WorldWideScience

Sample records for bulk liquid membrane

  1. Pertraction of zinc through the bulk liquid membrane

    International Nuclear Information System (INIS)

    In this paper are presented the results of the study of zinc transport through layered bulk liquid membrane. Scheme of a two-compartment pertraction cell is given. Proposed model of pertraction describes well experimental data. The best fit was found when on both sides reversible reactions were supposed. When irreversible reactions were supposed, kF = 0.999 m-2 min-1 and kR = 1.80 m-2 min-1. From these values it follows that reaction rate on the stripping interface is higher than on the upstream interface. It is supposed to use these rate constants in modeling pertraction in hollow-fibre contactors. Flux of zinc through the membrane, JR, increases with increasing frequency of membrane phase mixers reaching a plateau region at frequency of about 90 min-1. Above 135 min-1 interfaces become unstable. The existence of plateau supports the assumption of negligible diffusional resistance at interfaces and in the membrane. 3 figs., 7 refs

  2. Selective transport of Ag(Ⅰ)ion across a bulk liquid and polymer membranes incorporated with di-N-benzylated O3N2 donor macrocycles

    Institute of Scientific and Technical Information of China (English)

    A.Nezhadali

    2010-01-01

    The selective bulk liquid membrane and polymer membrane transports of Ag(Ⅰ)from an aqueous solution containing seven metal cations,Co(Ⅱ),Ni(Ⅱ),Cu(Ⅱ),Zn(Ⅱ),Ag(Ⅰ),Cd(Ⅱ)and Pb(Ⅱ),was studied.The source phases contained equimolar concentrations of the above-mentioned cations,with the source and receiving phases being buffered at pH 5.0 and 3.0,respectively.Ag(Ⅰ)ion transport occurred with a good efficiency from the aqueous source phases across the bulk liquid membrane and polymer membrane(derived from cellulose triacetate)containing ligand 1 as the ionophores,into the aqueous receiving phases.Clear transport selectivity for Ag(Ⅰ)was observed using ligand 1.There was no selectivity for the cations using ligand 2 in the both bulk liquid membrane and polymer membrane transports.

  3. Hybrid biofilm-membrane bioreactor (Bf-MBR) for minimization of bulk liquid-phase organic substances and its positive effect on membrane permeability.

    Science.gov (United States)

    Sun, F Y; Li, P; Li, J; Li, H J; Ou, Q M; Sun, T T; Dong, Z J

    2015-12-01

    Four biofilm membrane bioreactors (Bf-MBRs) with various fixed carrier volumes (C:M) were operated in parallel to investigate the effect of attached-growth mode biomass involvement to the change of liquid-phase organics characteristics and membrane permeability, by comparing with conventional MBR. The experiments displayed that C:M and co-existence of biofilm with suspended solids in Bf-MBRs resulted in slight difference in pollutants removal effectiveness, and in rather distinct biomass properties and bacterial activities. The membrane permeability and specific resistance of bulk suspension of Bf-MBRs related closely with the liquid-phase organic substance, including soluble microbial products (SMP) and biopolymer cluster (BPC). Compared with conventional MBR, Bf-MBR with proper C:M had a low total biomass content and food-chain, where biofilm formation and its dominance affected liquid-phase organics, especially through reducing their content and minimizing strongly and weakly hydrophobic components with small molecular weight, and thus to mitigate membrane fouling significantly. PMID:26454042

  4. Kinetic studies on the extraction of uranium(VI) from phosphoric acid medium by bulk liquid membrane containing di-2-ethylhexyl phosphoric acid

    International Nuclear Information System (INIS)

    To go through the first stage of industrial solvent extraction process in order to recover uranium from phosphate rocks by liquid membrane techniques, as a simple model, the kinetics of facilitated transport of uranium(VI) from a dilute phosphoric acid medium into more concentrated phosphoric acid media as a receiving phase through a bulk liquid membrane containing di-2-ethylhexyl phosphoric acid as a carrier was studied. The influence of phosphoric acid concentration in the source and receiving phases, carrier concentration, type of solvent, stirring speed and temperature were investigated. The kinetic parameters (ke, ks, tmax, Jmax) were calculated for the interface reactions assuming two consecutive, irreversible first-order reactions. The activation energy values were calculated as 29.40 and 19.51 kJ mol-1 for extraction and stripping, respectively. The values of calculated activation energy indicated that both the extraction and stripping processes were controlled by mixed regime (both kinetic and diffusion). In addition, the influence of adding trioctyl-phosphine oxide into the membrane phase as a synergic agent on the transport kinetics was determined. (author)

  5. Oscillating annular liquid membranes

    International Nuclear Information System (INIS)

    The response of annular liquid membranes (e.g. used as protection systems in laser fusion reactors) to sinusoidal mass flow rate fluctuations at the nozzle exit is analyzed as a function of the amplitude and frequency of the axial velocity fluctuations at the nozzle exit and thermodynamic compression of the gas enclosed by the membrane. The pressure of the gases enclosed by the annular membrane and the axial distance at which the annular membrane merges on the symmetry axis are periodic functions of time which have the same period as that of the mass flow rate fluctuations at the nozzle exit. They are also nearly sinusoidal functions of time for small amplitudes of the mass flow rate fluctuations at the nozzle exit, and exhibit delay and lag times with respect to the sinusoidal axial velocity fluctuations at the nozzle exit. The delay and the lag times are functions of the amplitude and frequency of the mass flow rate fluctuations at the nozzle exit and the polytropic exponent. The amplitudes of both the pressure of the gases enclosed by the annular liquid membrane and the convergence length increase and decrease, resp., as the amplitude and frequency of the mass flow rate fluctuations at the nozzle exit, resp., are increased. They also increase as the polytropic exponent is increased. (orig.)

  6. 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...

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

    OpenAIRE

    Ng, Yee Sern; Jayakumar, N.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 ...

  8. 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...

  9. Membrane assisted liquid-liquid extraction of cerium

    International Nuclear Information System (INIS)

    Membrane assisted liquid-liquid extraction of cerium was investigated, with emphasis placed on the study of the reaction chemistry and the kinetics of non-dispersive solvent extraction and stripping with microporous membranes. A bulk liquid membrane process was developed for the purification of cerium(IV) from sulfate solutions containing other rare earth elements. The cerium process was studied in both a flat sheet contained liquid membrane configuration and with hollow fibre contactors. Di-2-ethylhexyl phosphoric acid (DEHPA) was identified as a suitable extractant for cerium(IV) from sulfuric acid solution, with due consideration of factors such as extraction ability, resistance to degradation, solvent selectivity and potential for sulfate transfer into a strip solution. A detailed study of the extraction of cerium(IV) with DEHPA defined the extraction reaction chemistry. The Ce/DEHPA/sulfate system was also investigated with a flat sheet bulk liquid membrane configuration, using both sulfuric and hydrochloric acid as receiver solutions. These tests identified that hydrophobic membranes provide better mass transfer for extraction and hydrophilic membranes are better for stripping. The presence of an impurity, mono 2-ethylhexyl phosphoric acid (MEHPA), was found to have a dramatic accelerating effect on the rate of the chemical extraction reaction. This was attributed to its higher interfacial activity and population compared to DEHPA, and the fact that MEHPA was also found to be an active carrier for cerium(IV). The mass transfer rate of membrane assisted extraction and stripping of cerium, using hydrophobic and hydrophilic microporous membranes, respectively, was investigated using a modified Lewis-type cell. It was quantitatively demonstrated that the extraction process was mainly controlled by membrane diffusion and the stripping process was controlled by the chemical reaction rate, with membrane diffusion becoming important at low distribution coefficients

  10. 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.

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

    OpenAIRE

    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 sructured packing elements. The penetration model was slightly modified, so that it can describe systems without liquid bulk. A comparison is made between the results obtained with the modified mo...

  12. Zinc separation by using a liquid membrane

    International Nuclear Information System (INIS)

    We have performed the isotopic separation of 64Zn and 66Zn by using a liquid membrane with chloroform diluent and dicyclohexano - 18 - crown - 6 as carrier. The isotopic separation factor was the same as for liquid-liquid extraction

  13. 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.

  14. Method of fabrication of supported liquid membranes

    Science.gov (United States)

    Luebke, David R.; Hong, Lei; Myers, Christina R.

    2015-11-17

    Method for the fabrication of a supported liquid membrane having a dense layer in contact with a porous layer, and a membrane liquid layer within the interconnected pores of the porous layer. The dense layer is comprised of a solidified material having an average pore size less than or equal to about 0.1 nanometer, while the porous layer is comprised of a plurality of interconnected pores and has an average pore size greater than 10 nanometers. The supported liquid membrane is fabricated through the preparation of a casting solution of a membrane liquid and a volatile solvent. A pressure difference is established across the dense layer and porous layer, the casting solution is applied to the porous layer, and the low viscosity casting solution is drawn toward the dense layer. The volatile solvent is evaporated and the membrane liquid precipitates, generating a membrane liquid layer in close proximity to the dense layer.

  15. 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.

  16. Membrane separation of ionic liquid solutions

    Energy Technology Data Exchange (ETDEWEB)

    Campos, Daniel; Feiring, Andrew Edward; Majumdar, Sudipto; Nemser, Stuart

    2015-09-01

    A membrane separation process using a highly fluorinated polymer membrane that selectively permeates water of an aqueous ionic liquid solution to provide dry ionic liquid. Preferably the polymer is a polymer that includes polymerized perfluoro-2,2-dimethyl-1,3-dioxole (PDD). The process is also capable of removing small molecular compounds such as organic solvents that can be present in the solution. This membrane separation process is suitable for drying the aqueous ionic liquid byproduct from precipitating solutions of biomass dissolved in ionic liquid, and is thus instrumental to providing usable lignocellulosic products for energy consumption and other industrial uses in an environmentally benign manner.

  17. Separation of metals by supported liquid membranes

    Energy Technology Data Exchange (ETDEWEB)

    Takigawa, D.Y.

    1990-12-31

    A supported liquid membrane system for the separation of a preselected chemical species within a feedstream, preferably an aqueous feedstream, includes a feed compartment containing a feed solution having at least one preselected chemical species therein, a stripping compartment containing a stripping solution therein, and a microporous polybenzimidazole membrane situated between the compartments, the microporous polybenzimidazole membrane containing an extractant mixture selective for the preselected chemical species within the membrane pores is disclosed along with a method of separating preselected chemical species from a feedstream with such a system, and a supported liquid membrane for use in such a system.

  18. Homogenizer of cement mix with liquid and bulk radioactive wastes

    International Nuclear Information System (INIS)

    The lid of the homogenizer vessel with a stirrer and with bulk and liquid inlets is firmly attached to the homogenizer frame. The mixing vessel is screwed onto the lid and is connected to the frame with two moving arms. This allows to separate the mixing vessel from the lid without having to disconnect the supplies of bulk and liquid materials. The vessel is attached to swing arms pivoted in joints, which allows servicing, turning and tipping the vessel, thereby facilitating its emptying. This facilitates cleaning and reduces the maintenance time, thus increasing the safety of personnel. (J.B.). 2 figs

  19. Permeation of lanthanum through supported liquid membranes

    International Nuclear Information System (INIS)

    The mechanism of lanthanum transport through a supported liquid membrane is presented. The membrane consisted of a Teflon millipore membrane with a kerosene solution of di(2-ethylhexyl) phosphoric acid (HDEHP) as a mobile carrier held within the pores by capillary forces. Interposing the liquid membrane between two aqueous solutions with different pH values, lanthanum was transported and concentrated from the high pH solution to the low pH solution across the liquid membrane. The effects of HDEHP concentration in the membrane solution and of the lanthanum concentration and pH in the aqueous phases on the permeation rates of lanthanum were investigated. It was observed that the permeation rates decrease drastically by the addition of surfactant to the membrane phase. The permeation rates of lanthanum can be explained by a permeation model which includes the extraction and the stripping reaction at the membrane interfaces and the diffusion process of the complex formed between lanthanum and HDEHP through the membrane in addition to the diffusion process of lanthanum in the aqueous film adjacent to the membrane

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

    International Nuclear Information System (INIS)

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

  1. Hard-body models of bulk liquid crystals.

    Science.gov (United States)

    Mederos, Luis; Velasco, Enrique; Martínez-Ratón, Yuri

    2014-11-19

    Hard models for particle interactions have played a crucial role in the understanding of the structure of condensed matter. In particular, they help to explain the formation of oriented phases in liquids made of anisotropic molecules or colloidal particles and continue to be of great interest in the formulation of theories for liquids in bulk, near interfaces and in biophysical environments. Hard models of anisotropic particles give rise to complex phase diagrams, including uniaxial and biaxial nematic phases, discotic phases and spatially ordered phases such as smectic, columnar or crystal. Also, their mixtures exhibit additional interesting behaviours where demixing competes with orientational order. Here we review the different models of hard particles used in the theory of bulk anisotropic liquids, leaving aside interfacial properties and discuss the associated theoretical approaches and computer simulations, focusing on applications in equilibrium situations. The latter include one-component bulk fluids, mixtures and polydisperse fluids, both in two and three dimensions, and emphasis is put on liquid-crystal phase transitions and complex phase behaviour in general. PMID:25335432

  2. Inclusion of thiol DAB dendrimer/CdSe quantum dots based in a membrane structure: Surface and bulk membrane modification

    International Nuclear Information System (INIS)

    Highlights: ► Fluorescent nanocomposite based in CdSe quantum dots (QDs) coated by thiol polypropylenimine (DAB). ► Bulk chemical characterization by TEM and EDAX ► Inclusion of the S-DAB-CdSe QDs in a cellulosic support and its characterization by Fluorescence and XPS. ► Electrical characterization by Impedance Spectroscopy of dry and wet samples containing a heavy metal. -- Abstract: The behavior of a fluorescent nanocomposite, obtained by means of a thiol polypropylenimine dendrimer of third generation coated with CdSe quantum dots, and embedded in a hydrophilic cellulosic membrane as support is electrochemically studied in order to evaluate its applicability as a sensor in liquid media. The characterization of the nanocomposite by TEM and EDAX shows uniform nano morphology (size comprised in the range 60–90 nm) and composition, respectively. The analysis of the engineered hybrid cellulose-dendrimer quantum dots material by confocal fluorescence microscopy indicates almost mono-dispersion distribution of the nanocomposite when irradiated under UV light, while its presence on the film surface was determined by X-ray photoelectron spectroscopy. Impedance spectroscopy measurements performed with dry membrane samples show a decrease in the conductivity and dielectric constant of the modified membrane in comparison with the raw support. Electrical changes in the modified film associated to the presence of Cd(II) uptakes from a Cl2Cd solution were also obtained. These results support the possible application of this nanocomposite material as heavy metal sensor in liquid media

  3. Primary metals extraction by liquid membranes

    International Nuclear Information System (INIS)

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

  4. Polymer single crystal membrane from liquid/liquid interface

    Science.gov (United States)

    Wang, Wenda; Li, Christopher; Soft Matter Research Group-Drexel University Team

    2013-03-01

    Vesicles, mimicking the structure of cell membrane at the molecular scale, are small membrane-enclosed sacks that can store or transport substances. The weak mechanical properties and the nature of environment-sensitivity of the current available vesicles: liposomes, polymersomes, colloidsomes limit their applications as an excellent candidate for targeting delivery of drugs/genes in biomedical engineering and treatment. Recently, we developed an emulsion-based method to grow curved polymer single crystals. Varying the polymer concentration and/or the emulsification conditions (such as surfactant concentration, water-oil volume ratio), curved crystals with different sizes and different openness could be obtained. This growing process was attributed to polymer crystal growth along the liquid/liquid interface. In addition, the liquid/liquid interfacial crystal growth is promising for synthesis of enclosed hollow sphere.

  5. Cellulose multilayer Membranes manufacture with Ionic liquid

    KAUST Repository

    Livazovic, S.

    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.

  6. 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...

  7. Standard practice for bulk sampling of liquid uranium hexafluoride

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2001-01-01

    1.1 This practice covers methods for withdrawing representative samples of liquid uranium hexafluoride (UF6) from bulk quantities of the material. Such samples are used for determining compliance with the applicable commercial specification, for example Specification C787 and Specification C996. 1.2 It is assumed that the bulk liquid UF6 being sampled comprises a single quality and quantity of material. This practice does not address any special additional arrangements that might be required for taking proportional or composite samples, or when the sampled bulk material is being added to UF6 residues already in a container (“heels recycle”). 1.3 The number of samples to be taken, their nominal sample weight, and their disposition shall be agreed upon between the parties. 1.4 The scope of this practice does not include provisions for preventing criticality incidents. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of th...

  8. Supported liquid membranes technologies in metals removal from liquid effluents

    Directory of Open Access Journals (Sweden)

    de Agreda, D.

    2011-04-01

    Full Text Available The generation of liquid effluents containing organic and inorganic residues from industries present a potential hazardousness for environment and human health, being mandatory the elimination of these pollutants from the respective solutions containing them. In order to achieve this goal, several techniques are being used and among them, supported liquid membranes technologies are showing their potential for their application in the removal of metals contained in liquid effluents. Supported liquid membranes are a combination between conventional polymeric membranes and solvent extraction. Several configurations are used: flat-sheet supported liquid membranes, spiral wounds and hollow fiber modules. In order to improve their effectiveness, smart operations have been developed: non-dispersive solvent extraction, non-dispersive solvent extraction with strip phase dispersion and hollow fiber renewal liquid membrane. This paper overviewed some of these supported liquid membranes technologies and their applications to the treatment of metal-bearing liquid effluents.

    La generación, por parte de las industrias, de efluentes líquidos conteniendo sustancias orgánicas e inorgánicas, es un peligro potencial tanto para los humanos como para el medio ambiente, siendo necesaria la eliminación de estos elementos tóxicos de las disoluciones que los contienen. Para conseguir este fin, se están aplicando diversas técnicas y entre ellas las tecnologías de membranas líquidas soportadas, están demostrando sus aptitudes para la eliminación de metales contenidos en efluentes líquidos. Las membranas líquidas soportadas, resultan de la unión de las membranas poliméricas y de la tecnología de extracción líquido-líquido. Este tipo de membranas se pueden utilizar en diversas configuraciones: plana, módulo en fibra hueca y módulo en espiral y para aumentar su efectividad se están desarrollando las llamadas operaciones avanzadas: extracción no

  9. Thermodynamic regularities in compressed liquids: II. The reduced bulk modulus

    International Nuclear Information System (INIS)

    In a previous work, we analysed some regularities found in the behaviour of the thermal expansion coefficient, αp, in compressed liquids. We confirmed that a given liquid presents a characteristic pressure range in which the condition (∂αp/∂T)p=0 is fulfilled within a narrow range of reduced densities. We also found that the density at which the condition (∂αp/∂T)p=0 is satisfied, ρα, decreases with temperature, a key feature not described before. Earlier studies by other authors suggested that similar regularities are expected for the reduced bulk modulus, B. We present here a detailed analysis of the temperature and density dependence of B from existing experimental results at high pressures. Several liquids have been analysed: argon, krypton, xenon, ethylene, tetrafluoromethane, trifluoromethane, carbon dioxide, carbon disulfide, n-butane, n-hexane, toluene, ethanol, 1-hexanol, m-cresol, and quinoline. We locate that the density ρB that fulfils the condition (∂B/∂T)ρ=0 occurs at a particular region of the phase diagram, between 3.4 and 2.4 times the critical density of each liquid. Interestingly, the previously found density ρα is close to ρB, in a similar region of the reduced phase diagram. However, we note that ρB typically decreases to a lesser extent with temperature than ρα. In addition, we have found that ρB(T) behaves in a parallel fashion for the different liquids, showing larger values of ρB as the complexity of the molecules increases. These findings provide a strong basis for developing general equation of state models to describe the behaviour of liquids in the high-pressure regime

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

    OpenAIRE

    Parhi, P. K.

    2013-01-01

    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 strip...

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

    International Nuclear Information System (INIS)

    The first works in this field were realized approximately 25 years ago, when BLOCK et al. reported their studies about carrier-mediated transport (also called pertraction or membrane extraction) of uranium through plasticized membranes with neutral esters derived from phosphoric acid. At this time, the methodical principles of selective pertraction of ionic compounds through so-called bulk liquid membranes containing carriers were known. However, these membranes, similarly as plasticized membranes, have not achieved a broader use. This is probably because bulk liquid membranes are from a technical point of view fairly distant from the idea of a typical membrane system, and plasticized membranes (sometimes also called gel membranes) present great resistance. By the end of the 1960's and at the beginning of the 1970's, LI and CUSSLER worked out the principles for two widely used pertraction techniques, called pertraction through emulsion liquid and supported liquid membranes (ELM and SLM). These two techniques not only have greatest significance in laboratory practice, but they also are interesting for technological aims because of the attainable large phase boundaries, e.g. 103-104 m2/m3. Many ways to arrange membrane systems are described in papers. Recently, the significance of carrier-mediated transport through liquid membranes has grown to have (since 1980) separate section at the International Solvent Extraction Conference. This paper does not deal with mathematical models and the mechanism of pertraction in general, but it gives an overview of results obtained in publications referring to pertraction of two related element groups - actinoids and rare earth elements - using various membrane types. (author) 154 refs

  12. Ionic selectivity of liquid dialkyl phthalate membranes

    International Nuclear Information System (INIS)

    Potentials of liquid dialkyl phthalate membranes have been studied. It is shown that they possess a sufficiently high selectivity to Cs2+, UO22+ ions. The method is suggested to clarify the actual role of softener and presupposed electrode-active addition in film electrodes. It is shown that selectivity of the known in literature uranyl film electrode on the basis of dioctyl sulfoxide (DOSO) is due to the softener-dialkyl phthalate, and not to DOSO, as it was previously considered

  13. Transport of Liquid Phase Organic Solutes in Liquid Crystalline Membranes

    OpenAIRE

    Han, Sangil

    2010-01-01

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

  14. Synthesis and crystal structure of a new N-(2,6-dichlorobenzoyl)-N',N''-bis(pyrrolidinyl)-phosphoric triamide as a carrier and competitive bulk liquid membrane transport of six metal cations

    Czech Academy of Sciences Publication Activity Database

    Khoshnood, R.S.; Pourayoubi, M.; Kasraee, F.; Toghraee, M.; Dušek, Michal; Bereciartua, P.J.

    2014-01-01

    Roč. 88, č. 12 (2014), s. 2146-2156. ISSN 0036-0244 Institutional support: RVO:68378271 Keywords : organic membrane * ionic transport * crystal structure Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.562, year: 2014

  15. Extraction and Transport of Amino Acids Using Kryptofix 5 as Carrier through Liquid Membrane

    OpenAIRE

    Pankaj Raizada; Uma Sharma

    2013-01-01

    The present work explores membrane-mediated extraction and transport studies of amino acids through artificial bulk liquid membrane system with kryptofix 5 as a carrier. The various reaction parameters such as amino acid concentration, carrier concentration, time, pH, and stirring effect were studied to optimize reaction conditions. The stirring of source and receiving phases increased the efficiency of extraction process. Noncyclic receptor kryptofix 5 with five oxyethylene units an...

  16. Performance Evaluation of Organic Emulsion Liquid Membrane on Phenol Removal

    OpenAIRE

    Ng, Yee Sern; Jayakumar, Natesan Subramaniam; Hashim, Mohd Ali

    2010-01-01

    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 ...

  17. Facilitated transport of alkaline and alkaline earth metals through liquid membranes with acidic extractants

    International Nuclear Information System (INIS)

    The removal of radioactive Cs and Sr from the liquid waste of nuclear plants is an important problem for both the defense arid the energy industries. Experiments with bulk liquid membranes and liquid membranes, immobilized on porous support, demonstrated the applicability of these systems for active transport of alkaline cations and Sr from alkaline to acidic solution against the concentration gradient of the metal. The mechanism of transport facilitated by fatty acids for alkali metals, or by di-2-ethylhexyl phosphoric acid for Sr in the presence of Ca and EDTA, corresponds to the open-quotes big carrouselclose quotes model, according to which the carrier is distributed between the membrane and aqueous solutions, where metal/H+- ion exchange takes place. The rate limiting step is the reextraction of Sr from the membrane into the acceptor (acidic) solution and is determined by the diffusion of the protonated carrier from the stripping acidic solution through the corresponding unstirred layer

  18. Extraction and Transport of Amino Acids Using Kryptofix 5 as Carrier through Liquid Membrane

    Directory of Open Access Journals (Sweden)

    Pankaj Raizada

    2013-01-01

    Full Text Available The present work explores membrane-mediated extraction and transport studies of amino acids through artificial bulk liquid membrane system with kryptofix 5 as a carrier. The various reaction parameters such as amino acid concentration, carrier concentration, time, pH, and stirring effect were studied to optimize reaction conditions. The stirring of source and receiving phases increased the efficiency of extraction process. Noncyclic receptor kryptofix 5 with five oxyethylene units and terminal aromatic donor end groups governs its transport and extraction efficiency. The extraction and transport efficiency followed the following trend: valine > alanine > glycine > threonine. Supported liquid membrane (SLM studies were performed using cellulose nitrate, PTFE, eggshell, and onion membranes. The egg shell membrane support proved to be most efficient due to intricate network of water insoluble proteins fibers with very high surface area and homogeneity.

  19. 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 ...

  20. Small intestinal response to 'elemental' and 'complete' liquid feeds in the rat: effect of dietary bulk.

    OpenAIRE

    Maxton, D. G.; Cynk, E U; Thompson, R P

    1987-01-01

    The effect of oral isocaloric feeding on small intestinal structure and function was studied in the rat. The liquid 'elemental' enteral feed Vivonex HN, the liquid 'complete' feed Ensure and the same liquid complete feed with 9% bulk Enrich were compared with solid chow containing 21% bulk (normal rat chow), all given for four weeks. Weight gain was significantly less in the group fed Vivonex HN than that of any other groups. The bulkless Vivonex HN and Ensure increased proximal jejunal mass ...

  1. 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).

  2. High temperature ceramic membrane reactors for coal liquid upgrading

    Energy Technology Data Exchange (ETDEWEB)

    Tsotsis, T.T.

    1992-06-19

    Ceramic membranes are a new class of materials, which have shown promise in a variety of industrial applications. Their mechanical and chemical stability coupled with a wide range of operating temperatures and pressures make them suitable for environments found in coal liquid upgrading. In this project we will evaluate the performance of Sel-Gel alumina membranes in coal liquid upgrading processes under realistic temperature and pressure conditions and investigate the feasibility of using such membranes in a membrane reactor based coal liquid upgrading process. In addition, the development of novel ceramic membranes with enhanced catalytic activity for coal-liquid upgrading applications, such as carbon-coated alumina membranes, will be also investigated.

  3. 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.

  4. SELECTIVE TRANSPORT OF GOLD(Ⅱ) THROUGH THE LIQUID MEMBRANE CONTAINING POLYTHIOETHER OLIGOMER AS CARRIER

    Institute of Scientific and Technical Information of China (English)

    XUYuwu; WANGYing; 等

    1993-01-01

    This paper deals with the transport properties of oligomer of polythioether PSA used as moble carrier in bulk liquid membrane for gold(Ⅲ).It was found that Au(Ⅲ) can be transported by PSA from source phase to receiving phase completely under appropriate conditions and only Au(Ⅲ) can be transferred through the liquid membrane to receiving phase from a mixture of Na(I)-Cu(Ⅱ)-Au(Ⅲ)-Fe(Ⅲ)-Pt(Ⅳ) in the following system:HAuCl4-HCl(aq.)/PSA-ClCH2-CH2Cl/(NH2)2CS-HCl(aq.).The transport rate of Au(Ⅲ) depended on the concentration of carrier,the thickness of liquid membrane,the concentration of Au(Ⅲ) in source phase and the acidity of the media.

  5. High temperature ceramic membrane reactors for coal liquid upgrading

    Energy Technology Data Exchange (ETDEWEB)

    Tsotsis, T.T.

    1992-01-01

    In this project we intend to study a novel process concept, i.e, the use of ceramic membranes reactors in upgrading of coal derived liquids. Membrane reactors have been used in a number of catalytic reaction processes in order to overcome the limitations on conversion imposed by thermodynamic equilibrium. They have, furthermore, the inherent capability for combining reaction and separation in a single step. Thus they offer promise for improving and optimizing yield, selectivity and performance of processes involving complex liquids, as those typically found in coal liquid upgrading. Ceramic membranes are a new class of materials, which have shown promise in a variety of industrial applications. Their mechanical and chemical stability coupled with a wide range of operating temperatures and pressures make them suitable for environments found in coal liquid upgrading. In this project we will evaluate the performance of Sol-Gel alumina membranes in coal liquid upgrading processes under realistic temperature and pressure conditions and investigate the feasibility of using such membranes in a membrane reactor based coal liquid upgrading process. In addition, the development of novel ceramic membranes with enhanced catalytic activity for coal-liquid upgrading applications, such as carbon-coated alumina membranes, will be also investigated.

  6. 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 of the...

  7. 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

  8. Effects of an embedding bulk fluid on phase separation dynamics in a thin liquid film

    OpenAIRE

    Ramachandran, Sanoop; Komura, Shigeyuki; Gompper, Gerhard

    2010-01-01

    Using dissipative particle dynamics simulations, we study the effects of an embedding bulk fluid on the phase separation dynamics in a thin planar liquid film. The domain growth exponent is altered from 2D to 3D behavior upon the addition of a bulk fluid, even though the phase separation occurs in 2D geometry. Correlated diffusion measurements in the film show that the presence of bulk fluid changes the nature of the longitudinal coupling diffusion coefficient from logarithmic to algebraic de...

  9. Carbon Dioxide Separation with Supported Ionic Liquid Membranes

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-04-01

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

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

    International Nuclear Information System (INIS)

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

  11. (Meth)acrylate liquid crystalline polymers for membrane applications

    Czech Academy of Sciences Publication Activity Database

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

    2015-01-01

    Roč. 132, č. 43 (2015), 42694_1-42694_8. ISSN 0021-8995 Institutional support: RVO:61389013 Keywords : copolymers * liquid crystals * membranes Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.768, year: 2014

  12. 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....

  13. Carrier-facilitated transport of plutonium(IV) through tributyl phosphate/dodecane liquid membranes

    International Nuclear Information System (INIS)

    Selective transport of Pu4+ over other long-lived fission product contaminants has been accomplished from aqueous acidic solutions through an organic bulk liquid membrane (BLM) and flat-sheet immobilized liquid membrane (ILM) containing tributyl phosphate (TBP) as the mobile carrier and dodecane as the membrane solvent. Extremely dilute to moderately concentrated plutonium nitrate solutions (10-5 mol dm-3) in about 2 mol dm-3 HNO3 are used as the source phase. With increase in carrier concentration in the organic membrane both, the amount of plutonium that can be extracted into the membrane and the viscosity of the organic solution increases. These opposing effects result in maximum plutonium permeation with about 30% TBP in dodecane while enhanced acidity of the strip side adversely affects the partitioning of the cation into the product side. Among the several aqueous reagents tested, 0.5 mol dm-3 ascorbic acid is found to be the most efficient strippant. The stoichiometry of the Pu4+-TBP complex in the liquid membrane system has been established as Pu(NO3)4.2TBP. The lack of any contamination from even appreciable amounts of possible fission product contaminants is a feature of this novel separation technique. (author). 16 refs., 6 figs., 3 tabs

  14. 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.

  15. Bulk and contact resistances of gas diffusion layers in proton exchange membrane fuel cells

    Science.gov (United States)

    Ye, Donghao; Gauthier, Eric; Benziger, Jay B.; Pan, Mu

    2014-06-01

    A multi-electrode probe is employed to distinguish the bulk and contact resistances of the catalyst layer (CL) and the gas diffusion layer (GDL) with the bipolar plate (BPP). Resistances are compared for Vulcan carbon catalyst layers (CL), carbon paper and carbon cloth GDL materials, and GDLs with microporous layers (MPL). The Vulcan carbon catalyst layer bulk resistance is 100 times greater than the bulk resistance of carbon paper GDL (Toray TG-H-120). Carbon cloth (CCWP) has bulk and contact resistances twice those of carbon paper. Compression of the GDL decreases the GDL contact resistance, but has little effect on the bulk resistance. Treatment of the GDL with polytetrafluoroethylene (PTFE) increases the contact resistance, but has little effect on the bulk resistance. A microporous layer (MPL) added to the GDL decreases the contact resistance, but has little effect on the bulk resistance. An equivalent circuit model shows that for channels less than 1 mm wide the contact resistance is the major source of electronic resistance and is about 10% of the total ohmic resistance associated with the membrane electrode assembly.

  16. Effective Purification of Biogas by a Condensing-Liquid Membrane

    Czech Academy of Sciences Publication Activity Database

    Poloncarzová, Magda; Vejražka, Jiří; Veselý, Václav; Izák, Pavel

    Bratislava : Slovak Society of Chemical Engineering, 2011 - (Markoš, J.), s. 102 ISBN 978-80-227-3503-2. [International Conference of Slovak Society of Chemical Engineering /38./. Tatranské Matliare (SK), 23.05.2011-27.05.2011] Institutional research plan: CEZ:AV0Z40720504 Keywords : membrane * condensing liquid membrane * biogas Subject RIV: CI - Industrial Chemistry, Chemical Engineering

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

    International Nuclear Information System (INIS)

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

  18. Bulk and interfacial liquid water as a transient network.

    Science.gov (United States)

    Jahn, Miriam; Gekle, Stephan

    2015-11-01

    The special macroscopic properties of liquid water stem from its structure as a complex network of molecules connected by hydrogen bonds. While the dynamics of single molecules within this network has been extensively investigated, only little attention has been paid to the closed loops (meshes) of hydrogen-bonded molecules which determine the network topology. Using molecular dynamics simulations we analyze the size, shape, geometrical arrangement, and dynamical stability of loops containing up to 10 hydrogen bonds. We find that six-membered loops in liquid water even at room temperature retain a striking similarity with the well-known structure of ice. Analyzing the network dynamics we find that rings of more than five hydrogen bonds are stabilized compared to a random collection containing the same number of single bonds. We finally show that in the vicinity of hydrophobic and hydrophilic interfaces loops arrange in a preferred orientation. PMID:26651669

  19. 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.

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

    Czech Academy of Sciences Publication Activity Database

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

    2016-01-01

    Roč. 160, FEB 29 (2016), s. 132-135. ISSN 1383-5866 Institutional support: RVO:67985858 Keywords : gas separation * liquid membrane * methane Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 3.091, year: 2014

  1. 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.

  2. Low-temperature heat capacities of confined liquid benzene, implying the behavior of ordinary bulk liquids

    Science.gov (United States)

    Nagoe, A.; Oguni, M.; Fujimori, H.

    2015-11-01

    Isobaric heat capacities C p of benzene confined in silica MCM-41 mesopores with average diameters equal to and smaller than 2.9 nm were measured by precise adiabatic calorimetry. The confined benzene samples revealed no thermal anomaly due to crystallization/fusion and vitrified at low temperatures. The C p curves displayed a hump and a considerably quick decrease on the low-temperature side of the hump as the pore diameter increased. The enthalpy-relaxation effects observed on intermittent heating showed that the anomaly of the C p hump and quick decrease is not assigned to a glass transition. The bend in the temperature dependence of density reported previously was interpreted as corresponding to the quick decrease in C p . We concluded that the anomalous C p and density behaviors originated from the ordering/excitation in the configurational state, close to the ground state, of confined molecular aggregate and proposed a scenario that explains the general C p curves of ordinary bulk supercooled liquids in equilibrium at low temperatures below the glass-transition temperatures.

  3. 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.

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

    International Nuclear Information System (INIS)

    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 Tg. 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

  5. Boiling of the Interface between Two Immiscible Liquids below the Bulk Boiling Temperatures of Both Components

    OpenAIRE

    Pimenova, Anastasiya V.; Goldobin, Denis S.

    2014-01-01

    We consider the problem of boiling of the direct contact of two immiscible liquids. An intense vapour formation at such a direct contact is possible below the bulk boiling points of both components, meaning an effective decrease of the boiling temperature of the system. Although the phenomenon is known in science and widely employed in technology, the direct contact boiling process was thoroughly studied (both experimentally and theoretically) only for the case where one of liquids is becomin...

  6. Immiscible organic liquid recovery using unconfined membranes

    International Nuclear Information System (INIS)

    Hydrophobic hollow fiber microporous membranes have been characterized and applied to the problem of separating and recovering low density hydrocarbons from water surfaces. The merits of hollow fiber technology as applied to this problem are discussed and a model for predicting recovery performance is shown to be accurate. Future work on a recovery device using this technology is outlined and potential applications are identified

  7. Application of Supported Ionic Liquid Membranes for Biogas Separation.

    Czech Academy of Sciences Publication Activity Database

    Sedláková, Zuzana; Kárászová, Magda; Vejražka, Jiří; Izák, Pavel

    Pardubice: Czech Membrane Platform, 2016 - (Palatý, Z.), s. 80 ISBN 978-80-904517-6-6. [PERMEA and MELPRO Conference 2016. Praha (CZ), 15.05.2016-19.05.2016] R&D Projects: GA ČR GA14-12695S Institutional support: RVO:67985858 Keywords : ionic liquid membrane * biogas upgrading * carbon dioxide removal Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  8. Rejuvenation of Spent Media via Supported Emulsion Liquid Membranes

    Science.gov (United States)

    Wiencek, John M.

    2002-01-01

    The overall goal of this project is to maximize the reuseability of spent fermentation media. Supported emulsion liquid membrane separation, a highly efficient extraction technique, is used to remove inhibitory byproducts during fermentation; thus, improving the yield while reducing the need for fresh water. The key objectives of this study are: Develop an emulsion liquid membrane system targeting low molecular weight organic acids which has minimal toxicity on a variety of microbial systems; Conduct mass transfer studies to allow proper modeling and design of a supported emulsion liquid membrane system; Investigate the effect of gravity on emulsion coalescence within the membrane unit; Access the effect of water re-use on fermentation yields in a model microbial system; Develop a perfusion-type fermentor utilizing a supported emulsion liquid membrane system to control inhibitory fermentation byproducts; Work for the coming year will focus on the determination of toxicity of various solvents, selection of the emulsifying agents, as well as characterizing the mass transfer of hollow-fiber contactors.

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

    Science.gov (United States)

    Zeh, Matthew; Wickramanayake, Shan; Hopkinson, David

    2016-01-01

    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. PMID:27023620

  10. Failure Mechanisms of Hollow Fiber Supported Ionic Liquid Membranes

    Directory of Open Access Journals (Sweden)

    Matthew Zeh

    2016-03-01

    Full Text Available 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(trifluoromethylsulfonylimide ([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.

  11. Physics of transduction in ionic liquid-swollen Nafion membranes

    Science.gov (United States)

    Bennett, Matthew; Leo, Donald

    2006-03-01

    Ionic polymer transducers are a class of electroactive polymers that are able to generate large strains (1-5%) in response to low voltage inputs (1-5 V). Additionally, these materials generate electrical charge in response to mechanical strain and are therefore able to operate as soft, distributed sensors. Traditionally, ionic polymer transducers have been limited in their application by their hydration dependence. This work seeks to overcome this limitation by replacing the water with an ionic liquid. Ionic liquids are molten salts that exhibit very high thermal and electrochemical stability while also possessing high ionic conductivity. Results have shown that an ionic liquid-swollen ionic polymer transducer can operate for more than 250,000 cycles in air as compared to about 2,000 cycles for a water-swollen transducer. The current work examines the mechanisms of transduction in ionic liquid-swollen transducers based on Nafion polymer membranes. Specifically, the morphology and relevant ion associations within these membranes are investigated by the use of small-angle X-ray scattering (SAXS), Fourier transform infrared spectroscopy (FTIR), and nuclear magnetic resonance spectroscopy (NMR). These results reveal that the ionic liquid interacts with the membrane in much the same way that water does, and that the counterions of the Nafion polymer are the primary charge carriers. The results of these analyses are compared to the macroscopic transduction behavior in order to develop a model of the charge transport mechanism responsible for electromechanical coupling in these membranes.

  12. Boron Removal in Radioactive Liquid Waste by Forward Osmosis Membrane

    International Nuclear Information System (INIS)

    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

  13. 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.

  14. 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

  15. 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. PMID:18093731

  16. Electromechanical Transduction in Ionic Liquid-Swollen Nafion Membranes

    OpenAIRE

    Bennett, Matthew Damon

    2005-01-01

    Traditionally, water has been used as the diluent for ionomeric polymer transducers. The water mobilizes the counterions within the polymer and allows electromechanical transduction to occur. However, these water-swollen devices have limited stability when operated in a non-aqueous environment. In this work, ionic liquids are demonstrated as viable diluents for ionomeric polymer transducers based on Nafion membranes. Ionic liquids are molten salts that are highly thermally stable and have...

