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Sample records for high-flashpoint organic liquid

  1. Occupational exposures to new dry cleaning solvents: High-flashpoint hydrocarbons and butylal

    PubMed Central

    Ceballos, Diana M.; Whittaker, Stephen G.; Lee, Eun Gyung; Roberts, Jennifer; Streicher, Robert; Nourian, Fariba; Gong, Wei; Broadwater, Kendra

    2017-01-01

    The dry cleaning industry is moving away from using perchloroethylene. Occupational exposures to two alternative dry cleaning solvents, butylal and high-flashpoint hydrocarbons, have not been well characterized. We evaluated four dry cleaning shops that used these alternative solvents. The shops were staffed by Korean- and Cantonese-speaking owners, and Korean-, Cantonese-, and Spanish-speaking employees. Because most workers had limited English proficiency we used language services in our evaluations. In two shops we collected personal and area air samples for butylal. We also collected air samples for formaldehyde and butanol, potential hydrolysis products of butylal. Because there are no occupational exposure limits for butylal, we assessed employee health risks using control banding tools. In the remaining two shops we collected personal and area air samples for high-flashpoint hydrocarbon solvents. In all shops the highest personal airborne exposures occurred when workers loaded and unloaded the dry cleaning machines and pressed dry cleaned fabrics. The air concentrations of formaldehyde and butanol in the butylal shops were well below occupational exposure limits. Likewise, the air concentrations of high-flashpoint hydrocarbons were also well below occupational exposure limits. However, we saw potential skin exposures to these chemicals. We provided recommendations on appropriate work practices and the selection and use of personal protective equipment. These recommendations were consistent with those derived using control banding tools for butylal. However, there is insufficient toxicological and health information to determine the safety of butylal in occupational settings. Independent evaluation of the toxicological properties of these alternative dry cleaning solvents, especially butylal, is urgently needed. PMID:27105306

  2. Occupational exposures to new dry cleaning solvents: High-flashpoint hydrocarbons and butylal.

    PubMed

    Ceballos, Diana M; Whittaker, Stephen G; Lee, Eun Gyung; Roberts, Jennifer; Streicher, Robert; Nourian, Fariba; Gong, Wei; Broadwater, Kendra

    2016-10-02

    The dry cleaning industry is moving away from using perchloroethylene. Occupational exposures to two alternative dry cleaning solvents, butylal and high-flashpoint hydrocarbons, have not been well characterized. We evaluated four dry cleaning shops that used these alternative solvents. The shops were staffed by Korean- and Cantonese-speaking owners, and Korean-, Cantonese-, and Spanish-speaking employees. Because most workers had limited English proficiency we used language services in our evaluations. In two shops we collected personal and area air samples for butylal. We also collected air samples for formaldehyde and butanol, potential hydrolysis products of butylal. Because there are no occupational exposure limits for butylal, we assessed employee health risks using control banding tools. In the remaining two shops we collected personal and area air samples for high-flashpoint hydrocarbon solvents. In all shops the highest personal airborne exposures occurred when workers loaded and unloaded the dry cleaning machines and pressed dry cleaned fabrics. The air concentrations of formaldehyde and butanol in the butylal shops were well below occupational exposure limits. Likewise, the air concentrations of high-flashpoint hydrocarbons were also well below occupational exposure limits. However, we saw potential skin exposures to these chemicals. We provided recommendations on appropriate work practices and the selection and use of personal protective equipment. These recommendations were consistent with those derived using control banding tools for butylal. However, there is insufficient toxicological and health information to determine the safety of butylal in occupational settings. Independent evaluation of the toxicological properties of these alternative dry cleaning solvents, especially butylal, is urgently needed.

  3. Nonlinear ultrasonic nature of organic liquid and organic liquid mixture.

    PubMed

    Lu, Yi-gang; Zhang, Yang; Dong, Yan-wu

    2006-12-22

    Based on Jacobson's molecular free length theory in liquids and the relationship between ultrasonic velocity and the molecular free length in organic liquids, this paper deduces the equations for pressure coefficient and temperature coefficient of ultrasonic velocity and nonlinear acoustic parameter B/A in both of organic liquid and organic liquid binary mixtures. These nonlinear acoustic parameters are evaluated against the measured results and data from other sources. The equations reveal the connections between the nonlinear acoustic parameters and some internal structural of the medium or mixtures e.g. the sizes of molecule, several thermodynamic physical parameters and outside status e.g. condition of pressure and temperature of the liquid or liquid mixture. With the equations the nonlinear acoustic parameter B/A of organic liquid binary mixtures, which is impossible to know without the nonlinear acoustic parameter B/A of the tow components before, can be calculated based on the structural and physical parameters of organic liquid and organic liquid binary mixtures.

  4. Liquid Crystals for Organic Photovoltaics

    NASA Astrophysics Data System (ADS)

    O'Neill, Mary; Kelly, Stephen M.

    As discussed in Chaps. 2 (10.1007/978-90-481-2873-0_2), 3 (10.1007/978-90-481-2873-3), 5 (10.1007/978-90-481-2873-5) and 6 (10.1007/978-90-481-2873-6), columnar, smectic and, more recently, nematic liquid crystals are widely recognized as very promising charge-transporting organic semiconductors due to their ability to spontaneously self-assemble into highly ordered domains in uniform thin films over large areas. This and their broad absorption spectra make them suitable as active materials for organic photovoltaic devices. In this chapter, we discuss the use of liquid crystals in such devices. Firstly, we examine the principle of power generation via the photovoltaic effect in organic materials and the various device configurations that can optimise efficiency. Then we discuss photovoltaic devices incorporating columnar liquid crystals combined with electron accepting materials based on either perylene or fullerene. The use of nematic and sanditic liquid crystals in photovoltaics is investigated as well as a novel solar cell concentrator incorporating liquid crystals. Finally, we analyse the benefits and limitations of liquid-crystal-based photovoltaics in the context of the state-of-the-art for organics photovoltaics.

  5. Mesoscopic organization in ionic liquids.

    PubMed

    Russina, Olga; Lo Celso, Fabrizio; Plechkova, Natalia; Jafta, Charl J; Appetecchi, Giovanni Battista; Triolo, Alessandro

    2017-06-01

    We discuss some published results and provide new observations concerning the high level of structural complexity that lies behind the nanoscale correlations in ionic liquids (ILs) and their mixtures with molecular liquids. It turns out that this organization is a consequence of the hierarchical construction on both spatial (from ångström to several nanometer) and temporal (from fraction of picosecond to hundreds of nanosecond) scales, which requires joint use of experimental and computational tools.

  6. Separation of organic liquids

    SciTech Connect

    Pasternak, M.; Bartels, C.R.; Reale, J. Jr.

    1989-01-17

    The method is described comprising: concentrating a charge solution containing methanol and either dimethyl carbonate or methyl t-butyl ether oxygenate by, maintaining a membrane of non-porous separating layer of cast polyvinyl alcohol which has been crosslinked with an aliphatic polyaldehyde containing at least three carbon atoms including those in the aldehyde groups; maintaining a pressure drop across the non-porous separating layer of polyvinyl alcohol; passing a charge aqueous solution containing methanol and either dimethyl carbonate or methyl t-butyl ether oxygenate into contact with the high pressure side of the non-porous separating layer of polyvinyl alcohol having properties which enable at least a portion of the methanol in the charge solution and a lesser portion of oxygenate to pass by pervaporation through the non-porous separating layer of polyvinyl alcohol as a lean mixture containing more methanol and less oxygenate than are present in the charge solution and the charge solution is converted to a rich liquid containing less methanol and more oxygenate than are present in the charge solution; recovering as permeate from the low pressure side of the non-porous separating layer of polyvinyl alcohol the lean mixture containing more methanol and less oxygenate than are present in the charge solution, the lean mixture being recovered in vapor phase at a pressure below the vapor pressure thereof; and recovering as retentate from the high pressure side of the non-porous separating layer the rich liquid containing a lower methanol content and a higher oxygenate content than are present in the charge solution.

  7. REMOVAL OF URANIUM FROM ORGANIC LIQUIDS

    DOEpatents

    Vavalides, S.P.

    1959-08-25

    A process is described for recovering small quantities of uranium from organic liquids such as hydrocarbon oils. halogen-substituted hydrocarbons, and alcohols. The organic liquid is contacted with a comminuted alkaline earth hydroxide, calcium hydroxide particularly, and the resulting uranium-bearing solid is separated from the liquid by filtration. Uranium may then be recovered from the solid by means of dissolution in nitric acid and conventional extraction with an organic solvent such as tributyl phosphate.

  8. Liquid crystals for organic transistors (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Hanna, Jun-ichi; Iino, Hiroaki

    2016-09-01

    Liquid crystals are a new type of organic semiconductors exhibiting molecular orientation in self-organizing manner, and have high potential for device applications. In fact, various device applications have been proposed so far, including photosensors, solar cells, light emitting diodes, field effect transistors, and so on.. However, device performance in those fabricated with liquid crystals is less than those of devices fabricated with conventional materials in spite of unique features of liquid crystals. Here we discuss how we can utilize the liquid crystallinity in organic transistors and how we can overcome conventional non-liquid crystalline organic transistor materials. Then, we demonstrate high performance organic transistors fabricated with a smectic E liquid crystal of Ph-BTBT-10, which show high mobility of over 10cm2/Vs and high thermal durability of over 200oC in OFETs fabricated with its spin-coated polycrystalline thin films.

  9. Organic liquid mobility induced by smoldering remediation.

    PubMed

    Kinsman, L; Torero, J L; Gerhard, J I

    2017-03-05

    Laboratory column experiments plus analytical and numerical modeling together suggest that, under certain conditions, downward organic liquid mobilization can occur and impact smoldering behavior. This applies for organic liquids mixed with inert sand subjected to smoldering as thermal treatment. The observed effects include increased peak temperatures (here by up to 35%) and increased treatment times (here by up to 30%). Downward organic liquid migration occurs when (i) injected Darcy air flux is less than a threshold value (here less than 3cm/s), (ii) treatment systems are tall (here 90cm, not 30cm), and (iii) the organic liquid is temperature-sensitive (viscosity less than 0.01Pas at 150°C). The developed analytical equation provides the applied air flux that can negate the downwards organic liquid gradient required for migration. Smoldering behavior is demonstrated to adjust to liquid migration and thereby still destroy all the organic waste in the system. Smoldering is a relatively new, energy-efficient thermal treatment for organic liquid waste and these results are important for designing field applications of smoldering treatment.

