1 B 2 and A 2 B 3 clusters. Several models for viscosity calculation have been also applied and discussed in confrontation with measured data. Finally, the clustering effects in the liquid Al-Li and Li-Zn alloys have been examined using two microscopic functions, i.e., the concentration fluctuation function in the long-wavelength limit and the Warren-Cowley short-range order parameter.

  5. Playing with ionic liquid mixtures to design engineered CO2 separation membranes.

    Science.gov (United States)

    Tomé, Liliana C; Florindo, Catarina; Freire, Carmen S R; Rebelo, Luís Paulo N; Marrucho, Isabel M

    2014-08-28

    Ionic liquids have been explored as attractive alternative media for CO2 separation not only due to their low volatility but also due to their highly tuneable nature. Aiming at designing highly efficient liquid phases for flue gas separation and natural gas purification, this work focuses on the use of binary ionic liquid mixtures containing sulfate and/or cyano-functionalized anions. Several mixtures were prepared and their gas transport properties through supported ionic liquid membranes (SILMs) were investigated. The thermophysical properties of these mixtures, namely viscosity and density (data presented and discussed in ESI), were also measured so that trends between transport properties and thermophysical properties could be evaluated. The results obtained indicate that depending on the anions mixed, membranes with fine-tuned gas permeabilities, diffusivities and solubilities can be obtained. Additionally, SILMs prepared with these ionic liquid mixtures are on the upper bound of the CO2/N2 separation, or even may surpass it, indicating their potential for separating CO2 in low-pressure post-combustion processes. Overall, the use of ionic liquid mixtures combining the most selective anions with the least viscous anions is a highly promising strategy to design advanced engineered liquid phases for CO2 separation membranes.

  6. Standard Practice for Processing Aerospace Liquid Samples for Particulate Contamination Analysis Using Membrane Filters

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2008-01-01

    1.1 This practice covers the processing of liquids in preparation for particulate contamination analysis using membrane filters and is limited only by the liquid-to-membrane filter compatibility. 1.2 The practice covers the procedure for filtering a measured volume of liquid through a membrane filter. When this practice is used, the particulate matter will be randomly distributed on the filter surface for subsequent contamination analysis methods. 1.3 The practice describes procedures to allow handling particles in the size range between 2 and 1000 μm with minimum losses during handling. 1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

  7. Microporous hollow fibre membrane modules as gas-liquid contactors. Part 1. Physical mass transfer processes : A specific application

    NARCIS (Netherlands)

    Kreulen, H.; Versteeg, G.F.; Swaaij, W.P.M. van

    1993-01-01

    Gas-liquid mass transfer has been studied in a membrane module with non-wetted microporous fibres in the laminar flow regime. This new type of gas/liquid contactor can be operated stabily over a large range of gas and liquid flows because gas and liquid phase do not influence each other directly. Th

  8. Influence of Ionic Liquids on the Selectivity of Ion Exchange-Based Polymer Membrane Sensing Layers.

    Science.gov (United States)

    Mendecki, Lukasz; Callan, Nicole; Ahern, Meghan; Schazmann, Benjamin; Radu, Aleksandar

    2016-07-16

    The applicability of ion exchange membranes is mainly defined by their permselectivity towards specific ions. For instance, the needed selectivity can be sought by modifying some of the components required for the preparation of such membranes. In this study, a new class of materials -trihexyl(tetradecyl)phosphonium based ionic liquids (ILs) were used to modify the properties of ion exchange membranes. We determined selectivity coefficients for iodide as model ion utilizing six phosphonium-based ILs and compared the selectivity with two classical plasticizers. The dielectric properties of membranes plasticized with ionic liquids and their response characteristics towards ten different anions were investigated using potentiometric and impedance measurements. In this large set of data, deviations of obtained selectivity coefficients from the well-established Hofmeister series were observed on many occasions thus indicating a multitude of applications for these ion-exchanging systems.

  9. 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.

  10. Descemet′s membrane detachment managed with perfluro-n-octane liquid

    Directory of Open Access Journals (Sweden)

    M Ashok Kumar

    2012-01-01

    Full Text Available We report the case of a 68-year-old male who developed Descemet′s membrane detachment after temporal clear corneal phacoemulsification which did not settle with air or viscoelastic injection. The Descemet′s membrane was successfully reattached with restoration of 20/50 vision with the help of perfluro-n-octane liquid. To our knowledge, this is the first such case to be reported.

  11. 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

  12. 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...

  13. Indirect evaporative cooler using membrane-contained, liquid desiccant for dehumidification

    Energy Technology Data Exchange (ETDEWEB)

    Kozubal, Eric Joseph

    2016-12-13

    An indirect evaporative cooler for cooling inlet supply air from a first temperature to a second, lower temperature using a stream of liquid coolant and a stream of exhaust or purge air. The cooler includes a first flow channel for inlet supply air and a second flow channel adjacent the first for exhaust air. The first and second flow channels are defined in part by sheets of a membrane permeable to water vapor such that mass is transferred as a vapor through the membrane from the inlet supply air to a contained liquid desiccant for dehumidification and also to the exhaust air as heat is transferred from the inlet supply air to the liquid coolant. A separation wall divides the liquid desiccant and the coolant but allows heat to be transferred from the supply air to the coolant which releases water vapor to the counter or cross flowing exhaust air.

  14. 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

  15. Effect of incongruent crystallization on glass–liquid transition features of a bulk metal glass

    Energy Technology Data Exchange (ETDEWEB)

    Aji, D.P.B.; Johari, G.P., E-mail: joharig@mcmaster.ca

    2015-09-10

    Highlights: • Ce{sub 66}Al{sub 10}Cu{sub 20}Co{sub 4} glass did not crystallize during aging for nine years. • Crystallization's onset temperature was higher for the aged glass. • Incongruent melt embedding the crystals had higher viscosity and T{sub g}. • Increase in crystallization increased the T{sub g} and broadened the T{sub g}-endotherm. - Abstract: It is known that most multi-component glasses cold-crystallize incongruently on heating through the temperature range of their ultraviscous melt. If the incongruent melt's composition changes with time, its viscosity, η, and the glass–liquid transition temperature, T{sub g}, would change. Since the η, relaxation time, and expansion coefficient of a liquid in its partially crystallized mixture cannot be determined, we used scanning calorimetry to study the liquid–glass–liquid transition during thermal cycling of the incongruently crystallizing Ce{sub 66}Al{sub 10}Cu{sub 20}Co{sub 4} glass. Its T{sub g} is 358 K for 20 K/min and 354 K for 10 K/min heating rates, and its ultraviscous melt crystallized incongruently when heated beyond the hysteresis peak of its heat capacity scan. Its sample that had been aged for nine years at ambient conditions had a higher crystallization-onset temperature than an un-aged sample. Delayed enthalpy gain on heating of the aged glass is ∼1/5th of the enthalpy lost on its crystallization. Crystallization of the melt occurred on both the heating and cooling paths of a thermal cycle and T{sub g} of the un-aged glass increased as the volume fraction of the compositionally different glass, f{sub gl}, decreased. The increase was by 8 K after the 24th cycle of 20 K/min, and by 11 K after the 13th cycle of 10 K/min cooling-heating. The highest T{sub g} values reached differed by ∼1 K, which indicates that closely similar T{sub g}s may be reached if the total time period for thermal cycling (at different rates) is kept the same. As f{sub gl} approached its limiting

  16. Liquid Chromatographic Determination of Alogliptin in Bulk and in its Pharmaceutical Preparation

    OpenAIRE

    El-Bagary, Ramzia I.; Elkady, Ehab F.; Ayoub, Bassam M.

    2012-01-01

    In this work, a reversed-phase liquid chromatographic (RP-LC) method has been developed for the determination of alogliptin (ALG) based on isocratic elution using a mobile phase consisting of potassium dihydrogen phosphate buffer pH (4.6)-acetonitrile (20:80, v/v) at a flow rate of 1 mL min−1 with UV detection at 215 nm. Chromatographic separation was achieved on a Symmetry® cyanide column (150 mm × 4.6 mm, 5 μm). Linearity, accuracy and precision were found to be acceptable over the concentr...

  17. 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.

  18. ns or fs pulsed laser ablation of a bulk InSb target in liquids for nanoparticles synthesis.

    Science.gov (United States)

    Semaltianos, N G; Hendry, E; Chang, H; Wears, M L; Monteil, G; Assoul, M; Malkhasyan, V; Blondeau-Patissier, V; Gauthier-Manuel, B; Moutarlier, V

    2016-05-01

    Laser ablation of bulk target materials in liquids has been established as an alternative method for the synthesis of nanoparticles colloidal solutions mainly due to the fact that the synthesized nanoparticles have bare, ligand-free surfaces since no chemical precursors are used for their synthesis. InSb is a narrow band gap semiconductor which has the highest carrier mobility of any known semiconductor and nanoparticles of this material are useful in optoelectronic device fabrication. In this paper a bulk InSb target was ablated in deionized (DI) water or ethanol using a nanosecond (20 ns) or a femtosecond (90 fs) pulsed laser source, for nanoparticles synthesis. In all four cases the largest percentage of the nanoparticles are of InSb in the zincblende crystal structure with fcc lattice. Oxides of either In or Sb are also formed in the nanoparticles ensembles in the case of ns or fs ablation, respectively. Formation of an oxide of either element from the two elements of the binary bulk alloy is explained based on the difference in the ablation mechanism of the material in the case of ns or fs pulsed laser irradiation in which the slow or fast deposition of energy into the material results to mainly melting or vaporization, respectively under the present conditions of ablation, in combination with the lower melting point but higher vaporization enthalpy of In as compared to Sb. InSb in the metastable phase with orthorhombic lattice is also formed in the nanoparticles ensembles in the case of fs ablation in DI water (as well as oxide of InSb) which indicates that the synthesized nanoparticles exhibit polymorphism controlled by the type of the laser source used for their synthesis. The nanoparticles exhibit absorption which is observed to be extended in the infrared region of the spectrum.

  19. A variational approach to the liquid-vapor phase transition for hardcore ions in the bulk and in nanopores

    Science.gov (United States)

    Loubet, Bastien; Manghi, Manoel; Palmeri, John

    2016-07-01

    We employ a field-theoretical variational approach to study the behavior of ionic solutions in the grand canonical ensemble. To describe properly the hardcore interactions between ions, we use a cutoff in Fourier space for the electrostatic contribution of the grand potential and the Carnahan-Starling equation of state with a modified chemical potential for the pressure one. We first calibrate our method by comparing its predictions at room temperature with Monte Carlo results for excess chemical potential and energy. We then validate our approach in the bulk phase by describing the classical "ionic liquid-vapor" phase transition induced by ionic correlations at low temperature, before applying it to electrolytes at room temperature confined to nanopores embedded in a low dielectric medium and coupled to an external reservoir of ions. The ionic concentration in the nanopore is then correctly described from very low bulk concentrations, where dielectric exclusion shifts the transition up to room temperature for sufficiently tight nanopores, to high concentrations where hardcore interactions dominate which, as expected, modify only slightly this ionic "capillary evaporation."

  20. Micellar liquid chromatographic determination of sertaconazole and terconazole in bulk, pharmaceutical dosage forms and spiked human plasma

    Directory of Open Access Journals (Sweden)

    Mohamed Rizk

    2014-06-01

    Full Text Available A micellar liquid chromatographic method was developed for the determination of sertaconazole and terconazole in bulk, dosage forms and human plasma using intersil cyano column and mobile phase consisting of 0.1 M sodium dodecyl sulphate, 20% 1-propanol, and 0.3% triethylamine in 0.02 M ortho-phosphoric acid (pH 4 at 225 nm. Different chromatographic parameters were studied, e.g. types of columns, pH of mobile phase, concentration of sodium dodecyl sulphate, 1-propanol, triethylamine, etc. The method was validated over the concentration ranges 8–40 and 16–80 μg/ml, for sertaconazole and terconazole, respectively. The method was sensitive with limits of detection of 1.24 and 1.67 μg/ml for sertaconazole and terconazole in bulk, respectively. Inter and intra-day results showed % RSD < 0.9% and 1.55% for sertaconazole and terconazole, respectively. The result obtained by the proposed method was compared with that obtained by the reference HPLC technique. Furthermore, the proposed method was successfully applied as a stability-indicating method for the determination of drugs under different stressed conditions. The method showed good selectivity, repeatability, linearity and sensitivity according to the evaluation of the validation parameters.

  1. Rapid estimation of tadalafil by reverse-phase high-performance liquid chromatography method in bulk and tablet formulation

    Directory of Open Access Journals (Sweden)

    P H Sonawane

    2013-01-01

    Full Text Available The simple, selective, precise and accurate reverse-phase high-performance liquid chromatography method was developed and validated for analysis of tadalafil in bulk and tablet dosage form. The column was Inertsil C18 (150×4.6 mm; 5 μm in isocratic mode. The mobile phase used was phosphate buffer (10 mM, pH 3.2 and acetonitrile (50:50% v/v at the flow rate of 1.0 ml/min with ultraviolet detection at 295 nm at ambient temperature. The retention time for tadalafil was found to be 4.01 min. Linearity was observed in the concentration range from 60 to 140 μg/ml for tadalafil with a correlation coefficient of (r2 0.9998. The method was validated according to International Conference on Harmonisation guidelines in terms of linearity, accuracy, precision and specificity. Hence, the proposed method can be utilized for routine quality control of tadalafil in bulk and tablet dosage form.

  2. Rare-gas liquids - Equation of state and reduced-pressure, reduced-bulk-modulus, and reduced-sound-velocity functions

    Science.gov (United States)

    Schlosser, Herbert

    1990-01-01

    This paper is concerned with verification of the applicability of the Vinet et al. (1987) universal equation of state to the liquid phase of the rare-gas elements under pressure. As previously observed in solids and liquids metals, to a good approximation, in the absence of phase transitions, plots of the logarithms of the reduced pressure function, of the reduced sound velocity, and of the reduced bulk modulus, are all linear functions of 1 - X over the entire experimental pressure range. The results obtained on the rare-gas liquids are comparable in accuracy to those obtained in previous work on solids and liquid metals.

  3. Effect of choline carboxylate ionic liquids on biological membranes.

    Science.gov (United States)

    Rengstl, Doris; Kraus, Birgit; Van Vorst, Matthew; Elliott, Gloria D; Kunz, Werner

    2014-11-01

    Choline carboxylates, ChCm, with m=2-10 and choline oleate are known as biocompatible substances, yet their influence on biological membranes is not well-known, and the effect on human skin has not previously been investigated. The short chain choline carboxylates ChCm with m=2, 4, 6 act as hydrotropes, solubilizing hydrophobic compounds in aqueous solution, while the longer chain choline carboxylates ChCm with m=8, 10 and oleate are able to form micelles. In the present study, the cytotoxicity of choline carboxylates was tested using HeLa and SK-MEL-28 cells. The influence of these substances on liposomes prepared from dipalmitoylphosphatidylcholine (DPPC) was also evaluated to provide insights on membrane interactions. It was observed that the choline carboxylates with a chain length of m>8 distinctly influence the bilayer, while the shorter ones had minimal interaction with the liposomes.

  4. A model for a liquid membrane separation stage

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-02-01

    The coupled mixer-settlers having a common settling zone suggested for use to extract fission products from a conversion reactor blanket are analogues of membrane apparatuses and at a first glance in terms of hydrodynamics do not differ from conventional mixer-settlers. However, the common settling zone complicates both the design solutions and their modelling. For example, different emulsion types can result in mixers and it is not known how this fact will affect phenomena such as separation rates, disperse phase entrainment under conditions close to flooding. For initial studies of the feasibility of the process in principle and the primary optimization of the structure of the transfer scheme one needs to have a model and a program to calculate the statics of a multistage membrane facility of this type.

  5. High Performance Liquid Chromatographic Analysis of Almotriptan Malate in Bulk and Tablets

    Directory of Open Access Journals (Sweden)

    Chandra Bala Sekaran

    2013-02-01

    Full Text Available Purpose: A simple RP-HPLC method has been developed and validated for the determination of almotriptan malate (ATM in bulk and tablets. Methods: Chromatographic separation of ATM was achieved by using a Thermo Scientific C18 column. A Mobile phase containing a mixture of methanol, water and acetic acid (4:8:0.1 v/v was pumped at the flow rate of 1 mL/min. Detection was performed at 227 nm. According to ICH guidelines, the method was validated. Results: The calibration curve was linear in the concentration range 5–60 μg/mL for the ATM with regression coefficient 0.9999. The method was precise with RSD <1.2%. Excellent recoveries of 99.60 - 100.80% proved the accuracy of the method. The limits of detection and quantification were found to be 0.025 and 0.075 μg/mL, respectively. Conclusion: The method was successfully applied for the quantification of ATM in tablets with acceptable accuracy and precision.

  6. Assembling Synthesis of ZnSe Orthohexagonal Slices through Emulsion Liquid Membrane System of Gas-liquid Transport

    Institute of Scientific and Technical Information of China (English)

    Lu LIU; Qing Sheng WU; Ya Ping DING; Hua Jie LIU

    2005-01-01

    Orthohexagonal slices assembled by ZnSe quantum dots were synthesized through emulsion liquid membrane system. These orthohexagonal slices were 1.5-3.5 μm in side length and were self-assembled by ZnSe quantum dots of 2-3 nm. It was proposed the surfactant molecules on ZnSe quantum dots played a key role in the self-assembly process.

  7. Ion-selective supported liquid membranes placed under steady-state diffusion control.

    Science.gov (United States)

    Tompa, Károly; Birbaum, Karin; Malon, Adam; Vigassy, Tamás; Bakker, Eric; Pretsch, Ernö

    2005-12-01

    Supported liquid membranes are used here to establish steady-state concentration profiles across ion-selective membranes rapidly and reproducibly. This opens up new avenues in the area of nonequilibrium potentiometry, where reproducible accumulation and depletion processes at ion-selective membranes may be used to gain valuable analytical information about the sample. Until today, drifting signals originating from a slowly developing concentration profile across the ion-selective membrane made such approaches impractical in zero current potentiometry. Here, calcium- and silver-selective membranes were placed between two identical aqueous electrolyte solutions, and the open circuit potential was monitored upon changing the composition of one solution. Steady state was reached in approximately 1 min with 25-microm porous polypropylene membranes filled with bis(2-ethylhexyl) sebacate doped with ionophore and lipophilic ion exchanger. Ion transport across the membrane resulted on the basis of nonsymmetric ion-exchange processes at both membrane sides. The steady-state potential was calculated as the sum of the two membrane phase boundary potentials, and good correspondence to experiment was observed. Concentration polarizations in the contacting aqueous phases were confirmed with stirring experiments. It was found that interferences (barium in the case of calcium electrodes and potassium with silver electrodes) induce a larger potential change than expected with the Nicolsky equation because they influence the level of polarization of the primary ion (calcium or silver) that remains potential determining.

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

    Directory of Open Access Journals (Sweden)

    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.

  9. 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...

  10. Activating photonic crystal membrane nanocavities by infiltrating with liquid crystals or luminescent colloidal nanocrystals

    NARCIS (Netherlands)

    Dündar, M.A.; Christova, C.; Silov, A.Y.; Karouta, F.; Nötzel, R.; Wienk, M.; Salemink, H.; Van der Heijden, R.W.

    2010-01-01

    Liquid crystal (LC, Merk 5 CB) is infiltrated into active, InAs quantum dots embedded, InGaAsP membrane type nanocavities to investigate the possible effect of the LC orientation on active cavity tuning. The tuning is demonstrated thermally and thermo-optically. The thermal tuning showed that the ca

  11. Activating photonic crystal membrane nanocavities by infiltrating with liquid crystals or luminescent colloidal nanocrystals

    NARCIS (Netherlands)

    Dündar, M.A.; Christova, C.; Silov, A.Y.; Karouta, F.; Nötzel, R.; Wienk, M.; Salemink, H.; Van der Heijden, R.

    2010-01-01

    Liquid crystal (LC, Merk 5 CB) is infiltrated into active, InAs quantum dots embedded, InGaAsP membrane type nanocavities to investigate the possible effect of the LC orientation on active cavity tuning. The tuning is demonstrated thermally and thermo-optically. The thermal tuning showed that the c

  12. Electromembrane extraction of peptides - fundamental studies on the supported liquid membrane

    DEFF Research Database (Denmark)

    Seip, Knut Fredrik; Stigsson, Jeanette; Gjelstad, Astrid;

    2011-01-01

    A large screening of different components in the supported liquid membrane (SLM) in electromembrane extraction (EME) was performed to test the extraction efficiency on eight model peptides. Electromembrane extraction from a 500 µL acidified aqueous sample containing the model peptides in the conc...

  13. How do polymerized room-temperature ionic liquid membranes plasticize during high pressure CO2 permeation?

    NARCIS (Netherlands)

    Simons, K.; Nijmeijer, D.C.; Bara, J.B.; Noble, R.D.; Wessling, M.

    2010-01-01

    Room-temperature ionic liquids (RTILs) are a class of organic solvents that have been explored as novel media for CO2 separations. Polymerized RTILs (poly(RTILs)) can be synthesized from RTIL monomers to form dense, solid gas selective membranes. It is of interest to understand the permeation proper

  14. Liquid Membrane Transport Behavior of Functional Substituted Crown Ethers for Amino Acids

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Three functional substituted crown ethers were synthesized as liquid membrane transport carriers for amino acids. The result obtained shows that this kind of ditopic ligands can transport sodium salt of amino acids in good rate value especially the one with two pyridinyl groups as binding site outside the macrocycle.

  15. 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

  16. 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

  17. Selectivity of NF membrane for treatment of liquid waste containing uranium

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-07-01

    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{sub 6} to UO{sub 2} in the cycle of nuclear fuel. This waste contains uranium concentration on average 7.0 mg L{sup -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)

  18. Impact of ionic liquids in aqueous solution on bacterial plasma membranes studied with molecular dynamics simulations.

    Science.gov (United States)

    Lim, Geraldine S; Zidar, Jernej; Cheong, Daniel W; Jaenicke, Stephan; Klähn, Marco

    2014-09-04

    The impact of five different imidazolium-based ionic liquids (ILs) diluted in water on the properties of a bacterial plasma membrane is investigated using molecular dynamics (MD) simulations. Cations considered are 1-octyl-3-methylimidazolium (OMIM), 1-octyloxymethyl-3-methylimidazolium (OXMIM), and 1-tetradecyl-3-methylimidazolium (TDMIM), as well as the anions chloride and lactate. The atomistic model of the membrane bilayer is designed to reproduce the lipid composition of the plasma membrane of Gram-negative Escherichia coli. Spontaneous insertion of cations into the membrane is observed in all ILs. Substantially more insertions of OMIM than of OXMIM occur and the presence of chloride reduces cation insertions compared to lactate. In contrast, anions do not adsorb onto the membrane surface nor diffuse into the bilayer. Once inserted, cations are oriented in parallel to membrane lipids with cation alkyl tails embedded into the hydrophobic membrane core, while the imidazolium-ring remains mostly exposed to the solvent. Such inserted cations are strongly associated with one to two phospholipids in the membrane. The overall order of lipids decreased after OMIM and OXMIM insertions, while on the contrary the order of lipids in the vicinity of TDMIM increased. The short alkyl tails of OMIM and OXMIM generate voids in the bilayer that are filled by curling lipids. This cation induced lipid disorder also reduces the average membrane thickness. This effect is not observed after TDMIM insertions due to the similar length of cation alkyl chain and the fatty acids of the lipids. This lipid-mimicking behavior of inserted TDMIM indicates a high membrane affinity of this cation that could lead to an enhanced accumulation of cations in the membrane over time. Overall, the simulations reveal how cations are inserted into the bacterial membrane and how such insertions change its properties. Moreover, the different roles of cations and anions are highlighted and the fundamental

  19. Lipid Raft-Mediated Membrane Tethering and Delivery of Hydrophobic Cargos from Liquid Crystal-Based Nanocarriers.

    Science.gov (United States)

    Nag, Okhil K; Naciri, Jawad; Oh, Eunkeu; Spillmann, Christopher M; Delehanty, James B

    2016-04-20

    A main goal of bionanotechnology and nanoparticle (NP)-mediated drug delivery (NMDD) continues to be the development of novel biomaterials that can controllably modulate the activity of the NP-associated therapeutic cargo. One of the desired subcellular locations for targeted delivery in NMDD is the plasma membrane. However, the controlled delivery of hydrophobic cargos to the membrane bilayer poses significant challenges including cargo precipitation and lack of specificity. Here, we employ a liquid crystal NP (LCNP)-based delivery system for the controlled partitioning of a model dye cargo from within the NP core into the plasma membrane bilayer. During synthesis of the NPs, the water-insoluble model dye cargo, 3,3'-dioctadecyloxacarbocyanine perchlorate (DiO), was efficiently incorporated into the hydrophobic LCNP core as confirmed by multiple spectroscopic analyses. Conjugation of a PEGylated cholesterol derivative to the NP surface (DiO-LCNP-PEG-Chol) facilitated the localization of the dye-loaded NPs to lipid raft microdomains in the plasma membrane in HEK 293T/17 cell. Analysis of DiO cellular internalization kinetics revealed that when delivered as a LCNP-PEG-Chol NP, the half-life of DiO membrane residence time (30 min) was twice that of free DiO (DiO(free)) (15 min) delivered from bulk solution. Time-resolved laser scanning confocal microscopy was employed to visualize the passive efflux of DiO from the LCNP core and its insertion into the plasma membrane bilayer as confirmed by Förster resonance energy transfer (FRET) imaging. Finally, the delivery of DiO as a LCNP-PEG-Chol complex resulted in the attenuation of its cytotoxicity; the NP form of DiO exhibited ∼30-40% less toxicity compared to DiO(free). Our data demonstrate the utility of the LCNP platform as an efficient vehicle for the combined membrane-targeted delivery and physicochemical modulation of molecular cargos using lipid raft-mediated tethering.

  20. Synthesis of Pyrrolidinium-type Poly(Ionic Liquid) Membranes for Antibacterial Applications.

    Science.gov (United States)

    Qin, Jing; Guo, Jiangna; Xu, Qiming; Zheng, Zhiqiang; Mao, Hailei; Yan, Feng

    2017-03-08

    Pyrrolidinium-type small molecule ionic liquids (ILs), poly(ionic liquid) (PIL) homopolymers, and their corresponding PIL membranes were synthesized and used for antibacterial applications. The influences of substitutions at the N position of pyrrolidinium cation on the antimicrobial activities against both Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) were studied by minimum inhibitory concentration (MIC). The antibacterial efficiency of both the small molecule ILs and PIL homopolymers increased with the increase of the alkyl chain length of substitutions. Furthermore, PIL homopolymers show relatively lower MIC values, indicating better antimicrobial activities than those of corresponding small molecule ILs. However, the antibacterial properties of the PIL membranes are contrary to corresponding ILs and PIL homopolymers, which reducing with the increase of alkyl chain length. Furthermore, the resultant PIL membranes show excellent hemocompatibility and low cytotoxicity towards human cells, demonstrating clinical feasibility in topical applications.

  1. Mechanism of proton transport in ionic-liquid-doped perfluorosulfonic acid membranes.

    Science.gov (United States)

    Kumar, Milan; Venkatnathan, Arun

    2013-11-21

    Ionic-liquid-doped perfluorosulfonic acid membranes (PFSA) are promising electrolytes for intermediate/high-temperature fuel cell applications. In the present study, we examine proton-transport pathways in a triethylammonium-triflate (TEATF) ionic liquid (IL)-doped Nafion membrane using quantum chemistry calculations. The IL-doped membrane matrix contains triflic acid (TFA), triflate anions (TFA(-)), triethylamine (TEA), and triethylammonium cations (TEAH(+)). Results show that proton abstraction from the sulfonic acid end groups in the membrane by TFA(-) facilitates TEAH(+) interaction with the side-chains. In the IL-doped PFSA membrane matrix, proton transfer from TFA to TEA and TFA to TFA(-) occurs. However, proton transfer from a tertiary amine cation (TEAH(+)) to a tertiary amine (TEA) does not occur without an interaction with an anion (TFA(-)). An anion interaction with the amine increases its basicity, and as a consequence, it takes a proton from a cation either instantly (if the cation is freely moving) or with a small activation energy barrier of 2.62 kcal/mol (if the cation is interacting with another anion). The quantum chemistry calculations predict that anions are responsible for proton-exchange between cations and neutral molecules of a tertiary amine. Results from this study can assist the experimental choice of IL to provide enhanced proton conduction in PFSA membrane environments.

  2. Polyelectrolyte microcapsules as ionic liquid reservoirs within ionomer membrane to confer high anhydrous proton conductivity

    Science.gov (United States)

    Zhang, Haoqin; Wu, Wenjia; Li, Yifan; Liu, Yong; Wang, Jingtao; Zhang, Bing; Liu, Jindun

    2015-04-01

    Herein, novel composite membranes are prepared by embedding methacrylic acid polyelectrolyte microcapsules (PMCs) into sulfonated poly(ether ether ketone) (SPEEK) matrix, followed by impregnating imidazole-type ionic liquids (ILs). Within the composite membrane, the lumens of PMCs act as IL reservoirs, which provide large space for IL storage and thus significantly elevate the IL uptake. The IL leaching measurement suggests that the cross-linked shells of PMCs manipulate the IL release, endowing the composite membrane with high IL retention. Moreover, the high IL retention renders the composite membrane more anhydrous hopping sites (e.g., the imidazole groups on IL and the acid-base pairs between imidazole and sulfonic acid groups), imparting a facilitated proton conduction via Grotthuss mechanism. In particular, the composite membrane containing 12% PMCs achieves a high anhydrous proton conductivity of 33.7 mS cm-1 at 150 °C. The same membrane also exhibits a surprising steady-state IL retention of 36.9% after leaching in liquid water.

  3. Bulk meltwater flow and liquid water content of snowpacks mapped using the electrical self-potential (SP) method

    Science.gov (United States)

    Thompson, Sarah S.; Kulessa, Bernd; Essery, Richard L. H.; Lüthi, Martin P.

    2016-02-01

    Our ability to measure, quantify and assimilate hydrological properties and processes of snow in operational models is disproportionally poor compared to the significance of seasonal snowmelt as a global water resource and major risk factor in flood and avalanche forecasting. We show here that strong electrical self-potential fields are generated in melting in situ snowpacks at Rhone Glacier and Jungfraujoch Glacier, Switzerland. In agreement with theory, the diurnal evolution of self-potential magnitudes ( ˜ 60-250 mV) relates to those of bulk meltwater fluxes (0-1.2 × 10-6 m3 s-1) principally through the permeability and the content, electrical conductivity and pH of liquid water. Previous work revealed that when fresh snow melts, ions are eluted in sequence and electrical conductivity, pH and self-potential data change diagnostically. Our snowpacks had experienced earlier stages of melt, and complementary snow pit measurements revealed that electrical conductivity ( ˜ 1-5 × 10-6 S m-1) and pH ( ˜ 6.5-6.7) as well as permeabilities (respectively ˜ 9.7 × 10-5 and ˜ 4.3 × 10-5 m2 at Rhone Glacier and Jungfraujoch Glacier) were invariant. This implies, first, that preferential elution of ions was complete and, second, that our self-potential measurements reflect daily changes in liquid water contents. These were calculated to increase within the pendular regime from ˜ 1 to 5 and ˜ 3 to 5.5 % respectively at Rhone Glacier and Jungfraujoch Glacier, as confirmed by ground truth measurements. We conclude that the electrical self-potential method is a promising snow and firn hydrology sensor owing to its suitability for (1) sensing lateral and vertical liquid water flows directly and minimally invasively, (2) complementing established observational programs through multidimensional spatial mapping of meltwater fluxes or liquid water content and (3) monitoring autonomously at a low cost. Future work should focus on the development of self-potential sensor

  4. 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.

  5. Preparation and Performance of Bipolar Membranes with Liquid Ion-Exchange Medium

    Institute of Scientific and Technical Information of China (English)

    苏静; 余立新; 郝继华

    2003-01-01

    The current density is rather low in solid bipolar membranes, because the water transfer rate is relatively slow across solid bipolar membranes made of solid ion-exchange materials. This paper describes the use of polymer solutions, such as phosphatic poly(vinyl alcohol) solution, poly(acrylic acid) solution and poly(vinyl alcohol) solutions with dispersed cation/anion-exchange resin particles to prepare bipolar membranes. The 0.1 mol/L NaOH and the 0.05 mol/L H2SO4 were used to test the performance of the bipolar membranes. For a fixed liquid layer thickness, both the current density and the selectivity increase with the concentration increase of a polyelectrolyte solution. The maximum current density measured in the experiment was 1497 A/m2 with a selectivity of 96.8%.

  6. Study on transport of Dy(Ⅲ) by dispersion supported liquid membrane

    Institute of Scientific and Technical Information of China (English)

    PEI Liang; YAO Binghua; FU Xinglong

    2009-01-01

    The transport of Dy(Ⅲ) through a dispersion supported liquid membrane (DSLM) consisting of polyvinylidene fluoride mem-brane (PVDF) as the liquid membrane support and dispersion solution including HC1 solution as the stripping solution and 2-ethyl hexyl phosphonic aeid-mono-2-ethyl hexyl ester (PC-88A) dissolved in kerosene as the membrane solution, was studied. The effects of pH value, initial concentration of Dy(Ⅲ) and different ionic strength in the feed phase, volume ratio of membrane solution and stripping solution, con-centration of HC1 solution, concentration of carder, different stripping agents in the dispersion phase on transport of Dy(Ⅲ) were also inves-tigated, respectively. As a result, when the concentration of HCI solution was 4.0 mol/L, concentration of PC-88A was 0.10 mol/L, and vol-ume ratio of membrane solution and stripping solution was 40:20 in the dispersion phase, and pH value was 5.0 in the feed phase, the trans-port effect of Dy(Ⅲ) was the best. Ionic strength had no obvious effect on transport of Dy(Ⅲ). Under the optimum condition studied, when initial concentration of Dy(Ⅲ) was 0.8×10-4 mol/L, the transport rate of Dy(Ⅲ) was up to 96.2% during the transport time of 95 min. The kinetic equation was developed in terms of the law of mass diffusion and the theory of interface chemistry. The diffusion coefficient of Dy(Ⅲ) in the membrane and the thickness of diffusion layer between feed phase and membrane phase were obtained and the values were 1.99×10-7 m2/s and 15.97 μm, respectively. The results were in good agreement with experimental results.

  7. Optimization of Copper Removal from Aqueous Solutions Using Emulsion Liquid Membranes with Benzoylacetone as a Carrier

    Directory of Open Access Journals (Sweden)

    Loreto León

    2017-01-01

    Full Text Available The presence of heavy metals in aqueous solutions above certain limits represents a serious threat to the environment due to their toxicity and non-degradability. Thus, the removal of these metals from contaminated waters has received increasing attention during recent decades. This paper describes the removal of Cu(II from aqueous solutions by emulsion liquid membranes, through a carrier-facilitated counter-transport mechanism, using benzoylacetone as the carrier and HCl as the stripping agent (protons as counter-ions. To optimize the Cu(II removal process, the effect of the following operating parameters on the on the stability of the emulsion liquid membrane and on the Cu(II removal efficiency was studied: feed pH, HCl concentration in the permeate phase, carrier and emulsifier concentration in the membrane phase, feed phase/emulsion phase and permeate phase/membrane phase volume ratios, emulsification time and speed in the primary emulsion preparation and stirring speed in the whole feed phase/emulsion phase system. Typical membrane transport parameters, such as flux and permeability, were also determined. Optimal Cu(II removal conditions were: 5.5 feed pH, 10 kg/m3 benzoylacetone concentration in the membrane phase, 18.250 kg/m3 HCl concentration in the permeate phase, 50 kg/m3 Span 80 concentration in the membrane phase, 200 rpm stirring rate, 5 min emulsification time, 2700 rpm emulsification rate, 2:1 feed:emulsion volume ratio and 1:1 permeate:membrane volume ratio. In these optimal conditions, 80.3% of Cu(II was removed in 15 min with an apparent initial flux and permeability of 0.3384 kg·m−3·min−1 and 0.3208 min−1, respectively.

  8. 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

  9. Lithium-Ion-Conducting Electrolytes: From an Ionic Liquid to the Polymer Membrane

    Science.gov (United States)

    Fernicola, A.; Weise, F. C.; Greenbaum, S. G.; Kagimoto, J.; Scrosati, B.; Soleto, A.

    2009-01-01

    This work concerns the design, the synthesis, and the characterization of the N-butyl-N-ethylpiperidinium N,N-bis(trifluoromethane)sulfonimide (PP24TFSI) ionic liquid (IL). To impart Li-ion transport, a suitable amount of lithium N,N-bis-(trifluoromethane)sulfonimide (LiTFSI) is added to the IL. The Li–IL mixture displays ionic conductivity values on the order of 10−4 S cm−1 and an electrochemical stability window in the range of 1.8–4.5 V vs Li+/Li. The voltammetric analysis demonstrates that the cathodic decomposition gives rise to a passivating layer on the surface of the working electrode, which kinetically extends the stability of the Li/IL interface as confirmed by electrochemical impedance spectroscopy measurements. The LiTFSI–PP24TFSI mixture is incorporated in a poly(vinylidene fluoride-co-hexafluoropropylene) matrix to form various electrolyte membranes with different LiTFSI–PP24TFSI contents. The ionic conductivity of all the membranes resembles that of the LiTFSI–IL mixture, suggesting an ionic transport mechanism similar to that of the liquid component. NMR measurements demonstrate a reduction in the mobility of all ions following the addition of LiTFSI to the PP24TFSI IL and when incorporating the mixture into the membrane. Finally, an unexpected but potentially significant enhancement in Li transference number is observed in passing from the liquid to the membrane electrolyte system. PMID:20354582

  10. Rare earth extraction from wet process phosphoric acid by emulsion liquid membrane

    Institute of Scientific and Technical Information of China (English)

    张利昌; 陈前林; 康超; 马昕; 杨尊良

    2016-01-01

    The recovery of rare earths (RE) during the wet processing of phosphoric acid is very important, the method of emul-sion liquid membrane (ELM) with di(2-ethylhexly) phosphate (D2EHPA) as carrier has the high selectivity while cannot provide a satisfactory extraction rate. Here novel method of emulsion liquid membrane (ELM) using Aniline as carrier to extract RE from the feed solution was proposed. The method could increase the extraction rate of RE in the real sample to 93%. The effects of dif-ferent parameters such as type and concentration of carrier and surfactant, hydrochloric acid concentration, organic to internal phase volume ratio, membrane to external phase volume ratio on extraction of RE3+ were investigated. Quantitative extraction (>93%) of RE3+ was observed with 6 vol.% Aniline and 4 vol.% T154 liquid membrane at external to internal phase volume ratio of 10 for the feed solution. The proposed method of ELM using Aniline as carrier can be expected to provide a practical, efficient, and economical method for extracting RE from phosphate leach solution with high acidity in the industry of wet process phospho-ric acid.

  11. Gas-liquid interfacial plasmas producing reactive species for cell membrane permeabilization

    Science.gov (United States)

    Kaneko, Toshiro; Sasaki, Shota; Takashima, Keisuke; Kanzaki, Makoto

    2017-01-01

    Gas-liquid interfacial atmospheric-pressure plasma jets (GLI-APPJ) are used medically for plasma-induced cell-membrane permeabilization. In an attempt to identify the dominant factors induced by GLI-APPJ responsible for enhancing cell-membrane permeability, the concentration and distribution of plasma-produced reactive species in the gas and liquid phase regions are measured. These reactive species are classified in terms of their life-span: long-lived (e.g., H2O2), short-lived (e.g., O2•−), and extremely-short-lived (e.g., •OH). The concentration of plasma-produced •OHaq in the liquid phase region decreases with an increase in solution thickness (plasma-induced cell-membrane permeabilization is found to decay markedly as the thickness of the solution increases. Furthermore, the horizontally center-localized distribution of •OHaq, resulting from the center-peaked distribution of •OH in the gas phase region, corresponds with the distribution of the permeabilized cells upon APPJ irradiation, whereas the overall plasma-produced oxidizing species such as H2O2aq in solution exhibit a doughnut-shaped horizontal distribution. These results suggest that •OHaq is likely one of the dominant factors responsible for plasma-induced cell-membrane permeabilization. PMID:28163376

  12. Backside calibration potentiometry: ion activity measurements with selective supported liquid membranes by calibrating from the inner side of the membrane.

    Science.gov (United States)

    Malon, Adam; Bakker, Eric; Pretsch, Ernö

    2007-01-15

    In direct potentiometry, the magnitude of the measured potentials is used to determine the composition of the sample. While this places rather formidable demands on the required reproducibility of the associated potential measurements, typically on the order of microvolts, in vitro clinical analyses of blood samples are today successfully performed with direct potentiometry using ion-selective electrodes (ISEs). Unfortunately, most other analytical situations do not permit the sensor to be recalibrated every few minutes, as in environmental monitoring or in vivo measurements, and direct potentiometry is often bound to fail as an accurate method in these circumstances. This paper introduces a novel direction for potentiometric sensing, termed backside calibration potentiometry. Chemical asymmetries across thin supported liquid ISE membranes are assessed by determining the direction of potential drift upon changing the stirring rate on either side of the membrane. Disappearance of this drift indicates the disappearance of concentration gradients across the membrane and is used to determine the sample composition if the solution composition at the backside of the membrane and the interfering ion concentration in the sample are known. For practical determinations, the concentration of either the primary or the interfering ion is varied in the reference solution until the stirring effect disappears. The procedure is demonstrated with a Ca2+-selective membrane using Ba2+ as the dominant interfering ion. Another example includes the determination of Pb2+ in environmental samples where the pH is adjusted to a known level. At pH 4.0, H+ turns out to be the dominant interfering ion. The practical applicability of the method is shown with different environmental water samples, for which the results obtained with the novel method are compared with those obtained by traditional calibration using standard additions. The limitations of the novel method in terms of accuracy and

  13. Constructing Ionic Liquid-Filled Proton Transfer Channels within Nanocomposite Membrane by Using Functionalized Graphene Oxide.

    Science.gov (United States)

    Wu, Wenjia; Li, Yifan; Chen, Pingping; Liu, Jindun; Wang, Jingtao; Zhang, Haoqin

    2016-01-13

    Herein, nanocomposite membranes are fabricated based on functionalized graphene oxides (FGOs) and sulfonated poly(ether ether ketone) (SPEEK), followed by being impregnated with imidazole-type ionic liquid (IL). The functional groups (acidic group or basic group) on FGOs generate strong interfacial interactions with SPEEK chains and then adjust their motion and stacking. As a result, the nanocomposite membranes possess tunable interfacial domains as determined by its free volume characteristic, which provides regulated location for IL storage. The stored ILs act as hopping sites for water-free proton conduction along the FGO-constructed interfacial channels. The microstructure at SPEEK-FGO interface governs the IL uptake and distribution in nanocomposite membrane. Different from GO and vinyl imidazole functionalized GO (VGO), the presence of acidic (-SO3H) groups confers the p-styrenesulfonic acid functionalized GO (SGO) incorporated nanocomposite membrane loose interface and strong electrostatic attraction with imidazole-type IL, imparting an enhanced IL uptake and anhydrous proton conductivity. Nanocomposite membrane containing 7.5% SGO attains the maximum IL uptake of 73.7% and hence the anhydrous conductivity of 21.9 mS cm(-1) at 150 °C, more than 30 times that of SPEEK control membrane (0.69 mS cm(-1)). In addition, SGOs generate electrostatic attractions to the ILs confined within SGO-SPEEK interface, affording the nanocomposite membrane enhanced IL retention ability.

  14. Parallel artificial liquid membrane extraction of acidic drugs from human plasma.

    Science.gov (United States)

    Roldán-Pijuán, Mercedes; Pedersen-Bjergaard, Stig; Gjelstad, Astrid

    2015-04-01

    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 wells in a 96-well donor plate and diluted with HCl to protonate the acidic drugs. The acidic drugs were extracted as protonated species from the individual plasma samples, through corresponding artificial liquid membranes each comprising 2 μL of dihexyl ether, and into corresponding acceptor solutions each comprising 50 μL of 25 mM ammonia solution (pH 10). The liquid membranes and the acceptor solutions were located in a 96-well filter plate, which was sandwiched with the 96-well donor plate during extraction. Parallel extraction of several samples was performed for 15 to 60 min, followed by high-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 extraction was accomplished from plasma. Linearity was obtained for all six drugs in the range 0.025-10 μg/mL, with r (2) values ranging between 0.998 and 1.000. Precision data were in the range 3-22% RSD, and accuracy data were within 72-130% with spiked plasma samples. Based on the current experiences, PALME showed substantial potential for future high-throughput bioanalysis of non-polar acidic drugs.

  15. Preparation and characterization of nonaqueous proton-conducting membranes with protic ionic liquids.

    Science.gov (United States)

    Lu, Fei; Gao, Xinpei; Yan, Xiaojun; Gao, Hejun; Shi, Lijuan; Jia, Han; Zheng, Liqiang

    2013-08-14

    Hybrid Nafion membranes were successfully fabricated by incorporating with protic imidazolium ionic liquids 1-(2-aminoethyl)-3-methylimidazolium chloride ([MimAE]Cl), 1-(2-hydroxylethyl)-3-methylimidazolium chloride ([MimHE]Cl), and 1-carboxylmethyl-3-methylimidazolium chloride ([MimCM]Cl) for high-temperature fuel cells. The composite membranes were characterized by impedance spectroscopy, small-angle X-ray scattering (SAXS), scanning electronic microscopy (SEM), and thermogravimetric analysis (TGA). The incorporated protic ionic liquids enhance the doping of phosphoric acid (PA) and result in a relatively high ionic conductivity. The Nafion/10 wt % [MimAE]Cl/PA composite membrane exhibits an ionic conductivity of 6.0 mS/cm at 130 °C without humidification. [MimAE]Cl can swell the Nafion matrix more homogeneously than [MimHE]Cl or [MimCM]Cl, which results in a better ionic conductivity. It is notable that the composite Nafion/IL/PA membranes have a better thermal stability than the pristine Nafion membranes.

  16. Polymer Electrolyte Fuel Cells Membrane Hydration by Direct Liquid Water Contact

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, M.S.; Zawodzinski, C.; Gottesfeld, S.

    1998-11-01

    An effective means of providing direct liquid hydration of the membrane tends to improve performance particularly of cells with thicker membranes or at elevated temperatures. Supplying the water to the membrane from the anode flow-field through the anode backing via wicks would appear to have advantages over delivering the water through the thickness of the membrane with regards to the uniformity and stability of the supply and the use of off-the-shelf membranes or MEAs. In addition to improving cell performance, an important contribution of direct liquid hydration approaches may be that the overall fuel cell system becomes simpler and more effective. The next steps in the evolution of this approach are a demonstration of the effectiveness of this technique with larger active area cells as well as the implementation of an internal flow-field water reservoir (to eliminate the injection method). Scale-up to larger cell sizes and the use of separate water channels within the anode flow-field is described.

  17. 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.

  18. An Ionic Liquid Bulk-Modified Carbon Paste Electrode and Its Electrocatalytic Activity toward p-Aminophenol

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ya; ZHENG Jian-Bin

    2007-01-01

    An ionic liquid bulk-modified carbon paste electrode (M-CPE) has been fabricated by using 1-heptyl-3-methylimidazolium bromide as a modifier. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used to evaluate the electrocatalytic activity of the proposed electrode by choosing p-aminophenol (p-AP) as a model compound. Both at a bare carbon paste electrode (CPE) and the M-CPE, p-AP yielded a pair of redox peaks was 0.233 V, while at the M-CPE the AEp was decreased to 0.105 V. Furthermore, the current response to p-AP at the M-CPE was 10.2 times of that at the CPE by DPV. The electron transfer rate constant (ks) of p-AP at the M-CPE was 13.3 times of that at the CPE. Under the optimal condition, a linear dependence of the catalytic current versus advantages of simple prapartion, surface renewal, good reproducibility and good stability. It has been used to determine p-AP in simulated wastewater samples.

  19. Development of a validated liquid chromatographic method for determination of related substances of telmisartan in bulk drugs and formulations.

    Science.gov (United States)

    Rao, R Nageswara; Guru Prasad, K; Gangu Naidu, Ch; Maurya, Pawan K

    2011-11-01

    A simple and rapid reversed phase liquid chromatographic method for separation and determination of the related substances of telmisartan (TLM) was developed and validated. The chromatographic separation was achieved on Lichrospher RP-18 column (250 × 4.6 mm, 5 μm), using 20 mM ammonium acetate containing 0.1% (v/v) triethylamine (pH adjusted to 3.0 with trifluoroacetic acid) and acetonitrile as mobile phase at 25°C. The detection was performed at 254 nm. The method was validated and found to be robust, precise, specific and linear between 0.37 and 500 μg/mL. The limits of detection and quantification of telmisartan were 0.11 and 0.37 μg/mL, respectively. The method was successfully applied to quantify related substances and assay of TLM in bulk drugs and commercial tablets. The related substances relate to a novel synthetic route and different from those A-H impurities reported by European Pharmacopeia.

  20. Micellar high performance liquid chromatographic determination of flunixin meglumine in bulk, pharmaceutical dosage forms, bovine liver and kidney

    Directory of Open Access Journals (Sweden)

    Fathalla F. Belal

    2015-03-01

    Full Text Available A simple, sensitive and rapid liquid chromatographic method was developed and validated for the analysis of flunixin meglumine (flunixin-M in bulk, pharmaceutical dosage forms, bovine liver and kidney. Analytical separation was performed in less than 4 min using a C18 column with UV detection at 284 nm. A micellar solution composed of 0.15 M sodium dodecyl sulphate, 8% n-butanol and 0.3% triethylamine in 0.02 M phosphoric acid buffered at pH 7.0 was used as the mobile phase. The method was fully validated in accordance with the International Conference on Harmonization (ICH guidelines. The limit of detection and the limit of quantitation were 0.02 and 0.06 μg mL−1, respectively. The recoveries obtained were in range of 95.58–106.94% for bovine liver and kidney. High extraction efficiency was obtained without matrix interference in the extraction process and in the subsequent chromatographic determination. The method showed good repeatability, linearity and sensitivity according to the evaluation of the validation parameters.

  1. Approximate solution to predict the enhancement factor for the reactive absorption of a gas in a liquid flowing through a microporous membrane hollow fiber

    NARCIS (Netherlands)

    Kumar, P.S.; Hogendoorn, J.A.; Feron, P.H.M.; Versteeg, G.F.

    2003-01-01

    Approximate solutions for the enhancement factor (based on the traditional mass transfer theories) for gas–liquid systems with a liquid bulk have been adapted to situations where a liquid bulk may be absent and a velocity gradient is present in the mass transfer zone. Such a situation is encountered

  2. Study on the oscillating phenomena of electrical potential across a liquid membrane

    Institute of Scientific and Technical Information of China (English)

    Jin Zhang Gao; Hong Xia Dai; Hua Chen; Jie Ren; Wu Yang

    2007-01-01

    The electrical oscillations across a liquid membrane in water/oil/water system was studied with octanol as oil phase by introducing two opposite charged surfactants in oil and aqueous phase, respectively. The sustained and rhythmic oscillation was observed. To a certain extent, the features of the oscillation (e.g. induction time, frequency, life time and orientation of the pulse pikes) strongly depend on the property of surfactant, dissolved in octanol. The mechanism may be explained by the formation and destruction of dual-ion surfactant membrane accompanying with emulsification at the interface and considering the coupling effect of diffusion and associated reaction in the vicinity of the interface.