  17. Membrane technologies for processing of liquid radioactive waste

    International Nuclear Information System (INIS)

    Reverse osmosis is used were complete rejection of all dissolved compounds is required; it needs pre-treatment of the waste by microfiltration, ultrafiltration or other conventional technique to avoid the membrane blockage by colloids and suspensions. Recently the nanofiltration membranes are often used to separate monovalent ions from multivalent. Ultrafiltration apart of pre-treatment stage is used to separate colloids, which usually are formed by compounds of 54Mn, 55Fe. 60Co and 125Sb. Microfiltration found application for solid wastes dewatering before final disposal. A novel technology is membrane distillation proposed by researches from INCT for concentration of liquid radioactive waste. (author)

  18. Bulk-Micromachined Optical Filter Based on Guided-Mode Resonance in Silicon-Nitride Membrane

    Science.gov (United States)

    Hsu, Che-Lung; Liu, Yung-Chih; Wang, Chih-Ming; Wu, Mount-Learn; Tsai, Ya-Lun; Chou, Yue-Hong; Lee, Chien-Chieh; Chang, Jenq-Yang

    2006-04-01

    In this paper, a single-layer guided-mode resonance (GMR) filter based on a free-standing silicon-nitride membrane suspended on a silicon substrate is achieved by using bulk-micromachining technology. Both of grating and waveguide structures without a lower-cladding layer, i.e., substrate, are fabricated simultaneously on a silicon-nitride membrane. The device can be used as a transmission bandstop filter with the advantages of simple structure, high efficiency, and feasibility to integrate with other optoelectronic elements into a microsystem chip. The design consideration, fabrication procedures, and measured spectral response are shown in this paper. Moreover, by stacking two proposed devices, Δλ of the stopband at a transmission below 10% is 5.06 nm.

  19. Preconcentration in micro-electromembrane extraction across free liquid membranes

    Czech Academy of Sciences Publication Activity Database

    Kubáň, Pavel; Boček, Petr

    2014-01-01

    Roč. 848, Oct (2014), s. 43-50. ISSN 0003-2670 R&D Projects: GA ČR(CZ) GA13-05762S Institutional support: RVO:68081715 Keywords : free liquid membranes * micro-electromembrane extraction * preconcentration Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 4.513, year: 2014

  20. Hollow fibre supported liquid membrane based separations of actinides

    International Nuclear Information System (INIS)

    Renaissance in nuclear energy is poised to make a significant contribution to the diversification of clean energy resources and to reduce the burden of CO2 in atmosphere. Its sustainability lies in using nature's mineral resources in an efficient and environmentally friendly way. One of the major challenges in the nuclear energy programme has, however, been the management of radioactive waste in a manner which allays apprehensions about its adverse impact on the environment. Innovative approaches are being devised internationally to treat spent nuclear fuel as a source of valuables. Separation of long-lived radionuclides such as actinides and fission products from high level radioactive waste is a challenging task for the chemists working on the reprocessing and waste management processes involved at the tail end of nuclear fuel cycle. Amongst the various separation techniques, liquid membrane based separation methods are becoming increasingly popular due to factors such as ligand economy, high efficiency and low power consumption. Techniques such as emulsion liquid membrane and hollow fibre based non-dispersive solvent extraction methods are reported to be more efficient than the solvent extraction based separation methods which have limitations of emulsion/third phase or crud formation. In the present article, an attempt has been made to review the work carried out internationally as well as in the author's laboratory on liquid membrane based actinides separations during last few years with a particular focus on the use of hollow fibre supported liquid membranes. (author)

  1. Small intestinal response to 'elemental' and 'complete' liquid feeds in the rat: effect of dietary bulk.

    Science.gov (United States)

    Maxton, D G; Cynk, E U; Thompson, R P

    1987-06-01

    The effect of oral isocaloric feeding on small intestinal structure and function was studied in the rat. The liquid 'elemental' enteral feed Vivonex HN, the liquid 'complete' feed Ensure and the same liquid complete feed with 9% bulk Enrich were compared with solid chow containing 21% bulk (normal rat chow), all given for four weeks. Weight gain was significantly less in the group fed Vivonex HN than that of any other groups. The bulkless Vivonex HN and Ensure increased proximal jejunal mass compared to Enrich with 9% bulk or to normal rat chow. Jejunal mucosal DNA and protein levels also tended to be higher in Ensure and Vivonex HN fed animals, as was jejunal sugar absorption. In the terminal ileum, however, total weight was decreased by both elemental and complete feeds with and without bulk, but particularly by the elemental diet. Bulkless feeds therefore increase jejunal and reduce terminal ileal mass. The striking atrophy of the terminal ileum produced by the elemental diet may be important for its efficacy in treating inflammatory bowel disease. PMID:3040541

  2. Removal of Radioactive Pollutants by Liquid Emulsion Membrane From Liquid Waste

    International Nuclear Information System (INIS)

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

  3. Bulk volumetric liquid water content in a seasonal snowpack: modeling its dynamics in different climatic conditions

    Science.gov (United States)

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

    2015-12-01

    We focus on the dynamics of volumetric liquid water content in seasonal snow covers. This is a key variable describing the fate of snowpacks during the melting season. However, its measurement and/or prediction by means of models at high spatial and temporal resolutions is still difficult due to both practical and theoretical reasons. To overcome these limitations in operational applications, we test the capability of a one-dimensional model to predict the dynamics of bulk volumetric liquid water content during a snow season. Multi-year data collected in three experimental sites in Japan are used as an evaluation. These sites are subjected to different climatic conditions. The model requires the calibration of one or two parameters, according to the degree of detail used. Either a simple temperature-index or a coupled melt-freeze temperature-index approach are considered to predict melting and/or melt-freeze dynamics of liquid water. Results show that, if melt-freeze dynamics are modeled, median absolute differences between data and predictions are consistently lower than 1 vol% at the sites where data of liquid water content are available. In addition, we find also that the model predicts correctly a dry condition in 80% of the observed cases at a site where calibration data are scarce. At the same site, observed isothermal conditions of the snow cover at 0 °C correspond to predictions of bulk volumetric liquid water content that are greater than 0.

  4. Cu-based bulk amorphous alloy with larger glass-forming ability and supercooled liquid region

    Energy Technology Data Exchange (ETDEWEB)

    Fu, H.M. [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); School of Engineering, University of Queensland, St. Lucia, Qld 4072 (Australia)], E-mail: waterdrophmfu@hotmail.com; Zhang, H.F. [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Wang, H. [Faculty of Engineering and Surveying, University of Southern Queensland, Toowoomba, Qld 4350 (Australia); Hu, Z.Q. [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China)

    2008-06-30

    The glassy rod with a maximum sample thickness of 11 mm and larger supercooled liquid region of 108 K was successfully fabricated when substituting Cu with minor amount of Ag in the Cu-Zr-Al-Gd alloy system. The value of {gamma} reaches a maximum of 0.418 for the Cu{sub 45.5}Zr{sub 45}Al{sub 7}Gd{sub 2}Ag{sub 0.5} bulk metallic glass (BMG) alloy. The high glass-forming ability (GFA) and larger supercooled liquid region are discussed from atomic size, negative mixing heat among constituent elements and thermodynamics.

  5. Feasibility of Surfactant-Free Supported Emulsion Liquid Membrane Extraction

    Science.gov (United States)

    Hu, Shih-Yao B.; Li, Jin; Wiencek, John M.

    2001-01-01

    Supported emulsion liquid membrane (SELM) is an effective means to conduct liquid-liquid extraction. SELM extraction is particularly attractive for separation tasks in the microgravity environment where density difference between the solvent and the internal phase of the emulsion is inconsequential and a stable dispersion can be maintained without surfactant. In this research, dispersed two-phase flow in SELM extraction is modeled using the Lagrangian method. The results show that SELM extraction process in the microgravity environment can be simulated on earth by matching the density of the solvent and the stripping phase. Feasibility of surfactant-free SELM (SFSELM) extraction is assessed by studying the coalescence behavior of the internal phase in the absence of the surfactant. Although the contacting area between the solvent and the internal phase in SFSELM extraction is significantly less than the area provided by regular emulsion due to drop coalescence, it is comparable to the area provided by a typical hollow-fiber membrane. Thus, the stripping process is highly unlikely to become the rate-limiting step in SFSELM extraction. SFSELM remains an effective way to achieve simultaneous extraction and stripping and is able to eliminate the equilibrium limitation in the typical solvent extraction processes. The SFSELM design is similar to the supported liquid membrane design in some aspects.

  6. Effect of a solid/liquid interface on bulk solution structures under flow

    International Nuclear Information System (INIS)

    It has been known for some time that a shear field can impart enough energy to a liquid system for it to exhibit a phase change. Not as well appreciated is the fact that non Newtonian solutions can be driven into a quasi phase separation due to the vastly different shear rates between the bulk and near surface regions. Using a variety of scattering techniques the authors have probed the interfacial and near surface region of a system of wormlike colloidal particles under flow separately from the bulk. They find that the hexagonal phase which forms under flow near the surface, does not persist into the bulk. They also present data showing substantial differences in the kinetics of alignment and relaxation of the two phases

  7. Development of Membrane Materials for Gas-liquid Membrane Contactors for CO2 Capture from Natural Gas

    OpenAIRE

    Tomasa, Tina

    2013-01-01

    In this work, membrane materials are developed with the purpose to be used in a gas-liquid membrane contactor for CO2 capture from natural gas. The amine, methyl diethanolamine (MDEA), is to be used in the liquid phase as the absorbent. This requires a hydrophobic membrane material with high permeabilities and good compatibility with the absorption liquid.Poly(1-trimethysilyl-1-propyne) (PTMSP) is a glassy, high free volume polymer, which achieves the highest gas permeabilities of al known po...

  8. Development of Membrane Materials for Gas-liquid Membrane Contactors for CO2 Capture from Natural Gas

    OpenAIRE

    Tomasa, Tina

    2013-01-01

    In this work, membrane materials are developed with the purpose to be used in a gas-liquid membrane contactor for CO2 capture from natural gas. The amine, methyl diethanolamine (MDEA), is to be used in the liquid phase as the absorbent. This requires a hydrophobic membrane material with high permeabilities and good compatibility with the absorption liquid.Poly(1-trimethysilyl-1-propyne) (PTMSP) is a glassy, high free volume polymer, which achieves the highest gas permeabilities of al known po...

  9. 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

  10. High temperature ceramic membrane reactors for coal liquid upgrading

    Energy Technology Data Exchange (ETDEWEB)

    Tsotsis, T.T.

    1992-01-01

    In this project we will study a novel process concept, i.e., the use of ceramic membrane reactors in upgrading of coal model compounds and coal derived liquids. In general terms, the USC research team is responsible for constructing and operating the membrane reactor apparatus and for testing various inorganic membranes for the upgrading of coal derived asphaltenes and coal model compounds. The USC effort will involve the principal investigator of this project and two graduate research assistants. The ALCOA team is responsible for the preparation of the inorganic membranes, for construction and testing of the ceramic membrane modules, and for measurement of their transport properties. The ALCOA research effort will involve Dr. Paul K. T. Liu, who is the project manager of the ALCOA research team, an engineer and a technician. UNOCAL's contribution will be limited to overall technical assistance in catalyst preparation and the operation of the laboratory upgrading membrane reactor and for analytical back-up and expertise in oil analysis and materials characterization. UNOCAL is a no-cost contractor but will be involved in all aspects of the project, as deemed appropriate.

  11. Use of liquid membranes for treatment of nuclear wastes

    International Nuclear Information System (INIS)

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

  12. Research News: Emulsion Liquid Membrane Extraction in a Hollow-Fiber Contactor

    Science.gov (United States)

    Wiencek, John M.; Hu, Shih-Yao

    2000-01-01

    This article describes how ELMs (emulsion liquid membranes) can be used for extraction. The article addresses the disadvantages of ELM extraction in a stirred contactor, and the advantages of SELMs (supported emulsion liquid membranes). The introduction of the article provides background information on liquid-liquid solvent extraction and dispersion-free solvent extraction.

  13. Transport of strontium cation through hollow fiber supported liquid membranes

    International Nuclear Information System (INIS)

    Transport of strontium through supported hollow fiber dichlorobenzene liquid membranes has been studied. The possible mechanism of strontium transport with 18-crown-6 ether as a carrier and picrate as co-counter-ion as well as the construction of a pertraction device with on-line radiometric detection of strontium using 85Sr tracer is described. Preliminary results of strontium pertraction in a recycling and one-pass mode with different concentrations of crown are shown. (author) 11 refs.; 5 figs

  14. Ionic Liquid Membranes for Carbon Dioxide-Methane Separation

    Czech Academy of Sciences Publication Activity Database

    Uchytil, Petr; Schauer, Jan; Pientka, Zbyněk; Petričkovič, Roman; Suen, S.-Y.

    2010, s. 1. ISBN N. [AMS6/IMSTEC10. Sydney (AU), 22.11.2010-25.11.2010] R&D Projects: GA ČR GA104/09/1165; GA ČR GCP106/10/J038 Institutional research plan: CEZ:AV0Z40720504; CEZ:AV0Z40500505 Keywords : carbon dioxide * methane * ionic liquid membranes Subject RIV: CB - Analytical Chemistry, Separation

  15. Effect of Viscosity on the Microformability of Bulk Amorphous Alloy in Supercooled Liquid Region

    International Nuclear Information System (INIS)

    Previously published results have shown that viscosity greatly influences on the deformation behavior of the bulk amorphous alloy in supercooled liquid region during microforming process. And viscosity is proved to be a component of the evaluation index which indicating microformability. Based on the fluid flow theory and assumptions, bulk amorphous alloy can be regarded as the viscous materials with a certain viscosity. It is helpful to understand how the viscosity plays an important role in viscous materials with various viscosities by numerical simulation on the process. Analysis is carried out by linear state equation in FEM with other three materials, water, lubricant oil and polymer melt, whose viscosities are different obviously. The depths of the materials flow into the U-shaped groove during the microimprinting process are compared in this paper. The result shows that the deformation is quite different when surface tension effect is not considered in the case. With the lowest viscosity, water can reach the bottom of micro groove in a very short time. Lubricant oil and polymer melt slower than it. Moreover bulk amorphous alloys in supercooled liquid state just flow into the groove slightly. Among the alloys of different systems including Pd-, Mg- and Zr-based alloy, Pd-based alloy ranks largest in the depth. Mg-based alloy is the second. And Zr-based alloy is the third. Further more the rank order of the viscosities of the alloys is Pd-, Mg- and Zr-based. It agrees well with the results of calculation. Therefore viscosity plays an important role in the microforming of the bulk amorphous alloy in the supercooled liquid state.

  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. Selection of polymer solid supports for supported liquid membrane applications

    International Nuclear Information System (INIS)

    The role of polymer support selection upon the performance and stability of a supported liquid membrane(SLM) has been evaluated in detail. Permeation experiments are carried out batch wise in a simple twin stirred cells. Several solid supports such as polytetrafluroethylene (TE-35, TE-36, TE-37), polypropylene (HF-PP), cellulose nitrate (BA-S-83) of different pore sizes and varying thickness are tested. Dicyclohexano-18-crown-6 (DC18C6) in toluene has been employed as mobile carrier in permeation of plutonium (IV) nitrate across SLM. Selectivity of plutonium transport from fission product contaminants such as 137Cs. 103Ru and 144Ce is found to be lesser with large pore size (0.45 μm) support. Chemical stability of these hydrophobic polymer membranes against organic solvents and nitric acid is evaluated. Polytetrafluroethylene supports like TE-35, TE-36, TE-37 and polypropylene HF-PP membranes have not shown any marked deterioration but cellulose nitrate membrane such as BA-S-83 is attacked by organic solvent. Such deleterious effects have been confirmed by the scanning electron microscopy which revealed that pore structure becomes completely blocked. Radiolytic stability of these polymers is also tested by irradiating them up to 3 Mrads using 60Co irradiator. No serious damage due to radiation is observed as micrographs have shown undisturbed network of polymer structure even after the irradiation. Of the different polymer supports tested, both TE-35 and HF-PP thin-film solid membranes prove to be quite suitable for SLM purposes as their optimum pore size, good physical and chemical stability including radiation stability render them relatively more useful for varied applications in liquid membranes. (author). 5 refs., 3 figs., 3 tabs

  18. Controlled Bulk Properties of Composite Polymeric Solutions for Extensive Structural Order of Honeycomb Polysulfone Membranes.

    Science.gov (United States)

    Gugliuzza, Annarosa; Perrotta, Maria Luisa; Drioli, Enrico

    2016-01-01

    This work provides additional insights into the identification of operating conditions necessary to overcome a current limitation to the scale-up of the breath figure method, which is regarded as an outstanding manufacturing approach for structurally ordered porous films. The major restriction concerns, indeed, uncontrolled touching droplets at the boundary. Herein, the bulk of polymeric solutions are properly managed to generate honeycomb membranes with a long-range structurally ordered texture. Water uptake and dynamics are explored as chemical environments are changed with the intent to modify the hydrophilic/hydrophobic balance and local water floatation. In this context, a model surfactant such as the polyoxyethylene sorbitan monolaurate is used in combination with alcohols at different chain length extents and a traditional polymer such as the polyethersufone. Changes in the interfacial tension and kinematic viscosity taking place in the bulk of composite solutions are explored and examined in relation to competitive droplet nucleation and growth rate. As a result, extensive structurally ordered honeycomb textures are obtained with the rising content of the surfactant while a broad range of well-sized pores is targeted as a function of the hydrophilic-hydrophobic balance and viscosity of the composite polymeric mixture. The experimental findings confirm the consistency of the approach and are expected to give propulsion to the commercially production of breath figures films shortly. PMID:27196938

  19. Recent approach in treatment of liquid radioactive waste: membrane methods

    International Nuclear Information System (INIS)

    Full text: The fuel cycle produces different types of radioactive waste. Radioactive waste is also generated during production and application of radioisotopes, as well as during processing of raw materials containing naturally occurring radioactive isotopes. All those wastes have to be treated and conditioned before safe storage or disposal to protect the human health and natural environment. The management of radioactive waste has to be reached with reasonable cost by implementing appropriate technologies. The processing requirements depend on the level of radioactivity and chemical and physical properties of the waste streams. Various methods are used to treat aqueous radioactive wastes, including evaporation, chemical precipitation and ion exchange, as well as less developed solvent extraction, biotechnological processes and membrane methods. Although membrane processes are still considered as novel technologies in the field of radioactive waste treatment, many applications in nuclear centres and laboratories around the world are reported. At the Department of Nuclear Methods of Process Engineering, Institute of Nuclear Chemistry and Technology, for many years membrane techniques are studied and considered as a possible application in radioactive wastes processing field. After some years of research reverse osmosis was applied at Institute of Atomic Energy (Department of Radioactive Waste Treatment) processing the radioactive wastes from all of Poland. The 3-stage RO plant supplements the existing waste processing system based on evaporator giving the possibility of initial concentration of liquid waste or final polishing of the condensate after evaporation. Intensive studies on ultrafiltration (UF) enhanced by sorption on different sorbents or complexation with chelating polymers are carried on. The ceramic membranes made from alumina, titania and zirconia are used in experiments. Such membranes show high chemical, temperature and radiation resistance. They

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

    Czech Academy of Sciences Publication Activity Database

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

    2014-01-01

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

  1. Enhancement of mechanical strength in Y-Ba-Cu-O bulk superconductor through liquid binder addition

    International Nuclear Information System (INIS)

    We studied the effects of the binder addition on the green compacts. We studied the superconducting properties of bulk Y-Ba-Cu-O superconductors. The mechanical properties of the green compacts with binder addition were characterized with the compression tests. We could produce bulk Y-Ba-Cu-O superconductors with binder additions. We have studied the effects of the liquid binder (polyvinyl alcohol) addition (0-10 wt%) on the mechanical properties of the green compacts and also on the superconducting properties of bulk Y-Ba-Cu-O superconductors of 20 mm diameter produced with the top-seeded melt growth (TSMG) process. The mechanical properties of the green compacts with binder addition were characterized with the compression tests, which revealed that mechanical strength increased dramatically with increasing the amount of the binder addition. The binder-added green compacts were then subjected to the TSMG process and oxygen annealing. The trapped field measurements showed that we could produce single-grain bulk Y-Ba-Cu-O samples with binder additions up to 8 wt% without any deterioration in the superconducting properties.

  2. 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

  3. Two-dimensional materials for novel liquid separation membranes.

    Science.gov (United States)

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

    2016-08-19

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

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

    International Nuclear Information System (INIS)

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

  5. 49 CFR 173.243 - Bulk packaging for certain high hazard liquids and dual hazard materials which pose a moderate...

    Science.gov (United States)

    2010-10-01

    ... conforming to 46 CFR part 64 with design pressure of at least 172.4 kPa (25 psig) are authorized. Unless... 49 Transportation 2 2010-10-01 2010-10-01 false Bulk packaging for certain high hazard liquids and... Packaging for Hazardous Materials Other Than Class 1 and Class 7 § 173.243 Bulk packaging for certain...

  6. C. elegans uses Liquid-Liquid Demixing for the Assembly of Non-Membrane-Bound Compartments

    Science.gov (United States)

    Weber, Christoph A.; Juelicher, Frank; Diaz Delgadillo, Andres Felipe; Jawerth, Louise; Hyman, Anthony A.; Department Biological Physics Team; Hyman Lab Collaboration

    2015-03-01

    P granules are liquid cytoplasmic RNA/Protein condensates known to determine the germ lineage in Caenorhabditis elegans. They resemble striking similarities with liquid droplets, such as dripping, shearing and wetting. Assuming that P granules are liquid-like we consider how they form in the crowded cytoplasm. Using confocal and light-sheet microscopy, P granule formation in-vivo and in-vitro is shown to share all hallmarks with a liquid-liquid phase-separation. Specifically, demixing is determined by temperature and concentration, the droplet formation is reversible with respect to temperature quenches and there is evidence for droplet growth due to coalescence and Ostwald-ripening. Liquid-liquid demixing in-vivo breaks the paradigmatic view that a molecular machinery is necessary to build up organelles through complex biological pathways. Instead we propose that P granules form following a Flory-Huggins model. Liquid-liquid demixing could also serve as a mechanism for the assembly of non-membrane-bound compartments in other living organisms.

  7. Penicillin G extraction from simulated media by emulsion liquid membrane

    Directory of Open Access Journals (Sweden)

    Ramazani Kalhor R.

    2007-04-01

    Full Text Available Penicillin G extraction by an emulsion liquid membrane was studied under various operational conditions in a batch system. Span 80 (sorbitan monooleate, TOA (Trioctylamine and a mixture of n-butyl acetate and paraffin were used as surfactant, carrier and diluent, respectively. The effects of stirrer speed, volume ratio of membrane to external phases, initial penicillin G concentration, pH and buffer concentration in the external phase, sodium carbonate concentration in the internal phase, surfactant, volume ratio of diluents and carriers on the extraction rate were examined. Extraction rate was nearly 95% and a concentration greater than 12.67 times of the initial concentration of penicillin G in the external phase was obtained in the internal phase. The pH of external phase, containing a basic salt was theoretically calculated by the amount of penicillin G which was transported in the internal phase. The calculated results agreed well with the experimental data and extraction of penicillin G was successfully performed by the emulsion liquid membrane process through adjustment of the pH of both internal and external phases to an optimum values.

  8. Cleaning of liquid LLW from decontamination processes using semipermeable membranes

    International Nuclear Information System (INIS)

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

  9. 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.

  10. Grafting of nitrogen containing monomers onto poly(ethylene-alt-tetrafluoroethylene) films by bulk polymerization for proton exchange membranes

    International Nuclear Information System (INIS)

    Bulk polymerization is suggested as an alternative to solution polymerization to graft N-containing monomers onto poly(ethylene-alt-tetrafluoroethylene) films to produce highly conductive membranes. Among the tested monomers, 4-vinyl pyridine was found as the most reactive monomer giving grafting levels (%GL) >120 % compared with %GL <45 % previously reported under similar conditions. Doping grafted films with H3PO4 converted them to membranes with enhanced water swellability but their conductivity values were at the same order of magnitude of membranes prepared by solution polymerization. These results demonstrate the importance of having both high grafting levels and homogeneous distribution of grafting throughout the base polymer. (author)

  11. Evaluation of nanofiltration membranes for treatment of liquid radioactive waste

    International Nuclear Information System (INIS)

    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 (UF6) to uranium dioxide (UO2) in the cycle of nuclear fuel. This waste contains about 7.0 mg L-1 of uranium and cannot be discarded to the environment without an adequate treatment. In static tests membrane samples were immersed in the waste for 24 to 5000 h. Their transport properties (hydraulic permeability, permeate flux, sulfate and chloride ions rejection) were evaluated before and after immersion in the waste using a permeation flux front system under 0.5 MPa. The selective layer (polyamide) was characterized by zeta potential, contact angle, scanning electron microscopy for field emission, atomic force microscopy, infrared spectroscopy, x-ray fluorescence and thermogravimetric analysis before and after static tests. In dynamic tests the waste was permeated under 0.5 MPa, and the membranes showed rejection to uranium above 85% were obtained. The short-term static tests (24-72 h) showed that the selective layer and surface charge of the membranes were not chemical changed, according infrared spectra data. After 5000 h a coating layer was released from the membranes, poly(vinyl alcohol), PVA. After this loss the rejection for uranium decreased. Permeation and concentration of the waste were carried out in permeation flux tangential system under 1.5 MPa. The rejection of uranium was around 90% for permeation tests. In concentration tests the permeated was collected continuously until about 80% reduction of the feed volume. The rejection of uranium was of the 97%. The nanofiltration membranes tested were efficient to concentrate the uranium from the waste. (author)

  12. Study of ion separation through solid-supported liquid membrane

    International Nuclear Information System (INIS)

    In this study, a theory was developed and validated for predicting the uranium flux through the solid-supported liquid membrane as a function of PH on the feed side of membrane, carrier concentration in the solvent, and content of uranium in the feed solution. The experimental results showed a good quantitative agreement with the predicted results by the theory. As a result, it was found that the major uranium complexes are formed by the reaction of uramine with both (UO2(SO4)22+) and (UO2(SO4)34+). The principal findings in this study can be summerized as follows: 1)At near PH 1.3, the flux reached a maximum value. 2)The uranium flux increases with increasing the content of alumine 336 up to 30 volume percent, and then decreases again above this concentration. 3)The flux increases sharply with uranium concentration up to 1 g-u/l. (Author)

  13. Study on removal of cadmium by hybrid liquid membrane process

    International Nuclear Information System (INIS)

    Removal of cadmium as a hazardous heavy metal is studied by applying a new design of hybrid cell for liquid membrane process. Tri-iso-octyl amine (TIOA) is used as the carrier in the organic phase. The concentration of cadmium in the samples is measured by atomic absorption spectroscopy. The effect of various parameters including type of supporting membrane, pH of feed and stripping phases, initial concentration of cadmium, carrier concentration, solvent nature, and also organic film resistance on mass transfer rate and removal efficiency are studied. The effect of temperature on mass transfer flux is studied by proposing a prediction model. The optimum carrier concentration is found to be about 0.05 M. The appropriate values of pH for feed and stripping phases are about 3 and 13, respectively.

  14. Isothermal internal friction behaviour of a Zr based bulk metallic glass with large supercooled liquid region

    International Nuclear Information System (INIS)

    In this paper, the internal friction behaviour of Zr-Ti-Cu-Ni-Be bulk metallic glass (BMG) containing 2 at% Fe at elevated temperatures has been studied in isothermal dynamic mechanical analysis experiments. The experiments lead to the determination of metastable equilibrium internal friction Qe-1, as a function of temperature, which can be well described by the Maxwell model with viscosity, η(T), following a Vogel-Fulcher-Tammann (VFT) relation or Arrehnius law. Comparison with the Zr-Ti-Cu-Ni-Be glass-forming liquid shows that a small addition of Fe results in a stronger liquid behaviour of the alloy, exhibiting a higher strength parameter as well as lower VFT temperature and therefore correlates better glass forming ability and thermal stability. From the isothermal internal friction data, the activation energies for viscous flow and primary crystallization of the Zr based supercooled metallic liquid are also derived. It is found that the former is comparable to the activation energy controlling the diffusion process of atoms, e.g. the Ni element of medium size and higher mobility among the components of this alloy, while the latter to that of atoms, e.g. the Ti element of larger size and lower mobility. Thus, it is proposed that both isothermal viscous flow and primary crystallization of the alloy in the supercooleld liquid region are atom diffusion-controlled processes. However, the dominating atomic species are different from each other in the multicomponent Zr based BMG

  15. Cone-shaped membrane liquid phase micro extraction

    International Nuclear Information System (INIS)

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

  16. 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.

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

    International Nuclear Information System (INIS)

    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∗ ∼ 315 ± 5 K, was spotted at T∗ ∼ 283 K and T∗ ∼ 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 mechanisms of the

  18. Permeation of europium through immobilised supported liquid membrane

    International Nuclear Information System (INIS)

    The transport of europium through a porous supported liquid membrane (SLM) containing PC-88A (EHPNA) and Versatic 10 (VA 10) as immobilised carriers has been carried out. The results demonstrated that transport increases with increasing stirring speed, and reaches a constant value beyond a certain rotation speed. The permeability coefficient increases with the increase in carrier concentration in a certain range. The dependence of permeabilities on the pH of both the source and receiving solutions have been explored. The permeability coefficient has been calculated by taking into account the mass balance. The effects of complexing agents such as succinic, malonic and citric acid on permeability coefficient of europium has been investigated. Under similar experimental conditions the effect of complexing agents on permeation of europium has been found as: citric acid>succinic acid>malonic acid. Permeating coefficient of europium has been found greater with PC-88A in comparison with that of Versatic 10. The effect of complexing agents used in receiving phase has been explored. The mechanism of transport of europium in supported liquid membrane has been suggested. The developed methods have been used for the exploration of its utility for synthetic samples. (author). 19 refs., 11 figs., 1 tab

  19. 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.

  20. Pertraction of Penicillin G in Hollow Fiber Contained Liquid Membranes

    International Nuclear Information System (INIS)

    Pertraction of Penicillin G in Hollow Fiber Contained Liquid Membranes was investigated in a system consisting of 2 Liqui Cel 106 modules from Hoechst Celanese. The flux of Pen G depended upon the content of n-octanol and of Amberlite LA2 in kerosene used as a membrane phase. During the pertraction of Pen G in HFCLM system the pH difference between the both buffered aqueous phases diminished proportionally to the contact time with the membrane phase. The flux of citric acid used as a buffer component in the feed phase attained 11.8 mM/m2 x h and was comparable with the flux of Pen G equal to 18.4 mM/m2 x h. In order to eliminate the undesired transport of citric acid, CO2 was used as a volatile buffer component. Although the pH values were stabilised in the range of 5.47 and 7.45 in the feed and strip phase, respectively, the achieved Pen G flux was significantly lower. (author)

  1. 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.

  2. Direct coupling of supported liquid membranes to capillary electrophoresis for analysis of complex samples: A tutorial

    OpenAIRE

    Kubáň, P. (Pavel); Boček, P. (Petr)

    2013-01-01

    This tutorial provides an overview of direct coupling of extraction techniques based on supported liquid membranes to capillary electrophoresis for treatment and subsequent analysis of complex samples.

  3. Nonadiabatic hybrid quantum and molecular mechanic simulations of azobenzene photoswitching in bulk liquid environment.

    Science.gov (United States)

    Böckmann, Marcus; Doltsinis, Nikos L; Marx, Dominik

    2010-01-21

    A nonadiabatic hybrid quantum and molecular mechanical (na-QM/MM) molecular dynamics scheme has been implemented recently combining the nonadiabatic Car-Parrinello molecular dynamics method by Doltsinis and Marx [Phys. Rev. Lett. 2002, 88, 166402] with the QM/MM coupling approach by Laio et al. [J. Chem. Phys. 2002, 116, 6941]. Here an extensive validation of the underlying, density functional theory based, electronic structure methods by comparison to CASPT2 ab initio data is presented for the case of azobenzene. The "on the fly" na-QM/MM method is then applied to study Z-->E and E-->Z photoisomerization of azobenzene in a bulk liquid environment. The isomerization mechanism is found to be a pedal motion of the central CN horizontal lineNC group in both cases. While the Z-->E reaction is barely affected by the environment, E-->Z photoisomerization is slowed down considerably in the liquid compared to the gas phase. This effect is due to the fact that reorientation of the phenyl rings is significantly hindered in the liquid by steric nearest neighbor interactions. Nonradiative decay is found to be substantially faster for Z-AB (subpicosecond regime) than for E-AB (picosecond regime). The main molecular motions responsible for nonadiabatic coupling have been identified as the oscillations in the NN and CN bond lengths, the CNN bond angles, and the CNNC dihedral angle. PMID:19928885

  4. Liquid membranes and process for uranium recovery therewith

    International Nuclear Information System (INIS)

    A liquid membrane system consisting of water-in-oil type emulsions dispersed in water, which is capable of extracting uranium-containing ions from an aqueous feed solution containing uranium ions at a temperature in the range of 250C to 800C, is described. The emulsion comprises an aqueous interior phase surrounded by a surfactant-containing exterior phase. The exterior phase is immiscible with the interior phase and comprises a transfer agent capable of transporting selectively the desired uranium-containing ions and a solvent for the transfer agent. The interior phase comprises a reactant capable of removing uranium-containing ions from the transfer agent and capable of changing the valency of the uranium in uranium-containing ions to a second valency state and converting the uranium-containing ions into a nonpermeable form. (U.K.)

  5. 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...

  6. 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.

  7. 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.

  8. Membrane–solvent selection for CO2 removal using membrane gas–liquid contactors

    NARCIS (Netherlands)

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

    2004-01-01

    Membrane gas–liquid contactors can provide very high interfacial area per unit volume, independent regulation of gas and liquid flows and are insensitive to module orientation, which make them very attractive in comparison with conventional equipments for offshore application. However, the membrane

  9. 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

  10. 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...

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

    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

  13. 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.

  14. 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)

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

    International Nuclear Information System (INIS)

    Models which describe the permeation of strontium cation through liquid membranes are shown in this paper. Partition coefficients have been determined radiometrically, using Sr-85 tracer. The results were treated according to the theory developed by Danesi using simple equation. The permeation of Sr2+ using 18-crown-6 crown ether (18C6) and picric acid in bulk liquid toluene membrane systems with and without surface/active substances (SPAN 80, ECA 4360) has been studied. The transport of Sr2+ using 18-C-6 ether as a carrier and picrate as a co-counter ion through hollow fiber supported dichlorobenzene liquid membrane has been studied too. A polypropylene hollow fiber ACCUREL PP type S6/ENKA and a permeation device with a single hollow fiber module with on-line radiometric detection of strontium using Sr-85 tracer, was used. This type of permeation system has shown reproducible results, fast and effective permeation. Results prove the possible mechanism of strontium cation transport though liquid membrane. Another subject of study was the transport of metal ions (Ca2+, Sr2+, Ba2+, Na+, K+, Cs+) using (18C6) as a carrier and picrate as co/counter ion through hollow fiber supported dichlorobenzene liquid membrane using capillary isotachophoresis (ITP) measurement of the cations concentration. The experimental results obtained using ITP method for Sr2+ concentration determination are in good agreement with those obtained by on-line radiometric detection using Sr-85 tracer, under the same conditions (feed, membrane, strip, hollow fiber and the same pertraction device). The ITP method could be successfully used for analyses of samples containing a mixture of all separated cations. The results of this study indicate that the polypropylene hollow fiber supported dichlorobenzene membrane is suitable for studied metal cation transport using 18C6 as a carrier and a picrate as co-counter ion. This combination enables fast and effective cation separation. The pertraction module

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

    International Nuclear Information System (INIS)

    The determination of surfactant in liquid membrane has been done. The surfactant is span-80 (sorbitol-monooleate), the liquid membrane phase was the organic phase (O), the internal liquid phase (W) with ratio O/W = 1, and surfactant. The organic phase using D2EHPA in the kerosene and the internal liquid phase using aqua des or acid nitric. The determination of surfactant with variation of span-80 (0,25 - 2%) in the liquid membrane volume. The speed of stirrer was 3500 rpm in 20 minute. The ratio of liquid membrane phase form and external phase (aqua des or acid nitric) was 1, the speed of stirrer was 350 rpm in 10 minute (permeation process). The liquid phase and the liquid membrane phase was separated and then determinated the volume of liquid membrane, the result of percentage of span-80 was 0,25 % volume. The extraction of yttrium and dysprosium in 2 M HNO3 was Kdy = 2.945 and KdDy = 0.019

  17. Design criteria for extraction with chemical reaction and liquid membrane permeation

    Science.gov (United States)

    Bart, H. J.; Bauer, A.; Lorbach, D.; Marr, R.

    1988-01-01

    The design criteria for heterogeneous chemical reactions in liquid/liquid systems formally correspond to those of classical physical extraction. More complex models are presented which describe the material exchange at the individual droplets in an extraction with chemical reaction and in liquid membrane permeation.

  18. Preparation of a silicate membrane at a liquid/liquid interface and its doping with a platinum ion

    Czech Academy of Sciences Publication Activity Database

    Jänchenová, Hana; Štulík, K.; Mareček, Vladimír

    2006-01-01

    Roč. 591, č. 1 (2006), s. 41-45. ISSN 0022-0728 R&D Projects: GA ČR GA203/03/0822 Institutional research plan: CEZ:AV0Z40400503 Keywords : liquid/liquid interfaces * sol-gel * silicate membrane * composite layers Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.339, year: 2006

  19. The interfacial thermal resistance between bulk superfluid 3He and liquid 3He in aerogel at ultralow temperatures

    International Nuclear Information System (INIS)

    We present the first measurements of the thermal boundary resistance of the interface between the two different liquid phases: bulk superfluid and liquid confined in aerogel. We set up a heat flow along a liquid-filled tube containing a plug of 98% aerogel, and measure the temperature at the two ends. At the lowest temperatures, the resistance is dominated by the boundary resistance at the aerogel surfaces and is unaffected by the superfluid transition of the 3He in the aerogel. Whereas in conventional Kapitza resistance the boundary conductance is limited by acoustic mismatch, here the conductance is limited by an energy mismatch, since quasiparticles with energies above the bulk B-phase gap may freely cross the interface, while those with lower energies are confined to the aerogel

  20. A size-dependent constitutive model of bulk metallic glasses in the supercooled liquid region

    Science.gov (United States)

    Yao, Di; Deng, Lei; Zhang, Mao; Wang, Xinyun; Tang, Na; Li, Jianjun

    2015-01-01

    Size effect is of great importance in micro forming processes. In this paper, micro cylinder compression was conducted to investigate the deformation behavior of bulk metallic glasses (BMGs) in supercooled liquid region with different deformation variables including sample size, temperature and strain rate. It was found that the elastic and plastic behaviors of BMGs have a strong dependence on the sample size. The free volume and defect concentration were introduced to explain the size effect. In order to demonstrate the influence of deformation variables on steady stress, elastic modulus and overshoot phenomenon, four size-dependent factors were proposed to construct a size-dependent constitutive model based on the Maxwell-pulse type model previously presented by the authors according to viscosity theory and free volume model. The proposed constitutive model was then adopted in finite element method simulations, and validated by comparing the micro cylinder compression and micro double cup extrusion experimental data with the numerical results. Furthermore, the model provides a new approach to understanding the size-dependent plastic deformation behavior of BMGs.

  1. Characteristics and trihalomethane formation reactivity of dissolved organic matter in effluents from membrane bioreactors with and without filamentous bulking.

    Science.gov (United States)

    Xia, Chufan; Ma, Defang; Gao, Baoyu; Hu, Xinxiao; Yue, Qinyan; Meng, Yingjie; Kang, Shuyu; Zhang, Bei; Qi, Yuanfeng

    2016-07-01

    In this study, synthetic wastewater was treated by two identical membrane bioreactors (MBRs): the normal sludge MBR (NS-MBR) and the bulking sludge MBR (BS-MBR). Effects of filamentous bulking on the characteristics and trihalomethane (THM) formation reactivity of MBR effluent dissolved organic matter (EfOM) were investigated. Filamentous sludge bulking had no significant influence on the regulated MBR effluent water quality except NO2-N and NO3-N. NS-MBR effluent had more low molecular weight (LMW) (<5kDa) EfOM (92.43%) than BS-MBR (75.18%). About two-thirds of EfOM from BS-MBR were hydrophilic substances. On the contrary, EfOM from NS-MBR exhibited higher hydrophobicity. The ratio of polysaccharides and proteins in MBR effluents increased after filamentous bulking. There were more protein-like materials, fulvic acid-like and humic acid-like in BS-MBR EfOM. The THM formation reactivity of BS-MBR EfOM was 30.15% of NS-MBR EfOM, whereas BS-MBR EfOM exhibited higher formation reactivity of bromine containing species. PMID:27017128

  2. 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.