  10. Nanoparticles in ionic liquids: interactions and organization.

    PubMed

    He, Zhiqi; Alexandridis, Paschalis

    2015-07-28

    Ionic liquids (ILs), defined as low-melting organic salts, are a novel class of compounds with unique properties and a combinatorially great chemical diversity. Ionic liquids are utilized as synthesis and dispersion media for nanoparticles as well as for surface functionalization. Ionic liquid and nanoparticle hybrid systems are governed by a combined effect of several intermolecular interactions between their constituents. For each interaction, including van der Waals, electrostatic, structural, solvophobic, steric, and hydrogen bonding, the characterization and quantitative calculation methods together with factors affecting these interactions are reviewed here. Various self-organized structures based on nanoparticles in ionic liquids are generated as a result of a balance of these intermolecular interactions. These structures, including colloidal glasses and gels, lyotropic liquid crystals, nanoparticle-stabilized ionic liquid-containing emulsions, ionic liquid surface-functionalized nanoparticles, and nanoscale ionic materials, possess properties of both ionic liquids and nanoparticles, which render them useful as novel materials especially in electrochemical and catalysis applications. This review of the interactions within nanoparticle dispersions in ionic liquids and of the structure of nanoparticle and ionic liquid hybrids provides guidance on the rational design of novel ionic liquid-based materials, enabling applications in broad areas.

  11. A mechanism for supercooling in organic liquids

    SciTech Connect

    Thoma, P.E.

    1996-12-31

    In this investigation, a mechanism for supercooling inorganic liquids is formulated. By comparing the melting temperature and spontaneous freezing temperature of the chemicals evaluated with their molecular characteristics, the factors promoting supercooling are developed. The results obtained indicate that the following molecular characteristics promote supercooling in organic liquids: an unequal sharing of electrons between the atoms of a molecule; a three-dimensional chemical structure; a permanent, three-dimensional, and partially charged pocket within the chemical structure; a partially charged projection having a charge opposite that of the pocket and located on the side of the molecule opposite that of the pocket.

  12. Sources of polyatomic ions of organic liquids.

    PubMed

    Takaoka, G H; Takeuchi, M; Ryuto, H

    2010-02-01

    We have developed two types of liquid ion sources, one of which was a polyatomic ion source using liquid organic materials with a high-vapor pressure. Liquid materials such as octane and ethanol could be heated up to a maximum temperature of 100 degrees C, and the vapors were introduced into an ion source. They were ionized by an electron bombardment method and extracted from the ionizer. The ion current obtained at an extraction voltage of 2 kV was 230 microA for octane and several fragment ions such as alkyl ions were produced. On the other hand, another type of polyatomic ion source using alkyl naphthalene mixed with ionic liquid such as imidazolium dicyanamide has been developed. Instead of the electron bombardment method, a high-electric field method was used for the ion-emission from a sharp tip, because the vapor pressure of the liquid materials was relatively low. The threshold voltage was approximately 4.5 kV and the ion current of approximately 250 nA was obtained at an extraction voltage of 9.5 kV.

  13. Solidification of oils and organic liquids

    SciTech Connect

    Clark, D.E.; Colombo, P.; Neilson, R.M. Jr.

    1982-07-01

    The suitability of selected solidification media for application in the disposal of low-level oil and other organic liquid wastes has been investigated. In the past, these low-level wastes (LLWs) have commonly been immobilized by sorption onto solid absorbents such as vermiculite or diatomaceous earth. Evolving regulations regarding the disposal of these materials encourage solidification. Solidification media which were studied include Portland type I cement; vermiculite plus Portland type I cement; Nuclear Technology Corporation's Nutek 380-cement process; emulsifier, Portland type I cement-sodium silicate; Delaware Custom Materiel's cement process; and the US Gypsum Company's Envirostone process. Waste forms have been evaluated as to their ability to reliably produce free standing monolithic solids which are homogeneous (macroscopically), contain < 1% free standing liquids by volume and pass a water immersion test. Solidified waste form specimens were also subjected to vibratory shock testing and flame testing. Simulated oil wastes can be solidified to acceptable solid specimens having volumetric waste loadings of less than 40 volume-%. However, simulated organic liquid wastes could not be solidified into acceptable waste forms above a volumetric loading factor of about 10 volume-% using the solidification agents studied.

  14. Method and apparatus for destroying organic contaminants in aqueous liquids

    DOEpatents

    Donaldson, Terrence L.; Wilson, James H.

    1993-01-01

    A method and apparatus for destroying organic contaminants, such as trichloroethylene, in aqueous liquids, such as groundwater, utilizing steam stripping integrated with biodegradation. The contaminated aqueous liquid is fed into a steam stripper causing the volatilization of essentially all of the organic contaminants and a portion of the aqueous liquid. The majority of the aqueous liquid is discharged from the steam stripper. The volatilized vapors are then condensed to the liquid phase and introduced into a bioreactor. The bioreactor contains methanotrophic microorganisms which convert the organic contaminants into mainly carbon dioxide. The effluent from the bioreactor is then recycled back to the steam stripper for further processing.

  15. Method and apparatus for destroying organic contaminants in aqueous liquids

    DOEpatents

    Donaldson, T.L.; Wilson, J.H.

    1993-09-21

    A method and apparatus for destroying organic contaminants, such as trichloroethylene, in aqueous liquids, such as groundwater, utilizing steam stripping integrated with biodegradation. The contaminated aqueous liquid is fed into a steam stripper causing the volatilization of essentially all of the organic contaminants and a portion of the aqueous liquid. The majority of the aqueous liquid is discharged from the steam stripper. The volatilized vapors are then condensed to the liquid phase and introduced into a bioreactor. The bioreactor contains methanotrophic microorganisms which convert the organic contaminants into mainly carbon dioxide. The effluent from the bioreactor is then recycled back to the steam stripper for further processing. 2 figures.

  16. Investigation of the organic matter in inactive nuclear tank liquids

    SciTech Connect

    Schenley, R.L.; Griest, W.H.

    1990-08-01

    Environmental Protection Agency (EPA) methodology for regulatory organics fails to account for the organic matter that is suggested by total organic carbon (TOC) analysis in the Oak Ridge National Laboratory (ORNL) inactive nuclear waste-tank liquids and sludges. Identification and measurement of the total organics are needed to select appropriate waste treatment technologies. An initial investigation was made of the nature of the organics in several waste-tank liquids. This report details the analysis of ORNL wastes.

  17. Method for removing organic liquids from aqueous solutions and mixtures

    DOEpatents

    Hrubesh, Lawrence W.; Coronado, Paul R.; Dow, Jerome P.

    2004-03-23

    A method for removing organic liquids from aqueous solutions and mixtures. The method employs any porous material preferably in granular form and having small pores and a large specific surface area, that is hydrophobic so that liquid water does not readily wet its surface. In this method, organics, especially organic solvents that mix with and are more volatile than water, are separated from aqueous solution by preferentially evaporating across the liquid/solid boundary formed at the surfaces of the hydrophobic porous materials. Also, organic solvents that are immiscible with water, preferentially wet the surfaces of the hydrophobic material and are drawn within the porous materials by capillary action.

  18. Liquid crystal-templated conducting organic polymers

    DOEpatents

    Stupp, Samuel I.; Hulvat, James F.

    2004-01-20

    A method of preparing a conductive polymeric film, includes providing a liquid crystal phase comprising a plurality of hydrophobic cores, the phase on a substrate, introducing a hydrophobic component to the phase, the component a conductive polymer precursor, and applying an electric potential across the liquid crystal phase, the potential sufficient to polymerize the said precursor.

  19. Extraction of organic compounds with room temperature ionic liquids.

    PubMed

    Poole, Colin F; Poole, Salwa K

    2010-04-16

    Room temperature ionic liquids are novel solvents with a rather specific blend of physical and solution properties that makes them of interest for applications in separation science. They are good solvents for a wide range of compounds in which they behave as polar solvents. Their physical properties of note that distinguish them from conventional organic solvents are a negligible vapor pressure, high thermal stability, and relatively high viscosity. They can form biphasic systems with water or low polarity organic solvents and gases suitable for use in liquid-liquid and gas-liquid partition systems. An analysis of partition coefficients for varied compounds in these systems allows characterization of solvent selectivity using the solvation parameter model, which together with spectroscopic studies of solvent effects on probe substances, results in a detailed picture of solvent behavior. These studies indicate that the solution properties of ionic liquids are similar to those of polar organic solvents. Practical applications of ionic liquids in sample preparation include extractive distillation, aqueous biphasic systems, liquid-liquid extraction, liquid-phase microextraction, supported liquid membrane extraction, matrix solvents for headspace analysis, and micellar extraction. The specific advantages and limitations of ionic liquids in these studies is discussed with a view to defining future uses and the need not to neglect the identification of new room temperature ionic liquids with physical and solution properties tailored to the needs of specific sample preparation techniques. The defining feature of the special nature of ionic liquids is not their solution or physical properties viewed separately but their unique combinations when taken together compared with traditional organic solvents.

  20. Process for recovering organic components from liquid streams

    DOEpatents

    Blume, Ingo; Baker, Richard W.

    1991-01-01

    A separation process for recovering organic components from liquid streams. The process is a combination of pervaporation and decantation. In cases where the liquid stream contains the organic to be separated in dissolved form, the pervaporation step is used to concentrate the organic to a point above the solubility limit, so that a two-phase permeate is formed and then decanted. In cases where the liquid stream is a two-phase mixture, the decantation step is performed first, to remove the organic product phase, and the residue from the decanter is then treated by pervaporation. The condensed permeate from the pervaporation unit is sufficiently concentrated in the organic component to be fed back to the decanter. The process can be tailored to produce only two streams: an essentially pure organic product stream suitable for reuse, and a residue stream for discharge or reuse.