  3. Treatment of Zn-Containing Acidic Waste Water by Emulsion Liquid Membrane Process

    Institute of Scientific and Technical Information of China (English)

    王士柱; 何培炯; 郝东萍; 朱永贝睿

    2002-01-01

    Zn-containing waste water from a viscose staple fiber plant has been treated using the emulsion liquid membrane (ELM) process since 1995. The flow sheet and operating parameters of the ELM process are introduced. After adjusting the membrane composition, changing the emulsion phase ratio, and adding a scrubbing step, the ELM process operated normally without trouble for emulsion splitting and mass transport throughput. The splitter voltage was decreased to 3.55 kV. The zinc concentration of treated waste water was lowered to less than 10 mgL-1. More than 95% of the zinc was recovered and reused.

  4. Recovery of Copper Ions from Wastewater by Hollow Fiber Supported Emulsion Liquid Membrane

    Institute of Scientific and Technical Information of China (English)

    郑辉东; 陈晶晶; 王碧玉; 赵素英

    2013-01-01

    Recovery of copper ions from wastewater using a hollow fiber supported emulsion liquid membrane (HFSELM) was studied with LIX984N as carrier, kerosene as diluents, and sulfuric acid solution as stripping phase. Effects of compositions of feed and emulsion liquid phase, flow rates on both sides of membrane, and hollow fiber module parameters were investigated. The stability of the emulsion liquid phase without surfactant and the effect of buffer in the feed phase on the extraction rate were also evaluated. It is found that the stability of the emulsion phase without surfactant is poor. Higher flow velocity gives shorter residence time for the emulsion liquid phase on the tube side, reducing the effect of particle coalescence on the separation process. The extraction rate increases with the increase of feed phase pH, carrier concentration, hydrogen ion concentration in the stripping phase, and ef-fective hollow fiber area. The phase ratio in the emulsion liquid phase has a negative effect on extraction rate. The flow rates on both sides have little influence on the extraction performance of the HFSELM, while buffer addition in the feed solution improves the extraction efficiency.

  5. Advanced Supported Liquid Membranes for Carbon Dioxide Control in Cabin Applications

    Science.gov (United States)

    Wickham, David T.; Gleason, Kevin J.; Engel, Jeffrey R.; Chullen, Cinda

    2016-01-01

    The development of new, robust, life support systems is critical to NASA's continued progress in space exploration. One vital function is maintaining the carbon dioxide (CO2) concentration in the cabin at levels that do not impair the health or performance of the crew. The CO2 removal assembly (CDRA) is the current CO2 control technology on-board the International Space Station (ISS). Although the CDRA has met the needs of the ISS to date, the repeated cycling of the molecular sieve sorbent causes it to break down into small particles that clog filters or generate dust in the cabin. This reduces reliability and increases maintenance requirements. Another approach that has potential advantages over the current system is a membrane that separates CO2 from air. In this approach, cabin air contacts one side of the membrane while other side of the membrane is maintained at low pressure to create a driving force for CO2 transport across the membrane. In this application, the primary power requirement is for the pump that creates the low pressure and then pumps the CO2 to the oxygen recovery system. For such a membrane to be practical, it must have high CO2 permeation rate and excellent selectivity for CO2 over air. Unfortunately, conventional gas separation membranes do not have adequate CO2 permeability and selectivity to meet the needs of this application. However, the required performance could be obtained with a supported liquid membrane (SLM), which consists of a microporous material filled with a liquid that selectively reacts with CO2 over air. In a recently completed Phase II SBIR project, Reaction Systems, Inc. fabricated an SLM that is very close to meeting permeability and selectivity objectives for use in the advanced space suit portable life support system. This paper describes work carried out to evaluate its potential for use in spacecraft cabin application.

  6. Membrane-based recovery of glucose from enzymatic hydrolysis of ionic liquid pretreated cellulose.

    Science.gov (United States)

    Abels, Christian; Thimm, Kristof; Wulfhorst, Helene; Spiess, Antje Christine; Wessling, Matthias

    2013-12-01

    In this work, a membrane-based downstream process for the recovery of glucose from cellulose hydrolysis is described and evaluated. The cellulose is pretreated with the ionic liquid 1,3-dimethyl-imidazolium dimethylphosphate to reduce its crystallinity. After enzymatic conversion of cellulose to glucose the hydrolysate is filtered with an ultrafiltration membrane to remove residual particulates and enzymes. Nanofiltration is applied to purify the glucose from molecular intermediates, such as cellobiose originating from the hydrolysis reaction. Finally, the ionic liquid is removed from the hydrolysate via electrodialysis. Technically, these process steps are feasible. An economic analysis of the process reveals that the selling price of glucose from this production process is about 2.75 €/kg which is too high as compared to the current market price.

  7. Study on Extracting Low Concentration Cadmium from Zinc Hydrometallurgy System by Liquid Membrane Crystallizing Technique

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    The extraction of low concentration cadmium from a system containing high concentration zinc was studied and got CdS product directly. A new liquid membrane system taking DIPSA, TIBPS as carriers, (NH4)2S as precipitating agent was reported. Precipitating Cd2+ in the internal aq. phase that is used to treat sulfuric acid leaching solution of zinc oxide in zinc hydrometallurgy has gotten satisfied results of extracting cadmium from high concentration zinc. After one-stage of batch process under the optimum liquid membrane conditions, 98.6% transferring rate and 98.1% extracting rate of cadmium was obtained with only less than 1.0% transferring rate of zinc, and the feed solution can be purified very well.

  8. 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.

  9. Extraction matrine from Radix Sopheorae Tonkinensis by non-supported liquid membrane extraction technology

    Directory of Open Access Journals (Sweden)

    Zhifeng Guo

    2016-09-01

    Full Text Available Non-Supported Liquid Membrane Extraction (NSLME is a new development extraction technology based on Supported Liquid Membrane Extraction (SLME. Sample extraction assembly is composed of three phases: an acceptor phase: phosphate–sodium dihydrogen phosphate buffer solution at the bottom; an organic phase: chloroform applied as the non-supported liquid membrane in the middle layer; and a donor phase: aqueous solution samples containing alkaloids in the upper layer. The whole system is maintained stable by density difference among the three layers that avoided the mutual interferences. The alkaloid in the donor phase can spread to the underlying acidic acceptor phase, where it is able to form water soluble salt in the acid environment, and thus cannot return to the middle organic phase. Therefore, the transmission of alkaloid is a one-way path, and the extraction of alkaloids can be achieved and enriched. In this study, the extraction of alkaloid was carried out by using matrine aqueous solution as the donor phase, and the extraction quantity and efficiency were investigated by GC/MS. This study evaluated the relationship between extracted quantity and extraction time. The effects of extraction temperature, membrane thickness, pH value of acceptor phase on extraction quantity and efficiency were also studied, and the optimal extraction condition was found. The extracted quantity achieved the largest amount at 45 °C when pure phosphoric acid was applied as the acceptor phase; the organic solvent volume was 0.2 mL. The extraction of alkaloid from Radix Sophorae Tonkinensis was performed under the optimized condition. The extraction rate of matrine was up to 54% after a four-hour extraction. A huge advantage of NSLME technology is that the extracted alkaloid enjoyed high purity compared with that extracted by the traditional Liquid–Liquid Extraction (LLE.

  10. Performance evaluation of microbial electrochemical systems operated with Nafion and supported ionic liquid membranes.

    Science.gov (United States)

    Koók, László; Nemestóthy, Nándor; Bakonyi, Péter; Zhen, Guangyin; Kumar, Gopalakrishnan; Lu, Xueqin; Su, Lianghu; Saratale, Ganesh Dattatraya; Kim, Sang-Hyoun; Gubicza, László

    2017-05-01

    In this work, the performance of dual-chamber microbial fuel cells (MFCs) constructed either with commonly used Nafion(®) proton exchange membrane or supported ionic liquid membranes (SILMs) was assessed. The behavior of MFCs was followed and analyzed by taking the polarization curves and besides, their efficiency was characterized by measuring the electricity generation using various substrates such as acetate and glucose. By using the SILMs containing either [C6mim][PF6] or [Bmim][NTf2] ionic liquids, the energy production of these MFCs from glucose was comparable to that obtained with the MFC employing polymeric Nafion(®) and the same substrate. Furthermore, the MFC operated with [Bmim][NTf2]-based SILM demonstrated higher energy yield in case of low acetate loading (80.1 J g(-1) CODin m(-2) h(-1)) than the one with the polymeric Nafion(®) N115 (59 J g(-1) CODin m(-2) h(-1)). Significant difference was observed between the two SILM-MFCs, however, the characteristics of the system was similar based on the cell polarization measurements. The results suggest that membrane-engineering applying ionic liquids can be an interesting subject field for bioelectrochemical system research.

  11. REMOVAL OF COPPER IONS USING ALIQUAT 336/TBP BASED SUPPORTED LIQUID MEMBRANE

    Directory of Open Access Journals (Sweden)

    Baghdad Medjahed

    2014-03-01

    Full Text Available The sorption of copper (II present in an aqueous media using a supported liquid membrane (SLM by chloride tri-N-octylmethylammonium (Aliquat 336 and Tri-n-butylphosphate (TBP from molar ratio 1:1, with polytetrafluoroethylene (PTFE as a membrane support was studied. The effects of various parameters as initial pH, KSCN concentration and ammonium acetate concentration on the extraction yield were carried out. By a calculation program using CHEAQS V. L20.1, the determination of the percentages of the present species before and after extraction were given, in aqueous medium and on the membrane to be able to determine the relation between the nature of the extracted species and the extraction yield. The 23 factorial design achieve the best conditions of recovery procedure. The recovery of copper (II is almost quantitative (94 %, in one step.

  12. Study on a Novel Disphase Supplying Supported Liquid Membrane for Transport Behavior of Divalent Nickel Ions

    Institute of Scientific and Technical Information of China (English)

    裴亮; 王理明; 郭维; 赵楠

    2012-01-01

    A novel d!sphase supplying supported liquid membrane (DSSLM), containing supplying feed phase andsupplying stripping phase tor transport behavior ot NI(Ⅱ), have been studied. The supplying supported feed phase included feed solution and di(2-ethyhexyl) phosphoric acid (HDEHP) as the carrier in kerosene, and supplying stripping phase included HDEHP as the cartier in kerosene and HC1 as the stripping agent. The effects of volume ratio of membrane solution to feed solution (O/F), pH, initial concentration of Ni(Ⅱ) and ionic strength in the feedsolution, volume ratio of membrane solution to stripping solution (O/S), concentration of H2SO4 solution, HDEHP concentration in the supplying stripping phase on transport of Ni(/I), the advantages of DSSLM compared to the traditional supported liquid membrane (SLM), the system stability, the reuse of membrane solution and the reten- tion of membrane phase were studied. Experimental results indicated that the optimum transpgrt of Ni(Ⅱ) was oh-tained when H2SO4 concentration was 2.00 mol'L-', HDEHP concentration was 0.120 mol·L-1, and O/S was 4· 1 in the supplying stripping phase, O/F was 1 : 10 and pH was 5.20 in the supplying feed phase. The ionic strength in supplying feed phase had no obvious effect on transport of Ni(Ⅱ). When initial Ni(Ⅱ) concentration was 2.00x 10-4 mol/L, the transport percentage of Ni(Ⅱ) was up to 93.1% in 250 min. The kinetic equation was deduced in terms of the law of mass diffusion and the interface chemistry.

  13. Mechanical and optical behavior of a tunable liquid lens using a variable cross section membrane: modeling results

    Science.gov (United States)

    Flores-Bustamante, Mario C.; Rosete-Aguilar, Martha; Calixto, Sergio

    2016-03-01

    A lens containing a liquid medium and having at least one elastic membrane as one of its components is known as an elastic membrane lens (EML). The elastic membrane may have a constant or variable thickness. The optical properties of the EML change by modifying the profile of its elastic membrane(s). The EML formed of elastic constant thickness membrane(s) have been studied extensively. However, EML information using elastic membrane of variable thickness is limited. In this work, we present simulation results of the mechanical and optical behavior of two EML with variable thickness membranes (convex-plane membranes). The profile of its surfaces were modified by liquid medium volume increases. The model of the convex-plane membranes, as well as the simulation of its mechanical behavior, were performed using Solidworks® software; and surface's points of the deformed elastic lens were obtained. Experimental stress-strain data, obtained from a silicone rubber simple tensile test, according to ASTM D638 norm, were used in the simulation. Algebraic expressions, (Schwarzschild formula, up to four deformation coefficients, in a cylindrical coordinate system (r, z)), of the meridional profiles of the first and second surfaces of the deformed convex-plane membranes, were obtained using the results from Solidworks® and a program in the software Mathematica®. The optical performance of the EML was obtained by simulation using the software OSLO® and the algebraic expressions obtained in Mathematica®.

  14. Predicting drug penetration across the blood-brain barrier: comparison of micellar liquid chromatography and immobilized artificial membrane liquid chromatography.

    Science.gov (United States)

    De Vrieze, Mike; Lynen, Frédéric; Chen, Kai; Szucs, Roman; Sandra, Pat

    2013-07-01

    Several in vitro methods have been tested for their ability to predict drug penetration across the blood-brain barrier (BBB) into the central nervous system (CNS). In this article, the performance of a variety of micellar liquid chromatographic (MLC) methods and immobilized artificial membrane (IAM) liquid chromatographic approaches were compared for a set of 45 solutes. MLC measurements were performed on a C18 column with sodium dodecyl sulfate (SDS), polyoxyethylene (23) lauryl ether (Brij35), or sodium deoxycholate (SDC) as surfactant in the micellar mobile phase. IAM liquid chromatography measurements were performed with Dulbecco's phosphate-buffered saline (DPBS) and methanol as organic modifier in the mobile phase. The corresponding retention and computed descriptor data for each solute were used for construction of models to predict transport across the blood-brain barrier (log BB). All data were correlated with experimental log BB values and the relative performance of the models was studied. SDS-based models proved most suitable for prediction of log BB values, followed closely by a simplified IAM method, in which it could be observed that extrapolation of retention data to 0% modifier in the mobile phase was unnecessary.

  15. Pervaporation performance of PPO membranes in dehydration of highly hazardous mmh and udmh liquid propellants.

    Science.gov (United States)

    Moulik, Siddhartha; Kumar, K Praveen; Bohra, Subha; Sridhar, Sundergopal

    2015-05-15

    Polyphenylene oxide (PPO) membranes synthesized from 2,6-dimethyl phenol monomer were subjected to pervaporation-based dehydration of the highly hazardous and hypergolic monomethyl hydrazine (MMH) and unsymmetrical dimethyl hydrazine (UDMH) liquid propellants. Membranes were characterized by TGA, DSC and SEM to study the effect of temperature besides morphologies of surface and cross-section of the films, respectively. Molecular dynamics (MD) simulation was used to study the diffusion behavior of solutions within the membrane. CFD method was employed to solve the governing mass transfer equations by considering the flux coupling. The modeling results were highlighted by the experimental data and were in good agreement. High separation factors (35-70) and reasonable water fluxes (0.1-0.2 kg/m(2)h) were observed for separation of the aqueous azeotropes of MMH (35 wt%) and UDMH (20 wt%) and their further enrichment to >90% purity. Effect of feed composition, membrane thickness and permeate pressure on separation performance of PPO membranes were investigated to determine optimum operating conditions.

  16. Global Analysis of the Membrane Subproteome of Pseudomonas aeruginosa using Liquid Chromatography-Tandem Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Blonder, Josip; Goshe, Michael B.; Xiao, Wenzhong; Camp, David G.; Wingerd, Mark A.; Davis, Ronald W.; Smith, Richard D.

    2004-05-30

    Pseudomonas aeruginosa is one of the most significant opportunistic bacterial pathogens in humans causing infections and premature death in patients with cystic fibrosis, AIDS, severe burns, organ transplants or cancer. Liquid chromatography coupled online with tandem mass spectrometry (LC-MS/MS) was used for the large-scale proteomic analysis of the P. aeruginosa membrane subproteome. Concomitantly, an affinity labeling technique, using iodoacetyl-PEO biotin to tag cysteinyl-containing proteins, permitted the enrichment and detection of lower abundance membrane proteins. The application of these approaches resulted in the identification of 786 proteins. A total of 333 proteins (42%) had a minimum of one transmembrane domain (TMD; ranging from 1 to 14) and 195 proteins were classified as hydrophobic based on their positive GRAVY values (ranging from 0.01 to 1.32). Key integral inner and outer membrane proteins involved in adaptation and antibiotic resistance were conclusively identified, including the detection of 53% of all predicted opr-type porins (outer integral membrane proteins) and all the components of the mexA-mexB-oprM transmembrane protein complex. This work represents the most comprehensive qualitative proteomic analysis of the membrane subproteome of P. aeruginosa and for prokaryotes in general to date.

  17. Development of Bitter Taste Sensor Using Ionic-Liquid/Polymer Membranes

    Science.gov (United States)

    Akutagawa, Nobuyuki; Toida, Jinichi; Amano, Yoshihiko; Ikezaki, Hidekazu; Toko, Kiyoshi; Arikawa, Yukihiko

    A taste sensor is composed of several kinds of lipid/polymer membranes as transducers which convert taste information to electric signal. Thus, the role of membranes is very important to detect various taste components. In this paper, we developed novel membranes which specifically respond to quinine that is typical bitter substances. These membranes were composed of hydrophobic ionic liquid such as N, N, N-trimethyl-N-propylammonium bis(trifluoromethansulfonyl)imide, 1-butyl-3-methylimidazolium hexafluorophosphate and 1-butylpyridinium hexafluorophosphate, a plasticizer, 2-nitrophenyl octyl ether and a polymer, polyvinyl chloride. In addition to quinine, they also showed response to both several kinds of alkaloids such as caffeine and strychnine, and non-alkaloid such as phenylthiocarbamide. The order of these responses was equal to that of the tongue glossopharyngeal nerve of flog. Furthermore, there were the other alkaloids which response to these membranes. Especially in these alkaloids, they showed high response to denatonium benzoate and berberin chloride which have a strong bitter taste.

  18. Size Control and Fractionation of Ionic Liquid Filled Polymersomes with Glassy and Rubbery Bilayer Membranes.

    Science.gov (United States)

    So, Soonyong; Lodge, Timothy P

    2016-05-17

    We demonstrate control over the size of ionic liquid (IL) filled polymeric vesicles (polymersomes) by three distinct methods: mechanical extrusion, cosolvent-based processing in an IL, and fractionation of polymersomes in a biphasic system of IL and water. For the representative ionic liquid (1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide ([EMIM][TFSI])), the size and dispersity of polymersomes formed from 1,2-polybutadiene-b-poly(ethylene oxide) (PB-PEO) and polystyrene-b-poly(ethylene oxide) (PS-PEO) diblock copolymers were shown to be sensitive to assembly conditions. During mechanical extrusion through a polycarbonate membrane, the relatively larger polymersomes were broken up and reorganized into vesicles with mean size comparable to the membrane pore (100 nm radius); the distribution width also decreased significantly after only a few passes. Other routes were studied using the solvent-switch or cosolvent (CS) method, whereby the initial content of the cosolvent and the PEO block length of PS-PEO were systemically changed. The nonvolatility of the ionic liquid directly led to the desired concentration of polymersomes in the ionic liquid using a single step, without the dialysis conventionally used in aqueous systems, and the mean vesicle size depended on the amount of cosolvent employed. Finally, selective phase transfer of PS-PEO polymersomes based on size was used to extract larger polymersomes from the IL to the aqueous phase via interfacial tension controlled phase transfer. The interfacial tension between the PS membrane and the aqueous phase was varied with the concentration of sodium chloride (NaCl) in the aqueous phase; then the larger polymersomes were selectively separated to the aqueous phase due to differences in shielding of the hydrophobic core (PS) coverage by the hydrophilic corona brush (PEO). This novel fractionation is a simple separation process without any special apparatus and can help to prepare monodisperse polymersomes

  19. 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.

  20. Partial delignification of wood and membrane preparation using a quaternary ammonium ionic liquid

    Science.gov (United States)

    Miao, Jiaojiao; Yu, Yongqi; Jiang, Zeming; Tang, Lan; Zhang, Liping

    2017-01-01

    This work determined that southern yellow pine wood can almost be completely dissolved in the quaternary ammonium ionic liquid tetrabutylammonium acetate with dimethyl sulfoxide (in a 2:8 mass ratio), after minimal grinding, upon heating at 85 °C for three dissolution/reconstitution cycles, each 1.5 h. Approximately 34.6% of the native lignin and 67.4% of the native carbohydrates present in the original wood can subsequently be extracted, respectively, and were assessed. A gradual decrease in lignin with increased extraction cycles resulted in increased crystallinity index of the cellulose II in the cellulose-rich residue, as confirmed by X-ray diffraction. An increasingly homogeneous macrostructure in the cellulose-rich residue was also evident from scanning electron microscopy images. Membranes cast directly from either wood or cellulose-rich residue solutions in the same tetrabutylammonium acetate/dimethyl sulfoxide system, were prepared using a papermaking-like process. Morphological and mechanical studies indicated that lignin extraction made the membranes more uniform and flexible. Systematic increases in the fibril lengths and orientations of the recovered materials were also found with decreasing lignin contents on the basis of atomic force microscopy analysis. This work demonstrates that relatively efficient partial separation of pine wood and subsequent membrane preparation are possible using a quaternary ammonium ionic liquid. PMID:28266507

  1. 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).

  2. Determination of Dioxins in Blood Using Nano-baskets Doped in Emulsion Liquid Membranes

    Institute of Scientific and Technical Information of China (English)

    MOKHTARI Bahram; POURABDOLLAH Kobra

    2013-01-01

    Extraction of dioxins from blood samples was carried out by inclusion-facilitated emulsion liquid membrane process.The novelty of this work is the application of nano-baskets of calixarene and emulsion liquid membranes in the selective and efficient preconcentration of dioxin.For this aim,four derivatives ofp-tert-calix[4]arene bearing different sulfonamide moieties were synthesized and their inclusion-extraction parameters were optimized including the calixarene's scaffold and concentration(as the carrier/demulsifier),the diluent type in membrane,the phase and the treat ratio,mixing speed,and initial solute concentration.Determinations were followed by a gas chromatograph and the results reveal that under the optimized operating conditions,the preconcentration of dioxins was improved and the method achieved lower limit of detections(LODs).Under optimal conditions,the figures of merits were determined to be LOD 1.0 pg/L,dynamic range 0.6-112.0 pg/L,RSD 5.5%(n=5),and the maximum enrichment factor and recovery were determined to be 3.3 and 99%,respectively.

  3. Selective extraction of triazine herbicides from food samples based on a combination of a liquid membrane and molecularly imprinted polymers.

    Science.gov (United States)

    Mhaka, Byron; Cukrowska, Ewa; Bui, Bernadette Tse Sum; Ramström, Olof; Haupt, Karsten; Tutu, Hlanganani; Chimuka, Luke

    2009-10-02

    A selective extraction technique based on the combination of liquid membrane (microporous membrane liquid-liquid extraction) and molecularly imprinted polymers (MIP) was applied to triazines herbicides in food samples. Simazine, atrazine and propazine were extracted from aqueous food samples through the hydrophobic porous membrane that was impregnated with toluene, which also formed part of the acceptor phase. In the acceptor phase, the compounds were re-extracted onto MIP particles. The extraction technique was optimised for the amount of molecularly imprinted polymers particles in the organic acceptor phase, extraction time, and type of organic acceptor solvent and desorption solvent. An extraction time of 90 min and 50mg of MIP were found to be optimum parameters. Toluene as the acceptor phase was found to give higher triazines binding onto MIP particles compared to hexane and combinations of diethyl ether and hexane. 90% methanol in water was found to be the best desorption solvent compared to acetonitrile, methanol and water. The selectivity of the technique was demonstrated by extracting spiked lettuce and apple extracts where clean chromatograms were obtained compared to liquid membrane extraction alone or to the microporous membrane liquid-liquid extraction - non-imprinted polymer combination. The MIP showed a certain degree of group specificity and the extraction efficiency in lettuce extract was 79% (0.72) for simazine, 98% (1.55) for atrazine and 86% (3.08) for propazine.

  4. Liquid membrane ion-selective electrodes for potentiometric dosage of coper and nickel

    Directory of Open Access Journals (Sweden)

    MARIA PLENICEANY

    2005-02-01

    Full Text Available This paper presents experimental and theoretical data regarding the preparation and characterization of three liquid-membrane electrodes, which have not been mentioned in the specialized literature so far. The active substances, the solutions of which in nitrobenzene formed the membranes on a graphite rod, are simple complex combinations of Cu(II and Ni(II ions with an organic ligand belonging to the Schiff base class: N-[2-thienylmethilidene]-2-aminoethanol (TNAHE. The Cu2+ -selective and Ni2+ -selective electrodes were used to determine the copper and nickel ions in aqueous solutions, both by direct potentiometry and by potentiometric titration with EDTA. They were also used for the determination of Cu2+ and Ni2+ ions in industrial waters by direct potentiometry.

  5. 新型液膜振荡器%New Type of Liquid Membrane Oscillator

    Institute of Scientific and Technical Information of China (English)

    贺占博; 阎喜龙; 聂玉敏; 张凤才

    1999-01-01

    A new type of liquid membrane oscillator in which non-ionic surfactant is the key component was designed in a U type tube and monitored by a pair of Pt electrodes.The fundamental composition is 1.0% emulsifier OP (aq)/n-butanol:nitrobenzene=1∶5(V/V)/0.5mol· dm-3 NaCl(aq).The molecular formula of emulsifier OP is C8H17 ◎O(CH2CH2O)10H.The mechanism and influence factors were studied by replacing component,changing concentration,adding additive,comparison between different experimental apparatus and auxiliary experiment.The oscillatory mechanism is repetitive formation and abrupt destruction of interface membrane of the surfactant,induced by hydrogen bond between n-butanol and emulsifier OP.

  6. Removal of acetic acid from simulated hemicellulosic hydrolysates by emulsion liquid membrane with organophosphorus extractants.

    Science.gov (United States)

    Lee, Sang Cheol

    2015-09-01

    Selective removal of acetic acid from simulated hemicellulosic hydrolysates containing xylose and sulfuric acid was attempted in a batch emulsion liquid membrane (ELM) system with organophosphorus extractants. Various experimental variables were used to develop a more energy-efficient ELM process. Total operation time of an ELM run with a very small quantity of trioctylphosphine oxide as the extractant was reduced to about a third of those required to attain almost the same extraction efficiency as obtained in previous ELM works without any extractant. Under specific conditions, acetic acid was selectively separated with a high degree of extraction and insignificant loss of xylose, and its purity and enrichment ratio in the stripping phase were higher than 92% and 6, respectively. Also, reused organic membrane solutions exhibited the extraction efficiency as high as fresh organic solutions did. These results showed that the current ELM process would be quite practical.

  7. Extraction of Amino-J Acid from Waste-water by Emulsion Liquid Membrane

    Institute of Scientific and Technical Information of China (English)

    潘碌亭

    2006-01-01

    The emulsion liquid membrane technique was used to extract amino-J acid from industrial dye waste-water. The effects of stirring speed, ratio of the emulsion to water (Rew), ratio of the oil to internal phase (Roi) and membrane phase components on the extraction rate were investigated and optimized. The results showed that the extraction rate of amino-J acid approached 97% when the stirring speed was 300 r/min, Rew 1:6, Roi 1:1, trioctylamine (TOA) 3 mL/100 mL kerosene, and methyl-didecyle-alcohol-acrylate (LMA-2) 3 g/100 mL kerosene, respectively. The extraction rate had not changed with the oil phase reused for times.

  8. Absorption of Low Concentration Sulfur Dioxide Using Liquid-containing Microporous Membrane

    Institute of Scientific and Technical Information of China (English)

    薛娟琴; 兰新哲; 孟令嫒; 李伟达

    2007-01-01

    The absorption of low concentration SO2 in flue gas by using the module of liquid-containing microporous membrane which iS made up of hollow fiber and citric acid-sodium citrate buffer solution was investigated.The absorption efficiency of hydrophilic and hydrophobic membranes by using the concept of dynamic contact angle was mainly studied.The infuences on absorption efficiency from absorption time,flowrate of gas phase,SO2 concentration of gas phase,air pressure,citrate concentration,pH value of solution as well as the generation of sulfate radical in absorption solution were examined.The results indicate that the hydrophobic hollow fiber membrane is better than hydrophilic membrane,the absorption efficiency decreases with increasing absorption time,gas phase flowrate,gas phase SO2 concentration and air pressure,the absorption rate and capacity of SO2 can be improved by increasing the citrate concentration,the absorption efficiency can be improved by increasing the pH value of citrate solution,the concentration of SO4z- in absorption solution increases linearly with the absorption time at a rate around 0.192g/(L·h).

  9. Racemic ofloxacin separation by supported-liquid membrane extraction with two organic phases

    Institute of Scientific and Technical Information of China (English)

    唐课文; 周春山; 蒋新宇

    2003-01-01

    Based on chemical thermodynamic theory, racemic ofloxacin is separatedin chiral systems by hollow fiber liquid-supported membrane technology combining with countercurrently fractional extraction. The two chiral solutions containing L-dibenzoyltartaric acid and D-dibenzoylta- rtaric acid in 1-octanol, flow through the lumen side and the shell side of fibers, respectively. The solution which flows through the lumen side of fibers also contains racemic ofloxacin. The wall of hollow fibers is filled with an aqueous of 0.1 mol/L Na2HPO4/H3PO4 buffer solution of pH = 6.86 containing 2 mmol/L of cetyltrimethyl ammonium bromide for 48 h. The fairly polar ofloxacin can cross the membrane back and forth, but dibenzoyltartaric acids cannot cross it. Fractional chiral extraction theory, mass transfer performance of hollow fiber membrane and enantioselectivity are investigated. Mathematical model of R/S = 0.96e0.03NTU for racemic ofloxacin separation by hollow fiber extraction, is established. The optical purity for ofloxacin enantiomers is up to 90% when 11 hollow fiber membrane modules of 22 cm in length in series are used.

  10. Impact of membrane solid-liquid separation on design of biological nutrient removal activated sludge systems.

    Science.gov (United States)

    Ramphao, M; Wentzel, M C; Merritt, R; Ekama, G A; Young, T; Buckley, C A

    2005-03-20

    Installing membranes for solid-liquid separation into biological nutrient removal (BNR) activated sludge (AS) systems makes a profound difference not only in the design of the BNR system itself, but also in the design approach for the whole wastewater treatment plant (WWTP). In multizone BNR systems with membranes in the aerobic reactor and fixed volumes for the anaerobic, anoxic, and aerobic zones (i.e., fixed volume fractions), the mass fractions can be controlled (within a range) with the interreactor recycle ratios. This zone mass fraction flexibility is a significant advantage in membrane BNR systems over conventional BNR systems with SSTs, because it allows for changing of the mass fractions to optimize biological N and P removal in conformity with influent wastewater characteristics and the effluent N and P concentrations required. For PWWF/ADWF ratios in the upper range (f(q) approximately 2.0), aerobic mass fractions in the lower range (f(maer) secondary settling tanks is not as large (40% to 60%), the cost of the membranes can be offset against sludge thickening and stabilization costs. Moving from a flow-unbalanced raw wastewater system to a flow-balanced (f(q) = 1), low (usually settled) wastewater strength system can double the ADWF capacity of the biological reactor, but the design approach of the WWTP changes from extended aeration to include primary sludge stabilization. The cost of primary sludge treatment then has to be paid from the savings from the increased WWTP capacity.

  11. Parallel artificial liquid membrane extraction as an efficient tool for removal of phospholipids from human plasma

    DEFF Research Database (Denmark)

    Ask, Kristine Skoglund; Bardakci, Turgay; Parmer, Marthe Petrine

    2016-01-01

    Generic Parallel Artificial Liquid Membrane Extraction (PALME) methods for non-polar basic and non-polar acidic drugs from human plasma were investigated with respect to phospholipid removal. In both cases, extractions in 96-well format were performed from plasma (125μL), through 4μL organic solv...... matrix effects were investigated with fluoxetine, fluvoxamine, and quetiapine as model analytes. No signs of matrix effects were observed. Finally, PALME was evaluated for the aforementioned drug substances, and data were in accordance with European Medicines Agency (EMA) guidelines....

  12. Note: Buoyant-force assisted liquid membrane electrochemical etching for nano-tip preparation

    Science.gov (United States)

    Zeng, Yongbin; Wang, Yufeng; Wu, Xiujuan; Xu, Kun; Qu, Ningsong

    2014-12-01

    A liquid membrane electrochemical etching process for preparing nano-tips is proposed by the introduction of buoyant force to the lower tip, in which the lower portion of the anodic wire is immersed into a floating layer. A mathematical model of this method is derived. Both calculation and experimental results demonstrate that the introduction of buoyant force can significantly decrease the tip radius. The lubricating oil and deionized water floating layers were tested for the processing of nano-tips. Further, high-aspect-ratio nano-electrodes were prepared by applying a relative vertical movement to the anodic wire.

  13. 离子液体支撑液膜的研究及应用进展%Progress of supported liquid membrane with ionic liquids

    Institute of Scientific and Technical Information of China (English)

    沈江南; 阮慧敏; 吴东柱; 章杰

    2009-01-01

    回顾了目前为止离子液体支撑液膜的制备方法,离子液体结构,支撑膜结构对离子液体支撑液膜稳定性的影响因素,介绍了其在有机物分离,气体分离、分离反应耦合方面的应用.由于传统的单元操作很难满足污染和对过程集成的要求,对离子液体支撑液膜在未来实现清洁生产的发展方向进行了展望.%Supercritical fluids,room temperature ionic liquids,CO_2 expanded liquids and water,as well as their mixtures are currently regarded as green solvents.As substitution for volatile organic solvent,ionic liquids can be applied in separation process,chemical reaction,electrochemistry,and so on.This review summarizes the recent progress in preparation method of supported liquid membrane with ionic liquids,and the effect of the structure of ionic liquids and support membrane on the stability of the supported liquid with ionic liquids.In addition,their application in organic/organic separation,gas separation,and coupling separation with reaction are also reviewed.The supported liquid membrane with ionic liquids will be one of the ways for clean production.

  14. Effect of Ammonium- and Phosphonium-Based Ionic Liquids on the Separation of Lactic Acid by Supported Ionic Liquid Membranes (SILMs).

    Science.gov (United States)

    Matsumoto, Michiaki; Panigrahi, Abhishek; Murakami, Yuuki; Kondo, Kazuo

    2011-05-13

    Biodegradable polymers have attracted much attention from an environmental point of view. Optically pure lactic acid that can be prepared by fermentation is one of the important raw materials for biodegradable polymer. The separation and purification of lactic acid from the fermentation broth are the major portions of the production costs. We proposed the application of supported ionic liquid membranes to recovering lactic acid. In this paper, the effect of ionic liquids, such as Aliquat 336, CYPHOS IL-101, CYPHOS IL-102, CYPHOS IL-104, CYPHOS IL-109 and CYPHOS IL-111 on the lactic acid permeation have been studied. Aliquat 336, CYPHOS IL-101 and CYPHOS IL-102 were found to be the best membrane solvents as far as membrane stability and permeation of lactic acid are concerned. CYPHOS IL-109 and CYPHOS IL-111 were found to be unsuitable, as they leak out from the pores of the supported liquid membrane (SLM), thereby allowing free transport of lactic acid as well as hydrochloric acid. CYPHOS IL-102 was found to be the most adequate (Permeation rate = 60.41%) among these ionic liquids as far as the separation of lactic acid is concerned. The permeation mechanisms, by which ionic liquid-water complexes act as the carrier of lactate and hydrochloric acid, were proposed. The experimental permeation results have been obtained as opposed to the expected values from the solution-diffusion mechanism.

  15. Effect of Ammonium- and Phosphonium-Based Ionic Liquids on the Separation of Lactic Acid by Supported Ionic Liquid Membranes (SILMs

    Directory of Open Access Journals (Sweden)

    Kazuo Kondo

    2011-05-01

    Full Text Available Biodegradable polymers have attracted much attention from an environmental point of view. Optically pure lactic acid that can be prepared by fermentation is one of the important raw materials for biodegradable polymer. The separation and purification of lactic acid from the fermentation broth are the major portions of the production costs. We proposed the application of supported ionic liquid membranes to recovering lactic acid. In this paper, the effect of ionic liquids, such as Aliquat 336, CYPHOS IL-101, CYPHOS IL-102, CYPHOS IL-104, CYPHOS IL-109 and CYPHOS IL-111 on the lactic acid permeation have been studied. Aliquat 336, CYPHOS IL-101 and CYPHOS IL-102 were found to be the best membrane solvents as far as membrane stability and permeation of lactic acid are concerned. CYPHOS IL-109 and CYPHOS IL-111 were found to be unsuitable, as they leak out from the pores of the supported liquid membrane (SLM, thereby allowing free transport of lactic acid as well as hydrochloric acid. CYPHOS IL-102 was found to be the most adequate (Permeation rate = 60.41% among these ionic liquids as far as the separation of lactic acid is concerned. The permeation mechanisms, by which ionic liquid-water complexes act as the carrier of lactate and hydrochloric acid, were proposed. The experimental permeation results have been obtained as opposed to the expected values from the solution-diffusion mechanism.

  16. Towards stabilization of supported liquid membranes: preparation and characterization of polysulfone support and sulfonated poly (ether ether ketone) coated composite hollow fiber membranes

    NARCIS (Netherlands)

    He, T.

    2008-01-01

    A supported liquid membrane (SLM) contains organic solvent and organic extractant as one organic phase, and a porous support structure. It has been widely investigated for separation and purification of various chemical compounds. SLM has high permeability and selectivity, being regarded as one of t

  17. Evaluation of coupled transport across a liquid membrane as an analytical preconcentration technique.

    Science.gov (United States)

    Cox, J A; Bhatnagar, A; Francis, R W

    1986-09-01

    When two aqueous solutions are separated by a liquid membrane that contains a complexing agent which is a conjugate base of a weak acid, a metal ion can be transported from the solution of the higher pH against its concentration gradient into the more acidic solution. With Cu(II) as the analyte and a liquid membrane consisting of a mixture of oximes dissolved in kerosene, enrichment factors for a prescribed dialysis time in a simple experimental apparatus were nearly independent of Cu(II) concentration over the range 10(-4)-10(-7)M. With 0.1M hydrochloric acid as the receiver, the enrichment factor was independent of ionic strength and of sample pH in the range 4-9. The effect of sample pH on the interference of Fe(III) was examined. With a pH-2.5 formate buffer, the enrichment factor for Cu(II) decreased as the Fe(III) concentration increased, but in a pH-9.3 ammonium buffer, 0.14 mM Fe(III) did not interfere with the transport of Cu(II) from a 16muM copper sample.

  18. A micro-immuno supported liquid membrane assay (mu-ISLMA).

    Science.gov (United States)

    Tudorache, Madalina; Emnéus, Jenny

    2006-02-15

    A chemiluminescent (CL) based micro-immuno supported liquid membrane assay (mu-ISLMA) has been developed that enables clean up, enrichment and detection of simazine in a single miniaturised cartridge system. The mu-ISLM cartridge contains a supported liquid membrane (SLM) sandwiched between a donor and an acceptor plate (channel volumes 1.65 microL), the latter being covered by a thin layer of gold on to which anti-simazine antibodies were covalently immobilised via a self assembled monolayer (SAM) of either dithiobis(11-aminoundecane, hydrochloride) (DTAU) or beta-mercaptoethylamine (beta-MEA). The mu-ISLMA based on DTAU was characterised by both a high apparent extraction efficiency (E(app) = 136%) and high apparent enrichment factor (E(e)(app) = 544), which resulted in a very high sensitivity for simazine (LOD = 0.1 ng L(-1)). The paper discusses the influence of the different SAMs and three different anti-simazine-antibody preparations (polyclonal, affinity purified polyclonal and monoclonal) on the extraction parameters and assay sensitivity. The influence of the sample matrix (e.g. mineral water, orange juice and milk) on the simazine mu-ISLMA was also investigated.

  19. Extraction of Co(II) from aqueous solution using emulsion liquid membrane.

    Science.gov (United States)

    Gasser, M S; El-Hefny, N E; Daoud, J A

    2008-03-01

    The extraction equilibrium of Co(II) from thiocyanate medium by CYANEX 923 (mixture of straight chain alkylated phosphine oxides) in cyclohexane was studied. The stoichiometry of the extraction reaction was postulated based on slope analysis method and the extraction constant Kex was calculated. The stripping percentage of Co(II) with sulphuric acid from the loaded CYANEX 923 was found to increase with the increase in acid concentration. The extraction of Co(II) from aqueous thiocyanate medium into emulsion liquid membrane using CYANEX 923 extractant was also studied. The influence of different parameters such as stirring speed, surfactant concentration, pH of the extractant phase, carrier concentration, internal phase stripping acid concentration, initial Co(II) concentration as well as temperature on the emulsion stability were investigated. The applicability of the emulsion liquid membrane (ELM) process using CYANEX 923 as extractant and SPAN 80 as surfactant for the removal and the concentration of Co(II) from thiocyanate solution was investigated. The results show that it is possible to recover 95% of cobalt in the inner phase after 10 min of contacting time with a concentration factor of 5.

  20. Study on Membrane Microstructures and Characteristics of Infrared Spectra and Nitrogen Release of Solid-Liquid Reaction Coated Urea

    Institute of Scientific and Technical Information of China (English)

    MAO Xiao-yun; FENG Xin; WANG De-han; SUN Ke-jun; LIAO Zong-wen

    2004-01-01

    The membrane microstructures and the mechanism of two coated ureas formed through solidliquid reaction were observed by scanning electron microscope and infrared spectra, the relation of the structural characteristics with the nitrogen release feature was also discussed by combining with nitrogen dissolution in water. The results showed that the membranes were made of solid particles tightly connected to each other and were piled up layer by layer through liquid glue. Porosity and aperture of membrane were determined by compactness of piled layers and the particles in a single layer and also related to the characteristics of coating materials. Research of the infrared spectra of membrane, made of a solid powder and a liquid glue, proved that O-H on the solid surface was bonded with the double bond of the liquid glue, thus forming membrane and keeping it stable. It was found that the two coated ureas showed obvious differences in nitrogen releasing due to their membrane structures, the porosity and aperture of membrane were the critical factors for nitrogen releasing.

  1. Effect of storage duration on the rheological properties of goose liquid egg products and eggshell membranes.

    Science.gov (United States)

    Kumbar, V; Nedomova, S; Trnka, J; Buchar, J; Pytel, R

    2016-07-01

    In practice, goose eggs are increasingly used and, therefore, the rheological properties have to be known for processing. The eggs of geese (Landes Goose, Anser anser f. domestica) were stored for one, 2, 3, 4, 6, and 8 wk at a constant temperature 4°C. First of all, the egg quality parameters were described in terms of egg weight, egg weight loss, egg shape index, yolk height, albumen height, yolk index, albumen index, and Haugh units. In the next step the rheological behavior of liquid egg products (egg yolk, albumen, and whole liquid egg) was studied using a concentric cylinder viscometer. Flow curves of all liquid egg products exhibited non-Newtonian shear thinning behavior. This behavior can be described using the Herschel-Bulkley model and for technical application using the Ostwald-de Waele model. The effect of the storage duration on the rheological behavior is different for the different liquid egg products. With the exception of very low shear rates, the viscosity of the egg yolk as well as of the whole liquid egg decreases with storage time. At lower shear rates there is a tendency toward increased albumen viscosity with storage duration. The storage duration also affects the mechanical properties of the eggshell membrane. This effect has been evaluated in terms of the ultimate tensile strength, fracture strain, and fracture toughness. All these parameters increased with the loading rate, but decreased during the egg storage. These mechanical phenomena should be respected, namely in the design of the egg model for the numerical simulation of the egg behavior under different kinds of the mechanical loading.

  2. High catalytic efficiency of palladium nanoparticles immobilized in a polymer membrane containing poly(ionic liquid) in Suzuki–Miyaura cross-coupling reaction

    OpenAIRE

    Gu, Yingying; Favier, Isabelle; Pradel, Christian; Gin, Douglas L.; Lahitte, Jean-Francois; Noble, Richard D.; Gómez, Montserrat; Remigy, Jean-Christophe

    2015-01-01

    International audience; The elaboration of a polymeric catalytic membrane containing palladium nanoparticles is presented. The membrane was prepared using a photo-grafting process with imidazolium-based ionic liquid monomers as modifying agent and microPES® as support membrane. Ionic liquid serves as a stabilizer and immobilizer for the catalytic species, i.e. palladium nanoparticles. The Suzuki–Miyaura cross-coupling reaction was carried out on the catalytic membrane in flow-through configur...

  3. High flux, positively charged loose nanofiltration membrane by blending with poly (ionic liquid) brushes grafted silica spheres.

    Science.gov (United States)

    Yu, Liang; Zhang, Yatao; Wang, Yuanming; Zhang, Haoqin; Liu, Jindun

    2015-04-28

    Silica spheres modified by poly (ionic liquid) brushes, a novel positively charged nanomaterial is prepared by atom transfer radical polymerization (ATRP). A high flux positively charged loose nanofiltration membrane is fabricated via "blending-phase inversion" method. The morphology structures, hydrophilicity, thermal and mechanical properties, permeation performance of these membranes are investigated in detail. The results reveal that the hybrid membranes have enhanced surface hydrophilicity, water permeability, thermal stability, and mechanical properties. Characterization of membrane separation properties shows that the hybrid membranes possess higher salt permeability and relatively higher rejection for reactive dyes, which may open opportunities for the recycling of reactive dyes wastewater. Moreover, such hybrid membranes have an outstanding operational stability and salts concentration showed little effect on the separation properties.

  4. Role of LiBF4 in Ionic Liquid Membranes for Facilitated CO2 Transport.

    Science.gov (United States)

    Choi, Yeji; Hong, Gil Hwan; Kang, Sang Wook

    2016-03-01

    The ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate (BMIM BF4)/LiBF4 electrolyte was prepared for highly selective facilitated CO2 transport membranes. When LiBF4 was incorporated into BMIM BF4, synergy effects by free Li+ ion and imidazolium cations is expected to enhance the separation performance for CO2/N2 and CO2/CH4. The free state of BF4- ions in BMIM BF4/LiBF4 solutions was investigated by FT-Raman spectroscopy. For the coordination of LiBF4 with BMIMBF4, thermal gravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS) was utilized. Electrolyte membranes consisting of BMIM BF4 and LiBF4 showed selectivities of 8.40 and 8.25 for CO2/N2 and CO2/CH4, respectively. Neat BMIM BF4 membrane showed selectivities of 5.0 and 4.8, respectively. Enhanced separation performance was attributed to increased free Li+ and abundant free imidazolium cations.

  5. Metal-organic framework supported ionic liquid membranes for CO2 capture: anion effects.

    Science.gov (United States)

    Gupta, Krishna M; Chen, Yifei; Hu, Zhongqiao; Jiang, Jianwen

    2012-04-28

    IRMOF-1 supported ionic liquid (IL) membranes are investigated for CO(2) capture by atomistic simulation. The ILs consist of identical cation 1-n-butyl-3-methylimidazolium [BMIM](+), but four different anions, namely hexafluorophosphate [PF(6)](-), tetrafluoroborate [BF(4)](-), bis(trifluoromethylsulfonyl)imide [Tf(2)N](-), and thiocyanate [SCN](-). As compared with the cation, the anion has a stronger interaction with IRMOF-1 and a more ordered structure in IRMOF-1. The small anions [PF(6)](-), [BF(4)](-), and [SCN](-) prefer to locate near to the metal-cluster, particularly the quasi-spherical [PF(6)](-) and [BF(4)](-). In contrast, the bulky and chain-like [BMIM](+) and [Tf(2)N](-) reside near the phenyl ring. Among the four anions, [Tf(2)N](-) has the weakest interaction with IRMOF-1 and thus the strongest interaction with [BMIM](+). With increasing the weight ratio of IL to IRMOF-1 (W(IL/IRMOF-1)), the selectivity of CO(2)/N(2) at infinite dilution is enhanced. At a given W(IL/IRMOF-1), the selectivity increases as [Tf(2)N](-) membrane with W(IL/IRMOF-1) = 1, [SCN](-) is identified to be the most favorable site for CO(2) adsorption. [BMIM][SCN]/IRMOF-1 outperforms polymer membranes and polymer-supported ILs in CO(2) permeability, and its performance surpasses Robeson's upper bound. This simulation study reveals that the anion has strong effects on the microscopic properties of ILs and suggests that MOF-supported ILs are potentially intriguing for CO(2) capture.

  6. Preparation of 6-APA by Enzymatic Bioconversion in an Emulsion Liquid Membrane Reactor

    Institute of Scientific and Technical Information of China (English)

    陆强; 胡鸣; 熊丹柳; 邓修

    2001-01-01

    Production of 6-aminopenicillanic acid (6-APA) by hydrolysis using penicillin acylase (PA) was studied as a model of an enzymatic emulsion liquid membrane (ELM) process. The loss of PA activity was examined for various membrane compositions (organic solvent, surfactant, carrier). The effects of some experimental variables on the stability of emulsion were investigated. It was found that the choice of organic solvent greatly affected tilestability of the emulsion. Increasing the concentration of the carrier in the membrane phase increases the transfer rate of substrate and products but also has a destabilizing effect on the emulsion. The recovery of 6-APA obtained by a di-carrier system (N263-N1923) was much higher than those when either of the di-carriers was used separately.The whole process was controlled both by the enzymatic reaction rate and by the transfer rate of the substrate and the products, however, the ratio of them could be changed by varying the composition of the system. For an optimum condition, it was obtained that the recovery ratio of 6-APA was over 80% and the conversion of benzyl penicillin (PG) was up to 90% in the external phase after 30 minutes. Meanwhile, the breakage percentage of the emulsion was less than 2%.

  7. Morphology, Modulus, and Ionic Conductivity of a Triblock Terpolymer/Ionic Liquid Electrolyte Membrane

    Science.gov (United States)

    McIntosh, Lucas D.; Lodge, Timothy P.

    2013-03-01

    A key challenge in designing solid polymer electrolytes is increasing bulk mechanical properties such as stiffness, without sacrificing ionic conductivity. Previous work has focused on diblock copolymers, where one block is a stiff, glassy insulator and the other is a flexible ion conductor. Disadvantages of these systems include difficulty in achieving network morphologies, which minimize dead-ends for ion transport, and the necessity to operate below both the Tg of the glassy block and the order-disorder temperature. We have investigated the triblock terpolymer poly[isoprene-b-(styrene-co-norbornenylethyl styrene)-b-ethylene oxide] because it self-assembles into a triply-continuous network structure. SAXS and TEM revealed the bulk morphology of INSO to be disordered but strongly correlated after solvent casting from dichloromethane. This apparent disordered network structure was retained after chemical crosslinking and addition of the ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide. Impedance spectroscopy confirmed the expected conductivity for ions confined to continuous PEO channels. The mechanical response before and after crosslinking showed an increase in the material modulus.