  3. Cadmium bioavailability and speciation using the permeation liquid membrane

    Energy Technology Data Exchange (ETDEWEB)

    Bayen, Stephane [CABE, University of Geneva, Sciences II, 30 Quai Ernest Ansermet, CH 1211, Geneva 4 (Switzerland)]. E-mail: stephane.bayen@cabe.unige.ch; Worms, Isabelle [CABE, University of Geneva, Sciences II, 30 Quai Ernest Ansermet, CH 1211, Geneva 4 (Switzerland); Parthasarathy, Nalini [CABE, University of Geneva, Sciences II, 30 Quai Ernest Ansermet, CH 1211, Geneva 4 (Switzerland); Wilkinson, Kevin [Department of Chemistry, University of Montreal, CP 6128, succ. Centre-Ville, Montreal, QC H3C 3J7 (Canada); Buffle, Jacques [CABE, University of Geneva, Sciences II, 30 Quai Ernest Ansermet, CH 1211, Geneva 4 (Switzerland)

    2006-08-11

    The permeation liquid membrane (PLM) technique was used to evaluate cadmium speciation in media resembling natural freshwaters. A planar sheet PLM system was characterized by measuring Cd fluxes in the absence and presence of complexing agents such as citrate, malonate, nitrilotriacetate and the Suwannee River standard humic acid. Comparison with theoretical speciation calculations and the results of a Cd{sup 2+} selective electrode, showed that free Cd was correctly measured using the planar sheet PLM within the studied concentration range, i.e. 10{sup -8} to 10{sup -4} M. The effect of pH and potentially co-transported ions on Cd transport through the PLM was also studied. An example of the ability of the hollow-fiber PLM (HFPLM) to measure free Cd in the nM range is also presented. In order to evaluate the usefulness of the technique as a predictor of bioavailability, Cd PLM measurements (fluxes) were compared to Cd biouptake (internalization flux) for a freshwater alga, Chlorella kesslerii, in the absence and presence of SRHA. The use of PLM measurements is shown to be an attractive tool to better understand Cd biouptake.

  4. Separation of actinides using hollow fiber supported liquid membranes

    International Nuclear Information System (INIS)

    Hollow fiber supported liquid membrane (HFSLM) studies were carried out using TODGA (N,N,N',N'-tetraoctyl diglycolamide) - DHOA (di-n-hexyloctanamide) - NPH (normal paraffin hydrocarbon) and Cyanex-301-n-dodecane as carriers. The first carrier was employed to recover trivalent actinides and lanthanides from simulated high level waste (SHLW) of pressurized heavy water reactor (PHWR) origin. Subsequently, the mutual separation of the actinides and the lanthanides was demonstrated with the second carrier (Cyanex-301-n-dodecane). Quantitative transport of Am(III) and Nd(III) was observed in 45 min from a feed solution (500 mL) containing 1 g/L Nd spiked with 241Am at 3 M HNO3. Similarly, all the lanthanides (La, Ce, Pr, Nd and Sm) and tracer Am(III) were quantitatively recovered in 30 min from SHLW. No significant transport of other metal ions present in SHLW was observed. Quantitative and selective recovery of Am(III) was achieved by Cyanex-301-n-dodecane from feed solution containing 1 g/L total lanthanides spiked with 241Am tracer. The physical stability of HFSLM was reasonably good during continuous operation for over 72 h. Radiolytic stability of solvent and hollow fibre module up to 500 kGy dose was also satisfactory. (orig.)

  5. High speed laser activated membrane introduction mass spectrometric evaluation of bulk methylcyclohexane dehydrogenation catalysts

    International Nuclear Information System (INIS)

    Laser activated membrane introduction mass spectrometry (LAMIMS) is a modification of membrane introduction mass spectrometry where a silicone membrane serves as a separator between an analyte stream and the vacuum of a quadrupole mass spectrometer. Carbon paper, commonly used as a fuel cell gas diffusion layer, has been overlaid upon the silicone membrane to serve as a support for catalyst array libraries that are heated by a CO2 laser during evaluation. The LAMIMS reactor is a closed environment permitting steady state exposure of the catalyst library to the reactant stream. In this work, Pt/Al2O3 catalysts for the dehydrogenation of methylcyclohexane (MCH) to toluene have been ranked by LAMIMS. Spot-to-spot evaluation times (after preconditioning) are 1 min in this study. The data suggests that by optimization of signal-to-noise and spot-to-spot dwell times, ranking can be conducted at substantially under a minute per array spot candidate

  6. Design and simulation of Pt-based microhotplate, and fabrication of suspended dielectric membrane by bulk micromachining

    Science.gov (United States)

    Prasad, Mahanth; Yadav, R. P.; Sahula, V.; Khanna, V. K.

    2012-10-01

    The paper presents the design and simulation of double spiral Pt-based microhotplate (MHP) for gas sensing application. A platinum resistor of 52 Ω has been designed and simulated on a 0.3 micron thick SiO2 suspended membrane of size 40 × 40 μm2 using ANSYS. The SiO2 membrane of size 40 × 40 μμm2 and thickness 0.3 micron has been fabricated successfully by bulk micromachining in TMAH) solution. The simulated temperature and transit time response of microhotplate were obtained as 600.5 °C and 0.2 ms respectively at 4.8 mW power consumption.

  7. Estimating the density scaling exponent of viscous liquids from specific heat and bulk modulus data

    OpenAIRE

    Pedersen, Ulf R.; Hecksher, Tina; Jakobsen, Bo; Schrøder, Thomas B.; Gnan, Nicoletta; Bailey, Nicholas P.; Dyre, Jeppe C.

    2009-01-01

    It was recently shown by computer simulations that a large class of liquids exhibits strong correlations in their thermal fluctuations of virial and potential energy [Pedersen et al., Phys. Rev. Lett. 100, 015701 (2008)]. Among organic liquids the class of strongly correlating liquids includes van der Waals liquids, but excludes ionic and hydrogen-bonding liquids. The present note focuses on the density scaling of strongly correlating liquids, i.e., the fact their relaxation time tau at diffe...

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

    International Nuclear Information System (INIS)

    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)

  10. 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.

  11. Bulk separation of actinides and lanthanides from actual high level liquid waste of PUREX origin using tetra-(2-ethylhexyl) diglycolamide

    International Nuclear Information System (INIS)

    Partitioning and transmutation of minor actinides is emerging as one of the preferred options for the management of high level liquid waste (HLLW) generated during the reprocessing of spent nuclear fuel. Various processes viz., DIAMEX process, TRUEX process etc. have been developed and are being tested for their use in actual application. Of late, a new class of extractant, diglycolamides, with good radiation and chemical stability and complete incinerability has emerged as the front runner for partitioning. This paper deals with the testing of indigenous and bulk synthesized N,N,N',N' tetra-(2-ethylhexyl) diglycolamide (TEHDGA) for the bulk separation of actinides and lanthanides (An and Ln) from actual HLLW

  12. 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...

  13. Performance characteristics of cross-flow membrane contactors for liquid desiccant systems

    International Nuclear Information System (INIS)

    Highlights: • Different types of flat plate membrane contactors developed to eliminate carryover in liquid desiccant systems. • Two-dimensional steady-state model developed to predict performance of contactors. • The simulated results are found to be in good agreement with experimental findings. • Performance of the contactors depends significantly on the membrane characteristics. • Parametric analysis carried out to select best operating ranges of design parameters. - Abstract: Membrane based indirect contact liquid desiccant dehumidification technology subsides the serious concern of liquid desiccant droplet carryover observed in conventional direct contact liquid desiccant systems. In the membrane contactor the air and liquid desiccant streams flow in alternate channels in cross-flow arrangement, separated by micro-porous semi-permeable hydrophobic membranes. Only water vapor can pass through the membranes but liquid desiccant cannot permeate. A two-dimensional steady-state mathematical model for semipermeable membrane based indirect contactors as dehumidifiers for liquid desiccant dehumidification applications has been developed. The model can predict the air and desiccant parameters inside the dehumidifier and the outlet parameters for a given input parameters. Five different membrane contactors have been fabricated and series of experiments have been conducted to validate the mathematical model. Aqueous solution of lithium chloride has been used as desiccant. The maximum deviations between experimental and predicted values are within ±10% for outlet specific humidity and outlet enthalpy of air, ±15% deviation in dehumidification effectiveness and ±20% deviation in enthalpy effectiveness. The distributions of major parameters viz. temperature, humidity, concentration, etc., within the contactor have been presented. Parametric analysis has been carried out to study the effects of membrane characteristics, contactor design, fluid flow rates, ambient

  14. Semiempirical self-consistent polarization description of bulk water, the liquid-vapor interface, and cubic ice.

    Science.gov (United States)

    Murdachaew, Garold; Mundy, Christopher J; Schenter, Gregory K; Laino, Teodoro; Hutter, Jürg

    2011-06-16

    We have applied an efficient electronic structure approach, the semiempirical self-consistent polarization neglect of diatomic differential overlap (SCP-NDDO) method, previously parametrized to reproduce properties of water clusters by Chang, Schenter, and Garrett [ J. Chem. Phys. 2008 , 128 , 164111 ] and now implemented in the CP2K package, to model ambient liquid water at 300 K (both the bulk and the liquid-vapor interface) and cubic ice at 15 and 250 K. The SCP-NDDO potential retains its transferability and good performance across the full range of conditions encountered in the clusters and the bulk phases of water. In particular, we obtain good results for the density, radial distribution functions, enthalpy of vaporization, self-diffusion coefficient, molecular dipole moment distribution, and hydrogen bond populations, in comparison to experimental measurements. PMID:21370904

  15. 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...... Lame parameter), together with Debye temperature, gradually decrease with increasing temperature through the glass transition temperature as the Poisson's ratio increases. The behavior of the velocity of transverse wave vs. temperature in the supercooled liquid region could be explained by viscosity...... flow, rather than the two different crystallization processes in the region, suggested in the literature. No decomposition was detected at a temperature only 5 K below the crystallization temperature....

  16. Collective dynamics of water in the living cell and in bulk liquid. New physical models and biological inferences

    OpenAIRE

    Preoteasa, Eugen A.; Apostol, Marian V.

    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 i...

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

    International Nuclear Information System (INIS)

    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

  18. Membrane-Based, Liquid–Liquid Separator with Integrated Pressure Control

    OpenAIRE

    Adamo, Andrea; Heider, Patrick L.; Weeranoppanant, Nopphon; Jensen, Klavs F.

    2013-01-01

    We describe the development and application of an improved, membrane-based, liquid–liquid separator. Membrane-based separation relies on the exploitation of surface forces and the use of a membrane wetted by one of the phases; however, successful separation requires accurate control of pressures, making the operation and implementation cumbersome. Here we present an improved separator design that integrates a pressure control element to ensure that adequate operating conditions are always mai...

  19. 78 FR 54775 - Bulk Packaging To Allow for Transfer of Hazardous Liquid Cargoes

    Science.gov (United States)

    2013-09-06

    ... DOT Department of Transportation FR Federal Register IBC Intermediate Bulk Container IBC Code..., we published in the Federal Register (77 FR 14327) a notice of proposed rulemaking (NPRM) titled Bulk... portable tank. (77 FR 14327, at 14330),'' (emphasis added) The above excerpt provides a general...

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

    International Nuclear Information System (INIS)

    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. 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.

  2. Influence of protein bulk properties on membrane surface coverage during immobilization.

    Science.gov (United States)

    Militano, Francesca; Poerio, Teresa; Mazzei, Rosalinda; Piacentini, Emma; Gugliuzza, Annarosa; Giorno, Lidietta

    2016-07-01

    Biomolecules immobilization is a key factor for many biotechnological applications. For this purpose, the covalent immobilization of bovine serum albumin (BSA), lipase from Candida rugosa and protein G on differently functionalized regenerated cellulose membranes was investigated. Dynamic light scattering and electrophoresis measurements carried out on biomolecules in solution indicated the presence of monomers, dimers and trimers for both BSA and protein G, while large aggregates were observed for lipase. The immobilization rate and the surface coverage on functionalized regenerated cellulose membranes were studied as a function of biomolecule concentration. Results indicated that the saturation coverage of BSA and protein G was concentration independent (immobilized protein amount of 2.40±0.03mg/g and 2.65±0.07mg/g, respectively). Otherwise, a different immobilization kinetics trend was obtained for lipase, for which the immobilized amount increases as a function of time without reaching a saturation value. Atomic force microscopy (AFM) micrographs showed the formation of monolayers for both BSA and protein G on the membrane surface, while a multilayer structure is found for lipase, in agreement with the trends observed in the related immobilization kinetics. As a result, the morphology of the proteins layer on the membrane surface seems to be strictly dependent on the proteins behavior in solution. Besides, the surface coverage has been described for BSA and protein G by the pseudo second order models, the results indicating the surface reaction as the controlling step of immobilization kinetics. Finally, enzyme activity and binding capacity studies indicated the preservation of the biomolecule functional properties. PMID:27022871

  3. Cyclic Voltammetry of Highly Hydrophilic Ions at a Supported Liquid Membrane

    Czech Academy of Sciences Publication Activity Database

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

    2002-01-01

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

  4. An adaptive controller for Wolsong NGS bulk liquid zone control of RRS

    International Nuclear Information System (INIS)

    The evaluation and inspection of linear stability of Liquid Zone Controller (LZC) has been being performed with design data and actual program parameters installed in plant Digital Control Computers (DCC) during licensing stage of Wolsong Units 2,3 and 4. The study was done to identify the candidates -the vulnerable devices or control parameters on stability when plant is undergone with improper tuning or control components' aging. The time constant of LZC valve was analyzed as the critical parameter among the candidates. However, the surveillance requirements could not be applied to the process control system such as control devices of RRS. The response time of RRS controllers have not been measured since commissioned. The fine tuning parameters and gains should have been justified with an analysis, but is tuned with experiences learned from previous CANDU plants. With limited simulation results, we have confirmed that no fundamental barriers of RRS bulk control for Wolsong 2/3/4 exist. The dynamic calibration in DCC program could correct continuously a wrong input-sensing signal of log neutron power such like an adaptive system. The first order lag term of the actuator, LZC valve, is the most critical among other sensing and actuating devices. It is, however, a quite large degradation from design value when it disturbs the plant. With a help of MRAS (model reference adaptive system) regulator in this study, the adaptive controller with an aged actuator has a possibility to cope with the worst situation with which the DCC program could not deal. It will give guidance for plant engineer when the tuning is necessary or preventive maintenance is planned against aging. If a fault tolerant control scheme is applied, an unstable operation of RRS will be relieved from such an unexpected malfunction. We recommend that the precautions and limitations for dynamic response of LZC be considered to apply the vulnerable parameters identified in this study. In this study we

  5. 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.

  6. Atomic-Scale Structural Evolution and Stability of Supercooled Liquid of a Zr-Based Bulk Metallic Glass

    International Nuclear Information System (INIS)

    In this Letter, direct experimental evidence is provided for understanding the thermal stability with respect to crystallization in the Zr41.2Ti13.8Cu12.5Ni10Be22.5 glass-forming liquid. Through high-resolution transmission electron microscopy, the atomic-structure evolution in the glass-forming liquid during the isothermal annealing process is clearly revealed. In contrast with the existing theoretical models, our results reveal that, prior to nanocrystallization, there exists a metastable state prone to forming icosahedralike atomic clusters, which impede the subsequent crystallization and hence stabilize the supercooled liquid. The outcome of the current research underpins the topological origin for the excellent thermal stability displayed by the Zr-based bulk metallic glass.

  7. 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.

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

    OpenAIRE

    Hoarfrost, Megan Lane

    2012-01-01

    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 additio...

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

    Science.gov (United States)

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

    2012-08-01

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

  10. 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.

  11. Structures of bulk amorphous Zr41Ti14Ni10Cu12.5Be22.5 alloy in amorphous, crystalline, supercooled liquid and liquid states

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The amorphous and crystal structures of Zr41Ti14Ni10Cu12.5Be22.5 alloy have been analyzed with X-ray diffractometer. The structures of bulk amorphous Zr41Ti14Ni10Cu12.5B22.5 alloy in solid, supercooled liquid and liquid states are almost of the same structure. The RDFs (Radius Distribution Function), the first coordination number, the first coordination radius, the correlation radius and atom number of the cluster were calculated for bulk amorphous Zr41Ti14Ni10Cu12.5B22.5 alloy in different states. The first coordination sphere radii and the first coordination numbers are 0.312nm, 11.2 in solid state, 0.301nm, 10.932 in supercooled liquid region and 0.305nm, 11.296 in liquid state. The crystal structure of Zr41Ti14Ni10Cu12.5B22.5 alloy is consisted of several intermetallic compounds which are CuZr2, Be2Zr, etc. The reason of formation glass for this alloy is that there is a larger resistance for atoms to rearrange and form intermetallic compounds in a long range order.

  12. 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.

  13. 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. PMID:22608433

  14. Separation of Biogas by Supported Ionic Liquid Membranes

    Czech Academy of Sciences Publication Activity Database

    Izák, Pavel; Sedláková, Zuzana; Friess, K.

    Bratislava: Slovak Society of Chemical Engineering, 2015 - (Markoš, J.), s. 57 ISBN 978-80-89475-14-8. [International Conference of Slovak Society of Chemical Engineering /42./. Tatranské Matliare (SK), 25.05.2015-29.05.2015] R&D Projects: GA MŠk LH14006 Institutional support: RVO:67985858 Keywords : membrane separation * membrane technology * electrochemical applications Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  15. Selective removal of H2S from sour gases with microporous membranes. Part II. A liquid membrane of water-free tertiary amines

    NARCIS (Netherlands)

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

    1993-01-01

    In the present study the application of a liquid membrane for selective removal of H2S from gases also containing CO2 was investigated. The liquid membrane was filled with pure methyl-di-ethanol-amine (MDEA). A theoretical model was developed to describe: (a) the chemical equilibrium between the dis

  16. The preparation and characterisation of hydrophobic polymeric membranes for use in the separation of liquid mixtures using pervaporation separation processes

    OpenAIRE

    Byrne, Susan M.

    1998-01-01

    Pervaporation is a membrane separation process used to separate liquid mixtures Separation is achieved by establishing a concentration vapour-pressure gradient across the membrane. Polyurethane (PU) and polydimethylsiloxane (PDMS) membranes were prepared from their prepolymers by solution casting Dilute aqueous solutions of ethyl acetate, methyl isobutyl ketone, methyl ethyl ketone and aniline were separated using these polyurethane and polydimethylsiloxane polymeric membranes at temperat...

  17. Proton Conducting Polymer Membrane Using The Ionic Liquid 2-Hydroxyethylammonium Lactate For Ethanol Fuel Cells

    Science.gov (United States)

    Oliveira, L.; José, N. M.; Boaventura, J.; Iglesias, M.; Mattedi, S.

    2011-12-01

    In this work, there were developed a proton conducting polymer membrane using an ammonium based protic ionic liquid: 2-hydroxyethylamominum lactate for use in proton exchange fuel cells (PEMFC). This kind of ionic liquid has been proven to be biodegradable and they have potentially low toxicity besides low cost of preparation, simple synthesis and purification. The prepared membranes are hybrid organic-inorganic materials. The polymeric matrix is prepared with polydimethylsiloxane (PDMS) mixed with tetraethoxysilane (TEOS) in a ratio of 70/30% in weight. Then, the eletrolytical mixture containing sodium monododecylsulfate (SDS) and the ionic liquid was introduced in the lattice near the gel point, there were used different proportions of the eletrolyte from 5 to 30% in weight. The prepared membranes were characterized using infrared spectroscopy (FTIR), X-ray diffraction (DRX), termogravimetric analysis (TGA), scanning electronic microscopy (SEM) and conductivity and impedance measurements. The prepared materials are flexible, with good thermal and mechanical stability and with a great potential to be used as conducting membranes of fuel cells. The used mixture minimizes the lixiviation lost of the ionic liquid from the polymeric membrane and enhances the cell efficiency if compared with traditional synthetic membranes.

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

    International Nuclear Information System (INIS)

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

  19. 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...

  20. Enrichment of zinc isotopes by a liquid membrane system using a crown ether

    International Nuclear Information System (INIS)

    A liquid membrane system to enrich zinc isotope was investigated. The liquid membrane was composed of a solution of dicyclohexano-18-crown-6 in chloroform. Zinc chloride dissolved in diluted hydrochloric acid was used as a feed phase. A receiving phase was made of a 0.001 M HCl solution. The zinc isotopes were enriched (1) at the interface of the liquid-membrane/feed-phase and (2) at that of the liquid-membrane/receiving-phase. The separation factor attained in the system was α = 1.049 for the separation of 64Zn and 66Zn. The enrichment factor of 66Zn relative to 67Zn was ε = -0.053, which is in the inverse direction of enrichment by a liquid-liquid extraction. The enrichment factor of 64Zn to 66Zn showed a different value from that of 66Zn to 68Zn, regardless of their similar mass difference. The isotope effects in the Zn-crown complex were dominated by the field shift of electronic energy in the isotope atom. This is in contrast to the Bigeleisen-Mayer approximation for a chemical exchange reaction. Trace amounts of zinc are injected into the primary coolant of boiling water reactors in order to suppress 60Co build-up. The use of 64Zn-depleted zinc suppresses the production of 65Zn within the reactor. Zinc isotopes are also useful precursors of radiopharmaceuticals

  1. G-protein activity in Percoll-purified plasma membranes, bulk plasma membranes, and low-density plasma membranes isolated from rat cerebral cortex

    Czech Academy of Sciences Publication Activity Database

    Bouřová, Lenka; Stöhr, Jiří; Lisý, Václav; Rudajev, Vladimír; Novotný, Jiří; Svoboda, Petr

    2009-01-01

    Roč. 15, č. 4 (2009), BR111-BR122. ISSN 1234-1010 R&D Projects: GA MŠk(CZ) LC554; GA MŠk(CZ) LC06063; GA ČR(CZ) GA309/06/0121; GA AV ČR(CZ) IAA500110606 Institutional research plan: CEZ:AV0Z50110509 Keywords : rat cerebral cortex * plasma membrane * G-protein activity Subject RIV: CE - Biochemistry Impact factor: 1.543, year: 2009

  2. Hollow fibre supported liquid membranes for separations relevant to radioactive waste management

    International Nuclear Information System (INIS)

    Separation science plays a pivotal role in many hydrometallurgical processes, including industrial waste water treatment. Out of the various separation techniques, solvent extraction, ion-exchange and precipitation are considered as the work horse for various industrial applications. Of late, there is a growing interest in membrane based separation methods which are considered environmentally benign. A combination of solvent extraction and membrane diffusion, alternatively known as liquid membrane (LM) technique, has drawn considerable attention of the separation scientists. LM based separation methods are associated with several advantages over conventional solvent extraction such as simultaneous extraction and stripping, generation of low volume of volatile organic carbons (VOCs), low operating cost, etc. LMs containing selective carrier extractants have been proposed as alternatives to solvent extraction based methods for selective separation and concentration of metal ions from dilute aqueous solutions. Though solvent extraction based separation methods have been used extensively metal ion separations in nuclear fuel cycle, there is a need to explore liquid membrane based separations. Furthermore, the supported liquid membrane based separations are not suitable for large scale processes due to low flux and membrane stability. Therefore, alternative liquid membrane separation methods such as Emulsion Liquid Membranes (ELM) and Hollow Fiber Supported Liquid Membrane (HFSLM) with high metal transport flux appear promising due to large effective surface area with resultant high mass transfer rates. At Radiochemistry Division, extensive work has been carried out on HFSLM technique for possible applications in several separations relevant at the back end of the nuclear fuel cycle. Separation of Am(III) from simulated high level waste by HFSLM technique was demonstrated for the first time. A pilot scale run was carried out at 20 L scale for the actinide partitioning

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

    Science.gov (United States)

    2012-03-09

    ..., issue of the Federal Register (73 FR 3316). D. Public Meeting We do not now plan to hold a public... 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...

  4. 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.

  5. Modeling of gadolinium recovery from nitrate medium with 8-hydroxyquinoline by emulsion liquid membrane

    International Nuclear Information System (INIS)

    The extraction equilibrium of Gd(III) from nitrate medium by 8-hydroxyquinoline (HOX) in toluene was studied. Liquid-liquid investigations were first carried out. Based on the equilibrium results, the extraction of Gd(III) from aqueous nitrate medium into an emulsion liquid membrane system (ELM) containing 8-hydroxyquinoline in toluene as extractant, HNO3 as stripping solution, Span-80 as surfactant was studied. The stability of the prepared ELM was studied in terms of the degree of membrane breakage. The different parameters affecting the permeation of gadolinium (III) were also studied. A general permeation model for the recovery of Gd(III) by the selected membrane is presented. The internal mass transfer in the water in oil (W/O) emulsion drop, the external mass transfer around the drop, the rates of formation and decomposition of the complex at the external aqueous-organic interface were considered.

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

    International Nuclear Information System (INIS)

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

  8. Superplasticity and structure of bulk metallic glass vit-1 by tensile plastic deformation in the supercooled liquid region

    International Nuclear Information System (INIS)

    It was investigated by tensile plastic deformation behavior of metallic glasses bulk (Zr41.25Ti13.75Ni10Cu12.5Be22.5) in the supercooled liquid region at different strain rates and temperatures. When the temperature rises to a value of 675 K test, which is near the crystallization temperature of the glass and decreasing the speed on the curves of test strain appears more pronounced hardening sites that suggest that under the action of deformation in a homogeneous vitreous material falls reinforcing particles of crystalline phases. Choosing the temperature-strain rate conditions of the metallic glass to a supercooled liquid region can be deformed samples up to several hundred percent to obtain a sample of the original material structure of the metallic glass, or a composite of glass and metal nanocrystalline secretions

  9. 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...

  10. Purification of Raw Biogas by Supported Liquid Membranes

    Czech Academy of Sciences Publication Activity Database

    Izák, Pavel; Kárászová, Magda; Sedláková, Zuzana; Morávková, Lenka; Šolcová, Olga

    Praha : Česká společnost průmyslové chemie, 2014, s. 16. ISBN 978-80-86238-61-6. [mezinárodní chemicko-technologická konference /2./. Mikulov (CZ), 07.04.2014-09.04.2014] Institutional support: RVO:67985858 Keywords : membrane separation * raw biogas * gas mixture Subject RIV: CA - Inorganic Chemistry

  11. Cyclic Voltammetry of Biopolymer Heparin at PVC Plasticized Liquid Membrane

    Czech Academy of Sciences Publication Activity Database

    Samec, Zdeněk; Trojánek, Antonín; Langmaier, Jan; Samcová, E.

    2003-01-01

    Roč. 5, - (2003), s. 867-870. ISSN 1388-2481 R&D Projects: GA ČR GA203/04/0424 Institutional research plan: CEZ:AV0Z4040901 Keywords : cyclic voltammetry * PVC plasticized liquit membrane * heparin Subject RIV: CG - Electrochemistry Impact factor: 2.300, year: 2003

  12. Development of advanced membrane process for treatment of radioactive liquid wastes

    International Nuclear Information System (INIS)

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

  13. Liquid-liquid immiscibility under non-equilibrium conditions in a model membrane: an X-ray synchrotron study.

    Science.gov (United States)

    Tessier, Cedric; Staneva, Galya; Trugnan, Germain; Wolf, Claude; Nuss, Philippe

    2009-11-01

    Several non-random lipid mixtures have been proposed as models of lipid plasma membrane, as they mimic the ability of biomembranes to form lateral domains. Biological membranes are characterised by a succession of localised transient steady-state lipid organisations rather than stable equilibria. This suggests that several quasi at-equilibrium lipid organisations may exist at different times in the same local patch of membranes. Identification of the conditions which can mimic heterogeneous dynamic membrane states in a lipid membrane model is a challenge. This is of particular importance as the lateral organisation of lipids mixtures in fully equilibrated samples may differ from the arrangement found in quasi at-equilibrium conditions. To address this issue, we have performed a real-time synchrotron X-ray diffraction study in ternary mixtures of egg-phosphatidylcholine/egg-sphingomyelin and cholesterol using a 0.5 degrees C/15 s step within a 20-50-20 degrees C thermal cycle. In the present study, all ternary mixtures displayed lamellar phase separation. A d-spacing value was observed reversibly during the heating and cooling scan for each of the two coexisting phases. In mixtures with a cholesterol concentration from 20 to 50 mol%, a liquid-ordered (Lo) and liquid-disordered (Ld) phase separation was observed in the 20-50 degrees C thermal range. These results are discussed in terms of a specific interaction between lipid molecular aggregates. PMID:19720510

  14. Optical chirality of protonated tetraphenylporphyrin J-aggregate formed at the liquid liquid interface in a centrifugal liquid membrane cell

    Science.gov (United States)

    Wada, Sayaka; Fujiwara, Kazuhiko; Monjushiro, Hideaki; Watarai, Hitoshi

    2007-09-01

    J-aggregation of an achiral hydrophobic porphyrin, 5,10,15,20-tetraphenylporphyrin (H2TPP), at a toluene-4 M sulfuric acid interface was studied by a centrifugal liquid membrane-circular dichroism (CLM-CD) method. It was found for the first time that the exciton chirality sign of the interfacial J-aggregate of H4TPP2+ was affected by the rotational direction of the cylindrical CLM cell: a negative sign for clockwise (CW) rotation and a positive sign for anticlockwise (ACW) rotation. The sign of the measured optical chirality also depended on the injection position of the H2TPP stock solution in the rotating cell. Furthermore, it was observed that the rotational linear velocity of the aqueous phase was faster than that of the toluene phase, when the CLM cell was rotated at 7000 rpm. The effects of rotational direction and sample injection position on the optical chirality were overcome by the effect of chiral counter-ions such as (+)- or (-)-camphorsulfonic anions. From the observed results, a possible mechanism for the generation of the optical chirality of the interfacial J-aggregate was proposed taking into account an interfacial shear force and the spreading direction of H2TPP in the toluene phase.

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

    OpenAIRE

    Sanna Björkegren; Rose Fassihi Karimi; Anna Martinelli; Natesan Subramanian Jayakumar; Mohd Ali Hashim

    2015-01-01

    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 t...

  16. 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.

  17. Membrane methods for treating liquid radioactive wastes from the shelter to remove transuranium elements

    International Nuclear Information System (INIS)

    The possibility is studied of membrane treatment of liquid radioactive wastes (LRW) from the inside premises of the Chernobyl-4 Reactor Shelter to remove transuranium elements using ultra- and nanofiltration methods. The highest degree of decontamination (about 100%) was obtained for Pu and Am, and the lowest one, for Cs; for U and Sr, the values were intermediate. The effect of characteristics of a nanofiltration membrane on the LRW treatment efficiency is studied

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

    International Nuclear Information System (INIS)

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

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

    OpenAIRE

    Laura Parlapan

    2015-01-01

    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 wi...

  20. 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

  1. 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...... by the presence of various added substances. © 2006 American Chemical Society....

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

    International Nuclear Information System (INIS)

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

  3. 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.

  4. 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

  5. COP Evaluation for a Membrane Liquid Desiccant Air Conditioning System Using Four Different Heating Equipment

    OpenAIRE

    Abdel-Salam, Ahmed; Simonson, Carey

    2015-01-01

    Liquid desiccant air conditioning (LDAC) is a promising technology in terms of energy efficiency, comfort and indoor air quality. The major components of a LDAC system are the dehumidifier and regenerator. The most commonly used design of dehumidifiers/regenerators is the packed-bed, which might result in the entrainment of desiccant droplets in air streams. A promising solution for the entrainment of desiccant droplets in air streams is to use a liquid-to-air membrane energy exchanger (LAMEE...

  6. A model for a liquid membrane separation stage

    International Nuclear Information System (INIS)

    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

  7. How Ionic Liquid Changes Properties of Dense Polydimethylsiloxane Membrane?

    Czech Academy of Sciences Publication Activity Database

    Kohoutová, Marie; Sikora, Antonín; Hovorka, Š.; Randová, A.; Schauer, Jan; Poloncarzová, Magda; Izák, Pavel

    2010-01-01

    Roč. 14, 1-3 (2010), s. 78-82. ISSN 1944-3994 R&D Projects: GA ČR GA203/08/0465 Institutional research plan: CEZ:AV0Z40720504; CEZ:AV0Z40500505 Keywords : pervaporation * ionic liquid * fermentation Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 0.752, year: 2010

  8. Effective Purification of Biogas by Condensing-Liquid Membrane

    Czech Academy of Sciences Publication Activity Database

    Poloncarzová, Magda; Vejražka, Jiří; Veselý, Václav; Izák, Pavel

    2010-01-01

    Roč. 50, č. 3 (2010), s. 669-671. ISSN 1433-7851 R&D Projects: GA MPO FR-TI1/245 Institutional research plan: CEZ:AV0Z40720504 Keywords : biogas purification * condensing liquid * gas permeation Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 12.730, year: 2010

  9. Carried-mediated transport of rare earth elements through liquid membranes Pt. 5

    International Nuclear Information System (INIS)

    Stability of liquid membranes containing TBP, TOPO and HDEHP in n-dodecane, impregnated on a flat-sheet nucleoporous support, has been studied in pertraction systems of REEs. Under conditions of long-time uninterrupted pertraction, no signs of 'failed' membrane behavior were observed in any system investigated. In regard to permeability coefficient of metal under the same conditions without regeneration of membrane, SLMs containing TOPO appeared the most stable, then SLMs containing HDEHP followed and the less stable were SLMs with TBP. (author) 14 refs.; 4 figs.; 1 tab

  10. Anhydrous proton-conducting glass membranes doped with ionic liquid for intermediate-temperature fuel cells

    International Nuclear Information System (INIS)

    Highlights: ► Homogeneous [dema][TfO]/SiO2 hybrid glass electrolyte membranes are prepared. ► The conductivity of the hybrid glass membrane exceeds 10−2 S cm−1 in the temperature range of 120–220 °C. ► After annealing at 120 °C for 180 h, no decrease in conductivity can be observed. - Abstract: Proton-conducting glass membranes based on SiO2 monoliths and a protic ionic liquid (diethylmethylammonium trifluoromethanesulfonate, [dema][TfO]) as the anhydrous proton conductor were studied. The [dema][TfO]/SiO2 hybrid glass membranes were prepared via a sol–gel process. The stability and ionic conductivity of the glass membrane were investigated. The [dema][TfO]/SiO2 hybrid glass monoliths exhibit very high anhydrous ionic conductivities that exceed 10−2 S cm−1 at 120–220 °C.

  11. 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.

  12. Capillary wave fluctuations and intrinsic widths of coupled fluid-fluid interfaces: An x-ray scattering study of a wetting film on bulk liquid

    International Nuclear Information System (INIS)

    An x-ray specular reflectivity (XR) and off-specular diffuse scattering (XDS) study of the coupled thermal capillary fluctuations and the intrinsic profiles of two interacting fluid-fluid interfaces is presented. The measurements are carried out on complete wetting films of perfluoromethylcyclohexane (PFMC) on the surface of bulk liquid eicosane (C20), as a function of film thickness 30 or approx. 50 A) is comparable to the value expected for the bulk liquid-liquid interface (D→∞), determined by either the radius of gyration (5.3 A) or the bulk correlation length (4.8 A) of the alkane C20. The intrinsic liquid-vapor interfacial width is sharper (∼2 A) and remains essentially constant over the entire probed range of D

  13. Transfer of uranium (VI) through emulsion liquid membrane with N,N—dibutyloctanamide as a carrier

    Institute of Scientific and Technical Information of China (English)

    HanJing-Tian; SunGuo-Xin; 等

    1998-01-01

    The transfer behavior of uranium(VI) through an emulsion liquid membrane using N,N-dibutyloctanamide(DBOA) as a mobile casrrier has been investigated.The result shows that the liquid membrane process can effectively and rapidly concentrate uranium(VI) from nitric acid medium,and the optimum conditions for the transfer of uranium(VI) were obtained.

  14. Boron removal from seawater by supported liquid membranes

    OpenAIRE

    Coll Ausió, Mª Teresa; Fortuny Sanromá, Agustín; Leopold, Agnieszka Ana; Sastre Requena, Ana María

    2009-01-01

    Water covers 70% of the Earth’s surface but, even so water is becoming a scarce resource. In order to achieve the target 7.c of the Millennium Development Goals, to assure potable water for the people without sustainable access to it, alternative sources must be found. Considering that the oceans contain 97.5% of the earth’s water, seawater (SW) can be use as a source of safe drinking water and for irrigation; the salts contained are usually removed by membrane techniques, espe...

  15. 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

  16. Elucidating through-plane liquid water profile in a polymer electrolyte membrane fuel cell.

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yun (University of California, Irvine, CA); Chen, Ken Shuang

    2010-10-01

    In this paper, a numerical model incorporating micro-porous layers (MPLs) is presented for simulating water transport within the gas diffusion layers (GDLs) and MPLs as well as across their interfaces in a polymer electrolyte membrane (PEM) fuel cell. One-dimensional analysis is conducted to investigate the impacts of MPL and GDL properties on the liquid-water profile across the anode GDL-MPL and cathode MPL-GDL regions. Furthermore, two-dimensional numerical simulations that take MPLs into account are also carried out to elucidate liquid water transport, particularly through-plane liquid-water profile in a PEM fuel cell. Results from case studies are presented.

  17. 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

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

    International Nuclear Information System (INIS)

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

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

    Czech Academy of Sciences Publication Activity Database

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

    2006-01-01

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

  20. Purification Lanthanum of Solvent Extraction Hollow Fiber Supported Liquid Membrane by Using Potassium Hydroxide Treatment

    International Nuclear Information System (INIS)

    Full text: The objective of this research is to purify extracted lanthanum by hollow fiber supported liquid membrane. The liquid membrane was fabricated from a solution of D2EHPA dissolved in kerosene solvent before embedded in the microstructure of porous hollow fibers. In the experiment, ammonia was used to precipitate contaminates before liquid membrane extraction. Feed solution is prepared by digesting mixed rare earth with nitric acid and precipitated contaminates with ammonia solution (pH 7.6). Nitric acid solution, used as reagent strip was passed through the outside of the hollow fiber with the flow rate of 100 ml/min, whereas the feed was flow inside the hollow fiber. Results showed that the feed solution could reduce unwanted elements up to 79.3%, resulting in lanthanum with purity over 90.8 percent. Moreover, the solvents that are extracted using supported liquid membrane module with hollow fibers were found to have high purity of lanthanum to 95.3 percent

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

    Czech Academy of Sciences Publication Activity Database

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

    2012-01-01

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

  2. 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.

  3. 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.

  4. 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...

  5. Micro-electromembrane extraction across free liquid membranes. Instrumentation and basic principles

    Czech Academy of Sciences Publication Activity Database

    Kubáň, Pavel; Boček, Petr

    2014-01-01

    Roč. 1346, Jun (2014), s. 25-33. ISSN 0021-9673 R&D Projects: GA ČR(CZ) GA13-05762S Institutional support: RVO:68081715 Keywords : free liquid membranes * micro-electromembrane extraction * sample pretreatment Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 4.169, year: 2014

  6. 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)

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

    International Nuclear Information System (INIS)

    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 UF6 to UO2 in the cycle of nuclear fuel. This waste contains uranium concentration on average 7.0 mg L-1, and not be eliminated to the environmental. The waste was permeated using a cross-flow membrane cell in the pressure of the 1.5 MPa. The selectivity of the membranes for separation of uranium was between 83% and 90% for both tests. In the concentration tests the waste was concentrated around for 5 times. The surface layer of the membranes was evaluated before and after the tests by infrared spectroscopy (ATR-FTIR), field emission microscopy (FESEM) and atomic force spectroscopy (AFM). The membrane separation process is a technique feasible to and very satisfactory for treatment the liquid waste. (author)

  8. Alignment of nanostructure templated from lyotropic liquid crystals in membrane preparation

    International Nuclear Information System (INIS)

    This project is developing a new class of efficient and low-cost porous membrane materials for water treatment and desalination contributing to alleviate water shortage problems in Australia. We have recently synthesized well oriented Lyotropic liquid crystal (LLC) templated membranes with an average diameter of 2mm and enhanced the retention of the original order of nanostructure after photopolymerization. We will further improve the alignment of lyotropic liquid crystal when template is formed. These LLC membranes will have great potential to significantly reduce the energy used in the desalination processes. The alignment of the LLC nanostructure is very significant and challenging. Long-range orientational order of LLC has potential applications, such as tissue engineering, gas separation, water purification, and high-density storage media. However, polydomain structures of LLC samples are randomly distributed and alignment of the lyotropic liquid crystals of the template during the membrane synthesis process will improve the performance. Magnetic field and electric field are employed to align the LLC nanostructure in nanoparticles-doped samples before polymerization. After alignment, it is expected that the nanostructure pores are well oriented in the direction perpendicular to the surface of membrane. Small Angle Scattering of X-ray and Neutron will be performed as the main means to characterize and evaluate the alignment of the LLC nanostructure.