  1. A Guided Inquiry Liquid/Liquid Extractions Laboratory for Introductory Organic Chemistry

    ERIC Educational Resources Information Center

    Raydo, Margaret L.; Church, Megan S.; Taylor, Zane W.; Taylor, Christopher E.; Danowitz, Amy M.

    2015-01-01

    A guided inquiry laboratory experiment for teaching liquid/liquid extractions to first semester undergraduate organic chemistry students is described. This laboratory is particularly useful for introductory students as the analytes that are separated are highly colored dye molecules. This allows students to track into which phase each analyte…

  2. A Guided Inquiry Liquid/Liquid Extractions Laboratory for Introductory Organic Chemistry

    ERIC Educational Resources Information Center

    Raydo, Margaret L.; Church, Megan S.; Taylor, Zane W.; Taylor, Christopher E.; Danowitz, Amy M.

    2015-01-01

    A guided inquiry laboratory experiment for teaching liquid/liquid extractions to first semester undergraduate organic chemistry students is described. This laboratory is particularly useful for introductory students as the analytes that are separated are highly colored dye molecules. This allows students to track into which phase each analyte…

  3. Hierarchical organization in liquid crystal-in-liquid crystal emulsions.

    PubMed

    Mushenheim, Peter C; Abbott, Nicholas L

    2014-11-21

    We report the formation and characterization of hierarchical ordering in systems comprised of micrometer-sized droplets of thermotropic nematic liquid crystals (LCs) dispersed in continuous nematic phases of a lyotropic chromonic LC (disodium cromoglycate (DSCG)). Significantly, we find the orientations of the two LC phases to be coupled, with nematic droplets of 4'-pentyl-4-cyanobiphenyl (5CB) exhibiting a bipolar configuration with an axis of symmetry aligned orthogonal to the far-field director of the DSCG phase. We determine that this coupling of orientations does not result from either anisometric LC droplet shape or interfacial ionic phenomena but rather is consistent with the influence of van der Waals interactions that arise from the anisotropic polarizabilities of nematic 5CB (Δn = +0.18) and DSCG (Δn = -0.02) phases. We also find that it is possible to rotate and uniformly align the nematic droplets by using a weak magnetic field (B ∼ 0.3 T). An analysis of the dynamics of relaxation of the orientations of the 5CB droplets following removal of the magnetic field reveals the DSCG and 5CB droplets to be coupled by energies of ∼10(4) kT, consistent with a simple theoretical estimate of the influence of anisotropic van der Waals interactions. We also observed the nematic 5CB droplets to form dimers and larger assemblies mediated by the elasticity of the nematic DSCG. Overall, these results reveal that LC-in-LC emulsions define a new class of hierarchically ordered soft matter in which both thermotropic and lyotropic LCs are coupled in their ordering.

  4. Hierarchical Organization in Liquid Crystal-in-Liquid Crystal Emulsions

    PubMed Central

    Mushenheim, Peter C.

    2014-01-01

    We report the formation and characterization of hierarchical ordering in systems comprised of micrometer-sized droplets of thermotropic nematic liquid crystals (LCs) dispersed in continuous nematic phases of a lyotropic chromonic LC (disodium cromoglycate (DSCG)). Significantly, we find the orientations of the two LC phases to be coupled, with nematic droplets of 4′-pentyl-4-cyanobiphenyl (5CB) exhibiting a bipolar configuration with an axis of symmetry aligned orthogonal to the far-field director of the DSCG phase. We determine that this coupling of orientations does not result from either anisometric LC droplet shape or interfacial ionic phenomena but rather is consistent with the influence of van der Waals interactions that arise from the anisotropic polarizabilities of nematic 5CB (Δn = + 0.18) and DSCG (Δn = − 0.02) phases. We also find that it is possible to rotate and uniformly align the nematic droplets by using a weak magnetic field (B ∼ 0.3 T). An analysis of the dynamics of relaxation of the orientations of the 5CB droplets following removal of the magnetic field reveals the DSCG and 5CB droplets to be coupled by energies of ∼104kT, consistent with a simple theoretical estimate of the influence of anisotropic van der Waals interactions. We also observed the nematic 5CB droplets to form dimers and larger assemblies mediated by the elasticity of the nematic DSCG. Overall, these results reveal that LC-in-LC emulsions define a new class of hierarchically ordered soft matter in which both thermotropic and lyotropic LCs are coupled in their ordering. PMID:25278032

  5. Reactive uptake of NO3 by liquid and frozen organics

    NASA Astrophysics Data System (ADS)

    Moise, T.; Talukdar, R. K.; Frost, G. J.; Fox, R. W.; Rudich, Y.

    2002-01-01

    The reactive uptake of the NO3 radical by liquid and frozen organics was studied in a rotating wall flow tube coupled to a White cell. The organic liquids used included alkanes, alkenes, an alcohol, and carboxylic acids with conjugated and nonconjugated unsaturated bonds.. The reactive uptake coefficients, γ, of NO3 on n-hexadecane, 1-octadecene, 1-hexadecene, cis + trans 7-tetradecene, n-octanoic acid, 2,2,4,4,6,8,8 heptamethyl nonane, 1-octanol, cis, trans 9,11 and 10,12 octadecadienoic acid, cis-9, cis-12 octadecadienoic acid were determined. The reactive uptake coefficients measured with the organic liquids varied from 1.4 × 10-3 to 1.5 × 10-2. The uptake coefficients of NO3 by n-hexadecane and n-octanoic acid decreased by a factor of ~5 upon freezing. This behavior is explained by reaction occurring in the bulk of the organic liquid as well as on the surface. For the rest of the compounds the change in values of γ upon freezing of the liquids was within the experimental uncertainty. This is attributed to predominant uptake of NO3 by the top few molecular surface layers of the organic substrate and continuous replenishment of the surface layer by evaporation and/or mobility of the surface. These conclusions are corroborated by estimation of the diffuso-reactive length and solubility constant of NO3 in these liquids. The reactivity of NO3 with the organic surfaces is shown to correlate well with the known gas-phase chemistry of NO3. The effect on the atmospheric chemistry of the NO3 radical due to its interaction with organic aerosols is studied using an atmospheric box model applying realistic atmospheric scenarios. The inclusion of NO3 uptake on organic aerosol can decrease the NO3 lifetime by 10% or more.

  6. Thermomorphic phase separation in ionic liquid-organic liquid systems--conductivity and spectroscopic characterization.

    PubMed

    Riisager, Anders; Fehrmann, Rasmus; Berg, Rolf W; van Hal, Roy; Wasserscheid, Peter

    2005-08-21

    Electrical conductivity, FT-Raman and NMR measurements are demonstrated as useful tools to probe and determine phase behavior of thermomorphic ionic liquid-organic liquid systems. To illustrate the methods, consecutive conductivity measurements of a thermomorphic methoxyethoxyethyl-imidazolium ionic liquid/1-hexanol system are performed in the temperature interval 25-80 degrees C using a specially constructed double-electrode cell. In addition, FT-Raman and 1H-NMR spectroscopic studies performed on the phase-separable system in the same temperature interval confirm the mutual solubility of the components in the system, the liquid-liquid equilibrium phase diagram of the binary mixture, and signify the importance of hydrogen bonding between the ionic liquid and the hydroxyl group of the alcohol.

  7. [Utilization of organic resources in paper pulp waste liquid].

    PubMed

    Lin, Qiaojia; Liu, Jinghong; Yang, Guidi; Huang, Biao

    2005-04-01

    In this paper, one hundred percent of condensed sulfate paper pulp waste liquid was used as the raw material of adhesive, and the activation of its lignin as well as the improving effects of phenol formaldehyde resin and polyfunctional aqueous polymer isocyanate (PAPI) were studied. The results showed that adding formaldehyde to the waste liquid could increase the reactivity of contained lignin, and adding 30% phenol formaldehyde resin or 20% PAPI could make the waste liquid in place of pure phenol formaldehyde resin for producing class I plywood. Furthermore, the cost could be reduced by 55.5% and 49.0%, respectively, in comparing with pure phenol formaldehyde resin. This approach fully used the organic resources in paper pulp waste liquid, reduced environment pollution at the same time, and had unexceptionable economic, social and ecological benefits. The feasibility of preparing adhesives from paper pulp waste liquid was also analyzed by infrared spectrum.

  8. Designing Kitaev Spin Liquids in Metal-Organic Frameworks

    NASA Astrophysics Data System (ADS)

    Yamada, Masahiko G.; Fujita, Hiroyuki; Oshikawa, Masaki

    2017-08-01

    Kitaev's honeycomb lattice spin model is a remarkable exactly solvable model, which has a particular type of spin liquid (Kitaev spin liquid) as the ground state. Although its possible realization in iridates and α -RuCl3 has been vigorously discussed recently, these materials have substantial non-Kitaev direct exchange interactions and do not have a spin liquid ground state. We propose metal-organic frameworks (MOFs) with Ru3 + (or Os3 + ), forming the honeycomb lattice as promising candidates for a more ideal realization of Kitaev-type spin models, where the direct exchange interaction is strongly suppressed. The great flexibility of MOFs allows generalization to other three-dimensional lattices for the potential realization of a variety of spin liquids, such as a Weyl spin liquid.

  9. Dual Ionic and Organic Nature of Ionic Liquids.

    PubMed

    Shi, Rui; Wang, Yanting

    2016-01-19

    Inherited the advantages of inorganic salts and organic solvents, ionic liquids (ILs) exhibit many superior properties allowing them promising green solvents for the future. Although it has been widely acknowledged that the unique features of ILs originate from their dual ionic and organic nature, its microscopic physical origin still remains blurry. In this work, by comparing the ion/molecule cage structures obtained from molecular dynamics simulations for seven prototypic liquids--a molten inorganic salt, four ILs, a strongly polar organic solvent, and a weakly polar organic solvent, we have revealed that the depth of the cage energy landscape characterizes the ionic nature of ILs, whereas the slope and curvature of its mimimum determine the organic nature of ILs. This finding advances our understanding of ILs and thus will help their efficient utilization as well as the systematic design of novel functionalized ILs.