  8. Liquid alkali metals - Equation of state and reduced-pressure, bulk-modulus, sound-velocity, and specific-heat functions

    Science.gov (United States)

    Schlosser, Herbert; Ferrante, John

    1989-01-01

    The previous work of Schlosser and Ferrante (1988) on universality in solids is extended to the study of liquid metals. As in the case of solids, to a good approximation, in the absence of phase transitions, plots of the logarithm of the reduced-pressure function H, of the reduced-isothermal-bulk-modulus function b, and of the reduced-sound-velocity function v are all linear in 1-X. Finally, it is demonstrated that ln(Cp/C/v) is also linear in 1-X, where X = (V/V/0/)exp 1/3), and V(0) is the volume at zero pressure.

  9. Liquid water transport characteristics of porous diffusion media in polymer electrolyte membrane fuel cells: A review

    Science.gov (United States)

    Liu, Xunliang; Peng, Fangyuan; Lou, Guofeng; Wen, Zhi

    2015-12-01

    Fundamental understanding of liquid water transport in gas diffusion media (GDM) is important to improve the material and structure design of polymer electrolyte membrane (PEM) fuel cells. Continuum methods of two-phase flow modeling facilitate to give more details of relevant information. The proper empirical correlations of liquid water transport properties, such as capillary characteristics, water relative permeability and effective contact angle, are crucial to two phase flow modeling and cell performance prediction. In this work, researches on these properties in the last decade are reviewed. Various efforts have been devoted to determine the water transport properties for GDMs. However, most of the experimental studies are ex-situ measurements. In-situ measurements for GDMs and extending techniques available to study the catalyst layer and the microporous layer will be further challenges. Using the Leverett-Udell correlation is not recommended for quantitative modeling. The reliable Leverett-type correlation for GDMs, with the inclusion of the cosine of effective contact angle, is desirable but hard to be established for modeling two-phase flow in GDMs. A comprehensive data set of liquid water transport properties is needed for various GDM materials under different PEM fuel cell operating conditions.

  10. High flux, positively charged loose nanofiltration membrane by blending with poly (ionic liquid) brushes grafted silica spheres

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Liang [School of Chemical Engineering and Energy, Zhengzhou University, Zhengzhou 450001 (China); Zhang, Yatao, E-mail: zhangyatao@zzu.edu.cn [School of Chemical Engineering and Energy, Zhengzhou University, Zhengzhou 450001 (China); UNESCO Center for Membrane Science and Technology, School of Chemical Engineering, University of New South Wales, Sydney, NSW 2052 (Australia); Wang, Yuanming; Zhang, Haoqin [School of Chemical Engineering and Energy, Zhengzhou University, Zhengzhou 450001 (China); Liu, Jindun, E-mail: liujindun@zzu.edu.cn [School of Chemical Engineering and Energy, Zhengzhou University, Zhengzhou 450001 (China)

    2015-04-28

    Highlights: • SiO{sub 2} spheres were modified by poly (ionic liquid) brushes via RATRP. • Positively charged NF membranes were fabricated by incorporation of SiO{sub 2}-PIL. • The membranes exhibited higher rejection for dyes and superior penetration for salts. - Abstract: Silica spheres modified by poly (ionic liquid) brushes, a novel positively charged nanomaterial is prepared by atom transfer radical polymerization (ATRP). A high flux positively charged loose nanofiltration membrane is fabricated via “blending-phase inversion” method. The morphology structures, hydrophilicity, thermal and mechanical properties, permeation performance of these membranes are investigated in detail. The results reveal that the hybrid membranes have enhanced surface hydrophilicity, water permeability, thermal stability, and mechanical properties. Characterization of membrane separation properties shows that the hybrid membranes possess higher salt permeability and relatively higher rejection for reactive dyes, which may open opportunities for the recycling of reactive dyes wastewater. Moreover, such hybrid membranes have an outstanding operational stability and salts concentration showed little effect on the separation properties.

  11. A comparison of BNR activated sludge systems with membrane and settling tank solid-liquid separation.

    Science.gov (United States)

    Ramphao, M C; Wentzel, M C; Ekama, G A; Alexander, W V

    2006-01-01

    Installing membranes for solid-liquid separation into biological nutrient removal (BNR) activated sludge (AS) systems makes a profound difference not only to the design of the membrane bio-reactor (MBR) BNR system itself, but also to the design approach for the whole wastewater treatment plant (WWTP). In multi-zone BNR systems with membranes in the aerobic reactor and fixed volumes for the anaerobic, anoxic and aerobic zones (i.e. fixed volume fractions), the mass fractions can be controlled (within a range) with the inter-reactor recycle ratios. This zone mass fraction flexibility is a significant advantage of MBR BNR systems over BNR systems with secondary settling tanks (SSTs), because it allows changing the mass fractions to optimise biological N and P removal in conformity with influent wastewater characteristics and the effluent N and P concentrations required. For PWWF/ADWF ratios (fq) in the upper range (fq approximately 2.0), aerobic mass fractions in the lower range (f(maer) settling and long sludge age). However, the volume reduction compared with equivalent BNR systems with SSTs will not be large (40-60%), but the cost of the membranes can be offset against sludge thickening and stabilisation costs. Moving from a flow unbalanced raw wastewater system to a flow balanced (fq = 1) low (usually settled) wastewater strength system can double the ADWF capacity of the biological reactor, but the design approach of the WWTP changes away from extended aeration to include primary sludge stabilisation. The cost of primary sludge treatment then has to be offset against the savings of the increased WWTP capacity.

  12. Supported liquid membrane-liquid chromatography-mass spectrometry analysis of cyanobacterial toxins in fresh water systems

    Science.gov (United States)

    Mbukwa, Elbert A.; Msagati, Titus A. M.; Mamba, Bhekie B.

    Harmful algal blooms (HABs) are increasingly becoming of great concern to water resources worldwide due to indiscriminate waste disposal habits resulting in water pollution and eutrophication. When cyanobacterial cells lyse (burst) they release toxins called microcystins (MCs) that are well known for their hepatotoxicity (causing liver damage) and have been found in eutrophic lakes, rivers, wastewater ponds and other water reservoirs. Prolonged exposure to low concentrated MCs are equally of health importance as they are known to be bioaccumulative and even at such low concentration do exhibit toxic effects to aquatic animals, wildlife and human liver cells. The application of common treatment processes for drinking water sourced from HABs infested reservoirs have the potential to cause algal cell lyses releasing low to higher amounts of MCs in finished water. Trace microcystins in water/tissue can be analyzed and quantified using Liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS) following solid-phase extraction (SPE) sample clean-up procedures. However, extracting MCs from algal samples which are rich in chlorophyll pigments and other organic matrices the SPE method suffers a number of drawbacks, including cartridge clogging, long procedural steps and use of larger volumes of extraction solvents. We applied a supported liquid membrane (SLM) based technique as an alternative sample clean-up method for LC-ESI-MS analysis of MCs from both water and algal cells. Four (4) MC variants (MC-RR, -YR, -LR and -WR) from lyophilized cells of Microcystis aeruginosa and water collected from a wastewater pond were identified) and quantified using LC-ESI-MS following a SLM extraction and liquid partitioning step, however, MC-WR was not detected from water extracts. Within 45 min of SLM extraction all studied MCs were extracted and pre-concentrated in approximately 15 μL of an acceptor phase at an optimal pH 2.02 of the donor phase (sample). The highest

  13. Numerical simulation of three-dimensional gas/liquid two-phase flow in a proton exchange membrane fuel cell

    Institute of Scientific and Technical Information of China (English)

    ZHUGE Weilin; ZHANG Yangjun; MING Pingwen; LAO Xingsheng; CHEN Xiao

    2007-01-01

    Investigation into the formation and transport of liquid water in proton exchange membrane fuel cells (PEMFCs) is the key to fuel cell water management.A threedimensional gas/liquid two-phase flow and heat transfer model is developed based on the multiphase mixture theory.The reactant gas flow,diffusion,and chemical reaction as well as the liquid water transport and phase change process are modeled.Numerical simulations on liquid water distribution and its effects on the performance of a PEMFC are conducted.Results show that liquid water distributes mostly in the cathode,and predicted cell performance decreases quickly at high current density due to the obstruction of liquid water to oxygen diffusion.The simulation results agree well with experimental data.

  14. A coupled melt-freeze temperature index approach in a one-layer model to predict bulk volumetric liquid water content dynamics in snow

    Science.gov (United States)

    Avanzi, Francesco; Yamaguchi, Satoru; Hirashima, Hiroyuki; De Michele, Carlo

    2016-04-01

    Liquid water in snow rules runoff dynamics and wet snow avalanches release. Moreover, it affects snow viscosity and snow albedo. As a result, measuring and modeling liquid water dynamics in snow have important implications for many scientific applications. However, measurements are usually challenging, while modeling is difficult due to an overlap of mechanical, thermal and hydraulic processes. Here, we evaluate the use of a simple one-layer one-dimensional model to predict hourly time-series of bulk volumetric liquid water content in seasonal snow. The model considers both a simple temperature-index approach (melt only) and a coupled melt-freeze temperature-index approach that is able to reconstruct melt-freeze dynamics. Performance of this approach is evaluated at three sites in Japan. These sites (Nagaoka, Shinjo and Sapporo) present multi-year time-series of snow and meteorological data, vertical profiles of snow physical properties and snow melt lysimeters data. These data-sets are an interesting opportunity to test this application in different climatic conditions, as sites span a wide latitudinal range and are subjected to different snow conditions during the season. When melt-freeze dynamics are included in the model, results show that median absolute differences between observations and predictions of bulk volumetric liquid water content are consistently lower than 1 vol%. Moreover, the model is able to predict an observed dry condition of the snowpack in 80% of observed cases at a non-calibration site, where parameters from calibration sites are transferred. Overall, the analysis show that a coupled melt-freeze temperature-index approach may be a valid solution to predict average wetness conditions of a snow cover at local scale.

  15. Biomimetic Synthesis of CdSe Quantum Dots through Emulsion Liquid Membrane System of Gas-Liquid Transport

    Institute of Scientific and Technical Information of China (English)

    LIU,LU(刘璐); WU,Qing-Sheng,(吴庆生); DING,Ya-Ping(丁亚平); LIU,Hua-Jie(柳华杰); ZHANG,Bao-Quan(张保权)

    2004-01-01

    The cadmium selenide quantum dots (QD) have been synthesized by template-control in an emulsion liquid membrane system.The system consisted of kerosene as solvent,L152 (dialkylene succinimide) as surfactant,N7301 (trialiphatic amine,R3N,R=Cs-C10) as carrier,0.1 mol/L CdC12 solution as internal-aqueous phase and H2Se gas as external phase.Additive organic template agent in internal-aqueous phase was necessary to form CdSe QD.The influence of the nature of template and its concentration on sizes of the formed CdSe QD has also been studied.Transmission electron microscopy showed that the sizes of the products could be controlled down to 3-4nm.X-ray diffraction analysis revealed that the crystals had cubic structure.The formation process and the optical properties of CdSe QD have also been presented.

  16. 离子液体支撑液膜应用研究进展%Application research progress of ionic liquid supported liquid membrane

    Institute of Scientific and Technical Information of China (English)

    王文治; 杨慧琳; 王瑞康; 刘冉; 许永权; 张娟; 赵地顺

    2016-01-01

    离子液体作为一种新型绿色介质,受到研究学者的广泛关注。离子液体具有不易燃、无味、无污染、无蒸汽压、可循环使用等独特性质,被广泛应用于化学化工过程中。离子液体用于膜分离技术具有不易挥发、稳定性好的特点,近来对离子液体在支撑液膜方面的研究备受关注,离子液体支撑液膜在污染性气体的吸收分离方面具有高选择性、高渗透性等优势,在有机物的分离方面具有分离效果明显、耐用性强等优势,在化学反应方面具有催化效率高、可循环使用等优势,本文介绍了离子液体支撑液膜的常用制备方法和膜基材料的选择,探讨了离子液体支撑液膜的稳定性和分离选择性的影响因素,对离子液体支撑液膜在气体分离、有机物的分离、化学反应等方面的应用研究进行了综述。%Ionic liquid, as a new kind of green solvents, have received extensive attention of researchers.Ionic liquid is widely used in chemical process because the unique features,such as nonflammable,tasteless,no pollution,no detectable vapor pressure and recyclable.Ionic liquids used in membrane separation technology have the characteristics of less volatile,immiscibility with contact phase,good stability,etc.Recently much attention has been paid to the study of ionic liquids in the supported liquid membrane,ionic liquid supported liquid membrane has the advantages of high selectivity,and high permeability in the absorption and separation of gas,has the advantages of the separation effect is obvious,strong durability in the separation of organic matter,has the advantages of high catalytic efficiency, recycled in a chemical reaction.This review provides the preparation of ionic liquid supported liquid membrane and the selection of membrane-based material.The factors affecting the stability and separation selectivity of the ionic liquid supported liquid membrane was discussed

  17. Hypothesis: could the signalling function of membrane microdomains involve a localized transition of lipids from liquid to solid state?

    Directory of Open Access Journals (Sweden)

    Joly Etienne

    2004-01-01

    Full Text Available Abstract Background Over the past decade, it has become apparent that specialised membrane microdomains, commonly called rafts, where lipids like sphingolipids and cholesterol are arranged compactly in a liquid ordered phase are involved in cell signalling. Hypothesis The core of the hypothesis presented here is that resting cells may actively maintain their plasma membrane in liquid phase, corresponding to a metastable thermodynamic state. Following a physiological stimulus such as ligands binding to their membrane receptors, the tendency of membrane components to undergo a localised transition towards a gel state would increase, resulting in initial minute solid structures. These few membrane components having undergone a liquid to solid state transition, would then act as seeds for the specific recruitment of additional membrane components whose properties are compatible with the crystalline growth of these initial docks. Cells could therefore be using the propensity of lipids to assemble selectively to generate stable platforms of particular cellular components either for intra-cellular transport or for signal transduction. Testing the hypothesis could presumably be done via biophysical approaches such as EPR spin labelling, X-ray diffraction or FRET coupled to direct microscopic observation of cells to which very localized stimuli would be delivered. Implications Such a model of selective growth of membrane docks would provide an explanation for the existence of different types of microdomains, and for the fact that, depending on the state of the cells and on the procedures used to isolate them, membrane microdomains can vary greatly in their properties and composition. Ultimately, a thorough understanding of how and why lipid domains are assembled in biological membranes will be essential for many aspects of cell biology and medicine.

  18. Improvements in the processing of large grain, bulk Y-Ba-Cu-O superconductors via the use of additional liquid phase

    Science.gov (United States)

    Congreve, Jasmin V. J.; Shi, Yunhua; Dennis, Anthony R.; Durrell, John H.; Cardwell, David A.

    2017-01-01

    A major limitation to the widespread application of Y-Ba-Cu-O (YBCO) bulk superconductors is the relative complexity and low yield of the top seeded melt growth (TSMG) process, by which these materials are commonly fabricated. It has been demonstrated in previous work on the recycling of samples in which the primary growth had failed, that the provision of an additional liquid-rich phase to replenish liquid lost during the failed growth process leads to the reliable growth of relatively high quality recycled samples. In this paper we describe the adaptation of the liquid phase enrichment technique to the primary TSMG fabrication process. We further describe the observed differences between the microstructure and superconducting properties of samples grown with additional liquid-rich phase and control samples grown using a conventional TSMG process. We observe that the introduction of the additional liquid-rich phase leads to the formation of a higher concentration of Y species at the growth front, which leads, in turn, to a more uniform composition at the growth front. Importantly, the increased uniformity at the growth front leads directly to an increased homogeneity in the distribution of the Y-211 inclusions in the superconducting Y-123 phase matrix and to a more uniform Y-123 phase itself. Overall, the provision of an additional liquid-rich phase improves significantly both the reliability of grain growth through the sample thickness and the magnitude and homogeneity of the superconducting properties of these samples compared to those fabricated by a conventional TSMG process.

  19. Development and Validation of a RP-Ultra performance liquid chromatographic Method for Quantification of Topotecan Hydrochloride in Bulk and Injection Dosage Form.

    Science.gov (United States)

    Saini, P K; Jain, C L; Singh, R M; Mathur, S C; Singh, G N

    2010-07-01

    A simple, very fast, precise and accurate reverse phase ultra performance liquid chromatographic method was developed for the determination and validation of topotecan hydrochloride in bulk and injection dosage form. A Waters BEH C18, 50×2.1 mm, 1.7 μm particle size column in gradient mode was used with mobile phase comprising of 0.1% v/v orthophosphoric acid in water and acetonitrile. The analytical column was thermostated at 50° and flow rate was set at 0.4 ml per min, with photo diode array detection at 260 nm. The retention time of topotecan was found 1.38 min. The method was validated in terms of linearity, accuracy, precision and specificity. The calibration curve was found linear between 20 to 60 μg/ml. The limit of detection and limit of quantification were found 0.2353 and 0.7131 μg/ml, respectively. Percentage recoveries were obtained in the range of 98.91% and 99.17%. The proposed method is precise, accurate, selective and reproducible. The ultra performance liquid chromatographic assay procedure, which proved superior because of its greater sensitivity and relatively shorter (4 min) run time, should be an important tool for speedy future analysis of topotecan hydrochloride in bulk and its injection dosage form.

  20. Continuous Hydrolysis and Liquid–Liquid Phase Separation of an Active Pharmaceutical Ingredient Intermediate Using a Miniscale Hydrophobic Membrane Separator

    DEFF Research Database (Denmark)

    Cervera Padrell, Albert Emili; Morthensen, Sofie Thage; Lewandowski, Daniel Jacob

    2012-01-01

    Continuous hydrolysis of an active pharmaceutical ingredient intermediate, and subsequent liquid–liquid (L-L) separation of the resulting organic and aqueous phases, have been achieved using a simple PTFE tube reactor connected to a miniscale hydrophobic membrane separator. An alkoxide product...... a PTFE membrane with 28 cm2 of active area. A less challenging separation of water and toluene was achieved at total flow rates as high as 80 mL/min, with potential to achieve even higher flow rates. The operability and flexibility of the membrane separator and a plate coalescer were compared...

  1. Comparison between experiment and theory in the temperature variation of film tension above the bulk isotropic transition in free-standing liquid-crystal films.

    Science.gov (United States)

    Veum, M; Duelge, L; Droske, J; Nguyen, H T; Huang, C C; Mirantsev, L V

    2009-09-01

    Using differential scanning calorimetry, the transition enthalpies and temperatures for the bulk smectic-isotropic phase transition have been measured for a series of liquid-crystal compounds. For five compounds, those values were used as parameters in a microscopic mean-field model to predict the temperature dependence of the difference in free-energy density between a sample of material in a free-standing smectic film and that in the bulk. The model predicts a weak temperature dependence below the bulk clearing point and a pronounced monotonic increase with temperature above the transition temperature. The compounds used in this study were chosen specifically because they were also the subject of a previous independent experimental study [M. Veum, Phys. Rev. E 74, 011703 (2006)] that demonstrated a sudden monotonic increase in the free-standing film tension with temperature, which is qualitatively consistent with the predictions of the above-mentioned mean-field model. This study presents a direct and quantitative comparison between the predictions of the mean-field model and the results from previous tension experiments.

  2. Hollow fiber liquid-supported membrane technology for enantioseparation of racemic salbutamol by combinatorial chiral selectors

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Enantioseparation of salbutamol solute was carried out in liquid-supported membrane by using a polyvinylidene fluoride hollow-fiber module. The enantioselective transport of solute was facilitated by combinatorial chiral selectors, which were dissolved in toluene organic solvent. The effects of molar concentration ratios of salbutamol to combinatorial chiral selectors, and the pH value of buffer solution on enantioseparation were investigated. The results show that when the molar concentration ratio is 2: 1:1, the maximum separation factor and enantiomer excess are 1.49 and 19.74%, respectively, and the R-enantiomer flux is more than S-enantiomer; the pH value of buffer solution influences the performances of enantioseparartion obviously, and the appropriate range of pH value is7.0-7.2.

  3. Ionic liquid-based membranes as electrolytes for advanced lithium polymer batteries.

    Science.gov (United States)

    Navarra, M A; Manzi, J; Lombardo, L; Panero, S; Scrosati, Bruno

    2011-01-17

    Gel-type polymer electrolytes are formed by immobilizing a solution of lithium N,N-bis(trifluoromethanesulfonyl)imide (LiTFSI) in N-n-butyl-N-ethylpyrrolidinium N,N-bis(trifluoromethanesulfonyl)imide (Py₂₄TFSI) ionic liquid (IL) with added mixtures of organic solvents, such as ethylene, propylene and dimethyl carbonates (EC, PC, and DMC, respectively), into a poly(vinylidenefluoride-co-hexafluoropropylene) (PVdF-HFP) matrix, and their properties investigated. The addition of the organic solvent mixtures results in an improvement of the ionic conductivity and in the stabilization of the interface with the lithium electrode. Conductivity values in the range of 10⁻³-10⁻²  S cm⁻¹ are obtained in a wide temperature range. These unique properties allow the effective use of these membranes as electrolytes for the development of advanced polymer batteries based on a lithium metal anode and an olivine-type lithium iron phosphate cathode.

  4. Threshold for spontaneous oscillation in a three-phase liquid membrane system involving nonionic surfactant.

    Science.gov (United States)

    Nanzai, Ben; Funazaki, Tomohisa; Igawa, Manabu

    2010-09-16

    This study of self-oscillation was conducted using a new three-phase liquid membrane system of ethanol aqueous solution, benzyl alcohol solution with nonionic surfactant, and pure water. Relations of the initial ethanol concentration to the oscillation amplitude and frequency, and to the induction period before oscillations were investigated. The oscillation amplitude is independent of the initial ethanol concentration, but the frequency and the induction period are related to it. The oscillation frequency increased concomitantly with the increased ethanol initial concentration, but the induction period before the electrical oscillations decreased with increasing concentration. To estimate the influence of ethanol diffusion on the electrical oscillations, the ethanol concentration in each phase was measured using separate experiments after different durations of oscillation. The diffusion coefficient was calculated using Fick's second law. Results show successful estimation of the threshold for oscillations. The threshold is defined in terms of the ethanol concentration at the interface between the benzyl alcohol phase and the pure water phase.

  5. Effects of phosphonium-based ionic liquids on phospholipid membranes studied by small-angle X-ray scattering.

    Science.gov (United States)

    Kontro, Inkeri; Svedström, Kirsi; Duša, Filip; Ahvenainen, Patrik; Ruokonen, Suvi-Katriina; Witos, Joanna; Wiedmer, Susanne K

    2016-12-01

    The effects of ionic liquids on model phospholipid membranes were studied by small-angle X-ray scattering, dynamic light scattering (DLS) and zeta potential measurements. Multilamellar 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine liposomes and large unilamellar vesicles composed of l-α-phosphatidylcholine (eggPC) and l-α-phosphatidylglycerol (eggPG) (80:20mol%) or eggPC, eggPG, and cholesterol (60:20:20mol%) were used as biomimicking membrane models. The effects of the phosphonium-based ionic liquids: tributylmethylphosphonium acetate, trioctylmethylphosphonium acetate, tributyl(tetradecyl)-phosphonium acetate, and tributyl(tetradecyl)-phosphonium chloride, were compared to those of 1-ethyl-3-methyl-imidazolium acetate. With multilamellar vesicles, the ionic liquids that did not disrupt liposomes decreased the lamellar spacing as a function of concentration. The magnitude of the effect depended on concentration for all studied ionic liquids. Using large unilamellar vesicles, first a slight decrease in the vesicle size, then aggregation of vesicles was observed by DLS for increasing ionic liquid concentrations. At concentrations just below those that caused aggregation of liposomes, large unilamellar vesicles were coated by ionic liquid cations, evidenced by a change in their zeta potential. The ability of phosphonium-based ionic liquids to affect liposomes is related to the length of the hydrocarbon chains in the cation. Generally, the ability of ionic liquids to disrupt liposomes goes hand in hand with inducing disorder in the phospholipid membrane. However, trioctylmethylphosphonium acetate selectively extracted and induced a well-ordered lamellar structure in phospholipids from disrupted cholesterol-containing large unilamellar vesicles. This kind of effect was not seen with any other combination of ionic liquids and liposomes.

  6. Drag Coefficient of a Liquid Domain in a Fluid Membrane Surrounded by Confined Three-Dimensional Fluids

    Science.gov (United States)

    Fujitani, Youhei

    2013-08-01

    It is thought that, in a biomembrane, some minor lipid constituents are concentrated in a domain called the lipid raft. Some raftlike domains in a lipid-bilayer membrane can be regarded as two-dimensional droplets. The membrane viscosities inside and outside the domain are generally different. The present author previously studied the drag coefficient of a circular liquid domain in a flat fluid membrane surrounded by three-dimensional fluids, which occupy the semi-infinite spaces on both sides of the membrane. Here we generalize this problem by assuming that the surrounding fluids are confined by container walls parallel to the membrane. Errors in the present author's previous studies are also corrected in this paper.

  7. Integration of Nine Steps into One Membrane Reactor To Produce Synthesis Gases for Ammonia and Liquid Fuel.

    Science.gov (United States)

    Li, Wenping; Zhu, Xuefeng; Chen, Shuguang; Yang, Weishen

    2016-07-18

    The synthesis of ammonia and liquid fuel are two important chemical processes in which most of the energy is consumed in the production of H2 /N2 and H2 /CO synthesis gases from natural gas (methane). Here, we report a membrane reactor with a mixed ionic-electronic conducting membrane, in which the nine steps for the production of the two types of synthesis gases are shortened to one step by using water, air, and methane as feeds. In the membrane reactor, there is no direct CO2 emission and no CO or H2 S present in the ammonia synthesis gas. The energy consumption for the production of the two synthesis gases can be reduced by 63 % by using this membrane reactor. This promising membrane reactor process has been successfully demonstrated by experiment.

  8. Separation of carbon dioxide from nitrogen or methane by supported ionic liquid membranes (SILMs): influence of the cation charge of the ionic liquid.

    Science.gov (United States)

    Hojniak, Sandra D; Khan, Asim Laeeq; Hollóczki, Oldamur; Kirchner, Barbara; Vankelecom, Ivo F J; Dehaen, Wim; Binnemans, Koen

    2013-12-05

    Supported ionic liquid membranes (SILMs) are promising tools for the separation of carbon dioxide from other gases. In this paper, new imidazolium, pyrrolidinium, piperidinium, and morpholinium ionic liquids with a triethylene glycol side chain and tosylate anions, as well as their symmetrical dicationic analogues, have been synthesized and incorporated into SILMs. The selectivities for CO2/N2 and CO2/CH4 separations have been measured. The selectivities exhibited by the dicationic ionic liquids are up to two times higher than the values of the corresponding monocationic ionic liquids. Quantum chemical calculations have been used to investigate the difference in the interaction of carbon dioxide with monocationic and dicationic ionic liquids. The reason for the increased gas separation selectivity of the dicationic ionic liquids is two-fold: (1) a decrease in permeance of nitrogen and methane through the ionic liquid layer, presumably due to their less favorable interactions with the gases, while the permeance of carbon dioxide is reduced much less; (2) an increase in the number of interaction sites for the interactions with the quadrupolar carbon dioxide molecules in the dicationic ionic liquids, compared to the monocationic analogues.

  9. Membraner

    DEFF Research Database (Denmark)

    Bach, Finn

    2009-01-01

    Notatet giver en kort introduktion til den statiske virkemåde af membraner og membrankonstruktioner......Notatet giver en kort introduktion til den statiske virkemåde af membraner og membrankonstruktioner...

  10. Effects of ionic liquids on membrane fusion and lipid aggregation of egg-PC liposomes.

    Science.gov (United States)

    Galletti, Paola; Malferrari, Danilo; Samorì, Chiara; Sartor, Giorgio; Tagliavini, Emilio

    2015-01-01

    In this study we have explored the effects of different groups of ionic liquids (ILs) on membrane fusion. The ILs used contain different head groups: N-methylimidazolium, 3-methylpyridinium and N-methylpyrrolidinium; short alkyl or ether functionalized side chains (with one or two ethoxy functionalities), paired with chloride anion. These ILs have been compared with 1-dodecyl-3-methylimidazolium bromide as example of a highly lipophilic IL. The effect of ILs on membrane fusion was investigated through pyrene steady state fluorescence probing, using the IE factor and excimer/monomer ratio (IE/IM) as parameters. The ratio between the vibronic bands of pyrene (I1/I3 ratio) has been used to monitor the effect of ILs on the aggregation properties of egg-PC liposomes. The effect of different ILs' families was evident; the pyridinium ILs induced a greater extent of fusion than pyrrolidinium and imidazolium ILs having the same side chain. Marginal effect could be attributed to different anions. ILs with short alkyl chains were usually more effective than ether functionalized ones. The aggregation behaviors of ILs having dioxygenated chains have been measured in buffer solution.

  11. Highly Sulfonated Diamine Synthesized Polyimides and Protic Ionic Liquid Composite Membranes Improve PEM Conductivity

    Directory of Open Access Journals (Sweden)

    Bor-Kuan Chen

    2015-06-01

    Full Text Available A novel sulfonated diamine was synthesized from 1,4-bis(4-aminophenoxy benzene [pBAB]. Sulfonated polyimides (SPIs were synthesized from sulfonated pBAB, 1,4-bis(4-aminophenoxy-2-sulfonic acid benzenesulfonic acid [pBABTS], various diamines and aromatic dianhydrides. Composite proton exchange membranes (PEMs made of novel SPIs and a protic ionic liquid (PIL 1-vinyl-3-H-imidazolium trifluoromethanesulfonate [VIm][OTf] showed substantially increased conductivity. We prepared an SPI/PIL composite PEM using pBABTS, 4,4′-(9-fluorenylidene dianiline (9FDA as diamine, 3,3′,4,4′-diphenylsulfone tetracarboxylic dianhydride (DSDA as dianhydride and 40 wt % [VIm][OTf] with a high conductivity of 16 mS/cm at 120 °C and anhydrous condition. pBABTS offered better conductivity, since the chemical structure had more sulfonated groups that provide increased conductivity. The new composite membrane could be a promising anhydrous or low-humidity PEM for intermediate or high-temperature fuel cells.

  12. A New Emulsion Liquid Membrane Based on a Palm Oil for the Extraction of Heavy Metals

    Directory of Open Access Journals (Sweden)

    Sanna Björkegren

    2015-04-01

    Full Text Available The extraction efficiency of hexavalent chromium, Cr(VI, from water has been investigated using a vegetable oil based emulsion liquid membrane (ELM technique. The main purpose of this study was to create a novel ELM formulation by choosing a more environmentally friendly and non-toxic diluent such as palm oil. The membrane phase so formulated includes the mobile carrier tri-n-octylmethylammonium chloride (TOMAC, to facilitate the metal transport, and the hydrophilic surfactant Tween 80 to facilitate the dispersion of the ELM phase in the aqueous solution. Span 80 is used as surfactant and butanol as co-surfactant. Our results demonstrate that this novel ELM formulation, using the vegetable palm oil as diluent, is useful for the removal of hexavalent chromium with an efficiency of over 99% and is thus competitive with the already existing, yet less environmentally friendly, ELM formulations. This result was achieved with an optimal concentration of 0.1 M NaOH as stripping agent and an external phase pH of 0.5. Different water qualities have also been investigated showing that the type of water (deionized, distilled, or tap water does not significantly influence the extraction rate.

  13. Aqueous liquid feed organic fuel cell using solid polymer electrolyte membrane

    Science.gov (United States)

    Surampudi, Subbarao (Inventor); Narayanan, Sekharipuram R. (Inventor); Vamos, Eugene (Inventor); Frank, Harvey A. (Inventor); Halpert, Gerald (Inventor); Olah, George A. (Inventor); Prakash, G. K. Surya (Inventor)

    1997-01-01

    A liquid organic fuel cell is provided which employs a solid electrolyte membrane. An organic fuel, such as a methanol/water mixture, is circulated past an anode of a cell while oxygen or air is circulated past a cathode of the cell. The cell solid electrolyte membrane is preferably fabricated from Nafion.TM.. Additionally, a method for improving the performance of carbon electrode structures for use in organic fuel cells is provided wherein a high surface-area carbon particle/Teflon.TM.-binder structure is immersed within a Nafion.TM./methanol bath to impregnate the electrode with Nafion.TM.. A method for fabricating an anode for use in a organic fuel cell is described wherein metal alloys are deposited onto the electrode in an electro-deposition solution containing perfluorooctanesulfonic acid. A fuel additive containing perfluorooctanesulfonic acid for use with fuel cells employing a sulfuric acid electrolyte is also disclosed. New organic fuels, namely, trimethoxymethane, dimethoxymethane, and trioxane are also described for use with either conventional or improved fuel cells.

  14. 49 CFR 173.201 - Non-bulk packagings for liquid hazardous materials in Packing Group I.

    Science.gov (United States)

    2010-10-01

    ... in Packing Group I. 173.201 Section 173.201 Transportation Other Regulations Relating to... materials in Packing Group I. (a) When § 172.101 of this subchapter specifies that a liquid hazardous... of part 173, to the requirements of part 178 of this subchapter at the Packing Group I...

  15. 49 CFR 173.202 - Non-bulk packagings for liquid hazardous materials in Packing Group II.

    Science.gov (United States)

    2010-10-01

    ... in Packing Group II. 173.202 Section 173.202 Transportation Other Regulations Relating to... materials in Packing Group II. (a) When § 172.101 of this subchapter specifies that a liquid hazardous... of part 173, to the requirements of part 178 of this subchapter at the Packing Group I or...

  16. 49 CFR 173.203 - Non-bulk packagings for liquid hazardous materials in Packing Group III.

    Science.gov (United States)

    2010-10-01

    ... in Packing Group III. 173.203 Section 173.203 Transportation Other Regulations Relating to... materials in Packing Group III. (a) When § 172.101 of this subchapter specifies that a liquid hazardous... of part 173, to the requirements of part 178 of this subchapter at the Packing Group I, II or...

  17. Improvement of Aconitum napellus micropropagation by liquid culture on floating membrane rafts.

    Science.gov (United States)

    Watad, A A; Kochba, M; Nissim, A; Gaba, V

    1995-03-01

    An efficient method was developed using floating membrane rafts (Liferaft(™)) for the micropropagation of Aconitum napellus (Ranunculaceae), a cut flower crop with a low natural propagation rate. This was achieved by introducing shoot tips into culture on Murashige and Skoog's (1962) solid medium, or liquid medium-supported rafts, supplemented by different levels of benzyl adenine (BA). Optimum shoot proliferation on solid medium required 4mg/l BA, whereas for expiants supported on rafts optimal proliferation was achieved at 0.25mg/l BA. Maximum shoot proliferation was found using the floating rafts (propagation ratio of 4.2 per month), 45% higher than the maximum value on solid medium. A similar value could be obtained on solid medium after a period of 2 months. The optimal response to BA was similar for fresh weight gain and shoot length. Growth in a shallow layer of liquid in shake flasks gives a similar shoot multiplication rate to that on floating rafts; however, submerged leaves brown and die.

  18. Ionic Liquids as the MOFs/Polymer Interfacial Binder for Efficient Membrane Separation.

    Science.gov (United States)

    Lin, Rijia; Ge, Lei; Diao, Hui; Rudolph, Victor; Zhu, Zhonghua

    2016-11-23

    Obtaining strong interfacial affinity between filler and polymer is critical to the preparation of mixed matrix membranes (MMMs) with high separation efficiency. However, it is still a challenge for micron-sized metal organic frameworks (MOFs) to achieve excellent compatibility and defect-free interface with polymer matrix. Thin layer of ionic liquid (IL) was immobilized on micron-sized HKUST-1 to eliminate the interfacial nonselective voids in MMMs with minimized free ionic liquid (IL) in polymer matrix, and then the obtained IL decorated HKUST-1 was incorporated into 4,4'-(hexafluoroisopropylidene)diphthalic anhydride-2,3,5,6-tetramethyl-1,3-phenyldiamine (6FDA-Durene) to fabricate MMMs. Acting as a filler/polymer interfacial binder, the favorable MOF/IL and IL/polymer interaction can facilitate the enhancement of MOF/polymer affinity. Compared to MMM with only HKUST-1 incorporation, MMM with IL decorated HKUST-1 succeeded in restricting the formation of nonselective interfacial voids, leading to an increment in CO2 selectivity. The IL decoration method can be an effective approach to eliminate interfacial voids in MMMs, extending the filler selection to a wide range of large-sized fillers.

  19. Increased productivity of Clostridium acetobutylicum fermentation of acetone, butanol, and ethanol by pervaporation through supported ionic liquid membrane

    NARCIS (Netherlands)

    Izak, P.; Schwarz, K.M.; Ruth, W.; Bahl, H.; Kragl, U.

    2008-01-01

    Pervaporation proved to be one of the best methods to remove solvents out of a solvent producing Clostridium acetobutylicum culture. By using an ionic liquid (IL)-polydimethylsiloxane (PDMS) ultrafiltration membrane (pore size 60 nm), we could guarantee high stability and selectivity during all meas

  20. Ionic-liquid-based proton conducting membranes for anhydrous H2/Cl2 fuel-cell applications.

    Science.gov (United States)

    Liu, Sa; Zhou, Li; Wang, Pengjie; Zhang, Fangfang; Yu, Shuchun; Shao, Zhigang; Yi, Baolian

    2014-03-12

    An ionic-liquid-doped poly(benzimidazole) (PBI) proton-conducting membrane for an anhydrous H2/Cl2 fuel cell has been proposed. Compared with other ionic liquids, such as imidazole-type ionic liquids, diethylmethylammonium trifluoromethanesulfonate ([dema][TfO]) showed better electrode reaction kinetics (H2 oxidation and Cl2 reduction reaction at platinum) and was more suitable for a H2/Cl2 fuel cell. PBI polymer and [dema][TfO] were compatible with each other, and the hybrid membranes exhibited high stability and good ionic conductivity, reaching 20.73 mS cm(-1) at 160 °C. We also analyzed the proton-transfer mechanism in this ionic-liquid-based membrane and considered that both proton-hopping and diffusion mechanisms existed. In addition, this composite electrolyte worked well in a H2/Cl2 fuel cell under non-water conditions. This work would give a good path to study the novel membranes for anhydrous H2/Cl2 fuel-cell application.

  1. Elucidation and identification of amino acid containing membrane lipids using liquid chromatography/high-resolution mass spectrometry

    NARCIS (Netherlands)

    Moore, E.K.; Hopmans, E.C.; Rijpstra, W.I.C.; Villanueva, L.; Sinninghe Damsté, J.S.

    2016-01-01

    RATIONALE: Intact polar lipids (IPLs) are the building blocks of cell membranes, and amino acid containing IPLs havebeen observed to be involved in response to changing environmental conditions in various species of bacteri a. High-performance liquid chromatography/mass spectrometry (HPLC/MS) has be

  2. Study of the kinetics of the transport of Cu(II), Cd(II) and Ni(II) ions through a liquid membrane

    Energy Technology Data Exchange (ETDEWEB)

    Granado-Castro, Maria D.; Galindo-Riano, Maria D.; Garcia-Vargas, M. [University of Cadiz, Department of Analytical Chemistry, Faculty of Sciences, Puerto Real, Cadiz (Spain); Dominguez-Lledo, F.C.; Diaz-Lopez, C. [University of La Havana, Department of Analytical Chemistry, Faculty of Chemistry, La Havana, CP (Cuba)

    2008-06-15

    The coupled transport of Cu(II), Cd(II) and Ni(II) ions through a bulk liquid membrane (BLM) containing pyridine-2-acetaldehyde benzoylhydrazone (2-APBH) as carrier dissolved in toluene has been studied. Once the optimal conditions of extraction of each metal were established, a comparative study of the transport kinetics for these metals was performed by means of a kinetic model involving two consecutive irreversible first-order reactions. The kinetic parameters apparent rate constants of the metal extraction and re-extraction reactions (k{sub 1}, k{sub 2}), the maximum reduced concentration of the metal in the liquid membrane (R{sup max}{sub o}), the time of the maximum value of R{sub o} (t{sub max}) and the maximum entry and exit fluxes of the metal through the liquid membrane (J{sup max}{sub f} and J{sup max}{sub s}) of the extraction and stripping reactions were evaluated and results showed good agreement between experimental data and theoretical predictions. Complete transport through the membrane took place according to the following order: Cd(II)>Cu(II)>Ni(II), with similar kinetic parameters obtained for Cu(II) and Cd(III). The transport behaviour of Ni(II) was different to that of Cu(II) and Cd(III), probably due to the different stoichiometry of the nickel complex compared to those of the other metal ions and the different chemical conditions required for its formation. The influence of the sample salinity on the transport kinetics was studied. k{sub 1} values decreased slightly when the feed solution salinity was increased for Cu(II) and Ni(II), but not for Cd(II). Values of k{sub 2} were practically unaffected. The proposed BLM was applied to the preconcentration and separation of metal ions (prior to their determination) in water samples with different saline matrices (CRM, river water and seawater), and good agreement with the certified values was obtained. (orig.)

  3. High temperature ceramic membrane reactors for coal liquid upgrading. Final report, September 21, 1989--November 20, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Tsotsis, T.T. [University of Southern California, Los Angeles, CA (United States). Dept. of Chemical Engineering; Liu, P.K.T. [Aluminum Co. of America, Pittsburgh, PA (United States); Webster, I.A. [Unocal Corp., Los Angeles, CA (United States)

    1992-12-31

    Membrane reactors are today finding extensive applications for gas and vapor phase catalytic reactions (see discussion in the introduction and recent reviews by Armor [92], Hsieh [93] and Tsotsis et al. [941]). There have not been any published reports, however, of their use in high pressure and temperature liquid-phase applications. The idea to apply membrane reactor technology to coal liquid upgrading has resulted from a series of experimental investigations by our group of petroleum and coal asphaltene transport through model membranes. Coal liquids contain polycyclic aromatic compounds, which not only present potential difficulties in upgrading, storage and coprocessing, but are also bioactive. Direct coal liquefaction is perceived today as a two-stage process, which involves a first stage of thermal (or catalytic) dissolution of coal, followed by a second stage, in which the resulting products of the first stage are catalytically upgraded. Even in the presence of hydrogen, the oil products of the second stage are thought to equilibrate with the heavier (asphaltenic and preasphaltenic) components found in the feedstream. The possibility exists for this smaller molecular fraction to recondense with the unreacted heavy components and form even heavier undesirable components like char and coke. One way to diminish these regressive reactions is to selectively remove these smaller molecular weight fractions once they are formed and prior to recondensation. This can, at least in principle, be accomplished through the use of high temperature membrane reactors, using ceramic membranes which are permselective for the desired products of the coal liquid upgrading process. An additional incentive to do so is in order to eliminate the further hydrogenation and hydrocracking of liquid products to undesirable light gases.

  4. Helfrich model of membrane bending: from Gibbs theory of liquid interfaces to membranes as thick anisotropic elastic layers.

    Science.gov (United States)

    Campelo, Felix; Arnarez, Clement; Marrink, Siewert J; Kozlov, Michael M

    2014-06-01

    Helfrich model of membrane bending elasticity has been most influential in establishment and development of Soft-Matter Physics of lipid bilayers and biological membranes. Recently, Helfrich theory has been extensively used in Cell Biology to understand the phenomena of shaping, fusion and fission of cellular membranes. The general background of Helfrich theory on the one hand, and the ways of specifying the model parameters on the other, are important for quantitative treatment of particular biologically relevant membrane phenomena. Here we present the origin of Helfrich model within the context of the general Gibbs theory of capillary interfaces, and review the strategies of computing the membrane elastic moduli based on considering a lipid monolayer as a three-dimensional thick layer characterized by trans-monolayer profiles of elastic parameters. We present the results of original computations of these profiles by a state-of-the-art numerical approach.

  5. 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.

  6. Determination of Edoxaban in Bulk and in Tablet Dosage Form by Stability Indicating High-Performance Liquid Chromatography

    Directory of Open Access Journals (Sweden)

    Pasam Satyanarayana Reddy , V. Shanmukha Kumar Jagarlapudi, Chandra Bala Sekaran

    2016-03-01

    Full Text Available Background: Edoxaban is an orally active direct factor Xa inhibitor. The aim of the present study was to develop a stability indicating HPLC method for the quantification of edoxaban in bulk and in tablet dosage form. Methods: Edoxaban was separated on Hypersil BDS C18 column (250 x 4.6 mm, i.d. 5µm using 0.1M K2HPO4: Methanol (65:35, v/v as an isocratic mobile phase at a flow rate of 1.0 ml/min. Detection was performed using photodiode array detector set at 245 nm. The chromatographic conditions were optimized. The method was validated as per the guidelines given by International Conference on Harmonization guidelines. Results: Edoxaban was eluted at 3.785 min with a total run time of 6 min. The calibration curve was found to be linear over the concentration range of 5–200 μg/ml. Limit of detection and limit of quantification for edoxaban are 0.209 µg/ml and 0.698 µg/ml, respectively. The intra- and inter-day precision values were ≤0.710% and the accuracy ranged from 99.824-100.720%. Besides, all the validation results were within acceptability criteria of general assay. The stability indicating nature of the method was established by subjecting the edoxaban to stress conditions such as acid and base hydrolyses, oxidative, photo- and thermal degradations. The degraded products formed in all stress conditions were resolved successfully from the edoxaban. Conclusion: The developed and validated method is suitable for the determination of edoxaban in bulk and in commercial tablet dosage form.

  7. Liquid-liquid-solid microextraction based on membrane-protected molecularly imprinted polymer fiber for trace analysis of triazines in complex aqueous samples.

    Science.gov (United States)

    Hu, Yuling; Wang, Yangyang; Hu, Yufei; Li, Gongke

    2009-11-20

    A novel liquid-liquid-solid microextraction (LLSME) technique based on porous membrane-protected molecularly imprinted polymer (MIP)-coated silica fiber has been developed. In this technique, a MIP-coated silica fiber was protected with a length of porous polypropylene hollow fiber membrane which was filled with water-immiscible organic phase. Subsequently the whole device was immersed into aqueous sample for extraction. The LLSME technique was a three-phase microextraction approach. The target analytes were firstly extracted from the aqueous sample through a few microliters of organic phase residing in the pores and lumen of the membrane, and were then finally extracted onto the MIP fiber. A terbutylazine MIP-coated silica fiber was adopted as an example to demonstrate the feasibility of the novel LLSME method. The extraction parameters such as the organic solvent, extraction and desorption time were investigated. Comparison of the LLSME technique was made with molecularly imprinted polymer based solid-phase microextraction (MIP-SPME) and hollow fiber membrane-based liquid-phase microextraction (HF-LPME), respectively. The LLSME, integrating the advantages of high selectivity of MIP-SPME and enrichment and sample cleanup capability of the HF-LPME into a single device, is a promising sample preparation method for complex samples. Moreover, the new technique overcomes the problem of disturbance from water when the MIP-SPME fiber was exposed directly to aqueous samples. Applications to analysis of triazine herbicides in sludge water, watermelon, milk and urine samples were evaluated to access the real sample application of the LLSME method by coupling with high-performance liquid chromatography (HPLC). Low limits of detection (0.006-0.02 microg L(-1)), satisfactory recoveries and good repeatability for real sample (RSD 1.2-9.6%, n = 5) were obtained. The method was demonstrated to be a fast, selective and sensitive pretreatment method for trace analysis of triazines

  8. Liquid -to-glass transition in bulk glass-forming Cu55-xZr45Agx alloys using molecular dynamic simulations

    Directory of Open Access Journals (Sweden)

    Celtek M.

    2011-05-01

    Full Text Available We report results from molecular dynamics (MD studies concerning the microscopic structure of the ternary, bulk metallic glass-forming Cu55-x Zr45Agx (x=0,10,20 alloys using tight-binding potentials. Understanding of the nature of Glass Forming Ability (GFA of studied alloys, GFA parameters, glass transition temperature (T-g, melting temperature (T-m, reduced glass transition temperature (T-g/T-m, the supercooled liquid region and other parameters were simulated and compared with experiments. The computed pair distribution functions reproduce well experimental x-ray data of Inoue and co-workers. Structure analysis of the Cu-Zr-Ag alloy based on MD simulation will be also presented

  9. A Mechanistic Study of Chemically Modified Inorganic Membranes for Gas and Liquid Separations

    Energy Technology Data Exchange (ETDEWEB)

    Way, J Douglas

    2011-01-21

    This final report will summarize the progress made during the period August 1, 1993 - October 31, 2010 with support from DOE grant number DE-FG03-93ER14363. The objectives of the research have been to investigate the transport mechanisms in micro- and mesoporous, metal oxide membranes and to examine the relationship between the microstructure of the membrane, the membrane surface chemistry, and the separation performance of the membrane. Examples of the membrane materials under investigation are the microporous silica hollow fiber membrane manufactured by PPG Industries, chemically modified mesoporous oxide membranes, and polymer membranes containing microporous oxides (mixed matrix membranes). Analytical techniques such as NMR, FTIR and Raman spectroscopy, thermal analysis, and gas adsorption were used to investigate membrane microstructure and to probe the chemical interactions occurring at the gas-membrane interface.

  10. Microcontact Printing of Thiol-Functionalized Ionic Liquid Microarrays for "Membrane-less" and "Spill-less" Gas Sensors.

    Science.gov (United States)

    Gondosiswanto, Richard; Gunawan, Christian A; Hibbert, David B; Harper, Jason B; Zhao, Chuan

    2016-11-16

    Lab-on-a-chip systems have gained significant interest for both chemical synthesis and assays at the micro-to-nanoscale with a unique set of benefits. However, solvent volatility represents one of the major hurdles to the reliability and reproducibility of the lab-on-a-chip devices for large-scale applications. Here we demonstrate a strategy of combining nonvolatile and functionalized ionic liquids with microcontact printing for fabrication of "wall-less" microreactors and microfluidics with high reproducibility and high throughput. A range of thiol-functionalized ionic liquids have been synthesized and used as inks for microcontact printing of ionic liquid microdroplet arrays onto gold chips. The covalent bonds formed between the thiol-functionalized ionic liquids and the gold substrate offer enhanced stability of the ionic liquid microdroplets, compared to conventional nonfunctionalized ionic liquids, and these microdroplets remain stable in a range of nonpolar and polar solvents, including water. We further demonstrate the use of these open ionic liquid microarrays for fabrication of "membrane-less" and "spill-less" gas sensors with enhanced reproducibility and robustness. Ionic-liquid-based microarray and microfluidics fabricated using the described microcontact printing may provide a versatile platform for a diverse number of applications at scale.