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

    CERN Document Server

    Twelker, K; Díez, M Montero; 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

    2014-01-01

    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 (TOF) mass spectroscopy for positive identification of the barium decay product.

  10. High temperature ceramic membrane reactors for coal liquid upgrading. Quarterly report No. 7, March 21, 1991--June 20, 1991

    Energy Technology Data Exchange (ETDEWEB)

    Tsotsis, T.T.

    1992-06-19

    Ceramic membranes are a new class of materials, which have shown promise in a variety of industrial applications. Their mechanical and chemical stability coupled with a wide range of operating temperatures and pressures make them suitable for environments found in coal liquid upgrading. In this project we will evaluate the performance of Sel-Gel alumina membranes in coal liquid upgrading processes under realistic temperature and pressure conditions and investigate the feasibility of using such membranes in a membrane reactor based coal liquid upgrading process. In addition, the development of novel ceramic membranes with enhanced catalytic activity for coal-liquid upgrading applications, such as carbon-coated alumina membranes, will be also investigated.

  11. Nucleation and growth of vapor bubbles in the liquid bulk and at a solid surface

    International Nuclear Information System (INIS)

    The main achievements in the study of the vapor phase origin in liquid and the subsequent growth of the vapor bubbles are presented briefly, and a number of issues on which there is no single opinion as yet are also outlined. The theory of homogeneous nucleation and a great number of experiments make it possible not only to explain qualitatively the causes of spontaneous formation of vapor nucleation centers in the metastable liquid but provides a simple computational relation for the estimating the intensity of this process. None of the existing hypotheses, however, can give a complete answer to the question of the mechanism of the vapor phase nucleation on a solid surface under ''pure conditions'', although this is a more pressing problem. At the same time, the role of cavities of reservoir type (with a narrow orifice) on the surface under heating as reliable stabilizers of the vapor formation (especially in liquid metals) is clarified from the practical point of view. Thus, the identification of technology for production of such cavities would make it possible to increase substantially the efficiency of heat transferring surfaces. Any computational relations for the growth of bubbles on the heating surface also are (and, according to the author, necessarily will be) approximate ones, although considerable success has been achieved in this field

  12. Supported liquid membranes (SLM) utilized to separation of elements 4f and uranium

    International Nuclear Information System (INIS)

    Liquid membranes have been an emerging technique used as an alternative for the separation and preconcentration of several metallic species. It have been applied as one alternative technique in the separation of metallic ions originating from several areas of industry like the hydrometallurgical, gases separation, biotechnology, treatment of nuclear and non-nuclear waste. The recovery of those metals through that technique has good potential to reduce, in very low levels, pollutants in processes. The liquid membrane is a solution, which is an organic solvent, water immiscible and with low dielectric constant, that is used as a diluent for an extractor agent, also called the sequestering agent, loader or metal transporter, which is absorbed in the microporous of a polymeric film and actuates as solid support of the liquid membrane. The extractor agent gets the metallic ion from the feed solution liberating it on the other side of the membrane, through stripping solution. Then, the extraction and stripping of the metallic species are carried out in a single step in the process, and has this advantage in relation to the liquid-liquid extraction that requests a large number of stages to obtain products with high purity. Besides, the technique of SLM needs low capital and operational cost, low energy consumption and use of little amount of extractor agent, making possible the use of expensive extractor agents. The main objective of this research is to investigate the influence of several parameters in the process of extraction of lanthanide metals and uranium originating from a simulated radioactive waste using as polymeric support membranes, PTFE and as loader calixarenes. The calixarenes are part of a very versatile class of macrocyclic compounds that can be functionalized, being obtained like this a great variety of multifunctional receptors. (author)

  13. Generation of Al nanoparticles via ablation of bulk Al in liquids with short laser pulses.

    Science.gov (United States)

    Stratakis, Emmanuel; Barberoglou, Marios; Fotakis, Costas; Viau, Guillaume; Garcia, Cecile; Shafeev, Georgy A

    2009-07-20

    Highly stable aluminum nanoparticles (NPs) are generated via ablation of bulk Al in ethanol using either femtosecond (fs) or picosecond (ps) laser sources. The colloidal NPs solutions obtained with fs pulses exhibit a yellow coloration and show an increased optical absorption between 300 and 400 nm, tentatively assigned to the plasmon resonance of nanosized Al. The corresponding solutions after ps ablation are gray colored and opalescent. The average size of the NPs formed ranges from 20 nm for the fs case to 60 nm for the ps case, while a narrower distribution is obtained using the shorter pulses. High Resolution Transmission Electron Microscopy (HRTEM) studies indicate that the NPs are mostly amorphous with single crystalline inclusions. Al NPs generated with short laser pulses slowly react with air oxygen due to the presence of a native oxide cladding, which efficiently passivates their surface against further oxidation. PMID:19654669

  14. High temperature ceramic membrane reactors for coal liquid upgrading. Quarter report No. 9, September 21, 1991--December 20, 1991

    Energy Technology Data Exchange (ETDEWEB)

    Tsotsis, T.T.

    1992-07-01

    In this project we intend to study a novel process concept, i.e, the use of ceramic membranes reactors in upgrading of coal derived liquids. Membrane reactors have been used in a number of catalytic reaction processes in order to overcome the limitations on conversion imposed by thermodynamic equilibrium. They have, furthermore, the inherent capability for combining reaction and separation in a single step. Thus they offer promise for improving and optimizing yield, selectivity and performance of processes involving complex liquids, as those typically found in coal liquid upgrading. Ceramic membranes are a new class of materials, which have shown promise in a variety of industrial applications. Their mechanical and chemical stability coupled with a wide range of operating temperatures and pressures make them suitable for environments found in coal liquid upgrading. In this project we will evaluate the performance of Sol-Gel alumina membranes in coal liquid upgrading processes under realistic temperature and pressure conditions and investigate the feasibility of using such membranes in a membrane reactor based coal liquid upgrading process. In addition, the development of novel ceramic membranes with enhanced catalytic activity for coal-liquid upgrading applications, such as carbon-coated alumina membranes, will be also investigated.

  15. 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

    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...... spectroscopic properties of DOM....

  16. Liquid Chromatographic Determination of Linagliptin in Bulk, in Plasma and in its Pharmaceutical Preparation

    OpenAIRE

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

    2012-01-01

    In this work, two reversed-phase liquid chromatographic (RP-LC) methods have been developed for the determination of linagliptin (LNG) 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. Two detection techniques have been applied either UV detection at 299 nm in the first method or fluorometric detection at 239 nm for excitation and 355 nm for emission in the second method. Chromato...

  17. 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...

  18. A comprehensive study into fouling properties of extracellular polymeric substance (EPS) extracted from bulk sludge and cake sludge in a mesophilic anaerobic membrane bioreactor.

    Science.gov (United States)

    Ding, Yi; Tian, Yu; Li, Zhipeng; Zuo, Wei; Zhang, Jun

    2015-09-01

    This study focused on the fouling behaviors of extracellular polymeric substances (EPS) in a mesophilic anaerobic membrane bioreactor (AnMBR) to obtain the relations of EPS specific constituents with membrane fouling. It was found that for the EPS extracted from bulk sludge, the LB-EPS induced the largest flux decline; however, for EPS extracted from cake sludge, the S-EPS caused the highest flux decline. The preferential rejection fraction by membrane further confirmed that the greater flux decline was exhibited with the higher percent rejection of EPS fractions. The adhesion and cohesion interactions of EPS fractions and membranes could explain the different rejection rates of the EPS components. The structural characteristics analysis indicated that the fouling layers of different EPS fractions with the greater loss of filterability had the smaller porosity. Further investigations demonstrated that these changes could be attributed to the different content of HPO-N in EPS fractions. PMID:26022972

  19. The extraction of uranium from wet process phosphoric acid using a liquid surfactant membrane system

    International Nuclear Information System (INIS)

    A liquid membrane extraction process is examined for the extraction of uranium from wet process phosphoric acid. Uranium is present in the acid in concentrations up to 100 ppm which in principle makes it ideal for treatment with a membrane process. The membrane system studied is based on extraction using DEHPA-TOPO reagents which are contained within the organic phase of a water in oil emulsion. Formulations of the emulsion membrane system have been studied, the limitations of acid temperature, P2O5 concentration and solid dispersed impurities in the acid have been studied in laboratory batch experiments and in a continuous pilot plant unit capable of treating 5l of concentrated acid per minute. Data from the pilot plant work has been used to develop a flowsheet for a commercial unit based on this process. (author)

  20. 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.

  1. 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%.

  2. 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 (20ns) or a femtosecond (90fs) 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. PMID:26866890

  3. An Electrochemical Sensing Platform Based on Liquid-Liquid Microinterface Arrays Formed in Laser-Ablated Glass Membranes.

    Science.gov (United States)

    Alvarez de Eulate, Eva; Strutwolf, Jörg; Liu, Yang; O'Donnell, Kane; Arrigan, Damien W M

    2016-03-01

    Arrays of microscale interfaces between two immiscible electrolyte solutions (μITIES) were formed using glass membranes perforated with microscale pores by laser ablation. Square arrays of 100 micropores in 130 μm thick borosilicate glass coverslips were functionalized with trichloro(1H,1H,2H,2H-perfluorooctyl)silane on one side, to render the surface hydrophobic and support the formation of aqueous-organic liquid-liquid microinterfaces. The pores show a conical shape, with larger radii at the laser entry side (26.5 μm) than at the laser exit side (11.5 μm). The modified surfaces were characterized by contact angle measurements and X-ray photoelectron spectroscopy. The organic phase was placed on the hydrophobic side of the membrane, enabling the array of μITIES to be located at either the wider or narrower pore mouth. The electrochemical behavior of the μITIES arrays were investigated by tetrapropylammonium ion transfer across water-1,6-dichlorohexane interfaces together with finite element computational simulations. The data suggest that the smallest microinterfaces (formed on the laser exit side) were located at the mouth of the pore in hemispherical geometry, while the larger microinterfaces (formed on the laser entry side) were flatter in shape but exhibited more instability due to the significant roughness of the glass around the pore mouths. The glass membrane-supported μITIES arrays presented here provide a new platform for chemical and biochemical sensing systems. PMID:26853853

  4. 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

  5. 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. PMID:26666712

  6. Synthesis and characterization of ionic liquid (EMImBF4)/Li+ - chitosan membranes for ion battery

    International Nuclear Information System (INIS)

    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+ 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 × 10−2 S cm−1 for chitosan to 1.30 × 10−2 S cm−1 for chitosan with EMImBF4/Li+, and this result was supported by analysis the surface morphology (SEM)

  7. Synthesis and characterization of ionic liquid (EMImBF4)/Li+ - chitosan membranes for ion battery

    Science.gov (United States)

    Pasaribu, Marvin H.; Arcana, I. Made; Wahyuningrum, Deana

    2015-09-01

    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+ 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 × 10-2 S cm- 1 for chitosan to 1.30 × 10-2 S cm-1 for chitosan with EMImBF4/Li+, and this result was supported by analysis the surface morphology (SEM).

  8. Stir-membrane solid-liquid-liquid microextraction for the determination of parabens in human breast milk samples by ultra high performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Rodríguez-Gómez, Rocío; Roldán-Pijuán, Mercedes; Lucena, Rafael; Cárdenas, Soledad; Zafra-Gómez, Alberto; Ballesteros, Oscar; Navalón, Alberto; Valcárcel, Miguel

    2014-08-01

    In this article, stir-membrane solid-liquid-liquid microextraction (SM-SLLME) is tailored for the analysis of solid matrices and it has been evaluated for the determination of parabens in l breast milk samples. A three-phase microextraction mode was used for the extraction of the target compounds taking advantage of their acid-base properties. The unit allows the simultaneous extraction of the target compounds from the solid sample to an organic media and the subsequent transference of the analytes to an aqueous acceptor phase. The method includes the identification and quantification of the analytes by ultra high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS). All the variables involved in the extraction procedure have been accurately studied and optimized. The analytes were detected and quantified using a triple quadrupole mass spectrometer (QqQ). The selection of two specific fragmentation transitions for each compound allowed simultaneous quantification and identification. The method has been analytically characterized on the basis of its linearity, sensitivity and precision. Limits of detection ranged from 0.1 to 0.2ngmL(-1) with precision better than 8%, (expressed as relative standard deviation). Relative recoveries were in the range from 91 to 106% which demonstrated the applicability of the stir-membrane solid-liquid-liquid microextraction for the proposed analytical problem. Moreover, the method has been satisfactorily applied for the determination of parabens in lyophilized breast milk samples from 10 randomly selected individuals. PMID:24935266

  9. Europium extraction with supported liquid membranes (SLM's) using new resorcinarene cavitand CMPO ligands

    International Nuclear Information System (INIS)

    In thus paper is presented a new type of resorcinarene cavitand based ligands, functionalized with CMP(O)-ligating moieties (CMP(O) carbamoylmethylphosphoryl). The steric pre-organization of four CMP(O) moieties on the macrocyclic resorcinarene cavitand frame highly improves the efficiency and selectivity of the metal extraction processes. The new CMP(O) resorcinarene ligands are very effective europium extractants (europium was used as a general trivalent actinides). Europium could be quantitatively removed from acidic nitrate solutions applying the ligands in Supported Liquid Membrane (SLM) extractions. In SLM extractions two aqueous phases (the source and receiving phase) are separated by a porous polymeric membrane. Within the pores of the membrane an organic liquid is 'immobilized' (n-nitrophenyloctyl ether; NPOE). The NPOE phase contains the ligand which provides the transport of the cation from the source to the receiving phase. Applying a source phase a high concentration salting agent (LiNO3) provides a driving force for the 'uphill' transport of europium, allowing quantitative extraction. The concentration of europium in the source phase gradually reaches zero after approximately 8 hours. On the other hand, the concentration of europium in the receiving phase increases, till the phase contains the total content europium. From the difference between the amount of europium in both aqueous phases (As + Ar = Atot) and the total content (Amax) the concentration of europium in the membrane can be calculated. Elucidation of the extraction and membrane transport mechanisms are currently under investigation. 2 figs., 3 refs

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

    International Nuclear Information System (INIS)

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

  11. A General Strategy for the Separation of Immiscible Organic Liquids by Manipulating the Surface Tensions of Nanofibrous Membranes.

    Science.gov (United States)

    Wang, Li; Zhao, Yong; Tian, Ye; Jiang, Lei

    2015-12-01

    Oil/water separation membranes with different wettability towards water are attractive for their economic efficiency and convenience. The key factor for the separation process is the roughness-enhanced wettability of membranes based on the intrinsic wetting threshold (IWT) of water, that is, the limitation of the wettability caused by hydrophobicity and hydrophilicity. However, the separation of organic liquids (OLs) remains a challenge. Herein, we manipulate the surface tensions of nanofibrous membranes to lie between the IWTs of the two OLs to be separated so that the nanofibrous membranes can be endowed with superlyophobicity and superlyophilicity for the two liquids, and thus lead to successful separation. Our investigations provide a general strategy to separate any immiscible liquids efficiently, and may lead to the development of membranes with a large capacity, high flux, and high selectivity for organic reactions or liquid extraction in chemical engineering. PMID:26492856

  12. 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.

  13. 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.

  14. 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.

  15. Concentration of europium(III) with supported liquid membrane containing a xylene solution of di-2-ethyihexyl phosphoric acid

    Science.gov (United States)

    Nishiki, Tadaaki; Bautista, Renato G.

    1983-03-01

    The mechanism of europium transport through a supported liquid membrane is presented. The membrane consisted of a Teflon filter membrane with xylene solution of di-2-ethylhexyl phosphoric acid (HDEHP) as a mobile carrier held within the pores by capillary forces. Interposing the liquid membrane between two aqueous solutions of different pH, europium was transported and concentrated from the high pH solution to the low pH solution across the liquid membrane. The experiments were carried out to investigate the effects of the concentration of europium in the aqueous phase and HDEHP concentration in the membrane solution on the permeation rates of europium. The experimental results have been compared with a transport model for concentrating europium across the liquid membrane. The permeation rates of europium can be explained approximately by the diffusion process of the complex formed between europium ion and HDEHP at the membrane interface through the membrane in addition to the diffusion process of europium in the aqueous film adjacent to the membrane interface.

  16. Free liquid membranes - a novel progressive concept of phase interfaces for electrically enhanced microextraction techniques

    Czech Academy of Sciences Publication Activity Database

    Kubáň, Pavel; Boček, Petr

    Grupo VLS Print Solution, 2014 - (Guzman, N.; Taveres, M.). s. 64-64 [ITP & LACE 2014. International Symposium on Electro- and Liquid Phase-Separation Techniques /21./ and Latin-American Symposium on Biotechnology, Biomedical, Biopharmaceutical, and Industrial Applications of Capillary Electrophoresis and Microchip Technology /20./. 04.10.2014-08.10.2014, Natal] R&D Projects: GA ČR(CZ) GA13-05762S Institutional support: RVO:68081715 Keywords : free liquid membranes * microextractions * complex samples Subject RIV: CB - Analytical Chemistry, Separation

  17. 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.

  18. Treatment of liquid radioactive waste by membranes techniques - Needs and future trends

    International Nuclear Information System (INIS)

    The nuclear industry generates a broad spectrum of low and intermediate level liquid radioactive wastes (LRWs). The treatment methods used for liquid radioactive waste are related to the conventional processes used for the treatment of the industrial wastewater, like chemical treatment, adsorption, filtration and ionic exchange. The use of such of techniques is limited due to their decreased capacity to remove the radioactive contaminants, the increased operational costs (e.g. evaporation) or the yielding potential for significant quantities of secondary solid waste. After development of suitable membrane materials and their long-term verification in conventional water purification fields, the membrane processes have been adopted by the nuclear industry as a viable alternative for the treatment of LRWs. The most utilized processes in the field of water and wastewater treatment are those utilizing pressure gradient as the process driving force. These processes include reverse osmosis, nanofiltration, ultrafiltration and microfiltration, allowing the selective removing both dissolved and particulate contaminants. (authors)

  19. Application of Europium(III) extraction with organophosphinic acid to liquid membrane transport

    International Nuclear Information System (INIS)

    The extraction behaviour of Eu(III) has been studied using di(2.4,4-trimethylpentyl)phosphinic acid (DTMPPA, HA) in kerosene. Europium was extracted as Eu(HA2)3 with the extraction constant of 2.0 x 10-3. This extraction system was applied to the transport of Eu(III) across a DTMPPA liquid membrane supported on porous polytetrafluoroethylene. Europium was quantitatively moved through the liquid membrane containing 0.1M(HA)2 as a mobile carrier from the feed solution of pH above 3 into the product solution of 0.1M HNO3, yielding a concentration factor of ten. The transport rate increased with increasing pH and DTMPPA concentration. (author) 14 refs.; 9 figs.; 1 tab

  20. Hollow-fiber supported liquid membrane (HFSLM) for the separation of lanthanides and actinides

    International Nuclear Information System (INIS)

    The transport behavior of Nd(III) was investigated using hollow-fiber supported liquid membranes (HFSLM) from an acidic feed solution using N,N,N',N'-tetraoctyl-diglycolamide (TODGA) in normal paraffinic hydrocarbon (NPH) as the carrier. Near quantitative transport (>99%) of Nd(III) from 500 mL of feed containing 1 g/L Nd in 3.5 M HNO3 was possible in about 45 minutes. Quantitative transport time increased when the volume or Nd(III ) concentration in the feed was increased. The liquid membrane had excellent stability as indicated by eight consecutive runs that gave consistent transport rates. The HFSLM data using Cyanex- 301 in n-dodecane as carrier extractant for the lanthanide-actinide separation with the feed solution 1 M NaNO3 at pH 3.5 and stripping solution 0.01 M EDTA at a pH 3.5 were promising. (authors)

  1. Theoretical and Experimental Mass Transfer Coefficients of Permeating Components in Supported Ionic Liquid Membranes

    Czech Academy of Sciences Publication Activity Database

    Izák, Pavel; Kárászová, Magda; Šimčík, Miroslav; Friess, K.; Sedláková, Zuzana; Růžička, Marek; Šolcová, Olga

    Bratislava: AXIMA Graphics Design & Printing Services, 2014, s. 91 ISBN 978-80-89475-13-1. [International Conference of Slovak Society of Chemical Engineering /41./. Tatranské Matliare (SK), 26.05.2014-30.05.2014] R&D Projects: GA TA ČR TE01020080; GA ČR GA14-12695S Institutional support: RVO:67985858 Keywords : ionic liquid membrane * transport properties * trafer coefficients Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  2. Mathematical Balance of Ethanol Vapour Permeation Flux in Ionic Liquid Membrane

    Czech Academy of Sciences Publication Activity Database

    Sedláková, Zuzana; Morávková, Lenka; Vejražka, Jiří; Izák, Pavel

    Praha : Česká společnost průmyslové chemie, 2015, s. 28 /p50./. ISBN 978-80-86238-73-9. [mezinárodní chemicko-technologická konference (ICCT 2015) /3./. Mikulov (CZ), 13.04.2015-15.04.2015] R&D Projects: GA MŠk(CZ) LD14094 Institutional support: RVO:67985858 Keywords : ionoc liquid membrane * ethanol vapour lux * mathematical balance Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  3. 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.

  4. Application of Liquid Emulsion Membrane Technique for the Removal of As(V) from Aqueous Solutions

    Science.gov (United States)

    Binnal, Prakash; Hiremath, Poornima G.

    2012-08-01

    Liquid emulsion membrane technique was used to remove As(V) from synthetic aqueous solutions. The emulsion was composed of Aliquat 336 as an extractant, commercial kerosene as a diluent and Span 80 (Sorbiton monooleate) as an emulsifying agent. Different types of internal phases were used, namely, sodium hydroxide, sodium carbonate, ammonium bicarbonate, sodium sulphate and sodium chloride. The effect of process parameters affecting extraction efficiency, such as, initial concentration of As(V) in feed solution, pH of feed solution, concentrations of Aliquat 336 and Span 80 in membrane phase, volume ratio of stripping phase to membrane phase, concentration of internal phase, type of internal phase, volume ratio of emulsion to feed, agitation speed during extraction and time of extraction was investigated. The optimum conditions for the extraction were determined. A maximum As(V) removal rate of 97.8 was observed under optimum conditions.

  5. Small atom diffusion in the glassy and supercooled liquid states of bulk amorphous ZrTiCuNiBe alloys

    International Nuclear Information System (INIS)

    New bulk metallic ZrTiCuNiBe glass forming alloys exhibit an excellent stability over a large supercooled liquid region and offer the opportunity to investigate atomic transport in the supercooled liquid state. We present measurements of atomic diffusion of beryllium in Zr41.2Ti13.8Cu12.5Ni10Be22.5 and Zr46.7Ti8.3Cu7.5Ni10Be27.5 in the temperature range between 530 K and 710 K. Below the glass transition temperature, Tg∼625 K, the data suggest a single atomic jump diffusion behavior of Be with a migration enthalpy of about 1 eV/atom in both alloys. Below Tg, Be diffusivity in Zr46.7Ti8.3Cu7.5Ni10Be27.5 is by one order of magnitude higher than in Zr41.2Ti13.8Cu12.5Ni10Be27.5 which can be explained by a larger fraction of free volume in this alloy. Above the glass transition the temperature dependence of Be diffusivity increases in both alloys, leading to apparent activation energies of 4.5 eV/atom in Zr41.2Ti13.8Cu12.5Ni10Be22.5 and 1.9 eV/atom in Zr46.7Ti8.3Cu7.5Ni10Be27.5. By taking into account the change in configurational entropy due to the glass transition, we explain the mechanism for diffusion of Be in the supercooled liquid states of the ZrTiNiCuBe alloys by single atomic jumps in a continously changing configuration of neighboring atoms. The corresponding migration enthalpies are the same as in the solid states, and the larger activation energies above Tg are mimiced by the increase of configurational entropy with temperature which is smaller in Zr46.7Ti8.3Cu7.5Ni10Be27.5 than in Zr41.2Ti13.8Cu12.5Ni10Be22.5. A comparison of Be diffusivity and viscosity of Zr46.7Ti8.3Cu7.5Ni10Be27.5 above Tg reveals a breakdown of the Stokes-Einstein relation, indicating cooperative processes in the supercooled liquid state. (orig.)

  6. 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

  7. Correcting the wavefront aberration of membrane mirror based on liquid crystal spatial light modulator

    Science.gov (United States)

    Yang, Bin; Wei, Yin; Chen, Xinhua; Tang, Minxue

    2014-11-01

    Membrane mirror with flexible polymer film substrate is a new-concept ultra lightweight mirror for space applications. Compared with traditional mirrors, membrane mirror has the advantages of lightweight, folding and deployable, low cost and etc. Due to the surface shape of flexible membrane mirror is easy to deviate from the design surface shape, it will bring wavefront aberration to the optical system. In order to solve this problem, a method of membrane mirror wavefront aberration correction based on the liquid crystal spatial light modulator (LCSLM) will be studied in this paper. The wavefront aberration correction principle of LCSLM is described and the phase modulation property of a LCSLM is measured and analyzed firstly. Then the membrane mirror wavefront aberration correction system is designed and established according to the optical properties of a membrane mirror. The LCSLM and a Hartmann-Shack sensor are used as a wavefront corrector and a wavefront detector, respectively. The detected wavefront aberration is calculated and converted into voltage value on LCSLM for the mirror wavefront aberration correction by programming in Matlab. When in experiment, the wavefront aberration of a glass plane mirror with a diameter of 70 mm is measured and corrected for verifying the feasibility of the experiment system and the correctness of the program. The PV value and RMS value of distorted wavefront are reduced and near diffraction limited optical performance is achieved. On this basis, the wavefront aberration of the aperture center Φ25 mm in a membrane mirror with a diameter of 200 mm is corrected and the errors are analyzed. It provides a means of correcting the wavefront aberration of membrane mirror.

  8. 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.

  9. To Polarize or Not to Polarize? Charge-on-Spring versus KBFF Models for Water and Methanol Bulk and Vapor-Liquid Interfacial Mixtures.

    Science.gov (United States)

    Ploetz, Elizabeth A; Rustenburg, Ariën S; Geerke, Daan P; Smith, Paul E

    2016-05-10

    Simulations of water and methanol mixtures using polarizable force fields (FFs) for methanol (COS/M and CPC) and water (COS/G2) were performed and compared to experiment and also to a nonpolarizable methanol (KBFF) model with SPC/E water in an effort to quantify the importance of explicit electronic polarization effects in bulk liquid mixtures and vapor-liquid interfaces. The bulk liquid mixture properties studied included the center of mass radial distribution functions, Kirkwood-Buff integrals (KBIs), volumetric properties, isothermal compressibility, enthalpy of mixing, dielectric constant, and diffusion coefficients. The vapor-liquid interface properties investigated included the relative surface probability distributions, surface tension, excess surface adsorption, preferred surface molecule orientations, and the surface dipole. None of the three FFs tested here was clearly superior for all of the properties examined. All the force fields typically reproduced the correct trends with composition for both the bulk and interfacial system properties; the differences between the force fields were primarily quantitative. The overall results suggest that the polarizable FFs are not, at the present stage of development, inherently better able to reproduce the studied bulk and interfacial properties-despite the added degree of explicit transferability that is, by definition, built into the polarizable models. Indeed, the specific parametrization of the FF appears to be just as important as the class of FF. PMID:27045390

  10. Search for a new greener technology for separation of NCA 97Ru from bulk Nb: ionic liquid based aqueous biphasic system

    International Nuclear Information System (INIS)

    Ionic-liquid (IL) based aqueous biphasic system was developed for the separation of no-carrier-added (NCA) 97Ru from bulk niobium target for the first time as greener separation technology. Room temperature ionic liquid, 1-butyl-3-methylimidazolium Chloride ((Bmim)Cl) against K2HPO4 as salt rich phase was employed to construct this IL-ABS system. In the typical experimental condition, 50 % NCA 97Ru was extracted into the ionic liquid phase without any contamination of Nb, with a separation factor of 5.3x103. (author)

  11. Effect of complexing agent on transport of lanthanoid elements across versatic acid liquid membrane

    International Nuclear Information System (INIS)

    Transport of several trivalent lanthanoids (La, Nd, Sm, Eu, Tb, Tm, and Lu) was examined across a supported liquid membrane (SLM) containing Versatic 10 (VA10) in kerosene. Lanthanoids in the feed solution can be effectively transported and concentrated into the product solution. Separation factors obtained from the transport rates for lighter lanthanoids were larger than those for heavier lanthanoids, in agreement with the result on the distribution ratios in liquid-liquid extraction. The separation factors for heavier lanthanoids were enhanced by the addition of citrate to the feed solution. The transport rate was controlled by the extraction process from the feed solution to the SLM and the diffusion process of lanthanoid VA10 complexes in SLM

  12. Development of a Supported Emulsion Liquid Membrane System for Propionic Acid Separation in a Microgravity Environment

    Science.gov (United States)

    Li, Jin; Hu, Shih-Yao B.; Wiencek, John M.

    2001-01-01

    Perstractive fermentation is a good way to increase the productivity of bioreactors. Using Propionibacteria as the model system, the feasibility of using supported emulsion liquid membrane (SELM) for perstractive fermentation is assessed in this study. Five industrial solvents were considered as the solvent for preparing the SELM. The more polar a solvent is, the higher the partition coefficient. However, toxicity of a solvent also increases with its polarity. CO-1055 (industrial decanol/octanol blend) has the highest partition coefficient toward propionic acid among the solvents that has no molecular toxicity toward Propionibacteria. A preliminary extraction study was conducted using tetradecane as solvent in a hydrophobic hollow fiber contactor. The result confirmed that SELM eliminates the equilibrium limitation of conventional liquid-liquid extraction, and allows the use of a non-toxic solvent with low partition coefficient.

  13. Studies on yttrium and neodymium transportation behaviour using hollow fibre supported liquid membrane

    International Nuclear Information System (INIS)

    Preliminary studies on rare earths transportation using Hollow Fibre Supported Liquid Membrane (HFSLM) were carried out. High purity yttrium finds applications in phosphors, super conductors, 90Y in radiopharmaceutical application, etc while neodymium finds use in permanent magnets, lasers, etc. Transportation studies were conducted using HFSLM Module of 'Liquicel X50 2.5x8 membrane contactor' in a continuous operation mode. The material of construction of membrane was polypropylene having 9950 fibres each of length 15 cm. Initially, 1 M 2-ethyl hexyl, 2-ethyl hexyl phosphonic acid (PC 88A) was loaded on the membrane under pressure. The membrane was washed with water both on the shell side and tube side to remove excess solvent. Feed comprising of 6.7 g/l each of Y and Nd in nitrate medium having feed acidity of 0.5 M HNO3 was passed at a rate of 80 ml/min (tube side) in separate runs. On the other side (shell), strip comprising of 3 M HNO3 was passed at the same flow rate. The run was made for 6 hours and samples were collected at fixed time intervals. The samples were analyzed for metal content using ICP-AES

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

    Directory of Open Access Journals (Sweden)

    Marcos Alexandre Gelesky

    2014-01-01

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

  15. Supported liquid membrane system for Cr(III) separation from Cr(III)/Cr(VI) mixtures.

    Science.gov (United States)

    Religa, P; Rajewski, J; Gierycz, P; Swietlik, R

    2014-01-01

    This paper presents the results of analyses of the chromium(III) transport process from mixtures of Cr(III)/Cr(VI) ions using supported liquid membranes (SLM), in which dinonylnaphthalene sulfonic acid (DNNSA) and di(2-ethylhexyl) phosphoric acid (D2EHPA) were used as carriers. In both cases the membrane worked as a selective barrier for Cr(VI) ions. The increase in both the time of Cr(VI) ions-carrier interaction and the Cr(VI) concentration in the feed phase negatively influenced the Cr(III) separation. The polarizing layer consisting of Cr(VI) ions prevents the access of Cr(III) ions to the inter phase surface and leads to the deactivation of the carrier, which is the result of the strong oxidation properties of Cr(VI) ions. These factors meant that, in the case of the membrane with DNNSA, the membrane could not be used for the effective separation of Cr(III) from the Cr(III)/Cr(VI) mixture. On the other hand, the membrane with D2EHPA can be used for fast and efficient transport of Cr(III) ions, but only for strictly defined process parameters, i.e. where the level of chromium(VI) concentration is below 10(-3)M and with intensive feed phase mixing. PMID:24960010

  16. The Liquid Sensor Using Thin Film Bulk Acoustic Resonator with C-Axis Tilted AlN Films

    Directory of Open Access Journals (Sweden)

    Ying-Chung Chen

    2013-01-01

    Full Text Available Dual-mode thin film bulk acoustic resonator (TFBAR devices are fabricated with c-axis tilted AlN films. To fabricate dual-mode TFBAR devices, the off-axis RF magnetron sputtering method for the growth of tilted piezoelectric AlN thin films is adopted. In this report, the AlN thin films are deposited with tilting angles of 15° and 23°. The frequency response of the TFBAR device with 23° tilted AlN thin film is measured to reveal its ability to provide dual-mode resonance. The sensitivities of the longitudinal and shear modes to mass loading are calculated to be 2295 Hz cm2/ng and 1363 Hz cm2/ng with the mechanical quality factors of 480 and 287, respectively. The sensitivities of the longitudinal and shear modes are calculated to be 0 and 15 Hz cm2/μg for liquid loading.

  17. 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.

  18. 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. PMID:27046045

  19. 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).

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

    International Nuclear Information System (INIS)

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

  1. Enhancement of the Gas Separation Performance of Polymeric Thin Film Composite Membranes by Conditioning with Room Temperature Ionic Liquids

    Czech Academy of Sciences Publication Activity Database

    Jansen, J.C.; Esposito, E.; Tasselli, F.; Bernardo, P.; Curcio, S.; Sedláková, Zuzana; Izák, Pavel; Clarizia, G.

    Istanbul : -, 2014. ISBN N. [International Conference on Ionic Liquids in Separation and Purification Technology /2./. Toronto (CA), 29.06.2014-02.07.2014] Grant ostatní: PONRC(IT) PON01_01840 Institutional support: RVO:67985858 Keywords : fibre configuration * ionic liquid * membrane separation methods Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  2. 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).

  3. Fabrication of protic ionic liquid/sulfonated polyimide composite membranes for non-humidified fuel cells

    Science.gov (United States)

    Lee, Seung-Yul; Yasuda, Tomohiro; Watanabe, Masayoshi

    We have demonstrated that a protic ionic liquid, diethylmethylammonium trifluoromethanesulfonate ([dema][TfO]) functions as a proton conductor and is suitable for use as an electrolyte in H 2/O 2 fuel cells, which can be operated at temperatures higher than 100 °C under non-humidified conditions. In this study, in order to fabricate a polymer electrolyte fuel cell, matrix polymers for [dema][TfO] are explored and sulfonated polyimides (SPI), in which the sulfonic acid groups are in diethylmethylammonium form, are found to be highly compatible with [dema][TfO]. Polymer electrolyte membranes for non-humidified fuel cells are prepared by the solvent casting method using SPI and [dema][TfO]. The SPI, with an ion exchange capacity of 2.27 meq g -1, can retain four times its own weight of [dema][TfO] and produces uniform, tough, and transparent composite membranes. The composite membranes have good thermal stability (>300 °C) and ionic conductivity (>10 -2 S cm -1 at 120 °C when the [dema][TfO] content is higher than 67 wt%) under anhydrous conditions. In the H 2/O 2 fuel cell operation using a composite membrane without humidification, a current density higher than 240 mA cm -2 is achieved with a maximum power density of 100 mW cm -2 at 80 °C.

  4. Monitoring Ion Activities In and Around Cells Using Ion-Selective Liquid-Membrane Microelectrodes

    Directory of Open Access Journals (Sweden)

    Mark D. Parker

    2013-01-01

    Full Text Available Determining the effective concentration (i.e., activity of ions in and around living cells is important to our understanding of the contribution of those ions to cellular function. Moreover, monitoring changes in ion activities in and around cells is informative about the actions of the transporters and/or channels operating in the cell membrane. The activity of an ion can be measured using a glass microelectrode that includes in its tip a liquid-membrane doped with an ion-selective ionophore. Because these electrodes can be fabricated with tip diameters that are less than 1 μm, they can be used to impale single cells in order to monitor the activities of intracellular ions. This review summarizes the history, theory, and practice of ion-selective microelectrode use and brings together a number of classic and recent examples of their usefulness in the realm of physiological study.

  5. 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.

  6. Lyotropic Liquid Crystalline Cubic Phases as Versatile Host Matrices for Membrane-Bound Enzymes.

    Science.gov (United States)

    Sun, Wenjie; Vallooran, Jijo J; Fong, Wye-Khay; Mezzenga, Raffaele

    2016-04-21

    Lyotropic liquid crystalline cubic mesophases can function as host matrices for enzymes because of their biomimetic structural characteristics, optical transparency, and capability to coexist with water. This study demonstrates that the in meso immobilized membrane-bound enzyme d-fructose dehydrogenase (FDH) preserves its full activity, follows ideal Michaelis-Menten kinetics, and shows improved stability compared to its behavior in solution. Even after 5 days, the immobilized FDH retained its full activity in meso, whereas a model hydrophilic enzyme, horseradish peroxidase, maintained only 21% of its original activity. We reason that the lipidic bilayers in the three-dimensional structures of cubic mesophases provide an ideal environment for the reconstitution of a membrane-bound enzyme. The preserved activity, long-term stability, and reusability demonstrate that these hybrid nanomaterials are ideal matrices for biosensing and biocatalytic fuel cell applications. PMID:27050734

  7. Effect of vapor- and liquid-phase radiation grafting on water permeability of porous hollow-fiber membrane

    International Nuclear Information System (INIS)

    Effect of the radiation-induced graft polymerization of monomers in vapor and liquid phases to the hollow-fiber membrane microfilter, made of porous high density polyethylene, upon the permeability of water has been studied. Determination of the flux of hollow-fiber membranes prepared by the graft polymerization of acrylonitrile, vinyl acetate, styrene, or acrylic acid revealed that the membranes prepared by vapor-phase grafting had a higher flux than those prepared by liquid-phase grafting. The measurement of pore volume and dimensional change revealed that hollow-fiber membrane grafted in vapor phase swells to larger extent. Cyano group of acrylonitrile and acetoxyl group of vinyl acetate, grafted to hollow-fiber membrane were converted to amide oxime and alcoholic hydroxyl group, respectively by the chemical modification. The flux of these functionalized membranes were determined and it is found that the functionalized membranes derived from vapor-phase grafted membrane had higher water permeability than those derived from liquid-phase grafted ones. (author)

  8. Rate and mechanism of facilitated americium(III) transport through a supported liquid membrane containing a bifunctional organophosphorus mobile carrier

    International Nuclear Information System (INIS)

    The facilitated transport of Am(III) from aqueous nitrate solutions to formic acid aqueous solutions through a supported liquid membrane (SLM) is described. The supported liquid membrane consists of a solution of a new (carbamoylmethyl)phosphine oxide in diethylbenzene (DEB) absorbed into a 48 μm thick microporous polypropylene film. The transport mechanism consists of a diffusion process through an aqueous diffusion film, a fast interfacial chemical reaction, and diffusion through the membrane itself. Equations describing the rate of transport are derived. They correlate the membrane permeability coefficient to diffusional parameters and to the chemical composition of the system. Different rate-controlling processes are shown to control the membrane permeability when the composition of the system is varied and as long as the transport occurs. The experimental data are quantitatively explained with the derived equations. The diffusion coefficient of the permeating species and the equilibrium constant of the fast interfacial reactions are evaluated. 13 figures, 1 table

  9. Hollow fibre liquid membranes: a novel approach for nuclear waste remediation

    International Nuclear Information System (INIS)

    Liquid membrane separations using hollow fiber contactors are finding increasing applications in diverse areas including metal ion separations. This technique offers the advantages of active transport, possible usage of exotic carriers, easy scale-up, low energy requirements, low capital and operating costs, etc. At Radiochemistry Division, hollow fiber based separation processes have been developed for actinide partitioning, lanthanide/actinide separation, Sr/Y separation, recovery of radio-cesium and plutonium from various wastes. The physical, chemical and radiolytic stability of the HFSLM system has been investigated. Non-dispersive solvent extraction using hollow fiber contactors has also been employed for the extraction of actinides and lanthanides. (author)

  10. Influence of Ionic Liquid Content on Transport Properties of Dense Polymeric Membranes.

    Czech Academy of Sciences Publication Activity Database

    Izák, Pavel; Kačírková, Marie; Bernardo, P.; Jansen, J.C.