  10. Liquid Organic Fertilizers for Sustainable Agriculture: Nutrient Uptake of Organic versus Mineral Fertilizers in Citrus Trees

    PubMed Central

    Martínez-Alcántara, Belén; Martínez-Cuenca, Mary-Rus; Bermejo, Almudena; Legaz, Francisco; Quiñones, Ana

    2016-01-01

    The main objective of this study was to compare the performance of two liquid organic fertilizers, an animal and a plant-based fertilizer, with mineral fertilization on citrus trees. The source of the fertilizer (mineral or organic) had significant effect in the nutritional status of the organic and conventionally managed mandarins. Nutrient uptake, vegetative growth, carbohydrate synthesis and soil characteristics were analyzed. Results showed that plants fertilized with animal based liquid fertilizers exhibited higher total biomass with a more profuse development of new developing organs (leaves and fibrous roots). Liquid organic fertilization resulted in an increased uptake of macro and micronutrients compared to mineral fertilized trees. Moreover, organic fertilization positively affected the carbohydrate content (fructose, glucose and sucrose) mainly in summer flush leaves. Liquid organic fertilization also resulted in an increase of soil organic matter content. Animal-based fertilizer, due to intrinsic composition, increased total tree biomass and carbohydrate leaves content, and led to lower soil nitrate concentration and higher P and Mg exchangeable in soil extract compared to vegetal-based fertilizer. Therefore, liquid organic fertilizers could be used as an alternative to traditional mineral fertilization in drip irrigated citrus trees. PMID:27764099

  11. Liquid Organic Fertilizers for Sustainable Agriculture: Nutrient Uptake of Organic versus Mineral Fertilizers in Citrus Trees.

    PubMed

    Martínez-Alcántara, Belén; Martínez-Cuenca, Mary-Rus; Bermejo, Almudena; Legaz, Francisco; Quiñones, Ana

    2016-01-01

    The main objective of this study was to compare the performance of two liquid organic fertilizers, an animal and a plant-based fertilizer, with mineral fertilization on citrus trees. The source of the fertilizer (mineral or organic) had significant effect in the nutritional status of the organic and conventionally managed mandarins. Nutrient uptake, vegetative growth, carbohydrate synthesis and soil characteristics were analyzed. Results showed that plants fertilized with animal based liquid fertilizers exhibited higher total biomass with a more profuse development of new developing organs (leaves and fibrous roots). Liquid organic fertilization resulted in an increased uptake of macro and micronutrients compared to mineral fertilized trees. Moreover, organic fertilization positively affected the carbohydrate content (fructose, glucose and sucrose) mainly in summer flush leaves. Liquid organic fertilization also resulted in an increase of soil organic matter content. Animal-based fertilizer, due to intrinsic composition, increased total tree biomass and carbohydrate leaves content, and led to lower soil nitrate concentration and higher P and Mg exchangeable in soil extract compared to vegetal-based fertilizer. Therefore, liquid organic fertilizers could be used as an alternative to traditional mineral fertilization in drip irrigated citrus trees.

  12. Investigation of the reactivity of organic materials in liquid oxygen

    NASA Technical Reports Server (NTRS)

    Chamberlain, D.; Irwin, K.; Kirshen, N.; Mill, T.; Stringham, R.

    1970-01-01

    Measurements of impact-ignition sensitivity and studies of the relative reactivity of t-butoxy and t-butyl peroxy radicals toward a variety of organic compounds reveal improved methods of selection of materials for safe use in a liquid oxygen environment.

  13. Liquidization of dewatered organic sludge and anaerobic treatment

    SciTech Connect

    Sawayama, Shigeki; Inoue, Seiichi; Ogi, Tomoko

    1996-12-31

    Dewatered sewage sludge was thermochemically liquidized at 175 {degrees}C and the liquidized sludge was separated by centrifugation to 58% (w/w) supernatant and 42% precipitate. The amount of proteins in the liquidized sludge slightly decreased through the liquidization process, however, that of lipids increased. The supernatant separated from the sludge liquidized with dewatered sewage sludge was successfully anaerobically digested. Biogas yield from the supernatant from dewatered sewage sludge at organic loading concentrations of 1.9-2.2 g VS/l during 9 days incubation was 440 ml/g-added VS and digestion ratio was 66% (w/w). Biogas yield in the case of dewatered sewage sludge was 257 ml/g-added VS and digestion ratio was 45%. Similar results were obtained in the case of the anaerobically digested with sewage sludge and dewatered sludge. Anaerobic digestion of the supernatants from the liquidized sludges resulted in high biogas productivity and high digestion ratio compared with these of the original sludges. Moreover, the precipitates contained lower moisture, therefore, they can be incinerated easier than the respective original sludges.

  14. Photochemical Degradation of Organic Pollutants in Liquid Water and Ice

    NASA Astrophysics Data System (ADS)

    Sprenkle, A. M.; Grannas, A. M.

    2006-12-01

    Arctic snow and ice play an important role as reactive media in the environment. A variety of species are photochemically generated from snow/ice, including carbonyl compounds, alkyl halides, molecular halogens, and nitrogen oxides. However, the fate of anthropogenic organic pollutants in snow and ice is largely unknown. Volatile pollutants evaporate from lower, warmer latitudes and condense out in the higher, colder latitudes by a process known as global distillation, leading to enhanced concentrations of a variety of pollutants in polar regions. Here we present recent results of photochemical degradation studies of several important organic pollutants including aldrin, dieldrin, hexachlorobenzene, and 3,3',4,5'-tetrachlorobiphenyl. Direct and indirect (with H2O2) pathways were studied in both liquid water and ice forms. Aldrin and 3,3',4,5'-tetrachlorobiphenyl have shown the most reactivity, both degrading significantly via the direct and indirect pathway in liquid water and ice. Dieldrin has shown reactivity under both direct and indirect liquid conditions, while HCB is only reactive under indirect liquid conditions. These results indicate that ice can serve as an important reactive surface for anthropogenic organic pollutants. Snow/ice photochemistry should be included in models of pollutant fate, but further studies are necessary to determine which pollutants are most affected by ice photochemistry under typical environmental conditions.

  15. Tetraalkylphosphonium polyoxometalate ionic liquids : novel, organic-inorganic hybrid materials.

    SciTech Connect

    Rickert, P. G.; Antonio, M. P.; Firestone, M. A.; Kubatko, K.-A.; Szreder, T.; Wishart, J. F.; Dietz, M. L.; Chemistry; Univ. of Notre Dame; BNL

    2007-01-01

    Pairing of a Keggin or Lindqvist polyoxometalate (POM) anion with an appropriate tetraalkylphosphonium cation is shown to yield the first members of a new family of ionic liquids (ILs). Detailed characterization of one of them, an ambient-temperature 'liquid POM' comprising the Lindqvist salt of the trihexyl(tetradecyl) phosphonium cation, by voltammetry, viscometry, conductimetry, and thermal analysis indicates that it exhibits conductivity and viscosity comparable to those of the one previously described inorganic-organic POM-IL hybrid but with substantially improved thermal stability.

  16. NOCHAR Polymers: An Aqueous and Organic Liquid Solidification Process for Cadarache LOR (Liquides Organiques Radioactifs) - 13195

    SciTech Connect

    Vaudey, Claire-Emilie; Renou, Sebastien; Porco, Julien; Kelley, Dennis; Cochaud, Chantal

    2013-07-01

    To handle the Very Low Level Waste (VLLW) and the Low Level Waste (LLW) in France, two options can be considered: the incineration at CENTRACO facility and the disposal facility on ANDRA sites. The waste acceptance in these radwaste routes is dependent upon the adequacy between the waste characteristics (physical chemistry and radiological) and the radwaste route specifications. If the waste characteristics are incompatible with the radwaste route specifications (presence of significant quantities of chlorine, fluorine, organic component etc or/and high activity limits), it is necessary to find an alternative solution that consists of a waste pre-treatment process. In the context of the problematic Cadarache LOR (Liquides Organiques Radioactifs) waste streams, two radioactive scintillation cocktails have to be treated. The first one is composed of organic liquids at 13.1 % (diphenyloxazol, mesitylene, TBP, xylene) and water at 86.9 %. The second one is composed of TBP at 8.6 % and water at 91.4 %. They contain chlorine, fluorine and sulphate and have got alpha/beta/gamma spectra with mass activities equal to some kBq.g{sup -1}. Therefore, tritium is present and creates the second problematic waste stream. As a consequence, in order for disposal acceptance at the ANDRA site, it is necessary to pre-treat the waste. The NOCHAR polymers as an aqueous and organic liquid solidification process seem to be an adequate solution. Indeed, these polymers constitute an important variety of products applied to the treatment of radioactive aqueous and organic liquids (solvent, oil, solvent/oil mixing etc) and sludge through a mechanical and chemical solidification process. For Cadarache LOR, N910 and N960 respectively dedicated to the organic and aqueous liquids solidification are considered. With the N910, the organic waste solidification occurs in two steps. As the organic liquid travels moves through the polymer strands, the strands swell and immobilise the liquid. Then as the

  17. Structural studies of an organic liquid through the glass transition

    SciTech Connect

    Leheny, R.L.; Menon, N.; Nagel, S.R.; Long Price, D.; Suzuya, K.; Thiyagarajan, P.