  11. IR and SFG vibrational spectroscopy of the water bend in the bulk liquid and at the liquid-vapor interface, respectively

    Energy Technology Data Exchange (ETDEWEB)

    Ni, Yicun; Skinner, J. L. [Theoretical Chemistry Institute and Department of Chemistry, University of Wisconsin, Madison, Wisconsin 53706 (United States)

    2015-07-07

    Vibrational spectroscopy of the water bending mode has been investigated experimentally to study the structure of water in condensed phases. In the present work, we calculate the theoretical infrared (IR) and sum-frequency generation (SFG) spectra of the HOH bend in liquid water and at the water liquid/vapor interface using a mixed quantum/classical approach. Classical molecular dynamics simulation is performed by using a recently developed water model that explicitly includes three-body interactions and yields a better description of the water surface. Ab-initio-based transition frequency, dipole, polarizability, and intermolecular coupling maps are developed for the spectral calculations. The calculated IR and SFG spectra show good agreement with the experimental measurements. In the theoretical imaginary part of the SFG susceptibility for the water liquid/vapor interface, we find two features: a negative band centered at 1615 cm{sup −1} and a positive band centered at 1670 cm{sup −1}. We analyze this spectrum in terms of the contributions from molecules in different hydrogen-bond classes to the SFG spectral density and also compare to SFG results for the OH stretch. SFG of the water bending mode provides a complementary picture of the heterogeneous hydrogen-bond configurations at the water surface.

  12. IR and SFG vibrational spectroscopy of the water bend in the bulk liquid and at the liquid-vapor interface, respectively.

    Science.gov (United States)

    Ni, Yicun; Skinner, J L

    2015-07-07

    Vibrational spectroscopy of the water bending mode has been investigated experimentally to study the structure of water in condensed phases. In the present work, we calculate the theoretical infrared (IR) and sum-frequency generation (SFG) spectra of the HOH bend in liquid water and at the water liquid/vapor interface using a mixed quantum/classical approach. Classical molecular dynamics simulation is performed by using a recently developed water model that explicitly includes three-body interactions and yields a better description of the water surface. Ab-initio-based transition frequency, dipole, polarizability, and intermolecular coupling maps are developed for the spectral calculations. The calculated IR and SFG spectra show good agreement with the experimental measurements. In the theoretical imaginary part of the SFG susceptibility for the water liquid/vapor interface, we find two features: a negative band centered at 1615 cm(-1) and a positive band centered at 1670 cm(-1). We analyze this spectrum in terms of the contributions from molecules in different hydrogen-bond classes to the SFG spectral density and also compare to SFG results for the OH stretch. SFG of the water bending mode provides a complementary picture of the heterogeneous hydrogen-bond configurations at the water surface.

  13. Voltammetry of ion transfer across a polarized room-temperature ionic liquid membrane facilitated by valinomycin: theoretical aspects and application.

    Science.gov (United States)

    Langmaier, Jan; Samec, Zdenek

    2009-08-01

    Cyclic voltammetry is used to investigate the transfer of alkali-metal cations, protons, and ammonium ions facilitated by the complex formation with valinomycin at the interface between an aqueous electrolyte solution and a room-temperature ionic liquid (RTIL) membrane. The membrane is made of a thin (approximately 112 microm) microporous filter impregnated with an RTIL that is composed of tridodecylmethylammonium cations and tetrakis[3,5-bis(trifluoromethyl)phenyl]borate anions. An extension of the existing theory of voltammetry of ion transfer across polarized liquid membranes makes it possible to evaluate the standard ion-transfer potentials for the hydrophilic cations studied, as well as the stability constants (K(i)) of their 1:1 complexes with valinomycin, as log K(i) = 9.0 (H(+)), 11.1 (Li(+)), 12.8 (Na(+)), 17.2 (K(+)), 15.7 (Rb(+)), 15.1 (Cs(+)), and 14.7 (NH(4)(+)). These data point to the remarkably enhanced stability of the valinomycin complexes within RTIL, and to the enhanced selectivity of valinomycin for K(+) over all other univalent ions studied, compared to the conventional K(+) ion-selective liquid-membrane electrodes. Selective complex formation allows one to resolve voltammetric responses of K(+) and Na(+) in the presence of an excess of Mg(2+) or Ca(2+), which is demonstrated by determination of K(+) and Na(+) in the table and tap water samples.

  14. 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)

  15. Analysis of Nabumetone in Bulk and Tablet Formulation by a New and Validated Reverse Phase High Performance Liquid Chromatography

    Directory of Open Access Journals (Sweden)

    Prafulla Kumar Sahu

    2009-01-01

    Full Text Available RP-HPLC analytical method for the estimation of nabumetone in pharmaceutical dosage forms was developed and validated. A Hypersil ODS C18, 4.6 mm x 250 mm, 5 μm column from Supelco (India, with mobile phase comprised of acetonitrile: triple distilled water (50:50 with a total run time of 18 min was used and the wavelength of the detector was set at 230 nm. Stavudin is used as internal standard. The retention times were 14.167 min and 1.967 min for nabumetone and stavudin (IS respectively. The extraction recovery of nabumetone from pharmaceutical dosage form (tablets was >101% and the calibration curve was linear (r2 = 0.995 over nabumetone concentrations ranging from 1 to 200 µg/mL. The method had an accuracy of >99% and LOD and LOQ of 0.17482 µg/mL and 0.5827 µg/mL respectively. The method reported is simple, reliable, precise and accurate and has the capability of being used for determination of nabumetone in bulk and pharmaceutical dosage forms.

  16. Study on supported combined liquid membrane containing HEH(EH)P and HNO_3 for trivalent gadolinium transfer

    Institute of Scientific and Technical Information of China (English)

    Liang Pei; Li Ming Wang

    2011-01-01

    A novel kind of supported combined liquid membrane (SCLM) has been studied for the Gd(Ⅲ) transfer. SCLM contained polyvinylidene fluoride membrane (PVDF) as the liquid membrane support and renewal solution including HNO3 solution as the stripping solution and 2-ethyl hexyl phosphonic acid-mono-2-ethyl hexyl ester (HEH(EH)P) as the carrier dissolved in kerosene. The mixed solution of carrier and kerosene was membrane solution. The optimum transport conditions of Gd(Ⅲ) were that concentration of HNO3 solution was 4.00 mol/L, concentration of carrier was 0.16 mol/L, and volume ratio of membrane solution to stripping solution was 30:30 of the renewal phase, and pH value was 4.80 of the feed phase. Under the optimum condition studied, when initial concentration of Gd(Ⅲ) was 1.00 × 10-4 mol/L, the transfer rate of Gd(Ⅲ) was 96.8% during 130 min.

  17. Relationship between the Contents of MDA, the Activity of SOD in Serum of the Milk Goat with Fluorosis and the Erythrocytic Membrane Liquidity

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    To research the relation among the erythrooytic membrane liquidity and the contents of MPA, the activity of SOD in serum of the milk goat with fluorosis. An animal model with fluorosia was constructed, and the fluorescent probe technique of DPH was used to measue the erythrocytic membrane liquidity. At the same time, the contents of MPA and the activity of SOD in serum were measured. The results showed that the erythrocytic membrane liquidity in the control group and flurosis group were 5.6742 ± 0.4417 and 3.7248 ± 0.4521 (P <0.01) respectively, the contents of MPA in serum were 2.0408 ± 0.198 and 4.494± 0.438 (P <0.01) respectively, the activities of SOD were 175.638 ± 22.201 and 113.714 ± 34.258 (P <0.01) respectively. The correlation analysis indicated that the relation between the activity of SOD and the liquidity of erythrocytic membrane was positive correlation ( r=0.7321, P <0.05), whereas the relation between the contents of MPA and the liquidity of erythrocytic membrane was negative correlation (r = -0.6438, P <0.01). The erythrocytio membrane liquidity decreased in milk goat with fluorosis, which played a role in the occurrence and development of the fluorosis. There was correlation among the erythrocytic membrane liquidity and the contents of MDA, the activity of SOD.

  18. Design of Phosphonated Imidazolium-Based Ionic Liquids Grafted on γ-Alumina: Potential Model for Hybrid Membranes.

    Science.gov (United States)

    Pizzoccaro, Marie-Alix; Drobek, Martin; Petit, Eddy; Guerrero, Gilles; Hesemann, Peter; Julbe, Anne

    2016-07-27

    Imidazolium bromide-based ionic liquids bearing phosphonyl groups on the cationic part were synthesized and grafted on γ-alumina (γ-Al₂O₃) powders. These powders were prepared as companion samples of conventional mesoporous γ-alumina membranes, in order to favor a possible transfer of the results to supported membrane materials, which could be used for CO₂ separation applications. Effective grafting was demonstrated using energy dispersive X-ray spectrometry (EDX), N₂ adsorption measurements, fourier transform infrared spectroscopy (FTIR), and special attention was paid to (31)P and (13)C solid state nuclear magnetic resonance spectroscopy (NMR).

  19. Determination of oxytetracycline in milk samples by polymer inclusion membrane separation coupled to high performance liquid chromatography.

    Science.gov (United States)

    Pérez-Silva, Irma; Rodríguez, José A; Ramírez-Silva, Ma Teresa; Páez-Hernández, Ma Elena

    2012-03-09

    The determination of oxytetracycline in milk samples using a polymer inclusion membrane concept with high performance liquid chromatography (HPLC) was studied. The membranes developed are composed by cellulose acetate as polymer base, Cyanex 923 as carrier and o-nitrophenyl octyl ether as plasticizer. In the optimal conditions, the method exhibits good linearity in the range 0.03-0.20 mg L(-1) with a limit of detection and quantification of 8.2 and 27.3 μg L(-1) respectively. The method was successfully applied to the analysis of milk samples with high selectivity.

  20. Design of Phosphonated Imidazolium-Based Ionic Liquids Grafted on γ-Alumina: Potential Model for Hybrid Membranes

    Science.gov (United States)

    Pizzoccaro, Marie-Alix; Drobek, Martin; Petit, Eddy; Guerrero, Gilles; Hesemann, Peter; Julbe, Anne

    2016-01-01

    Imidazolium bromide-based ionic liquids bearing phosphonyl groups on the cationic part were synthesized and grafted on γ-alumina (γ-Al2O3) powders. These powders were prepared as companion samples of conventional mesoporous γ-alumina membranes, in order to favor a possible transfer of the results to supported membrane materials, which could be used for CO2 separation applications. Effective grafting was demonstrated using energy dispersive X-ray spectrometry (EDX), N2 adsorption measurements, fourier transform infrared spectroscopy (FTIR), and special attention was paid to 31P and 13C solid state nuclear magnetic resonance spectroscopy (NMR). PMID:27472321

  1. Design of Phosphonated Imidazolium-Based Ionic Liquids Grafted on γ-Alumina: Potential Model for Hybrid Membranes

    Directory of Open Access Journals (Sweden)

    Marie-Alix Pizzoccaro

    2016-07-01

    Full Text Available Imidazolium bromide-based ionic liquids bearing phosphonyl groups on the cationic part were synthesized and grafted on γ-alumina (γ-Al2O3 powders. These powders were prepared as companion samples of conventional mesoporous γ-alumina membranes, in order to favor a possible transfer of the results to supported membrane materials, which could be used for CO2 separation applications. Effective grafting was demonstrated using energy dispersive X-ray spectrometry (EDX, N2 adsorption measurements, fourier transform infrared spectroscopy (FTIR, and special attention was paid to 31P and 13C solid state nuclear magnetic resonance spectroscopy (NMR.

  2. Oxide or carbide nanoparticles synthesized by laser ablation of a bulk Hf target in liquids and their structural, optical, and dielectric properties

    Science.gov (United States)

    Semaltianos, N. G.; Friedt, J.-M.; Chassagnon, R.; Moutarlier, V.; Blondeau-Patissier, V.; Combe, G.; Assoul, M.; Monteil, G.

    2016-05-01

    Laser ablation of a bulk Hf target in deionized (DI) water, ethanol, or toluene was carried out for the production of nanoparticles' colloidal solutions. Due to the interaction of the ablation plasma plume species with the species which are produced by the liquid decomposition at the plume-liquid interface, hafnia (HfO2) nanoparticles are synthesized in DI water, hafnium carbide (HfC) nanoparticles in toluene, and a mixture of these in ethanol. The hafnia nanoparticles are in the monoclinic low temperature phase and in the tetragonal and fcc high temperature phases. Their size distribution follows log-normal function with a median diameter in the range of 4.3-5.3 nm. Nanoparticles synthesized in DI water have band gaps of 5.6 and 5.4 eV, in ethanol 5.72 and 5.65 eV (using low and high pulse energy), and in toluene 3 eV. The values for the relative permittivity in the range of 7.74-8.90 were measured for hafnia nanoparticles' thin films deposited on substrates by drop-casting (self-assembled layers) in parallel plate capacitor structures.

  3. Alkaline stability of quaternary ammonium cations for alkaline fuel cell membranes and ionic liquids.

    Science.gov (United States)

    Marino, M G; Kreuer, K D

    2015-02-01

    The alkaline stability of 26 different quaternary ammonium groups (QA) is investigated for temperatures up to 160 °C and NaOH concentrations up to 10 mol L(-1) with the aim to provide a basis for the selection of functional groups for hydroxide exchange membranes in alkaline fuel cells and of ionic-liquid cations stable in basic conditions. Most QAs exhibit unexpectedly high alkaline stability with the exception of aromatic cations. β-Protons are found to be far less susceptible to nucleophilic attack than previously suggested, whereas the presence of benzyl groups, nearby hetero-atoms, or other electron-withdrawing species promote degradation reactions significantly. Cyclic QAs proved to be exceptionally stable, with the piperidine-based 6-azonia-spiro[5.5]undecane featuring the highest half-life at the chosen conditions. Absolute and relative stabilities presented herein stand in contrast to literature data, the differences being ascribed to solvent effects on degradation.

  4. Optimization of cyanide extraction from wastewater using emulsion liquid membrane system by response surface methodology.

    Science.gov (United States)

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

    To solve the disposal problem of cyanide wastewater, removal of cyanide from wastewater using a water-in-oil emulsion type of emulsion liquid membrane (ELM) was studied in this work. Specifically, the effects of surfactant Span-80, carrier trioctylamine (TOA), stripping agent NaOH solution and the emulsion-to-external-phase-volume ratio on removal of cyanide were investigated. Removal of total cyanide was determined using the silver nitrate titration method. Regression analysis and optimization of the conditions were conducted using the Design-Expert software and response surface methodology (RSM). The actual cyanide removals and the removals predicted using RSM analysis were in close agreement, and the optimal conditions were determined to be as follows: the volume fraction of Span-80, 4% (v/v); the volume fraction of TOA, 4% (v/v); the concentration of NaOH, 1% (w/v); and the emulsion-to-external-phase volume ratio, 1:7. Under the optimum conditions, the removal of total cyanide was 95.07%, and the RSM predicted removal was 94.90%, with a small exception. The treatment of cyanide wastewater using an ELM is an effective technique for application in industry.

  5. DEVELOPMENT AND SELECTION OF IONIC LIQUID ELECTROLYTES FOR HYDROXIDE CONDUCTING POLYBENZIMIDAZOLE MEMBRANES IN ALKALINE FUEL CELLS

    Energy Technology Data Exchange (ETDEWEB)

    Fox, E.

    2012-05-01

    Alkaline fuel cell (AFC) operation is currently limited to specialty applications such as low temperatures and pure HO due to the corrosive nature of the electrolyte and formation of carbonates. AFCs are the cheapest and potentially most efficient (approaching 70%) fuel cells. The fact that non-Pt catalysts can be used, makes them an ideal low cost alternative for power production. The anode and cathode are separated by and solid electrolyte or alkaline porous media saturated with KOH. However, CO from the atmosphere or fuel feed severely poisons the electrolyte by forming insoluble carbonates. The corrosivity of KOH (electrolyte) limits operating temperatures to no more than 80°C. This chapter examines the development of ionic liquids electrolytes that are less corrosive, have higher operating temperatures, do not chemically bond to CO and enable alternative fuels. Work is detailed on the IL selection and characterization as well as casting methods within the polybenzimidazole based solid membrane. This approach is novel as it targets the root of the problem (the electrolyte) unlike other current work in alkaline fuel cells which focus on making the fuel cell components more durable.

  6. Stability-indicating liquid chromatographic method for quantification of new anti-epileptic drug lacosamide in bulk and pharmaceutical formulation

    Directory of Open Access Journals (Sweden)

    Chhalotiya Usmangani K.

    2012-01-01

    Full Text Available An isocratic stability indicating reversed-phase liquid chromatographic determination was developed for the quantitative determination of lacosamide in the pharmaceutical dosage form. A Hypersil C-18, 4.5μm column with mobile phase containing acetonitrile-water (20:80, v/v was used. The flow rate was 1.0 mL min-1 and effluents were monitored at 258 nm. The retention time of lacosamide was 8.9 min. The method was found to be linear in the concentration range of 5-100 μg/ml and the recovery was found to be in the range of 99.15 - 100.09 %. The limit of detection and limit of quantification were found to be 2 μg/ml and 5 μg/ml, respectively. Lacosamide stock solutions were subjected to acid and alkali hydrolysis, chemical oxidation and dry heat degradation. The drug was found to be stable to the dry heat and acidic condition attempted. The proposed method was validated and successfully applied to the estimation of lacosamide in tablet dosage forms.

  7. Study on the liquid membrane oscillation of water/oil/water system containing TTAB and picric acid

    Institute of Scientific and Technical Information of China (English)

    Li Zhou; Jiao Ning Tang; Bo Liu; Yi Guang Wu; Ai Lian Wang; Chuan Dong Liao

    2008-01-01

    The liquid membrane oscillation of a novel water (aqueous tetradecyl trimethyl ammoniumbromide,TTAB and alcohol sohition)/oil (picdcacid in chloroform sohition)/water (aqueous glucose solution) system was investigated.By using homemade device,the curves of various liquid membranes oscillation with different concentration of TTAB and picric acid,types of alcohol and other organic solvents at different temperature were measured.The results show that the water (aqueous 7 mmol/L of TTAB and 0.5 mol/L of n-propanol solution)/oil (0.5 mmol/L of picric acid in chloroform solution)/water (aqueous glucose solution) system performed sustained and stable oscillation at 30℃.And the novel system can recognise added amino acid.

  8. Liquid-liquid electro-organo-synthetic processes in a carbon nanofibre membrane microreactor: Triple phase boundary effects in the absence of intentionally added electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Watkins, John D.; Ahn, Sunyhik D.; Taylor, James E.; Bull, Steven D. [Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY (United Kingdom); Bulman-Page, Philip C. [School of Chemistry, University of East Anglia, Norwich, Norfolk NR4 7TJ (United Kingdom); Marken, Frank, E-mail: F.Marken@bath.ac.uk [Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY (United Kingdom)

    2011-07-30

    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 {mu}m 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{sup -5} m s{sup -1} and electrolysis of typically 1 mg n-butylferrocene in a 100 {mu}L volume. For the two-electron reduction of tetraethyl-ethylenetetracarboxylate the apparent mass transfer coefficient m = 4 x 10{sup -6} m s{sup -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 {mu}L volume is demonstrated. Deuterated products are formed in the presence of D{sub 2}O electrolyte media. The triple phase boundary dominated mechanism and future microreactor design improvements are discussed.

  9. New types of Brönsted acid-base ionic liquids-based membranes for applications in PEMFCs.

    Science.gov (United States)

    Fernicola, Alessandra; Panero, Stefania; Scrosati, Bruno; Tamada, Masahiro; Ohno, Hiroyuki

    2007-05-14

    A series of ionic liquids (ILs) are prepared by neutralizing tertiary amines with N,N-bis(trifluoromethanesulfonyl)imide (HTFSI). As demonstrated by thermal and electrochemical characterizations, these ILs have very good temperature stability and a high ionic conductivity, that is, of the order of 10(-2) S cm-1. By incorporating these ILs into a poly(vinylidenfluoride-co-hexafluoropropylene) polymer matrix, membranes with a high melting temperature, high decomposition point and with an ionic conductivity of about 10(-2) S cm-1 at 140 degrees C, are obtained. These IL-based, proton-conducting membranes are proposed as new polymer electrolytes for high-temperature polymer electrolyte membrane fuel cells (PEMFCs).

  10. Analysis and quantification of parabens in cosmetic products by utilizing hollow fibre-supported liquid membrane and high performance liquid chromatography with ultraviolet detection.

    Science.gov (United States)

    Msagati, T A M; Barri, T; Larsson, N; Jönsson, J A

    2008-08-01

    A simple and direct method based on hollow fibre-supported liquid membrane (HFSLM) extraction and liquid chromatography equipped with a UV detector was developed for analysis and quantification of parabens in cosmetic products. The parabens analysed included methyl, ethyl, propyl, isobutyl and butyl paraben. The HFSLM extraction was carried out by employing di-n-hexyl ether as organic liquid that was immobilized in the hollow fibre membrane. The HFSLM extraction is simple, cheap, minimizes the use of solvents and uses disposable material. In an investigation of 11 paraben-containing cosmetic products, the levels of parabens (sum of all parabens in a product) ranged from 0.43% to 0.79% (w/w) for skin care products, 0.07-0.44% for hair fixing gels and 0.30-0.52% for soap solutions. The levels of individual parabens in individual cosmetic products ranged between 0.03% and 0.42% w/w for skin care products, 0.07% and 0.26% w/w for hair fixing gels and between 0.11% and 0.34% w/w for soap solutions. Parabens were found in the highest concentrations in skin care products followed by soap solutions and the least amounts were found in hair fixing gels. Of the paraben-containing products tested, all of them contained methyl paraben and about 90% contained propyl paraben in addition to methyl paraben. One product contained all the parabens analysed.

  11. Liquid crystals and their interactions with colloidal particles and phospholipid membranes: Molecular simulation studies

    Science.gov (United States)

    Kim, Evelina B.

    Experimentally, liquid crystals (LC) can be used as the basis for optical biomolecular sensors that rely on LC ordering. Recently, the use of LC as a reporting medium has been extended to investigations of molecular scale processes at lipid laden aqueous-LC interfaces and at biological cell membranes. In this thesis, we present two related studies where liquid crystals are modelled at different length scales. We examine (a) the behavior of nanoscopic colloidal particles in LC systems, using Monte Carlo (MC) molecular simulations and a mesoscopic dynamic field theory (DyFT); and (b) specific interactions of two types of mesogens with a model phospholipid bilayer, using atomistic molecular dynamics (MD) at the A-nm scale. In (a), we consider colloidal particles suspended in a LC, confined between two walls. We calculate the colloid-substrate and colloid-colloid potentials of mean force (PMF). For the MC simulations, we developed a new technique (ExEDOS or Expanded Ensemble Density Of States) that ensures good sampling of phase space without prior knowledge of the energy landscape of the system. Both results, simulation and DyFT, indicate a repulsive force acting between a colloid and a wall. In contrast, both techniques indicate an overall colloid-colloid attraction and predict a new topology of the disclination lines that arises when the particles approach each other. In (b), we find that mesogens (pentylcyanobiphenyl [5CB] or difluorophenyl-pentylbicyclohexyl [5CF]) preferentially partition from the aqueous phase into a dipalmitoylphosphatidylcholine (DPPC) bilayer. We find highly favorable free energy differences for partitioning (-18kBT for 5CB, -26k BT for 5CF). We also simulated fully hydrated bilayers with embedded 5CB or 5CF at concentrations used in recent experiments (6 mol% and 20 mol%). The presence of mesogens in the bilayer enhances the order of lipid acyl tails and changes the spatial and orientational arrangement of lipid headgroup atoms. A stronger

  12. Novel Ceramic-Polymer Composite Membranes for the Separation of Hazardous Liquid Waste

    Energy Technology Data Exchange (ETDEWEB)

    Yoram Cohen

    2001-12-01

    The present project was conceived to address the need for robust yet selective membranes suitable for operating in harsh ph, solvent, and temperature environments. An important goal of the project was to develop a membrane chemical modification technology that would allow one to tailor-design membranes for targeted separation tasks. The method developed in the present study is based on the process of surface graft polymerization. Using essentially the same base technology of surface modification the research was aimed at demonstrating that improved membranes can be designed for both pervaporation separation and ultrafiltration. In the case of pervaporation, the present study was the first to demonstrate that pervaporation can be achieved with ceramic support membranes modified with an essentially molecular layer of terminally anchored polymer chains. The main advantage of the above approach, relative to other proposed membranes, is that the separating polymer layer is covalently attached to the ceramic support. Therefore, such membranes have a potential use in organic-organic separations where the polymer can swell significantly yet membrane robustness is maintained due to the chemical linkage of the chains to be inorganic support. The above membrane technology was also useful in developing fouling resistant ultrafiltration membranes. The prototype membrane developed in the project was evaluated for the treatment of oil-in-water microemulsions, demonstrating lack of irreversible fouling common with commercial membranes.

  13. Performance Validation and Scaling of a Capillary Membrane Solid-Liquid Separation System

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, S; Cook, J; Juratovac, J; Goodwillie, J; Burke, T

    2011-10-25

    Algaeventure Systems (AVS) has previously demonstrated an innovative technology for dewatering algae slurries that dramatically reduces energy consumption by utilizing surface physics and capillary action. Funded by a $6M ARPA-E award, transforming the original Harvesting, Dewatering and Drying (HDD) prototype machine into a commercially viable technology has required significant attention to material performance, integration of sensors and control systems, and especially addressing scaling issues that would allow processing extreme volumes of algal cultivation media/slurry. Decoupling the harvesting, dewatering and drying processes, and addressing the rate limiting steps for each of the individual steps has allowed for the development individual technologies that may be tailored to the specific needs of various cultivation systems. The primary performance metric used by AVS to assess the economic viability of its Solid-Liquid Separation (SLS) dewatering technology is algae mass production rate as a function of power consumption (cost), cake solids/moisture content, and solids capture efficiency. An associated secondary performance metric is algae mass loading rate which is dependent on hydraulic loading rate, area-specific hydraulic processing capacity (gpm/in2), filter:capillary belt contact area, and influent algae concentration. The system is capable of dewatering 4 g/L (0.4%) algae streams to solids concentrations up to 30% with capture efficiencies of 80+%, however mass production is highly dependent on average cell size (which determines filter mesh size and percent open area). This paper will present data detailing the scaling efforts to date. Characterization and performance data for novel membranes, as well as optimization of off-the-shelf filter materials will be examined. Third party validation from Ohio University on performance and operating cost, as well as design modification suggestions will be discussed. Extrapolation of current productivities

  14. Bulk derivatization and cation exchange restricted access media-based trap-and-elute liquid chromatography–mass spectrometry method for determination of trace estrogens in serum

    Energy Technology Data Exchange (ETDEWEB)

    Beinhauer, Jana [Department of Biochemistry, Faculty of Science, Palacký University, Šlechtitelů 11, CZ-783 71 Olomouc (Czech Republic); Centre of the Region Haná for Biotechnological and Agricultural Research - Department of Protein Biochemistry and Proteomics, Faculty of Science, Palacký University, Šlechtitelů 11, CZ-783 71 Olomouc (Czech Republic); Bian, Liangqiao [Shimadzu Center for Advanced Analytical Chemistry, The University of Texas at Arlington, Arlington, TX (United States); Shimadzu Institute for Research Technologies, The University of Texas at Arlington, Arlington, TX (United States); Fan, Hui [Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, TX (United States); Šebela, Marek [Department of Biochemistry, Faculty of Science, Palacký University, Šlechtitelů 11, CZ-783 71 Olomouc (Czech Republic); Centre of the Region Haná for Biotechnological and Agricultural Research - Department of Protein Biochemistry and Proteomics, Faculty of Science, Palacký University, Šlechtitelů 11, CZ-783 71 Olomouc (Czech Republic); Kukula, Maciej [Shimadzu Center for Advanced Analytical Chemistry, The University of Texas at Arlington, Arlington, TX (United States); Shimadzu Institute for Research Technologies, The University of Texas at Arlington, Arlington, TX (United States); Barrera, Jose A. [Shimadzu Institute for Research Technologies, The University of Texas at Arlington, Arlington, TX (United States); and others

    2015-02-09

    Highlights: • Analysis of estrogens in small volume samples at low parts-per-trillion concentration. • Charged bulk derivatization facilitates on-line ion exchange sample preparation. • On-line WCX restricted access media traps analytes, but not proteins and lipids. • Complete preparation and LC–MS/MS analysis completed in 30 min/sample. - Abstract: Estrone (E1), estradiols (α/β-E2), and estriol (E3) are four major metabolically active estrogens exerting strong biological activities at very low circulating concentrations. This paper reports a sensitive and efficient method with automated, on-line clean-up and detection to determine trace estrogens in a small volume of serum samples using liquid chromatography–electrospray ionization–tandem mass spectrometry directly, without off-line liquid–liquid or solid-phase extraction pretreatments. Serum aliquots (charcoal stripped fetal bovine serum, 100 μL) were spiked with four estrogen standards and their corresponding isotope-labeled internal standards, then bulk derivatized with 2-fluoro-1-methyl-pyridium p-toluenesulfonate (2-FMP) to establish the calibration curves and perform method validation. Calibration was established in the concentration ranges of 5–1000 pg mL{sup −1}, and demonstrated good linearity of R{sup 2} from 0.9944 to 0.9997 for the four derivatized estrogens. The lower detection limits obtained were 3–7 pg mL{sup −1}. Good accuracy and precision in the range of 86–112% and 2.3–11.9%, respectively, were observed for the quality control (QC) samples at low, medium, and high concentration levels. The stability tests showed that the derivatized serum samples were stable 8 h after derivatization at room temperature and at least to 48 h if stored at −20 °C. The method was applied to measure trace estrogens in real human and bovine serum samples, and three of four estrogen compounds studied were observed and quantified.

  15. Novel analytical procedure using a combination of hollow fiber supported liquid membrane and dispersive liquid-liquid microextraction for the determination of aflatoxins in soybean juice by high performance liquid chromatography - Fluorescence detector.

    Science.gov (United States)

    Simão, Vanessa; Merib, Josias; Dias, Adriana N; Carasek, Eduardo

    2016-04-01

    This study describes a combination between hollow fiber membrane and dispersive liquid-liquid microextraction for determination of aflatoxins in soybean juice by HPLC. The main advantage of this approach is the use of non-chlorinated solvent and small amounts of organic solvents. The optimum extraction conditions were 1-octanol as immobilized solvent; toluene and acetone at 1:5 ratio as extraction and disperser solvents (100 μL), NaCl at 2% of the sample volume and extraction time of 60 min. The optimal condition for the liquid desorption was 150 μL acetonitrile:water (50:50 v/v) and desorption time of 20 min. The linear range varied from 0.03 to 21 μg L(-1), with R(2) coefficients ranging from 0.9940 to 0.9995. The limits of detection and quantification ranged from 0.01 μg L(-1) to 0.03 μg L(-1) and from 0.03 μg L(-1) to 0.1 μg L(-1), respectively. Recovery tests ranged from 72% to 117% and accuracy between 12% and 18%.

  16. Exploiting the Phenomenon of Liquid-Liquid Phase Separation for Enhanced and Sustained Membrane Transport of a Poorly Water-Soluble Drug.

    Science.gov (United States)

    Indulkar, Anura S; Gao, Yi; Raina, Shweta A; Zhang, Geoff G Z; Taylor, Lynne S

    2016-06-01

    Recent studies on aqueous supersaturated lipophilic drug solutions prepared by methods including antisolvent addition, pH swing, or dissolution of amorphous solid dispersions (ASDs) have demonstrated that when crystallization is slow, these systems undergo liquid-liquid phase separation (LLPS) when the concentration of the drug in the medium exceeds its amorphous solubility. Following LLPS, a metastable equilibrium is formed where the concentration of drug in the continuous phase corresponds to the amorphous solubility while the dispersed phase is composed of a nanosized drug-rich phase. It has been reasoned that the drug-rich phase may act as a reservoir, enabling the rate of passive transport of the drug across a membrane to be maintained at the maximum value for an extended period of time. Herein, using clotrimazole as a model drug, and a flow-through diffusion cell, the reservoir effect is demonstrated. Supersaturated clotrimazole solutions at concentrations below the amorphous solubility show a linear relationship between the maximum flux and the initial concentration. Once the concentration exceeds the amorphous solubility, the maximum flux achieved reaches a plateau. However, the duration for which the high flux persists was found to be highly dependent on the number of drug-rich nanodroplets present in the donor compartment. Macroscopic amorphous particles of clotrimazole did not lead to the same reservoir effect observed with the nanodroplets formed through the process of LLPS. A first-principles mathematical model was developed which was able to fit the experimental receiver concentration-time profiles for concentration regimes both below and above amorphous solubility, providing support for the contention that the nanodroplet phase does not directly diffuse across the membrane but, instead, rapidly replenishes the drug in the aqueous phase that has been removed by transport across the membrane. This study provides important insight into the properties of

  17. Study on a novel flat renewal supported liquid membrane with D2EHPA and hydrogen nitrate for neodymium extraction

    Institute of Scientific and Technical Information of China (English)

    PEI Liang; WANG Liming; YU Guoqiang

    2012-01-01

    The Nd(Ⅲ) extraction in flat renewal supported liquid membrane (FRSLM),with polyvinylidene fluoride membrane and renewal solution including HNO3 solution as the stripping solution and di(2-ethylhexyl) phosphoric acid (D2EHPA) dissolved in kerosene as the membrane solution,was investigated.The effects of pH in the feed phase,volume ratio of membrane solution to stripping solution,concentration of HNO3 solution and concentration of carrier in the renewal phase on extraction of Nd(Ⅲ) were also studied,respectively.As a result,the optimum extraction conditions of Nd(Ⅲ) were obtained when concentration of HNO3 solution was 4.00 mol/L,concentration of D2EHPA was 0.100 mol/L,and volume ratio of membrane solution to stripping solution was 1.00 in the renewal phase,and pH was 4.60 in the feed phase.When initial concentration of Nd(Ⅲ) was 2.00× 10-4 mol/L,the extraction percentage of Nd(Ⅲ) was up to 92.9% in 75 min.

  18. Gas/liquid membrane contactors based on disubstituted polyacetylene for CO2 absorption liquid regeneration at high pressure and temperature

    NARCIS (Netherlands)

    Trusov, A.; Legkov, S.; Broeke, L.J.P. van den; Goetheer, E.L.V.; Khotimsky, V.; Volkov, A.

    2011-01-01

    This work deals with the study of chemical stability and the general behavior of hydrophobic glassy polymers with an excess of free volume fraction, such as poly[1-(trimethylsylil)-1-propyne] (PTMSP), poly[1-(trimethylgermil)-1-propyne] (PTMGP) and poly[4-methyl-2-pentyne] (PMP). The dense membranes

  19. Tb(Ⅲ) Transport in Dispersion Supported Liquid Membran System with D2EHPA as Carrier in Kerosene

    Institute of Scientific and Technical Information of China (English)

    PEI Liang; YAO Bing-hua; WANG Li-ming; MA Zhan-ying

    2011-01-01

    The transport of Tb(Ⅲ) in dispersion supported liquid membrane(DSLM) with polyvinylidene fluoride membrane(PVDF) as the support and dispersion solution including HCl solution as the stripping solution and di(2-ethylhexyl) phosphoric acid(D2EHPA) dissolved in kerosene as the membrane solution, has been studied. The effects of pH value, initial concentration of Tb(Ⅲ) and different ionic strength in the feed phase, volume ratio of membrane solution to stripping solution, concentration of HCl solution, concentration of carrier, different stripping agents in the dispersion phase on the transport of Tb(Ⅲ) have also been investigated, respectively. As a result, the optimum transport conditions of Tb(Ⅲ) were obtained, i.e., the concentration of HCl solution was 4.0 mol/L, the concentration of D2EHPA was 0.16 mol/L, the volume ratio of membrane solution to stripping solution was 30:30 in the dispersion phase and pH value was 4.5 in the feed phase. Ionic strength had no obvious effect on the transport of Tb(Ⅲ). Under the optimum conditions, the transport percentage of Tb(Ⅲ) was up to 96.1% in a transport time of 35 min when the initial concentration of Tb(Ⅲ) was 1.0× 10-4 mol/L. The diffusion coefficient of Tb(Ⅲ) in the membrane and the thickness of diffusion layer between feed phase and membrane phase were obtained and the values were 1.82× 10 -8 m2/s and 5.61 μm, respectively. The calculated results were in good agreement with the literature data.

  20. Separation of CO2 with Supported Ionic Liquid Membrane%离子液体支撑液膜分离CO_2

    Institute of Scientific and Technical Information of China (English)

    段永超; 伍艳辉; 于世昆; 李佟茗

    2012-01-01

    Supported liquid membrane (SLM applications in many fields such as hydrometallurgy, ) is a kind of important membrane technique which has biotechnology, gas separation, etc. A thorough summary of recent developments of supported liquid membranes used in the field of CO2 separation is provided. In this paper, two kinds of supported liquid membranes with different membrane phases, conventional carriers supported liquid membranes and supported ionic liquid membranes (SILMs), are introduced respectively. And the limits of conventional carriers supported liquid membrane are pointed out. The transport mechanism of gas in the SILMs is analyzed firstly. Then the progress of different SILMs are discussed intensively. For conventional ionic liquid membranes, the discussions focus on how the structure and content of ionic liquid as well as the support material influence the membrane performance. For task-specific ionic liquid membrane, different methods of functionalization and the CO2 permeability, selectivity and the liquid membrane stability of the corresponding supported task specific ionic liquid membranes are analyzed. Two kinds of new modification methods for supported ionic liquid membrane, poly (ionic liquid) membrane and supported gelled ionic liquid membrane, are also introduced. On this basis, the possible prospects of supported ionic liquid in the future are given.%支撑液膜是一种在湿法冶金、生物技术以及气体分离等多个领域都有应用的重要膜分离技术。本文回顾了支撑液膜技术分离CO2的研究进展,按照液膜相的不同,分类介绍了常规载体支撑液膜和离子液体支撑液膜,指出了常规载体支撑液膜分离CO2的局限性,重点介绍了离子液体支撑液膜分离CO2的发展,分析了气体在离子液体支撑液膜中的传质机理以及常规离子液体结构、含量和支撑膜材料等对分离效果的影响;讨论了离子液体的功能化方法以及功能化离

  1. Development and validation of a simple stability-indicating high performance liquid chromatographic method for the determination of miconazole nitrate in bulk and cream formulations.

    Science.gov (United States)

    De Zan, María M; Cámara, María S; Robles, Juan C; Kergaravat, Silvina V; Goicoechea, Héctor C

    2009-08-15

    A simple and stability-indicating high performance liquid chromatographic method was developed and validated for the determination of miconazole nitrate in bulk and cream preparations. The extraction step for cream samples consisted in a warming, cooling and centrifugation procedure that assures the elimination of the lipophilic matrix component, in order to avoid further precipitation in the chromatographic system. Separation was achieved on a ZORBAX Eclipse XDB - C18 (4.6 mm x 150 mm, 5 microm particle size) column, using a mobile phase consisting of water, methanol and acetonitrile, in a flow and solvent gradient elution for 15 min. The column was maintained at 25 degrees C and 10 microL of solutions were injected. UV detection was performed at 232 nm, although employment of a diode array detector allowed selectivity confirmation by peak purity evaluation. The method was validated reaching satisfactory results for selectivity, precision and accuracy. Degradation products in naturally aged samples could be simultaneously evaluated, without interferences in the quantitative analysis.

  2. Development and validation of a liquid chromatographic method for the simultaneous determination of aniracetam and its related substances in the bulk drug and a tablet formulation.

    Science.gov (United States)

    Papandreou, Georgios; Zorpas, Kostas; Archontaki, Helen

    2011-11-01

    Simultaneous determination of aniracetam and its related impurities (2-pyrrolidinone, p-anisic acid, 4-p-anisamidobutyric acid and (p-anisoyl)-4-methyl-2-pyrrolidinone) was accomplished in the bulk drug and in a tablet formulation using a high performance liquid chromatographic method with UV detection. Separation was achieved on a Hypersil BDS-CN column (150 mm × 4.0 mm, 5 μm) using a gradient elution program with solvent A composed of phosphate buffer (pH 4.0; 0.010 M) and solvent B of acetonitrile-phosphate buffer (pH 4.0; 0.010 M) (90:10, v/v). The flow rate of the mobile phase was 1.0 mL min(-1) and the total elution time, including the column re-equilibration, was approximately 20 min. The UV detection wavelength was varied appropriately among 210, 250 and 280 nm. Injection volume was 20 μL and experiments were conducted at ambient temperature. The developed method was validated in terms of system suitability, selectivity, linearity, range, precision, accuracy, limits of detection and quantification for the impurities, short term and long term stability of the analytes in the prepared solutions and robustness, following the ICH guidelines. Therefore, the proposed method was suitable for the simultaneous determination of aniracetam and its studied related impurities.

  3. Grafting of cellulose acetate with ionic liquids for biofuel purification by a membrane process: Influence of the cation.

    Science.gov (United States)

    Hassan Hassan Abdellatif, Faten; Babin, Jérôme; Arnal-Herault, Carole; David, Laurent; Jonquieres, Anne

    2016-08-20

    A new strategy was developed for grafting ionic liquids (ILs) onto cellulose acetate in order to avoid IL extraction and improve its performance for ethyl tert-butyl ether (ETBE) biofuel purification by the pervaporation membrane process. This work extended the scope of IL-containing membranes to the challenging separation of organic liquid mixtures, in which these ILs were soluble. The ILs contained the same bromide anion and different cations with increasing polar feature. The membrane properties were strongly improved by IL grafting. Their analysis in terms of structure-property relationships revealed the influence of the IL content, chemical structure and chemical physical parameters α, β, π* in the Kamlet-Taft polarity scale. The ammonium IL led to the best normalized flux of 0.182kg/m(2)h for a reference thickness of 5μm, a permeate ethanol content of 100% and an outstanding infinite separation factor for the azeotropic mixture EtOH/ETBE at 50°C.

  4. Effect of magnetized extender on sperm membrane integrity and development of oocytes in vitro fertilized with liquid storage boar semen.

    Science.gov (United States)

    Lee, Sang-Hee; Park, Choon-Keun

    2015-03-01

    The objective of this study was to evaluate the effect of a magnetized extender on sperm membrane damage and development of oocytes in vitro fertilized with liquid storage boar semen. Before semen dilution, extender was flowed through a neodymium magnet (0, 2000, 4000 and 6000G) for 5min and collected semen was preserved for 168h at 18°C. In results, plasma membrane integrity with live sperm was significantly higher in semen treated with extenders magnetized at 4000G than sperm treated with extenders magnetized at 0G during semen preservation for 120-168h (psperm was significantly lower in semen treated with extenders magnetized at 2000G than other groups during semen preservation for 168h. The ability of semen to achieve successful in vitro fertilization was also not significantly different among the groups during preservation. However, when the semen was preserved for 168h, the blastocyst formation rates were significantly higher at 6000G compared to 0 and 2000G (psperm membrane from damage, and improve the ability of rates of in vitro blastocyst development and magnetized semen diluter is beneficial for long liquid preservation of boar semen.

  5. Fibrous Support Stabilizes Nitrification Performance of a Membrane-Aerated Biofilm: The Effect of Liquid Flow Perturbation

    DEFF Research Database (Denmark)

    Terada, Akihiko; Ito, J; Matsumoto, S

    2009-01-01

    Nitrification stability and biofilm robustness were examined by comparing a fibrous support membrane-aerated biofilm reactor (FS-MABR), where a woven fibrous support was surrounded on a silicone tube, with an MABR. The overall mass transfer coefficient of oxygen for the FS-MABR, assuming no bound......Nitrification stability and biofilm robustness were examined by comparing a fibrous support membrane-aerated biofilm reactor (FS-MABR), where a woven fibrous support was surrounded on a silicone tube, with an MABR. The overall mass transfer coefficient of oxygen for the FS-MABR, assuming...... liquid flow rate condition was 49% and 75% in the FS-MABR and MABR, exhibiting robust biofilms grown on the fibrous support. The FS-MABR provided more stable nitrification performance than the MABR irrespective of a high liquid flow rate. Both reactors have deteriorated ammonium (NH4+-N) removal without...... a high liquid flow rate condition to eliminate excessive biomass, indicating that regular maintenance is essential to eliminate excessive biofilm from a MABR for nitrification, which potentially acts as a NH4+ diffusion barrier....

  6. Simulation studies of the membrane exchange assembly of an all-liquid, proton exchange membrane fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Byrd, Ethan D. [Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Everitt Laboratory, MC-702, 1406 W. Green St., Urbana, IL 61801-2918 (United States); Miley, George H. [Department of Nuclear, Plasma, and Radiological Engineering, University of Illinois at Urbana-Champaign, 100C NEL, 103 S. Goodwin Ave., Urbana, IL 61801 (United States)

    2008-01-21

    A model has been designed and constructed for the all-liquid, sodium borohydride/hydrogen peroxide fuel cell under development at the University of Illinois at Urbana-Champaign. The electrochemical behavior, momentum balance, and mass balance effects within the fuel cell are modeled using the Butler-Volmer equations, Darcy's law, and Fick's law, respectively, within a finite element modeling platform. The simulations performed with the model indicate that an optimal physical design of the fuel cell's flow channel land area or current collector exists when considering the pressure differential between channels, and the diffusion layer permeability and conductivity. If properties of the diffusion layer are known, the model is an effective method of improving the fuel cell design in order to achieve higher power density. (author)

  7. A strategy for the systematic development of a liquid chromatographic mass spectrometric screening method for polymer electrolyte membrane degradation products using isocratic and gradient phase optimized liquid chromatography.

    Science.gov (United States)

    Zedda, M; Tuerk, J; Teutenberg, T; Peil, S; Schmidt, T C

    2009-12-18

    Within the scope of research for target and non-target LC-MS/MS analysis of membrane degradation products of polymer electrolyte membrane fuel cells, a systematic method development for the separation of structurally similar compounds was performed by phase optimized liquid chromatography. Five different stationary phases with different selectivities were used. Isocratic separation for 4-hydroxybenzoic acid, isophthalic acid, terephthalic acid, 4-hydroxybenzaldehyde and 4-formylbenzoic acid was achieved on a C18 and a Phenyl phase. Using the PRISMA model the separation efficiency was optimized. This was achieved on a serially connected mixed stationary phase composed of 30 mm C18, 150 mm Phenyl and 60 mm C30. For the LC-MS screening of unknown degradation products from polymer electrolyte membranes in the product water of a fuel cell, a solvent gradient is mandatory for less polar or later eluting compounds. By means of 4-mercaptobenzoic acid it could be shown that a solvent gradient can be applied in order to elute later eluting compounds in a short time. The adaptability of this method for the qualitative analysis by target and non-target LC-MS/MS screening has been shown by means of 4-hydroxybenzoic acid. The combination of solvent gradient and isocratic conditions makes this approach attractive for the purpose of a screening method for known and unknown analytes in a water sample.

  8. Structure-Antibacterial Activity Relationships of Imidazolium-Type Ionic Liquid Monomers, Poly(ionic liquids) and Poly(ionic liquid) Membranes: Effect of Alkyl Chain Length and Cations.

    Science.gov (United States)

    Zheng, Zhiqiang; Xu, Qiming; Guo, Jiangna; Qin, Jing; Mao, Hailei; Wang, Bin; Yan, Feng

    2016-05-25

    The structure-antibacterial activity relationship between the small molecular compounds and polymers are still elusive. Here, imidazolium-type ionic liquid (IL) monomers and their corresponding poly(ionic liquids) (PILs) and poly(ionic liquid) membranes were synthesized. The effect of chemical structure, including carbon chain length of substitution at the N3 position and charge density of cations (mono- or bis-imidazolium) on the antimicrobial activities against both Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) was investigated by determination of minimum inhibitory concentration (MIC). The antibacterial activities of both ILs and PILs were improved with the increase of the alkyl chain length and higher charge density (bis-cations) of imidazolium cations. Moreover, PILs exhibited lower MIC values relative to the IL monomers. However, the antibacterial activities of PIL membranes showed no correlation to those of their analogous small molecule IL monomers and PILs, which increased with the charge density (bis-cations) while decreasing with the increase of alkyl chain length. The results indicated that antibacterial property studies on small molecules and homopolymers may not provide a solid basis for evaluating that in corresponding polymer membranes.

  9. Stuides on a Pb2+-selective electrode with a macrocyclic liquid membrane. Potentiometric determination of Pb2+ ions

    Directory of Open Access Journals (Sweden)

    MARIAN ISVORANU

    2006-12-01

    Full Text Available This paper presents experimental and theoretical data regarding the design, characterization and analytical applications of a non-expensive, liquid-membrane ion-selective electrode for Pb2+ ions. The membrane is a solution of the active complex formed by Pb2+ ions with dibenzo-18-crown-6-ionophore (DB-[18]-C-6 extracted in propylene carbonate (PC. The sucessful application of the developed electrode for the determination of Pb2+ ions in aqueos solution samples by direct potentiometry and potentiometric titration is presented. For the presented analytical results, there are insignificant systematic errors between the direct potentiometric method with the developed ion-selective electrode and atomic absorption spectrometry.

  10. Investigation of Ion Channel Activities of Gramicidin A in the Presence of Ionic Liquids Using Model Cell Membranes.

    Science.gov (United States)

    Ryu, Hyunil; Lee, Hwankyu; Iwata, Seigo; Choi, Sangbaek; Kim, Moon Ki; Kim, Young-Rok; Maruta, Shinsaku; Kim, Sun Min; Jeon, Tae-Joon

    2015-07-20

    Ionic liquids (ILs) are considered to be green solvents because of their non-volatility. Although ILs are relatively safe in the atmospheric environment, they may be toxic in other environments. Our previous research showed that the cytotoxicity of ILs to biological organisms is attributable to interference with cell membranes by IL insertion. However, the effects of ILs on ion channels, which play important roles in cell homeostasis, have not been comprehensively studied to date. In this work, we studied the interactions between ILs and lipid bilayer membranes with gramicidin A ion channels. We used two methods, namely electrical and fluorescence measurements of ions that permeate the membrane. The lifetimes of channels were increased by all the ILs tested in this work via stabilizing the compressed structure of the lipid bilayer and the rate of ion flux through gA channels was decreased by changing the membrane surface charge. The former effect, which increased the rate of ion flux, was dominant at high salt concentrations, whereas the latter, which decreased the rate of ion flux, was dominant at low salt concentrations. The effects of ILs increased with increasing concentration and alkyl chain length. The experimental results were further studied using molecular dynamics simulations.