    Poznań: Poznan Science and Technology Park, 2016, s. 38. ISBN N. [COST CM1206 Meeting: WG1 and WG4 Workshop and MC Meeting: Advances on Green Technologies . Poznań (PL), 19.04.2016-20.04.2016] Institutional support: RVO:67985858 Keywords : polymeric membranes * ionic liquid * dsc analysis Subject RIV: CI - Industrial Chemistry, Chemical Engineering https://drive.google.com/file/d/0ByvzfYWTeIHMVkcyZ1J4VndTQU0/view?pref=2&pli=1

  11. Comparison of Theoretical and Experimental Mass Transfer Coefficients of Gases in Supported Ionic Liquid Membranes

    Czech Academy of Sciences Publication Activity Database

    Kárászová, Magda; Šimčík, Miroslav; Friess, K.; Randová, A.; Jansen, J. C.; Růžička, Marek; Sedláková, Zuzana; Izák, Pavel

    2013-01-01

    Roč. 118, 30 OCT (2013), s. 255-263. ISSN 1383-5866 R&D Projects: GA ČR GAP106/10/1194; GA MŠk(CZ) 7C11009 Grant ostatní: RFCS(XE) RFCR-CT-2010-00009; INP(IT) PON01_01840; HA MŠk(CZ) CZ.1.05/2.1.00/03.0071 Institutional support: RVO:67985858 Keywords : biogas purification * supported ionic liquid membranes * mass transfer coefficients Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 3.065, year: 2013

  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. PMID:25554341

  13. Comparison of Theoretical and Experimental Mass TransferCoefficients of Gases in Supported Ionic Liquid Membranes.

    Czech Academy of Sciences Publication Activity Database

    Kárászová, Magda; Šimčík, Miroslav; Jansen, J.; Sedláková, Zuzana; Růžička, Marek; Izák, Pavel

    Bratislava : Slovak Society of Chemical Engineering, 2013 - (Markoš, J.), s. 139 ISBN 978-80-89475-09-4. [International Conference of Slovak Society of Chemical Engineering /40./. Tatranské Matliare (SK), 27.05.2013-31.05.2013] R&D Projects: GA ČR GAP106/10/1194; GA MŠk(CZ) 7C11009 Grant ostatní: RFCS(XE) RFCR-CT-2010-00009 Institutional support: RVO:67985858 Keywords : biogas purification * supported ionic liquid membranes * permeability Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  14. Carrier-mediated transport of rare earth elements through liquid membranes Pt. 4

    International Nuclear Information System (INIS)

    Transport of tervalent REEs - Sc, Y, Ce, Eu, Gd, Tm, Yb - from nitrate medium through a liquid membrane containing TBP in n-dodecane, impregnated on a flat-sheet nucleoporous support, has been studied as a function of time and initial metal concentration, salting-out agent concentration and pH of the feed phase. Influences of various complexing agents dissolved in the strip phase was investigated, too. Adding a suitable amount of EDTA into the feed phase, separation of binary mixtures of REEs was experimentally achieved. (author) 15 refs.; 8 figs.; 7 tabs

  15. The device for ultra-filtration of liquid radioactive waste using the track membranes

    International Nuclear Information System (INIS)

    Full text: The ultra-filtration device was designed and fabricated intended for consistent selective treatment on the track membrance of radionuclide waste from the WWR-K reactor from the main radionuclide contaminants : 137 Cs, 60Co and 90Sr. In order to maintain the productivity of the device for the long time, the device includes the system of periodical short-term washing of membranes by the reverse flow of the purified liquid. The advantage of this device is the significant weight reduction of the products to be disposed as compared with the known technologies of LRW purification

  16. Hollow fiber supported liquid membrane technology: possible applications in the radioactive waste management

    International Nuclear Information System (INIS)

    Hollow fiber supported liquid membrane (HFSLM) technology development work was carried out at Radiochemistry Division, BARC for possible applications in the back end of the nuclear fuel cycle. Some of the studies carried out included 'actinide partitioning' using TODGA, lanthanide - actinide separation using Cyanex-301 and Cs recovery from waste using Calix-crown-6. The physical stability of HFSLM was reasonably good during continuous operation for over 120 h. Radiolytic stability of hollow fibre module up to 500 KGy dose was also satisfactory. (author)

  17. Partitioning of plutonium from aqueous acidic wastes using a hollow fiber supported liquid membrane technique

    International Nuclear Information System (INIS)

    Transport of Pu(IV) from 3M HNO3 solutions across Aliquat-336/ Solvesso-100 by hollow fiber supported liquid membrane (HFSLM) was studied. Permeability of Pu(IV) through a bundle of hollow fibers made-up with 20 lumens, of 67 cm2 surface area, 9 cm length and operated at a flow rate of 10-8 m3/s on recycle mode was examined. More than 80% Pu from oxalate bearing wastes generated during reconversion process could be transported through 10% Aliquat-336/Solvesso-100 into hydroxylamine hydrochloride strippant in about three runs. (author)

  18. Influence of Ionic Liquid Content on Transport Properties of Dense Polymeric Membranes.

    Czech Academy of Sciences Publication Activity Database

    Izák, Pavel; Kačírková, Marie; Bernardo, P.; Jansen, J.C.

    Poznań : Poznan Science and Technology Park, 2016, s. 38. ISBN N. [COST CM1206 Meeting: WG1 and WG4 Workshop and MC Meeting: Advances on Green Technologies. Poznań (PL), 19.04.2016-20.04.2016] Institutional support: RVO:67985858 Keywords : polymeric membranes * ionic liquid * dsc analysis Subject RIV: CI - Industrial Chemistry, Chemical Engineering https://drive. google .com/file/d/0ByvzfYWTeIHMVkcyZ1J4VndTQU0/view?pref=2&pli=1

  19. Solvent extraction and liquid membrane transport studies of actinides using novel extractants

    International Nuclear Information System (INIS)

    For the safe management of radioactive wastes, 'Partitioning and Transmutation' (P and T) is being proposed as a strategy for the mitigation of long term hazards due to minor actinides (MA) and long lived fission products. This requires selective recovery of minor actinides from acidic feeds and thus necessitates development of extractants for their preferential extraction from high level waste. Several 'green' extractants such as functionalized malonamides and diglycolamides (DGA) have shown highly encouraging results. Out of the malonamides, DMDBTDMA and DMDOHEMA have been extensively tested for their actinide partitioning behaviour. Several diglycolamide extractants such as TPDGA, THDGA, TODGA, T2EHDGA and TDDGA have also been evaluated for their extraction properties. Interesting extraction properties of TODGA has led to thorough investigation of this reagent for the development of 'actinide partitioning' flow sheets at various laboratories. Liquid membrane separation of actinides from synthetic high level waste (SHLW) solution has also been carried out and shown highly promising results at significantly lower VOC inventories. About 20 L SHLW has been processed using hollow fiber supported liquid membrane technique. Novel DGA functionalized tripodal and calix(4)arene ligands were also evaluated for the extraction of actinides and fission products. The extraction mechanism was found to be entirely different with the calix(4)arene based DGA ligands as compared to those observed with extractants such as TODGA. Room temperature ionic liquids containing diglycolamide extractants have shown exceptionally high distribution coefficients and the results indicate possibility of selective recovery of Am from acidic waste solutions. Task specific ionic liquids containing DGA functional group have also been evaluated for actinide extraction under varying experimental conditions. (author)

  20. Direct determination of chlorophenols present in liquid samples by using a supported liquid membrane coupled in-line with capillary electrophoresis equipment.

    Science.gov (United States)

    Almeda, S; Nozal, L; Arce, L; Valcárcel, M

    2007-03-21

    Actually there is a great trend on the development of effective analytical methods for monitoring trace levels of various phenols which can indicate, among others compounds, the water quality. A simple, inexpensive supported liquid membrane (SLM) device was used in combination with commercially available capillary electrophoresis (CE) equipment for the direct determination of chlorophenols in surface water samples. The manifold was used simultaneously to extract and preconcentrate the analytes from liquid samples. In the extraction set-up, the donor phase (4 mL) was placed in the CE vial, where a micro-membrane extraction unit (MMEU) accommodating the acceptor phase (100 microL) in its lumen was immersed. The supported liquid membrane was constructed by impregnating a porous Fluoropore Teflon (PTFE) membrane with a water-immiscible organic solvent (dihexyl ether). The extraction process was optimized with regard to the pH of the donor and acceptor phases, membrane liquid, extraction time and voltage applied to the inlet or outlet vial during extraction. The chlorinated phenols pentachlorophenol (PCP), 2,3,6 trichlorophenol (TCP) and 2,6 dichlorophenol (DCP) were thus efficiently separated by CE, using tris(hydroxymethyl)aminomethane (Tris) and an NaH(2)PO(4) solution containing 1% (v/v) methanol at pH 10.5 as running buffer. PMID:17386759

  1. 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.

  2. Study of dynamic properties for NaK binary liquid alloy using first principle and theoretical predictions of isothermal bulk modulus using elastic constants

    International Nuclear Information System (INIS)

    Study of atomic motions in the binary liquid alloys have been studied in terms of dynamical variables like velocity auto correlation, power spectrum and mean square displacement. Elastic constants and isothermal bulk modulus have been calculated to see the effeectiveness of ab-initio pseudopotentials which has been used in this paper. This appraoch is free from the fitting parameters and results obtained using this appraoch have been found very close to the average values

  3. Study of dynamic properties for NaK binary liquid alloy using first principle and theoretical predictions of isothermal bulk modulus using elastic constants

    Energy Technology Data Exchange (ETDEWEB)

    Thakur, Anil, E-mail: anil-t2001@yahoo.com; Kashyap, Rajinder [Department of Physics, Govt. P. G. College Solan-173212, Himachal Pradesh (India); Sharma, Nalini; Ahluwalia, P. K. [Department of Physics, Himachal Pradesh University Shimla-171005, Himachal Pradesh (India)

    2014-04-24

    Study of atomic motions in the binary liquid alloys have been studied in terms of dynamical variables like velocity auto correlation, power spectrum and mean square displacement. Elastic constants and isothermal bulk modulus have been calculated to see the effeectiveness of ab-initio pseudopotentials which has been used in this paper. This appraoch is free from the fitting parameters and results obtained using this appraoch have been found very close to the average values.

  4. The Extraction of Uranium as Uranyl Nitrate Complex in The Nitrate Acid Solution by Liquid Membrane Emulsion Technique

    International Nuclear Information System (INIS)

    The extraction of uranium as uranyl nitrate complex in the nitrate acid solution has been carried out using a liquid membrane emulsion technique. The liquid membrane phase is in form of emulsion that consists of kerosene as the solvent, sorbitan monooleat (span-80) as the surfactant, di-2 ethyl phosphoric acids (D2EHPA) as the carrier agent, and phosphoric acids as the internal phase. The optimum conditions for the extraction of uranium as uranyl nitrate complex have been obtained as the following: the organic phase (O) and the water or internal liquid phase (W) ratio in the liquid membrane phase (O/W) was 1, the concentration of nitric acid in the external phase was 3M, the D2EHPH concentration was 10% (v/v), the extraction time was 5 minutes and the agitation speed to achieve a membrane emulsion was 7500 rpm. At this condition the extraction efficiency obtained was 94.24%. The experiments also showed that the amount of extracted uranium by the liquid. membrane emulsion was limited

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

    OpenAIRE

    Kazuo Kondo; Michiaki Matsumoto; Yuuki Murakami; Abhishek Panigrahi

    2011-01-01

    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,...

  6. Studies on the transport of actinides and lanthanides through DHDECMPO based supported liquid membranes (SLM)

    Energy Technology Data Exchange (ETDEWEB)

    Dudwadkar, N.L.; Tripathi, S.C.; Gandhi, P.M. [Bhabha Atomic Research Centre, Trombay, Mumbai (India). Fuel Reprocessing Div.

    2013-07-01

    This paper describes our studies on the partitioning of actinides from high level liquid waste of PUREX origin employing a supported liquid membrane technique. The process uses a solution of DHDECMPO in n-dodecane as a carrier with poly tetra fluoro ethylene support and a mixture of citric acid, formic acid and hydrazine hydrate as a receiving phase. Transport studies are carried out for {sup 241}Am under different experimental conditions to optimize the transport parameters such as feed acidity, carrier concentration and effect of uranium, Nd(III) and salt concentration in the feed. Studies indicated good transport of neptunium, americium and plutonium across the membrane from a nitric acid medium. Under the optimized conditions the transport of {sup 241}Am has been studied for uranium depleted synthetic PHWR-HLW and finally the technique is used for the partitioning of alpha emitters from an actual HLW after reprocessing. A high concentration of uranium in the feed is found to retard the transport of americium, suggesting the need of prior removal of uranium from the waste. Separation of actinides from uranium-lean simulated as well as actual HLW has been found to be feasible using the above described technique. (orig.)

  7. 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.

  8. 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

    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 configuration. Complete conversi...

  9. The evaluation of the mechanisms involved in the extraction of nickel from low concentration effluents by means of supported liquid membrane / Leon Rikus Koekemoer

    OpenAIRE

    Koekemoer, Leon Rikus

    2004-01-01

    From an economic point of view, the use of membranes at the present time is intermediate between the development of first generation membrane processes and second generation processes such as supported liquid membranes. The objective of this research was to investigate the mechanisms involved in the extraction of nickel from low concentration effluents by means of supported liquid membranes (SLM). A custom-made reactor/extractor was used for experimentation, based upon a proces...

  10. A liquid crystal polymer membrane MEMS sensor for flow rate and flow direction sensing applications

    International Nuclear Information System (INIS)

    The paper reports the design, fabrication and experimental results of a liquid crystal polymer (LCP) membrane-based pressure sensor for flow rate and flow direction sensing applications. Elaborate experimental testing results demonstrating the sensors' performance as an airflow sensor have been illustrated and validated with theory. MEMS sensors using LCP as a membrane structural material show higher sensitivity and reliability over silicon counterparts. The developed device is highly robust for harsh environment applications such as atmospheric wind flow monitoring and underwater flow sensing. A simple, low-cost and repeatable fabrication scheme has been developed employing low temperatures. The main features of the sensor developed in this work are a LCP membrane with integrated thin film gold piezoresistors deposited on it. The sensor developed demonstrates a good sensitivity of 3.695 mV (ms−1)−1, large operating range (0.1 to >10 ms−1) and good accuracy in measuring airflow with an average error of only 3.6% full-scale in comparison with theory. Various feasible applications of the developed sensor have been demonstrated with experimental results. The sensor was tested for two other applications—in clinical diagnosis for breath rate, breath velocity monitoring, and in underwater applications for object detection by sensing near-field spatial flow pressure

  11. 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%.

  12. Ionic Conductivity and Gas Permeability of Polymerized Ionic Liquid Block Copolymer Membranes

    Science.gov (United States)

    Evans, Christopher; Sanoja, Gabriel; Schneider, Yanika; Modestino, Miguel; Segalman, Rachel; Joint CenterArtificial Photosynthesis Team

    2014-03-01

    Polymer membranes for many energy applications, such as solar-to-hydrogen fuel production, require ionic conductivity while acting as gas diffusion barriers. We have synthesized a diblock copolymer consisting of poly(styrene-block-(4-(2-methacrylamidoethyl)-imidazolium trifluoroacetate) by treating poly(styrene-block-histamine methacrylamide) (PS- b-PHMA) with trifluoroacetic acid. The PS block serves as the structural support while the imidazolium derivative is an ion conducting polymerized ionic liquid (PIL). Small angle X-ray scattering and transmission electron microscopy demonstrate that the block copolymer self-assembles into well-ordered nanostructures, with lamellae and hexagonally packed cylindrical morphologies. The ionic conductivities of the PS-b-PHMA materials were as high as 2 x 10-4 S/cm while an order of magnitude increase in conductivity was observed upon conversion to PS-b-PIL. The ionic conductivity of the PS-b-PIL increased by a factor of ~ 4 up to 1.2 x 10-3 S/cm as the PIL domain size increased from 20 to 40 nm. These insights allow for the rational design of high performance ion conducting membranes with even greater conductivities via precise morphological control. Additionally, the role of thermal annealing on the ionic conductivity and gas permeability of copolymer membranes was investigated.

  13. Separation of actinides and lanthanides from acidic nuclear wastes by supported liquid membranes

    International Nuclear Information System (INIS)

    Supported liquid membranes, SLM, consisting of a solution of 0.25 M octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) and 0.75 M tributylphosphate (TBP) in decalin absorbed on thin microporous polypropylene supports, have been studied for their ability to perform selective separations and concentrations of actinide and lanthanide ions from synthetic acidic nuclear wastes. The permeability coefficients of selected actinides (Am, Pu, U, Np) and of some of the other major components of the wastes have been measured using SLMs in flat-sheet and hollow-fiber configurations. The results have shown that with the thin (25 μm) flat-sheet SLMs, using Celgard 2500 as support, the membrane permeation process is mainly controlled by the rate of diffusion through the aqueous boundary layers. With the thicker (430 μm) hollow-fiber SLMs, using Accurel hollow-fibers as support, the membrane permeation process is controlled by the rate of diffusion through both the SLM and the aqueous boundary layers. Hollow-fibers SLMs exhibited lower permeability coefficients and longer life-times. The experiments have shown that the actinides can be very efficiently removed from the synthetic waste solutions to the point that the resulting solution could be considered a non-transuranic waste (less than 100 mCi/g of disposed form). The work has demonstrated that actinide removal from synthetic waste solutions is a feasible chemical process at the laboratory scale level

  14. Prominent Fe-based bulk amorphous steel alloy with large supercooled liquid region and superior corrosion resistance

    International Nuclear Information System (INIS)

    Graphical abstract: SEM images of the surface profile on the blade edge-tip for (a) commercial blade and (b) Fe-B9 BAS blade. SEM images of blade edge-tip for (c) as-received commercial blade, (d) commercial blade after cutting test of 25 cm length, (e) as-prepared Fe-B9 BAS blade, and (f) Fe-B9 BAS blade after cutting test of 25 cm length. -- Highlights: • An Fe-based BAS with high GFA and large supercooled region has been successfully produced. • Fe-B9 BAS exhibits higher corrosion resistance than 304 SS and 316 SS in Hank’s solution. • Fe-B9 BAS blade exhibits much higher sharpness than the commercial one. • Fe-B9 BAS blade presents much better durability than the commercial one on cutting test. -- Abstract: A prominent Fe-base bulk amorphous steel (BAS) alloy which presents high glass forming ability (GFA), good corrosion resistance, superior mechanical properties and relative lower cost. The Fe41Cr15Co7Mo14C21−xBxY2 (x = 5–10) BAS rods with a diameter of 2–6 mm, can be fabricated by the suction casting method. The highest GFA value can be obtained by adjusting the ratio of boron/carbon, reaching to the value of γ = 0.4 and γm = 0.69 for the alloy composition of Fe41Ce15Co7Mo14C12B9Y2. Meanwhile, this alloy also presents very large supercooled liquid region up to 81 K, favourable to be fabricated into micro-surgery tools by thermoplastic forming. In addition, the Fe-base BAS alloy exhibits extremely high hardness around 1200 Hv. The anodic polarization measurement of the Fe-based BAS exhibits a higher corrosion resistance than 304 SS and 316 SS in the Hank’s balanced salt solution. The sharpness test results reveal that the Fe-based BAS blade exhibits much higher sharpness because of its lower surface roughness and higher hardness. Moreover, the Fe-base BAS blade presents much better durability on cutting testing, it can remain relatively sharper edge-tip with a low blade sharpness index (BSI) value of 0.38 (in comparison with the BSI value

  15. Simulation of cesium nitrate extraction by a calixarene. Application to supported liquid membranes transport

    International Nuclear Information System (INIS)

    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.)

  16. Self-assembly of azobenzene bilayer membranes in binary ionic liquid-water nanostructured media.

    Science.gov (United States)

    Kang, Tejwant Singh; Ishiba, Keita; Morikawa, Masa-aki; Kimizuka, Nobuo

    2014-03-11

    Anionic azobenzene-containing amphiphile 1 (sodium 4-[4-(N-methyl-N-dodecylamino)phenylazo]benzenesulfonate) forms ordered bilayer membranes in binary ionic liquid (1-ethyl-3-methylimidazolium ethyl sulfate, [C2mim][C2OSO3])-water mixtures. The binary [C2mim][C2OSO3]-water mixture is macroscopically homogeneous at any mixing ratio; however, it possesses fluctuating nanodomains of [C2mim][C2OSO3] molecules as observed by dynamic light scattering (DLS). These nanodomains show reversible heat-induced mixing behavior with water. Although the amphiphile 1 is substantially insoluble in pure water, it is dispersible in the [C2mim][C2OSO3]-water mixtures. The concentration of [C2mim][C2OSO3] and temperature exert significant influences on the self-assembling characteristics of 1 in the binary media, as shown by DLS, transmission electron microscopy (TEM), UV-vis spectroscopy, and zeta-potential measurements. Bilayer membranes with rod- or dotlike nanostructures were formed at a lower content of [C2mim][C2OSO3] (2-30 v/v %), in which azobenzene chromophores adopt parallel molecular orientation regardless of temperature. In contrast, when the content of [C2mim][C2OSO3] is increased above 60 v/v %, azobenzene bilayers showed thermally reversible gel-to-liquid crystalline phase transition. The self-assembly of azobenzene amphiphiles is tunable depending on the volume fraction of [C2mim][C2OSO3] and temperature, which are associated with the solvation by nanoclusters in the binary [C2mim][C2OSO3]-water media. These observations clearly indicate that mixtures of water-soluble ionic liquids and water provide unique and valiant environments for ordered molecular self-assembly. PMID:24528277

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

    International Nuclear Information System (INIS)

    Highlights: • SiO2 spheres were modified by poly (ionic liquid) brushes via RATRP. • Positively charged NF membranes were fabricated by incorporation of SiO2-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

  18. 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.

  19. Gas Separation Using PES-MMT Membrane/Ionic Liquid/PES-MMT Membrane in a Sandwich Form

    Czech Academy of Sciences Publication Activity Database

    Liang, Ch.-Y.; Petričkovič, Roman; Uchytil, Petr; Suen, S.-Y.

    - : -, 2011, ICOM672. ISBN N. [International Congress on Membranes and Membrane Processes ICOM 2011. Amsterdam (NL), 23.07.2011-29.07.2011] Institutional research plan: CEZ:AV0Z40720504 Keywords : membrane * gas * separation Subject RIV: CI - Industrial Chemistry, Chemical Engineering http://icom2011.org/

  20. Intake of Uranium in waste water with Membrane Technique of Liquid Emulsion

    International Nuclear Information System (INIS)

    The separation of the waste of uranium solution has been investigated. The surfactant is Span-80 (Sorbital monooleate), the liquid membrane phase consist of the organic phase (o), the internal liquid phase (w) with ratio of o/w = 1, and the surfactant. The organic phase using TBP in kerosine was used as an organic phase and the internal liquid phase was sodium carbonate. The variables studied were the concentration of surfactant, the emulsification time, the speed of stirrer and the extractant concentration. The data of the research showed that, the optimum condition was as follows: The concentration of surfactant was 5%, emulsification time was 5 minutes, the emulsion speed was 7500 rpm and the concentration of surfactant was 5%. In this condition it was found that, the external phase of the distribution coefficient (Kd) phase external = 4.52, the internal phase was = 3.03 and efficiency of the external phase = 81.88%, efficiency of the internal phase 75.22%

  1. 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.

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

    OpenAIRE

    Moore, E.K.; Hopmans, E.C.; Rijpstra, W.I.C.; Villanueva, L; Sinninghe Damste, 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 become the primary method for analysis ofIPLs. Many glycerol-free amino acid containing membrane lipids (AA-IPLs), which are structurally different thanabundant aminophospholipids, have not been char...

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

    OpenAIRE

    Bor-Kuan Chen; Jhong-Ming Wong; Tzi-Yi Wu; Lung-Chuan Chen; I-Chao Shih

    2014-01-01

    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-phenoxy)phenyl]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 enhanc...

  4. Effects of hot liquid-water treatment on local proton conductivity at surfaces of sulfonated poly(arylene ketone) block copolymer membrane for fuel cells studied by current-sensing atomic force microscopy

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • Proton-conductive areas on SPK-bl-1 surfaces were investigated by current-sensing AFM. • The distributions of proton-conductive spots on the substrate and air sides were different. • After the hot-water treatment, the surface morphology changed, and the surface conductivity increased. • After the hot water treatment, the bulk structure, water uptake, and conductivity did not change. • The relationship between the MEA conditioning and the hot-water treatment was discussed. - Abstract: Microscopic proton conductivity at surfaces of a hydrocarbon-type polymer electrolyte membrane of sulfonated poly(arylene ketone) block copolymers (SPK-bl-1) was investigated by current-sensing atomic force microscopy (CS-AFM) under a hydrogen atmosphere. The distributions of proton-conductive regions on the SPK-bl-1 membrane surfaces were different on two surface sides of the membrane: the substrate side and the air side after being cast on a poly(ethylene terephthalate) substrate. After a liquid-water treatment of the membrane at 60 °C, the surface morphology of both sides changed. The proton-conductive area and the “pseudo current density” increased especially on the substrate side, and the difference between two sides of the membrane became very small. The scanning transmission electron microscopy inside the membrane showed no structural change after the hot-water treatment, and the water uptake and conductivity of the membrane were also unchanged. This hot liquid-water treatment activating the membrane surfaces should be related to the conditioning processes of the membrane-electrode assemblies of polymer electrolyte fuel cells

  5. Study of the extraction and the purification of americium and trivalent actinides contained in effluents with supported liquid membranes

    International Nuclear Information System (INIS)

    The supported liquid membrane technique is studied and developed for americium recovery from uranium or plutonium matrices and decontamination of liquid radioactive wastes. First tests on uranium-nickel solutions with a flat membrane showed the easiness of the operation and the efficiency of the process. Acid-resistant (10 N), interchangeable elements with hollow fibers, are developed and also a computerized automatic device. The different tests on americium solutions demonstrate the feasibility and the reliability of the system. Influence of various parameters on transfer kinetics is investigated

  6. 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...

  7. 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.

  8. 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.

  9. 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.

  10. Carrier facilitated transport of thorium from HCl medium using Cyanex 923 in n-dodecane containing supported liquid membrane

    International Nuclear Information System (INIS)

    Present studies deal with supported liquid membrane (SLM) technique for the separation of thorium from hydrochloric acid (HCl) medium using Cyanex 923 as a carrier. Effects of feed acidity, strippant, and membrane pore size and membrane thickness on the transport of thorium have been studied in detail. The optimized parameters were applied for separation of thorium from a radioanalytical waste. Stability of the membrane and membrane support was investigated. Transport of thorium increased from 78.3 to about 93.7 % with increase in acidity from 0.5 to 2 M using 0.3 M Cyanex 923 in n-dodecane as carrier and 2 M ammonium carbonate as stripping phase. The transport of thorium decreased above 2 M HCl. An attempt was made to model the physicochemical transport of thorium in SLM and understand the mechanism of thorium transport. (author)

  11. 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. PMID:27264787

  12. Cesium transport across flat sheet supported liquid membrane containing CCD in NPOE-dodecane mixture

    International Nuclear Information System (INIS)

    137Cs is an important fission product of concern for separation scientists working in the area of radioactive waste management. Removal of this long lived heat and gamma ray emitting radionuclides (t1/2 = 30.2 y) from radioactive waste would drastically bring down the MANREM problem. In addition to this, the recovered cesium can find applications in irradiators for sterilization of foods, medical accessories, sewage sludge treatment, etc. Chlorinated cobalt dicarbollide (CCD) in nitrobenzene and xylene mixture as the diluent has been used for the extraction of radio-cesium from acidic wastes. Other studies have used phenyl trifluoromethylsulfone (FS-13) as the diluent and have been used for supported liquid membrane (SLM) based separation methods which not only have the advantage of simultaneous extraction and stripping, but also drastically cut down the VOC inventory which is welcome from environmental concern point of view

  13. 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

    concentration 10 µg/mL was used. Extraction time was 5 min with an electric potential of 10 V and 900 rpm agitation of the sample vial. The samples were extracted through a hollow fiber-based SLM with different compositions of organic solvents and carriers. A small volume of acidified acceptor solution (25 µ......L) was after extraction analyzed directly, or with some dilution, on CE or HPLC. This article has identified mono- or di-substituted phosphate groups as the prominent group of carrier molecules needed to obtain acceptable recoveries. For the organic solvents, primary alcohols and ketones have shown......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...

  14. Evaluation of different extractants for actinide partitioning by hollow fiber supported liquid membrane

    International Nuclear Information System (INIS)

    The performance of different solvents for actinide partitioning, viz. TRUEX, DIAMEX and diglycolamide solvents was compared for the first time in hollow fibre supported liquid membrane (HFSLM) for the transport of trivalent actinides. In case of diglycolamide solvents, viz. 0.1M TODGA + 0.5M DHOA and 0.2M TEHDGA + 30% isodecanol, quantitative transport of Am (III) was achieved in 30 minutes from a solution containing 0.6g/L Nd at 3 M HNO3. In case of TRUEX solvent (0.2M CMPO + 1.2 M TBP), only 50% transport was achieved due to significant amount of acid transport. However, quantitative transport of Am (III) was possible after neutralization of the feed acidity. On the other hand, DIAMEX solvent (1M DMDBTDMA) gave about 85% transport under identical conditions. (author)

  15. Simulation Study on Separation of Cobalt and Nickel Using Multi-Hollow Fiber Supported Liquid Membrane

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jeong Woo; Oh, Byung Keun; Youn, In Ju; Lee, Won Hong [Department of Chemical Engineering, Sogang University, Seoul (Korea); Cho, Kyung Sang [IBM T. J. Waston Research Center, Yorktown (United States)

    2001-05-01

    Selective separation of cobalt ion from a feed solution, which contains cobalt and nickel ions, using a multi-stage hollow fiber supported liquid membrane (HFSLM) process with recirculation was analyzed to evaluate the design parameters. Mathematical models based on mass balance of a fully developed and a laminar flow in a cylindrical geometry were established. The model equations could be solved by using an orthogonal collocation technique. The effect of various operating conditions such as pH in the feed phase, carrier composition, nickel ion concentration, circulation flow rate and recirculation ratio was simulated. The optimum operating conditions for the highest flux and separation factor of cobalt ion were determined by the simulation results. 15 refs., 12 figs., 1 tab.

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

    International Nuclear Information System (INIS)

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

  17. A new emulsion liquid membrane based on a palm oil for the extraction of heavy metals.

    Science.gov (United States)

    Björkegren, Sanna; Karimi, Rose Fassihi; Martinelli, Anna; Jayakumar, Natesan Subramanian; Hashim, Mohd Ali

    2015-01-01

    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. PMID:25915191

  18. 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.

  19. Mixed reverse micelles facilitated downstream processing of lipase involving water-oil-water liquid emulsion membrane.

    Science.gov (United States)

    Bhowal, Saibal; Priyanka, B S; Rastogi, Navin K

    2014-01-01

    Our earlier work for the first time demonstrated that liquid emulsion membrane (LEM) containing reverse micelles could be successfully used for the downstream processing of lipase from Aspergillus niger. In the present work, we have attempted to increase the extraction and purification fold of lipase by using mixed reverse micelles (MRM) consisting of cationic and nonionic surfactants in LEM. It was basically prepared by addition of the internal aqueous phase solution to the organic phase followed by the redispersion of the emulsion in the feed phase containing enzyme, which resulted in globules of water-oil-water (WOW) emulsion for the extraction of lipase. The optimum conditions for maximum lipase recovery (100%) and purification fold (17.0-fold) were CTAB concentration 0.075 M, Tween 80 concentration 0.012 M, at stirring speed of 500 rpm, contact time 15 min, internal aqueous phase pH 7, feed pH 9, KCl concentration 1 M, NaCl concentration 0.1 M, and ratio of membrane emulsion to feed volume 1:1. Incorporation of the nonionic surfactant (e.g., Tween 80) resulted in remarkable improvement in the purification fold (3.1-17.0) of the lipase. LEM containing a mixture of nonionic and cationic surfactants can be successfully used for the enhancement in the activity recovery and purification fold during downstream processing of enzymes/proteins. PMID:24930827

  20. 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.

  1. Application of supported liquid membranes for removal of uranium from groundwater

    International Nuclear Information System (INIS)

    The separation of uranium from Hanford site groundwater as studied by hollow-fiber supported liquid membranes, SLM. The carrier bis(2,4,4-trimethylpentyl)phosphinic acid, H[DTMPep], contained in the commercial extractant Cyanex trademark 272 was used as a membrane carrier, because of its selectivity for U over calcium and magnesium. The water soluble complexing agent, 1-hydroxyethane-1,1-diphosphonic acid, HEDPA, was used as stripping agent. Polypropylene hollow-fibers and n-dodecane were used as polymeric support and diluent, respectively. Laboratory scale hollow-fiber modules were employed in a recycling mode, using as feed synthetic groundwater at pH 2, to confirm the capability of the proposed SLM system to separate and concentrate U(VI) in the strip solution. Information was obtained on the U(VI) concentration factor and on the long-term performance of the SLMs. Encouraging results were obtained both with a conventional module and with a module containing a carrier solution reservoir. Industrial scale modules were used at Hanford to test the SLM separation of U(VI) from real contaminated groundwater. The uranium concentration was reduced from approximately 3500 ppB to about 1 ppB in a few hours. 9 refs., 8 figs., 4 tabs

  2. 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.

  3. Application of supported liquid membranes for removal of uranium from groundwater

    International Nuclear Information System (INIS)

    The separation of uranium from Hanford site groundwater was studied by hollow-fiber supported liquid membranes, SLM. The carrier bis(2,4,4-trimethylpentyl)phosphinic acid, H(DTMPeP), contained in the commercial extractant Cyanex trademark 272 was used as membrane carrier, because of its selectivity for U over calcium and magnesium. The water soluble complexing agent, 1-hydroxyethane-1,1-diphosphonic acid, HEDPA, was used as stripping agent. Polypropylene hollow-fibers and n-dodecane were used as polymeric support and diluent, respectively. Laboratory scale hollow-fiber modules were employed in a recycling mode, using as feed synthetic groundwater at pH 2, to confirm the capability of the proposed SLM system to separate and concentrate U(VI) in the strip solution. Information was obtained on the U(VI) concentration factor and on the long-term performance of the SLMs. Encouraging results were obtained both with a conventional module and with a module containing a carrier solution reservoir. Industrial scale modules were used at Hanford to test the SLM separation of U(VI) from real contaminated groundwater. The uranium concentration was reduced from approximately 3,500 ppb to about 1 ppb in a few hours. 9 refs., 8 figs., 4 tabs

  4. Application of functionalized calixarenes to the processing of radioactive effluents by supported liquid membranes

    International Nuclear Information System (INIS)

    In a first part, this research thesis presents the general context of nuclear waste processing (nature of wastes to be processed, characteristics of the used method and products), and proposes an overview of results obtained during previous campaigns which were based on the use of the technique of supported liquid membranes, but with other types of extracting components. The second part focuses on the tracking of complexing and extractive properties of all functionalized calixarenes which had been synthesised by different research teams. Several experiments have been performed to determine the extraction efficiency and selectivity of these organic compounds with respect to the studied radio-elements. The third part reports the detailed study of a specific family of functionalized calixarenes for which two thermodynamic models of membrane transport described in the literature have been applied. Validity limits are discussed with respect to operation conditions. Some results are finally given on the caesium and actinide (neptunium, plutonium) decontamination of synthetic concentrates which simulate actual radioactive wastes

  5. Extraction of anionic dye from aqueous solutions by emulsion liquid membrane.

    Science.gov (United States)

    Dâas, Attef; Hamdaoui, Oualid

    2010-06-15

    In this work, the extraction of Congo red (CR), an anionic disazo direct dye, from aqueous solutions by emulsion liquid membrane (ELM) was investigated. The important operational parameters governing emulsion stability and extraction behavior of dye were studied. The extraction of CR was influenced by a number of variables such as surfactant concentration, stirring speed, acid concentration in the feed solution and volume ratios of internal phase to organic phase and of emulsion to feed solution. Under most favorable conditions, practically all the CR molecules present in the feed phase were extracted even in the presence of salt (NaCl). At the optimum experimental conditions, total removal of antharaquinonic dye Acid Blue 25 was attained after only 10 min. Influence of sodium carbonate concentration as internal receiving phase on the stripping efficiency of CR was examined. The best sodium carbonate concentration in the internal phase that conducted to excellent stripping efficiency (>99%) and emulsion stability was 0.1N. The membrane recovery was total and the permeation of CR was not decreased up to seven runs. ELM process is a promising alternative to conventional methods and should increase awareness of the potential for recovery of anionic dyes. PMID:20211520

  6. Supported liquid membrane-protected molecularly imprinted fibre for solid-phase microextraction of thiabendazole.

    Science.gov (United States)

    Barahona, Francisco; Turiel, Esther; Martín-Esteban, Antonio

    2011-05-23

    In this work, molecularly imprinted polymer fibres (MIP-fibre) have been prepared and evaluated for solid-phase microextraction (SPME), using thiabendazole (TBZ) as template. Inherent limitations of molecular imprinted polymers, such as target recognition in aqueous media, have been solved with the use of organic supported liquid membrane (SLM) protecting the MI-SPME process. MIP-fibres were located inside a polypropylene hollow capillary and protected by an organic solvent immobilized as a thin SLM in the pores of the capillary wall. The extraction procedure involved two simultaneous processes: liquid phase microextraction using polypropylene hollow fibres (HF-LPME) of the analytes from the sample to an organic acceptor solution through a SLM; and SPME of the analytes from the organic acceptor solution to a MIP-fibre inside the polypropylene capillary. The developed methodology was optimized and applied to the extraction of TBZ form spiked orange juices. Calibration curves showed good linearity in the concentration range under study (0.01-5.00 mg L(-1)) and a regression coefficient better than 0.995 was obtained. The detection limit was 4 μg L(-1), low enough to permit the satisfactory analysis of TBZ in real samples, according to European regulation. Relative standard deviations ranged below 10%, indicating good repeatability. By this manner, the advantages of inherent selectivity of MIP SPME fibres and the enrichment and sample cleanup capability of the HF-LPME have been successfully combined into a single device. PMID:21565306

  7. 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 Damste, 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

  8. Effect of the Phase Volume Ratio on the Potential of a Liquid-Membrane Ion-Selective Electrode

    Czech Academy of Sciences Publication Activity Database

    Samec, Zdeněk; Girault, H. H.

    2004-01-01

    Roč. 76, č. 14 (2004), s. 4150-4155. ISSN 0003-2700 R&D Projects: GA MŠk ME 502 Institutional research plan: CEZ:AV0Z4040901 Keywords : liquit-membrane * ion-selective electrode * two.phase liquid system Subject RIV: CG - Electrochemistry Impact factor: 5.450, year: 2004

  9. 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. PMID:24490850

  10. Separation of trivalent actinides and lanthanides using a flat sheet supported liquid membrane containing Cyanex-301 as the carrier

    International Nuclear Information System (INIS)

    In the present work the transport rates and poor decontamination factors. In the present work the transport behaviour of several trivalent lanthanides viz. La3+, Eu3+, Tb3+, Ho3+, Yb3+, Lu3+ and actinides viz. Am3+, Cm3+ was investigated using Cyanex-301 in n-dodecane as the carrier and polypropylene as the solid support for the liquid membrane

  11. Dynamic Membrane Formation in Anaerobic Dynamic Membrane Bioreactors: Role of Extracellular Polymeric Substances

    OpenAIRE

    Yu, Hongguang; Wang, Zhiwei; Wu, Zhichao; Zhu, Chaowei

    2015-01-01

    Dynamic membrane (DM) formation in dynamic membrane bioreactors plays an important role in achieving efficient solid-liquid separation. In order to study the contribution of extracellular polymeric substances (EPS) to DM formation in anaerobic dynamic membrane bioreactor (AnDMBR) processes, EPS extraction from and re-addition to bulk sludge were carried out in short-term filtration tests. DM formation behaviors could be well simulated by cake filtration model, and sludge with EPS re-addition ...

  12. 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.

  13. Deformation of Zr41 Ti14 CU12.5 Ni10 Be22.5 bulk amorphous alloy under isobaric pressure in super-cooled liquid region

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ke-qin; LU Qi-zhu

    2005-01-01

    The curve of crystallization transition during continuous heating for the Zr41Ti14Cu12.5Ni10Be22.5 bulk amorphous alloy was measured by means of dilatation(Fully automatic transformation recording/measuring instrument) and X-ray diffraction(XRD) method. The deformation behavior of the alloy at various heating rates in the supercooled liquid region was studied. The results show that the glass transition temperature of the alloy increases slightly and the supercooled liquid region(SLR) increases significantly with increasing heating rate. The deformation amount under isobaric pressure of 1 N for the alloy in the SLR increases with increasing heating rate. As the heating rate of the alloy increases from 5 to 100 ℃/min, the amount of deformation of the alloy increases from 8.3% to 45%.

  14. Membrane filtration of the liquid fraction from a solid-liquid separator for swine manure using a cationic polymer as flocculating agent.