    1996-11-01

    We have performed neutron diffraction experiments on deuterated propylene glycol, an organic glass former, at temperatures ranging from where its dynamical response approaches that of normal liquids to below the point where relaxation times appear to diverge. Our studies extend over a very broad range of scattering wave vector (0.01{lt}{ital Q}{lt}30 A{sup {minus}1}). In contrast to models which predict clustering, we find no evidence in the liquid at any temperature for heterogeneities large on molecular scales. However, we do note subtle changes at shorter lengths. Using molecular dynamics simulations to model our results, we identify these changes with increasing density and increasing orientational order induced by hydrogen bonding in the liquid as it cools. Analysis of the orientational correlations between molecules reveals a strong dependence on their relative positions. {copyright} {ital 1996 American Institute of Physics.}

  18. Dual Ionic and Organic Nature of Ionic Liquids

    PubMed Central

    Shi, Rui; Wang, Yanting

    2016-01-01

    Inherited the advantages of inorganic salts and organic solvents, ionic liquids (ILs) exhibit many superior properties allowing them promising green solvents for the future. Although it has been widely acknowledged that the unique features of ILs originate from their dual ionic and organic nature, its microscopic physical origin still remains blurry. In this work, by comparing the ion/molecule cage structures obtained from molecular dynamics simulations for seven prototypic liquids—a molten inorganic salt, four ILs, a strongly polar organic solvent, and a weakly polar organic solvent, we have revealed that the depth of the cage energy landscape characterizes the ionic nature of ILs, whereas the slope and curvature of its mimimum determine the organic nature of ILs. This finding advances our understanding of ILs and thus will help their efficient utilization as well as the systematic design of novel functionalized ILs. PMID:26782660

  19. Enhanced performance of dicationic ionic liquid electrolytes by organic solvents

    NASA Astrophysics Data System (ADS)

    Li, Song; Zhang, Pengfei; Fulvio Pasquale, F.; Hillesheim Patrick, C.; Feng, Guang; Dai, Sheng; Cummings Peter, T.

    2014-07-01

    The use of dicationic ionic liquid (DIL) electrolytes in supercapacitors is impeded by the slow dynamics of DILs, whereas the addition of organic solvents into DIL electrolytes improves ion transport and then enhances the power density of supercapacitors. In this work, the influences of organic solvents on the conductivity of DILs and the electrical double layer (EDL) of DIL-based supercapacitors are investigated using classical molecular dynamics simulation. Two types of organic solvents, acetonitrile (ACN) and propylene carbonate (PC), were used to explore the effects of different organic solvents on the EDL structure and capacitance of DIL/organic solvent-based supercapacitors. Firstly, it was found that the conductivity of DIL electrolytes was greatly enhanced in the presence of the organic solvent ACN. Secondly, a stronger adsorption of PC on graphite results in different EDL structures formed by DIL/ACN and DIL/PC electrolytes. The expulsion of co-ions from EDLs was observed in DIL/organic solvent electrolytes rather than neat DILs and this feature is more evident in DIL/PC. Furthermore, the bell-shaped differential capacitance-electric potential curve was not essentially changed by the presence of organic solvents. Comparing DIL/organic solvent electrolytes with neat DILs, the capacitance is slightly increased by organic solvents, which is in agreement with experimental observation.

  20. Enhanced performance of dicationic ionic liquid electrolytes by organic solvents.

    PubMed

    Li, Song; Zhang, Pengfei; Fulvio Pasquale, F; Hillesheim Patrick, C; Feng, Guang; Dai, Sheng; Cummings Peter, T

    2014-07-16

    The use of dicationic ionic liquid (DIL) electrolytes in supercapacitors is impeded by the slow dynamics of DILs, whereas the addition of organic solvents into DIL electrolytes improves ion transport and then enhances the power density of supercapacitors. In this work, the influences of organic solvents on the conductivity of DILs and the electrical double layer (EDL) of DIL-based supercapacitors are investigated using classical molecular dynamics simulation. Two types of organic solvents, acetonitrile (ACN) and propylene carbonate (PC), were used to explore the effects of different organic solvents on the EDL structure and capacitance of DIL/organic solvent-based supercapacitors. Firstly, it was found that the conductivity of DIL electrolytes was greatly enhanced in the presence of the organic solvent ACN. Secondly, a stronger adsorption of PC on graphite results in different EDL structures formed by DIL/ACN and DIL/PC electrolytes. The expulsion of co-ions from EDLs was observed in DIL/organic solvent electrolytes rather than neat DILs and this feature is more evident in DIL/PC. Furthermore, the bell-shaped differential capacitance-electric potential curve was not essentially changed by the presence of organic solvents. Comparing DIL/organic solvent electrolytes with neat DILs, the capacitance is slightly increased by organic solvents, which is in agreement with experimental observation.

  1. Liquid Crystals for Organic Field-Effect Transistors

    NASA Astrophysics Data System (ADS)

    O'Neill, Mary; Kelly, Stephen M.

    Columnar, smectic and lamellar polymeric liquid crystals are widely recognized as very promising charge-transporting organic semiconductors due to their ability to spontaneously self-assemble into highly ordered domains in uniform thin films over large areas. The transport properties of smectic and columnar liquid crystals are discussed in Chaps. 2 (10.1007/978-90-481-2873-0_2) and 3 (10.1007/978-90-481-2873-0_3). Here we examine their application to organic field-effect transistors (OFETs): after a short introduction in Sect. 9.1 we introduce the OFET configuration and show how the mobility is measured in Sect. 9.2. Section 9.3 discusses polymeric liquid crystalline semiconductors in OFETs. We review research that shows that annealing of polymers in a fluid mesophase gives a more ordered microcrystalline morphology on cooling than that kinetically determined by solution processing of the thin film. We also demonstrate the benefits of monodomain alignment and show the application of liquid crystals in light-emitting field-effect transistors. Some columnar and smectic phases are highly ordered with short intermolecular separation to give large π-π coupling. We discuss their use in OFETs in Sects. 9.4, and 9.5 respectively. Section 9.6 summarises the conclusions of the chapter.

  2. Ionic Liquids as Tool to Improve Enzymatic Organic Synthesis.

    PubMed

    Itoh, Toshiyuki

    2017-08-09

    Ionic liquids (ILs) have now been acknowledged as reaction media for biotransformations. The first three examples were reported in this field in 2000, and since then, numerous applications have been reported for biocatalytic reactions using ILs. Two topics using ILs for enzymatic reactions have been reviewed from the standpoint of biocatalyst mediating organic synthesis; the first is "Biocatalysis in Ionic Liquids" which includes various types of biocatalytic reactions in ILs (section 2): (1) recent examples of lipase-mediated reactions using ILs as reaction media for biodiesel oil production and for sugar ester production, (2) oxidase-catalyzed reactions in ILs, (3) laccase-catalyzed reactions, (4) peroxidase-catalyzed reactions, (4) cytochrome-mediated reactions, (5) microbe-mediated hydrations, (6) protease-catalyzed reactions, (8) whole cell mediated asymmetric reduction of ketones, (10) acylase-catalyzed reactions, (11) glycosylation or cellulase-mediated hydrolysis of polysaccharides, (12) hydroxynitrile lyase-catalyzed reaction, (13) fluorinase or haloalkane dehydrogenase-catalyzed reaction, (14) luciferase-catalyzed reactions, and (15) biocatalytic promiscuity of enzymatic reactions for organic synthesis using ILs. The second is "Enzymes Activated by Ionic Liquids for Organic Synthesis", particularly describing the finding story of activation of lipases by the coating with a PEG-substituted IL (section 3). The author's opinion toward "Future Perspectives of Using ILs for Enzymatic Reactions" has also been discussed in section 4.

  3. Gas-liquid chromatography in lunar organic analysis.

    NASA Technical Reports Server (NTRS)

    Gehrke, C. W.

    1972-01-01

    Gas-liquid chromatography (GLC) is a powerful and sensitive method for the separation and detection of organic compounds at nanogram levels. The primary requirement for successful analyses is that the compounds of interest must be volatile under the chromatographic conditions employed. Nonvolatile organic compounds must be converted to volatile derivatives prior to analysis. The derivatives of choice must be both amenable to chromatographic separation and be relatively stable. The condition of volatility necessitates the development of efficient derivatization reactions for important groups of compounds as amino acids, carbohydrates, nucleosides, etc. Trimethylsilylation and trifluoroacetylation represent specific areas of recent prominence. Some relevant practical aspects of GLC are discussed.

  4. Gas-liquid chromatography in lunar organic analysis.

    NASA Technical Reports Server (NTRS)

    Gehrke, C. W.

    1972-01-01

    Gas-liquid chromatography (GLC) is a powerful and sensitive method for the separation and detection of organic compounds at nanogram levels. The primary requirement for successful analyses is that the compounds of interest must be volatile under the chromatographic conditions employed. Nonvolatile organic compounds must be converted to volatile derivatives prior to analysis. The derivatives of choice must be both amenable to chromatographic separation and be relatively stable. The condition of volatility necessitates the development of efficient derivatization reactions for important groups of compounds as amino acids, carbohydrates, nucleosides, etc. Trimethylsilylation and trifluoroacetylation represent specific areas of recent prominence. Some relevant practical aspects of GLC are discussed.