  11. Reforming of Liquid Hydrocarbons in a Novel Hydrogen-Selective Membrane-Based Fuel Processor

    Energy Technology Data Exchange (ETDEWEB)

    Shamsuddin Ilias

    2006-03-10

    In this work, asymmetric dense Pd/porous stainless steel composite membranes were fabricated by depositing palladium on the outer surface of the tubular support. The electroless plating method combined with an osmotic pressure field was used to deposit the palladium film. Surface morphology and microstructure of the composite membranes were characterized by SEM and EDX. The SEM and EDX analyses revealed strong adhesion of the plated pure palladium film on the substrate and dense coalescence of the Pd film. Membranes were further characterized by conducting permeability experiments with pure hydrogen, nitrogen, and helium gases at temperatures from 325 to 450 C and transmembrane pressure differences from 5 to 45 psi. The permeation results showed that the fabricated membranes have both high hydrogen permeability and selectivity. For example, the hydrogen permeability for a composite membrane with a 20 {micro}m Pd film was 3.02 x 10{sup -5} moles/m{sup 2}.s.Pa{sup 0.765} at 450 C. Hydrogen/nitrogen selectivity for this composite membrane was 1000 at 450 C with a transmembrane pressure difference of 14.7 psi. Steam reforming of methane is one of the most important chemical processes in hydrogen and syngas production. To investigate the usefulness of palladium-based composite membranes in membrane-reactor configuration for simultaneous production and separation of hydrogen, steam reforming of methane by equilibrium shift was studied. The steam reforming of methane using a packed-bed inert membrane tubular reactor (PBIMTR) was simulated. A two-dimensional pseudo-homogeneous reactor model with parallel flow configuration was developed for steam reforming of methane. The shell volume was taken as the feed and sweep gas was fed to the inside of the membrane tube. Radial diffusion was taken into account for concentration gradient in the radial direction due to hydrogen permeation through the membrane. With appropriate reaction rate expressions, a set of partial differential

  12. Electromembrane extraction of polar basic drugs from plasma with pure bis(2-ethylhexyl) phosphite as supported liquid membrane

    DEFF Research Database (Denmark)

    Huang, Chuixiu; Seip, Knut Fredrik; Gjelstad, Astrid

    2016-01-01

    were analyzed by high-performance liquid chromatography-ultraviolet detection (HPLC-UV). In contrast to other SLMs reported for polar basic drugs in the literature, the SLM of DEHPi was highly stable in contact with plasma, and the system-current across the SLM was easily kept below 50 μA. Thus......Electromembrane extraction (EME) of polar basic drugs from human plasma was investigated for the first time using pure bis(2-ethylhexyl) phosphite (DEHPi) as the supported liquid membrane (SLM). The polar basic drugs metaraminol, benzamidine, sotalol, phenylpropanolamine, ephedrine......, and trimethoprim were selected as model analytes, and were extracted from 300 μL of human plasma, through 10 μL of DEHPi as SLM, and into 100 μL of 10 mM formic acid as acceptor solution. The extraction potential across the SLM was 100 V, and extractions were performed for 20 min. After EME, the acceptor solutions...

  13. Simulation studies of ammonia removal from water in a membrane contactor under liquid-liquid extraction mode.

    Science.gov (United States)

    Mandowara, Amish; Bhattacharya, Prashant K

    2011-01-01

    Simulation studies were carried out, in an unsteady state, for the removal of ammonia from water via a membrane contactor. The contactor had an aqueous solution of NH(3) in the lumen and sulphuric acid in the shell side. The model equations were developed considering radial and axial diffusion and convection in the lumen. The partial differential equations were converted by the finite difference technique into a series of stiff ordinary differential equations w.r.t. time and solved using MATLAB. Excellent agreement was observed between the simulation results and experimental data (from the literature) for a contactor of 75 fibres. Excellent agreement was also observed between the simulation results and laboratory-generated data from a contactor containing 10,200 fibres. Our model is more suitable than the plug-flow model for designing the operation of the membrane contactor. The plug-flow model over-predicts the fractional removal of ammonia and was observed to be limited when designing longer contactors.

  14. Fabrication of highly co2 selective metal organic framework membrane using liquid phase epitaxy approach

    KAUST Repository

    Eddaoudi, Mohamed

    2016-01-28

    Embodiments include a method of making a metal organic framework membrane comprising contacting a substrate with a solution including a metal ion and contacting the substrate with a solution including an organic ligand, sufficient to form one or more layers of a metal organic framework on a substrate. Embodiments further include a defect-free metal organic framework membrane comprising MSiF6(pyz)2, wherein M is a metal, wherein the thickness of the membrane is less than 1,000 µm, and wherein the metal organic has a growth orientation along the [110] plane relative to a substrate.

  15. Interaction of the organic tin chloride with the liquid model membranes

    Energy Technology Data Exchange (ETDEWEB)

    Podolak, M; Engel, G; Man, D [Institute of Physics, Opole University, Oleska 48, 45-052 Opole (Poland)

    2007-08-15

    The objective of the work was to investigate the effect of organic tin chloride (C{sub 3}H{sub 7}){sub 3}SnCl on the electric parameters of membranes in the form of filters of the company Synpor (Czech Republic) impregnated with various fatty acids, dissolved with carbon tetrachloride (CCl{sub 4}). Three carboxylic acids were used in the study: palmitic, arachidic and oleic, and dissolvent of the acids (CCl{sub 4}) as well as butylene ester of lauric acid. In all cases, introduction of tin chloride of constant concentration amounting to 0.15 mM to the measurement chamber resulted in induction of membrane voltage. In case of pure lauric acid and CCl{sub 4}, the voltage reached the maximum value and then decreased to a certain constant value. In the case of all acids dissolved in CCl{sub 4}, the voltage increased only up to a certain constant value. Voltage drop (below the value) was observed after application of appropriately high concentration of tin chloride, in case of membranes impregnated with the mixture of lauric acid ester with CCl{sub 4} and palmitic acid with CCl{sub 4}. The study also demonstrated that electrical resistance of membranes impregnated with carboxylic acid increased in the presence of tin chloride and decreased in case of membranes impregnated with lauric acid ester. However, electric capacities of membranes did not significant change.

  16. Interaction of the organic tin chloride with the liquid model membranes

    Science.gov (United States)

    Podolak, M.; Engel, G.; Man, D.

    2007-08-01

    The objective of the work was to investigate the effect of organic tin chloride (C3H7)3SnCl on the electric parameters of membranes in the form of filters of the company Synpor (Czech Republic) impregnated with various fatty acids, dissolved with carbon tetrachloride (CCl4). Three carboxylic acids were used in the study: palmitic, arachidic and oleic, and dissolvent of the acids (CCl4) as well as butylene ester of lauric acid. In all cases, introduction of tin chloride of constant concentration amounting to 0.15 mM to the measurement chamber resulted in induction of membrane voltage. In case of pure lauric acid and CCl4, the voltage reached the maximum value and then decreased to a certain constant value. In the case of all acids dissolved in CCl4, the voltage increased only up to a certain constant value. Voltage drop (below the value) was observed after application of appropriately high concentration of tin chloride, in case of membranes impregnated with the mixture of lauric acid ester with CCl4 and palmitic acid with CCl4. The study also demonstrated that electrical resistance of membranes impregnated with carboxylic acid increased in the presence of tin chloride and decreased in case of membranes impregnated with lauric acid ester. However, electric capacities of membranes did not significant change.

  17. Characterization of carbon dioxide transfer in a hollow fiber membrane module as a solution for gas-liquid transfer in microgravity conditions.

    Science.gov (United States)

    Farges, Berangere; Duchez, David; Dussap, Claude-Gilles; Cornet, Jean-F.

    In microgravity, one of the major difficulties encountered in closed photosynthetic reactors is the gas-liquid transfer with the necessity to provide CO2 (carbon source, pH control) and to recover the produced O2 . Indeed, reduced gravity is expected to modify gas liquid transfer and liquid phase mixing characteristics inside photobioreactors conceived to regenerate atmosphere of closed life-support systems. To obtain efficient mass transfer conditions and mixing of phases, several solutions are possible: use of rotating reactor (centrifugal field), use of forced, co-current convective reactor with gas-liquid separator and use of membrane modules. In terms of space process engineering, the membrane reactor can be a valuable alternative in which the gas and liquid phases are separated with a selectively permeable membrane. The rate-limiting factors in this reactor were demonstrated to be the surface of membrane A needed for diffusion of gases and the CO2 and O2 mass transfer coefficients in the liquid phase kL. How-ever, the major advantages of the membrane reactor are that it is composed of a hydrophobic membrane (here PTFE) which showed a high hydrophobicity, an important chemical resis-tance, a very long term stability and overall which is favourable to gas transfer. Moreover, the volumetric mass transfer coefficients are sufficiently high to build compact systems with small footprints, no complex rotating devices and lighter weights. This paper describes first the development of a system enabling the accurate characterization of the mass transfer limiting step for a PTFE membrane module. This original technical apparatus, together with a technical assessment of membrane permeability to different gases, is associated with a balance model, determining thus completely the CO2 mass transfer problem between phases. First results are given and discussed for the CO2 mass transfer coefficient CO kL 2 obtained in case of an absorption experiment at pH = 8 using the

  18. 离子液体二氧化碳分离膜研究进展%Developments in ionic liquid membranes for CO2 separation

    Institute of Scientific and Technical Information of China (English)

    赵薇; 贺高红; 刘红晶; 李凤华; 张莹

    2014-01-01

    Supported ionic liquid membrane (SILM) has relatively low stability at high cross-membrane pressure difference (0.25-0.3MPa). Polymerized ionic liquid membrane and ionic liquid − polymer mixed membrane can eliminate the instability problem of the SILM. This review presented a summary on the latest developments in the research of SILM,polymerized ionic liquid membrane and ionic liquid − polymer mixed membrane used for CO2 separation with respect to the separation performance,transport mechanism and stability. The research on a three-component mixed-matrix membrane,inorganic particle−ionic liquid−polymer mixed membrane,by dispersing inorganic nano-particles in polymer matrix containing ionic liquid was also introduced. It was indicated that the challenges for the ionic liquid membranes technologies applied on an industrial scale include the trade-off between high CO2 permeation rate and high stability,and the difficulties with the structural arrangement of the mixed membrane. Significant improvements of the separation performance and stability of the ionic liquid membranes can be achieved by developing new membrane materials,improving membrane fabrication techniques to reduce membrane thickness and optimize membrane structure. Inorganic particle − ionic liquid − polymer mixed membrane showed a good prospect in CO2 separation for its higher separation performance combining with better stability. The study on the fabrication,structure,separation performance and mechanism of the new type of membrane will inevitably draw considerable attention.%离子液体支撑液膜在较大跨膜压差(0.25~0.3MPa)下的稳定性较差,具有较好稳定性的聚离子液体膜和离子液体-聚合物共混膜等逐渐被关注。本文综述了离子液体支撑液膜、聚离子液体膜、离子液体−聚合物共混膜等离子液体膜CO2分离性能、分离机理及稳定性的最新研究进展,介绍了无机颗粒-离子液体-聚合物共混膜的

  19. Simulation of cesium nitrate extraction by a calixarene. Application to supported liquid membranes transport; Modelisation de l`extraction du nitrate de cesium par un calixarene. Application a la modelisation du transport a travers des membranes liquides supportees

    Energy Technology Data Exchange (ETDEWEB)

    Sorel, C.

    1996-12-12

    This work fits into the general pattern of the CEA studies on the decontamination of liquid effluents containing long-lived radioactive isotopes. Some calixarenes have proved to be very effective to selectively extract the cesium of aqueous solutions whose composition simulates those of the effluents to be reprocessed. On account of the difficulty of the studied extraction mechanisms, a physical and chemical simulation has been necessary. The system takes into account: 1)a concentrated nitric acid aqueous phase and/or sodium nitrate 2)an organic phase constituted by the diluent 1,2-nitro-phenyl-octyl-ether and 1,3-diisopropoxy-calix(4)arene-couronne-6. The use of concentrated aqueous solutions requires to take into account variations to ideality by the mean of activity coefficients reckoning. The different theories on the reckoning of variations to ideality in aqueous or organic phases are described in the first part. The determination of cesium and sodium nitrates activity coefficients in very concentrated matrices has required an important theoretical and experimental study which is given in the second part. The aim of this study was indeed to complete the thermodynamic data of cesium and sodium nitrates aqueous solutions. The computerized tools required for the modeling are reviewed. The stoichiometry of the extracted species in the organic phase has been determined in the third part. The supported membrane technique is an original method of separation by liquid-liquid extraction. A membrane transport model has been developed and is given in the last part of this work. (O.M.). 128 refs.

  20. Improving the Conductivity of Sulfonated Polyimides as Proton Exchange Membranes by Doping of a Protic Ionic Liquid

    Directory of Open Access Journals (Sweden)

    Bor-Kuan Chen

    2014-10-01

    Full Text Available Proton exchange membranes (PEMs are a key component of a proton exchange membrane fuel cell. Sulfonated polyimides (SPIs were doped by protic ionic liquid (PIL to prepare composite PEMs with substantially improved conductivity. SPIs were synthesized from diamine, 2,2-bis[4-(4-amino-phenoxyphenyl]propane (BAPP, sulfonated diamine, 4,4'-diamino diphenyl ether-2,2'-disulfonic acid (ODADS and aromatic anhydride. BAPP improved the mechanical and thermal properties of SPIs, while ODADS enhanced conductivity. A PIL, 1-vinylimidazolium trifluoromethane-sulfonate ([VIm][OTf], was utilized. [VIm][OTf] offered better conductivity, which can be attributed to its vinyl chemical structure attached to an imidazolium ring that contributed to ionomer-PIL interactions. We prepared sulfonated polyimide/ionic liquid (SPI/IL composite PEMs using 50 wt% [VIm][OTf] with a conductivity of 7.17 mS/cm at 100 °C, and in an anhydrous condition, 3,3',4,4'-diphenyl sulfone tetracarboxylic dianhydride (DSDA was used in the synthesis of SPIs, leading to several hundred-times improvement in conductivity compared to pristine SPIs.

  1. [Impacts of filamentous bulking on treatment effect and fouling characteristics of nonwoven bioreactor].

    Science.gov (United States)

    Shi, Kuan; Xue, Gang; Gao, Pin; Wu, Fan

    2014-06-01

    Sludge flocs morphology and effluent qualities of nonwoven bioreactor during filamentous bulking and normal sludge status were compared. Flux variations, analysis of filtration resistances and extracellular polymer substances (EPS) contents during filamentous bulking and normal sludge status were studied. The results showed that the average particle size of bulking sludge flocs and normal sludge flocs was 448.6 microm and 234.8 microm, respectively. During the bulking sludge status, the average COD and NH4(+) -N removal rate and effluent turbidity were 90.1%, 93.1% and 1.33 NTU, respectively, compared with 91.4% , 97.0% and 0.99 NTU during the normal sludge status. Filamentous bulking had little impact on COD removal, while it inhibited NH4(+) -N removal to a certain extent and had slight impact on effluent turbidity. Average membrane flux decay rates during the bulking sludge status and the normal sludge status were 3.29 L x (m2 x h2)(-1) and 4.87 L x (m2 x h2)(-1), respectively, and the fouling during bulking sludge status was slighter. Reversible fouling was the main fouling when sludge was bulking while irreversible fouling was the main fouling when the sludge was in normal status. The prior occurrence of reversible fouling could reduce irreversible fouling therefore slow down the flux decline. Soluble microbial products (SMP) contents in normal sludge mixed liquid and bulking sludge mixed liquid were 21.369 mg x L(-1) and 10.182 mg x L(-1), respectively, protein/polysaccharide (P/C) was 0.370 and 0.497, respectively, SMP gross was related to fouling resistance and P/C was associated with reversible fouling proportion. The relation between loosely bound EPS in mixed liquid sludge and membrane fouling was similar to SMP. Sludge with more EPS could accumulate on membrane more easily, and the EPS that accumulated on membrane was mainly protein. EPS gross in mixed liquid sludge, EPS in membrane surface sludge and their P/C all had positive correlations to

  2. Ionic liquids effects on the permeability of photosynthetic membranes probed by the electrochromic shift of endogenous carotenoids.

    Science.gov (United States)

    Malferrari, Marco; Malferrari, Danilo; Francia, Francesco; Galletti, Paola; Tagliavini, Emilio; Venturoli, Giovanni

    2015-11-01

    Ionic liquids (ILs) are promising materials exploited as solvents and media in many innovative applications, some already used at the industrial scale. The chemical structure and physicochemical properties of ILs can differ significantly according to the specific applications for which they have been synthesized. As a consequence, their interaction with biological entities and toxicity can vary substantially. To select highly effective and minimally harmful ILs, these properties need to be investigated. Here we use the so called chromatophores--protein-phospholipid membrane vesicles obtained from the photosynthetic bacterium Rhodobacter sphaeroides--to assess the effects of imidazolinium and pyrrolidinium ILs, with chloride or dicyanamide as counter anions, on the ionic permeability of a native biological membrane. The extent and modalities by which these ILs affect the ionic conductivity can be studied in chromatophores by analyzing the electrochromic response of endogenous carotenoids, acting as an intramembrane voltmeter at the molecular level. We show that chromatophores represent an in vitro experimental model suitable to probe permeability changes induced in cell membranes by ILs differing in chemical nature, degree of oxygenation of the cationic moiety and counter anion.

  3. Stripping dispersion hollow fiber liquid membrane containing carrier PC-88A and HNO3 for the extraction of Sm3+

    Institute of Scientific and Technical Information of China (English)

    Liang Pei; Li Ming Wang; Wei Guo

    2012-01-01

    Stripping dispersion hollow fiber liquid membrane system (SDHFLM) containing feed phase adding acetate buffer solution and dispersion solution with HNO3 solution as the stripping solution and membrane solution of 2-ethyl hexyl phosphoric acid-mono-2-ethylhexyl ester (PC-88A) dissolved in kerosene,has been studied for the extraction of Sm3+.Many factors including pH value,volume ratio of membrane solution to stripping solution (O/W) and carrier concentration on Sm3+ extraction were investigated.Experimental results indicate that the optimum extraction conditions of Sm3+ were obtained as that PC-88A concentration was 0.120 mol/L,and O/W was 1.00 in the dispersion phase,and pH value was 4.80 in the feed phase.When initial Sm3+ concentration was 1.20 × 10-4 mol/L,the extraction percentage of Sm3+ was up to 92.8% in 160 min.

  4. Nanoscopic substructures of raft-mimetic liquid-ordered membrane domains revealed by high-speed single-particle tracking

    Science.gov (United States)

    Wu, Hsiao-Mei; Lin, Ying-Hsiu; Yen, Tzu-Chi; Hsieh, Chia-Lung

    2016-02-01

    Lipid rafts are membrane nanodomains that facilitate important cell functions. Despite recent advances in identifying the biological significance of rafts, nature and regulation mechanism of rafts are largely unknown due to the difficulty of resolving dynamic molecular interaction of rafts at the nanoscale. Here, we investigate organization and single-molecule dynamics of rafts by monitoring lateral diffusion of single molecules in raft-containing reconstituted membranes supported on mica substrates. Using high-speed interferometric scattering (iSCAT) optical microscopy and small gold nanoparticles as labels, motion of single lipids is recorded via single-particle tracking (SPT) with nanometer spatial precision and microsecond temporal resolution. Processes of single molecules partitioning into and escaping from the raft-mimetic liquid-ordered (Lo) domains are directly visualized in a continuous manner with unprecedented clarity. Importantly, we observe subdiffusion of saturated lipids in the Lo domain in microsecond timescale, indicating the nanoscopic heterogeneous molecular arrangement of the Lo domain. Further analysis of the diffusion trajectory shows the presence of nano-subdomains of the Lo phase, as small as 10 nm, which transiently trap the lipids. Our results provide the first experimental evidence of non-uniform molecular organization of the Lo phase, giving a new view of how rafts recruit and confine molecules in cell membranes.

  5. Nanoscopic substructures of raft-mimetic liquid-ordered membrane domains revealed by high-speed single-particle tracking.

    Science.gov (United States)

    Wu, Hsiao-Mei; Lin, Ying-Hsiu; Yen, Tzu-Chi; Hsieh, Chia-Lung

    2016-01-01

    Lipid rafts are membrane nanodomains that facilitate important cell functions. Despite recent advances in identifying the biological significance of rafts, nature and regulation mechanism of rafts are largely unknown due to the difficulty of resolving dynamic molecular interaction of rafts at the nanoscale. Here, we investigate organization and single-molecule dynamics of rafts by monitoring lateral diffusion of single molecules in raft-containing reconstituted membranes supported on mica substrates. Using high-speed interferometric scattering (iSCAT) optical microscopy and small gold nanoparticles as labels, motion of single lipids is recorded via single-particle tracking (SPT) with nanometer spatial precision and microsecond temporal resolution. Processes of single molecules partitioning into and escaping from the raft-mimetic liquid-ordered (Lo) domains are directly visualized in a continuous manner with unprecedented clarity. Importantly, we observe subdiffusion of saturated lipids in the Lo domain in microsecond timescale, indicating the nanoscopic heterogeneous molecular arrangement of the Lo domain. Further analysis of the diffusion trajectory shows the presence of nano-subdomains of the Lo phase, as small as 10 nm, which transiently trap the lipids. Our results provide the first experimental evidence of non-uniform molecular organization of the Lo phase, giving a new view of how rafts recruit and confine molecules in cell membranes.

  6. Observations on the use of membrane filtration and liquid impingement to collect airborne microorganisms in various atmospheric environments

    Science.gov (United States)

    Griffin, Dale W.; Gonzalez, C.; Teigell, N.; Petrosky, T.; Northup, D.E.; Lyles, M.

    2011-01-01

    The influence of sample-collection-time on the recovery of culturable airborne microorganisms using a low-flow-rate membrane-filtration unit and a high-flow-rate liquid impinger were investigated. Differences in recoveries were investigated in four different atmospheric environments, one mid-oceanic at an altitude of ~10.0 m, one on a mountain top at an altitude of ~3,000.0 m, one at ~1.0 m altitude in Tallahassee, Florida, and one at ~1.0 m above ground in a subterranean-cave. Regarding use of membrane filtration, a common trend was observed: the shorter the collection period, the higher the recovery of culturable bacteria and fungi. These data also demonstrated that lower culturable counts were common in the more remote mid-oceanic and mountain-top atmospheric environments with bacteria, fungi, and total numbers averaging (by sample time or method categories) filtration for aeromicrobiology studies if start-up costs are not an issue and temperature permits use; (2) although membrane filtration is more cost friendly and has a 'typically' wider operational range, its limits include loss of cell viability with increased sample time and issues with effectively extracting nucleic acids for community-based analyses; (3) the ability to recover culturable microorganisms is limited in 'extreme' atmospheric environments and thus the use of a 'limited' methodology in these environments must be taken into account; and (4) the atmosphere culls, i.e., everything is not everywhere. ?? 2010 US Government.

  7. Enzymatic membrane reactor for full saccharification of ionic liquid-pretreated microcrystalline cellulose.

    Science.gov (United States)

    Lozano, Pedro; Bernal, Berenice; Jara, Antonio G; Belleville, Marie-Pierre

    2014-01-01

    Ultrafiltration reactors based on polymeric or ceramic membranes were shown to be suitable catalytic systems for fast enzymatic saccharification of cellulose, allowing the full recovery and reuse of enzymes. By pre-treating cellulose with the IL 1-butyl-3-methylimidazolium chloride, the suitability of this substrate for enzymatic saccharification in a reactor based on polymeric ultrafiltration membranes was demonstrated, leading to 95% cellulose hydrolysis in 4h at 50°C. The filtration process gave a clear glucose solution (up to 113 mM) at constant permeate flow (24.7 L h(-1) m(-2)), allowing the enzyme to be reused for 9 operation cycles under semi-continuous operation, without any loss of enzyme activity. Under continuous operation mode and using ceramic ultrafiltration membranes at different residence times, the enzymatic reactor showed constant profiles in both the permeate flow rate and the glucose concentration, demonstrating the excellent suitability of the proposed approach for the saccharification of cellulose.

  8. Confinement of Ionic Liquids in Nanocages: Tailoring the Molecular Sieving Properties of ZIF-8 for Membrane-Based CO2 Capture.

    Science.gov (United States)

    Ban, Yujie; Li, Zhengjie; Li, Yanshuo; Peng, Yuan; Jin, Hua; Jiao, Wenmei; Guo, Ang; Wang, Po; Yang, Qingyuan; Zhong, Chongli; Yang, Weishen

    2015-12-14

    Fine-tuning of effective pore size of microporous materials is necessary to achieve precise molecular sieving properties. Herein, we demonstrate that room temperature ionic liquids can be used as cavity occupants for modification of the microenvironment of MOF nanocages. Targeting CO2 capture applications, we tailored the effective cage size of ZIF-8 to be between CO2 and N2 by confining an imidazolium-based ionic liquid [bmim][Tf2 N] into ZIF-8's SOD cages by in-situ ionothermal synthesis. Mixed matrix membranes derived from ionic liquid-modified ZIF-8 exhibited remarkable combinations of permeability and selectivity that transcend the upper bound of polymer membranes for CO2 /N2 and CO2 /CH4 separation. We observed an unusual response of the membranes to varying pressure, that is, an increase in the CO2 /CH4 separation factor with pressure, which is highly desirable for practical applications in natural gas upgrading.

  9. Highly selective separation of carbon dioxide from nitrogen and methane by nitrile/glycol-difunctionalized ionic liquids in supported ionic liquid membranes (SILMs).

    Science.gov (United States)

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

    2014-07-03

    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, the two classes of ILs benefit from the presence of a nitrile group in different ways. The difunctionalized pyrrolidinium ILs exhibit an increase in CO2 permeance, whereas the permeances of the contaminant gases rise negligibly, resulting in high gas separation selectivities. In the imidazolium ILs, the presence of a nitrile group does not always increase the CO2 permeance nor does it increase the CO2 solubility, as showed in situ by the ATR-FTIR spectroscopic method. High selectivity of these ILs is caused by the considerably reduced permeances of N2 and CH4, most likely due to the ability of the -CN group to reject the nonpolar contaminant gases. Apart from the CO2 solubility, IL-CO2 interactions and IL swelling were studied with the in situ ATR-FTIR spectroscopy. Different strengths of the IL-CO2 interactions were found to be the major difference between the two classes of ILs. The difunctionalized ILs interacted stronger with CO2 than the glycol-functionalized ILs, as manifested in the smaller bandwidths of the bending mode band of CO2 for the latter.

  10. Liquid Crystal Sulfonated Aramids as Proton Exchange Membranes for Fuel Cell Applications

    NARCIS (Netherlands)

    Gao, J.

    2015-01-01

    Two sulfonated aramids, poly(2,2’-disulfonylbenzidine terephthalamide) (PBDT) and poly(2,2’-disulfonylbenzidine isophthalamide) (PBDI) were synthesized with the aim to explore their unique morphology for proton exchange membrane applications. Due to the different polymer structures, PBDT forms a nem

  11. Purification of inkjet ink from water using liquid phase, electric discharge polymerization and cellulosic membrane filtration.

    Science.gov (United States)

    Jordan, Alexander T; Hsieh, Jeffery S; Lee, Daniel T

    2013-01-01

    A method to separate inkjet ink from water was developed using a liquid phase, electric discharge process. The liquid phase, electric discharge process with filtration or sedimentation was shown to remove 97% of inkjet ink from solutions containing between 0.1-0.8 g/L and was consistent over a range of treatment conditions. Additionally, particle size analysis of treated allyl alcohol and treated propanol confirmed the electric discharge treatment has a polymerization mechanism, and small molecule analysis of treated methanol using gas chromatography and mass spectroscopy confirmed the mechanism was free radical initiated polymerization.

  12. X-ray and Electrochemical Impedance Spectroscopy Diagnostic Investigations of Liquid Water in Polymer Electrolyte Membrane Fuel Cell Gas Diffusion Layers

    Science.gov (United States)

    Antonacci, Patrick

    In this thesis, electrochemical impedance spectroscopy (EIS) and synchrotron x-ray radiography were utilized to characterize the impact of liquid water distributions in polymer electrolyte membrane fuel cell (PEMFC) gas diffusion layers (GDLs) on fuel cell performance. These diagnostic techniques were used to quantify the effects of liquid water visualized on equivalent resistances measured through EIS. The effects of varying the thickness of the microporous layer (MPL) of GDLs were studied using these diagnostic techniques. In a first study on the feasibility of this methodology, two fuel cell cases with a 100 microm-thick and a 150 microm-thick MPL were compared under constant current density operation. In a second study with 10, 30, 50, and 100 microm-thick MPLs, the liquid water in the cathode substrate was demonstrated to affect mass transport resistance, while the liquid water content in the anode (from back diffusion) affected membrane hydration, evidenced through ohmic resistance measurements.

  13. Research Progress in Separation of CO2 by Supported Liquid Membrane With Ionic Liquid%离子液体支撑液膜分离CO2的研究进展

    Institute of Scientific and Technical Information of China (English)

    徐世博; 刘东斌; 申延明

    2013-01-01

    总结了离子液体支撑液膜分离CO2的研究进展,简要分析了气体在离子液体支撑液膜中的传质机理;介绍了离子液体支撑液膜的制备方法及影响离子液体支撑液膜稳定性的因素;指出了今后用于分离CO2的离子液体支撑液膜的发展方向。%The research progress in separation of CO2 by ionic liquid supported liquid membrane was summarized. The mass transfer mechanism of gas in the supported ionic liquid membrane was analyzed. Then the preparation method of supported ionic liquid membrane was introduced as well as the factors influencing its stability. Finally development direction of the supported ionic liquid membrane for separation of CO2 in the future was pointed out.

  14. Binding of β-Amyloid (1–42) Peptide to Negatively Charged Phospholipid Membranes in the Liquid-Ordered State: Modeling and Experimental Studies

    OpenAIRE

    Ahyayauch, Hasna; Raab, Michal; Busto, Jon V.; Andraka, Nagore; Arrondo, José-Luis R.; Masserini, Massimo; Tvaroska, Igor; Goñi, Félix M.

    2012-01-01

    To explore the initial stages of amyloid β peptide (Aβ42) deposition on membranes, we have studied the interaction of Aβ42 in the monomeric form with lipid monolayers and with bilayers in either the liquid-disordered or the liquid-ordered (Lo) state, containing negatively charged phospholipids. Molecular dynamics (MD) simulations of the system have been performed, as well as experimental measurements. For bilayers in the Lo state, in the absence of the negatively charged lipids, interaction i...

  15. Modeling the Liquid Water Transport in the Gas Diffusion Layer for Polymer Electrolyte Membrane Fuel Cells Using a Water Path Network

    OpenAIRE

    Dietmar Gerteisen; Robert Alink

    2013-01-01

    In order to model the liquid water transport in the porous materials used in polymer electrolyte membrane (PEM) fuel cells, the pore network models are often applied. The presented model is a novel approach to further develop these models towards a percolation model that is based on the fiber structure rather than the pore structure. The developed algorithm determines the stable liquid water paths in the gas diffusion layer (GDL) structure and the transitions from the paths to the subsequent ...

  16. Use of Ionic Liquid-filled Semipermeable Membrane for Extraction of Polycyclic Aromatic Hydrocarbons in Water

    Institute of Scientific and Technical Information of China (English)

    Wen Yan ZHAO; Meng HAN; Shu Gui DAI; Xia ZHONG

    2005-01-01

    A novel and facile sample preparation method was developed for the extraction of polycyclic aromatic hydrocarbons (PAHs) in aqueous sample solution using 1-butyl-3-methylimidazolium hexafluorophosphate ([C4MIM] [PF6]) - filled semipermeable membrane. For24 hrs extraction of naphthalene, 1-methylnaphthalene, 2-chloronaphthalene, phenanthrene, the result showed that the extraction efficiency, correlation coefficient (R2) and RSD (n=5) were in the range of 67-102 %, 0.9870-0.9962, and 2.1-5.3 %, respectively.

  17. Membrane distillation and reverse electrodialysis for near-zero liquid discharge and low energy seawater desalination

    OpenAIRE

    Tufa, R.; Curcio, E.; Brauns, E; van Baak, W.; Fontananova, E.; Di Profio, G.

    2015-01-01

    With a total capacity of 70 million cubic meters per day, seawater desalination industry represents the most affordable source of drinking water for many people living in arid areas of the world. Seawater Reverse Osmosis (SWRO) technology, driven by the impressive development in membrane materials, modules and process design, currently shows an overall energy consumption of 3-4 kWh per m(3) of desalted water, substantially lower than thermal systems; however, the theoretical energy demand to ...

  18. Performance analysis of a liquid desiccant and membrane contactor hybrid air-conditioning system

    Energy Technology Data Exchange (ETDEWEB)

    Bergero, Stefano; Chiari, Anna [DIPARC, Faculty of Architecture, University of Genoa, Stradone S. Agostino 37, 16123 Genova (Italy)

    2010-11-15

    The present study examines the performances of a hybrid air-conditioning system in which a vapour-compression inverse cycle is integrated with an air dehumidification system working with hygroscopic solution and hydrophobic membrane. This model may be a valid alternative to traditional summertime air-conditioning system, in which the air is cooled to below its dew-point temperature and subsequently reheated. The proposed hybrid system involves simultaneously cooling and dehumidifying the air conveyed to the conditioned ambient in an air-solution membrane contactor. An LiCl solution is cooled by means of a vapour-compression inverse cycle using the refrigerant KLEA 407C. The solution is regenerated in another membrane contactor by exploiting the heat rejected by the condenser. A SIMULINK calculation programme was designed in order to simulate the system under examination in steady-state conditions. The performances of the system were analysed on varying a few significant operating parameters, and were compared with those of a traditional direct-expansion air-conditioning plant in typical summertime conditions. The results of the simulations revealed significant energy savings, which, in particular operating conditions, may exceed 50%. (author)

  19. The Effect of Microporous Polymeric Support Modification on Surface and Gas Transport Properties of Supported Ionic Liquid Membranes.

    Science.gov (United States)

    Akhmetshina, Alsu A; Davletbaeva, Ilsiya M; Grebenschikova, Ekaterina S; Sazanova, Tatyana S; Petukhov, Anton N; Atlaskin, Artem A; Razov, Evgeny N; Zaripov, Ilnaz I; Martins, Carla F; Neves, Luísa A; Vorotyntsev, Ilya V

    2015-12-30

    Microporous polymers based on anionic macroinitiator and toluene 2,4-diisocyanate were used as a support for 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim][PF₆]) and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([emim][Tf₂N]) immobilization. The polymeric support was modified by using silica particles associated in oligomeric media, and the influence of the modifier used on the polymeric structure was studied. The supported ionic liquid membranes (SILMs) were tested for He, N₂, NH₃, H₂S, and CO₂ gas separation and ideal selectivities were calculated. The high values of ideal selectivity for ammonia-based systems with permanent gases were observed on polymer matrixes immobilized with [bmim][PF₆] and [emim][Tf₂N]. The modification of SILMs by nanosize silica particles leads to an increase of NH₃ separation relatively to CO₂ or H₂S.

  20. Synthesis and Crystal Structure of A New Armed-tetraazacrown Ether and Its Liquid Membrane Transport of Alkali Metal Cations

    Institute of Scientific and Technical Information of China (English)

    马淑兰; 朱文祥; 董淑静; 郭倩玲; 佘远斌

    2003-01-01

    A new tetra-N-substituted tetraazacrown ether derivative, 4,7,13,16-tetra ( 2-cyanobenzyl)-1, 10-dioxa-4, 7, 13, 16-tetraazacy-dooctademne, C44H48N8O2, has been synthesized and struc-turally characterized. It crystallizes in the monoclinic system,Slmeegroup P21/c with a = 1.1176(3) nm, b =2.1906(7) nm,c=0.8430(3)nm, V=2.0132(10)nm3, β = 102.740(5)°,Z=4, Dc= 1.189 g/cm3, final R1=0.0460, wR2=0.0803.The liquid membrane transports of alkali metal cations using the new macrocyde as the ion-carrier were also studied. Com-pared with some macrocyclic ligands, our newly synthesized lig.and showed a good selectivity ratio for Na Na+/Li+.

  1. The Effect of Microporous Polymeric Support Modification on Surface and Gas Transport Properties of Supported Ionic Liquid Membranes

    Directory of Open Access Journals (Sweden)

    Alsu A. Akhmetshina

    2015-12-01

    Full Text Available Microporous polymers based on anionic macroinitiator and toluene 2,4-diisocyanate were used as a support for 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim][PF6] and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonylimide ([emim][Tf2N] immobilization. The polymeric support was modified by using silica particles associated in oligomeric media, and the influence of the modifier used on the polymeric structure was studied. The supported ionic liquid membranes (SILMs were tested for He, N2, NH3, H2S, and CO2 gas separation and ideal selectivities were calculated. The high values of ideal selectivity for ammonia-based systems with permanent gases were observed on polymer matrixes immobilized with [bmim][PF6] and [emim][Tf2N]. The modification of SILMs by nanosize silica particles leads to an increase of NH3 separation relatively to CO2 or H2S.

  2. A moving boundary problem and orthogonal collocation in solving a dynamic liquid surfactant membrane model including osmosis and breakage

    Directory of Open Access Journals (Sweden)

    E.C. Biscaia Junior

    2001-06-01

    Full Text Available A dynamic kinetic-diffusive model for the extraction of metallic ions from aqueous liquors using liquid surfactant membranes is proposed. The model incorporates undesirable intrinsic phenomena such as swelling and breakage of the emulsion globules that have to be controlled during process operation. These phenomena change the spatial location of the chemical reaction during the course of extraction, resulting in a transient moving boundary problem. The orthogonal collocation method was used to transform the partial differential equations into an ordinary differential equation set that was solved by an implicit numerical routine. The model was found to be numerically stable and reliable in predicting the behaviour of zinc extraction with acidic extractant for long residence times.

  3. Fabrication of single-grain GdBa2Cu3O7− bulk superconductors with a new kind of liquid source by the top seeded infiltration and growth technique

    Indian Academy of Sciences (India)

    Guo-Zheng Li; Wan-Min Yang; Xiao-Fang Cheng; Jing Fan; Xiao-Dan Guo

    2010-05-01

    Compared to the conventional melt growth (MG) method, the top seeded infiltration and growth (TSIG) process is an effective way for preparing bulk REBa2Cu3O7− (RE-123) with finely dispersed RE2BaCuO5 (RE-211) particles. However, it is more complicated and time-consuming, because three kinds of precursor powders, namely, RE-211, RE-123 and BaCuO2, have to be prepared for the conventional TSIG process. In this paper, a new liquid source (NLS) composed of RE-211 and Ba3Cu5O8, was proposed for simplifying the TSIG process, which is different from the regular liquid source (RLS) composed of RE-123 and Ba3Cu5O8. In this modified TSIG technique, we need to prepare only RE-211 and BaCuO2 powders. Single-grain GdBa2Cu3O7− (GdBCO) bulk super-conductors have been fabricated using the RLS and NLS separately. The morphology, microstructure and levitation force of the bulk GdBCO have also been investigated. The results indicate that the NLS can be used to simplify the process flow and improve the efficiency on the fabrication of single-grain GdBCO superconductors.

  4. Hollow fiber membrane-coated functionalized polymeric ionic liquid capsules for direct analysis of estrogens in milk samples.

    Science.gov (United States)

    Feng, Juanjuan; Sun, Min; Bu, Yanan; Luo, Chuannan

    2016-02-01

    Protein removal process is always time-consuming for the analysis of milk samples. In this work, hollow fiber membrane-coated functionalized polymeric ionic liquid (HF-PIL) capsules were synthesized and used as solid-phase microextraction (SPME) sorbent for direct analysis of estrogens in milk samples. The functionalized PIL monolith sorbent was obtained by copolymerization between 1-(3-aminopropyl)-3-(4-vinylbenzyl)imidazolium 4-styrenesulfonate IL monomer and 1,6-di(3-vinylimidazolium) hexane bishexafluorophosphate IL-crosslinking agent. A group of four capsules were installed as SPME device, to determine four kinds of estrogens (estrone, diethylstilbestrol, hexestrol, and 17α-ethynylestradiol) in milk samples, coupled to high performance liquid chromatography. Extraction and desorption conditions were optimized to get satisfactory extraction efficiency. Good linearity was obtained in the range of 5-200 μg L(-1). The limits of detection were 1 μg L(-1) for diethylstilbestrol and 2 μg L(-1) for 17α-ethynylestradiol, estrone, and hexestrol. The present method was applied to analyze the model analytes in different milk samples. Relative recoveries were in the range of 85.5-112%. The HF-PIL SPME capsules showed satisfactory extraction efficiency and high resistance to sample matrix interference.

  5. Mathematical modeling of a carrier-mediated transport process in a liquid membrane.

    Science.gov (United States)

    Ganesan, Subramanian; Anitha, Shanmugarajan; Subbiah, Alwarappan; Rajendran, Lakshmanan

    2013-06-01

    An analysis of the reaction diffusion in a carrier-mediated transport process through a membrane is presented. A simple approximate analytical expression of concentration profiles is derived in terms of all dimensionless parameters. Furthermore, in this work we employ the homotopy perturbation method to solve the nonlinear reaction-diffusion equations. Moreover, the analytical results have been compared to the numerical simulation using the Matlab program. The simulated results are comparable with the appropriate theories. The results obtained in this work are valid for the entire solution domain.

  6. EXPERIMENTAL STUDY ON THE GAS-LIQUID FLOW IN THE MEMBRANE MICROPORE AERATION BIOREACTOR

    Directory of Open Access Journals (Sweden)

    DONG LIU

    2008-12-01

    Full Text Available Particle Image Velocimetry (PIV has been developed to measure the typical two-phase flow of various work conditions in Membrane Micropore Aeration Bioreactor (MMAB. The fluid phase is separated out using image processing techniques, which provides accurate measurements for the Bioreactor’s flow field, and makes it possible for quantitative analysis of the momentum exchange, heat exchange and the process of micro-admixture. The experimental method PIV used in this paper can preferably measure the complex flow in the reactor and initiates a new approach for the bioreactor design which mainly depends on experience at present.

  7. Novel diglycolamide functionalized calix[4]arenes for actinide extraction and supported liquid membrane studies: Part II. Role of substituents in the pendent arms and mass transfer modeling I

    NARCIS (Netherlands)

    Ansari, S.A.; Mohapatra, P.K.; Iqbal, M.; Kandwal, P.; Huskens, J.; Verboom, W.

    2013-01-01

    Several calix[4]arene-functionalized diglycolamide (C4DGA) ligands were evaluated for the extraction as well as supported liquid membrane (SLM) transport of actinides and fission product elements from nitric acid feed solutions. The extraction efficiency of the C4DGA ligands for Am(III) was orders o

  8. Mechanical spectra of glass-forming liquids. I. Low-frequency bulk and shear moduli of DC704 and 5-PPE measured by piezoceramic transducers

    DEFF Research Database (Denmark)

    Hecksher, Tina; Olsen, Niels Boye; Nelson, Keith Adam;

    2013-01-01

    We present dynamic shear and bulk modulus measurements of supercooled tetraphenyl-tetramethyl-trisiloxane (DC704) and 5-phenyl-4-ether over a range of temperatures close to their glass transition. The data are analyzed and compared in terms of time-temperature superposition (TTS), the relaxation...... time, and the spectral shape parameters. We conclude that TTS is obeyed to a good approximation for both the bulk and shear moduli. The loss-peak shapes are nearly identical, while the shear modulus relaxes faster than the bulk modulus. The temperature dependence of this decoupling of time scales...... is constant over the temperature range explored here. In addition, we demonstrate how one can measure reliably the DC shear viscosity over ten orders of magnitude by using the two measuring techniques in combination....

  9. Joining of Ion Transport Membranes Using a Novel Transient Liquid Phase Process

    Energy Technology Data Exchange (ETDEWEB)

    Darryl P. Butt

    2006-08-30

    The feasibility of a novel transient liquid phase (TLP) joining method has been demonstrated in joining La{sub 0.9}Ca{sub 0.1}FeO{sub 3} materials. Metal oxide powders were processed to form the TLP compositions which were used in the joining process. The method has been successful in producing joint interfaces that effectively disappear, as they are the same material and have the same properties as the joined parts. The feasibility of the method has been demonstrated for a single system, but many systems where the method can potentially be applied have been identified.

  10. Evaluation of sphingomyelin, cholester, and phosphatidylcholine-based immobilized artificial membrane liquid chromatography to predict drug penetration across the blood-brain barrier.

    Science.gov (United States)

    De Vrieze, Mike; Verzele, Dieter; Szucs, Roman; Sandra, Pat; Lynen, Frédéric

    2014-10-01

    Over the past decades, several in vitro methods have been tested for their ability to predict drug penetration across the blood-brain barrier. So far, in high-performance liquid chromatography, most attention has been paid to micellar liquid chromatography and immobilized artificial membrane (IAM) LC. IAMLC has been described as a viable approach, since the stationary phase emulates the lipid environment of a cell membrane. However, research in IAMLC has almost exclusively been limited to phosphatidylcholine (PC)-based stationary phases, even though PC is only one of the lipids present in cell membranes. In this article, sphingomyelin and cholester stationary phases have been tested for the first time towards their ability to predict drug penetration across the blood-brain barrier. Upon comparison with the PC stationary phase, the sphingomyelin- and cholester-based columns depict similar predictive performance. Combining data from the different stationary phases did not lead to improvements of the models.

  11. Hybrid flow analyzer for automatic hollow-fiber-assisted ionic liquid-based liquid-phase microextraction with in-line membrane regeneration.

    Science.gov (United States)

    Nitiyanontakit, Sira; Varanusupakul, Pakorn; Miró, Manuel

    2013-04-01

    The proof-of-concept of a new methodology for in-line hollow-fiber (HF)-assisted three-phase liquid-phase microextraction (LPME) allowing for handling of the feed and acceptor aqueous solutions and of minute volumes of the organic extracting phase in a programmable flow mode is reported in this paper. The flow analyzer fosters in-line anchoring of ionic-liquid-laden extracting solution (10 % (v/v) methyltrioctyl ammonium chloride in kerosene) in the pores of a single-strand microporous polypropylene HF, and regeneration of the liquid-phase membrane itself for each individual analysis cycle in a fully automated mode. Using hexavalent chromium as a model analyte and 1,5-diphenylcarbazide as a chromogenic probe in the acceptor solution, the flow-based HF-LPME hyphenated system was harnessed to the clean-up of troublesome samples (viz., domestic wastewater and soil leachates) with concomitant enrichment of target species. Distinct extraction modes and chemistries were assessed for enhanced Cr(VI) permeability. A single sample plug was subjected to a twofold backward-forward flow extraction so as to decrease the thickness of the boundary layer at the HF shell side for improved extraction efficiency. Under the optimized physicochemical variables, a limit of detection of 4.6 μg L(-1) Cr(VI), a dynamic linear range of up to 500 μg L(-1) and intermediate precision better than 10 % were obtained for a sample volume of 2.8 mL buffered at pH 4 and a volume of organic extractant of 120 μL, with an enrichment factor of ca. 11 for a sample residence time in the donor compartment of merely 4.5 min. Analyte recoveries in domestic wastewaters were ≥83 % using external calibration with relative standard deviations better than 14 %, thereby demonstrating the expedient clean-up of samples with elevated content of dissolved organic carbon. The automatic HF-LPME method was validated in terms of bias against the SRM 2701 (NIST soil) preceded by the EPA alkaline digestion method 3060A

  12. Liquid and Gas Permeation Studies on the Structure and Properties of Polyamide Thin-Film Composite Membranes

    KAUST Repository

    Duan, Jintang

    2014-11-01

    This research was undertaken to improve the understanding of structure-property-performance relationships in crosslinked polyamide (PA) thin-film composite (TFC) membranes as characterized by liquid and gas permeation studies. The ultrathin PA selective layer formed by interfacial polymerization between meta-phenylene diamine and trimesoyl chloride was confirmed to contain dense polymer matrix regions and defective regions in both dry and hydrated states. The first part of this research studied the effect of non-selective convection through defective regions on water flux and solute flux in pressure-assisted forward osmosis (PAFO). Through systematic comparison with cellulose triacetate (CTA) and PEBAX-coated PA-TFC membranes, the existence of defects in pristine, hydrated PA-TFC membranes was verified, and their effects were quantified by experimental and modeling methods. In the membrane orientation of selective layer facing the draw solution, water flux increases of up to 10-fold were observed to result from application of low hydraulic pressure (1.25 bar). Convective water flux through the defects was low (< 1% of total water flux for PA-TFC membranes) and of little consequence in practical FO or reverse osmosis (RO) applications. However, it effectively mitigated the concentration polarization in PAFO and therefore greatly increased the diffusive flux through the dense regions. The second part of this research characterized the structures of the PA material and the PA selective layer by gas adsorption and gas permeation measurements. Gas adsorption isotherms (N2 at 77K, CO2 at 273K) confirmed the microporous nature of PA in comparison with dense CTA and polysulfone materials. Gas permeation through the commercial PA-TFC membranes tested occurred primarily in the defective regions, resulting in Knudsen gas selectivity for various gas pairs. Applying a Nafion coating layer effectively plugged the defects and allowed gas permeation through the dense PA regions

  13. Dynamics of ionic liquids in bulk and in confinement by means of (1)H NMR relaxometry - BMIM-OcSO4 in an SiO2 matrix as an example.

    Science.gov (United States)

    Kruk, Danuta; Wojciechowski, Milosz; Brym, Szczepan; Singh, Rajendra Kumar

    2016-08-17

    (1)H nuclear magnetic resonance relaxometry is applied to reveal information on the translational and rotational dynamics of the ionic liquid: 1-butyl-3-methyl imidazoliumoctyl sulfate (BMIM-OcSO4) in bulk and in a confinement formed by a nanoporous SiO2 matrix. The experimental studies were performed in a very broad frequency range, from 8 kHz to 40 MHz (referring to the (1)H resonance frequency), in order to probe motional processes at very different time scales using a single experiment, and in the temperature range of 243-303 K. The relaxation results for BMIM-OcSO4 in bulk are interpreted in terms of three relaxation contributions: a term associated with the translational dynamics of the ions (it has been assumed that the translational dynamics of cations and anions can be described by one diffusion coefficient) and two terms associated with the rotational motion of the anion and the cation, respectively. The relationships between the obtained dynamic parameters (rotational correlation times and translational diffusion coefficients) are thoroughly discussed and used as a "reference" for the dynamics of BMIM-OcSO4 confined in an SiO2 matrix. Analysis of the corresponding relaxation data for the confined liquid shows that the confinement does not significantly affect the rotational dynamics, but it has a considerable impact on the translational motion. It is demonstrated that the relaxation term associated with the translational dynamics stems from two contributions: a contribution from a core (bulk-like) fraction of the liquid and from a fraction moving near the pore surface and therefore being for some time adsorbed on the pore walls. The translational diffusion coefficient for the last fraction is determined and several conclusions regarding the residence lifetime of the ions on the surface are drawn. Moreover, an additional motional process on the timescale of ns or shorter is revealed in the confinement.

  14. Progress of Supported Ionic Liquid Membrane Technology in Gas Separation%离子液体支撑液膜技术及其在气体分离中的研究进展

    Institute of Scientific and Technical Information of China (English)

    李红海; 徐保明; 李建隆

    2012-01-01

    分析离子液体支撑液膜的气体分离机理,总结目前离子液体支撑液膜的制备方法以及不同膜材料、不同离子液体及其亲疏水性对离子液体支撑液膜稳定性的影响.介绍离子液体支撑液膜在气体分离中的应用,对离子液体支撑液膜的工业化前景进行了展望.%The gas separation mechanism of supported ionic liquid membranes was analyzed. The ways for ionic liquid used as liquid phase in supported liquid membranes and the effects of different materials of membrane, different kinds of ionic liquids, hydrophilic and hydrophobic of membrane on the instability of supported ionic liquids membrane were summarized. The application of supported ionic liquid membranes in gas separation were reviewed. In the end, the prospects for the industrialization of supported liquid membranes were presented.