    Science.gov (United States)

    Masse, L; Mondor, M; Dubreuil, J

    2013-01-01

    The liquid fraction from a solid-liquid separator for swine manure, which used a cationic polymer to promote particle flocculation, was processed by one nanofiltration and two reverse osmosis spiral-wound membranes. Eight different liquid fraction batches (750 to 1750 L) were concentrated at volumetric concentration ratios (VCRs, initial to final volumes) ranging from 2.3 to 4.2. Membrane fouling intensity was highly variable, as water flux recovery after concentration cycles ranged from 13% to 88%. The most severe fouling was caused by a liquid fraction that had relatively low suspended solids (SS) (774 mg/L) and was concentrated at a low VCR of 2.6. Raw manure collected the same day also contained low SS, suggesting that fewer sites were available for polymer adsorption and thus more polymer remained in the liquid. However, because of the high opacity of the samples, residual polymer could not be detected in any feed or concentrate samples. Fouling was not totally irreversible as over 97% of membrane flux could be recovered by cleaning with acidic and alkaline solutions. Further tests with spiked liquid fractions indicated that fouling due to residual polymer in solution started to occur at a polymer concentration of 3 and 11 mg/L in initial and concentrated effluents, respectively. If a cationic polymer is used to pretreat manure, the amount of added polymer would have to be closely related to SS content as opposed to manure volume, in order to leave very little residual polymer in solution. PMID:23837317

  15. Performance analysis of small capacity liquid nitrogen generator based on Joule-Thomson refrigerator coupled with air separation membrane

    Science.gov (United States)

    Piotrowska-Hajnus, Agnieszka; Chorowski, Maciej

    2012-06-01

    Joule - Thomson small capacity refrigerators supplied with gas mixture are studied theoretically and experimentally for a variety of applications. They can be especially promising when coupled with membrane air separators. We present liquid nitrogen generation system based on Joule - Thomson cooler joined with air separation membrane. Hollow fiber membrane is used for nitrogen separation from compressed and purified atmospheric air. Joule-Thomson refrigerator operates with a dedicated nitrogen - hydrocarbons mixture and provides a cooling power used for the separated nitrogen liquefaction. Special attention has been paid to a heat exchanger coupling the Joule- Thomson refrigerator with the membrane air separator. This paper describes the system design, the procedure of its working parameters optimization and tests results.

  16. Isolation and preconcentration of Cd(II) from environmental samples using polypropylene porous membrane in a hollow fiber renewal liquid membrane extraction procedure and determination by FAAS

    International Nuclear Information System (INIS)

    The use of polypropylene porous membrane in a hollow fiber renewal liquid membrane (HFRLM) procedure for determination of Cd(II) in water samples was assessed. Ammonium O,O-diethyl dithiophosphate (DDTP) was used to complex cadmium (II) in an acid medium to obtain a neutral hydrophobic complex. The organic solvent introduced to the sample extracts this complex from the aqueous solution and carries it over the polypropylene membrane porous. The organic solvent is immobilized inside the polypropylene membrane porous, leading to an homogeneous phase. The complex strips the lumen of the membrane where, at higher pH, the complex Cd-DDTP is broken down and Cd(II) is released into the stripping phase. EDTA was used to complex the cadmium (II), helping to trap the analyte in the stripping phase. The optimized variables were: sample pH, DDTP concentration, stripping pH, EDTA concentration, extraction temperature and time, extractor solvent and addition of salt to saturate the sample. The sample volume used was 15 mL and the stripping volume was 165 μL. The analyte enrichment factor was 107, limit of detection 1.5 μg L-1, relative standard deviation 4.0% (15 μg L-1, n = 7) and the working linear range 5-30 μg L-1.

  17. 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.

  18. Long-duration nano-second single pulse lasers for observation of spectra from bulk liquids at high hydrostatic pressures

    International Nuclear Information System (INIS)

    The influence of laser pulse duration on the spectral emissions observed from bulk ionic solutions has been investigated for hydrostatic pressures between 0.1 and 30 MPa. Transient pressure, shadowgraph imaging and spectroscopic measurements were performed for single pulses of duration 20 and 150 ns. The transient pressure measurements show that for hydrostatic pressures up to 30 MPa, propagation of the high-pressure shockwave generated by the focused laser causes the local pressure to reduce below ambient levels during the time frame that spectroscopic measurements can be made. The pressure impulse and subsequent reduction in pressure are larger, with the latter lasting longer for the 150 ns pulse compared to a 20 ns pulse of the same energy. The 150 ns pulse generates larger cavities with significant enhancement of the spectral emissions observed compared to the 20 ns duration pulse for pressures up to 30 MPa. The results demonstrate that laser-induced breakdown using a long ns duration pulse offers an advantage over conventional, short ns duration pulses for the analysis of bulk ionic solutions at hydrostatic pressures between 0.1 and 30 MPa. - Highlights: • Long-ns-duration laser pulses enhance the spectra observed from bulk solutions. • Laser-induced shockwaves momentarily reduce pressures to below ambient levels. • 150 ns pulses generate larger cavities than 20 ns pulses of the same energy. • Hydrostatic pressures < 30 MPa have no significant effect on the observed spectra

  19. Optical chirality of protonated tetraphenylporphyrin J-aggregate formed at the liquid-liquid interface in a centrifugal liquid membrane cell

    International Nuclear Information System (INIS)

    J-aggregation of an achiral hydrophobic porphyrin, 5,10,15,20-tetraphenylporphyrin (H2TPP), at a toluene-4 M sulfuric acid interface was studied by a centrifugal liquid membrane-circular dichroism (CLM-CD) method. It was found for the first time that the exciton chirality sign of the interfacial J-aggregate of H4TPP2+ was affected by the rotational direction of the cylindrical CLM cell: a negative sign for clockwise (CW) rotation and a positive sign for anticlockwise (ACW) rotation. The sign of the measured optical chirality also depended on the injection position of the H2TPP stock solution in the rotating cell. Furthermore, it was observed that the rotational linear velocity of the aqueous phase was faster than that of the toluene phase, when the CLM cell was rotated at 7000 rpm. The effects of rotational direction and sample injection position on the optical chirality were overcome by the effect of chiral counter-ions such as (+)- or (-)-camphorsulfonic anions. From the observed results, a possible mechanism for the generation of the optical chirality of the interfacial J-aggregate was proposed taking into account an interfacial shear force and the spreading direction of H2TPP in the toluene phase

  20. Operation of a breadboard liquid-sorbent/membrane-contactor system for removing carbon dioxide and water vapor from air

    Science.gov (United States)

    Mccray, Scott B.; Ray, Rod; Newbold, David D.; Millard, Douglas L.; Friesen, Dwayne T.; Foerg, Sandra

    1992-01-01

    Processes to remove and recover carbon dioxide (CO2) and water vapor from air are essential for successful long-duration space missions. This paper presents results of a developmental program focused on the use of a liquid-sorbent/membrane-contactor (LSMC) system for removal of CO2 and water vapor from air. In this system, air from the spacecraft cabin atmosphere is circulated through one side of a hollow-fiber membrane contactor. On the other side of the membrane contactor is flowed a liquid sorbent, which absorbs the CO2 and water vapor from the feed air. The liquid sorbent is then heated to desorb the CO2 and water vapor. The CO2 is subsequently removed from the system as a concentrated gas stream, whereas the water vapor is condensed, producing a water stream. A breadboard system based on this technology was designed and constructed. Tests showed that the LSMC breadboard system can produce a CO2 stream and a liquid-water stream. Details are presented on the operation of the system, as well as the effects on performance of variations in feed conditions.

  1. 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)

  2. A heat pump driven and hollow fiber membrane-based liquid desiccant air dehumidification system: Modeling and experimental validation

    International Nuclear Information System (INIS)

    A compression heat pump driven and membrane-based liquid desiccant air dehumidification system is presented. The dehumidifier and the regenerator are made of two hollow fiber membrane bundles packed in two shells. Water vapor can permeate through these membranes effectively, while the liquid desiccant droplets are prevented from cross-over. Simultaneous heating and cooling of the salt solution are realized with a heat pump system to improve energy efficiency. In this research, the system is built up and a complete modeling is performed for the system. Heat and mass transfer processes in the membrane modules, as well as in the evaporator, the condenser, and other key components are modeled in detail. The whole model is validated by experiment. The performances of SDP (specific dehumidification power), dehumidification efficiency, EER (energy efficiency ratio) of heat pump, and the COP (coefficient of performance) of the system are investigated numerically and experimentally. The results show that the model can predict the system accurately. The dehumidification capabilities and the energy efficiencies of the system are high. Further, it performs well even under the harsh hot and humid South China weather conditions. - Highlights: • A membrane-based and heat pump driven air dehumidification system is proposed. • A real experimental set up is built and used to validate the model for the whole system. • Performance under design and varying operation conditions is investigated. • The system performs well even under harsh hot and humid conditions

  3. Penetration of gas discharge through the gas–liquid interface into the bulk volume of conductive aqueous solution

    Czech Academy of Sciences Publication Activity Database

    Hoffer, Petr; Koláček, Karel; Stelmashuk, Vitaliy; Lukeš, Petr

    2015-01-01

    Roč. 43, č. 11 (2015), s. 3868-3875. ISSN 0093-3813 R&D Projects: GA ČR(CZ) GA15-12987S Institutional support: RVO:61389021 Keywords : atmospheric-pressure plasmas * electric discharges * liquids * water Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.101, year: 2014

  4. Supported liquid membrane extraction of 99mTc(VII) in a hollow fibre contactor

    International Nuclear Information System (INIS)

    Supported liquid membrane (SLM) extraction of 99mTc(VII) in a hollow fiber contactor was investigated in this study. Technetium in a form of pertechnetate was extracted in the three phase system, from the acidic donor solution through the organic phase placed in the membrane pores and then to the alkaline acceptor solution. Tri-n-octylamine as a well known selective extractant for the separation of technetium from molybdenum was applied for this purpose. The aim of this work was to characterize SLM extraction of 99mTc in order to investigate the applicability of this technique for the alternative, cyclotron production of 99mTc and other positron emitting isotopes of Tc. SLM extraction of 99mTc (VII) was performed in a membrane contactor consisting of a glass housing in a form of U-shaped glass tube and a single hollow fiber. The microporous hydrophobic polypropylene hollow fiber membrane (Hoechst-Celanese, USA) was used in this study. The inner diameter of the hollow fiber was 280 μm, the thickness of the wall was 190 μm, and the length of the hollow fiber was 120 mm. The donor solution was initially containing 13 kBq 99mTc (VII) in 1 dm3 0.9 % NaCl at pH=3-4 and fed along the lumen of the hollow fiber, either in continuous or recirculated mode of operation, by a peristaltic pump. The membrane was impregnated by soaking in the organic phase (50% tri-n-octylamine in hexane) for 1h, which was followed by washing in a water-bath in order to remove the excess of the solvent. The acceptor solution containing 0.1 mol·dm-3 NaOH was fed along the shell side in continuous mode of operation. The activity concentration of 99mTc in the donor and acceptor solution was determined using an automated γ-counter. The transport of 99mTc(VII) across the tri-n-octylamine-hexane based SLM as a function of the donor flow rate under continuous and recirculation mode of operation was investigated. The obtained results are discussed in terms of extraction efficiency, mass transfer

  5. Effects of configurational changes on electrical resistivity during glass-liquid transition of two bulk metal-alloy glasses

    International Nuclear Information System (INIS)

    Consequences of increase in structural fluctuations on heating Pd40Ni10Cu30P20 and Zr46.75Ti8.25Cu7.5Ni10Be27.5 through their glass to liquid transition range were investigated by measuring the electrical resistivity, ρ, an electron scattering property. The temperature coefficient of resistivity (TCR = (1/ρ) dρ/dT) of the liquid and glassy states is negative. The plots of their ρ against T in the Tg (glass to liquid transition) range show a gradual change in the slope similar to the change observed generally for the plots of the density, elastic modulus, and refractive index. As fluctuations in the melt structure involve fewer configurations on cooling, ρ increases. In the energy landscape description, the melt's structure explores fewer minima with decrease in T, vibrational frequencies increase, and electron scattering and ρ increase. Plots of (−dρ/dT) against T resemble the plot of the specific heat of other glasses and show a sub-Tg feature and a rapid rise at T near Tg. Analysis shows that the magnitude of negative TCR is dominated by change in the phonon characteristics, and configurational fluctuations make it more negative. The TCR of the liquid and glassy states seems qualitatively consistent with the variation in the structure factor in Ziman's model for pure liquid metals as extended by Nagel to metal alloys and used to explain the negative TCR of a two-component metal glass

  6. The Liquid Sensor Using Thin Film Bulk Acoustic Resonator with C-Axis Tilted AlN Films

    OpenAIRE

    Ying-Chung Chen; Wei-Tsai Chang; Kuo-Sheng Kao; Chun-Hung Yang; Chien-Chuan Cheng

    2013-01-01

    Dual-mode thin film bulk acoustic resonator (TFBAR) devices are fabricated with c-axis tilted AlN films. To fabricate dual-mode TFBAR devices, the off-axis RF magnetron sputtering method for the growth of tilted piezoelectric AlN thin films is adopted. In this report, the AlN thin films are deposited with tilting angles of 15° and 23°. The frequency response of the TFBAR device with 23° tilted AlN thin film is measured to reveal its ability to provide dual-mode resonance. The sensitivities of...

  7. Ionic liquid-based hollow fiber supported liquid membrane extraction combined with thermospray flame furnace AAS for the determination of cadmium

    International Nuclear Information System (INIS)

    We have developed a simple and effective method for hollow fiber liquid-phase microextraction of cadmium. It is based on the use of a room temperature ionic liquid (RTIL) and was coupled to thermospray flame furnace AAS. The RTIL was placed in the pores of a polypropylene hollow fiber (acting as a liquid membrane) and also used as the acceptor solution. Ammonium pyrrolidine dithiocarbamate (APDC) was used as the chelating agent. The effects of the concentration of APDC, the pH of samples, stirring rates, extraction time, and potential interferences were optimized to result in a detection limit of 9 ng L-1 and an enrichment factor of 90. The relative standard deviation is 4. 7% (at 0. 5 ng mL-1, for n = 5). The method was successfully applied to the determination of cadmium. (author)

  8. Hollow fibre supported liquid membrane: a novel approach for nuclear waste remediation

    International Nuclear Information System (INIS)

    Hollow Fibre Supported Liquid Membranes (HFSLM) are the focus of separation studies in various fields including metal ion separations. This technique offers the advantages of active transport, possible usage of exotic carriers, easy scale-up, low energy requirements, low capital and operating costs, etc. For past few years, Radiochemistry Division has been actively involved in the development of HFSLM separation processes for actinide partitioning, lanthanide/actinide separation, Sr/Y separation as well as recovery of radio-cesium from nuclear waste. The actinide partitioning studies have been successfully demonstrated at 20 L scale using PHWR Simulated High Level Waste (SHLW) using diglycolamide extractants. The studies were extended for lanthanide/actinide separation studies at 1 L scale using Cyanex 301 as the extractant. The HFSLM technique was also applied for the recovery of Cs and the separation of 90Y from 90Sr using calix-bis-crown-6 and PC 88A, respectively as the carrier extractant. The physical, chemical and radiolytic stability of the HFSLM system has been investigated. This lecture will give an overview of the HFSLM work carried out at Radiochemistry Division, Bhabha Atomic Research Centre, Mumbai. (author)

  9. Sr/Y separation by supported liquid membranes based on nuclear track micro filters

    International Nuclear Information System (INIS)

    First results of experiments concerning the preparation of a Y-90 generator are presented. The aim of this work is to prepare a rather cost-effective and easy to maintain Y-90 generator that produces Y-90 solutions of sufficient purity for their subsequent application in radionuclide therapy. Besides the need for high purity of the Y-90 solutions, it has to be taken into account that high activities are involved (up to 2 Ci Sr-90). Consequently, materials with very good radiation stability must be used for the construction of the generator. Nuclear track micro filters (NTMFs) prepared from polyimide foils are renowned for their outstanding radiolytical and chemical stability. In addition to that they have the distinct advantage that pore size and porosity can be chosen and optimized for each application. The NTMFs are used as supported liquid membranes (SLM) after impregnating them with a 1:1 mixture of bis-(2-ethylhexyl)-phosphate (HDEHP) and tributylphosphate (TBP). Y-90 separation from its parent Sr-90 is achieved by its selective transport through the pores of the impregnated NTMF. The Y-90 activity of the prepared solutions is determined by means of Cerenkov-counting, the Sr-90 content is calculated after determining the activity of an internal standard, namely Sr-85, by low-level gamma-spectrometry. It was shown that a separation of Y-90 and Sr-90 using NTMFs impregnated with an appropriate extractant is possible

  10. Solid/liquid extraction equilibria of phenolic compounds with trioctylphosphine oxide impregnated in polymeric membranes.

    Science.gov (United States)

    Praveen, Prashant; Loh, Kai-Chee

    2016-06-01

    Trioctylphosphine oxide based extractant impregnated membranes (EIM) were used for extraction of phenol and its methyl, hydroxyl and chloride substituted derivatives. The distribution coefficients of the phenols varied from 2 to 234, in the order of 1-napthol > p-chlorophenol > m-cresol > p-cresol > o-cresol > phenol > catechol > pyrogallol > hydroquinone, when initial phenols loadings was varied in 100-2000 mg/L. An extraction model, based on the law of mass action, was formulated to predict the equilibrium distribution of the phenols. The model was in excellent agreement (R(2) > 0.97) with the experimental results at low phenols concentrations ( 0.95), which signified high mass transfer resistance in the EIMs. Examination of the effects of ring substitution on equilibrium, and bivariate statistical analysis between the amounts of phenols extracted into the EIMs and factors affecting phenols interaction with TOPO, indicated the dominant role of hydrophobicity in equilibrium determination. These results improve understanding of the solid/liquid equilibrium process between phenols and the EIMs, and these will be useful in designing phenol recovery process from wastewater. PMID:27031803

  11. 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

    2016-01-01

    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. PMID:27533852

  12. Application of hollow fiber supported liquid membrane for the separation of americium from the analytical waste

    International Nuclear Information System (INIS)

    Americium from analytical solid waste containing U and metallic impurities was separated using hollow fiber supported liquid membrane (HFSLM) technique impregnated with DHOA-TODGA from nitric acid medium. An aliquot of 5 g of the solid waste containing Am (19.95 mg) as minor actinide and of U (2,588 mg), Fe (1,360 mg), Ca (1,810 mg) and Na (3,130 mg) as major impurities was processed. The feed solution obtained after the dissolution of the residue in ∼4 M HNO3 was passed through HFSLM module. In the first stage using 1 M DHOA-dodecane was used for the separation of Am from other impurities. Though, majority of the elements were separated in this cycle, Ca was co extracted along with the americium. CMPO extraction chromatographic technique was used for further separation of americium from Ca. Significant decontamination factors were achieved in this three step separation process with respect to U, Fe, Na and Ca with ∼77 % recovery of americium. (author)

  13. Electrochemical reduction of aromatic ketones in 1-butyl-3-methylimidazolium-based ionic liquids in the presence of carbon dioxide: the influence of the ketone substituent and the ionic liquid anion on bulk electrolysis product distribution.

    Science.gov (United States)

    Zhao, Shu-Feng; Horne, Mike; Bond, Alan M; Zhang, Jie

    2015-07-15

    Electrochemical reduction of aromatic ketones, including acetophenone, benzophenone and 4-phenylbenzophenone, has been undertaken in 1-butyl-3-methylimidazolium-based ionic liquids containing tetrafluoroborate ([BF4](-)), trifluoromethanesulfonate ([TfO](-)) and tris(pentafluoroethyl)trifluorophosphate ([FAP](-)) anions in the presence of carbon dioxide in order to investigate the ketone substituent effect and the influence of the acidic proton on the imidazolium cation (C2-H) on bulk electrolysis product distribution. For acetophenone, the minor products were dimers (50%) derived from proton coupled electron transfer reactions involving the electrogenerated radical anions and C2-H. In the cases of both acetophenone and benzophenone, the product distribution is essentially independent of the ionic liquid anion. By contrast, 4-phenylbenzophenone shows a product distribution that is dependent on the ionic liquid anion. Higher yields of carboxylic acids (∼40%) are obtained with [TfO](-) and [FAP](-) anions because in these ionic liquids the C2-H is less acidic, making the formation of alcohol less favourable. In comparison with benzophenone, a higher yield of carboxylic acid (>30% versus ∼15%) was obtained with 4-phenylbenzophenone in all ionic liquids due to the weaker basicity of 4-phenylbenzophenone radical anion. PMID:26136079

  14. Studies on transport of thorium (IV) from chloride medium across liquid membrane containing Cyanex 923 as carrier

    International Nuclear Information System (INIS)

    India has large thorium deposits, which is proposed to be exploited for its energy needs in future. Liquid membrane technique is better alternative and more suitable for the separation and recovery of the desired metal ions from its lean sources. During Thorex process, a significant amount of liquid waste is generated in HCL medium arising from analytical method employed for determining the iron contamination in the U product by spectrophotometry. Since this waste contains thorium, there is need for a suitable method to recover these nuclear materials from analytical waste

  15. Synthesis and properties of ferromagnetic Fe-based (Fe, Ni, Co)–Mo–P–C–B bulk metallic glasses with large supercooled liquid region

    Energy Technology Data Exchange (ETDEWEB)

    Jia, Xingjie; Li, Yanhui [School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China); Wang, Hao [WPI, Advanced Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Xie, Guoqiang [School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China); Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Yamaura, Shinichi [Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Zhang, Wei, E-mail: wzhang@dlut.edu.cn [School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China); Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan)

    2015-08-15

    New ferromagnetic Fe-based (Fe, Co, Ni){sub 67.5}Mo{sub 7.5}P{sub 10}C{sub 10}B{sub 5} bulk metallic glasses have been developed based on an Fe{sub 75}P{sub 10}C{sub 10}B{sub 5} alloy. These alloys exhibit large supercooled liquid region of 97–102 K, low glass transition temperature of 727–738 K, high glass-forming ability (GFA) with critical sample diameters of 3–4 mm, and low viscosity values on the order of 10{sup 7} Pa s in the supercooled liquid state. The magnetic and mechanical measurements reveal that the alloys also possess good soft magnetic and mechanical properties, i.e., low coercive force of 3.04−4.37 A/m, rather high saturation magnetization of 0.77−0.83 T, high yield strength of 3344−3463 MPa, and large plastic strain of 0.6−1.1%. In addition, the effects of Mo, Co and Ni addition on the stabilization of supercooled liquid and GFA in the Fe–P–C–B alloy system have been discussed.

  16. Synthesis and properties of ferromagnetic Fe-based (Fe, Ni, Co)–Mo–P–C–B bulk metallic glasses with large supercooled liquid region

    International Nuclear Information System (INIS)

    New ferromagnetic Fe-based (Fe, Co, Ni)67.5Mo7.5P10C10B5 bulk metallic glasses have been developed based on an Fe75P10C10B5 alloy. These alloys exhibit large supercooled liquid region of 97–102 K, low glass transition temperature of 727–738 K, high glass-forming ability (GFA) with critical sample diameters of 3–4 mm, and low viscosity values on the order of 107 Pa s in the supercooled liquid state. The magnetic and mechanical measurements reveal that the alloys also possess good soft magnetic and mechanical properties, i.e., low coercive force of 3.04−4.37 A/m, rather high saturation magnetization of 0.77−0.83 T, high yield strength of 3344−3463 MPa, and large plastic strain of 0.6−1.1%. In addition, the effects of Mo, Co and Ni addition on the stabilization of supercooled liquid and GFA in the Fe–P–C–B alloy system have been discussed

  17. Bulk chlorine uptake by polyamide active layers of thin-film composite membranes upon exposure to free chlorine-kinetics, mechanisms, and modeling.

    Science.gov (United States)

    Powell, Joshua; Luh, Jeanne; Coronell, Orlando

    2014-01-01

    We studied the volume-averaged chlorine (Cl) uptake into the bulk region of the aromatic polyamide active layer of a reverse osmosis membrane upon exposure to free chlorine. Volume-averaged measurements were obtained using Rutherford backscattering spectrometry with samples prepared at a range of free chlorine concentrations, exposure times, and mixing, rinsing, and pH conditions. Our volume-averaged measurements complement previous studies that have quantified Cl uptake at the active layer surface (top ≈ 7 nm) and advance the mechanistic understanding of Cl uptake by aromatic polyamide active layers. Our results show that surface Cl uptake is representative of and underestimates volume-averaged Cl uptake under acidic conditions and alkaline conditions, respectively. Our results also support that (i) under acidic conditions, N-chlorination followed by Orton rearrangement is the dominant Cl uptake mechanism with N-chlorination as the rate-limiting step; (ii) under alkaline conditions, N-chlorination and dechlorination of N-chlorinated amide links by hydroxyl ion are the two dominant processes; and (iii) under neutral pH conditions, the rates of N-chlorination and Orton rearrangement are comparable. We propose a kinetic model that satisfactorily describes Cl uptake under acidic and alkaline conditions, with the largest discrepancies between model and experiment occurring under alkaline conditions at relatively high chlorine exposures. PMID:24506252

  18. High temperature ceramic membrane reactors for coal liquid upgrading. Quarterly report No. 10, December 21, 1991--March 20, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Tsotsis, T.T.

    1992-07-01

    In this project we will study a novel process concept, i.e., the use of ceramic membrane reactors in upgrading of coal model compounds and coal derived liquids. In general terms, the USC research team is responsible for constructing and operating the membrane reactor apparatus and for testing various inorganic membranes for the upgrading of coal derived asphaltenes and coal model compounds. The USC effort will involve the principal investigator of this project and two graduate research assistants. The ALCOA team is responsible for the preparation of the inorganic membranes, for construction and testing of the ceramic membrane modules, and for measurement of their transport properties. The ALCOA research effort will involve Dr. Paul K. T. Liu, who is the project manager of the ALCOA research team, an engineer and a technician. UNOCAL`s contribution will be limited to overall technical assistance in catalyst preparation and the operation of the laboratory upgrading membrane reactor and for analytical back-up and expertise in oil analysis and materials characterization. UNOCAL is a no-cost contractor but will be involved in all aspects of the project, as deemed appropriate.

  19. Studies on the separation of Ir(IV) and Ru(III) from chloride solutions using supported liquid membrane technique

    International Nuclear Information System (INIS)

    Due to limited resources, the gap between supply and demand of the platinum group metals (Rh, Ru, Ir, Pt, Pd) is increasing. Recycling after their use is an important resource in seeking to meet growing demand for these metals. Supported liquid membrane (SLM) technique is one of the promising techniques for the separation and recovery of species from their very dilute solutions where under similar conditions other conventional techniques are not economical. In the present work the transfer of ruthenium(III) from chloride solutions across supported liquid membrane and its separation from iridium(IV) was studied. Cyanex 923 (C923) and Alamine 336 (A336) as ion carriers were applied. Based on the results obtained in solvent extraction experiments it is expected that the presence of the Ru in the source phase will not affect on the transport of Ir(IV). Moreover, when both metals were present in the mixture the extraction of Ru decreased

  20. 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.

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

    International Nuclear Information System (INIS)

    Graphical abstract: Display Omitted Highlights: → Amphiphilic carbon nanofiber membrane employed in electro-synthesis. → Triple phase boundary process within a carbon membrane. → Electrochemical deuteration in a liquid|liquid micro-reactor system. → Triple phase boundary reaction zone effects in electro-synthesis. - Abstract: An amphiphilic carbon nanofibre membrane electrode (ca. 50 nm fibre diameter, 50-100 μm membrane thickness) is employed as an active working electrode and separator between an aqueous electrolyte phase (with reference and counter electrode) and an immiscible organic acetonitrile phase (containing only the redox active material). Potential control is achieved with a reference and counter electrode located in the aqueous electrolyte phase, but the electrolysis is conducted in the organic acetonitrile phase in the absence of intentionally added supporting electrolyte. For the one-electron oxidation of n-butylferrocene coupled to perchlorate anion transfer from aqueous to organic phase effective electrolysis is demonstrated with an apparent mass transfer coefficient of m = 4 x 10-5 m s-1 and electrolysis of typically 1 mg n-butylferrocene in a 100 μL volume. For the two-electron reduction of tetraethyl-ethylenetetracarboxylate the apparent mass transfer coefficient m = 4 x 10-6 m s-1 is lower due to a less extended triple phase boundary reaction zone in the carbon nanofibre membrane. Nevertheless, effective electrolysis of up to 6 mg tetraethyl-ethylenetetracarboxylate in a 100 μL volume is demonstrated. Deuterated products are formed in the presence of D2O electrolyte media. The triple phase boundary dominated mechanism and future microreactor design improvements are discussed.

  2. Effect of tetraalkylammonium cations on amperometric detection of heparin at a polarized water/ionic liquid membrane interface

    Czech Academy of Sciences Publication Activity Database

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

    Ústí nad Labem : Best servis, 2013 - (Navrátil, T.; Fojta, M.; Pecková, K.), s. 167-171 ISBN 978-80-905221-1-4. [Moderní elektrochemické metody /33./. Jetřichovice (CZ), 20.05.2013-24.05.2013] R&D Projects: GA ČR GAP206/11/0707 Institutional support: RVO:61388955 Keywords : Heparin * Ionic liquid membrane * Amperometric detection Subject RIV: CG - Electrochemistry

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

    OpenAIRE

    Cervera Padrell, Albert Emili; Morthensen, Sofie Thage; Lewandowski, Daniel Jacob; Skovby, Tommy; Kiil, Søren; Gernaey, Krist V

    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, obtained in continuous mode by a Grignard reaction in THF, reacted with acidic water to produce partially miscible organic and aqueous phases containing Mg salts. Despite the partial THF–water miscibil...

  4. Uranium permeation across supported liquid membrane using dinonyl phenyl phosphoric acid (DNPPA) and its mixture with neutral donors as carriers

    International Nuclear Information System (INIS)

    Dinonyl phenyl phosphoric acid (DNPPA), a close analog of D2EHPA is widely used for recovery of uranium from phosphoric acid medium by solvent extraction technique. The literature suggested that no reports are available on uranium transport from acidic medium using DNPPA as carrier solvent. Permeation of U(VI) from nitric acid medium across supported liquid membrane (SLM) has been studied under varying experimental conditions, viz. feed, carrier and receiver phase compositions

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

    International Nuclear Information System (INIS)

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

  6. Uphill transport driven by hydrolysis of a complex partitioned into a liquid membrane: application to the preconcentration of arsenic

    Energy Technology Data Exchange (ETDEWEB)

    Cox, J.A.; Bhatnagar, A.

    1988-01-01

    AsI/sub 3/ is demonstrated to partition from a 9 M HCl, 0.10 M KI, 0.10 M asorbic acid solution into kerosene and dodecane membranes which do not contain complexing agents. Subsequent hydrolysis at the membrane receiver interface causes a transport of As against its concentration gradient. A 60 minute experiment with a 4 mL receiver solution and 200 mL sample permits the preconcentration of As by a factor of 16 +- 0.5. The interferences of aluminum and phosphate on the graphite furnace atomic absorption spectrometric determination of As are eliminated. This transport mechanism, which has not been previously reported, may allow the range of species which can be preconcentrated by transport across supported liquid membranes to be significantly extended.

  7. The bulk viscosity of a symmetrical Lennard--Jones mixture above and at liquid--liquid coexistence: A computer simulation study

    OpenAIRE

    Das, Subir K.; Horbach, Jürgen; Binder, Kurt

    2004-01-01

    A Lennard--Jones model of a binary dense liquid (A,B) with a symmetrical miscibility gap is investigated by means of computer simulation methods. Semigrand--canonical Monte Carlo simulations yield the phase diagram in the $T$--$x$ plane ($T$: temperature, $x$: concentration of A or B particles) as well as equilibrated configurations at coexistence. Then Molecular Dynamics simulations use these configurations to determine static properties (isothermal compressibility $\\kappa_T$ and concentrati...

  8. Novel Ceramic-Polymer Composite Membranes for the Separation of Hazardous Liquid Waste; FINAL

    International Nuclear Information System (INIS)

    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

  9. 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.

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

    International Nuclear Information System (INIS)

    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

  11. 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

  12. Hunting liquid micro-pockets in snow and ice: Phase transition in salt solutions at the bulk and interface with X-ray photoelectron spectroscopy.

    Science.gov (United States)

    Bartels-Rausch, Thorsten; Orlando, Fabrizio; Kong, Xiangrui; Waldner, Astrid; Artiglia, Luca; Ammann, Markus; Huthwelker, Thomas

    2016-04-01

    Sea salt, and in particular chloride, is an important reactant in the atmosphere. Chloride in air-borne sea salt aerosol is - once chemically converted to a molecular halogen (Cl2, BrCl) and released to the atmosphere - well known as important atmospheric reactant, driving large-scale changes to the atmospheric composition and in particular to ozone levels in remote areas, but also in coastal mega cities. Similar chemistry has been proposed for sea salt deposits in polar snow covers. A crucial factor determining the overall reactivity is the local physical environment of the chloride ion. For example, the reactivity of liquid aerosols decreases significantly upon crystallization. Surprisingly, the phases of NaCl-containing systems are still under debate, partially due to the limited availability of in situ measurements directly probing the local environment at the surface of frozen NaCl-water binary systems. Using core electron spectroscopy of the oxygen atoms in water, we previously showed that these systems follow the phase rules at the air-ice interface. This finding contrasts some earlier observations, where the presence of liquid below the eutectic point of bulk solutions was postulated. In the present study, we present new electron yield near-edge X-ray absorption fine structure spectroscopy (NEXAFS) data obtained at near-ambient pressures up to 20 mbar of NaCl frozen solutions. The method is sensitive to small changes in the local environment of the chlorine atom. The measurements were performed at the PHOENIX beamline at SLS. The study indicates frapant differences in the phases of NaCl - water mixtures at temperatures blow the freezing point for the surface of the ice vs. the bulk. This has significant impact on modelling chemical reactions in snow or ice and it's environmental consequences.

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

    International Nuclear Information System (INIS)

    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−1, and demonstrated good linearity of R2 from 0.9944 to 0.9997 for the four derivatized estrogens. The lower detection limits obtained were 3–7 pg mL−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

  14. Measurement of wall relaxation times of polarized Helium-3 in bulk liquid Helium-4 for the neutron electric dipole moment experiment

    Science.gov (United States)

    Yoder, Jacob

    The Neutron Electric Dipole Moment (nEDM) experiment that will take place at the Spallation Neutron Source (SNS) in Oak Ridge, Tennessee will measure the electric dipole moment (EDM) of the neutron with a precision of order 10-28 e-cm, utilizing spin-polarized 3He in bulk liquid 4He to detect neutron precession in a 10 mG magnetic field and 50 kV/cm electric field. Since depolarized 3He will produce a background, relaxation of the polarized 3He, characterized by the probability of depolarization per bounce, Pd, was measured for materials that will be in contact with polarized 3He. Depolarization probabilities were determined from measurements of the longitudinal relaxation time of polarized 3He in bulk liquid 4He inside an acrylic cell coated with the wavelength shifter deuterated tetraphenyl butadiene (d-TPB), which will be used to coat the nEDM measurement cell. Relaxation measurements were also performed while rods, made from plumbing material Torlon and valve bellows material BeCu, were present in the cell. The BeCu was coated with Pyralin resin prior to relaxation measurements, while relaxation measurements were performed both before and after the Torlon rod was coated with Pyralin resin. The depolarization probabilities were found to be Pd-TPBd <1.32x10-7 PBareTorlon d=1.01+/-0.08 x10-6 PCoatedTorlon d=2.5+/-0.1 x10-7 PCoatedBeCu d=7.9+/-0.3 x10-7 The relaxation rates extrapolated from the observed values of Pd for d-TPB, coated Torlon, and coated BeCu in the nEDM apparatus were found to be consistent with design goals.

  15. Sensitivity enhancement in direct coupling of supported liquid membrane extractions to capillary electrophoresis by means of transient isotachophoresis and large electrokinetic injections

    OpenAIRE

    Pantůčková, P. (Pavla); Kubáň, P. (Pavel); Boček, P. (Petr)

    2015-01-01

    Enhanced sensitivity for determination of basic drugs in body fluids was achieved by in-line coupling of extraction across supported liquid membrane (SLM) to large electrokinetic injection and transient isotachophoresis-capillary zone electrophoresis in commercial capillary electrophoresis instrument.

  16. Production of CeO2 Nanoparticles by Method of Laser Ablation of Bulk Metallic Cerium Targets in Liquid

    Science.gov (United States)

    Svetlichnyi, V. A.; Lapin, I. N.

    2016-03-01

    The method of pulsed laser ablation in liquid was used to synthesize dispersions of cerium oxide nanoparticles when subjecting a metallic cerium target in water and alcohol to basic frequency radiation of the nanosecond Nd:YAG laser (1064 nm, 7 ns, 20 Hz). Researchers have studied the effect of laser radiation parameters, duration of impact, and optical scheme of experiment on the ablation process. The average rate of nanoparticle production was 50 mg/h in water and 25 mg/h in alcohol. Researchers have studied the size characteristics and crystalline structure of the nanoparticles produced. The particles have bimodal size distribution with 6 nm and 25 nm maximums. The average crystallite size is 17-19 nm. The crystalline structure of nanoparticles, namely cubic cerium oxide (fluorite structure), space group Fm-3m, is confirmed by the X-ray diffraction data, as well as optical absorption spectra and Raman spectroscopy.

  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. 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.

  19. Simultaneous measurement of speed of sound, thermal diffusivity, and bulk viscosity of 1-ethyl-3-methylimidazolium-based ionic liquids using laser-induced gratings.

    Science.gov (United States)

    Kozlov, Dimitrii N; Kiefer, Johannes; Seeger, Thomas; Fröba, Andreas P; Leipertz, Alfred

    2014-12-11

    The technique of laser-induced gratings (LIGs) has been applied to the simultaneous determination of speed of sound and thermal diffusivity of four 1-ethyl-3-methylimidazolium ([EMIm])-based room temperature ionic liquids (RTILs)-[EMIm][N(CN)2], [EMIm][MeSO3], [EMIm][C(CN)3], and [EMIm][NTf2]-at ambient pressure (1 bar (0.1 MPa)) and temperature (28 °C (301 K)). Transient laser-induced gratings were created as a result of thermalization of a quasi-resonant excitation of highly lying combinational vibrational states of the RTIL molecules and electrostrictive compression of the liquid by radiation of a pulse-repetitive Q-switched Nd:YAG pump laser (1064 nm). The LIGs temporal evolution was recorded using Bragg diffraction of the radiation from a continuous-wave probe laser (532 nm). By fitting the temporal profiles of the LIG signals, the speed of sound and thermal diffusivity were determined, and the isentropic compressibility and thermal conductivity were calculated. Independently, the special experimental arrangement allowed the measurement of the damping of the laser-excited acoustic waves and the derivation of the RTIL bulk viscosity for the first time. PMID:25415848

  20. 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

  1. 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%. PMID:26593494

  2. Development of a surfactant liquid membrane extraction process for the cleansing of industrial aqueous effluents containing metallic cation traces

    International Nuclear Information System (INIS)

    The purpose of this work was to develop a process of surfactant liquid membrane extraction to purify industrial waste solution containing Cu(II), Fe(III), and Zn(II) (about 0,1 g/L). The extractant is the ammonium salt of Cyanex 306 and Aliquat 336. The first part of this work deals with the study of the liquid-liquid extraction of the metals. The efficiency of the extractant has been shown for the extraction of each metal alone and for Cu(II) and Zn(II) in the case of a mixture of the three metals. During this study we have observed that Fe(III) is reduced to Fe(II) (which is not extracted by the salt of Cyanex 301) in presence of Cu(II) and the quaternary ammonium salt (Aliquat 336). The optimisation of the experimental conditions for the discontinuous surfactant liquid membrane process led us to choose the following composition of the emulsion: 1,5 % of Cyanex 301 salt, 2,5 % of ECA 4360, dodecan. The internal phase is an aqueous solution containing 3,5 mol/L of NaOH and 0,5 mol/L tri-ethanolamin The residual concentration of Cu(II) and Zn(II) in the external phase is very low. In the case of iron, only 60 % are extracted because of the reduction phenomenon (10 % in liquid-liquid extraction). The realisation of the continuous process in pulsed column, after optimisation of hydrodynamics conditions, leads to similar results. In stationary conditions, we obtain a raffinate containing less than 0,5 mg/L of Cu(II) and Zn(II) and 36 mg/L of iron. The internal phase contains about 2 g/L of Cu(II) an Zn(II). We tried and minimize the reduction of Fe(III) in surfactant liquid membrane process. Less than 16 % of iron cannot be reduced. This leads to a purification of only 84 % In the basis of these results, processes of purification have been proposed for effluents of various composition. They enable to purify the effluent and besides to concentrate the pollutants about twenty times. (author)

  3. Development of Metal Organic Framework Containing Membranes For Gas and Liquid Separations

    OpenAIRE

    Basu, Subhankar

    2011-01-01

    The growth of the market for gas separations (GS) is expected to increase considerably in the years to come. Most of this expansion is dependent on the continued development of more efficient membranes. The current membrane technology for GS is mainly based on polymeric membranes, especially cellulose acetate and polyimide (PI). However, those are subject to a limiting trade-off between the productivity (permeability) and efficiency (selectivity). While other materials with high GS performanc...