  5. Solidification of floating organic droplet in dispersive liquid-liquid microextraction as a green analytical tool.

    PubMed

    Mansour, Fotouh R; Danielson, Neil D

    2017-08-01

    Dispersive liquid-liquid microextraction (DLLME) is a special type of microextraction in which a mixture of two solvents (an extracting solvent and a disperser) is injected into the sample. The extraction solvent is then dispersed as fine droplets in the cloudy sample through manual or mechanical agitation. Hence, the sample is centrifuged to break the formed emulsion and the extracting solvent is manually separated. The organic solvents commonly used in DLLME are halogenated hydrocarbons that are highly toxic. These solvents are heavier than water, so they sink to the bottom of the centrifugation tube which makes the separation step difficult. By using solvents of low density, the organic extractant floats on the sample surface. If the selected solvent such as undecanol has a freezing point in the range 10-25°C, the floating droplet can be solidified using a simple ice-bath, and then transferred out of the sample matrix; this step is known as solidification of floating organic droplet (SFOD). Coupling DLLME to SFOD combines the advantages of both approaches together. The DLLME-SFOD process is controlled by the same variables of conventional liquid-liquid extraction. The organic solvents used as extractants in DLLME-SFOD must be immiscible with water, of lower density, low volatility, high partition coefficient and low melting and freezing points. The extraction efficiency of DLLME-SFOD is affected by types and volumes of organic extractant and disperser, salt addition, pH, temperature, stirring rate and extraction time. This review discusses the principle, optimization variables, advantages and disadvantages and some selected applications of DLLME-SFOD in water, food and biomedical analysis. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Reversible Acid Gas Capture Using CO2-Binding Organic Liquids

    SciTech Connect

    Heldebrant, David J.; Koech, Phillip K.; Yonker, Clement R.; Rainbolt, James E.; Zheng, Feng

    2010-08-31

    Acid gas scrubbing technology is predominantly aqueous alkanolamine based. Of the acid gases, CO2, H2S and SO2 have been shown to be reversible, however there are serious disadvantages with corrosion and high regeneration costs. The primary scrubbing system composed of monoethanolamine is limited to 30% by weight because of the highly corrosive solution. This gravimetric limitation limits the CO2 volumetric (≤108 g/L) and gravimetric capacity (≤7 wt%) of the system. Furthermore the scrubbing system has a large energy penalty from pumping and heating the excess water required to dissolve the MEA bicarbonate salt. Considering the high specific heat of water (4 j/g-1K-1), low capacities and the high corrosion we set out to design a fully organic solvent that can chemically bind all acid gases i.e. CO2 as reversible alkylcarbonate ionic liquids or analogues thereof. Having a liquid acid gas carrier improves process economics because there is no need for excess solvent to pump and to heat. We have demonstrated illustrated in Figure 1, that CO2-binding organic liquids (CO2BOLs) have a high CO2 solubility paired with a much lower specific heat (<1.5 J/g-1K-1) than aqueous systems. CO2BOLs are a subsection of a larger class of materials known as Binding Organic Liquids (BOLs). Our BOLs have been shown to reversibly bind and release COS, CS2, and SO2, which we denote COSBOLS, CS2BOLs and SO2BOLs. Our BOLs are highly tunable and can be designed for post or pre-combustion gas capture. The design and testing of the next generation zwitterionic CO2BOLs and SO2BOLs are presented.

  7. Group extraction of organic compounds present in liquid samples

    NASA Technical Reports Server (NTRS)

    Jahnsen, Vilhelm J. (Inventor)

    1976-01-01

    An extraction device is disclosed comprising a tube containing a substantially inert, chemically non-reactive packing material with a large surface area to volume ratio. A sample which consists of organic compounds dissolved in a liquid, is introduced into the tube. As the sample passes through the packing material it spreads over the material's large surface area to form a thin liquid film which is held on the packing material in a stationary state. A particular group or family of compounds is extractable from the sample by passing a particular solvent system consisting of a solvent and selected reagents through the packing material. The reagents cause optimum conditions to exist for the compounds of the particular family to pass through the phase boundary between the sample liquid and the solvent of the solvent system. Thus, the compounds of the particular family are separated from the sample liquid and become dissolved in the solvent of the solvent system. The particular family of compounds dissolved in the solvent, representing an extract, exits the tube together with the solvent through the tube's nozzle, while the rest of the sample remains on the packing material in a stationary state. Subsequently, a different solvent system may be passed through the packing material to extract another family of compounds from the remaining sample on the packing material.

  8. Liquid crystalline composites toward organic photovoltaic application (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Shimizu, Yo; Sosa-Vargas, Lydia; Shin, Woong; Higuchi, Yumi; Itani, Hiromichi; Kawano, Koki; Dao, Quang Duy; Fujii, Akihiko; Ozaki, Masanori

    2017-02-01

    Liquid crystalline semiconductor is an interesting category of organic electronic materials and also has been extensively studied in terms of "Printed Electronics". For the wider diversity in research toward new applications, one can consider how to use a combination of miscibility and phase separation in liquid crystals. Here we report discotic liquid crystals in making a composite of which structural order is controlled in nano-scale toward photovoltaic applications. Discotic columnar LCs were studied on their resultant molecular order and carrier transport properties. Liquid crystals of phthalocyanine and its analogues which exhibit columnar mesomorphism with high carrier mobility (10-1 cm2/Vs) were examined with making binary phase diagrams and the correlation to carrier transport properties by TOF measurements was discussed. The shape-analogues in chemical structure shows a good miscibility even for the different lattice-type of columnar arrangement and the carrier mobility is mostly decrease except for a case of combination with a metal-free and the metal complex. For the mixtures with non-mesogenic C60 derivatives, one sees a phase-separated structure due to its immiscibility, though the columnar order is remained in a range of component ratio.Especially, in a range of the ratio, it was observed the phase separated C60 derivatives are fused into the matrix of columnar bundles, indicating C60 derivatives could be diffused in columnar arrays in molecular level.

  9. "Liquid-liquid-solid"-type superoleophobic surfaces to pattern polymeric semiconductors towards high-quality organic field-effect transistors.

    PubMed

    Wu, Yuchen; Su, Bin; Jiang, Lei; Heeger, Alan J

    2013-12-03

    Precisely aligned organic-liquid-soluble semiconductor microwire arrays have been fabricated by "liquid-liquid-solid" type superoleophobic surfaces directed fluid drying. Aligned organic 1D micro-architectures can be built as high-quality organic field-effect transistors with high mobilities of >10 cm(2) ·V(-1) ·s(-1) and current on/off ratio of more than 10(6) . All these studies will boost the development of 1D microstructures of organic semiconductor materials for potential application in organic electronics. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Design and Synthesis of Novel Liquid Crystals and Organic Semiconductors

    NASA Astrophysics Data System (ADS)

    Wang, Kunlun

    Liquid crystals have found wide applications due to their unique properties. In order to search for new nematic liquid crystal compounds with relatively low phase transition temperatures, a series of [1,2,3]-triazole-based mesogens and LC dimers were synthesized via the "Click Reaction" under mild conditions and their phase behavior will be presented. Meanwhile, hydrogen-bonded complexes mixed by benzonitrile derivatives and aromatic acetylenes are obtained and their thermal behavior examined. In order to achieve a better understanding of the influence of difluorination on the oligophenyls, a series of partially fluorinated oligomers were obtained and some of their physical properties are compared. Organic semiconductors possess many advantages compared to conventional inorganic semiconductors. Perfluorination was utilized in our molecular design for the synthesis of 1,3,5-triphenyl benzene derivatives and self-assembled crystals via nitrogen-iodine halogen bonding and the target molecules might show some interesting semicondocting properties.

  11. The aquatic impact of ionic liquids on freshwater organisms.

    PubMed

    Costa, Susana P F; Pinto, Paula C A G; Saraiva, M Lúcia M F S; Rocha, Fábio R P; Santos, Joyce R P; Monteiro, Regina T R

    2015-11-01

    Ionic liquids (ILs), also known as liquid electrolytes, are powerful solvents with a wide variety of academic and industrial applications. Bioassays with aquatic organisms constitute an effective tool for the evaluation of ILs' toxicity, as well as for the prediction and identification of possible moieties that act as toxicophores. In this work, the acute toxicity of six ILs and two commonly used organic solvents was evaluated using freshwater organisms: Daphnia magna, Raphidocelis subcapitata and Hydra attenuata. The bioassays were performed by exposing the organisms to increasing concentrations of the ILs and observing D. magna immobilization, R. subcapitata growth inhibition, and the morphological or mortality effects in H. attenuata. The results demonstrate that the tested organisms are not equally susceptible to the ILs, e.g., bmpyr [BF4] was the least toxic compound for R. subcapitata, N1,1 [N1,1,1OOH] for D. magna and emim [Tf2N] for H. attenuata. This highlights the importance of applying a battery of assays in toxicological analysis. Additionally, Hydra proved to be the most tolerant species to the tested ILs. According to their hazard rankings, the tested ILs are considered practically harmless or moderately toxic, except (Hex)3(TDec)P [Cl], which was classified as highly toxic. The ILs were revealed to be more harmful to aquatic systems than the tested organic solvents, reaffirming the need to analyze carefully the (eco)toxicological impact of these compounds. The present study provides additional data in the evaluation of the potential hazard and the impact of ILs in the environment.

  12. Liquid-liquid phase separation in atmospheric aerosol particles: dependence on organic functionalities and mixture complexity

    NASA Astrophysics Data System (ADS)

    Song, M.; Marcolli, C.; Krieger, U. K.; Zuend, A.; Peter, T.

    2012-04-01

    In the troposphere, aerosol particles undergo phase transitions such as deliquescence and efflorescence during humidity cycles (Marcolli and Krieger, 2006). In addition, interactions between organic and inorganic compounds lead to liquid-liquid phase separation (LLPS) (Ciobanu et al., 2009). Recent studies on a limited number of model systems have shown that oxygen-to-carbon ratios (O:C) of the organic aerosol fraction might be a good predictor for LLPS in mixed organic/ammonium sulfate (AS) particles (Bertram et al., 2011; Song et al., 2011). However, in order to corroborate this hypothesis experiments with an organic fraction that consists of a higher number of components with different O:C ratios and functional groups are needed. In order to determine the influence of O:C ratio, the specific organic functionalities and the mixture complexity on LLPS, we subjected organic/AS particles deposited on a hydrophobically coated substrate to relative humidity (RH) cycles and observed phase changes using optical microscopy and micro-Raman spectroscopy. To determine the influence of mixture complexity, we mixed together up to 10 organic compounds. We also prepared mixtures that were rich in different types of functional groups like polyols, aromatics and dicarboxylic acids which were identified from field measurements. We screened for a miscibility gap by varying the organic-to-inorganic ratio from 2:1 to 1:6. AS in the investigated single particles effloresced at 27 - 50 %RH and deliquesced at 72 - 79 %RH during humidity cycles. The occurrence of LLPS is determined to a high degree by the O:C of the organics: there was no LLPS for mixtures with O:C > 0.8 and there was always LLPS for mixtures with O:C < 0.57. In the range in between, we observed a dependence on the specific functional groups: a high share of aromatic functionalities shifts the range of O:C for which LLPS occurs to lower values. A correlation was also found for the onset RH of LLPS as a function of O

  13. Thermochemical Energy Storage through De/Hydrogenation of Organic Liquids: Reactions of Organic Liquids on Metal Hydrides.