  15. A new optical method of continuously analysing the surface properties of a single pendant drop while obtaining quality bulk spectral and refractive index measurements of the liquid-under-test

    Energy Technology Data Exchange (ETDEWEB)

    McMillan, N D; O' Rourke, B; Morrin, D; Pringuet, P; Carbery, D [Institute of Technology Carlow, Kilkenny Road, Carlow (Ireland); Smith, S R P [Physics Department, University of Essex, Wivenhoe Park, Colchester, Essex CO4 3SQ (United Kingdom); O' Neill, M; Riedel, S [Carl Stuart Ltd., Whitestown Business Park, Tallaght, Dublin 24 (Ireland); Hammond, J, E-mail: norman.mcmillan@itcarlow.i [Starna Scientific Ltd., 52-53 Fowler Road, Hainault, Essex IG6 3UT (United Kingdom)

    2009-07-01

    The classical stalagmometer has been replaced by the tensiometer to measure surface properties from drop volume. From the drop period T{sub 1}, converted into volume, the surface properties of the liquid can be obtained. In the fibre drop analyser the use of the graphical signal (tensiotrace), significantly extends the measurement potential of the tensiometer by providing additional measurands. This instrument produces a series of peaks. The third-order reflection is known as 'the tensiopeak-period' t{sub 3}, and accurately predicts the value of the drop period. The results of an experimental study confirm the relationship between T{sub 1} and t{sub 3} for a wide range of liquids and are supported by ray-tracing modeling. Very sensitive and high quality bulk UV-visible spectra and refractive index measurements can be obtained from the drop-under-test.

  16. Small interfering ribonucleic acid induces liquid-to-ripple phase transformation in a phospholipid membrane

    Energy Technology Data Exchange (ETDEWEB)

    Choubey, Amit; Nomura, Ken-ichi; Kalia, Rajiv K.; Nakano, Aiichiro; Vashishta, Priya [Collaboratory for Advanced Computing and Simulations, Department of Physics and Astronomy, Department of Computer Science, Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California 90089-0242 (United States)

    2014-09-15

    Small interfering ribonucleic acid (siRNA) molecules play a pivotal role in silencing gene expression via the RNA interference mechanism. A key limitation to the widespread implementation of siRNA therapeutics is the difficulty of delivering siRNA-based drugs to cells. Here, we examine changes in the structure and dynamics of a dipalmitoylphosphatidylcholine bilayer in the presence of a siRNA molecule and mechanical barriers to siRNA transfection in the bilayer. Our all-atom molecular dynamics simulation shows that siRNA induces a liquid crystalline-to-ripple phase transformation in the bilayer. The ripple phase consists of a major region of non-interdigitated and a minor region of interdigitated lipid molecules with an intervening kink. In the ripple phase, hydrocarbon chains of lipid molecules have large compressive stresses, which present a considerable barrier to siRNA transfection.

  17. Small interfering ribonucleic acid induces liquid-to-ripple phase transformation in a phospholipid membrane

    Science.gov (United States)

    Choubey, Amit; Nomura, Ken-ichi; Kalia, Rajiv K.; Nakano, Aiichiro; Vashishta, Priya

    2014-09-01

    Small interfering ribonucleic acid (siRNA) molecules play a pivotal role in silencing gene expression via the RNA interference mechanism. A key limitation to the widespread implementation of siRNA therapeutics is the difficulty of delivering siRNA-based drugs to cells. Here, we examine changes in the structure and dynamics of a dipalmitoylphosphatidylcholine bilayer in the presence of a siRNA molecule and mechanical barriers to siRNA transfection in the bilayer. Our all-atom molecular dynamics simulation shows that siRNA induces a liquid crystalline-to-ripple phase transformation in the bilayer. The ripple phase consists of a major region of non-interdigitated and a minor region of interdigitated lipid molecules with an intervening kink. In the ripple phase, hydrocarbon chains of lipid molecules have large compressive stresses, which present a considerable barrier to siRNA transfection.

  18. Design and performance of BNR activated sludge systems with flat sheet membranes for solid-liquid separation.

    Science.gov (United States)

    du Toit, G J G; Ramphao, M C; Parco, V; Wentzel, M C; Ekama, G A

    2007-01-01

    The use of immersed membranes for solid-liquid separation in biological nutrient removal activated sludge (BNRAS) systems was investigated at lab scale. Two laboratory-scale BNR activated sludge systems were run in parallel, one a MBR system and the other a conventional system with secondary settling tanks. Both systems were in 3 reactor anaerobic, anoxic, aerobic UCT configurations. The systems were set up to have, as far as possible, identical design parameters such as reactor mass fractions, recycles and sludge age. Differences were the influent flow and total reactor volumes, and the higher reactor concentrations in the MBR system. The performances of the two systems were extensively monitored and compared to identify and quantify the influence of the membranes on system response. The MBR UCT system exhibited COD, FSA, TKN, TP and TSS removals that were consistently equivalent or superior to the conventional system. Better P removal in the MBR was attributed to lower observed P uptake in the anoxic zone. High nitrate loads to the anoxic reactor appeared to be the determining factor in stimulating P uptake. The MBR UCT system had a greater sludge production than the conventional system. This was partly attributable to the retention of all solids in the MBR reactor. For steady state design this increase is accommodated by increasing the influent unbiodegradable particulate COD fraction. Additionally an attempt was made to determine the Alpha values in the oxygen transfer rate. This paper briefly summarises and compares the results from both systems, and the conclusions that can be drawn from these results.

  19. Selective Ion Transporting Polymerized Ionic Liquid Membrane Separator for Enhancing Cycle Stability and Durability in Secondary Zinc-Air Battery Systems.

    Science.gov (United States)

    Hwang, Ho Jung; Chi, Won Seok; Kwon, Ohchan; Lee, Jin Goo; Kim, Jong Hak; Shul, Yong-Gun

    2016-10-05

    Rechargeable secondary zinc-air batteries with superior cyclic stability were developed using commercial polypropylene (PP) membrane coated with polymerized ionic liquid as separators. The anionic exchange polymer was synthesized copolymerizing 1-[(4-ethenylphenyl)methyl]-3-butylimidazolium hydroxide (EBIH) and butyl methacrylate (BMA) monomers by free radical polymerization for both functionality and structural integrity. The ionic liquid induced copolymer was coated on a commercially available PP membrane (Celguard 5550). The coat allows anionic transfer through the separator and minimizes the migration of zincate ions to the cathode compartment, which reduces electrolyte conductivity and may deteriorate catalytic activity by the formation of zinc oxide on the surface of the catalyst layer. Energy dispersive X-ray spectroscopy (EDS) data revealed the copolymer-coated separator showed less zinc element in the cathode, indicating lower zinc crossover through the membrane. Ion coupled plasma optical emission spectroscopy (ICP-OES) analysis confirmed over 96% of zincate ion crossover was reduced. In our charge/discharge setup, the constructed cell with the ionic liquid induced copolymer casted separator exhibited drastically improved durability as the battery life increased more than 281% compared to the pure commercial PP membrane. Electrochemical impedance spectroscopy (EIS) during the cycle process elucidated the premature failure of cells due to the zinc crossover for the untreated cell and revealed a substantial importance must be placed in zincate control.

  20. Preliminary characterization of carbon dioxide transfer in a hollow fiber membrane module as a possible solution for gas-liquid transfer in microgravity conditions

    Science.gov (United States)

    Farges, Bérangère; Duchez, David; Dussap, Claude-Gilles; Cornet, Jean-François

    2012-01-01

    In microgravity, one of the major challenge encountered in biological life support systems (BLSS) is the gas-liquid transfer with, for instance, the necessity to provide CO2 (carbon source, pH control) and to recover the evolved O2 in photobioreactors used as atmosphere bioregenerative systems.This paper describes first the development of a system enabling the accurate characterization of the mass transfer limiting step for a PTFE membrane module used as a possible efficient solution to the microgravity gas-liquid transfer. This original technical apparatus, together with a technical assessment of membrane permeability to different gases, is associated with a balance model, determining thus completely the CO2 mass transfer problem between phases. First results are given and discussed for the CO2 mass transfer coefficient kLCO obtained in case of absorption experiments at pH 8 using the hollow fiber membrane module. The consistency of the proposed method, based on a gas and liquid phase balances verifying carbon conservation enables a very accurate determination of the kLCO value as a main limiting step of the whole process. Nevertheless, further experiments are still needed to demonstrate that the proposed method could serve in the future as reference method for mass transfer coefficient determination if using membrane modules for BLSS in reduced or microgravity conditions.

  1. Recovery of ammonia from domestic wastewater effluents as liquid fertilizers by integration of natural zeolites and hollow fibre membrane contactors.

    Science.gov (United States)

    Sancho, I; Licon, E; Valderrama, C; de Arespacochaga, N; López-Palau, S; Cortina, J L

    2017-04-15

    The integration of up-concentration processes to increase the efficiency of primary sedimentation, as a solution to achieve energy neutral wastewater treatment plants, requires further post-treatment due to the missing ammonium removal stage. This study evaluated the use of zeolites as a post-treatment step, an alternative to the biological removal process. A natural granular clinoptilolite zeolite was evaluated as a sorbent media to remove low levels (up to 100mg-N/L) of ammonium from treated wastewater using batch and fixed bed columns. After being activated to the Na-form (Z-Na), the granular zeolite shown an ammonium exchange capacity of 29±0.8mgN-NH4(+)/g in single ammonium solutions and 23±0.8mgN-NH4(+)/g in treated wastewater simulating up-concentration effluent at pH=8. The equilibrium removal data were well described by the Langmuir isotherm. The ammonium adsorption into zeolites is a very fast process when compared with polymeric materials (zeolite particle diffusion coefficient around 3×10(-12)m(2)/s). Column experiments with solutions containing 100mgN-NH4(+)/L provide effective sorption and elution rates with concentration factors between 20 and 30 in consecutive operation cycles. The loaded zeolite was regenerated using 2g NaOH/L solution and the rich ammonium/ammonia concentrates 2-3g/L in NaOH were used in a liquid-liquid membrane contactor system in a closed-loop configuration with nitric and phosphoric acid as stripping solutions. The ammonia recovery ratio exceeded 98%. Ammonia nitrate and di-ammonium phosphate concentrated solutions reached up to 2-5% wt. of N.

  2. Screening anti-tumor compounds from Ligusticum wallichii using cell membrane chromatography combined with high-performance liquid chromatography and mass spectrometry.

    Science.gov (United States)

    Zhang, Tao; Ding, Yuanyuan; An, Hongli; Feng, Liuxin; Wang, Sicen

    2015-07-14

    Tyrosine 367 Cysteine-fibroblast growth factor receptor 4 cell membrane chromatography combined with high-performance liquid chromatography and mass spectrometry was developed. Tyrosine 367 Cysteine-HEK293 cells were used as cell membrane stationary phase. Specificity and reproducibility of the cell membrane chromatography was evaluated using 1-tert-butyl-3-{2-[4-(diethylamino)butylamino]-6-(3,5-dimethoxyphenyl)pyrido[2,3-d]pyrimidin-7-yl}urea, Nimodipine and dexamethasone acetate. Then, anti-tumor components acting on Tyrosine 367 Cysteine-fibroblast growth factor receptor 4 were screened and identified from extracts of Ligusticum wallichii. Components from the extract were retained on the cell membrane chromatographic column. The retained fraction was directly eluted into high-performance liquid chromatography with mass spectrometry system for separation and identification. Finally, Levistolide A was identified as an active component from Ligusticum wallichii extracts. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide-formazan colorimetric assay revealed that Levistolide A inhibits proliferation of overexpressing the mutated receptor cells with dose-dependent manner. Phosphorylation of fibroblast growth factor receptor 4 was also decrease under Levistolide A treatment. Flex dock simulation verified that Levistolide A could bind with the tyrosine kinase domain of fibroblast growth factor receptor 4. Therefore, Levistolide A screened by the cell membrane chromatography combined with high-performance liquid chromatography and mass spectrometry can arrest cell growth. In conclusion, the two-dimensional high-performance liquid chromatography method can screen and identify potential anti-tumor ingredients which specifically act on the tyrosine kinase domain of the mutated fibroblast growth factor receptor 4. This article is protected by copyright. All rights reserved.

  3. Modeling and simulations of polymer electrolyte membrane fuel cells with poroelastic approach for coupled liquid water transport and deformation in the membrane

    OpenAIRE

    2010-01-01

    Performance degradation and durability of polymer electrolyte membrane (PEM) fuel cells depend strongly on transport and deformation characteristics of their components especially the polymer membrane. Physical properties of membranes, such as ionic conductivity and Young's modulus, depend on the water content that varies significantly with operating conditions and during transients. Recent studies indicate that cyclic transients may induce hygrothermal fatigue that leads to the ultimate fail...

  4. Effects of polymer structure on properties of sulfonated polyimide/protic ionic liquid composite membranes for nonhumidified fuel cell applications.

    Science.gov (United States)

    Yasuda, Tomohiro; Nakamura, Shin-ichiro; Honda, Yoshiyuki; Kinugawa, Kei; Lee, Seung-Yul; Watanabe, Masayoshi

    2012-03-01

    To investigate the effects of polymer structure on the properties of composite membranes including a protic ionic liquid, [dema][TfO] (diethylmethylammonium trifluoromethanesulfonate), for nonhumidified fuel cell applications, we synthesized sulfonated polyimides (SPIs) with different structures as matrix polymers, which have different magnitudes of ion-exchange capacities (IECs), different sequence distributions of ionic groups, and positions of sulfonate groups in the main chain or side chain. Despite having similar IECs, multiblock copolymer SPI and random copolymer SPI having sulfonate groups in the side chain exhibit higher ionic conductivity than random copolymer SPI having sulfonate groups in the main chain, indicating that the flexibility of sulfonic acid groups and the sequence distribution of ionic groups greatly affect the ion conduction. Atomic force microscopy observation revealed that the multiblock copolymer SPI forms more developed phase separation than the others. These results indicate that the flexibility of sulfonic acid groups and the connectivity of the ion conduction channel, which greatly depends on the sequence distribution, affect the ion conduction.

  5. Separation of zinc ( Ⅱ )by emulsion liquid membrane system%乳状液膜体系分离锌(Ⅱ)

    Institute of Scientific and Technical Information of China (English)

    周冬梅; 朱山东; 柳畅先

    2012-01-01

    The separation of zinc ( II ) by emulsion liquid membrane systems was studied. The systems of span80 ( sorbitan mo-nooleate)-SDS( sodium dodecyl sulfate) and span80-AOT( AerosolOT,2-ethyIhexyl succinate sodium sulfate)were compared. The impact of concentration of surfactants on the removal rate for zinc ion and the reagent in internal phase, the ratio of milk to water and oil phase to internal phase have been discussed respectively. The separation of zinc ion from coexistence components was tested.%研究了span80(失水山梨醇单油酸脂)-SDS(十二烷基磺酸钠)与span80-AOT(2-乙基己基琥珀酸酯磺酸钠)两种乳状液膜体系对锌(Ⅱ)分离效果的比较.分别讨论了液膜体系中表面活性剂和内相试剂浓度、乳水比和油内比对锌(Ⅱ)去除率的影响.试验了锌(Ⅱ)与共存组分的分离.

  6. Formation of inverse Chladni patterns at microscale by acoustic streaming on a silicon membrane immersed in a liquid

    Science.gov (United States)

    Poulain, Cedric; Vuillermet, Gael; Casset, Fabrice

    2015-11-01

    High frequency acoustics (in the MHz range) is known to be very efficient to handle micro particles or living cells in microfluidics by taking advantage of the acoustic radiation force. Here, we will show that low frequency (~ 50kHz) together with use ultra thin silicon plate can give rise to a micro streaming that enables to move particles at will. Indeed, by means of silicon membranes excited in the low ultrasound range, we show that it is possible to form inverse two-dimensional Chladni patterns of micro-beads in liquid. Unlike the well-known effect in a gaseous environment at macroscale, where gravity effects are generally dominant, leading particles towards the nodal regions of displacement, we will show that the micro scale streaming in the vicinity of the plate tends to gather particles in antinodal regions. Moreover, a symmetry breaking effect together with the streaming can trigger a whole rotation of the beads in the fluidic cavity. We demonstrate that it is possible to make the patterns rotate at a well defined angular velocity where beads actually jump from one acoustic trap to another.

  7. Supported liquid membrane-protected molecularly imprinted beads for micro-solid phase extraction of sulfonamides in environmental waters.

    Science.gov (United States)

    Díaz-Álvarez, M; Barahona, F; Turiel, E; Martín-Esteban, A

    2014-08-29

    In this work, molecularly imprinted polymer (MIP) beads have been prepared and evaluated for the development of a supported liquid membrane-protected micro-solid phase extraction method for the analysis of sulfonamides (SAs) in aqueous samples. The performance of MIP beads was firstly evaluated in cartridges by conventional solid-phase extraction for the simultaneous analysis of SAs. Afterward, beads were packed into a polypropylene hollow fiber protected by an organic solvent immobilized in the pores of the capillary wall. During the process, the analytes were extracted from the aqueous sample to the immobilized organic solvent and then selectively retained by the MIP beads located inside the capillary. The effect of various experimental parameters as sample pH, time and stirring-rate among others, were studied for the establishment of optimum rebinding conditions. Relative recoveries for all sulfonamides tested in river and reservoir water samples by the proposed method using 100mL water sample spiked with 50μg L-1 of each sulfonamide were within 70-120%, with a relative standard deviation (RSD) <10% (n=3). The detection limits (LODs) were within 0.2-3μgL(-1), depending upon the sulfonamide and the type of water used.

  8. High-throughput analysis of drugs in biological fluids by desorption electrospray ionization mass spectrometry coupled with thin liquid membrane extraction

    DEFF Research Database (Denmark)

    Rosting, Cecilie; Pedersen-Bjergaard, Stig; Hansen, Steen Honore'

    2013-01-01

    -30%. A reliability test was performed on 20 samples with methadone, amitriptyline, nortriptyline and pethidine in urine, showing that none of the samples having concentrations above the LOD were missed and no false positives were found. Diphenhydramine and one of its metabolites were detected in authentic samples...... of urine and saliva, and methadone was detected from a whole-blood sample spiked to a concentration of 100 ng mL(-1). The method has several advantages, such as extremely low price in consumables, the possibility of fast analysis of very crude biofluids such as whole blood and the potential for a very high......Biological fluids such as urine, saliva and whole blood were analyzed for contents of drugs by a new combination of desorption electrospray ionization mass spectrometry (DESI-MS) and thin liquid membrane extraction (TLME). Analytes from the sample were extracted into a thin liquid membrane...

  9. Detection of nuclear and membrane antigens by liquid-based cytology following long-term storage of d1 cells, karpas cells, and peripheral blood mononuclear cells.

    Science.gov (United States)

    Zappacosta, Roberta; Aiello, Francesca B; D'Antuono, Tommaso; Procopio, Antonio D; Durum, Scott K; Conti, Pio; Rosini, Sandra

    2011-01-01

    Immunofluorescence is the most frequently utilized technique to analyze protein expression. Fixed immunofluorescent cell suspensions, however, can only be stored for a week. We investigated whether liquid-based cytology could be used to detect antigens in cultured cells after a long storage period. Murine and human cells were fixed in PreservCyt solution, stored for various periods, and then used to perform an automated immunocytochemical analysis. Phosphorylation of the nuclear transcription factor Stat-5 induced by IL-7 was detected up to 4 months after IL-7 stimulation. Simultaneous nuclear positivity for the proliferation index MIB-1 and membrane positivity for the CD30 antigen were evident three months after fixation. Liquid-based cytology thus ensures long-lasting nuclear and membrane antigen immunoreactivity and permits the storage of cells from laborious experiments at room temperature for future analyses.

  10. Nonhumidified Fuel Cells Using N-Ethyl-N-methyl-pyrrolidinium Fluorohydrogenate Ionic Liquid-poly(Vinylidene Fluoride-Hexafluoropropylene Composite Membranes

    Directory of Open Access Journals (Sweden)

    Pisit Kiatkittikul

    2015-06-01

    Full Text Available Composite membranes consisting of N-ethyl-N-methylpyrrolidinium fluoro-hydrogenate (EMPyr(FH1.7F ionic liquid and poly(vinylidene fluoride hexafluoro-propylene (PVdF-HFP copolymer were successfully prepared in weight ratios of 5:5, 6:4, and 7:3 using a casting method. The prepared membranes possessed rough surfaces, which potentially enlarged the three-phase boundary area. The EMPyr(FH1.7F/PVdF-HFP (7:3 weight ratio composite membrane had an ionic conductivity of 41 mS·cm-1 at 120 °C. For a single cell using this membrane, a maximum power density of 103 mW·cm-2 was observed at 50 °C under non-humidified conditions; this is the highest power output that has ever been reported for fluorohydrogenate fuel cells. However, the cell performance decreased at 80 °C, which was explained by penetration of the softened composite membrane into gas diffusion electrodes to partially plug gas channels in the gas diffusion layers; this was verified by in situ a.c. impedance analysis and cross-sectional SEM images of the membrane electrode assembly.

  11. The liquid phase epitaxy approach for the successful construction of ultra-thin and defect-free ZIF-8 membranes: Pure and mixed gas transport study

    KAUST Repository

    Shekhah, Osama

    2014-01-01

    The liquid-phase epitaxy (LPE) method was effectively implemented to deliberately grow/construct ultrathin (0.5-1 μm) continuous and defect-free ZIF-8 membranes. Permeation properties of different gas pair systems (O 2-N2, H2-CO2, CO2-CH 4, C3H6-C3H8, CH 4-n-C4H10) were studied using the time lag technique. This journal is © The Royal Society of Chemistry.

  12. 液膜法提取绿原酸的实验研究%Experimental Research of Extracting Chlorogenic Acid by Liquid Membrane Method

    Institute of Scientific and Technical Information of China (English)

    李祝; 肖诗英; 万端极

    2011-01-01

    采用液膜法提取杜仲叶中绿原酸,通过正交实验对液膜制备工艺和绿原酸提取工艺进行了研究.结果表明,液膜制备的最佳工艺条件为:NaOH浓度4 mol·L-1、吐温-20质量分数8%、搅拌速度350 r·min-1 ;绿原酸提取的最佳工艺条件为:混合时间8 min、乳水比1 ∶ 2、搅拌速度100 r·min-1、油内比3∶1.液膜法实现了对绿原酸的提取和浓缩,为进一步开发利用绿原酸提供了依据.%Chlorogenic acid was extracted from Eucommia leaves by liquid membrane method. The preparation conditions of liquid membrane and the extraction conditions of chlorogenic acid were optimized by orthogonal experiment. The results showed that the optimum preparation conditions of liquid membrane were as follows: NaOH concentration of 4 mol · L-1 ,Tween-20 mass fraction of 8%, stirring speed of 350 r · Min-1 ,the optimum extraction conditions of chlorogenic acid were as follows:the mixing time of 8 min,the emulsion/external-phase ratio of 1 : 2,stirring speed of 100 r · Min-1 ,the oil/internal-phase ratio of 3:1. By liquid membrane method,the chlorogenic acid was extracted and concentrated successfully,and provided a basis for exploiting chlorogenic acid.

  13. Ionic liquid-impregnated agarose film two-phase micro-electrodriven membrane extraction (IL-AF-μ-EME) for the analysis of antidepressants in water samples.

    Science.gov (United States)

    Mohamad Hanapi, Nor Suhaila; Sanagi, Mohd Marsin; Ismail, Abd Khamim; Wan Ibrahim, Wan Aini; Saim, Nor'ashikin; Wan Ibrahim, Wan Nazihah

    2017-03-01

    The aim of this study was to investigate and apply supported ionic liquid membrane (SILM) in two-phase micro-electrodriven membrane extraction combined with high performance liquid chromatography-ultraviolet detection (HPLC-UV) for pre-concentration and determination of three selected antidepressant drugs in water samples. A thin agarose film impregnated with 1-hexyl-3-methylimidazolium hexafluorophosphate, [C6MIM] [PF6], was prepared and used as supported ionic liquid membrane between aqueous sample solution and acceptor phase for extraction of imipramine, amitriptyline and chlorpromazine. Under the optimized extraction conditions, the method provided good linearity in the range of 1.0-1000μgL(-1), good coefficients of determination (r(2)=0.9974-0.9992) and low limits of detection (0.1-0.4μgL(-1)). The method showed high enrichment factors in the range of 110-150 and high relative recoveries in the range of 88.2-111.4% and 90.9-107.0%, for river water and tap water samples, respectively with RSDs of ≤7.6 (n=3). This method was successfully applied to the determination of the drugs in river and tap water samples. It is envisaged that the SILM improved the perm-selectivity by providing a pathway for targeted analytes which resulted in rapid extraction with high degree of selectivity and high enrichment factor.

  14. Recovery of synthetic dye from simulated wastewater using emulsion liquid membrane process containing tri-dodecyl amine as a mobile carrier

    Energy Technology Data Exchange (ETDEWEB)

    Othman, N., E-mail: norasikin@cheme.utm.my [Faculty of Chemical Engineering, Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor (Malaysia); Zailani, S.N.; Mili, N. [Faculty of Chemical Engineering, Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor (Malaysia)

    2011-12-30

    Highlights: Black-Right-Pointing-Pointer The emulsion liquid membrane process for synthetic reactive dyes recovery was examined. Black-Right-Pointing-Pointer Mobile carriers of tri-dodycylamine and salicyclic acid was used in formulation to remove the reactive dyes from simulated wastewater. Black-Right-Pointing-Pointer Almost 100% of dye was extracted and recovered in receiving phase. Black-Right-Pointing-Pointer An electrical field was used to breakdown the emulsion to separate the liquid membrane and receiving/recovery phase. - Abstract: The extraction of Red 3BS reactive dye from aqueous solution was studied using emulsion liquid membrane (ELM). ELM is one of the processes that have very high potential in treating industrial wastewater consisting of dyes. In this research, Red 3BS reactive dye was extracted from simulated wastewater using tridodecylamine (TDA) as the carrier agent, salicyclic acid (SA) to protonate TDA, sodium chloride as the stripping agent, kerosene as the diluent and SPAN 80 as emulsifier. Experimental parameters investigated were salicyclic acid concentration, extraction time, SPAN 80 concentration, sodium chloride concentration, TDA concentration, agitation speed, homogenizer speed, emulsifying time and treat ratio. The results show almost 100% of Red 3BS was removed and stripped in the receiving phase at the optimum condition in this ELM system. High voltage coalesce was applied to break the emulsion hence, enables recovery of Red 3BS in the receiving phase.

  15. Novel amphiphilic polymeric ionic liquid-solid phase micro-extraction membrane for the preconcentration of aniline as degradation product of azo dye Orange G under sonication by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Cai, Mei-Qiang; Wei, Xiao-Qing; Du, Chun-Hui; Ma, Xu-Ming; Jin, Mi-Cong

    2014-07-04

    A novel amphiphilic polymeric ionic liquid membrane containing a hydrophilic bromide anion and a hydrophobic carbonyl group was synthesized in dimethylformamide (DMF) systems using the ionic liquid 1-butyl-3-vinylimidazolium bromide (BVImBr) and the methylmethacrylate (MMA) as monomers. The prepared amphiphilic ploy-methylmethacrylate-1-butyl-3-vinylimidazolium bromide (MMA-BVImBr) was characterized by a scanning electron microscope and an infrared spectrum instrument. The results of solid-phase micro-extraction membrane (SPMM) experiments showed that the adsorption capacity of membrane was about 0.76μgμg(-1) for aniline. Based on this, a sensitive method for the determination of trace aniline, as a degradation product of azo dye Orange G under sonication, was developed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The calibration curve showed a good linearity ranging from 0.5 to 10.0μgL(-1) with a correlation coefficient value of 0.9998. The limit of quantification was 0.5μgL(-1). The recoveries ranged from 90.6% to 96.1%. The intra- and inter-day relative standard deviations were less than 8.3% and 10.9%. The developed SPMM-LC-MS/MS method was used successfully for preconcentration of trace aniline produced during the sonication of Orange G solution.

  16. Capillary high-performance liquid chromatography/mass spectrometric analysis of proteins from affinity-purified plasma membrane.

    Science.gov (United States)

    Zhao, Yingxin; Zhang, Wei; White, Michael A; Zhao, Yingming

    2003-08-01

    Proteomics analysis of plasma membranes is a potentially powerful strategy for the discovery of proteins involved in membrane remodeling under diverse cellular environments and identification of disease-specific membrane markers. A key factor for successful analysis is the preparation of plasma membrane fractions with low contamination from subcellular organelles. Here we report the characterization of plasma membrane prepared by an affinity-purification method, which involves biotinylation of cell-surface proteins and subsequent affinity enrichment with strepavidin beads. Western blotting analysis showed this method was able to achieve a 1600-fold relative enrichment of plasma membrane versus mitochondria and a 400-fold relative enrichment versus endoplasmic reticulum, two major contaminants in plasma membrane fractions prepared by conventional ultracentrifugation methods. Capillary-HPLC/MS analysis of 30 microg of affinity-purified plasma membrane proteins led to the identification of 918 unique proteins, which include 16.4% integral plasma membrane proteins and 45.5% cytosol proteins (including 8.6% membrane-associated proteins). Notable among the identified membrane proteins include 30 members of ras superfamily, receptors (e.g., EGF receptor, integrins), and signaling molecules. The low number of endoplasmic reticulum and mitochondria proteins (approximately 3.3% of the total) suggests the plasma membrane preparation has minimum contamination from these organelles. Given the importance of integral membrane proteins for drug design and membrane-associated proteins in the regulation cellular behaviors, the described approach will help expedite the characterization of plasma membrane subproteomes, identify signaling molecules, and discover therapeutic membrane-protein targets in diseases.

  17. Molecular view on protein sorting into liquid-ordered membrane domains mediated by gangliosides and lipid anchors

    NARCIS (Netherlands)

    de Jong, Djurre H.; Lopez, Cesar A.; Marrink, Siewert J.

    2013-01-01

    We present results from coarse grain molecular dynamics simulations of mixed model membranes consisting of saturated and unsaturated lipids together with cholesterol, in which lipid-anchored membrane proteins are embedded. The membrane proteins studied are the peripherally bound H-Ras, N-Ras, and He

  18. Bulk Stable Isotope Analysis of Carbon from Solids and Liquids using an Elemental Analyzer Coupled to a Wavelength-Scanned Cavity Ring-Down Spectrophotometer

    Science.gov (United States)

    Saad, N.; Rella, C.; van Pelt, A.

    2009-04-01

    We report here on the novel employment of a small footprint Wavelength-Scanned Cavity Ring-Down Spectrometer (WS-CRDS) interfaced to an elemental analyzer for the measurement of the bulk isotopic carbon signature in plants and food products. The current system provides an inexpensive alternative with unparalleled ease-of-use as compared to standard methods using the more complex analytical instrumentation of isotope ratio mass spectrometry. A precision of carbon isotopic ratio measurements of less than 1 permil was achieved in minutes of measurement time. Such precision readily distinguishes the isotopic carbon signatures of a variety of environmental and agricultural products from different origins, providing information about food authenticity and climate changes effect on plant physiology.

  19. Liquid chromatographic method for the simultaneous determination of captopril, piroxicam, and amlodipine in bulk drug, pharmaceutical formulation, and human serum by programming the detector.

    Science.gov (United States)

    Sultana, Najma; Arayne, M Saeed; Ali, Saeeda Nadir

    2013-10-01

    A highly sensitive LC method with UV detection has been developed for the simultaneous determination of coadministered drugs captopril, piroxicam, and amlodipine in bulk drug, pharmaceutical formulations, and human serum at the isosbestic point (235 nm) and at individual λmax (220, 255, and 238 nm, respectively) by programming the detector with time to match the individual analyte's chromophore, which enhanced the sensitivity with linear range. The assay involved an isocratic elution of analytes on a Bondapak C18 (10 μm, 25 × 0.46 cm) column at ambient temperature using a mobile phase of methanol/water 80:20 at pH 2.9 and a flow rate of 1.0 mL/min. Linearity was found to be 0.25-25, 0.10-6.0, and 0.20-13.0 μg/mL with correlation coefficient >0.998 and detection limits of 7.39, 3.90, and 9.38 ng/mL, respectively, whereas calibration curves for wavelength-programmed analysis were 0.10-6.0, 0.04-2.56, and 0.10-10.0 μg/mL with correlation coefficient >0.998 and detection limits of 5.79, 2.68, and 3.87 ng/mL, respectively. All the validated parameters were in the acceptable range. The recovery of drugs was 99.32-100.39 and 98.65-101.96% in pharmaceutical formulation and human serum, respectively, at the isosbestic point and at individual λmax . This method is applicable for the analysis of drugs in bulk drug, tablets, serum, and in clinical samples without interference of excipients or endogenous serum components.

  20. Simultaneous micro-electromembrane extractions of anions and cations using multiple free liquid membranes and acceptor solutions.

    Science.gov (United States)

    Kubáň, Pavel; Boček, Petr

    2016-02-18

    Micro-electromembrane extractions (μ-EMEs) across free liquid membranes (FLMs) were applied to simultaneous extractions of anions and cations. A transparent narrow-bore polymeric tubing was filled with adjacent plugs of μL volumes of aqueous and organic solutions, which formed a stable five-phase μ-EME system. For the simultaneous μ-EMEs of anions and cations, aqueous donor solution was the central phase, which was sandwiched between two organic FLMs and two aqueous acceptor solutions. On application of electric potential, anions and cations in the donor solution migrated across the two FLMs and into the two peripheral acceptor solutions in the direction of anode and cathode, respectively. Visual monitoring of anionic (tartrazine) and cationic (phenosafranine) dye confirmed their simultaneous μ-EMEs and their rapid (in less than 5 min) transfers into anolyte and catholyte, respectively. The concept of simultaneous μ-EMEs was further examined with selected model analytes; KClO4 was used for μ-EMEs of inorganic anions and cations and ibuprofen and procaine for μ-EMEs of acidic and basic drugs. Quantitative analyses of the resulting acceptor solutions were carried out by capillary electrophoresis with capacitively coupled contactless conductivity detection (CE-C(4)D). Good extraction recoveries (91-94%) and repeatability of peak areas (≤6.3%) were achieved for 5 min μ-EMEs of K(+) and ClO4(-). Extraction recoveries and repeatability of peak areas for 5 min μ-EMEs of ibuprofen and procaine were also satisfactory and ranged from 35 to 63% and 7.6 to 11.3%, respectively. Suitability of the presented micro-extraction procedure was further demonstrated on simultaneous μ-EMEs with subsequent CE-C(4)D of ibuprofen and procaine from undiluted human urine samples.

  1. 聚离子液体/PVDF共混离子传导膜的制备与性能研究%Ion Conductive Membrane with Interpenetration Network (IPN) Prepared by PVDF/Poly(Ionic Liquid)s Blend

    Institute of Scientific and Technical Information of China (English)

    青格乐图; 刘平; 范永生; 徐冬清; 王保国

    2011-01-01

    Ionic liquids (ILs) are organic salts with low melting point (< 100℃), low flammability, negligible vapor pressure, high ionic conductivity and wide electrochemical window. Polymeric ionic liquids (PILs) are a class of ionic liquids that contain polymerizable groups such as double bonds. In this article, ion conductive membrane with interpenetration network (IPN) was prepared by using the polyvinylidene fluoride(PVDF) and PILs. The conductivity of the prepared membrane depends on the adding amount of ionic liquid, and also depends on the type of added ionic liquid. In addition, the adding amount of ionic liquids has a significant effect on the tensile strength of the prepared membrane. As the mass ratio of PILs to PVDF is 0.6, the membrane conductivity reaches 3.0× 10-3 S·cm-1, the tensile strength 17.38 N·mm-2.%以研究高电导率、高稳定性的新型离子传导膜为目标,为电池领域的应用奠定基础.通过选用同时具有双键和离子交换基团的离子液体单体,能够制备聚离子液体的新型离子传导膜材料.采用溶剂法将聚偏氟乙烯(PVDF)和离子液体(ILS)共混,在加温条件下使离子液体单体之间发生聚合反应,制得高分子互穿网络结构的离子传导膜.系统研究了制膜过程的成膜温度、离子液体浓度等条件对膜电导率、拉伸强度等性能的影响.结果表明PILs/PVDF共混膜具有较高电导率和拉伸强度,离子液体含量对膜性能有显著影响.当膜中PILs和PVDF的质量比为0.6时,膜电导率为3.0×10-3 S·cm-1,拉伸强度为17.38 N·mm-2.

  2. Thermal stability, complexing behavior, and ionic transport of polymeric gel membranes based on polymer PVdF-HFP and ionic liquid, [BMIM][BF4].

    Science.gov (United States)

    Shalu; Chaurasia, S K; Singh, R K; Chandra, S

    2013-01-24

    PVdF-HFP + IL(1-butyl-3-methylimidazolium tetrafluoroborate; [BMIM][BF(4)]) polymeric gel membranes containing different amounts of ionic liquid have been synthesized and characterized by X-ray diffraction, scanning electron microscopy, Fourier transform infrared (FTIR), differential scanning calorimetry, thermogravimetric analysis (TGA), and complex impedance spectroscopic techniques. Incorporation of IL in PVdF-HFP polymer changes different physicochemical properties such as melting temperature (T(m)), thermal stability, structural morphology, amorphicity, and ionic transport. It is shown by FTIR, TGA (also first derivative of TGA, "DTGA") that IL partly complexes with the polymer PVdF-HFP and partly remains dispersed in the matrix. The ionic conductivity of polymeric gel membranes has been found to increase with increasing concentration of IL and attains a maximum value of 1.6 × 10(-2) S·cm(-1) for polymer gel membrane containing 90 wt % IL at room temperature. Interestingly, the values of conductivity of membranes with 80 and 90 wt % of IL were higher than that of pure IL (100 wt %). The polymer chain breathing model has been suggested to explain it. The variation of ionic conductivity with temperature of these gel polymeric membranes follows Arrhenius type thermally activated behavior.

  3. Synthesis and Characterisation of ETS-10/Acetate-based Ionic Liquid/Chitosan Mixed Matrix Membranes for CO2/N2 Permeation

    Directory of Open Access Journals (Sweden)

    Clara Casado-Coterillo

    2014-06-01

    Full Text Available Mixed matrix membranes (MMMs were prepared by incorporating organic surfactant-free hydrothermally synthesised ETS-10 and 1-ethyl-3-methylimidazolium acetate ionic liquid (IL to chitosan (CS polymer matrix. The membrane material characteristics and permselectivity performance of the two-component membranes were compared with the three-component membrane and the pure CS membrane. The addition of IL increased CO2 solubility of the polymer, and, thus, the CO2 affinity was maintained for the MMMs, which can be correlated with the crystallinity, measured by FT-IR, and void fraction calculations from differences between theoretical and experimental densities. The mechanical resistance was enhanced by the ETS-10 nanoparticles, and flexibility decreased in the two-component ETS-10/CS MMMs, but the flexibility imparted by the IL remained in three-component ETS-10/IL/CS MMMs. The results of this work provide insight into another way of facing the adhesion challenge in MMMs and obtain CO2 selective MMMs from renewable or green chemistry materials.

  4. Synthesis and Characterisation of ETS-10/Acetate-based Ionic Liquid/Chitosan Mixed Matrix Membranes for CO2/N2 Permeation.

    Science.gov (United States)

    Casado-Coterillo, Clara; Del Mar López-Guerrero, María; Irabien, Angel

    2014-06-19

    Mixed matrix membranes (MMMs) were prepared by incorporating organic surfactant-free hydrothermally synthesised ETS-10 and 1-ethyl-3-methylimidazolium acetate ionic liquid (IL) to chitosan (CS) polymer matrix. The membrane material characteristics and permselectivity performance of the two-component membranes were compared with the three-component membrane and the pure CS membrane. The addition of IL increased CO2 solubility of the polymer, and, thus, the CO2 affinity was maintained for the MMMs, which can be correlated with the crystallinity, measured by FT-IR, and void fraction calculations from differences between theoretical and experimental densities. The mechanical resistance was enhanced by the ETS-10 nanoparticles, and flexibility decreased in the two-component ETS-10/CS MMMs, but the flexibility imparted by the IL remained in three-component ETS-10/IL/CS MMMs. The results of this work provide insight into another way of facing the adhesion challenge in MMMs and obtain CO2 selective MMMs from renewable or green chemistry materials.

  5. Specific interface area and self-stirring in a two-liquid system experiencing intense interfacial boiling below the bulk boiling temperatures of both components

    CERN Document Server

    Goldobin, Denis S

    2016-01-01

    We present an approach to theoretical assessment of the mean specific interface area $(\\delta{S}/\\delta{V})$ for a well-stirred system of two immiscible liquids experiencing interfacial boiling. The assessment is based on the balance of transformations of mechanical energy and the laws of the momentum and heat transfer in the turbulent boundary layer. The theory yields relations between the specific interface area and the characteristics of the system state. In particular, this allows us to derive the equations of self-cooling dynamics of the system in the absence of external heat supply. The results provide possibility for constructing a self-contained mathematical description of the process of interfacial boiling. In this study, we assume the volume fractions of two components to be similar as well as the values of their kinematic viscosity and molecular heat diffusivity.

  6. Automation of static and dynamic non-dispersive liquid phase microextraction. Part 2: Approaches based on impregnated membranes and porous supports.

    Science.gov (United States)

    Alexovič, Michal; Horstkotte, Burkhard; Solich, Petr; Sabo, Ján

    2016-02-11

    A critical overview on automation of modern liquid phase microextraction (LPME) approaches based on the liquid impregnation of porous sorbents and membranes is presented. It is the continuation of part 1, in which non-dispersive LPME techniques based on the use of the extraction phase (EP) in the form of drop, plug, film, or microflow have been surveyed. Compared to the approaches described in part 1, porous materials provide an improved support for the EP. Simultaneously they allow to enlarge its contact surface and to reduce the risk of loss by incident flow or by components of surrounding matrix. Solvent-impregnated membranes or hollow fibres are further ideally suited for analyte extraction with simultaneous or subsequent back-extraction. Their use can therefore improve the procedure robustness and reproducibility as well as it "opens the door" to the new operation modes and fields of application. However, additional work and time are required for membrane replacement and renewed impregnation. Automation of porous support-based and membrane-based approaches plays an important role in the achievement of better reliability, rapidness, and reproducibility compared to manual assays. Automated renewal of the extraction solvent and coupling of sample pretreatment with the detection instrumentation can be named as examples. The different LPME methodologies using impregnated membranes and porous supports for the extraction phase and the different strategies of their automation, and their analytical applications are comprehensively described and discussed in this part. Finally, an outlook on future demands and perspectives of LPME techniques from both parts as a promising area in the field of sample pretreatment is given.

  7. Screening antiallergic components from Carthamus tinctorius using rat basophilic leukemia 2H3 cell membrane chromatography combined with high-performance liquid chromatography and tandem mass spectrometry.

    Science.gov (United States)

    Han, Shengli; Huang, Jing; Cui, Ronghua; Zhang, Tao

    2015-02-01

    Carthamus tinctorius, used in traditional Chinese medicine, has many pharmacological effects, such as anticoagulant effects, antioxidant effects, antiaging effects, regulation of gene expression, and antitumor effects. However, there is no report on the antiallergic effects of the components in C. tinctorius. In the present study, we investigated the antiallergic components of C. tinctorius and its mechanism of action. A rat basophilic leukemia 2H3/cell membrane chromatography coupled online with high-performance liquid chromatography and tandem mass spectrometry method was developed to screen antiallergic components from C. tinctorius. The screening results showed that Hydroxysafflor yellow A, from C. tinctorius, was the targeted component that retained on the rat basophilic leukemia 2H3/cell membrane chromatography column. We measured the amount of β-hexosaminidase and histamine released in mast cells and the key markers of degranulation. The release assays showed that Hydroxysafflor yellow A could attenuate the immunoglobulin E induced release of allergic cytokines without affecting cell viability from 1.0 to 50.0 μM. In conclusion, the established rat basophilic leukemia 2H3 cell membrane chromatography coupled with online high-performance liquid chromatography and tandem mass spectrometry method successfully screened and identified Hydroxysafflor yellow A from C. tinctorius as a potential antiallergic component. Pharmacological analysis elucidated that Hydroxysafflor yellow A is an effective natural component for inhibiting immunoglobulin E-antigen-mediated degranulation.

  8. Determination of pesticide residues in wine by membrane-assisted solvent extraction and high-performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Moeder, M; Bauer, C; Popp, P; van Pinxteren, M; Reemtsma, T

    2012-06-01

    The determination of pesticides in food products is an essential issue to guarantee food safety and minimise health risks of consumers. A protocol based on membrane-assisted solvent extraction and liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) that allows the determination of 18 pesticides in red wine at minimum labour effort for sample preparation was developed and validated. Ten millilitres of wine were extracted using 100 μL of toluene filled in a non-porous polyethylene membrane bag which is immersed in the wine sample. After 150 min extraction under stirring, an aliquot of the extraction solution is analysed using HPLC-MS/MS. The limits of quantification ranged from 3 ng/L for Pirimicarb to 1.33 μg/L for Imidacloprid. Quantification by matrix-matched calibration provided relative standard deviations ≤16 % for most of the target pesticides. The linearity of calibration was given over three to four orders of magnitude, which enables the reliable measurement of a broad range of pesticide concentrations, and for each target pesticide, the sensitivity of the protocol meets the maximum residue levels set by legislations at least for wine grapes. Good agreement of results was found when the new method was compared with a standard liquid-liquid extraction protocol. In five wine samples analysed, Carbendazim and Metalaxyl were determined at micrograms per litre concentrations, even in some of the organic wines. Tebuconazol and Cyprodinitril were determined at lower abundance and concentration, followed by Spiroxamin and Diuron.

  9. SIMULTANEOUS ESTIMATION OF ROSUVASTATIN CALCIUM AND CLOPIDOGREL BISULPHATE FROM BULK AND COMMERCIAL PRODUCTS USING A VALIDATED REVERSE PHASE HIGH PERFORMANCE LIQUID CHROMATOGRAPHIC TECHNIQUE

    Directory of Open Access Journals (Sweden)

    Avani Sheth

    2012-11-01

    Full Text Available A simple, rapid, accurate, precise and economical reverse phase high performance liquid chromatographic method is developed for simultaneous separation and quantification of two cardiovascular drugs, viz., Rosuvastatin Calcium and Clopidogrel Bisulphate. The separation of both the drugs was achieved on Novapak C18 column (100 x 3.9 mm, 4 µm column using a mobile phase of Sodium Perchlorate buffer solution (at pH 2.5: Acetonitrile (65:35 v/v. The flow rate was 1 ml/min and detection was done at 242 nm. The retention time for Rosuvastatin Calcium was 4.4 min and Clopidogrel Bisulphate was 7.6 min. Rosuvastatin Calcium and Clopidogrel Bisulphate showed a linear response in the concentration range of 10-60 µg/ml and 18.75 - 112.5 µg/ml respectively. The correlation co-efficients for Rosuvastatin Calcium and Clopidogrel Bisulphate were 0.9999 and 0.9999 respectively. The percentage recoveries obtained for Rosuvastatin Calcium and Clopidogrel Bisulphate ranges from 99.1% to 100.5% and 99.1% to 99.6% respectively. The results of analysis have been validated as per ICH guidelines. Validation results indicated that method shows satisfactory linearity, accuracy, precision and ruggedness. The extremely low flow rate, simple mobile phase composition makes this method cost effective, rapid, non-tedious and can also be successfully employed for simultaneous estimation of both drugs in commercial products.

  10. Development and Validation of Reverse-phase High-performance Liquid Chromatography Method for Estimation of Citicoline Sodium in Bulk and Dosage Form.

    Science.gov (United States)

    Maradiya, H K; Pansara, Vasundhara H

    2013-03-01

    A simple, accurate, precise and sensitive reverse-phase high-performance liquid chromatography method for the determination of citicoline sodium has been developed and validated. Drug was resolved on a C18 column (Phenomenex Luna, 250×4.6 mm, 10μ), utilizing mobile phase of potassium dihydrogen phosphate buffer and acetonitrile in a ratio of 30:70. Mobile phase was delivered at the flow rate of 1.0 ml/min and detection was carried out at 272 nm. Separation was completed within 2.22 min. Calibration curve was linear with good correlation coefficient (R(2)=0.999) over a concentration range 10-60 μg/ml. Recovery was between 98.84 and 101.76%. Method was found to be reproducible with relative standard deviation for intra and interday precision of <2.0% over the said concentration range. The method was successfully applied to the determination of the citicoline sodium, it can be very useful and an alternate to performing the stability studies.

  11. Development and validation of reverse-phase high-performance liquid chromatography method for estimation of citicoline sodium in bulk and dosage form

    Directory of Open Access Journals (Sweden)

    H K Maradiya

    2013-01-01

    Full Text Available A simple, accurate, precise and sensitive reverse-phase high-performance liquid chromatography method for the determination of citicoline sodium has been developed and validated. Drug was resolved on a C18 column (Phenomenex Luna, 250×4.6 mm, 10μ, utilizing mobile phase of potassium dihydrogen phosphate buffer and acetonitrile in a ratio of 30:70. Mobile phase was delivered at the flow rate of 1.0 ml/min and detection was carried out at 272 nm. Separation was completed within 2.22 min. Calibration curve was linear with good correlation coefficient (R 2 =0.999 over a concentration range 10-60 μg/ml. Recovery was between 98.84 and 101.76%. Method was found to be reproducible with relative standard deviation for intra and interday precision of <2.0% over the said concentration range. The method was successfully applied to the determination of the citicoline sodium, it can be very useful and an alternate to performing the stability studies.