  4. Analysis of the minority crystalline phases in bulk superconducting MgB2 obtained by reactive liquid Mg infiltration

    International Nuclear Information System (INIS)

    The preparation of MgB2 starting from the elements (in situ process), when performed in conjunction with the Mg liquid infiltration process, gives rise to very high dense manufacts, with outstanding mechanical and superconducting characteristics. The infiltration technique is particularly suitable when realized into preforms of crystalline boron powders of grain size up to about 100 μm; however, the resulting products typically present a microstructure characterized by a composite morphology, indicating a inhomogeneous distribution of different crystalline phases. In this paper the composition and the morphology of typical products has been analyzed with several techniques, including X-ray powder diffraction (XRPD), scanning electron microscopy and X-ray fluorescence microanalysis, aiming to quantify the (spatial) distribution of crystalline phases and the presence of minority phases different from the MgB2. The minority phases that are commonly present in the MgB2 infiltration preparation are residual elemental magnesium and a new boron-rich magnesium boride phase (Mg2B25), recently discovered and structurally characterized (by unconventional XRPD methods) by our group. We have analyzed the common morphological features of typical MgB2 samples, and cross-checked the analytical results obtained from different experimental techniques. Our results show that the new Mg2B25 phase amounts to less than 10 molar % of the MgB2 entire product, and that it is mainly concentrated, as submicronic inclusions (inside the larger crystalline MgB2 grains) where it can reach concentration values up to 40 molar %

  5. 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. PMID:27178937

  6. Pervaporation from a dense membrane: roles of permeant-membrane interactions, Kelvin effect, and membrane swelling.

    Science.gov (United States)

    Sharma, Ashutosh; Thampi, Sumesh P; Suggala, Satyanarayana V; Bhattacharya, Prashant K

    2004-05-25

    Dense polymeric membranes with extremely small pores in the form of free volume are used widely in the pervaporative separation of liquid mixtures. The membrane permeation of a component followed by its vaporization on the opposite face is governed by the solubility and downstream pressure. We measured the evaporative flux of pure methanol and 2-propanol using dense membranes with different free volumes and different affinities (wettabilities and solubilities) for the permeant. Interestingly, the evaporative flux for different membranes vanished substantially (10-75%) below the equilibrium vapor pressure in the bulk. The discrepancy was larger for a smaller pore size and for more wettable membranes (higher positive spreading coefficients). This observation, which cannot be explained by the existing (mostly solution-diffusion type) models ofpervaporation, suggests an important role for the membrane-permeant interactions in nanopores that can lower the equilibrium vapor pressure. The pore sizes, as estimated from the positron annihilation, ranged from 0.2 to 0.6 nm for the dry membranes. Solubilities of methanol in different composite membranes were estimated from the Flory-Huggins theory. The interaction parameter was obtained from the surface properties measured by the contact angle goniometry in conjunction with the acid-base theory of polar surface interactions. For the membranes examined, the increase in the "wet" pore volume due to membrane swelling correlates almost linearly with the solubility of methanol in these membranes. Indeed, the observations are found to be consistent with the lowering of the equilibrium vapor pressure on the basis of the Kelvin equation. Thus, a higher solubility or selectivity of a membrane also implies stronger permeant-membrane interactions and a greater retention of the permeant by the membrane, thus decreasing its evaporative flux. This observation has important implications for the interpretation of existing experiments and in

  7. Studies on the Use of Supported Liquid Membrane Technique for Removal of Heavy Metals from Water Effluents

    International Nuclear Information System (INIS)

    The present work is directed to develop, assess and establish different systems for the removal and recovery of Co, Ni, Zn and Cd from aqueous solutions using supported liquid membrane (SLM) technique. The individual permeation of Co(II) and Ni(II) from aqueous chloride solutions through SLM using CYANEX 301 in kerosene supported on cellulose acetate membrane was studied based on the optimum conditions for separation obtained by liquid-liquid extraction experiments. Application studies of the investigated system were carried out on the permeation of four heavy elements (Co(II), Ni(II), Zn(II) and Cd(II) ) of equal concentrations when mixed together in real water samples from different origins. For this purpose, samples from Ismailia canal, El-Manzala lake, sea water and drinking water were selected for these experiments. The results obtained show that complete removal of Zn(II) from aqueous chloride medium of ph 3 from El-Manzala lake water is obtained at different temperature degrees and the removal of a large amounts of Co(II), Cd(II) and Ni(II) from drinking water is also possible.

  8. Determination of 2-ethylhexyl 4-(dimethylamino) benzoate using membrane-assisted liquid-liquid extraction and gas chromatography-mass spectrometric detection.

    Science.gov (United States)

    March, J G; Genestar, C; Simonet, B M

    2009-06-01

    A flow-cell for micro-porous membrane liquid-liquid extraction with a sheet membrane was used to extract 2-ethylhexyl 4-(dimethylamino) benzoate (EDB) from urine of solar-cream users and spiked wine samples. The cell enabled the target analyte to be extracted from 7.9 mL of donor solution into 200 microL of acceptor solution (decane). After extraction, the acceptor solution was transferred to a micro-vial for GC-MS analysis without derivation. In this work, variables affecting the enrichment factor were also studied, such as organic solvent, extraction time, recirculation flow of the donor solution through the donor chamber, presence of potassium chloride and ethanol in the donor solution and pH. The method has been evaluated in terms of linearity, sensitivity, precision, limits of detection and quantification and extraction efficiency. Limits of quantification were 1 and 3 microg L(-1) EDB for urine and wine, respectively. Quantitative analysis has been carried out by applying the method of standard additions. Within- and between-day relative standard deviations were lower than 12% and 20%, respectively. EDB was found in the urine of users of cream containing EDB in the concentration interval 1.2-7.2 microg L(-1). Therefore, this provides evidence of EDB dermal absorption and subsequent excretion through the urinary tract. EDB was not found in the analysed wine samples. PMID:19347661

  9. 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

    2015-01-01

    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. PMID:26189604

  10. Enhancement of critical current density of liquid-infiltration-processed Y–Ba–Cu–O bulk superconductors using milled Y2BaCuO5 powder

    International Nuclear Information System (INIS)

    The size effects of a precursor Y2BaCuO5 (Y211) powder on the microstructure and critical current density (Jc) of liquid infiltration growth (LIG)-processed YBa2Cu3O7−y (Y123) bulk superconductors were investigated in terms of milling time (t). Y211 powders were attrition-milled for 0–10 h in 2 h increments at a fixed rotation speed of 400 rpm. Y211 pre-forms were made by pelletizing the milled Y211 powders followed by subsequent sintering, after which an LIG process with top seeding was applied to the Y211/Ba3Cu5O8 (Y035) pre-forms. Spherical pores were observed in all LIG-processed Y123 samples and the pore density gradually decreased as t increased from 0 to 8 h. In addition to the reduced pore density, the Y211 particle size in the final Y123 products also decreased with increasing t. As t increased further to 10 h, unexpected Y211 coarsening and large pore evolutions were observed. The magnetic susceptibility–temperature curves showed that the onset superconducting transition temperature (Tc,onset) of all samples was the same (91.5 K), but the transition width became greater as t increased. The Jc of the Y123 bulk superconductors fabricated in this study was observed to correlate well with t of the Y211 precursor powder. The maximum Jc of 1.0 × 105 A cm−2 (at 77 K, 0 T) was achieved at t = 8 h, which is attributed to the reduction in pore density and Y211 particle size. The prolonged milling time of t = 10 h decreased the Jc of the LIG-processed Y123 superconductor owing to the evolution of large pores and exaggerated Y211 growth. (paper)

  11. 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.

  12. Full q-space analysis of x-ray scattering of multilamellar membranes at liquid-solid interfaces

    International Nuclear Information System (INIS)

    A method for analyzing the x-ray scattering of a stack of phospholipid membranes at the solid-liquid interface in excess water is presented. It is argued that bilayers near the substrate fluctuate less significantly than the ones away from it and, therefore, make a larger contribution to the specular reflection at the low index Bragg peaks. But the diffuse scattering due to thermal fluctuations corrupts the Bragg peaks at high angles so that the specular contribution is not clearly observable. In the midst the specular reflection and the diffuse scattering cannot be separated easily and must be analyzed simultaneously. The height-difference correlation function derived from a modified Caille theory enables one to simulate the longitudinal and the transverse scans in the same theoretical framework to yield more reliable structural parameters. The theoretical apparatus is successfully applied to the experimental data on DOPC membranes

  13. 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.

  14. Separation of 90Y from 90Sr using hollow fiber supported liquid membrane containing PC-88A as the carrier

    International Nuclear Information System (INIS)

    2-Ethylhexylphosphonic acid -2- ethyl hexylmonoester (PC-88A) has been used as the extractant for Y3+ and Eu3+ (used as a surrogate) from pH solutions where Sr2+ remained inextractable. The relative extraction efficiency of PC-88A towards Y3+ and Sr2+ was investigated from dilute HNO3 media using solvent extraction, as well as hollow fiber supported liquid membrane (HFSLM) methods. A separation method for 90Y from 90Sr + 90Y mixture was developed using HFSLM method and discussed in the present paper. (author)

  15. Vapour Permeation and Sorption in Fluoropolymer Gel Membrane Based on Ionic Liquid 1-Ethyl-3-Methylimidazolium bis(trifluoromethylsulfonyl)Imide

    Czech Academy of Sciences Publication Activity Database

    Morávková, Lenka; Vopička, O.; Vejražka, Jiří; Vychodilová, Hana; Sedláková, Zuzana; Friess, K.; Izák, Pavel

    2014-01-01

    Roč. 68, č. 12 (2014), s. 1739-1746. ISSN 0366-6352 R&D Projects: GA ČR GAP106/10/1194; GA TA ČR TE01020080; GA MŠk(CZ) LD14094; GA MŠk(CZ) LD13018 Grant ostatní: GA ČR(CZ) GA13-32829P Institutional support: RVO:67985858 Keywords : ionic liquid membrane * hydrocarbon removal * volatile organic compound removal Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 1.468, year: 2014

  16. Direct coupling of supported liquid membrane extractions to capillary electrophoresis. Sensitivity enhancement in analyses of untreated complex samples

    Czech Academy of Sciences Publication Activity Database

    Pantůčková, Pavla; Kubáň, Pavel; Boček, Petr

    Brno: Institute of Analytical Chemistry AS CR, 2014 - (Foret, F.; Křenková, J.; Drobníková, I.; Guttman, A.; Klepárník, K.), s. 346-348 ISBN 978-80-904959-2-0. [CECE 2014. International Interdisciplinary Meeting on Bioanalysis /11./. Brno (CZ), 20.10.2014-22.10.2014] R&D Projects: GA ČR(CZ) GA13-05762S Institutional support: RVO:68081715 Keywords : capillary electrophoresis * supported liquid membrane * transient isotachophoresis Subject RIV: CB - Analytical Chemistry, Separation http://www.ce-ce.org/CECE2014/CECE%202014%20proceedings_full.pdf

  17. Penicillin G extraction from model media using an emulsion liquid membrane: a theoretical model of product decomposition.

    Science.gov (United States)

    Lee, K H; Lee, S C; Lee, W K

    1994-04-01

    To confirm the applicability for the extraction of penicillin G by an emulsion liquid membrane (ELM), the degree of decomposition of penicillin G during extraction was theoretically calculated. Decomposition was less than 1% provided that the initial sodium carbonate concentration in the internal phase was correctly determined, which proved the applicability of the ELM process. The procedure to determine the initial carbonate concentration in the internal phase was also described in order that the pH in the internal phase should be within the relatively stable range for penicillin G at the end of the extraction. PMID:7764816

  18. 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.

  19. 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. PMID:20843596

  20. NOVEL CERAMIC-POLYMER COMPOSITE MEMBRANES FOR THE SEPARATION OF HAZARDOUS LIQUID WASTE

    Science.gov (United States)

    There is a growing need in the fields of remediation, hazardous chemical waste treatment, water treatment and pollution prevention for new processes capable of selectively separating and concentrating a target species, often present in dilute solution. Although membrane systems h...

  1. Persistent effectivity of gas plasma-treated, long time-stored liquid on epithelial cell adhesion capacity and membrane morphology.

    Directory of Open Access Journals (Sweden)

    Maxi Hoentsch

    Full Text Available Research in plasma medicine includes a major interest in understanding gas plasma-cell interactions. The immediate application of gas plasma in vitro inhibits cell attachment, vitality and cell-cell contacts via the liquid. Interestingly, in our novel experiments described here we found that the liquid-mediated plasma effect is long-lasting after storage up to seven days; i. e. the liquid preserves the characteristics once induced by the argon plasma. Therefore, the complete Dulbecco's Modified Eagle cell culture medium was argon plasma-treated (atmospheric pressure, kINPen09 for 60 s, stored for several days (1, 4 and 7 d at 37°C and added to a confluent mouse hepatocyte epithelial cell (mHepR1 monolayer. Impaired tight junction architecture as well as shortened microvilli on the cell membrane could be observed, which was accompanied by the loss of cell adhesion capacity. Online-monitoring of vital cells revealed a reduced cell respiration. Our first time-dependent analysis of plasma-treated medium revealed that temperature, hydrogen peroxide production, pH and oxygen content can be excluded as initiators of cell physiological and morphological changes. The here observed persisting biological effects in plasma-treated liquids could open new medical applications in dentistry and orthopaedics.

  2. Persistent effectivity of gas plasma-treated, long time-stored liquid on epithelial cell adhesion capacity and membrane morphology.

    Science.gov (United States)

    Hoentsch, Maxi; Bussiahn, René; Rebl, Henrike; Bergemann, Claudia; Eggert, Martin; Frank, Marcus; von Woedtke, Thomas; Nebe, Barbara

    2014-01-01

    Research in plasma medicine includes a major interest in understanding gas plasma-cell interactions. The immediate application of gas plasma in vitro inhibits cell attachment, vitality and cell-cell contacts via the liquid. Interestingly, in our novel experiments described here we found that the liquid-mediated plasma effect is long-lasting after storage up to seven days; i. e. the liquid preserves the characteristics once induced by the argon plasma. Therefore, the complete Dulbecco's Modified Eagle cell culture medium was argon plasma-treated (atmospheric pressure, kINPen09) for 60 s, stored for several days (1, 4 and 7 d) at 37°C and added to a confluent mouse hepatocyte epithelial cell (mHepR1) monolayer. Impaired tight junction architecture as well as shortened microvilli on the cell membrane could be observed, which was accompanied by the loss of cell adhesion capacity. Online-monitoring of vital cells revealed a reduced cell respiration. Our first time-dependent analysis of plasma-treated medium revealed that temperature, hydrogen peroxide production, pH and oxygen content can be excluded as initiators of cell physiological and morphological changes. The here observed persisting biological effects in plasma-treated liquids could open new medical applications in dentistry and orthopaedics. PMID:25170906

  3. Monitoring of N-methyl carbamate pesticide residues in water using hollow fibre supported liquid membrane and solid phase extraction

    Science.gov (United States)

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

    The aim of this work was to develop a method for the determination of N-methyl carbamates in water involving hollow fibre supported liquid membrane (HFSLM) and solid phase extraction (SPE) as sample preparation methods. Four N-methyl carbamate pesticides, aldicarb, carbaryl, carbofuran and methiocarb sulfoxide, were simultaneously extracted and analysed by a liquid chromatograph with a diode array detector (LC-UV/DAD) and a liquid chromatograph coupled to a ion trap quadrupole mass spectrometer (LC-ESI-MS). The high performance liquid chromatography (HPLC) separation of carabamate extracts was performed on a C18 column with water-acetonitrile as the mobile phase. The mass spectrometry analyses were carried out in the positive mode, operating under both the selected ion monitoring (SIM) and full scan modes. The solid phase recoveries of the extracts ranged between 8% and 98%, with aldicarb having the highest recoveries, followed by carbaryl, carbofuran and methiocarb had the lowest recovery. The HFSLM recovery ranged between 8% and 58% and the order of recovery was similar to the SPE trend. Factors controlling the efficiency of the HFSLM extraction such as sample pH, stripping phase pH, enrichment time, stirring speed as well as organic solvent used for entrapment of analytes, were optimised to achieve the highest enrichment factors.

  4. Influence of radiation on liquid content of plasma membranes of liver cells

    International Nuclear Information System (INIS)

    The level of total phospholipids decreases, a cholesterol/phospholipid molar coefficient increases, and lipid/protein ratio in plasma membranes of liver cells decreases at early times following total-body X-irradiation of rats (LDsub(50/30)). Changes in individual phospholipids were differently directed. A possible correlation between the data obtained and the structural-functional status of the surface membrane is discussed

  5. Synthesis of magnetic nanoparticles as a draw solute in forward osmosis membrane process for the treatment of radioactive liquid waste

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Heeman; Lee, Kune Woo; Moon, Jei Kwon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-05-15

    These wastes contain about 0.3 ∼ 0.8 wt% of boric acid. It is known that reverse osmosis (RO) membrane can eliminate boron at high pH and boron of 40 ∼ 90% can be removed by RO membrane in pH condition. RO uses hydraulic pressure to oppose, and exceed, the osmotic pressure of an aqueous feed solution containing boric acid. As an emerging technology forward osmosis (FO) has attracted growing interest in wastewater treatment and desalination because FO operates at low or no hydraulic pressures. 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, the challenges of FO still lie in the fabrication of eligible FO membranes and the readily separable draw solutes of high osmotic pressures. Superparamagnetic Fe{sub 3}O{sub 4} nanoparticles can be separated from water by an external magnet field easily. If Fe{sub 3}O{sub 4} nanoparticles are coated with highly soluble organic substances, thus they can be used as a draw solute by concurrently generating high osmotic pressure and easy separation. The carboxylated polyglycerol coated Fe{sub 3}O{sub 4} nanoparticles have been successfully synthesized. The nanoparticles were about 50 nm in diameter and showed the good colloidal stability in aqueous solution. The osmolality and osmotic pressure were enough high to be used as a draw solute in FO. For the future work, we will investigate the performance of our magnetic draw solute in FO to remove boron in the simulated liquid waste.

  6. Synthesis of magnetic nanoparticles as a draw solute in forward osmosis membrane process for the treatment of radioactive liquid waste

    International Nuclear Information System (INIS)

    These wastes contain about 0.3 ∼ 0.8 wt% of boric acid. It is known that reverse osmosis (RO) membrane can eliminate boron at high pH and boron of 40 ∼ 90% can be removed by RO membrane in pH condition. RO uses hydraulic pressure to oppose, and exceed, the osmotic pressure of an aqueous feed solution containing boric acid. As an emerging technology forward osmosis (FO) has attracted growing interest in wastewater treatment and desalination because FO operates at low or no hydraulic pressures. 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, the challenges of FO still lie in the fabrication of eligible FO membranes and the readily separable draw solutes of high osmotic pressures. Superparamagnetic Fe3O4 nanoparticles can be separated from water by an external magnet field easily. If Fe3O4 nanoparticles are coated with highly soluble organic substances, thus they can be used as a draw solute by concurrently generating high osmotic pressure and easy separation. The carboxylated polyglycerol coated Fe3O4 nanoparticles have been successfully synthesized. The nanoparticles were about 50 nm in diameter and showed the good colloidal stability in aqueous solution. The osmolality and osmotic pressure were enough high to be used as a draw solute in FO. For the future work, we will investigate the performance of our magnetic draw solute in FO to remove boron in the simulated liquid waste

  7. 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

  8. Theoretical and computational studies of renewable energy materials: Room temperature ionic liquids and proton exchange membranes

    Science.gov (United States)

    Feng, Shulu

    2011-12-01

    Two kinds of renewable energy materials, room temperature ionic liquids (RTILs) and proton exchange membranes (PEMs), especially Nafion, are studied by computational and theoretical approaches. The ultimate purpose of the present research is to design novel materials to meet the future energy demands. To elucidate the effect of alkyl side chain length and anion on the structure and dynamics of the mixtures, molecular dynamics (MD) simulations of three RTILs/water mixtures at various water mole fractions: 1-butyl-3-methylimidazolium (BMIM+)/BF4-, 1-octyl-3-methylimidazolium (OMIM+)/BF4-, and OMIM +/Cl- are performed. Replacing the BMIM + cation with OMIM+ results in stronger aggregation of the cations as well as a slower diffusion of the anions, and replacing the BF4- anion with Cl- alters the water distribution at low water mole fractions and slows diffusion of the mixtures. Potential experimental manifestations of these behaviors in both cases are provided. Proton solvation properties and transport mechanisms are studied in hydrated Nafion, by using the self-consistent multistate empirical valence bond (SCI-MS-EVB) method. It is found that by stabilizing a more Zundel-like (H5O 2+) structure in the first solvation shells, the solvation of excess protons, as well as the proton hydration structure are both influenced by the sulfonate groups. Hydrate proton-related hydrogen bond networks are observed to be more stable than those with water alone. In order to characterize the nature of the proton transport (PT), diffusive motion, Arrhenius activation energies, and transport pathways are calculated and analyzed. Analysis of diffusive motion suggests that (1) a proton-hopping mechanism dominates the proton transport for the studied water loading levels and (2) there is an obvious degree of anti-correlation between the proton hopping and the vehicular transport. The activation energy drops rapidly with an increasing water content when the water loading level is smaller

  9. 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.

  10. 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.

  11. Extraction of lutetium(III) from aqueous solutions by employing a single fibre-supported liquid membrane.

    Science.gov (United States)

    Trtić-Petrović, Tatjana M; Kumrić, Ksenija R; Dordević, Jelena S; Vladisavljević, Goran T

    2010-07-01

    Transport behaviour of Lu(III) across a polypropylene hollow fibre-supported liquid membrane containing di(2-ethylhexyl)phosphoric acid (DEHPA) in dihexyl ether as a carrier has been studied. The donor phase was LuCl(3) in the buffer solution consisting of 0.2 M sodium acetate at pH 2.5-5.0. A miniaturised system with a single hollow fibre has been operated in a batch mode. The concentration of Lu(III) was determined by indirect voltammetric method using Zn-EDTA complex. The effect of pH and volume of the donor phase, DEHPA concentration in the organic (liquid membrane) phase, the time of extraction and the content of the acceptor phase on the Lu(III) extraction and stripping behaviour was investigated. The results were discussed in terms of the pertraction and removal efficiency, the memory effect and the mean flux of Lu(III). The optimal conditions for the removal of (177)Lu(III) from labelled (177)Lu-radiopharmaceuticals were discussed and identified. The removal efficiency of Lu(III) greater than 99% was achieved at pH of the donor phase between 3.5 and 5.0 using DEHPA concentration in the organic phase of 0.47 M and the ratio of the donor to the acceptor phase of 182. PMID:20506430

  12. Selective extraction of chromium (VI) from multicomponent acidic solutions by emulsion liquid membranes using tributhylphosphate as carrier

    International Nuclear Information System (INIS)

    The facilitated extraction of Cr(VI) through an emulsion liquid membrane (ELM) was investigated, using tributyl phosphate (TBP) as mobile carrier. The emulsion liquid membrane phase consists of kerosene as diluent, TBP as carrier, SPAN 80 as surfactant and (NH4)2CO3 solution as stripping phase. The extraction of chromium (VI) has been studied under various experimental conditions and have been determined the influences of surfactant concentration, extractant concentration, stripping solution base concentration, mixing speed, phase ratio, treatment ratio, chromium (VI) and HCl concentrations of the feed solution. It was observed that the extraction rate of Cr(VI) was affected by changes of surfactant concentration, extractant concentration, stripping solution base concentration, and mixing speed. The results obtained showed that by appropriate selection of the extraction and stability conditions, nearly all of chromium (VI) ions present in the feed solution were extracted within 2-4 min. The separation factors of chromium (VI) with respect to cobalt, nickel, copper, cadmium and zinc ions, based on initial feed concentration, have experimentally determined.

  13. Dynamics of a polymer chain confined in a membrane.

    Science.gov (United States)

    Ramachandran, S; Komura, S; Seki, K; Gompper, G

    2011-05-01

    We present a Brownian dynamics theory with full hydrodynamics (Stokesian dynamics) for a Gaussian polymer chain embedded in a liquid membrane which is surrounded by bulk solvent and walls. The mobility tensors are derived in Fourier space for the two geometries, namely, a free membrane embedded in a bulk fluid, and a membrane sandwiched by the two walls. Within the preaveraging approximation, a new expression for the diffusion coefficient of the polymer is obtained for the free-membrane geometry. We also carry out a Rouse normal mode analysis to obtain the relaxation time and the dynamical structure factor. For large polymer size, both quantities show Zimm-like behavior in the free-membrane case, whereas they are Rouse-like for the sandwiched membrane geometry. We use the scaling argument to discuss the effect of excluded-volume interactions on the polymer relaxation time. PMID:21562968

  14. 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. PMID:26861908

  15. 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.

  16. Active liquid treatment by a combination of precipitation and membrane processes

    International Nuclear Information System (INIS)

    New ultrafiltration processes developed for the treatment of low and medium active radioactive wastes, were applied successfully to a variety of simulated and real wastes, including magnesium alloy clad spent storage fuel pond waters, reprocessing plant solvent wash liquors, plutonium production effluents and mixed site effluents. After initial laboratory scale feasibility experiments the process was scaled up successfully, using a variety of different ultrafiltration modules. The information accumulated on membrane performance, membrane fouling and flux restoration techniques, and ancillary equipment performance was used to design a much larger demonstration pilot plant. This plant has been constructed and is now processing continuously each day over 1m3 of a real radioactive effluent. (author)

  17. Bulk charges in eleven dimensions

    CERN Document Server

    Hawking, Stephen William

    1998-01-01

    Eleven dimensional supergravity has electric type currents arising from the Chern-Simon and anomaly terms in the action. However the bulk charge integrates to zero for asymptotically flat solutions with topological trivial spatial sections. We show that by relaxing the boundary conditions to generalisations of the ALE and ALF boundary conditions in four dimensions one can obtain static solutions with a bulk charge preserving between 1/16 and 1/4 of the supersymmetries. One can introduce membranes with the same sign of charge into these backgrounds. This raises the possibility that these generalized membranes might decay quantum mechanically to leave just a bulk distribution of charge. Alternatively and more probably, a bulk distribution of charge can decay into a collection of singlely charged membranes. Dimensional reductions of these solutions lead to novel representations of extreme black holes in four dimensions with up to four charges. We discuss how the eleven-dimensional Kaluza-Klein monopole wrapped a...

  18. The membranes (Nafion and LDPE) in binary liquid mixtures benzene plus methanol - sorption and swelling

    Czech Academy of Sciences Publication Activity Database

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

    2009-01-01

    Roč. 45, č. 10 (2009), s. 2895-2901. ISSN 0014-3057 R&D Projects: GA ČR GA104/08/0600 Institutional research plan: CEZ:AV0Z40720504 Keywords : membrane * swelling * sorption Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 2.310, year: 2009

  19. INTEGRATION OF FILTRATION AND ADVANCED OXIDATION: DEVELOPMENT OF A MEMBRANE LIQUID-PHASE PLASMA REACTOR

    Science.gov (United States)

    A tiered approach will be undertaken to achieve the overall project goal of demonstrating the integrated membrane/plasma process as an innovative, affordable, sustainable and effective treatment technology for small treatment systems. The team will first use a regimented ap...

  20. Determination of ketamine, norketamine and dehydronorketamine in urine by hollow-fiber liquid-phase microextraction using an essential oil as supported liquid membrane.

    Science.gov (United States)

    Bairros, André Valle de; Lanaro, Rafael; Almeida, Rafael Menck de; Yonamine, Mauricio

    2014-10-01

    Here, we present a method for the determination of ketamine (KT) and its main metabolites, norketamine (NK) and dehydronorketamine (DHNK) in urine samples by using hollow-fiber liquid-phase microextraction (HF-LPME) in the three-phase mode. The fiber pores were filled with eucalyptus essential oil and a solution of 1.0mol/L of HCl was introduced into the lumen of the fiber (acceptor phase). The fiber was submersed in the alkalinized urine containing 10% NaCl, and the system was submitted to lateral shaking (2400rpm) during 30min. Acceptor phase was withdrawn from the fiber, dried and the residue was then derivatized with trifluoroacetic anhydride (TFAA) for further determination by gas chromatography-mass spectrometry (GC-MS). The calibration curves were linear over the specified range and limits of detection (LoDs) obtained for KT, NK and DHNK were below the cut-off value (1.0ng/mL) recommended by the United Nations Office on Drugs and Crime (UNODC). A totally "green chemistry" approach of the sample extraction was obtained by using essential oil as a supported liquid membrane in HF-LPME. The developed method was successfully validated and applied to urine samples collected from two clinical cases in which KT was suspected to be involved. PMID:24810678

  1. 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.

  2. Holdup of O/W emulsion in a packed column for liquid membrane separation of hydrocarbon; Tankasuiso no ekimaku bunri ni okeru jutento nai no emarushon horudo appu

    Energy Technology Data Exchange (ETDEWEB)

    Egashira, R.; Sugimoto, T.; Kawasaki, J. [Tokyo Inst. of Technology, Tokyo (Japan). Faculty of Engineering

    1993-07-10

    Liquid membrane separation of hydrocarbon is an energy saving separation method that is expected of practical use. If the method uses a packed column, the holdup of O/W emulsion affects the effective contact area and residence time of the emulsion. Therefore, this paper describes an attempt to correlate the dynamic emulsion holdup in a packed column in liquid membrane separation of hydrocarbon with property values of the emulsion and external oil phase, and operation variables. The experiment used a mixture of toluene + n - heptane + n - decane for oil phase in the O/W emulsion and saponin aqueous solution for liquid phase (liquid membrane phase). The packed column with an inner diameter of 37 mm used stainless steel McMahon packing. As a result of the experiment, the dynamic emulsion holdup showed a correlation according to the Reynolds number and Galilei number, regardless of whether the emulsion permeates the liquid membrane. The correlation made it possible to estimate in a simple manner the emulsion holdup in the packed column when this separation method is used. 5 refs., 3 figs., 3 tabs.

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

    International Nuclear Information System (INIS)

    Highlights: → Simultaneous separation of tantalum and niobium from the mixture solution. → An extraction through a hollow fiber supported liquid membrane (HFSLM). → The effect on tantalum removal found from Aliquat 336. → The mathematical model focusing on the extraction side of the liquid membrane system was presented. → The mass transfer coefficients of the aqueous feed (ki) and the organic membrane phase (km) for the system were estimated as 1.19 x 10-5 and 1.39 x 10-7 cm/s, respectively. → Experimental data and theoretical values were found to be in good agreement when the concentration of Aliquat336 in the membrane phase was below 4% (v/v). - Abstract: The separation of a mixture of tantalum and niobium in dilute hydrofluoric media via hollow fiber supported liquid membrane (HFSLM) was examined. Quaternary ammonium salt (Aliquat336) diluted in kerosene was used as a carrier. The various effects on the transport and separation of tantalum and niobium were studied: concentration of hydrofluoric acid in the feed solution, concentration of the carrier (Aliquat336) in the membrane phase, types of stripping solutions (NaClO4, thiourea and HCl) and their concentration. The extraction of tantalum in the membrane phase from 0.3 M hydrofluoric acid (HF) by 3% (v/v) Aliquat336 was achieved by leaving niobium in the feed solution. Quantitative recovery of tantalum was achieved by 0.2 M NaClO4. Furthermore, a mathematical model focusing on the extraction side of the liquid membrane system was presented in order to predict the concentration of tantalum at different times. The mass transfer coefficients of the aqueous feed (ki) and the organic membrane phase (km) were estimated as 1.19 x 10-5 and 1.39 x 10-7 cm/s, respectively. Therefore, the mass transfer limiting step is the diffusion of tantalum-Aliquat336 through the liquid membrane. Moreover, mass transfer modeling was performed and the validity of the developed model evaluated. Experimental data and

  4. Equilibrium viscosity of the Zr41.2Ti13.8Cu12.5Ni10Be22.5 bulk metallic glass-forming liquid and viscous flow during relaxation, phase separation, and primary crystallization

    International Nuclear Information System (INIS)

    The flow behavior of the supercooled Zr41.2Ti13.8Cu12.5Ni10Be22.5 bulk metallic glass-forming liquid is studied in isothermal three-point beam-bending experiments. The experiments lead to the determination of the equilibrium viscosity as a function of temperature. Comparison with other glass-forming liquids shows that the Zr41.2Ti13.8Cu12.5Ni10Be22.5, alloy is a strong liquid, similar to sodium silicate liquids. Flow measurements during phase separation and subsequent formation of crystals embedded in a non-crystalline matrix reveal a dramatic slowdown of the kinetics of the matrix that is expressed in an increase of the viscosity by several orders of magnitude

  5. Extraction of Uranium and Cerium mixture with liquid membrane emulsion process using Tributylphosphate extractant

    International Nuclear Information System (INIS)

    As a membrane a mixture of surfactant (span-80), Tributylphosphate in kerosene and sodium carbonate was used. The feeder was a mixture of uranium and cerium solution with 418.88 ppm U and 101.81 ppm Ce concentration in nitrate acid. The variables investigated were % surfactant (1-8 %) percentage, rotary speed for membrane making (2,500-10,000 rpm) and the acidity of feeder (0.5-3 M). The experiment result were that the optimal concentration of surfactant 5 %, rotary speed 7,500 rpm and efficiency extraction (efeks-U = 23.65 %, efeks-Ce = 7.09 %) at 0.5 M nitric acid and the efficiency stripping (efstripp-U = 5.06 %, efstripp-Ce = 99.91 %) at 0.5 M nitric acid

  6. Separation Properties of Supported Ionic Liquid-Polydimethylsiloxane Membrane in Pervaporation Process

    Czech Academy of Sciences Publication Activity Database

    Izák, Pavel; Friess, K.; Hynek, V.; Ruth, W.; Fei, Z.; Dyson, J.P.; Kragl, U.

    2009-01-01

    Roč. 241, 1-3 (2009), s. 182-187. ISSN 0011-9164 Institutional research plan: CEZ:AV0Z40720504 Keywords : ionic liquid * diffusion coefficient * sorption isotherm Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 2.034, year: 2009

  7. Calix[6]arene bearing carboxylic acid and amide groups in polymeric CTA membrane

    International Nuclear Information System (INIS)

    Calix[6]arene having both carboxylic acid (1,3,5-) and carboxamide (2,4,6-) in an alternative way was synthesized. Transport rates of alkali and alkaline-earth metal ions were tested in bulk liquid membrane and polymer inclusion membrane. Ba2+ ion was found to give the highest transport rate among tested metal ions in both BLM and PIM system. In PIM system, high durability (longer than 30 days) of the membrane was observed

  8. EXPERIMENTAL STUDY ON THE GAS-LIQUID FLOW IN THE MEMBRANE MICROPORE AERATION BIOREACTOR

    OpenAIRE

    DONG LIU; ZHENG WANG; MIN-GUAN YANG

    2008-01-01

    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 measur...

  9. Radioactive liquid effluent management - state of art and the role of membrane processes

    International Nuclear Information System (INIS)

    This report reviews the conventional methods involving filtration, chemical precipitation, evaporation and ion exchange, employed for the treatment of low level radioactive effluents. The role of membrane processes, particularly reverse osmosis and ultrafiltration has been assessed with a view to increase the effectiveness of the existing methods. After overviewing the practices followed in major countries, a possible scheme has been proposed. (author). 66 refs., 4 tabs., figs

  10. 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 ...

  11. Evaluation of ultrafiltration membranes for treating low-level radioactive contaminated liquid waste

    International Nuclear Information System (INIS)

    A series of experiments were performed on Waste Disposal Facility (WD) influent using Romicon hollow fiber ultrafiltration modules with molecular weight cutoffs ranging from 2000 to 80,000. The rejection of conductivity was low in most cases. The rejection of radioactivity ranged from 90 to 98%, depending on the membrane type and on the feed concentration. Typical product activity ranged from 7 to 100 dis/min/ml of alpha radiation. Experiments were also performed on alpha-contaminated laundry wastewater. Results ranged from 98 to >99.8%, depending on the membrane type. This yielded a product concentration of less than 0.1 dis/min/ml of alpha radiation. Tests on PP-Building decontamination water yielded rejections of 85 to 88% alpha radiation depending on the membrane type. These experiments show that the ability to remove radioactivity by membrane is a function of the contents of the waste stream because the radioactivity in the wastewater is in various forms: ionic, polymeric, colloidal, and absorbed onto suspended solids. Although removal of suspended or colloidal material is very high, removal of ionic material is not as effective. Alpha-contaminated laundry wastewater proved to be the easiest to decontaminate, whereas the low-level PP-Building decontamination water proved to be the most difficult to decontaminate. Decontamination of the WD influent, a combined waste stream, varied considerably from day to day because of its constantly changing makeup. The WD influent was also treated with various substances, such as polyelectrolytes, complexing agents, and coagulants, to determine if these additives would aid in the removal of radioactive material from the various wastewaters by complexing the ionic species. At the present time, none of the additives evaluated has had much effect; but experiments are continuing

  12. Influence of Ionic Liquid Content on Properties of Dense Polymer Membranes

    Czech Academy of Sciences Publication Activity Database

    Kohoutová, Marie; Sikora, Antonín; Hovorka, Š.; Randová, A.; Schauer, Jan; Tišma, J.; Setničková, Kateřina; Petričkovič, Roman; Guernik, S.; Greenspoon, N.; Izák, Pavel

    2009-01-01

    Roč. 45, č. 3 (2009), s. 813-819. ISSN 0014-3057 R&D Projects: GA ČR GA104/08/0600; GA ČR GA203/08/0465 Grant ostatní: MERG(XE) CT/2006/44737 Institutional research plan: CEZ:AV0Z40720504; CEZ:AV0Z40500505 Keywords : dense polymer membranes * biofuel * fermentation Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 2.310, year: 2009

  13. LINEAR POLYSILOXANE WITH DIBENZO-18-CROWN-6 MOIETIES AS LIQUID MEMBRANE CARRIER

    Institute of Scientific and Technical Information of China (English)

    GONG Shuling; LU Xueran; LU Xianming; CHEN Yuanyin

    1995-01-01

    A modified method of preparing crown functionalized linear polysiloxane has beendescribed. 4'-Allyldibenzo- 18-crown-6 was subjected to hydrosilylation withmethyldichlorosilane, followed by polycondensation with silanol-terminatedpolydimethylsiloxane to give the title crown functionalized linear polysiloxane. Thetransport properties of sodium, potassium, and ammonium salt through a bulk liquidmembrane system using the new type of crown functionalized linear polysiloxane as acarrier were investigated. It is worthy to point out that the carrier can be used repeatedlyat least six runs with no apparent change in the transport rate of potassium ion.

  14. Uranium(VI) extraction from chloride solution with benzyloctadecyldimethyl ammonium chloride (BODMAC) in a liquid membrane process

    International Nuclear Information System (INIS)

    The recovery of uranium(VI) from chloride solution using a liquid emulsion membrane (LEM) technique was studied. The emulsion is constituted by the quaternary salt of benzyloctadecyldimethyl ammonium chloride (BODMAC, R4NCl) as a carrier, kerosene as organic diluent, Span 80 as emulsifying agent and 0.5 mol/l Na2CO3 as stripping phase. The important variables affecting the LEM permeation process such as the concentrations of extractant, internal strip phase, types of organic diluent, and the presence of magnesium chloride or magnesium sulfate were investigated. It was found that, at a given condition, the maximum extraction rate of uranium(VI) reached 80%. The emulsion was stable at low pH in the presence of certain amounts of electrolytes such as NaCl and MgCl2. (author)

  15. 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.