    PubMed

    Ulmer, Ulrich; Cholewa, Martin; Diemant, Thomas; Bonatto Minella, Christian; Dittmeyer, Roland; Behm, R Jürgen; Fichtner, Maximilian

    2016-06-08

    A study of the reactions of liquid acetone and toluene on transition metal hydrides, which can be used in thermal energy or hydrogen storage applications, is presented. Hydrogen is confined in TiFe, Ti0.95Zr0.05Mn1.49V0.45Fe0.06 ("Hydralloy C5"), and V40Fe8Ti26Cr26 after contact with acetone. Toluene passivates V40Fe8Ti26Cr26 completely for hydrogen desorption while TiFe is only mildly deactivated and desorption is not blocked at all in the case of Hydralloy C5. LaNi5 is inert toward both organic liquids. Gas chromatography (GC) investigations reveal that CO, propane, and propene are formed during hydrogen desorption from V40Fe8Ti26Cr26 in liquid acetone, and methylcyclohexane is formed in the case of liquid toluene. These reactions do not occur if dehydrogenated samples are used, which indicates an enhanced surface reactivity during hydrogen desorption. Significant amounts of carbon-containing species are detected at the surface and subsurface of acetone- and toluene-treated V40Fe8Ti26Cr26 by X-ray photoelectron spectroscopy (XPS). The modification of the surface and subsurface chemistry and the resulting blocking of catalytic sites is believed to be responsible for the containment of hydrogen in the bulk. The surface passivation reactions occur only during hydrogen desorption of the samples.

  14. Processing liquid organic wastes at the NNL Preston laboratory

    SciTech Connect

    Coppersthwaite, Duncan; Greenwood, Howard; Docrat, Tahera; Allinson, Sarah; Sultan, Ruqayyah; May, Sarah

    2013-07-01

    Organic compounds of various kinds have been used in the nuclear industry for numerous duties in uranium chemical, metal and ceramic processing plants. In the course of the various operations undertaken, these organic compounds have become contaminated with uranic material, either accidentally or as an inevitable part of the process. Typically, the chemical/physical form and/or concentration of the uranic content of the organics has prevented disposal. In order to address the issue of contaminated liquid organic wastes, the National Nuclear Laboratory (NNL) has developed a suite of treatments designed to recover uranium and to render the waste suitable for disposal. The developed processes are operated at industrial scale via the NNL Preston Laboratory Residue Processing Plant. The Oil Waste Leaching (OWL) Process is a fully industrialised process used for the treatment of contaminated oils with approximately 200 tonnes of uranium contaminated oil being treated to date. The process was originally developed for the treatment of contaminated tributyl phosphate and odourless kerosene which had been adsorbed onto sawdust. However, over the years, the OWL process has been refined for a range of oils including 'water emulsifiable' cutting oils, lubricating oils, hydraulic oils/fluids and 'Fomblin' (fully fluorinated) oils. Chemically, the OWL process has proved capable of treating solvents as well as oils but the highly volatile/flammable nature of many solvents has required additional precautions compared with those required for oil treatment. These additional precautions led to the development of the Solvent Treatment Advanced Rig (STAR), an installation operated under an inert atmosphere. STAR is a small 'module' (100 dm{sup 3} volume) which allows the treatment of both water miscible and immiscible solvents. This paper discusses the challenges associated with the treatment of liquid organic wastes and the process developments which have allowed a wide range of

  15. Ionic-liquid-supported (ILS) catalysts for asymmetric organic synthesis.

    PubMed

    Ni, Bukuo; Headley, Allan D

    2010-04-19

    The asymmetric synthesis of compounds that contain new C-C and C-O bonds remains one of the most important types of synthesis in organic chemistry. Over the years, many different types of catalysts have been designed and used effectively to carry out such transformations. Ionic-liquid-supported (ILS) catalysts represent a new and very effective class of catalysts that are used to facilitate the asymmetric synthesis of such compounds. There are many advantages to using ILS catalysts; they are nontoxic, environmentally benign, and, most important, recyclable. An overview of the design, synthesis, mode of action, and effectiveness of this class of catalysts is reported.

  16. Positronium signature in organic liquid scintillators for neutrino experiments

    SciTech Connect

    Franco, D.; Consolati, G.; Trezzi, D.

    2011-01-15

    Electron antineutrinos are commonly detected in liquid scintillator experiments via inverse {beta} decay by looking at the coincidence between the reaction products: neutrons and positrons. Prior to positron annihilation, an electron-positron pair may form an orthopositronium (o-Ps) state, with a mean lifetime of a few nanoseconds. Even if the o-Ps decay is speeded up by spin-flip or pick-off effects, it may introduce distortions in the photon emission time distribution, crucial for position reconstruction and pulse shape discrimination algorithms in antineutrino experiments. Reversing the problem, the o-Ps-induced time distortion represents a new signature for tagging antineutrinos in liquid scintillator. In this article, we report the results of measurements of the o-Ps formation probability and lifetime for the most used solvents for organic liquid scintillators in neutrino physics (pseudocumene, linear alkyl benzene, phenylxylylethane, and dodecane). We characterize also a mixture of pseudocumene +1.5 g/l of 2,5-diphenyloxazole, a fluor acting as wavelength shifter. In the second part of the article, we demonstrate that the o-Ps-induced distortion of the scintillation photon emission time distributions represent an optimal signature for tagging positrons on an event by event basis, potentially enhancing the antineutrino detection.

  17. Liquid water and organics in Comets: implications for exobiology

    NASA Astrophysics Data System (ADS)

    Wickramasinghe, J. T.; Wickramasinghe, N. C.; Wallis, M. K.

    2009-10-01

    Liquid water in comets, once considered impossible, now appears to be almost certain. New evidence has come from the discovery of clay minerals in comet Tempel 1, which compliments the indirect evidence in aqueous alteration of carbonaceous chondrites. Infrared spectral indication of clay is confirmed by modelling data in the 8-40 μm and 8-12 μm wavebands on the basis of mixtures of clays and organics. Radiogenic heating producing liquid water cores in freshly formed comets appears more likely on current evidence for solar system formation. A second possibility investigated here is transient melting in comets in the inner solar system, where thin crusts of asphalt-like material, formed due to solar processing and becoming hot in the daytime, can cause melting of sub-surface icy material a few centimetres deep. Supposing comets were seeded with microbes at the time of their formation from pre-solar material, there would be plenty of time for exponential amplification and evolution within the liquid interior and in the transient ponds or lakes formed as the outer layers are stripped away via sublimation.

  18. Liquid Water and Organics in Comets: Implications for Exobiology

    NASA Astrophysics Data System (ADS)

    Wickramasinghe, J. T.; Wickramasinghe, N. C.; Wallis, M. K.

    Liquid water in comets, once considered impossible, now appears to be almost certain. New evidence has come from the discovery of clay minerals in comet Tempel 1, which complements the indirect evidence in aqueous alteration of carbonaceous chondrites. Infrared spectral indication of clay is confirmed by modelling data in the 8-40 μm and 8-12 μm wavebands on the basis of mixtures of clays and organics. Radiogenic heating producing liquid water cores in freshly formed comets appears more likely on current evidence for solar system formation. A second possibility investigated here is transient melting in comets in the inner solar system, where thin crusts of asphalt-like material, formed due to solar processing and becoming hot in the daytime, can cause melting of sub-surface icy material a few centimetres deep. Supposing comets were seeded with microbes at the time of their formation from pre-solar material, there would be plenty of time for exponential amplification and evolution within the liquid interior and in the transient ponds or lakes formed as the outer layers are stripped away via sublimation.

  19. Angstrom-Resolved Metal-Organic Framework-Liquid Interfaces.

    PubMed

    Chiodini, Stefano; Reinares-Fisac, Daniel; Espinosa, Francisco M; Gutiérrez-Puebla, Enrique; Monge, Angeles; Gándara, Felipe; Garcia, Ricardo

    2017-09-11

    Metal-organic frameworks (MOFs) are a class of crystalline materials with a variety of applications in gas storage, catalysis, drug delivery or light harvesting. The optimization of those applications requires the characterization of MOF structure in the relevant environment. Dynamic force microscopy has been applied to follow dynamic processes of metal-organic-framework material. We provide images with spatial and time resolutions, respectively, of angstrom and seconds that show that Ce-RPF-8 surfaces immersed in water and glycerol experience a surface reconstruction process that is characterized by the diffusion of the molecular species along the step edges of the open terraces. The rate of the surface reconstruction process depends on the liquid. In water it happens spontaneously while in glycerol is triggered by applying an external force.

  20. Acid Gas Capture Using CO2-Binding Organic Liquids

    SciTech Connect

    Heldebrant, David J.; Koech, Phillip K.; Rainbolt, James E.; Zheng, Feng

    2010-11-10

    Current chemical CO2 scrubbing technology is primarily aqueous alkanolamine based. These systems rapidly bind CO2 (forming water-soluble carbamate and bicarbonate salts) however, the process has serious disadvantages. The concentration of monoethanolamine rarely exceeds 30 wt % due to the corrosive nature of the solution, and this reduces the maximum CO2 volumetric (≤108 g/L) and gravimetric capacity (≤7 wt%) of the CO2 scrubber. The ≤30 wt % loading of ethanolamine also means that a large excess of water must be pumped and heated during CO2 capture and release, and this greatly increases the energy requirements especially considering the high specific heat of water (4 j/g-1K-1). Our approach is to switch to organic systems that chemically bind CO2 as liquid alkylcarbonate salts. Our CO2-binding organic liquids have higher CO2 solubility, lower specific heats, potential for less corrosion and lower binding energies for CO2 than aqueous systems. CO2BOLs also reversibly bind and release mixed sulfur oxides. Furthermore the CO2BOL system can be direct solvent replacements for any solvent based CO2 capture systems because they are commercially available reagents and because they are fluids they would not require extensive process re-engineering.