  12. An easy method for the preparation of anion exchange membranes: Graft-polymerization of ionic liquids in porous supports

    NARCIS (Netherlands)

    Merle, Geraldine; Chairuna, Annisa; Ven, van de Erik; Nijmeijer, Kitty

    2013-01-01

    A novel way for anion exchange membrane (AEM) preparation has been investigated, avoiding the use of expensive and toxic chemicals. This new synthetic approach to prepare AEMs was based on the use of a porous polybenzylimidazole membrane as support in which functionalized ILs were introduced and sub

  13. Evaluation of nanofiltration membranes for treatment of liquid radioactive waste; Avaliacao de membranas de nanofiltracao para o tratamento de rejeito radioativo liquido

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Elizabeth Eugenio de Mello

    2013-07-01

    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{sub 6}) to uranium dioxide (UO{sub 2}) in the cycle of nuclear fuel. This waste contains about 7.0 mg L{sup -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)

  14. Di(2-ethylhexyl)phosphoric acid-coconut oil supported liquid membrane for the separation of copper ions from copper plating wastewater

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Permeation of Cu(II) from its aqueous solution through a supported liquid membrane (SLM) containing di(2-ethylhexyl)phosphoric acid (D2EHPA) carrier dissolved in coconut oil has been studied. The effects of Cu(II), pH (in feed), H2SO4 (stripping) and D2EHPA (in membrane) concentrations have been investigated. The stability of the D2EHPA-coconutoil has also been evaluated. High Cu(II) concentration in the feed leads to an increase in flux from 4.1 × 10-9 to 8.9 × 10-9 mol/(m2·s) within the Cu(II) concentration range 7.8×10-4-78.6×10-4 mol/L at pH of 4.0 in the feed and 12.4 × 10-4 mol/L D2EHPA in the membrane phase. Increase in H2SO4 concentration in strip solution leads to an increase in copper ions flux up to 0.25 mol/L H2SO4, providing a maximum flux of 7.4 × 10-9 mol/(m2·s). The optimum conditions for Cu(II) transport are, pH of feed 4.0, 0.25 mol/L H2SO4 in strip phase and 12.4 × 10-4 mol/L D2EHPA (membrane) in 0.5 (m pore size polytetrafluoroethylene (PTFE) membrane. It has been observed that Cu(II) flux across the membrane tends to increase with the concentration of copper ions. Application of the method developed to copper plating bath rinse solutions has been found to be successful in the recovery of Cu(II). rane. It

  15. Simultaneous estimation of olmesartan medoxomil and indapamide from bulk and commercial products using a validated reverse phase high performance liquid chromatographic technique

    Directory of Open Access Journals (Sweden)

    Avani Sheth

    2013-01-01

    Full Text Available Aim: A simple, rapid, accurate, precise and economical reverse phase high performance liquid chromatographicmethod is developed for simultaneous separation and quantification of two anti-hypertensive drugs, viz., olmesartan medoxomil and indapamide. Materials and Methods: The separation of both the drugs was achieved on ACE C 18 AR column (250 × 4.6 mm id, 5 μm particle size column using a mobile phase of sodium perchlorate and triethylamine buffer solution (at pH 3: Acetonitrile (60:40 v/v. The flow rate was 1 ml/min and detection was done at 280 nm. Results: The retention time for indapamide was 5.3 min and for olmesartan medoxomil was 6.8 min. Olmesartan medoxomil and indapamide showed a linear response in the concentration range of 50-300 μg/ml and 3.75-22.5 μg/ml respectively. The correlation co-efficients for olmesartan medoxomil and indapamide were 0.9999 and 0.9998 respectively. The percentage recoveries obtained forolmesartan medoxomil and indapamide ranges from 99.3% to 99.8% and 99.7% to 100.9% respectively. The results of the analysis have been validated as per International conference on Harmonisation (ICH guidelines. Validation results indicated that method shows satisfactory linearity, accuracy, precision, and ruggedness. Conclusion: The extremely low flow rate, simple mobile phase composition makes this method cost effective, rapid, and non-tedious and can also be successfully employed for simultaneous estimation of both drugs in commercial products.

  16. Liquid-phase membrane extraction of targeted pesticides from manufacturing wastewaters in a hollow fibre contactor with feed-stream recycle.

    Science.gov (United States)

    Đorđević, Jelena; Vladisavljević, Goran T; Trtić-Petrović, Tatjana

    2017-01-01

    A two-phase membrane extraction in a hollow fibre contactor with feed-stream recycle was applied to remove selected pesticides (tebufenozide, linuron, imidacloprid, acetamiprid and dimethoate) from their mixed aqueous solutions. The contactor consisted of 50 polypropylene hollow fibres impregnated with 5% tri-n-octylphosphine oxide in di-n-hexyl ether. For low-polar pesticides with log P ≥ 2 (tebufenozide and linuron), the maximum removal efficiency increased linearly from 85% to 96% with increasing the feed flow rate. The maximum removal efficiencies of more polar pesticides were significantly higher under feed recirculation (86%) than in a continuous single-pass operation (30%). It was found from the Wilson's plot that the mass transfer resistance of the liquid membrane can be neglected for low-polar pesticides. The pesticide removals from commercial formulations were similar to those from pure pesticide solutions, indicating that built-in adjuvants did not affect the extraction process.

  17. 乳化液膜法处理含Cr(Ⅲ)废水%TREATMENT OF Cr(Ⅲ) WASTE-WATER WITH EMULSION LIQUID MEMBRANE

    Institute of Scientific and Technical Information of China (English)

    余晓皎; 姚秉华; 周孝德

    2004-01-01

    The transfer behavior of Cr (Ⅲ) through the emulsion liquid membrane system of TBP-Span80-atoleine -kerosene was studied. The effects of membrane phase component, pH value in external phase,concentration of H2SO4 in internal phase, ratio of emulsion-water (Rew) and coexisting ions on the transport rate of Cr (Ⅲ) were investigated. The results showed that the transport rate of Cr (Ⅲ) could reach 99.5% under the optimun conditions of 7%TBP, 5% Span80, 4% atoleine, 84% kerosene, 1.0 mol·L-1 H2SO4 in internal phase and pH 3.5 in external phase. This method was applied to the treatment of Cr (Ⅲ) waste-water, and the residual concentration of Cr (Ⅲ) could be reduced to 1.0 mg·L-1 , which was below the national standard of waste-water discharge.

  18. Peptide mapping of /sup 125/I-labelled membrane protein of influenza viruses by reverse-phase high-performance liquid chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Darveau, A.; Lecomte, J. (Centre de Recherche en Virologie, Institut Armand-Frappier, Laval, Quebec (Canada)); Seidah, N.G.; Chretien, M. (Institut de Recherches Cliniques de Montreal, Montreal (Canada))

    1982-03-01

    The resolution potential of reverse-phase high-performance liquid chromatography (HPLC) for peptide analysis of hydrophobic viral membranes has been investigated, using as a model the membrane (M) protein of influenza virus. Proteolytic digests of /sup 125/I-labelled M protein CNBr fragments, extracted from radioiodinated whole virus, have been separated on a uBondapak C/sub 18/ column with an isopropanol or acetonitrile solvent system. Peptide mapping of trypsin digests of M protein from A/PR/8/34 (H1N1) and A/chicken/Germany/N/49 (H10N7) viruses was identical, whereas Staphylococcus aureus V8 protease digests showed minor differences in at least two peptides. The results also show that HPLC is a powerful tool for the separation of proteolytic digests of viral proteins, since the peptide maps are highly reproducible and recovery was always greater than 85%.

  19. Sustainable Process for the Preparation of High-Performance Thin-Film Composite Membranes using Ionic Liquids as the Reaction Medium.

    Science.gov (United States)

    Mariën, Hanne; Bellings, Lotte; Hermans, Sanne; Vankelecom, Ivo F J

    2016-05-23

    A new form of interfacial polymerization to synthesize thin-film composite membranes realizes a more sustainable membrane preparation and improved nanofiltration performance. By introducing an ionic liquid (IL) as the organic reaction phase, the extremely different physicochemical properties to those of commonly used organic solvents influenced the top-layer formation in several beneficial ways. In addition to the elimination of hazardous solvents in the preparation, the m-phenylenediamine (MPD) concentration could be reduced 20-fold, and the use of surfactants and catalysts became redundant. Together with the more complete recycling of the organic phase in the water/IL system, these factors resulted in a 50 % decrease in the mass intensity of the top-layer formation. Moreover, a much thinner top layer with a high ethanol permeance of 0.61 L m(-2)  h(-1)  bar(-1) [99 % Rose Bengal (RB, 1017 Da) retention; 1 bar=0.1 MPa] was formed without the use of any additives. This EtOH permeance is 555 and 161 % higher than that for the conventional interfacial polymerization (without and with additives, respectively). In reverse osmosis, high NaCl retentions of 97 % could be obtained. Finally, the remarkable decrease in the membrane surface roughness indicates the potential for reduced fouling with this new type of membrane.

  20. Maximising metal ions flux across a microdialysis membrane by incorporating poly-L-aspartic acid, poly-L-histidine, 8-hydroxyquinoline and ethylenediaminetetraacetic acid in the perfusion liquid

    Energy Technology Data Exchange (ETDEWEB)

    Mogopodi, Dikabo [University of Botswana, Department of Chemistry, Private Bag UB 00704, Gaborone (Botswana); Torto, Nelson [University of Botswana, Department of Chemistry, Private Bag UB 00704, Gaborone (Botswana)]. E-mail: torton@mopipi.ub.bw

    2005-04-08

    This paper presents a study of quiescent microdialysis sampling of Cr{sup 3+}, Cu{sup 2+}, Ni{sup 2+} and Pb{sup 2+} involving the incorporation of poly-L-aspartic acid, poly-L-histidine, 8-hydroxyquinoline (8-HQ) and ethylenediaminetetraacetic acid (EDTA), in the perfusion liquid as an approach to maximise metal analyte flux across the microdialysis membrane. These chelating agents were individually optimised with respect to microdialysis recovery and subsequently combined in the perfusion liquid. A combination of 20% (w/v) poly-L-histidine, 0.032% (w/v) poly-L-aspartic acid and 1 mM 8-HQ achieved microdialysis recovery up to 90%. Since 1 mM EDTA achieved recoveries greater than 80% for all metals understudy, EDTA was not combined with any of the chelating agents. Under the optimal conditions of maximum metal ion flux across the microdialysis membrane, metal ions from natural and wastewater were sampled and analysed with an electrothermal atomic absorption spectrometer equipped with a Zeeman background corrector. Results showed higher concentrations of detected metal ions after microdialysis sampling compared to direct detection without sample clean-up. Incorporation of chelating agents in the microdialysis perfusion liquid enhanced metal ions recovery in real samples and achieved enrichment factors of up to 42. The study demonstrated that combining chelating agents is a good approach towards maximising metal flux across the dialysis membrane. Given that recoveries between 80 and 90% were achieved under quiescent microdialysis sampling conditions, these findings are an important development for in vivo diagnostic sampling of metal ions.

  1. Application of hollow fiber supported liquid membrane as a chemical reactor for esterification of lactic acid and ethanol to ethyl lactate

    Energy Technology Data Exchange (ETDEWEB)

    Teerachaiyapat, Thanyarutt; Ramakul, Prakorn [Faculty of Engineering and Industrial Technology, Silpakorn University, Nakhon Pathom (Thailand)

    2016-01-15

    Hollow fiber supported liquid membrane was applied as a reactor to synthesize ethyl lactate from lactic acid. Lactic acid in the feed solution was extracted by tri-n-octylamine (TOA) and stripped by ethanol with p-toluene sulfonic acid acting as the catalyst to form ethyl lactate. Central composite design (CCD) was used to determine the significant factors and their interactions. The response surface was applied for optimization. An optimized yield of 30% was predicted and its validity was evaluated by comparison with experimental results at different concentrations of lactic acid in the feed solution, with good agreement achieved.

  2. Modulating alignment of membrane proteins in liquid-crystalline and oriented gel media by changing the size and charge of phospholipid bicelles

    Science.gov (United States)

    Lorieau, Justin L; Maltsev, Alexander S.; Louis, John M; Bax, Ad

    2013-01-01

    We demonstrate that alignment of a structured peptide or small protein solubilized in mixed phospholipid:detergent micelles or bicelles, when embedded in a compressed gel or liquid crystalline medium, can be altered by either changing the phospholipid aggregate shape, charge, or both together. For the hemagglutinin fusion peptide solubilized in bicelles, we show that bicelle shape and charge do not change its helical hairpin structure but impact its alignment relative to the alignment medium, both in charged compressed acrylamide gel and in liquid crystalline d (GpG). The method can be used to generate sets of residual dipolar couplings (RDCs) that correspond to orthogonal alignment tensors, and holds promise for high-resolution structural refinement and dynamic mapping of membrane proteins. PMID:23508769

  3. Modulating alignment of membrane proteins in liquid-crystalline and oriented gel media by changing the size and charge of phospholipid bicelles

    Energy Technology Data Exchange (ETDEWEB)

    Lorieau, Justin L.; Maltsev, Alexander S.; Louis, John M.; Bax, Ad, E-mail: bax@nih.gov [National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health, Laboratory of Chemical Physics (United States)

    2013-04-15

    We demonstrate that alignment of a structured peptide or small protein solubilized in mixed phospholipid:detergent micelles or bicelles, when embedded in a compressed gel or liquid crystalline medium, can be altered by either changing the phospholipid aggregate shape, charge, or both together. For the hemagglutinin fusion peptide solubilized in bicelles, we show that bicelle shape and charge do not change its helical hairpin structure but impact its alignment relative to the alignment medium, both in charged compressed acrylamide gel and in liquid crystalline d(GpG). The method can be used to generate sets of residual dipolar couplings that correspond to orthogonal alignment tensors, and holds promise for high-resolution structural refinement and dynamic mapping of membrane proteins.

  4. Modeling the Liquid Water Transport in the Gas Diffusion Layer for Polymer Electrolyte Membrane Fuel Cells Using a Water Path Network

    Directory of Open Access Journals (Sweden)

    Dietmar Gerteisen

    2013-09-01

    Full Text Available In order to model the liquid water transport in the porous materials used in polymer electrolyte membrane (PEM fuel cells, the pore network models are often applied. The presented model is a novel approach to further develop these models towards a percolation model that is based on the fiber structure rather than the pore structure. The developed algorithm determines the stable liquid water paths in the gas diffusion layer (GDL structure and the transitions from the paths to the subsequent paths. The obtained water path network represents the basis for the calculation of the percolation process with low calculation efforts. A good agreement with experimental capillary pressure-saturation curves and synchrotron liquid water visualization data from other literature sources is found. The oxygen diffusivity for the GDL with liquid water saturation at breakthrough reveals that the porosity is not a crucial factor for the limiting current density. An algorithm for condensation is included into the model, which shows that condensing water is redirecting the water path in the GDL, leading to an improved oxygen diffusion by a decreased breakthrough pressure and changed saturation distribution at breakthrough.

  5. 双硫腙修饰光极测定汞(Ⅱ)的研究%Determintation of Mercury( Ⅱ )Ion Using a New Bulk Optode Membrane Based on Dithizone

    Institute of Scientific and Technical Information of China (English)

    吕鉴泉; 夏利君; 邹欣平; 何锡文

    2002-01-01

    以双硫腙为探针构造了PVC膜修饰光极,就该光极的识别机理,酸度、响应时间、选择性等对光度测定的影响和光极再生方法进行了探讨,建立了一种新型的Hg2+离子选择性光极测定方法.结果表明,该修饰光极在pH4.5的缓冲溶液中对汞离子有灵敏的响应,测量范围0~10-5mol l-1,检测限达3.5×10-7moll-1,可应用于生活废水中汞离子的测定.%An ionic selective bulk optode for Hg2+ based on a lipophilized metal ion-chelating reagent [dithizone] dissolved in an o-NPOE plasticized PVC membrane has been developed. In the measuring range of from 0 to 10-5mol @ L-1 Hg2+ at pH4.5,the absorbance response shows a good correlation with the theoretically derived formulae. The limit of detection is 3.5 × 10-7mol @ L-1.The characteristic of the optode towards Hg2+ in B-R pH buffer solution ,such as response time ,reproducibility,lifetime ,selectivity and regenerating method,is investigated. The optode is applied for the detection of Hg2+ in tap water.

  6. Ion-transfer voltammetric determination of the beta-blocker propranolol in a physiological matrix at silicon membrane-based liquid|liquid microinterface arrays.

    Science.gov (United States)

    Collins, Courtney J; Arrigan, Damien W M

    2009-03-15

    In this work, the ion-transfer voltammetric detection of the protonated beta-blocker propranolol in artificial saliva is presented. Cyclic voltammetry, differential pulse voltammetry, and differential pulse stripping voltammetry (DPSV) were employed in the detection of the cationic drug based on ion-transfer voltammetry across arrays of microinterfaces between artificial saliva and an organogel phase. It was found that the artificial saliva matrix decreased the available potential window for ion-transfer voltammetry at this liquid|liquid interface but transfer of protonated propranolol was still achieved. The DPSV method employed a preconditioning step as well as a preconcentration step followed by analytical signal generation based on the back-transfer of the drug across the array of microinterfaces. The DPSV peak current response was linear with drug concentration in the artificial saliva matrix over the concentration range of 0.05-1 microM (i(p) = -8.13 (nA microM(-1))(concentration) + 0.07 (nA), R = 0.9929, n = 7), and the calculated detection limit (3s(b)) was 0.02 microM. These results demonstrate that DPSV at arrays of liquid|liquid microinterfaces is a viable analytical approach for pharmaceutical determinations in biomimetic matrixes.

  7. Separation of Eu(Ⅲ) with supported dispersion liquid membrane system containing D2EHPA as carrier and HNO3 solution as stripping solution

    Institute of Scientific and Technical Information of China (English)

    PEI Liang; WANG Liming; YU Guoqiang

    2011-01-01

    The Eu(Ⅲ) separation in supported dispersion liquid membrane (SDLM), with polyvinylidene fluoride membrane (PVDF) as the support and dispersion solution containing HNO3 solution as the stripping solution and Di(2-ethylhexyl) phosphoric acid (D2EHPA) dissolved in kerosene as the membrane solution, was studied. The effects of pH value, initial concentration of Eu(Ⅲ) and different ionic strengths in the feed phase, volume ratio of membrane solution and stripping solution, concentration of H NO3 solution, concentration of carrier, different stripping agents in the dispersion phase on the separation of Eu(Ⅲ) were also investigated, respectively. As a result, the optimum separation conditions of Eu(Ⅲ) were obtained as the concentration of HNO3 solution was 4.00 mol/L, concentration of D2EHPA was 0.160 mol/L, and volume ratio of membrane solution to stripping solution was 30:30 in the dispersion phase, and pH value was 5.00 in the feed phase. Ionic strength had no obvious effect on the separation of Eu(Ⅲ). Under the optimum conditions studied, when initial concentration of Eu(Ⅲ) was 1.00× 10 4 mol/L, the separation rate of Eu(Ⅲ) was up to 94.2% during the separation period of 35 min. The kinetic equation was developed in terms of the law of mass diffusion and the theory of interface chemistry. The results were in good agreement with the literature data.

  8. Photocatalytic degradation of methyl orange, methylene blue and rhodamine B with AgCl nanocatalyst synthesised from its bulk material in the ionic liquid [P6 6 6 14]Cl.

    Science.gov (United States)

    Rodríguez-Cabo, Borja; Rodríguez-Palmeiro, Iago; Corchero, Raquel; Rodil, Rosario; Rodil, Eva; Arce, Alberto; Soto, Ana

    2017-01-01

    The photocatalytic degradation of wastewater containing three industrial dyes belonging to different families, methyl orange (MO), methylene blue (MB) and Rhodamine B (RhB), was studied under UV-Vis irradiation using synthesised silver chloride nanoparticles. The nanocatalyst was prepared by a dissolution/reprecipitation method starting from the bulk powder and the ionic liquid trihexyl(tetradecyl)phosphonium chloride, [P6 6 6 14]Cl, without addition of other solvents. The obtained catalyst was characterised by UV-Vis absorbance, X-ray powder diffraction, transmission electron microscopy and scanning electron microscopy. The decolourisation of the samples was studied by UV-Vis absorbance at the corresponding wavelength. Starting from 10 ppm dye solutions and 1 g L(-1) of the synthesised AgCl nanoparticles, degradation efficiencies of 98.4% for MO, 98.6% for MB and 99.9% for RhB, were achieved in 1 h. The degradation mechanisms for the different dyes were studied. Comparison with other frequently used nanocatalysts, namely P-25 Degussa, TiO2 anatase, Ag and ZnO, highlights the strong catalytic activity of AgCl nanoparticles. Under the same experimental conditions, these nanoparticles led to higher (more than 10%) and faster degradations.

  9. Novel ceramic-polymer composite membranes for the separation of hazardous liquid waste. 1998 annual progress report

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, Y.

    1998-06-01

    'This report summarizes the work progress over the last 1.75 years of a 3 year project. The objectives of the project have been to develop a new class of ceramic-supported polymeric membranes that could be tailored-designed for a wide-range of applications in remediation and pollution prevention. To date, a new class of chemically-modified ceramic membranes was developed for the treatment of oil-in-water emulsions and for the pervaporation removal of volatile organics from aqueous systems. These new ceramic-supported polymer (CSP) membranes are fabricated by modifying the pore surface of a ceramic membrane support by a graft polymerization process (Chaimberg and Cohen, 1994). The graft polymerization process consists of activating the membrane surface with alkoxy vinyl silanes onto which vinyl monomers are added via free-radical graft polymerization resulting in a thin surface layer of terminally anchored polymer chains. Reaction conditions are selected based on knowledge of the graft polymerization kinetics for the specific polymer/substrate system. The resultant ceramic-supported polymer (CSP) membrane is a composite structure in which mechanical strength is provided by the ceramic support and the selectivity is determined by the covalently bonded polymer brush layer. Thus, one of the unique attributes of the CSP membrane is that it can be used in environments where the polymer layer is swollen (or even completely miscible) in the mixture to be separated (Castro et al., 1993). It is important to note that the above modification process is carried out under mild conditions (e.g., temperature of about 70 C) and is well suited for large scale commercial application. In a series of studies, the applicability of a polyvinylpyrrolidone CSP membrane was demonstrated for the treatment of oil-in-water emulsion under a variety of flow conditions (Castro et al.,1996). Improved membrane performance was achieved due to minimization of surface adsorption of the oil

  10. TREATMENT OF GLYPHOSATE WASTEWATER BY EMULSION LIQUID MEMBRANE SYSTEM%乳状液膜法治理草甘膦废水

    Institute of Scientific and Technical Information of China (English)

    胡筱敏; 周宁; 欧云川; 李鹏; 宇秉勇

    2012-01-01

    采用液膜分离技术从草甘膦生产废水中回收可利用资源草甘膦,并通过实际工业废水进行验证。主要考察了外水相pH值、乳水比及内水相浓度对草甘膦去除的影响。试验结果表明:以航空煤油为溶剂,3%表面活性剂(质量分数),4%载体(体积分数),10%NaOH内水相,油内比Roi为2:1乳状液膜体系,处理初始浓度为1%的草甘膦工业废水,在pH值为2,乳水比Rew为1:5的传质条件下,草甘膦去除率可达85%以上。%Liquid membrane technique is a modern separation technique in recent year that has efficient, speedy and simple characteristics. This paper elaborates on treatment of glyphosate wastewater with emulsion liquid membrane and found appropriate conditions by experimentation. When it deal with glyphosate wastewater, glyphosate can be recovery. The optimum membrane composition and technique on extracting of glyphosate wastewater were studied. The effect on removal rate of glyphosate of the external pH concentration, the ratio of emulsion and water, the internal concentration was examined. The experimental results show that when 10% NaOH (mass fration) as internal aqueous phase; pH of external aqueous phase was 2; Roi=2:1 ; Rew = 1: 5, the removal rate of 1% glyphosate was higher than 85%.

  11. 乳状液膜包酶制备6-APA的研究%Preparation of 6-APA by Enzymatic Bioconversion in an Emulsion Liquid Membrane Reactor

    Institute of Scientific and Technical Information of China (English)

    陆强; 胡鸣; 熊丹柳; 邓修

    2001-01-01

    Production of 6-aminopenicillanic acid (6-APA) by hydrolysis using penicillin acylase (PA) was studied as a model of an enzymatic emulsion liquid membrane (ELM) process. The loss of PA activity was examined for various membrane compositions (organic solvent, surfactant, carrier). The effects of some experimental variables on the stability of emulsion were investigated. It was found that the choice of organic solvent greatly affected the stability of the emulsion. Increasing the concentration of the carrier in the membrane phase increases the transfer rate of substrate and products but also has a destabilizing effect on the emulsion. The recovery of 6-APA obtained by a di-carrier system (N263-N1923) was much higher than those when either of the dj-carriers was used separately. The whole process was controlled both by the enzymatic reaction rate and by the transfer rate of the substrate and the products, however, the ratio of them could be changed by varying the composition of the system. For an optimum condition, it was obtained that the recovery ratio of 6-APA was over 80% and the conversion of benzyl penicillin (PG) was up to 90% in the external phase after 30 minutes. Meanwhile, the breakage percentage of the emulsion was less than 2%.``

  12. Engineering Development of Ceramic Membrane Reactor System for Converting Natural Gas to Hydrogen and Synthesis Gas for Liquid Transportation Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Air Products and Chemicals

    2008-09-30

    An Air Products-led team successfully developed ITM Syngas technology from the concept stage to a stage where a small-scale engineering prototype was about to be built. This technology produces syngas, a gas containing carbon monoxide and hydrogen, by reacting feed gas, primarily methane and steam, with oxygen that is supplied through an ion transport membrane. An ion transport membrane operates at high temperature and oxygen ions are transported through the dense membrane's crystal lattice when an oxygen partial pressure driving force is applied. This development effort solved many significant technical challenges and successfully scaled-up key aspects of the technology to prototype scale. Throughout the project life, the technology showed significant economic benefits over conventional technologies. While there are still on-going technical challenges to overcome, the progress made under the DOE-funded development project proved that the technology was viable and continued development post the DOE agreement would be warranted.

  13. Liquid—liquid interface-mediated Au—ZnO composite membrane using ‘thiol-ene’ click chemistry

    Science.gov (United States)

    Ali, Mohammed; Ghosh, Sujit Kumar

    2015-07-01

    A nanoparticle-decorated composite membrane has been devised at the water/CCl4 interface based on the self-assembly of ligand-stabilized gold and zinc oxide nanoparticles, exploiting the ‘thiol-ene’ click chemistry between the thiol groups of 11-mercaptoundecanoic acid-stabilized ZnO nanoparticles and the ene functionality of cinnamic acid attached to gold nanoparticles. The interfacial assembly of ultrasmall particles leads to a multilayer film that exhibits charge-dependent permeability of amino acid molecules across the membrane.

  14. CO2/N2 separation using supported ionic liquid membranes with green and cost-effective [Choline][Pro]/PEG200 mixtures

    Institute of Scientific and Technical Information of China (English)

    Tengteng Fan; Wenlong Xie; Xiaoyan Ji; Chang Liu; Xin Feng; Xiaohua Lu

    2016-01-01

    The high price and toxicity of ionic liquids (ILs) have limited the design and application of supported ionic liquid membranes (SILMs) for CO2 separation in both academic and industrial fields. In this work, [Choline][Pro]/poly-ethylene glycol 200 (PEG200) mixtures were selected to prepare novel SILMs because of their green and cost-effective characterization, and the CO2/N2 separation with the prepared SILMs was investigated experimental y at temperatures from 308.15 to 343.15 K. The temperature effect on the permeability, solubility and diffusivity of CO2 was modeled with the Arrhenius equation. A competitive performance of the prepared SILMs was ob-served with high CO2 permeability ranged in 343.3-1798.6 barrer and high CO2/N2 selectivity from 7.9 to 34.8. It was also found that the CO2 permeability increased 3 times by decreasing the viscosity of liquids from 370 to 38 mPa·s. In addition, the inherent mechanism behind the significant permeability enhancement was revealed based on the diffusion-reaction theory, i.e. with the addition of PEG200, the overall resistance was substantial y decreased and the SILMs process was switched from diffusion-control to reaction-control.

  15. Removal of cesium from nuclear liquid waste using hybrid organic-inorganic membranes grafted by immobilized calixarenes; Synthese et caracterisation de membranes hybrides organo-minerales contenant des calixarenes. Application au traitement des effluents radioactifs

    Energy Technology Data Exchange (ETDEWEB)

    Duhart, A

    1998-07-01

    The aim of the Actinex program is to reduce massively the noxiousness of the vitrified wastes mainly due to actinides and other long-lived fission products such as {sup 129}I, {sup 99}Tc or {sup 135}Cs. Specific treatment means applicable to the industrial processes of spent fuel reprocessing have to be defined. The selective extraction of these radioelements for their transmutation or packaging in specific matrices is one of the research theme of this program. Different studies allowing the extraction of radioelements such as cesium, americium and plutonium by preferential diffusional transport through a supported liquid membrane of complexes (formed between a selective transport compound and the radioelements) are at the present time carried out in the ETPL (Effluents Treatment Processes Laboratory). Calix-4-arenes mono/bis-crown-6 are used as selective transport compounds. Meanwhile the possible losses of the selective transport compound by dissolution in the aqueous phases have oriented our researches towards a solid material in which the selective transport compound is chemically bound or trapped in the matrix. The transport compound is a calixarene, dissymmetrical and double grafted. It has been specifically synthesized for this study. It allows both to complex the cesium and to chemically bind a hetero-poly-siloxane. These monomers have poly-condensable groups which lead by sol-gel process to the formation of a three-dimensional bonds lattice. The matrix, thus obtained, can be supported either on a mineral material or on a porous organic material. Pre-polymers and the deposited layers have been characterized and correlations between the materials preparation and their properties, applied to cesium extraction, have been established. Experiments of cesium transfer through the solid membrane containing between 2 to 40% of selective transport compound, located between 2 compartments containing upstream, an acidic solution with strong salinity doped with Cs 137

  16. Membrane damage and active but nonculturable state in liquid cultures of Escherichia coli treated with an atmospheric pressure plasma jet.

    Science.gov (United States)

    Dolezalova, Eva; Lukes, Petr

    2015-06-01

    Electrical discharge plasmas can efficiently inactivate various microorganisms. Inactivation mechanisms caused by plasma, however, are not fully understood because of the complexity of both the plasma and biological systems. We investigated plasma-induced inactivation of Escherichia coli in water and mechanisms by which plasma affects bacterial cell membrane integrity. Atmospheric pressure argon plasma jet generated at ambient air in direct contact with bacterial suspension was used as a plasma source. We determined significantly lower counts of E. coli after treatment by plasma when they were assayed using a conventional cultivation technique than using a fluorescence-based LIVE/DEAD staining method, which indicated that bacteria may have entered the viable-but-nonculturable state (VBNC). We did not achieve resuscitation of these non-culturable cells, however, we detected their metabolic activity through the analysis of cellular mRNA, which suggests that cells may have been rather in the active-but-nonculturable state (ABNC). We hypothesize that peroxidation of cell membrane lipids by the reactive species produced by plasma was an important pathway of bacterial inactivation. Amount of malondialdehyde and membrane permeability of E. coli to propidium iodide increased with increasing bacterial inactivation by plasma. Membrane damage was also demonstrated by detection of free DNA in plasma-treated water.

  17. Liquid pearls

    CERN Document Server

    Bremond, Nicolas; Bibette, Jérôme

    2010-01-01

    This fluid dynamics video reports how to form liquid core capsules having a thin hydrogel elastic membrane named liquid pearls. These fish-egg like structures are initially made of a millimetric liquid drop, aqueous or not, coated with an aqueous liquid film containing sodium alginate that gels once the double drop enters a calcium chloride bath. The creation of such pearls with micrometer thick membrane requires to suppress mixing until gelling takes place. Here, we show that superimposing a two dimensional surfactant precipitation at the interface confers a transient rigidity that can damp the shear induced instability at impact. Based on this, pearls containing almost any type of liquids can be created. The video focuses on the dynamics of the entry of the compound drop into the gelling bath.

  18. STED microscopy detects and quantifies liquid phase separation in lipid membranes using a new far-red emitting fluorescent phosphoglycerolipid analogue.

    Science.gov (United States)

    Honigmann, Alf; Mueller, Veronika; Hell, Stefan W; Eggeling, Christian

    2013-01-01

    We have developed a bright, photostable, and far-red emitting fluorescent phosphoglycerolipid analogue to probe diffusion characteristics of lipids in membranes. The lipid analogue consists of a saturated (C18) phosphoethanolamine and a hydrophilic far-red emitting fluorescent dye (KK114) that is tethered to the head group by a long polyethylenglycol linker. In contrast to reported far-red emitting fluorescent lipid analogues, this one partitions predominantly into liquid ordered domains of phase-separated ternary bilayers. We performed fluorescence correlation spectroscopy with a super-resolution STED microscope (STED-FCS) to measure the lateral diffusion of the new lipid analogue in the liquid ordered (Lo) and disordered (Ld) phase. On a mica support, we observed micrometer large phases and found that the lipid analogue diffuses freely on all tested spatial scales (40-250 nm) in both the Ld and Lo phase with diffusion coefficients of 1.8 microm2 s(-1) and 0.7 microm2 s(-1) respectively. This indicates that the tight molecular packing of the Lo phase mainly slows down the diffusion rather than causing anomalous sub-diffusion. The same ternary mixture deposited on acid-cleaned glass forms Lo nanodomains of analogue into the nano-domains, where diffusion is slowed down. Our results suggest that STED-FCS in combination with a Lo-partitioning fluorescent lipid analogue can directly probe the presence of Lo nano-domains, which in the future should allow the study of potential lipid rafts in live-cell membranes.

  19. Treatment of Semi-coke Production Wastewater by Emulsion Liquid Membrane Process%乳状液膜法处理煤制兰炭废水

    Institute of Scientific and Technical Information of China (English)

    刘涛; 程迪; 李鹏

    2013-01-01

    The semi-coke production wastewater was treated by emulsion liquid membrane method using tributyl phosphate (TBP) as carrier,kerosene as membrane solvent,and NaOH solution as aqueous phase.The experimental results show that when the TBP volume fraction is 4%,the surfactant mass fraction is 4%,the mass concentration of NaOH in the internal phase is 12%,the volume ratio of oil to internal phase is 3 ∶ 2,the volume ratio of emulsion liquid to wastewater is 1 ∶ 5 and the extraction time is 15 min,the removal rats of phenols (calculated in phenol) and COD are above 85% and 83% respectively.%以磷酸三丁酯(TBP)为载体、煤油为膜溶剂、NaOH水溶液为内水相,采用乳状液膜法处理兰炭废水.实验结果表明:当TBP体积分数为4%、表面活性剂质量分数为4%、内水相NaOH质量分数为12%、油内比(乳状液的油相与内水相的体积比)为3∶2、乳水比为1∶5、萃取时间为15 min时,废水中的酚类(以苯酚计)去除率达到85%以上,COD去除率达83%以上.

  20. Analysis of liquid water formation in polymer electrolyte membrane (PEM) fuel cell flow fields with a dry cathode supply

    Science.gov (United States)

    Gößling, Sönke; Klages, Merle; Haußmann, Jan; Beckhaus, Peter; Messerschmidt, Matthias; Arlt, Tobias; Kardjilov, Nikolay; Manke, Ingo; Scholta, Joachim; Heinzel, Angelika

    2016-02-01

    PEM fuel cells can be operated within a wide range of different operating conditions. In this paper, the special case of operating a PEM fuel cell with a dry cathode supply and without external humidification of the cathode, is considered. A deeper understanding of the water management in the cells is essential for choosing the optimal operation strategy for a specific system. In this study a theoretical model is presented which aims to predict the location in the flow field at which liquid water forms at the cathode. It is validated with neutron images of a PEM fuel cell visualizing the locations at which liquid water forms in the fuel cell flow field channels. It is shown that the inclusion of the GDL diffusion resistance in the model is essential to describe the liquid water formation process inside the fuel cell. Good agreement of model predictions and measurement results has been achieved. While the model has been developed and validated especially for the operation with a dry cathode supply, the model is also applicable to fuel cells with a humidified cathode stream.

  1. EGFR/cell membrane chromatography-online-high performance liquid chromatography/mass spectrometry method for screening EGFR antagonists from Radix Angelicae Pubescentis

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The intracellular kinase domains of the epidermal growth factor receptor(EGFR) in some tumor cells are significant targets for drug discovery.We have developed a new EGFR cell membrane chromatography(EGFR/CMC)-online-high performance liquid chromatography/mass spectrometry(HPLC/MS) method for screening anti-EGFR antagonists from medicinal herbs such as Radix Angelicae Pubescentis.In this study,the HEK293 EGFR cells with high expression of EGFR were used to prepare cell membrane stationary phase(CMSP) in the EGFR/CMC model.The retention fractions on the EGFR/CMC model were directly analyzed by combining a 10 port columns switcher with a HPLC/MS system online.As a result,osthole from Radix Angelicae Pubescentis was found to be the active component acting on EGFR like dasatinib as the control drug.There was a good relationship between their inhibiting effects on EGFR secretion and HEK293 EGFR cell growth in vitro.This new EGFR/CMC-online-HPLC/MS method can be applied for screening anti-EGFR antagonists from TCMs,for instance,Radix Angelicae Pubescentis.It will be a useful method for drug discovery with natural medicinal herbs as a leading compound resource.

  2. Quantification of lipopolysaccharides in outer membrane vesicle vaccines against meningococcal disease. High-performance liquid chromatographic determination of the constituent 3-hydroxy-lauric acid.

    Science.gov (United States)

    Lyngby, Janne; Olsen, Linda H; Eidem, Tove; Lundanes, Elsa; Jantzen, Erik

    2002-03-01

    A high-performance liquid chromatographic (HPLC) assay for quantification of lipopolysaccharides (LPSs, endotoxins) in outer membrane vesicle vaccines against meningococcal disease has been developed. The LPS constituent, 3-hydroxy-lauric acid, served as marker substance for the quantification. LPS from the vaccine was precipitated by ethanol and the fatty acid constituents, including 3-hydroxy-lauric acid, were released by acidic hydrolysis, collected and purified by solid phase extraction on C18 disc-cartridges and converted into phenacyl esters for UV detection at 240 nm. Quantification of the derivatized 3-hydroxy-lauric acid was achieved by HPLC using a Brownlee RP-18 reversed phase column with acetonitrile/water (68:32, v/v) as mobile phase. The method was found to be linear over the range 3-49 microg LPS/ml with a sensitivity of 1.6 (microg/ml)(-1). The repeatability (within-day precision) of the method at three levels (3-49 microg LPS/ml) was 6-14% relative standard deviation and the intermediate (between-day) precision was 7% relative standard deviation (at level 15 microg LPS/ml). The method has been successfully used in the quality control of a meningococcal B outer membrane vesicle vaccine, containing 4-8% LPS relative to protein (w/w), in our laboratory for three years.

  3. Liquid-phase non-thermal plasma-prepared N-doped TiO(2) for azo dye degradation with the catalyst separation system by ceramic membranes.

    Science.gov (United States)

    Cheng, Hsu-Hui; Chen, Shiao-Shing; Cheng, Yi-Wen; Tseng, Wei-Lun; Wang, Yi-Hui

    2010-01-01

    This study strived to improve the photocatalytic activity by using liquid-phase non-thermal plasma (LPNTP) technology for preparing N-doping TiO(2) as well as to separate/recover the N-dope TiO(2) particles by using ceramic ultrafiltration membrane process. The yellow color N-doped TiO(2) photocatalysts, obtained through the LPNTP process, were characterized with UV-Vis spectroscopy, X-ray diffraction (XRD), and electron spectroscopy for chemical analysis (ESCA). The UV-Vis spectrum of N-doped TiO(2) showed that the absorption band was shifted to 439 nm and the band gap was reduced to 2.82 eV. The structure analysis of XRD spectra showed that the peak positions and the crystal structure remained unchanged as anatase after plasma-treating at 13.5 W for 40 min. The photocatalytic activity of N-doped TiO(2) was evaluated by azo dyes under visible light, and 63% of them was degraded after 16 hours in a continuous-flow photocatalytic system. For membrane separation/recover system, the recovery efficiency reached 99.5% after the ultrafiltration had been carried out for 90 min, and the result indicated that the photocatalyst was able to be separated/recovered completely.

  4. Cr(VI) transport via a supported ionic liquid membrane containing CYPHOS IL101 as carrier: system analysis and optimization through experimental design strategies.

    Science.gov (United States)

    Rodríguez de San Miguel, Eduardo; Vital, Xóchitl; de Gyves, Josefina

    2014-05-30

    Chromium(VI) transport through a supported liquid membrane (SLM) system containing the commercial ionic liquid CYPHOS IL101 as carrier was studied. A reducing stripping phase was used as a mean to increase recovery and to simultaneously transform Cr(VI) into a less toxic residue for disposal or reuse. General functions which describe the time-depending evolution of the metal fractions in the cell compartments were defined and used in data evaluation. An experimental design strategy, using factorial and central-composite design matrices, was applied to assess the influence of the extractant, NaOH and citrate concentrations in the different phases, while a desirability function scheme allowed the synchronized optimization of depletion and recovery of the analyte. The mechanism for chromium permeation was analyzed and discussed to contribute to the understanding of the transfer process. The influence of metal concentration was evaluated as well. The presence of different interfering ions (Ca(2+), Al(3+), NO3(-), SO4(2-), and Cl(-)) at several Cr(VI): interfering ion ratios was studied through the use of a Plackett and Burman experimental design matrix. Under optimized conditions 90% of recovery was obtained from a feed solution containing 7mgL(-1) of Cr(VI) in 0.01moldm(-3) HCl medium after 5h of pertraction.

  5. Electrokinetic extraction on artificial liquid membranes of amphetamine-type stimulants from urine samples followed by high performance liquid chromatography analysis.

    Science.gov (United States)

    Seidi, Shahram; Yamini, Yadollah; Baheri, Tahmineh; Feizbakhsh, Rouhollah

    2011-07-01

    Electromembrane extraction (EME) coupled with high performance liquid chromatography and ultraviolet detection was developed for determination of amphetamine-type stimulants in human urine samples. Amphetamines migrated from 3 mL of different human urine matrices, through a thin layer of 2-nitrophenyl octyl ether (NPOE) containing 15% tris-(2-ethylhexyl) phosphate (TEHP) immobilized in the pores of a porous hollow fiber, and into a 15 μL acidic aqueous acceptor solution present inside the lumen of the fiber. Equilibrium extraction conditions were obtained after 7 min of operation. Experimental design and response surface methodology (RSM) were used for optimization of EME parameters. Under optimal conditions, amphetamines were effectively extracted with recoveries in the range of 54-70%, which corresponded to preconcentration factors in the range of 108-140. The calibration curves were investigated in the range of 0-7 μg mL(-1) and good linearity was achieved with a coefficient of estimation better than 0.991. Detection limits and inter-day precision (n=3) were less than 0.01 μg mL(-1) and 11.2%, respectively.

  6. PURIFICATION OF THE INTEGRAL MEMBRANE-GLYCOPROTEINS-D OF HERPES-SIMPLEX VIRUS TYPE-1 AND TYPE-2, PRODUCED IN THE RECOMBINANT BACULOVIRUS EXPRESSION SYSTEM, BY ION-EXCHANGE HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

    NARCIS (Netherlands)

    DAMHOF, RA; FEIJLBRIEF, M; WELLINGWESTER, S; WELLING, GW

    1994-01-01

    Selective elution of Sendai virus integral membrane proteins by ion-exchange high-performance liquid chromatography (HPIEC) using different detergent concentrations was reported before [S. Welling-Wester, M. Feijlbrief, D.G.A.M. Koedijk, M.A. Braaksma, B.R.K. Douma and G.W. Welling, J. Chromatogr.,

  7. EFFECT OF DIFFERENT AMOUNTS OF THE NONIONIC DETERGENTS C-10E(5) AND C-12E(5) PRESENT IN ELUENTS FOR ION-EXCHANGE HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY OF INTEGRAL MEMBRANE-PROTEINS OF SENDAI VIRUS

    NARCIS (Netherlands)

    WELLINGWESTER, S; FEIJLBRIEF, M; KOEDIJK, DGAM; BRAAKSMA, MA; DOUMA, BRK; WELLING, GW

    1993-01-01

    Non-ionic detergents (0.03-0.5%) are used as additives to the eluents when integral membrane proteins are subjected to ion-exchange high-performance liquid chromatography (HPIEC). It is not known whether this concentration should bear some relation to the critical micelle concentration (CMC) of a de

  8. Hollow Fiber Supported Liquid Membrane Extraction Combined with HPLC-UV for Simultaneous Preconcentration and Determination of Urinary Hippuric Acid and Mandelic Acid

    Directory of Open Access Journals (Sweden)

    Abdulrahman Bahrami

    2017-02-01

    Full Text Available This work describes a new extraction method with hollow-fiber liquid-phase microextraction based on facilitated pH gradient transport for analyzing hippuric acid and mandelic acid in aqueous samples. The factors affecting the metabolites extraction were optimized as follows: the volume of sample solution was 10 mL with pH 2 containing 0.5 mol·L−1 sodium chloride, liquid membrane containing 1-octanol with 20% (w/v tributyl phosphate as the carrier, the time of extraction was 150 min, and stirring rate was 500 rpm. The organic phase immobilized in the pores of a hollow fiber was back-extracted into 24 µL of a solution containing sodium carbonate with pH 11, which was placed inside the lumen of the fiber. Under optimized conditions, the high enrichment factors of 172 and 195 folds, detection limit of 0.007 and 0.009 µg·mL−1 were obtained. The relative standard deviation (RSD (% values for intra- and inter-day precisions were calculated at 2.5%–8.2% and 4.1%–10.7%, respectively. The proposed method was successfully applied to the analysis of these metabolites in real urine samples. The results indicated that hollow-fiber liquid-phase microextraction (HF-LPME based on facilitated pH gradient transport can be used as a sensitive and effective method for the determination of mandelic acid and hippuric acid in urine specimens.

  9. Highly Selective Liquid Membrane Sensor Based on 1,3,5-Triphenylpyrylium Perchlorate for Quick Monitoring of Sulfate Ions

    Energy Technology Data Exchange (ETDEWEB)

    Ganjali, Mohammad Reza; Ghorbani, Maryam; Daftari, Azadeh; Norouzi, Parviz; Pirelahi, Hooshang; Dargahani, Hossein Daryanavard [Tehran University, Tehran (Iran, Islamic Republic of)

    2004-02-15

    A highly selective membrane electrode based on 1,3,5-triphenylpyrylium perchlorate (TPPP) is presented. The proposed electrode shows very good selectivity for sulfate ions over a wide variety of common inorganic and organic anions. The sensor displays a nice Nernstian slope of -29.7 mV per decade. The working concentration ranges of the electrode is 1.0 x 10{sup -1} . 6.3 x 10{sup -6} M with a detection limit of 4.0 x 10{sup -6} M (480 ng per mL). The response time of the sensor in whole concentration ranges is very short (< 6 s). The response of the sensor is independent on the pH range of 2.5-9.5. The best performance was obtained with a membrane composition of 32% PVC, 59% benzyl acetate, 5% TPPP and 4% hexadecyltrimethylammonium bromide. It was successfully used as an indicator electrode for titration of sulfate ions with barium ions. The electrode was also applied for determination of salbutamol sulfate and paramomycine sulfate

  10. Membrane distillation for milk concentration

    NARCIS (Netherlands)

    Moejes, S.N.; Romero Guzman, Maria; Hanemaaijer, J.H.; Barrera, K.H.; Feenstra, L.; Boxtel, van A.J.B.

    2015-01-01

    Membrane distillation is an emerging technology to concentrate liquid products while producing high quality water as permeate. Application for desalination has been studied extensively the past years, but membrane distillation has also potential to produce concentrated food products like concentrate

  11. 支撑型离子液体膜用于捕集酸性气体研究%Application of Supported Ionic Liquid Membranes in Capturing Acid Gases

    Institute of Scientific and Technical Information of China (English)

    马玉玲; 徐琴琴; 徐刚; 银建中

    2012-01-01

    Supported ionic liquid membranes (SILMs) are widely used for capturing acid gases in recent years because of its higher mass transfer rate and stability. In this paper, preparation methods of supported ionic liquid membranes were introduced; the capture mechanism was analyzed; some factors to affect permeability and stability of the supported ionic liquid membranes were discussed in detail, such as structure of ionic liquid, properties of supported materials, operation temperature and trans-membrane pressure, water vapor in flue gas and so on; some methods to improve the stability were introduced. On this basis, some problems during application of SILMs in capturing the acid gases were put forward as well as its industrialization prospect.%烟道气中酸性气体的捕集非常重要.近年来,支撑型离子液体膜(Supported ionic liquid membranes,SILMs)因传质速率高、稳定性好等特点而广泛应用于酸性气体的捕集研究.主要综述了利用离子液体作为膜液相来制备支撑液膜的方法,分析了捕集机理,讨论了离子液体阴阳离子结构、支撑体材料性能、原料气中水蒸汽、操作温度及跨膜压差等因素对支撑型离子液体膜渗透性及稳定性的影响,叙述了目前提高稳定性的一些方法,并在此基础上提出了支撑型离子液体膜用于酸性气体捕集需要解决的问题和工业化前景.

  12. Polymer membrane based electrolytic cell and process for the direct generation of hydrogen peroxide in liquid streams

    Science.gov (United States)

    White, James H. (Inventor); Schwartz, Michael (Inventor); Sammells, Anthony F. (Inventor)

    1997-01-01

    An electrolytic cell for generating hydrogen peroxide is provided including a cathode containing a catalyst for the reduction of oxygen, and an anode containing a catalyst for the oxidation of water. A polymer membrane, semipermeable to either protons or hydroxide ions is also included and has a first face interfacing to the cathode and a second face interfacing to the anode so that when a stream of water containing dissolved oxygen or oxygen bubbles is passed over the cathode and a stream of water is passed over the anode, and an electric current is passed between the anode and the cathode, hydrogen peroxide is generated at the cathode and oxygen is generated at the anode.

  13. The impact range for smooth wall–liquid interactions in nanoconfined liquids

    DEFF Research Database (Denmark)

    Ingebrigtsen, Trond; Dyre, J. C.

    2014-01-01

    decade. Inspired by these observations, we present results from molecular dynamics computer simulations of four nanoconfined liquids (the single-component Lennard-Jones liquid, the Kob–Andersen binary Lennard-Jones mixture, an asymmetric dumbbell model, and the Dzugutov liquid) demonstrating also...... a microscopic similarity between bulk and nanoconfined liquids. The results show that the interaction range for the wall–liquid and liquid–liquid interactions of the nanoconfined liquid is identical to that of the bulk liquid if the liquid is “Roskilde simple” in bulk as well as nanoconfinement, i.e., exhibits...

  14. Large area bulk superconductors

    Science.gov (United States)

    Miller, Dean J.; Field, Michael B.

    2002-01-01

    A bulk superconductor having a thickness of not less than about 100 microns is carried by a polycrystalline textured substrate having misorientation angles at the surface thereof not greater than about 15.degree.; the bulk superconductor may have a thickness of not less than about 100 microns and a surface area of not less than about 50 cm.sup.2. The textured substrate may have a thickness not less than about 10 microns and misorientation angles at the surface thereof not greater than about 15.degree.. Also disclosed is a process of manufacturing the bulk superconductor and the polycrystalline biaxially textured substrate material.

  15. Specular and off-specular neutron scattering from solid-supported glycolipid membrane multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Schneck, Emanuel; Tanaka, Motomu [Physikalisch-Chemisches Institut, Universitaet Heidelberg (Germany); Rehfeldt, Florian [Lehrstuhl fuer Biophysik E22, Technische Universitaet Muenchen (Germany); Deme, Bruno [Institut Laue-Langevin, Grenoble (France); Gege, Christian; Schmidt, Richard [Fachbereich Chemie, Universitaet Konstanz (Germany)

    2008-07-01

    Solid-supported glycolipid membrane multilayers, acting as well-defined model systems for the study of saccharide-mediated inter-membrane interactions, were studied by specular and off-specular neutron scattering. Experiments were carried out at controlled temperatures and humidities, as well as under bulk water using a self-developed liquid cell. Force-distance relationships were recorded by measuring at various osmotic pressures. Mechanical properties of the studied membranes (i.e. bending moduli and inter-membrane compression moduli) were extracted by comparing scattering signals to reciprocal space maps simulated in the framework of smectic crystal theory. The results demonstrate that distinct variations in the oligosaccharide headgroup structures of the glycolipid molecules can result in significant changes in bending modulus and inter-membrane interactions.