  16. Separation of Am(III) from SHLW using a hollow fiber supported liquid membrane containing TODGA as the carrier

    International Nuclear Information System (INIS)

    Facilitated transport of Am(III) from nitrate medium has been investigated through a hollow fibre supported liquid membrane using N,N,N',N'-tetraoctyl diglycolamide (TODGA) as the carrier. The influence of aqueous feed composition on the permeability of Am(III) is reported. Quantitative transport of Am(III) was observed in 45 min from a feed solution containing 1g/l Nd(III) at 3.5M HNO3. Similarly, quantitative transport of Am(III) was observed in 30 min from a synthetic high level waste containing ∼0.6g/l total lanthanides, in addition to the other non-extractable metal ions. (author)

  17. Actinide partitioning by TODGA hollow fiber supported liquid membrane: a cold test with simulated high level waste

    International Nuclear Information System (INIS)

    Transport behaviour of lanthanides from PHWR-Simulated High Level Waste (SHLW) was investigated using hollow fibre supported liquid membrane (HFSLM) containing 0.1M TODGA (N,N,N',N'-tetraoctyl diglycolamide) + 0.5M DHOA (N,N-dihexyl octanamide) as the carrier. The transport studies were conducted on 20 litres scale as a cold test with PHWR-SHLW. All the lanthanides could be quantitatively transported into the strip phase in 18hrs. None of the other elements were transported except small quantities of Sr and Mo. The system showed reasonably good stability studied up to 72 hrs of continuous operation. The results suggested the possible application of TODGA-HFSLM system for the recovery of minor actinides from high level wastes. (author)

  18. Ultrasensitive determination of cadmium in seawater by hollow fiber supported liquid membrane extraction coupled with graphite furnace atomic absorption spectrometry

    Science.gov (United States)

    Peng, Jin-feng; Liu, Rui; Liu, Jing-fu; He, Bin; Hu, Xia-lin; Jiang, Gui-bin

    2007-05-01

    A new procedure, based on hollow fiber supported liquid membrane preconcentration coupled with graphite furnace atomic absorption spectrometry (GFAAS) detection, was developed for the determination of trace Cd in seawater samples. With 1-octanol that contained a mixture of dithizone (carrier) and oleic acid immobilized in the pores of the polypropylene hollow fiber as a liquid membrane, Cd was selectively extracted from water samples into 0.05 M HNO 3 that filled the lumen of the hollow fiber as a stripping solution. The main extraction related parameters were optimized, and the effects of salinity and some coexisting interferants were also evaluated. Under the optimum extraction conditions, an enrichment factor of 387 was obtained for a 100-mL sample solution. In combination with graphite furnace atomic absorption spectrometry, a very low detection limit (0.8 ng L - 1 ) and a relative standard deviation (2.5% at 50 ng L - 1 level) were achieved. Five seawater samples were analyzed by the proposed method without dilution, with detected Cd concentration in the range of 56.4-264.8 ng L - 1 and the relative spiked recoveries over 89%. For comparison, these samples were also analyzed by the Inductively Coupled Plasma Mass Spectrometry (ICP-MS) method after a 10-fold dilution for matrix effect elimination. Statistical analysis with a one-way ANOVA shows no significant differences (at 0.05 level) between the results obtained by the proposed and ICP-MS methods. Additionally, analysis of certified reference materials (GBW (E) 080040) shows good agreement with the certified value. These results indicate that this present method is very sensitive and reliable, and can effectively eliminate complex matrix interferences in seawater samples.

  19. Ultrasensitive determination of cadmium in seawater by hollow fiber supported liquid membrane extraction coupled with graphite furnace atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Peng Jinfeng; Liu Rui [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P. O. Box 2871, Beijing 100085 (China); Liu Jingfu [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P. O. Box 2871, Beijing 100085 (China)], E-mail: jfliu@rcees.ac.cn; He Bin; Hu Xialin; Jiang Guibin [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P. O. Box 2871, Beijing 100085 (China)

    2007-05-15

    A new procedure, based on hollow fiber supported liquid membrane preconcentration coupled with graphite furnace atomic absorption spectrometry (GFAAS) detection, was developed for the determination of trace Cd in seawater samples. With 1-octanol that contained a mixture of dithizone (carrier) and oleic acid immobilized in the pores of the polypropylene hollow fiber as a liquid membrane, Cd was selectively extracted from water samples into 0.05 M HNO{sub 3} that filled the lumen of the hollow fiber as a stripping solution. The main extraction related parameters were optimized, and the effects of salinity and some coexisting interferants were also evaluated. Under the optimum extraction conditions, an enrichment factor of 387 was obtained for a 100-mL sample solution. In combination with graphite furnace atomic absorption spectrometry, a very low detection limit (0.8 ng L{sup -1}) and a relative standard deviation (2.5% at 50 ng L{sup -1} level) were achieved. Five seawater samples were analyzed by the proposed method without dilution, with detected Cd concentration in the range of 56.4-264.8 ng L{sup -1} and the relative spiked recoveries over 89%. For comparison, these samples were also analyzed by the Inductively Coupled Plasma Mass Spectrometry (ICP-MS) method after a 10-fold dilution for matrix effect elimination. Statistical analysis with a one-way ANOVA shows no significant differences (at 0.05 level) between the results obtained by the proposed and ICP-MS methods. Additionally, analysis of certified reference materials (GBW (E) 080040) shows good agreement with the certified value. These results indicate that this present method is very sensitive and reliable, and can effectively eliminate complex matrix interferences in seawater samples.

  20. Evaluation of progesterone content in saliva using magnetic particle-based immuno supported liquid membrane assay (m-ISLMA).

    Science.gov (United States)

    Tudorache, Madalina; Zdrojewska, Izabela Anna; Emnéus, Jenny

    2006-08-15

    Progesterone in saliva was monitored using a new method called magnetic particle-based immuno supported liquid membrane assay (m-ISLMA) in a sequential injection (SI) setup, allowing automatic sample cleanup, analyte enrichment, and detection in a single analysis unit. Progesterone (Ag) diffuses from a continuous flowing sample - the donor - into a supported organic liquid membrane (SLM), based on analyte partitioning (solubility) between the aqueous donor and the organic phase. The Ag is re-extracted from the SLM into a second stagnant aqueous acceptor, containing antibodies (Ab) immobilized on magnetic beads, held at the bottom of the acceptor by a magnet. Due to the formation of strong Ag-Ab-bead complexes and a large excess of Ab-beads, the Ag is accumulated and selectively enriched in the acceptor. The extracted progesterone was quantified by injecting into the acceptor a horseradish peroxidase (HRP) labeled analyte tracer, the substrate (luminol, H(2)O(2), and p-iodophenol), and finally detection of the generated chemiluminescence by a photomultiplier tube. After optimization of experimental parameters (e.g., sample flow rate, extraction time, type of organic solvent and antibody-bead concentration in the acceptor), a detection limit of 8.50+/-0.17 fgL(-1) and a dynamic range between 35 fgL(-1) and 10 pgL(-1) was reached. The progesterone level of saliva for three subjects (women in different period of ovarian cycle) was investigated, and the corresponding progesterone concentrations detected with m-ISLMA coincided well with the expected values. PMID:16473507

  1. Ultrasensitive determination of cadmium in seawater by hollow fiber supported liquid membrane extraction coupled with graphite furnace atomic absorption spectrometry

    International Nuclear Information System (INIS)

    A new procedure, based on hollow fiber supported liquid membrane preconcentration coupled with graphite furnace atomic absorption spectrometry (GFAAS) detection, was developed for the determination of trace Cd in seawater samples. With 1-octanol that contained a mixture of dithizone (carrier) and oleic acid immobilized in the pores of the polypropylene hollow fiber as a liquid membrane, Cd was selectively extracted from water samples into 0.05 M HNO3 that filled the lumen of the hollow fiber as a stripping solution. The main extraction related parameters were optimized, and the effects of salinity and some coexisting interferants were also evaluated. Under the optimum extraction conditions, an enrichment factor of 387 was obtained for a 100-mL sample solution. In combination with graphite furnace atomic absorption spectrometry, a very low detection limit (0.8 ng L-1) and a relative standard deviation (2.5% at 50 ng L-1 level) were achieved. Five seawater samples were analyzed by the proposed method without dilution, with detected Cd concentration in the range of 56.4-264.8 ng L-1 and the relative spiked recoveries over 89%. For comparison, these samples were also analyzed by the Inductively Coupled Plasma Mass Spectrometry (ICP-MS) method after a 10-fold dilution for matrix effect elimination. Statistical analysis with a one-way ANOVA shows no significant differences (at 0.05 level) between the results obtained by the proposed and ICP-MS methods. Additionally, analysis of certified reference materials (GBW (E) 080040) shows good agreement with the certified value. These results indicate that this present method is very sensitive and reliable, and can effectively eliminate complex matrix interferences in seawater samples

  2. Electro-enhanced hollow fiber membrane liquid phase microextraction of Cr(VI) oxoanions in drinking water samples.

    Science.gov (United States)

    Chanthasakda, Nattaporn; Nitiyanontakit, Sira; Varanusupakul, Pakorn

    2016-02-01

    Hollow fiber membrane liquid phase microextraction (HF-LPME) of metal oxoanions was studied using an ionic carrier enhanced by the application of an electric field (electro-enhanced HF-LPME). The Cr(VI) oxoanion was used as the model. The transportation of Cr(VI) oxoanions across the supported liquid membrane (SLM) was explored via the ion-exchange process and electrokinetic migration. The type of SLM, type of acceptor solution, extraction time, electric potential, and stirring rate were investigated and optimized using MilliQ water. Electro-enhanced HF-LPME provided a much higher enrichment factor compared to conventional HF-LPME (no electric potential) for the same extraction time. A mixture of an anion exchange carrier (methyltrialkyl-ammonium chloride, Aliquat 336) in the SLM facilitated the transportation of Cr(VI) oxoanions. The SLM that gave the best performance was 1-heptanol mixed with 5% Aliquat 336 with 1M NaOH as the acceptor. Linearity was obtained in the working range of 3-15 µg L(-1) Cr(VI) (R(2)>0.99) at 30 V with a 5 min extraction time. The limit of detection was below 5 µg L(-1). The relative standard deviation was less than 12%. The method was applied to drinking water samples. The recoveries of spiked Cr(VI) in drinking water samples were in the range of 96-101% based on the matrix-matched calibration curves. The method was limited to samples containing low levels of ions due to the occurrence of electrolysis. The type of SLM, particularly regarding its resistance, should be tuned to control this problematic phenomenon. PMID:26653501

  3. 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) 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.

  4. Transport of glycosides through liquid organic membranes mediated by reversible boronate formation is a diffusion-controlled process

    Energy Technology Data Exchange (ETDEWEB)

    Morin, G.T.; Hughes, M.P.; Paugam, M.F.; Smith, B.D. (Univ. of Notre Dame, IN (United States))

    1994-10-05

    The ability of phenylboronic acid, [3-(1-adamantylcarboxamido)phenyl]boronic acid, and diphenylborinic acid to extract and transport p-nitrophenyl [beta]-D-glucopyranoside (glucoside), p-nitrophenyl [beta]-D-galactopyranoside (galactoside), and p-nitrophenyl [beta]-D-mannopyranoside (mannoside) through a liquid organic membrane, in the presence of trioctylmethylammonium or tetrabutylammonium chloride, was determined. Under the conditions examined, glycoside transport was facilitated by the reversible formation of covalent tetrahedral, anionic glycoside-boronate complexes, which partitioned into the organic membrane as lipophilic ion pairs. The results of various experiments indicated the rate-limiting step in the transport process was diffusion of the solutes through the narrow unstirred boundary layers adjacent the organic/aqueous interfaces. A plot of glycoside transport rate versus glycoside extraction constant, K[sub ex], formed an approximate bell-shaped relationship. Maximal transport occurred when the carrier admixture had an extraction constant of log K[sub ex(max)] approximately 2.2. 20 refs., 4 figs., 2 tabs.

  5. Combined photocatalysis and membrane bioreactor for the treatment of feedwater containing thin film transistor-liquid crystal display discharge.

    Science.gov (United States)

    You, Sheng-Jie; Semblante, Galilee Uy; Chen, Yu-Pu; Chang, Tien-Chin

    2015-01-01

    The nitrogen content of waste water generated by the thin film transistor-liquid crystal display (TFT-LCD) industry is not satisfactorily removed through the conventional aerobic-activated sludge process. In this study, the performance of three reactors – suspended type TiO2 membrane photoreactor (MPR), anoxic/oxic membrane bioreactor (AOMBR), and their combination (MPR-AOMBR) – was evaluated using feedwater containing TFT-LCD discharge. The parameters that maximized monoethanolamine (MEA) removal in the MPR were continuous ultraviolet (UV) irradiation and pH 11. Among the tested loadings, 0.1 g/l of TiO2 promoted MEA removal but degradation rate may further increase with photocatalyst concentration. The nitrified sludge recycle ratio R of the AOMBR was adjusted to 1.5 to minimize the amount of nitrate in the effluent. The AOMBR greatly decreased chemical oxygen demand and MEA, but removed only 32.7% of tetramethyl ammonium hydroxide (TMAH). The MPR was configured as the pre-treatment unit for AOMBR, and the combined MPR-AOMBR has improved TMAH removal by 80.1%. The MPR bolstered performance by decomposing slowly biodegradable compounds, and had no negative effects on denitrification and carbon removal. PMID:25952015

  6. Removal of non-steroidal anti-inflammatory drugs ibuprofen and ketoprofen from water by emulsion liquid membrane.

    Science.gov (United States)

    Dâas, Attef; Hamdaoui, Oualid

    2014-02-01

    In this work, the removal of the worldwide non-steroidal anti-inflammatory drugs ibuprofen (IBP) and ketoprofen (KTP) by emulsion liquid membrane (ELM) was carried out. An ELM system is made up of hexane as diluent, Span 80 as the surfactant and sodium carbonate as the inner aqueous solution. Effect of experimental conditions that affect the extraction of IBP such as surfactant concentration, emulsification time, sulfuric acid concentration in external phase, acid type in external phase, internal phase concentration, type of internal phase, stirring speed, volume ratio of internal phase to membrane phase, treatment ratio, IBP initial concentration, diluent type and salt was investigated. The obtained results showed that by appropriate selection of the operational parameters, it was possible to extract nearly all of IBP molecules from the feed solution even in the presence of high concentration of salt. Under optimum operating conditions, the efficiencies of IBP removal from distilled water (99.3 %), natural mineral water (97.3 %) and sea water (94.0 %) were comparable, which shows that the ELM treatment process represents a very interesting advanced separation process for the removal of IBP from complex matrices such as natural and sea waters. Under the optimized experimental conditions, approximately 97.4 % KTP was removed in less than 20 min of contact time. PMID:24037298

  7. Modeling efficiency and water balance in PEM fuel cell systems with liquid fuel processing and hydrogen membranes

    Science.gov (United States)

    Pearlman, Joshua B.; Bhargav, Atul; Shields, Eric B.; Jackson, Gregory S.; Hearn, Patrick L.

    Integrating PEM fuel cells effectively with liquid hydrocarbon reforming requires careful system analysis to assess trade-offs associated with H 2 production, purification, and overall water balance. To this end, a model of a PEM fuel cell system integrated with an autothermal reformer for liquid hydrocarbon fuels (modeled as C 12H 23) and with H 2 purification in a water-gas-shift/membrane reactor is developed to do iterative calculations for mass, species, and energy balances at a component and system level. The model evaluates system efficiency with parasitic loads (from compressors, pumps, and cooling fans), system water balance, and component operating temperatures/pressures. Model results for a 5-kW fuel cell generator show that with state-of-the-art PEM fuel cell polarization curves, thermal efficiencies >30% can be achieved when power densities are low enough for operating voltages >0.72 V per cell. Efficiency can be increased by operating the reformer at steam-to-carbon ratios as high as constraints related to stable reactor temperatures allow. Decreasing ambient temperature improves system water balance and increases efficiency through parasitic load reduction. The baseline configuration studied herein sustained water balance for ambient temperatures ≤35 °C at full power and ≤44 °C at half power with efficiencies approaching ∼27 and ∼30%, respectively.

  8. 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. PMID:26753984

  9. Effect of carrier concentration on transportation of thorium from nitric acid medium across supported liquid membrane using Aliquat 336 as carrier

    International Nuclear Information System (INIS)

    Thorium transportation across supported liquid membrane from nitric acid as a function of carrier concentration and feed acidity is studied. Thorium transportation increased with nitric acid concentration till 5 M feed acidity and decreased after wards. Thorium permeability coefficient varies greatly as a function of carrier concentration depending on the feed acidity conditions. (author)

  10. ARSENIC DETERMINATION IN SALINE WATERS UTILIZING A TUBULAR MEMBRANE AS A GAS-LIQUID SEPATRATOR FOR HYDRIDE GENERATION INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY

    Science.gov (United States)

    A tubular silicone rubber membrane is evaluated as a gas-liquid separator for the determination of arsenic in saline waters via HG-ICP-MS. The system was optimized in terms of NaBH and HCI concentrations. The intermediate gas and carrier gas were optimized in terms of sensitiity ...

  11. Effective Permeability of Binary Mixture of Carbon Dioxide and Methane and Pre-Dried Raw Biogas in Supported Ionic Liquid Membranes

    Czech Academy of Sciences Publication Activity Database

    Kárászová, Magda; Sedláková, Zuzana; Friess, K.; Izák, Pavel

    2015-01-01

    Roč. 153, OCT 16 (2015), s. 14-18. ISSN 1383-5866 R&D Projects: GA ČR GA14-12695S; GA MŠk LH14006 Institutional support: RVO:67985858 Keywords : supported ionic liquid membrane * biogas upgrading * real biogas Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 3.091, year: 2014

  12. Sensitivity enhancement in direct coupling of supported liquid membrane extractions to capillary electrophoresis by means of transient isotachophoresis and large electrokinetic injections

    Czech Academy of Sciences Publication Activity Database

    Pantůčková, Pavla; Kubáň, Pavel; Boček, Petr

    2015-01-01

    Roč. 1389, APR (2015), s. 1-7. ISSN 0021-9673 R&D Projects: GA ČR(CZ) GA13-05762S Institutional support: RVO:68081715 Keywords : capillary electrophoresis * in-line coupling * supported liquid membrane extraction Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 4.169, year: 2014

  13. On-line coupling of a clean-up device with supported liquid membrane to capillary electrophoresis for direct injection and analysis of serum and plasma samples

    Czech Academy of Sciences Publication Activity Database

    Kubáň, Pavel; Boček, Petr

    2012-01-01

    Roč. 1234, APR 20 (2012), s. 2-8. ISSN 0021-9673 R&D Projects: GA ČR GAP206/10/1219 Institutional research plan: CEZ:AV0Z40310501 Keywords : capillary electrophoresis * on-line sample treatment * supported liquid membranes Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 4.612, year: 2012

  14. Active liquid treatment by a combination of precipitation and membrane processes

    International Nuclear Information System (INIS)

    Ultrafiltration-based processes have been developed for the treatment of low and medium-active radioactive wastes. Actinides such as U, Pu and Am were found to be present as insoluble species in many effluents and were separated with high efficiency, by direct ultrafiltration. Soluble nuclides, including complexed actinides, Sr and Cs, were removed at > 99 % efficiency by combined processes, in which very low concentrations (3) of ultrafine activity absorbing precipitates were added. The new ultrafiltration processes were applied successfully to a variety of simulated and real wastes, including magnesium alloy clad spent storage fuel pond waters, reprocessing plant solvent wash liquors, plutonium production effluents and mixed site effluents. After initial laboratory scale feasibility experiments, the process was scaled up, using a variety of different ultrafiltration modules. An inorganic, tubular ultrafiltration module was selected for more detailed investigation and an automated mini-unit was constructed for longterm evaluation. The information thus accumulated on membrane performance, membrane fouling and flux restoration techniques, and ancillary equipment performance was used to design a much larger demonstration pilot plant. This plant is now processing continuously each day over 1 m3 of a real radioactive effluent

  15. 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

  16. Magnetic Modulation of the Transport of Organophilic Solutes through Supported Magnetic Ionic Liquid Membranes.

    Czech Academy of Sciences Publication Activity Database

    Daniel, C.L.; Rubio, A.M.; Sebastião, P.J.; Afonso, C.A.M.; Storch, Jan; Izák, Pavel; Portugal, C.A.M.; Crespo, J.G.

    2016-01-01

    Roč. 505, MAY 1 (2016), s. 36-43. ISSN 0376-7388 R&D Projects: GA ČR(CZ) GAP106/12/0569 Grant ostatní: ERANET(PT) ERA-CHEM/0001/2008; EUI(ES) 2008- 03857; FCT-MCTES(PT) SFRH/BD/81552/2011 Institutional support: RVO:67985858 Keywords : magnetic ionic liquids (MILs) * solute transport modulation * magnetic field Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 5.056, year: 2014

  17. Organic Vapour Sorption and Permeation in Polymer Gel Membrane Containing Imidazolium Based Ionic Liquid

    Czech Academy of Sciences Publication Activity Database

    Morávková, Lenka; Vopička, O.; Vejražka, Jiří; Vychodilová, Hana; Sedláková, Zuzana; Friess, K.; Izák, Pavel

    Prague : Orgit, 2014, s. 75. ISBN 978-80-02-02555-9. [International Congress of Chemical and Process Engineering /21./ - CHISA 2014 and Conference on Process Integration, Modelling and Optimisation for Energy Saving and Pollution Reduction /17./ - PRES 2014. Prague (CZ), 23.08.2014-27.08.2014] R&D Projects: GA ČR GA14-12695S; GA TA ČR TE01020080; GA MŠk(CZ) LD13018 Institutional support: RVO:67985858 Keywords : volatile organic compound * acetone * ionic liquids Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  18. Organic Vapour Sorption and Permeation in Polymer Gel Membrane Containing Imidazolium Based Ionic Liquid

    Czech Academy of Sciences Publication Activity Database

    Morávková, Lenka; Vopička, O.; Vejražka, Jiří; Vychodilová, Hana; Sedláková, Zuzana; Friess, K.; Izák, Pavel

    Prague: Orgit, 2014, s. 75. ISBN 978-80-02-02555-9. [International Congress of Chemical and Process Engineering /21./ - CHISA 2014 and Conference on Process Integration, Modelling and Optimisation for Energy Saving and Pollution Reduction /17./ - PRES 2014. Prague (CZ), 23.08.2014-27.08.2014] R&D Projects: GA ČR GA14-12695S; GA TA ČR TE01020080; GA MŠk(CZ) LD13018 Institutional support: RVO:67985858 Keywords : volatile organic compound * acetone * ionic liquids Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  19. Anaerobic membrane bioreactors and the influence of space velocity and biomass concentration on methane production for liquid dairy manure

    International Nuclear Information System (INIS)

    Two pilot-scale anaerobic membrane bioreactors (AnMBRs) and a control completely mixed digester (CMD) were constructed to evaluate the influence of space velocity and biomass concentration on methane production for sand separated dairy manure. A negative impact on methane production resulted with operating the AnMBR system at 972 μHz–2960 μHz but no impact was found when operating at 69 μHz and 312 μHz. Operating at 69 μHz–350 μHz is realistic for a field installation. Despite the higher biomass concentration, the methane production of the AnMBRs was nearly equal to the CMD. An AnMBR with 69 μHz was operated equivalent to a CMD by returning all permeate to the digester tank and removing excess biomass directly from the reactor tank resulting in a hydraulic retention time (HRT) equal to the solids retention time (SRT). When using sand separated dairy manure and an HRT (and equal SRT) of 12 d, both systems produced methane at an equal rate, suggesting that the pump/membrane system did not influence methane production. The most likely reason was mass transfer limitations of hydrolytic enzymes. Based on methane production and volatile fatty acids analysis, it appears the fermentable substrate available for degradation was similar. The AnMBR proved to have benefit as part of an integrated nutrient management system that produced water that is virtually free of particulate nutrients, especially phosphorus. This enables the irrigation of the water to crops that need nitrogen and the efficient movement of phosphorus, as a solid, to needed locations. - Highlights: • Manure AnMBRs with a high space velocity inhibit methane production. • Manure AnMBRs with a low space velocity perform similar to conventional digesters. • Decoupled HRT and SRT in manure AnMBRs do not increase methane production. • Ultrafiltration membranes effectively partitioned manure nutrients from the liquid. • Manure does not foul ultrafiltration membranes and require mild

  20. Selective decontamination of cesium and strontium from evaporation concentrates of spent fuel reprocessing plants with crown ethers by transport through supported liquid membranes

    International Nuclear Information System (INIS)

    Reprocessing operations lead to the production of radioactive medium activity liquid waste which is treated by evaporation and solutions of very high salinity are thus formed. The concentrates from reprocessing plant evaporators have to be stored in geological storage sites in view of their strong caesium, strontium and actinides activity. These elements, contained in acid and high sodium nitrate content liquid waste, are removed by means of selective extractants, using the supported liquid membrane technique (SLM), which allows them to be stored in surface sites, the actinides and long-life fission products being respectively recycled and concentrated into reduced volumes. The removal of the actinides is done by means of an Octyl N.N Diisobutyl Carbamoyl Methyl Phosphine Oxide (C.M.P.O.) based liquid membrane, whereas the removal of the caesium and strontium involves crown ethers. Supported liquid membranes (S.L.M.s) have the advantage of implementing very small quantities of extractant, but they generally have poor stability. The extractant, the diluent and the phase modifier impregnating the membrane play a vital role in SLM stability; the support also affects stability by its nature and geometry. For the extraction of strontium, the most lipophilic extractant, DtBu 18 C 6, enables higher strontium transfer kinetics to be attained. As regards caesium, the extremely lipophilic nDec B21 C7 is the most efficient. Caesium cannot be quantitatively removed, due to the competition of the very high content of sodium ions in the concentrate. Stable membranes are obtained with DC18 C6 or DtBu18 C6 diluted in alkylbenzenes with an added phase modifier such as decanol or especially isotridecanol

  1. Selective decontamination for cesium and strontium in evaporation concentrates from reprocessing plants with crown ethers by transport through supported liquid membranes

    International Nuclear Information System (INIS)

    Reprocessing operations lead to the production of radioactive medium activity liquid waste which is treated by evaporation. The concentrates from reprocessing plant evaporators have to be stored in geological storage sites in view of their strong caesium, strontium and actinides activity. These elements, contained in acid and high sodium nitrate content liquid waste, are removed by means of selective extractants, using the supported liquid membrane technique (SLM), which allows them to be stored in surface sites, the actinides and long-life fission products being respectively recycled and concentrated into reduced volumes. The removal of the actinides is done by means of an Octyl N.N Diisobutyl Carbamoyl Methyl Phosphine Oxyde (C.M.P.O.) based liquid membrane, whereas the removal of the caesium and strontium involves crown ethers. Supported liquid membranes (S.L.M.s) have the advantage of implementing very small quantities of extractant, but, they generally have poor stability. The extractant, the diluent and the phase modifier that constitute the organic phase impregnating the membrane play a vital role in SLM stability; the support also affects stability by its nature and geometry. For the extraction of strontium, DtBu 18 C6 enables higher strontium transfer kinetics to be attained than with DC18 C6. As regards caesium, nDec B21 C7 is the most efficient. Unlike strontium, caesium cannot be quantitatively removed, due to the competition of sodium ions in the concentrate. Stable membranes are obtained with DC18 C6 or DtBu18 C6 diluted in alkylbenzene with an added phase modifier such as decanol or isotridecanol. The highest strontium transfer kinetics were obtained with the DC18 C6/hexylbenzene/isotridecanol mixture

  2. Liquid state DNP for water accessibility measurements on spin-labeled membrane proteins at physiological temperatures

    Science.gov (United States)

    Doll, Andrin; Bordignon, Enrica; Joseph, Benesh; Tschaggelar, René; Jeschke, Gunnar

    2012-09-01

    We demonstrate the application of continuous wave dynamic nuclear polarization (DNP) at 0.35 T for site-specific water accessibility studies on spin-labeled membrane proteins at concentrations in the 10-100 μM range. The DNP effects at such low concentrations are weak and the experimentally achievable dynamic nuclear polarizations can be below the equilibrium polarization. This sensitivity problem is solved with an optimized home-built DNP probe head consisting of a dielectric microwave resonator and a saddle coil as close as possible to the sample. The performance of the probe head is demonstrated with both a modified pulsed EPR spectrometer and a dedicated CW EPR spectrometer equipped with a commercial NMR console. In comparison to a commercial pulsed ENDOR resonator, the home-built resonator has an FID detection sensitivity improvement of 2.15 and an electron spin excitation field improvement of 1.2. The reproducibility of the DNP results is tested on the water soluble maltose binding protein MalE of the ABC maltose importer, where we determine a net standard deviation of 9% in the primary DNP data in the concentration range between 10 and 100 μM. DNP parameters are measured in a spin-labeled membrane protein, namely the vitamin B12 importer BtuCD in both detergent-solubilized and reconstituted states. The data obtained in different nucleotide states in the presence and absence of binding protein BtuF reveal the applicability of this technique to qualitatively extract water accessibility changes between different conformations by the ratio of primary DNP parameters ɛ. The ɛ-ratio unveils the physiologically relevant transmembrane communication in the transporter in terms of changes in water accessibility at the cytoplasmic gate of the protein induced by both BtuF binding at the periplasmic region of the transporter and ATP binding at the cytoplasmic nucleotide binding domains.

  3. Bulk undercooling

    Science.gov (United States)

    Kattamis, T. Z.

    1984-01-01

    Bulk undercooling methods and procedures will first be reviewed. Measurement of various parameters which are necessary to understand the solidification mechanism during and after recalescence will be discussed. During recalescence of levitated, glass-encased large droplets (5 to 8 mm diam) high speed temperature sensing devices coupled with a rapid response oscilloscope are now being used at MIT to measure local thermal behavior in hypoeutectic and eutectic binary Ni-Sn alloys. Dendrite tip velocities were measured by various investigators using thermal sensors or high speed cinematography. The confirmation of the validity of solidification models of bulk-undercooled melts is made difficult by the fineness of the final microstructure, the ultra-rapid evolution of the solidifying system which makes measurements very awkward, and the continuous modification of the microstructure which formed during recalescence because of precipitation, remelting and rapid coarsening.

  4. Design and Construction of Control System for Extracting Uranium byContinuous Liquid Emulsion Membrane

    International Nuclear Information System (INIS)

    The interface of computer based process control for uranium separationhas been designed and constructed. The system function is for controlling thetemperature, stirring velocity and pump flow of extraction process. Theinterface card consist of temperature transducer, voltage amplifier, 12 bitADC system, address decode, peripheral Parallel Interface D8255C-2, currentamplifier and motor stepper. The testing on water temperature measurementwith flow rate of 10 ml/sec at the process temperature of 72 oC and 80 oCare 72.89 oC and 81.25 oC respectively. The testing made to the ADC andamplifier systems shows good performance of the expected values, withlinearity is 0.999. At the stirring velocity of 400 rpm the efficiency ofcontinuous extraction system is 66.89 %. By the control system theperformance of uranium extraction process by continuous liquid emulsionmembrane can be enhanced. (author)

  5. 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.

  6. 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.

  7. Double-phase liquid membrane extraction for the analysis of pesticides

    International Nuclear Information System (INIS)

    A simple and solvent minimized sample preparation technique based on two-phase hollow fiber-protected liquid-phase micro extraction was investigated for HPLC analysis of selected pesticides in water samples. Four pesticides (procymidon, methidathion, quinalphos, and vinclozolin) were considered as target analysts. Parameters such as extraction solvent, salt concentration, stirring speed, extraction time, and pH value were optimized using spiked deionised water samples. The analysts were extracted from 12 mL water samples through organic solvent (n-hexane and isooctane) immobilized in the pores of a porous polypropylene hollow fiber into 50 μL acceptor phase present inside the hollow fiber. Excellent separations of analytes were obtained on C18 column using acetonitrile-water ratio of 55:45 v/v at elevated flow rate of 0.8 mL/ min. (author)

  8. 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.

  9. Integrated test plan for the field demonstration of the supported liquid membrane unit

    International Nuclear Information System (INIS)

    This Integrated Test Plan describes the operation and testing of a hybrid reverse osmosis (RO)/coupled transport (CT) groundwater remediation test unit, also referred to as the Environmental Restoration Technology Demonstrations at the Hanford Site. The SLM will be used to remove uranium, technetium-99, and nitrate from a selected groundwater source at the Hanford Site. The overall purpose of this test is to determine the efficiency of the RO/CT membranes operating in a hybrid unit, the ease of operating and maintaining the SLM, and the amount of secondary waste generated as a result of processing. The goal of the SLM is to develop a RO/CT process that will be applicable for removing contaminants from almost any contaminated water. This includes the effluents generated as part of the day-to-day operation of most any US Department of Energy (DOE) site. The removal of contaminants from the groundwaters before they reach the Columbia River or offsite extraction wells will reduce the risk that the population will be exposed to these compounds and will reduce the cost of subsequent groundwater cleanup

  10. Separation of polyunsaturated fatty acid esters by flowing liquid membrane with porous partition.; Kakumaku gata ryudo ekimaku ni yoru kodo fuhowa shibosan esuteru no bunri

    Energy Technology Data Exchange (ETDEWEB)

    Yokosawa, R.; Nii, S.; Takahashi, K. [Nagoya Univ., Nagoya (Japan). Depertment of Chemical Engineering; Misawa, Y. [Harima Chemicals, Inc., Osaka (Japan)

    2000-07-10

    A laboratory-constructed flowing liquid membrane apparatus with porous partition (FLM) was applied to the separation of such polyunsaturated fatty acid esters (PUFA-Ets) as eicosapentaenoic acid ethylester (EPA-Et) and docosahexaenoic acid ethylester (DHA-Et) at 293 K. The hydrophilic porous membrane was used as a partition, and 2 M AgNO{sub 3} aqueous solution was used as a membrane liquid. By using dodecane as a feed diluent and m-xylene as a recovery solution, PUFA-Ets were successfully separated from mixture of fatty acid esters. The recovery fraction of PUFA-Ets and the separation degree between DHA-Et and EPA-Et were investigated ; it increases with the velocity of membrane liquid and the flow path length in the module, while it decreased with the velocity of feed and recovery solution. The recovery fraction of DHA-Et reachs 60% with only 8 s-retention time by the continuous operation. The concentrations of the DHA-Et at the outlet of the module were simulated based on the mass transfer model, which gave nearly 85% recovery fraction with 30 s-retention time. These results show that a stable operation, a high recovery and a high recovery and a high throughput are realized by the FLM. (author)

  11. 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.

  12. Modeling and simulations of polymer electrolyte membrane fuel cells with poroelastic approach for coupled liquid water transport and deformation in the membrane

    OpenAIRE

    Yeşilyurt, Serhat; Yesilyurt, Serhat

    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...

  13. Comparison of two treatments for the removal of selected organic micropollutants and bulk organic matter: conventional activated sludge followed by ultrafiltration versus membrane bioreactor.

    Science.gov (United States)

    Sahar, E; Ernst, M; Godehardt, M; Hein, A; Herr, J; Kazner, C; Melin, T; Cikurel, H; Aharoni, A; Messalem, R; Brenner, A; Jekel, M

    2011-01-01

    The potential of membrane bioreactor (MBR) systems to remove organic micropollutants was investigated at different scales, operational conditions, and locations. The effluent quality of the MBR system was compared with that of a plant combining conventional activated sludge (CAS) followed by ultrafiltration (UF). The MBR and CAS-UF systems were operated and tested in parallel. An MBR pilot plant in Israel was operated for over a year at a mixed liquor suspended solids (MLSS) range of 2.8-10.6 g/L. The MBR achieved removal rates comparable to those of a CAS-UF plant at the Tel-Aviv wastewater treatment plant (WWTP) for macrolide antibiotics such as roxythromycin, clarithromycin, and erythromycin and slightly higher removal rates than the CAS-UF for sulfonamides. A laboratory scale MBR unit in Berlin - at an MLSS of 6-9 g/L - showed better removal rates for macrolide antibiotics, trimethoprim, and 5-tolyltriazole compared to the CAS process of the Ruhleben sewage treatment plant (STP) in Berlin when both were fed with identical quality raw wastewater. The Berlin CAS exhibited significantly better benzotriazole removal and slightly better sulfamethoxazole and 4-tolyltriazole removal than its MBR counterpart. Pilot MBR tests (MLSS of 12 g/L) in Aachen, Germany, showed that operating flux significantly affected the resulting membrane fouling rate, but the removal rates of dissolved organic matter and of bisphenol A were not affected. PMID:21330721

  14. Simulation of non-linear flow density in transition state from the mathematical model of the diffusion of metal anions through a flat sheet supported liquid membrane

    OpenAIRE

    Benzal, Ma. Graciela; Kumar, Aditya; Sastre Requena, Ana María; Delshams Valdés, Amadeu

    2003-01-01

    A mathematical model is developed for the carrier facilitated transport of metal ions through a flat sheet support liquid membrane (FSSLM) in transition state from Fick’s second law. From this model, and from Fick’s first law, the flow density is derived as a non-linear concentration gradient. Both expressions, concentration and flow density, depend on the thickness of the membrane and on time. Since the rate constant plays an important role in the model, it is considered as th...

  15. Fabrication, Validation, and Performance Evaluation of a New Sampling System for the In-Situ Chemical Speciation of Chromium Ions in Groundwater Using Supported Liquid Membranes (SLMs)

    OpenAIRE

    Owens, Lesley Shantell

    2013-01-01

    A sampler has been fabricated to facilitate the in-situ speciation of Cr. Teflon® was selected as the material for the samplers because of its inert chemical nature. The design of the sampler is based on the Supported Liquid Membrane (SLM) extraction technique, which utilizes charged organic carrier molecules loaded onto a polymeric (Teflon®) support membrane and the principles of electrostatics to selectively transport Cr ions through an ion-pairing mechanism. Cr ions in the feed solution th...

  16. Ferromagnetic bulk glassy alloys

    International Nuclear Information System (INIS)

    This paper deals with the review on the formation, thermal stability and magnetic properties of the Fe-based bulk glassy alloys in as-cast bulk and melt-spun ribbon forms. A large supercooled liquid region over 50 K before crystallization was obtained in Fe-(Al, Ga)-(P, C, B, Si), Fe-(Cr, Mo, Nb)-(Al, Ga)-(P, C, B) and (Fe, Co, Ni)-Zr-M-B (M=Ti, Hf, V, Nb, Ta, Cr, Mo and W) systems and bulk glassy alloys were produced in a thickness range below 2 mm for the Fe-(Al, Ga)-(P, C, B, Si) system and 6 mm for the Fe-Co-(Zr, Nb, Ta)-(Mo, W)-B system by copper-mold casting. The ring-shaped glassy Fe-(Al, Ga)-(P, C, B, Si) alloys exhibit much better soft magnetic properties as compared with the ring-shaped alloy made from the melt-spun ribbon because of the formation of the unique domain structure. The good combination of high glass-forming ability and good soft magnetic properties indicates the possibility of future development as a new bulk glassy magnetic material

  17. Pore Network Modeling and Synchrotron Imaging of Liquid Water in the Gas Diffusion Layer of Polymer Electrolyte Membrane Fuel Cells

    Science.gov (United States)

    Hinebaugh, James Thomas

    Polymer electrolyte membrane (PEM) fuel cells operate at levels of high humidity, leading to condensation throughout the cell components. The porous gas diffusion layer (GDL) must not become over-saturated with liquid water, due to its responsibility in providing diffusion pathways to and from the embedded catalyst sites. Due to the opaque and microscale nature of the GDL, a current challenge of the fuel cell industry is to identify the characteristics that make the GDL more or less robust against flooding. Modeling the system as a pore network is an attractive investigative strategy; however, for flooding simulations to provide meaningful material comparisons, accurate GDL topology and condensation distributions must be provided. The focus of this research is to provide the foundational tools with which to capture both of these requirements. The method of pore network modeling on topologically representative pore networks is demonstrated to describe flooding phenomena within GDL materials. A stochastic modeling algorithm is then developed to create pore spaces with the relevant features of GDL materials. Then, synchrotron based X-ray visualization experiments are developed and conducted to provide insight into condensation conditions. It was found that through-plane porosity distributions have significant effects on the GDL saturation levels. Some GDL manufacturing processes result in high porosity regions which are predicted to become heavily saturated with water if they are positioned between the condensation sites and the exhaust channels. Additionally, it was found that fiber diameter and the volume fraction of binding material applied to the GDL have significant impacts on the GDL heterogeneity and pore size distribution. Representative stochastic models must accurately describe these three material characteristics. In situ, dynamic liquid water behavior was visualized at the Canadian Light source, Inc. synchrotron using imaging and image processing

  18. 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. PMID:22352958

  19. Direct uranium extraction from dihydrate and hemi-dihydrate wet process phosphoric acids by liquid emulsion membrane

    International Nuclear Information System (INIS)

    A new liquid emulsion membrane (LEM) process for uranium extraction from either dihydrate 28-30% P2O5 (DH) or hemi-dihydrate 42-45% P2O5 (HDH) wet process phosphoric acid is proposed. In this process, the organic component of the LEM is composed of a synergistic mixture of 0.1M di-2-ethyl hexyl phosphoric acid (DEHPA) and 0.025M trioctyl phosphine oxide (TOPO) with 4% Span 80. The internal or the strip acid phase is composed of 0.5M citric acid. The prepared LEM was proved to be stable in 42-45% P2O5 acid concentration range and can, therefore, be applied to the phosphoric acid produced by the hemi-dihydrate process. After breakdown of the loaded emulsion, the uranyl citrate in the internal strip phase is separated by adding methanol followed by its calcination to the orange oxide. Most of the reagents used are recycled. The proposed process is characterized by simplicity, practically closed operation cycle in addition to lower capital and operating costs. (author)

  20. 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 ...