  16. Novel membrane bioreactor with gas/liquid two-phase flow for high-performance degradation of phenol

    Energy Technology Data Exchange (ETDEWEB)

    Leonard, D.; Mercier-Bonin, M.; Lindley, N.D.; Lafforgue, C. [Inst. National des Sciences Appliquees, Toulouse (France)

    1998-09-01

    The use of a membrane bioreactor with cell retention to achieve high biomass concentrations has been examined for phenol degradation by the bacteria Alcaligenes eutrophus. This process is particularly interesting for toxic substrates as the hydraulic dilution rate and the growth rate are independently controlled. In the case of a transitory excess of phenol, this potentially toxic situation can be overcome by modifying the substrate concentration or the dilute rate without any loss of cells. The injection of a gas phase at the filter inlet increased both the permeate flow rate and the oxygen transfer capacity. This has enabled the cell concentration to reach a maximum value of 60 g L{sup {minus}1} with a hydraulic dilution rate of 0.5 h{sup {minus}1} and a phenol feed concentration of 8 g L{sup {minus}1}. The volumetric productivity of this process corresponds to a phenol degradation rate approaching 100 kg m{sup {minus}3} day{sup {minus}1}. The on-line measurement of the characteristic yellow color of 2-hydroxymuconate semialdehyde, a metabolic intermediate of the phenol degradation pathway, in the permeate provides an interesting basis for process control of phenol supply into the reactor since the color intensity correlates directly to the specific rate of phenol degradation.

  17. How Lipid Membranes Affect Pore Forming Toxin Activity.

    Science.gov (United States)

    Rojko, Nejc; Anderluh, Gregor

    2015-12-15

    Pore forming toxins (PFTs) evolved to permeate the plasma membrane of target cells. This is achieved in a multistep mechanism that usually involves binding of soluble protein monomer to the lipid membrane, oligomerization at the plane of the membrane, and insertion of part of the polypeptide chain across the lipid membrane to form a conductive channel. Introduced pores allow uncontrolled transport of solutes across the membrane, inflicting damage to the target cell. PFTs are usually studied from the perspective of structure-function relationships, often neglecting the important role of the bulk membrane properties on the PFT mechanism of action. In this Account, we discuss how membrane lateral heterogeneity, thickness, and fluidity influence the pore forming process of PFTs. In general, lipid molecules are more accessible for binding in fluid membranes due to steric reasons. When PFT specifically binds ordered domains, it usually recognizes a specific lipid distribution pattern, like sphingomyelin (SM) clusters or SM/cholesterol complexes, and not individual lipid species. Lipid domains were also suggested to act as an additional concentration platform facilitating PFT oligomerization, but this is yet to be shown. The last stage in PFT action is the insertion of the transmembrane segment across the membranes to build the transmembrane pore walls. Conformational changes are a spontaneous process, and sufficient free energy has to be available for efficient membrane penetration. Therefore, fluid bilayers are permeabilized more readily in comparison to highly ordered and thicker liquid ordered lipid phase (Lo). Energetically more costly insertion into the Lo phase can be driven by the hydrophobic mismatch between the thinner liquid disordered phase (Ld) and large protein complexes, which are unable to tilt like single transmembrane segments. In the case of proteolipid pores, membrane properties can directly modulate pore size, stability, and even selectivity. Finally

  18. Incorporation of antimicrobial peptides into membranes: a combined liquid-state NMR and molecular dynamics study of alamethicin in DMPC/DHPC bicelles.

    Science.gov (United States)

    Dittmer, Jens; Thøgersen, Lea; Underhaug, Jarl; Bertelsen, Kresten; Vosegaard, Thomas; Pedersen, Jan M; Schiøtt, Birgit; Tajkhorshid, Emad; Skrydstrup, Troels; Nielsen, Niels Chr

    2009-05-14

    Detailed insight into the interplay between antimicrobial peptides and biological membranes is fundamental to our understanding of the mechanism of bacterial ion channels and the action of these in biological host-defense systems. To explore this interplay, we have studied the incorporation, membrane-bound structure, and conformation of the antimicrobial peptide alamethicin in lipid bilayers using a combination of 1H liquid-state NMR spectroscopy and molecular dynamics (MD) simulations. On the basis of experimental NMR data, we evaluate simple in-plane and transmembrane incorporation models as well as pore formation for alamethicin in DMPC/DHPC (1,2-dimyristoyl-sn-glycero-3-phosphatidylcholine/1,2-dihexanoyl-sn-glycero-3-phosphatidylcholine) bicelles. Peptide-lipid nuclear Overhauser effect (NOE) and paramagnetic relaxation enhancement (PRE) data support a transmembrane configuration of the peptide in the bilayers, but they also reveal that the system cannot be described by a single simple conformational model because there is a very high degree of dynamics and heterogeneity in the three-component system. To explore the origin of this heterogeneity and dynamics, we have compared the NOE and PRE data with MD simulations of an ensemble of alamethicin peptides in a DMPC bilayer. From all-atom MD simulations, the contacts between peptide, lipid, and water protons are quantified over a time interval up to 95 ns. The MD simulations provide a statistical base that reflects our NMR data and even can explain some initially surprising NMR results concerning specific interactions between alamethicin and the lipids.

  19. Functionalized nanoparticles based solid-phase membrane micro-tip extraction and high-performance liquid chromatography analyses of vitamin B complex in human plasma.

    Science.gov (United States)

    Ali, Imran; Kulsum, Umma; Al-Othman, Zeid A; Alwarthan, Abdulrahman; Saleem, Kishwar

    2016-07-01

    Iron nanoparticles were prepared by a green method following functionalization using 1-butyl-3-methylimidazolium bromide. 1-Butyl-3-methylimidazole iron nanoparticles were characterized using FTIR spectroscopy, energy dispersive X-ray fluorescence, X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The nanoparticles were used in solid-phase membrane micro-tip extraction to separate vitamin B complex from plasma before high-performance liquid chromatography. The optimum conditions obtained were sorbent (15 mg), agitation time (30 min), pH (9.0), desorbing solvent [water (5 mL) + methanol (5 mL) + sodium hydroxide (0.1 N) + acetic acid (d = 1.05 kg/L, pH 5.5), desorbing volume (10 mL) and desorption time (30 min). The percentage recoveries of all the eight vitamin B complex were from 60 to 83%. A high-performance liquid chromatography method was developed using a PhE column (250 × 4.6 mm, 5.0 μm) and water/acetonitrile (95:5, v/v; pH 4.0 with 0.1% formic acid) mobile phase. The flow rate was 1.0 mL/min with detection at 270 and 210 nm. The values of the capacity, separation and resolution factor were 0.57-39.47, 1.12-6.00 and 1.84-26.26, respectively. The developed sample preparation and chromatographic methods were fast, selective, inexpensive, economic and reproducible. The developed method can be applied for analyzing these drugs in biological and environmental matrices.

  20. Ion Exchange and Antibiofouling Properties of Poly(ether sulfone) Membranes Prepared by the Surface Immobilization of Brønsted Acidic Ionic Liquids via Double-Click Reactions.

    Science.gov (United States)

    Yi, Zhuan; Liu, Cui-Jing; Zhu, Li-Ping; Xu, You-Yi

    2015-07-28

    Brønsted acidic ionic liquids (BAILs) are unique ionic liquids that display chemical structures similar to zwitterions, and they were typically used as solvents and catalysts. In this work, an imidazole-based BAIL monolayer was fabricated onto poly(ether sulfone) (PES) membranes via surface clicking reactions, and the multifunctionality, including ion exchange and biofouling resistance to proteins and bacteria, was demonstrated, which was believed to be one of few works in which BAIL had been considered to be a novel fouling resistance layer for porous membranes. The successful immobilization of the BAILs onto a membrane surface was confirmed by X-ray photoelectron spectroscopy analysis, contact angle measurement, and ζ potential determination. The results from Raman spectroscopy showed that, as a decisive step prior to zwitterion, the BAIL was deprotonated in aqueous solution, and biofouling resistance to proteins and bacteria was found. However, BAIL displayed ion exchange ability at lower pH, and surface hydrophilicity/hydrophobicity of membranes could be tuned on purpose. Our results have demonstrated that the BAIL grafted onto membranes will not only act as an antibiofouling barrier like zwitterions but also provide a platform for surface chemical tailoring by ion exchange, the property of which will become especially important in acidic solutions where the fouling resistance performances of zwitterions are greatly weakened.

  1. From biological membranes to biomimetic model membranes

    Directory of Open Access Journals (Sweden)

    Eeman, M.

    2010-01-01

    Full Text Available Biological membranes play an essential role in the cellular protection as well as in the control and the transport of nutrients. Many mechanisms such as molecular recognition, enzymatic catalysis, cellular adhesion and membrane fusion take place into the biological membranes. In 1972, Singer et al. provided a membrane model, called fluid mosaic model, in which each leaflet of the bilayer is formed by a homogeneous environment of lipids in a fluid state including globular assembling of proteins and glycoproteins. Since its conception in 1972, many developments were brought to this model in terms of composition and molecular organization. The main development of the fluid mosaic model was made by Simons et al. (1997 and Brown et al. (1997 who suggested that membrane lipids are organized into lateral microdomains (or lipid rafts with a specific composition and a molecular dynamic that are different to the composition and the dynamic of the surrounding liquid crystalline phase. The discovery of a phase separation in the plane of the membrane has induced an explosion in the research efforts related to the biology of cell membranes but also in the development of new technologies for the study of these biological systems. Due to the high complexity of biological membranes and in order to investigate the biological processes that occur on the membrane surface or within the membrane lipid bilayer, a large number of studies are performed using biomimicking model membranes. This paper aims at revisiting the fundamental properties of biological membranes in terms of membrane composition, membrane dynamic and molecular organization, as well as at describing the most common biomimicking models that are frequently used for investigating biological processes such as membrane fusion, membrane trafficking, pore formation as well as membrane interactions at a molecular level.

  2. Technical issues of a high-Tc superconducting bulk magnet

    Science.gov (United States)

    Fujimoto, Hiroyuki

    2000-06-01

    Superconducting magnets made of high-Tc superconductors are promising for industrial applications. It is well known that REBa2Cu3O7-x superconductors prepared by melt processes have a high critical current density, Jc, at 77 K and high magnetic fields. The materials are very promising for high magnetic field applications as a superconducting permanent/bulk magnet with liquid-nitrogen refrigeration. Light rare-earth (LRE) BaCuO bulks, compared with REBaCuO bulks, exhibit a larger Jc in high magnetic fields and a much improved irreversibility field, Hirr, at 77 K. In this study, we discuss technical issues of a high-Tc superconducting bulk magnet, namely the aspects of the melt processing for bulk superconductors, their characteristic superconducting properties and mechanical properties, and trapped field properties of a superconducting bulk magnet. One of the possible applications is a superconducting bulk magnet for the magnetically levitated (Maglev) train in the future.

  3. Microfabricated bulk wave acoustic bandgap device

    Science.gov (United States)

    Olsson, Roy H.; El-Kady, Ihab F.; McCormick, Frederick; Fleming, James G.; Fleming, Carol

    2010-06-08

    A microfabricated bulk wave acoustic bandgap device comprises a periodic two-dimensional array of scatterers embedded within the matrix material membrane, wherein the scatterer material has a density and/or elastic constant that is different than the matrix material and wherein the periodicity of the array causes destructive interference of the acoustic wave within an acoustic bandgap. The membrane can be suspended above a substrate by an air or vacuum gap to provide acoustic isolation from the substrate. The device can be fabricated using microelectromechanical systems (MEMS) technologies. Such microfabricated bulk wave phononic bandgap devices are useful for acoustic isolation in the ultrasonic, VHF, or UHF regime (i.e., frequencies of order 1 MHz to 10 GHz and higher, and lattice constants of order 100 .mu.m or less).

  4. Biomimetic membranes and methods of making biomimetic membranes

    Energy Technology Data Exchange (ETDEWEB)

    Rempe, Susan; Brinker, Jeffrey C.; Rogers, David Michael; Jiang, Ying-Bing; Yang, Shaorong

    2016-11-08

    The present disclosure is directed to biomimetic membranes and methods of manufacturing such membranes that include structural features that mimic the structures of cellular membrane channels and produce membrane designs capable of high selectivity and high permeability or adsorptivity. The membrane structure, material and chemistry can be selected to perform liquid separations, gas separation and capture, ion transport and adsorption for a variety of applications.

  5. Gases, liquids and solids

    CERN Document Server

    Tabor, David

    1969-01-01

    It has been tradional to treat gases, liquids and solids as if they were completely unrelated material. However, this book shows that many of their bulk properties can been explained in terms of intermolecular forces.

  6. Pressure effects on the equilibrium configurations of bilayer lipid membranes

    Science.gov (United States)

    DeVita, Raffaella; Stewart, Iain W.; Leo, Donald J.

    2007-10-01

    Planar bilayer lipid membranes (BLMs) are currently employed to construct many bio-inspired material systems and structures. In order to characterize the pressure effects on the equilibrium configurations of these biological membranes, a novel continuum model is proposed. The BLM is assumed to be a two-layer smectic A liquid crystal. The mean orientation of the amphiphilic molecules comprising the membrane is postulated to be perpendicular to the layers and each layer is idealized as a two-dimensional liquid. Moreover, the BLM is modeled as a simply supported plate undergoing small deformations. It is subjected to a pressure load that acts perpendicularly to the layers. The equilibrium equations and boundary conditions are derived from the bulk elastic energy for smectic A liquid crystals as described by de Gennes and Prost (1993 The Physics of Liquid Crystals 2nd edn (Oxford Science Publications)) by using variational methods. The resulting fourth-order linear partial differential equation is solved by employing cylindrical functions and the series solution is proved to be convergent. The solution is numerically computed for values of the model parameters that are reported in the literature. This paper is dedicated to the memory of our colleagues, Professors Kevin P Granata and Liviu Librescv, who lost their lives during the sensless tragedy on 16 April, 2007 at Virginia Tech.

  7. Nitrocellulose membrane sample holder using for terahertz time domain spectroscopy

    Science.gov (United States)

    Zhao, Xiaojing; Liu, Shangjian; Wang, Cuicui; Zuo, Jian; Zhang, Cunlin

    2016-11-01

    Terahertz (THz) technology has promising applications for the detection and identification of materials because it has a great advantage in measuring material fingerprint spectrum. Terahertz time-domain spectroscopy (THz-TDS) is a key technique that is applied to spectroscopic measurement of materials. However, it is difficult to press a pellet with small mass of sample and a bulking medium such as polyethylene (PE) powder usually need to be added. Characteristic absorption peaks of the solution in liquid cell is hard to be observed due to the interaction between materials and water molecules. Therefore, one method using the hydrophilic nitrocellulose (NC) membrane as a sample holder was applied to detect samples in an aqueous medium by THz-TDS. In this study, the α-lactose samples were mixed with 20 μl of deionized water and then applied directly onto the double-layered NC membrane sample holder. This mixture is located on the gap of two piece of NC membranes. Firstly the NC membranes with different pore sizes were tested in the experiment. And then the α-lactose solutions with different concentrations were measured on the NC with different pore sizes. Consequently, the small mass of samples can be detected and the characteristic absorption peaks become stronger with the increase of NC pore size. Moreover, compared to the traditional pellet-making and liquid cell detection, this membrane method is more convenient and easy to operate.

  8. Liquid/liquid heat exchanger

    Science.gov (United States)

    Miller, C. G.

    1980-01-01

    Conceptual design for heat exchanger, utilizing two immiscible liquids with dissimilar specific gravities in direct contact, is more efficient mechanism of heat transfer than conventional heat exchangers with walls or membranes. Concept could be adapted for collection of heat from solar or geothermal sources.

  9. Preliminary study of superconducting bulk magnets for Maglev

    Science.gov (United States)

    Fujimoto, Hiroyuki; Kamijo, Hiroki

    Recent development shows that melt-processed YBaCuO (Y123) or Rare Earth (RE)123 superconductors have a high Jc at 77 K and high magnetic field, leading to high field application as a superconducting quasi-permanent bulk magnet with the liquid nitrogen refrigeration. One of the promising applications is a superconducting magnet for the magnetically levitated (Maglev) train. We discuss a superconducting bulk magnet for the Maglev train in the aspect of a preliminary design of the bulk magnet and also processing for (L)REBaCuO bulk superconductors and their characteristic superconducting properties.

  10. Water Membrane Evaporator

    Science.gov (United States)

    Ungar, Eugene K.; Almlie, Jay C.

    2010-01-01

    A water membrane evaporator (WME) has been conceived and tested as an alternative to the contamination-sensitive and corrosion-prone evaporators currently used for dissipating heat from space vehicles. The WME consists mainly of the following components: An outer stainless-steel screen that provides structural support for the components mentioned next; Inside and in contact with the stainless-steel screen, a hydrophobic membrane that is permeable to water vapor; Inside and in contact with the hydrophobic membrane, a hydrophilic membrane that transports the liquid feedwater to the inner surface of the hydrophobic membrane; Inside and in contact with the hydrophilic membrane, an annular array of tubes through which flows the spacecraft coolant carrying the heat to be dissipated; and An inner exclusion tube that limits the volume of feedwater in the WME. In operation, a pressurized feedwater reservoir is connected to the volume between the exclusion tube and the coolant tubes. Feedwater fills the volume, saturates the hydrophilic membrane, and is retained by the hydrophobic membrane. The outside of the WME is exposed to space vacuum. Heat from the spacecraft coolant is conducted through the tube walls and the water-saturated hydrophilic membrane to the liquid/vapor interface at the hydrophobic membrane, causing water to evaporate to space. Makeup water flows into the hydrophilic membrane through gaps between the coolant tubes.

  11. Preparation and Characterization of Facilitated Transport Membranes Composed of Chitosan-Styrene and Chitosan-Acrylonitrile Copolymers Modified by Methylimidazolium Based Ionic Liquids for CO₂ Separation from CH₄ and N₂.

    Science.gov (United States)

    Otvagina, Ksenia V; Mochalova, Alla E; Sazanova, Tatyana S; Petukhov, Anton N; Moskvichev, Alexandr A; Vorotyntsev, Andrey V; Afonso, Carlos A M; Vorotyntsev, Ilya V

    2016-06-09

    CO₂ separation was found to be facilitated by transport membranes based on novel chitosan (CS)-poly(styrene) (PS) and chitosan (CS)-poly(acrylonitrile) (PAN) copolymer matrices doped with methylimidazolium based ionic liquids: [bmim][BF₄], [bmim][PF₆], and [bmim][Tf₂N] (IL). CS plays the role of biodegradable film former and selectivity promoter. Copolymers were prepared implementing the latest achievements in radical copolymerization with chosen monomers, which enabled the achievement of outstanding mechanical strength values for the CS-based membranes (75-104 MPa for CS-PAN and 69-75 MPa for CS-PS). Ionic liquid (IL) doping affected the surface and mechanical properties of the membranes as well as the gas separation properties. The highest CO₂ permeability 400 Barrers belongs to CS-b-PS/[bmim][BF₄]. The highest selectivity α (CO₂/N₂) = 15.5 was achieved for CS-b-PAN/[bmim][BF₄]. The operational temperature of the membranes is under 220 °C.

  12. Preparation and Characterization of Facilitated Transport Membranes Composed of Chitosan-Styrene and Chitosan-Acrylonitrile Copolymers Modified by Methylimidazolium Based Ionic Liquids for CO2 Separation from CH4 and N2

    Directory of Open Access Journals (Sweden)

    Ksenia V. Otvagina

    2016-06-01

    Full Text Available CO2 separation was found to be facilitated by transport membranes based on novel chitosan (CS–poly(styrene (PS and chitosan (CS–poly(acrylonitrile (PAN copolymer matrices doped with methylimidazolium based ionic liquids: [bmim][BF4], [bmim][PF6], and [bmim][Tf2N] (IL. CS plays the role of biodegradable film former and selectivity promoter. Copolymers were prepared implementing the latest achievements in radical copolymerization with chosen monomers, which enabled the achievement of outstanding mechanical strength values for the CS-based membranes (75–104 MPa for CS-PAN and 69–75 MPa for CS-PS. Ionic liquid (IL doping affected the surface and mechanical properties of the membranes as well as the gas separation properties. The highest CO2 permeability 400 Barrers belongs to CS-b-PS/[bmim][BF4]. The highest selectivity α (CO2/N2 = 15.5 was achieved for CS-b-PAN/[bmim][BF4]. The operational temperature of the membranes is under 220 °C.

  13. Effect of internal pressure and gas/liquid interface area on the CO mass transfer coefficient using hollow fibre membranes as a high mass transfer gas diffusing system for microbial syngas fermentation.

    Science.gov (United States)

    Yasin, Muhammad; Park, Shinyoung; Jeong, Yeseul; Lee, Eun Yeol; Lee, Jinwon; Chang, In Seop

    2014-10-01

    This study proposed a submerged hollow fibre membrane bioreactor (HFMBR) system capable of achieving high carbon monoxide (CO) mass transfer for applications in microbial synthesis gas conversion systems. Hydrophobic polyvinylidene fluoride (PVDF) membrane fibres were used to fabricate a membrane module, which was used for pressurising CO in water phase. Pressure through the hollow fibre lumen (P) and membrane surface area per unit working volume of the liquid (A(S)/V(L)) were used as controllable parameters to determine gas-liquid volumetric mass transfer coefficient (k(L)a) values. We found a k(L)a of 135.72 h(-1) when P was 93.76 kPa and AS/VL was fixed at 27.5m(-1). A higher k(L)a of 155.16 h(-1) was achieved by increasing AS/VL to 62.5m(-1) at a lower P of 37.23 kPa. Practicality of HFMBR to support microbial growth and organic product formation was assessed by CO/CO2 fermentation using Eubacterium limosum KIST612.

  14. Bulk chemicals from biomass

    NARCIS (Netherlands)

    Haveren, van J.; Scott, E.L.; Sanders, J.P.M.

    2008-01-01

    Given the current robust forces driving sustainable production, and available biomass conversion technologies, biomass-based routes are expected to make a significant impact on the production of bulk chemicals within 10 years, and a huge impact within 20-30 years. In the Port of Rotterdam there is a

  15. Research on Separation of H2 and N2 Mixed Gas with Ionic liquid Membrane%离子液膜法分离H2、N2混合气体研究

    Institute of Scientific and Technical Information of China (English)

    仲惟

    2015-01-01

    Two kinds of ionic liquid, 1-butyl 3-sold four fluoboric acid methyl imidazole salt ([BMIM]BF4) and 1-butyl 3-methyl imidazole six fluoride phosphate ([BMIM] PF6), were selected, and the ion exchange method was used to create two kinds of ionic liquid 1-butyl 3-methyl imidazole formate ([BMIM] HCOO) and 1-butyl 3-methyl imidazole acetate ([BMIM]CH3COO). Combined the advantages of ionic liquid and membrane separation, polyvinylidene fluoride, polysulfone and polyacrylonitrile membrane was chose to make ionic liquid supported liquid membrane by impregnation method. Compared the separation coefficient on different temperature of every kind of ionic liquid membrane for H2/N2 separation, it was found that the separation abilities of [BMIM] HCOO polysulfone membrane and polyacrylonitrile membrane were more bigger. The temperature conditions significantly affected the separation effect:at 30℃[BMIM]BF4 type poly-cvinylidene fluoride membrane, [BMIM]HCOO polysulfone membrane had the strong ability of H2/N2 separation, N2 could be separated off H2. 30℃in [BMIM]BF4 type polysulfone membrane separation N2/H2 ability was strong, H2 could be separated off N2.%选取2种市售离子液体1-丁基-3-甲基咪唑四氟硼酸盐([BMIM]BF4)与1-丁基-3-甲基咪唑六氟磷酸盐([BMIM]PF6),另采用离子交换法合成出2种离子液体1-丁基-3-甲基咪唑甲酸盐([BMIM]HCOO)与1-丁基-3-甲基咪唑乙酸盐([BMIM]CH3COO)。将离子液体与膜分离法优点相结合,选取聚偏氟乙烯膜、聚砜膜和聚丙烯腈膜并用浸渍法制备离子液体支撑液膜。比较不同温度下不同类型离子液膜对H2/N2的分离系数发现,[BMIM]HCOO型聚砜膜和聚丙烯腈膜对H2/N2分离系数较大。温度条件显著影响分离效果:30℃时[BMIM]BF4型聚偏氟乙烯膜、[BMIM]HCOO型聚砜膜分离H2/N2能力较强,可分离掉N2获得H2;30℃时[BMIM]BF4型聚砜膜分离N2/H2能力较强,可分离掉H2获得N2。

  16. Optimised extraction of heterocyclic aromatic amines from blood using hollow fibre membrane liquid-phase microextraction and triple quadrupole mass spectrometry.

    Science.gov (United States)

    Cooper, Kevin M; Jankhaikhot, Natcha; Cuskelly, Geraldine

    2014-09-05

    Heterocyclic aromatic amines (HCA) are carcinogenic mutagens formed during cooking of proteinaceous foods, particularly meat. To assist in the ongoing search for biomarkers of HCA exposure in blood, a method is described for the extraction from human plasma of the most abundant HCAs: 2-amino-1-methyl-6-phenylimidazo(4,5-b)pyridine (PhIP), 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) and 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline (4,8-DiMeIQx) (and its isomer 7,8-DiMeIQx), using hollow fibre membrane liquid-phase microextraction. This technique employs 2.5cm lengths of porous polypropylene fibres impregnated with organic solvent to facilitate simultaneous extraction from an alkaline aqueous sample into a low volume acidic acceptor phase. This low cost protocol is extensively optimised for fibre length, extraction time, sample pH and volume. Detection is by UPLC-MS/MS using positive mode electrospray ionisation with a 3.4min runtime, with optimum peak shape, sensitivity and baseline separation being achieved at pH 9.5. To our knowledge this is the first description of HCA chromatography under alkaline conditions. Application of fixed ion ratio tolerances for confirmation of analyte identity is discussed. Assay precision is between 4.5 and 8.8% while lower limits of detection between 2 and 5pg/mL are below the concentrations postulated for acid-labile HCA-protein adducts in blood.

  17. Chain ordering of hybrid lipids can stabilize domains in saturated/hybrid/cholesterol lipid membranes

    Science.gov (United States)

    Yamamoto, T.; Brewster, R.; Safran, S. A.

    2010-07-01

    We use a liquid-crystal model to predict that hybrid lipids (lipids that have one saturated and one unsaturated tail) can stabilize line interfaces between domains in mixed membranes of saturated lipids, hybrid lipids, and cholesterol (SHC membranes). The model predicts the phase separation of SHC membranes with both parabolic and loop binodals depending on the cholesterol concentration, modeled via an effective pressure. In some cases, the hybrid lipids can reduce the line tension to zero in SHC membranes at temperatures that approach the critical temperature as the pressure is increased. The differences in the hybrid saturated tail conformational order in bulk and at the interface are responsible for the reduction of the line tension.

  18. Flue gas treatment with membrane gas absorption

    NARCIS (Netherlands)

    Klaassen, R.; Feron, P.H.M.; Jansen, A.E.

    1998-01-01

    Dutch researchers from the TN0 Institute have developed a technique to carry out gas-liquid contacting operations using hollow fibre membranes in combination with an absorption liquid. The method known as membrane gas absorption, aims to combine the advantages of membrane technology (compactness, fl

  19. Liquid heat capacity lasers

    Science.gov (United States)

    Comaskey, Brian J.; Scheibner, Karl F.; Ault, Earl R.

    2007-05-01

    The heat capacity laser concept is extended to systems in which the heat capacity lasing media is a liquid. The laser active liquid is circulated from a reservoir (where the bulk of the media and hence waste heat resides) through a channel so configured for both optical pumping of the media for gain and for light amplification from the resulting gain.

  20. The Liquid Vapour Interface

    DEFF Research Database (Denmark)

    Als-Nielsen, Jens Aage

    1985-01-01

    In this short review we are concerned with the density variation across the liquid-vapour interface, i.e. from the bulk density of the liquid to the essentially zero density of the vapour phase. This density variation can in principle be determined from the deviation of the reflectivity from...

  1. Influence of gas-liquid two-phase flow on the anti-fouling performance of tubular membranes module for microfiltration%气液两相流下膜的抗污染性能研究

    Institute of Scientific and Technical Information of China (English)

    钱光磊; 周集体; 张劲松; 刘万涛

    2012-01-01

    Concentration polarization and cake layer formation on the surface of the membrane are two significant aspects resulting in membrane fouling. Aeration in tubular membrane module can form gas liquid two-phase flow, which can increase the shear force on the surface of tubular membrane and control the membrane fouling effectively. In this study, experiments were conducted under different gas flow rates in tubular membrane module. As it was shown, bubble rate and bubble frequency increased obviously as aeration increased yet membrane fouling rate decreased gradually so as to extend the membrane filtration operation time. It was found that the injected gas can increase turbulence on the surface of membrane to slow down transmembrane pressure rate and keep membrane fouling with a low flow rate, thus it can save the energy consumption and prolonging membrane service life.%膜表面浓差极化与滤饼层形成是膜污染的重要因素.通过管式膜曝气,使膜表面形成气液两相流,增大膜表面剪切力,能有效控制膜污染行为.实验通过微滤高岭土悬浊液,观察了不同曝气量下膜组件内气液流态,发现随着曝气量的增加,膜组件内气泡单元上升速率和频率加快,膜污染速率逐渐减小,延长了膜过滤运行时间.研究发现,气体的通入使膜表面湍流程度增大,有效减缓跨膜压力增长速率,并且实现了在较低流速下控制膜污染,节省了能耗成本,延长了膜使用寿命.

  2. Radiative Bulk Viscosity

    CERN Document Server

    Chen, X

    2001-01-01

    Viscous resistance to changes in the volume of a gas arises when different degrees of freedom have different relaxation times. Collisions tend to oppose the resulting departures from equilibrium and, in so doing, generate entropy. Even for a classical gas of hard spheres, when the mean free paths or mean flight times of constituent particles are long, we find a nonvanishing bulk viscosity. Here we apply a method recently used to uncover this result for a classical rarefied gas to radiative transfer theory and derive an expression for the radiative stress tensor for a gray medium with absorption and Thomson scattering. We determine the transport coefficients through the calculation of the comoving entropy generation. When scattering dominates absorption, the bulk viscosity becomes much larger than either the shear viscosity or the thermal conductivity.

  3. 陶瓷膜在卤制品加工废弃液微滤中的应用%Application of Ceramic Membrane on Microfiltration Waste Liquid in Marinating

    Institute of Scientific and Technical Information of China (English)

    李燕; 郑晓杰; 黄雪飞; 徐静

    2012-01-01

    探讨了陶瓷膜用于卤制加工废弃液微滤的工艺条件。研究不同预处理方法、膜孔径、操作温度、操作压力等因素对膜通量的影响,并通过正交实验确定微滤的最佳工艺参数为:预处理网筛300目、陶瓷膜孔径0.22μm、操作温度50℃、操作压力0.075 MPa,通过质量分数0.75%NaOH和0.5%柠檬酸复合清洗后,陶瓷膜的通量恢复率可达到94.1%。%Technical parameters of ceramic membrane microfiltration of waste liquid in marinating were studied.The effect of pretreatment method,membrane pore size,operation pressure,operation temperature on membrane flux were studied.The best parameters were determined by orthogonal experiment: pretreatment by 300mesh screen,membrane pore size 0.22 um,operation tempreature 50℃,operation pressure 0.075 MPa.The recovery percent of ceramic membrane was 94.1% after wash by 0.75% NaOH and 0.5% citric acid.

  4. Impact and Penetration of Nanoparticle Suspension Drops into Porous Membranes

    Science.gov (United States)

    Sahu, Rakesh; Yarin, Alexander; Pourdeyhimi, Behnam

    2014-03-01

    The impacts and dynamic penetration of drops with suspended nanoparticles into porous membranes are studied experimentally and theoretically. This type of penetration is radically different from the wettability-driven imbibition. Two types of membranes are used in the experiments: (i) glass fiber filter membrane (wettable) and (ii) PTFE depth filter (non-wettable). The nanoparticle entrainment and deposition inside the membrane bulk is used to mostly visualize the ultimate penetration fronts of the carrier fluid by observing the cut cross-sections of the filter membranes, albeit also provides an insight into potentially new applications like circuit printing on nonwovens. The experimental results demonstrate that during the dynamic focusing responsible for water penetration into micro- and nanopores, water can penetrate into a non-wettable porous medium (PTFE). Water also penetrates by the same focusing mechanism into the wettable glass fiber membrane, where it additionally spreads on a much longer time scale due to the wettability-driven flow. A theory explaining dynamic penetration of liquid into porous medium after drop impact is proposed. It is used to explain and predict water penetration into the non-wettable media after drop impact, and the results are compared with the experimental data. The work was supported by the Nonwovens Cooperative Research Center (NCRC).

  5. Macromolecular liquids

    Energy Technology Data Exchange (ETDEWEB)

    Safinya, C.R.; Safran, S.A. (Exxon Research and Engineering Co., Annandale, NJ (US)); Pincus, P.A. (Univ. of California at Santa Barbara, Santa Barbara, CA (US))

    1990-01-01

    Liquids include a broad range of material systems which are of high scientific and technological interest. Generally speaking, these are partially ordered or disordered phases where the individual molecular species have organized themselves on length scales which are larger than simple fluids, typically between 10 Angstroms and several microns. The specific systems reported on in this book include membranes, microemulsions, micelles, liquid crystals, colloidal suspensions, and polymers. They have a major impact on a broad spectrum of technological industries such as displays, plastics, soap and detergents, chemicals and petroleum, and pharmaceuticals.

  6. Probing Lipid Membrane Rafts (Microdomains) with Fluorescent Phospholipids

    Science.gov (United States)

    Gu, Yongwen; Mitchel, Drake

    2011-10-01

    Membrane rafts are enriched in sphingolipids and cholesterol, they exist in a more ordered state (the liquid-ordered phase; lo) than the bulk membrane (the liquid-disordered phase; ld). Ternary mixtures of palmitoyl-oleoyl-phosphocholine (POPC; 16:0,18:1 PC), sphingomyelin (SPM), and cholesterol (Chol) form membrane rafts over a wide range of molar ratios. We are examining the ability of two fluorescent probes, NBD linked to di-16:0 PE which partitions into the lo phase, and NBD linked to di-18:1 PE which partitions into the ld phase, to detect these two phases. We are also examining the effect of the highly polyunsaturated phospholipid stearoyl-docosahexanoyl-phosphocholine (SDPC; 18:0, 22:6 PC) on the size and stability of POPC/SPM/Chol membrane rafts. We report on the fluorescence lifetime and anisotropy decay dynamics of two fluorescent probes. Data were acquired via frequency-domain measurements from 5 to 250 MHz.

  7. 中空纤维膜液相微萃取技术及其应用进展%Hollow fiber membrane liquid-phase microextraction technique and its application

    Institute of Scientific and Technical Information of China (English)

    宋林; 乐健; 洪战英

    2014-01-01

    Hollow fiber membrane liquid-phase microextraction technique is a kind of environment friendly sample pretreatment technique,which integrates sampling,extraction and concentration into one.In this paper,the structure characteristics of porous hollow fiber membrane,the microextraction installation,the extraction pattern,the applications of hollow fiber membrane liquid-phase microextraction in different samples,such as environmental samples and biological body fluid were introduced,and the extraction influential factors were analyzed as well.%中空纤维膜液相微萃取技术是一种集采样、萃取和浓缩于一体,环境友好的样品前处理技术.本文介绍了多孔中空纤维膜的结构特点、微萃取装置以及萃取模式,对影响其萃取效果的因素加以分析,同时介绍了中空纤维膜液相微萃取技术在环境和生物体液等样品中的应用.

  8. The Molecules of the Cell Membrane.

    Science.gov (United States)

    Bretscher, Mark S.

    1985-01-01

    Cell membrane molecules form a simple, two-dimensional liquid controlling what enters and leaves the cell. Discusses cell membrane molecular architecture, plasma membranes, epithelial cells, cycles of endocytosis and exocytosis, and other topics. Indicates that some cells internalize, then recycle, membrane area equivalent to their entire surface…

  9. Ion Sensor Based on Fluorous Liquid Phase Sensing Membrane with High Selectivity%基于高选择性氟液相传感膜的离子传感器

    Institute of Scientific and Technical Information of China (English)

    黄美荣; 丁永波; 施凤英; 李新贵

    2012-01-01

    本文基于国外最新研究工作,系统总结了电位型传感器中的一种新型传感膜——氟液相传感膜。对构成氟液相传感膜的所有组分:氟溶剂、溶解在氟溶剂中的亲氟离子交换剂和亲氟离子载体以及对氟溶剂起支撑作用的惰性微孔支撑膜等进行了全面归纳,重点讨论了这4种因素对传感器性能的影响。指出目前使用的亲氟离子交换剂分子和亲氟离子载体分子均含有2—8根链长为6—10的全氟碳链。氟液相传感膜具有优于传统PVC膜的检测下限,其中通过三维有序大孔碳以固体接触方式构建的氟液相传感膜电位传感器对Ag+的探测下限可达3.8×10-11mol/L。氟液相传感膜还具有十分出色的选择性,无任何离子载体的空白氟液相传感膜的选择系数对数值log Kpi,oJt的跨越宽度达16—18,比无载体的PVC膜宽8个数量级。这类全新的氟液相传感膜构建的电位型离子传感器将以其独特的优势在环境监测、食品卫生,尤其是在医疗诊断、生物物质检测中展示出不可替代的作用。%New fluorous liquid sensing membranes for the fabrication of potentiometric sensors are systematically summarized. Fluorous solvents, fluorophilic ion-exchangers and fluorophilic ionophores doped in the fluorous solvents, as well as inert fluorous porous supports, are reviewed thoroughly. The influence of the four factors on the performance of potentiometric sensors is concentrated. It is pointed out that both the fluorophilic ion- exchangers and ionophores used so far contain 2--8 perfluoroalkyl chains which are composed of 6--10 carbon atoms in each chain. Such a fluorous liquid phase sensing membrane possesses a superior lower detection limit compared with conventional poly(vinyl chloride)(PVC) membranes. For Ag( I ) potentiometric sensor based on the fluorous liquid membrane with solid contact through three-dimensionally ordered macroporous (3DOM) carbon, the lower

  10. 煤气化含酚废水的液膜法处理研究%STUDIES ON THE TREATMENT OF PHENOL-CONTAINING WASTEWATER FROM GASIFIERS BY EMULSION LIQUID MEMBRANE

    Institute of Scientific and Technical Information of China (English)

    王祥远

    2011-01-01

    采用乳状液膜法处理鲁奇炉煤气化废水,通过单因素实验,研究了表面活性剂用量、制乳转速、NaOH浓度、乳水比对乳状液膜法处理废水效果的影响.实验还比较了乳状液膜法与二异丙醚(DIPE)、甲基异丁基甲酮(MIBK)两种溶剂萃取法的处理效果.结果表明,表面活性剂用量、制乳转速、NaOH浓度、乳水比的最优条件分别是4%、5000 r/min、4%、1:1.5.乳状液膜法在脱酚效率上高于以二异丙醚和甲基异丁基甲酮为溶剂的液液萃取,但处理后废水COD较高.%Emulsion liquid membrane treatment of Lurgi coal gasification wastewater has been studied by using single factor experiments. The effect of the surfactant amount, emulsification speed, NaOH concentration, the ratio of emulsion and water, stirring speed on the extraction ratio of phenol are investigated. And the performances of emulsion liquid membrane, solvent extraction with DIPE and MIBK are compared. The experimental results indicate that the optimal conditions of the surfactant amount, emulsification speed, NaOH concentration, and the ratio of emulsion and water are 4%, 5 000 r/min, 8%, and 1 : 1. 5. The performance of phenols removal and COD removal with emulsion liquid membrane are higher and lower than that of solvent extraction with DIPE and MIBK, respectively.

  11. Research on the treatment of phenyl guanidine wastewater by emulsion liquid membrane%乳状液膜法处理苯基胍废水的试验研究

    Institute of Scientific and Technical Information of China (English)

    欧云川; 宋红; 马文静; 程迪

    2011-01-01

    The treatment method of phenyl guanidine wastewater was studied with emulsion liquid membrane technique.Factors affecting efficiency of removal of CODc,were investigated with a selected system of liquid membrane.Experimental results show that the phenylamine and the phenyl guanidine with a concentration of 2504 mg/L and 5985 mg/L separately in the wastewater from process of phenyl guanidine can be reduced by as much as 99%by the emulsion liquid membrane,under the operation conditions followed:the w(surfactant L- 113A) = 3%,φ(additive) =6%,φ(HCl solution) =10%and R_(oi)=2:1,R_(ew) of 1:8,pH 8~9 and retention time of 15minutes.The removal rate of COD_(Cr) can reach 74.5%as well.%研究了苯基胍废水的乳状液膜处理方法,选择了最佳的液膜体系,考察了各种因素对COD_(Cr)去除率的影响。结果表明:以w(表面活性剂L-113A)为3%、φ(添加剂)为6%、φ(盐酸)为10%、油内比R_(oi)为2:1的液膜体系,当乳水比R_(cw)=1:8、外水相pH值为8~9、传质15min,可使苯胺和苯基胍含量分别为2504mg/L和5985mg/L的苯基胍废水,去除率达99%以上,同时COD_(Cr)去除率达74.5%。

  12. Eco Issues in Bulk Materials Handling Technologies in Ports

    Directory of Open Access Journals (Sweden)

    Nenad Zrnić

    2011-09-01

    Full Text Available This paper deals with eco issues in bulk materials handling in ports. Solid, free-flowing materials are said to be in bulk. Bulk materials handling is very difficult, because it incorporates all the features of liquids, gasses and mass solids. Energy efficiency, dust emissions in nearby environment, dust explosions, jamming, noise, handling of hazardous materials and protection of materials from contamination are issues that will be considered in this paper. Here are also presented possible solutions for some of these issues

  13. Alternative technology of nanoparticles consolidation in the bulk material

    Directory of Open Access Journals (Sweden)

    VOLKOV Georgiy Michailovich

    2016-02-01

    Full Text Available Theoretical bases and technological principles of single-stages nanoparticles conso-lidation into bulk material were offered. The theory was implemented on the model system of carbon-carbon in the process of high-temperature pyrolysis of hydrocar-bons. The bulk carbon nanomaterial with unique technical properties was produced. That made it possible to create engineering products which technical characteristics are higher than the existing level in the world. The proposed theory can be adapted to other gas-phase, liquid phase and secondary crystallization processes to create bulk nanomaterials of another chemical composition with no less unique properties.

  14. Probing Induced Structural Changes in Biomimetic Bacterial Cell Membrane Interactions with Divalent Cations

    Energy Technology Data Exchange (ETDEWEB)

    Holt, Allison M [ORNL; Standaert, Robert F [ORNL; Jubb, Aaron M [ORNL; Katsaras, John [ORNL; Johs, Alexander [ORNL

    2017-01-01

    Biological membranes, formed primarily by the self-assembly of complex mixtures of phospholipids, provide a structured scaffold for compartmentalization and structural processes in living cells. The specific physical properties of phospholipid species present in a given membrane play a key role in mediating these processes. Phosphatidylethanolamine (PE), a zwitterionic lipid present in bacterial, yeast, and mammalian cell membranes, is exceptional. In addition to undergoing the standard lipid polymorphic transition between the gel and liquid-crystalline phase, it can also assume an unusual polymorphic state, the inverse hexagonal phase (HII). Divalent cations are among the factors that drive the formation of the HII phase, wherein the lipid molecules form stacked tubular structures by burying the hydrophilic head groups and exposing the hydrophobic tails to the bulk solvent. Most biological membranes contain a lipid species capable of forming the HII state suggesting that such lipid polymorphic structural states play an important role in structural biological processes such as membrane fusion. In this study, the interactions between Mg2+ and biomimetic bacterial cell membranes composed of PE and phosphatidylglycerol (PG) were probed using differential scanning calorimetry (DSC), small-angle x-ray scattering (SAXS), and fluorescence spectroscopy. The lipid phase transitions were examined at varying ratios of PE to PG and upon exposure to physiologically relevant concentrations of Mg2+. An understanding of these basic interactions enhances our understanding of membrane dynamics and how membrane-mediated structural changes may occur in vivo.

  15. Bulk-Fill Resin Composites

    DEFF Research Database (Denmark)

    Benetti, Ana Raquel; Havndrup-Pedersen, Cæcilie; Honoré, Daniel;

    2015-01-01

    the restorative procedure. The aim of this study, therefore, was to compare the depth of cure, polymerization contraction, and gap formation in bulk-fill resin composites with those of a conventional resin composite. To achieve this, the depth of cure was assessed in accordance with the International Organization...... for Standardization 4049 standard, and the polymerization contraction was determined using the bonded-disc method. The gap formation was measured at the dentin margin of Class II cavities. Five bulk-fill resin composites were investigated: two high-viscosity (Tetric EvoCeram Bulk Fill, SonicFill) and three low......-viscosity (x-tra base, Venus Bulk Fill, SDR) materials. Compared with the conventional resin composite, the high-viscosity bulk-fill materials exhibited only a small increase (but significant for Tetric EvoCeram Bulk Fill) in depth of cure and polymerization contraction, whereas the low-viscosity bulk...

  16. The Incredible Bulk

    CERN Document Server

    Fukushima, Keita; Kumar, Jason; Sandick, Pearl; Yamamoto, Takahiro

    2014-01-01

    Recent experimental results from the LHC have placed strong constraints on the masses of colored superpartners. The MSSM parameter space is also constrained by the measurement of the Higgs boson mass, and the requirement that the relic density of lightest neutralinos be consistent with observations. Although large regions of the MSSM parameter space can be excluded by these combined bounds, leptophilic versions of the MSSM can survive these constraints. In this paper we consider a scenario in which the requirements of minimal flavor violation, vanishing $CP$-violation, and mass universality are relaxed, specifically focusing on scenarios with light sleptons. We find a large region of parameter space, analogous to the original bulk region, for which the lightest neutralino is a thermal relic with an abundance consistent with that of dark matter. We find that these leptophilic models are constrained by measurements of the magnetic and electric dipole moments of the electron and muon, and that these models have ...

  17. Creating bulk nanocrystalline metal.

    Energy Technology Data Exchange (ETDEWEB)

    Fredenburg, D. Anthony (Georgia Institute of Technology, Atlanta, GA); Saldana, Christopher J. (Purdue University, West Lafayette, IN); Gill, David D.; Hall, Aaron Christopher; Roemer, Timothy John (Ktech Corporation, Albuquerque, NM); Vogler, Tracy John; Yang, Pin

    2008-10-01

    Nanocrystalline and nanostructured materials offer unique microstructure-dependent properties that are superior to coarse-grained materials. These materials have been shown to have very high hardness, strength, and wear resistance. However, most current methods of producing nanostructured materials in weapons-relevant materials create powdered metal that must be consolidated into bulk form to be useful. Conventional consolidation methods are not appropriate due to the need to maintain the nanocrystalline structure. This research investigated new ways of creating nanocrystalline material, new methods of consolidating nanocrystalline material, and an analysis of these different methods of creation and consolidation to evaluate their applicability to mesoscale weapons applications where part features are often under 100 {micro}m wide and the material's microstructure must be very small to give homogeneous properties across the feature.

  18. Explosive bulk charge

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Jacob Lee

    2015-04-21

    An explosive bulk charge, including: a first contact surface configured to be selectively disposed substantially adjacent to a structure or material; a second end surface configured to selectively receive a detonator; and a curvilinear side surface joining the first contact surface and the second end surface. The first contact surface, the second end surface, and the curvilinear side surface form a bi-truncated hemispherical structure. The first contact surface, the second end surface, and the curvilinear side surface are formed from an explosive material. Optionally, the first contact surface and the second end surface each have a substantially circular shape. Optionally, the first contact surface and the second end surface consist of planar structures that are aligned substantially parallel or slightly tilted with respect to one another. The curvilinear side surface has one of a smooth curved geometry, an elliptical geometry, and a parabolic geometry.

  19. 乳状液膜法处理鲁奇气化含酚废水的研究%Studies on the Treatment of Phenol-containing Wastewater from Lurgi Gasifiers by Emulsion Liquid Membrane

    Institute of Scientific and Technical Information of China (English)

    盖恒军; 王祥远; 吴文颖

    2011-01-01

    采用乳状液膜法处理鲁奇炉煤气化废水,通过单因素实验,研究了表面活性剂用量、制乳转速、NaOH浓度、乳水比对乳状液膜法处理废水效果的影响.实验还比较了乳状液膜法与二异丙醚、甲基异丁基甲酮两种溶剂萃取法的处理效果.结果表明,表面活性剂用量、制乳转速、NaOH质量分数、乳水比的最优条件分别是4%、5 000r/min、4%、1∶1.5.乳状液膜法在脱酚效率上高于以二异丙醚和甲基异丁基甲酮为溶剂的液液萃取,但处理后废水COD较高.%The Emulsion liquid membrane treatment of Lurgi coal gasification wastewater has been studied by using single factor experiments. The effect of the surfactant amount, emulsification speed, NaOH concentration, the ratio of emulsion and water and the stirring speed on the extraction ratio of phenol are investigated. Besides, the performances of emulsion liquid membrane, solvent extraction with DIPE and MIBK are compared. The experimental results indicate that the optimal conditions of the surfactant amount, emulsification speed, NaOH concentration, and the ratio of emulsion and water are 4%, 5000r/min, 4%, and 1:1.5, respectively. The phenol removal efficiency of the emulsion liquid membrane method is better than that of the liquid-liquid solvent extraction method based on DIPE and MIBK, but the COD content in the treated wastewater is a bit high.

  20. Proton Diffusion Coefficient in Electrospun Hybrid Membranes by Electrochemical Impedance Spectroscopy.

    Science.gov (United States)

    Dos Santos, Leslie; Laberty-Robert, Christel; Maréchal, Manuel; Perrot, Hubert; Sel, Ozlem

    2015-09-15

    Electrochemical Impedance Spectroscopy (EIS) was, for the first time, used to estimate the global transverse proton diffusion coefficient, D(H+)(EHM), in electrospun hybrid conducting membranes (EHMs). In contrast to conventional impedance spectroscopy, EIS measurements were performed at room temperature with a liquid interface. In this configuration, the measure of the bulk proton transport is influenced by the kinetics of the transfer of proton at the solid/liquid interface. We demonstrated that the use of additives in the process of the membrane impacts the organization of the hydrophilic domains and also the proton transport. The D(H+)(EHM) is close to 1.10(-7) cm(2) s(-1) (± 0.1.10(-7) cm(2) s(-1)) for the EHMs without additive, whereas it is 4.10(-6) cm(2) s(-1) (± 0.4.10(-6) cm(2) s(-1)) for EHMs with additives.