  1. Controlled Growth of Organic Semiconductor Films Using Liquid Crystal Solvents

    NASA Astrophysics Data System (ADS)

    Bufkin, Kevin; Ohlson, Brooks; Hillman, Ben; Johnson, Brad; Patrick, David

    2008-05-01

    Interest in using organic semiconductors in applications such as large area displays, photovoltaic devices, and RFID tags stems in part from their prospects for enabling significantly reduced manufacturing costs compared to traditional inorganic semiconductors. However many of the best performing prototype devices produced so far have involved expensive or time-consuming fabrication methods, such as the use of single crystals or thin films deposited under high vacuum conditions. We present a new approach for growing low molecular weight organic crystalline films at ambient conditions based on a vapor-liquid-solid growth mechanism using thermotropic nematic liquid crystal (LC) solvents. Tetracene is deposited via atmospheric-pressure sublimation onto substrates coated by a LC layer oriented using rubbed polyimide, producing films that are highly crystalline, with large grain sizes, and possessing macroscopic uniaxial orientation. This poster will describe the growth mechanism, discuss the effects of processing conditions such as LC layer thickness, substrate temperature and flux rate, and compare the results to a model of deposition-diffusion aggregation accounting for the finite thickness of the solvent layer.

  2. Controlled Growth of Organic Semiconductor Films Using Liquid Crystal Solvents

    NASA Astrophysics Data System (ADS)

    Bufkin, Kevin; Ohlson, Brooks; Hillman, Ben; Johnson, Brad; Patrick, David

    2008-03-01

    Interest in using organic semiconductors in applications such as large area displays, photovoltaic devices, and RFID tags stems in part from their prospects for enabling significantly reduced manufacturing costs compared to traditional inorganic semiconductors. However many of the best performing prototype devices produced so far have involved expensive or time-consuming fabrication methods, such as the use of single crystals or thin films deposited under high vacuum conditions. We present a new approach for growing low molecular weight organic crystalline films at ambient conditions based on a vapor-liquid-solid growth mechanism using thermotropic nematic liquid crystal (LC) solvents. Tetracene is deposited via atmospheric-pressure sublimation onto substrates coated by a LC layer oriented using rubbed polyimide, producing films that are highly crystalline, with large grain sizes, and possessing macroscopic uniaxial orientation. This poster will describe the growth mechanism, discuss the effects of processing conditions such as LC layer thickness, substrate temperature and flux rate, and compare the results to a model of diffusion limited aggregation accounting for the finite thickness of the solvent layer.

  3. Contaminants in Liquid Organic Fertilizers Used for Agriculture in Japan.

    PubMed

    Hai, Dao M; Qiu, Xuchun; Xu, Hai; Honda, Masato; Yabe, Mitsuyasu; Kadokami, Kiwao; Shimasaki, Yohei; Oshima, Yuji

    2017-07-01

    To provide an overview of anthropogenic contaminants in liquid organic fertilizers (LOFs), products from four biogas plants in Kyushu, Japan, were analyzed for a wide range of contaminants, including copper, cadmium, tributyltin (TBT), dibutyltin (DBT), perfluorooctane sulfonate, 952 semi-volatile organic compounds, and 89 antibiotics. The highest concentrations of copper (31.1 mg/L) and cadmium (0.08 mg/L) were found in LOFs from the Hita biogas plant. Only ofloxacin and sulfapyridine were detected in total 89 antibiotics screened. TBT, DBT, and perfluorooctane sulfonate were present at low concentrations in the LOFs from all four locations. Among the 952 semi-volatile organic compounds, 78 compounds were detected in at least one sample and were present at concentrations between 1.2 and 139.6 mg/L. On the basis of comparisons with previous studies and quality standards for the use of organic fertilizers, the concentrations of contaminants in the studied LOFs indicate that they might be safe for agricultural purposes.

  4. On the implications of aerosol liquid water and phase separation for organic aerosol mass

    EPA Science Inventory

    Organic compounds and liquid water are major aerosol constituents in the southeast United States (SE US). Water associated with inorganic constituents (inorganic water) can contribute to the partitioning medium for organic aerosol when relative humidities or organic matter to org...

  5. On the implications of aerosol liquid water and phase separation for organic aerosol mass

    EPA Science Inventory

    Organic compounds and liquid water are major aerosol constituents in the southeast United States (SE US). Water associated with inorganic constituents (inorganic water) can contribute to the partitioning medium for organic aerosol when relative humidities or organic matter to org...

  6. Pyridinium ionic liquid-based liquid-solid extraction of inorganic and organic iodine from Laminaria.

    PubMed

    Peng, Li-Qing; Yu, Wen-Yan; Xu, Jing-Jing; Cao, Jun

    2018-01-15

    A simple, green and effective extraction method, namely, pyridinium ionic liquid- (IL) based liquid-solid extraction (LSE), was first designed to extract the main inorganic and organic iodine compounds (I(-), monoiodo-tyrosine (MIT) and diiodo-tyrosine (DIT)). The optimal extraction conditions were as follows: ultrasonic intensity 100W, IL ([EPy]Br) concentration 200mM, extraction time 30min, liquid/solid ratio 10mL/g, and pH value 6.5. The morphologies of Laminaria were studied by scanning electron microscopy and transmission electron microscopy. The recovery values of I(-), MIT and DIT from Laminaria were in the range of 88% to 94%, and limits of detection were in the range of 59.40 to 283.6ng/g. The proposed method was applied to the extraction and determination of iodine compounds in three Laminaria. The results showed that IL-based LSE could be a promising method for rapid extraction of bioactive iodine from complex food matrices. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Liquid-liquid phase separation in particles containing secondary organic material free of inorganic salts

    NASA Astrophysics Data System (ADS)

    Song, Mijung; Liu, Pengfei; Martin, Scot T.; Bertram, Allan K.

    2017-09-01

    Particles containing secondary organic material (SOM) are ubiquitous in the atmosphere and play a role in climate and air quality. Recently, research has shown that liquid-liquid phase separation (LLPS) occurs at high relative humidity (RH) (greater than ˜ 95 %) in α-pinene-derived SOM particles free of inorganic salts, while LLPS does not occur in isoprene-derived SOM particles free of inorganic salts. We expand on these findings by investigating LLPS at 290 ± 1 K in SOM particles free of inorganic salts produced from ozonolysis of β-caryophyllene, ozonolysis of limonene, and photo-oxidation of toluene. LLPS was observed at greater than ˜ 95 % RH in the biogenic SOM particles derived from β-caryophyllene and limonene while LLPS was not observed in the anthropogenic SOM particles derived from toluene. This work combined with the earlier work on LLPS in SOM particles free of inorganic salts suggests that the occurrence of LLPS in SOM particles free of inorganic salts is related to the oxygen-to-carbon elemental ratio (O : C) of the organic material. These results help explain the difference between the hygroscopic parameter κ of SOM particles measured above and below water saturation in the laboratory and field, and have implications for predicting the cloud condensation nucleation properties of SOM particles.

  8. Removal of organic impurities from liquid carbon dioxide

    NASA Astrophysics Data System (ADS)

    Zito, Richard R.

    2002-09-01

    The use of a high velocity stream of carbon dioxide snowflakes to clean large optics is well known, and has gained widespread acceptance in the astronomical community as a telescope maintenance technique. Ultimately, however, the success of carbon dioxide snow cleaning depends on the availability of high purity carbon dioxide. The higher the purity of the carbon dioxide, the longer will be the time interval between required mirror washings. The highest grades of commercially produced liquid carbon dioxide are often not available in the more remote regions of the world - such as where major astronomical observatories are often located. Furthermore, the purity of even the highest grades of carbon dioxide are only nominal, and wide variations are known to occur from tank to tank. Occasionally, visible deposits of organic impurities are left behind during cleaning with carbon dioxide that is believed to be 99.999% pure. A zeolite molecular sieve based filtration system has proven to be very effective in removing these organic impurities. A zeolite is a complex alumino-silicate. One example has an empirical formula of Na2O(Al2O3)(SiO2)2yH2O, where y=0 to 8. The zeolites have an open crystal structure and are capable of trapping impurities like 8-methylheptadecane (an oil) and 2,6-octadine-1-ol,3,7- dimethyl-,(E)- (a fatty acid). In fact, a zeolite can trap 29.5% of its own weight in SAE 20 lubricant at 25 degree(s)C. After filtration of liquid CO2 through zeolites, the concentration of measured impurities was below the detection limit for state-of-the-art gas chromatography systems.

  9. Organic liquid scintillation detector shape and volume impact on radiation portal monitors

    NASA Astrophysics Data System (ADS)

    Paff, Marc G.; Clarke, Shaun D.; Pozzi, Sara A.

    2016-07-01

    We have developed and tested a radiation portal monitor using organic liquid scintillation detectors. In order to optimize our system designs, neutron measurements were carried out with three organic liquid scintillation detectors of different shapes and sizes, along with a 3He radiation portal monitor (RPM) as a reference. The three liquids tested were a 7.62 cm diameter by 7.62 cm length cylindrical active volume organic liquid scintillation detector, a 12.7 cm diameter by 12.7 cm length cylindrical active volume organic liquid scintillation detector, and a 25 cm by 25 cm by 10 cm "paddle" shaped organic liquid scintillation detector. Background and Cf-252 neutron measurements were recorded to allow for a comparison of neutron intrinsic efficiencies as well as receiver operating characteristics (ROC) curves between detectors. The 12.7 cm diameter cylindrical active volume organic liquid scintillation detector exhibited the highest intrinsic neutron efficiency (54%) of all three liquid scintillators. An ROC curve analysis for a heavily moderated Cf-252 measurement showed that using the 12.7 cm diameter by 12.7 cm length cylindrical active volume Eljen EJ309 organic liquid scintillation detector would result in the fewest needed detector units in order to achieve a near 100% positive neutron alarm rate while maintaining a better than 1 in 10,000 false alarm rate on natural neutron background. A small number of organic liquid scintillation detectors could therefore be a valid alternative to 3He in some RPM applications.

  10. Catalytic conversion of nonfood woody biomass solids to organic liquids.

    PubMed

    Barta, Katalin; Ford, Peter C

    2014-05-20

    This Account outlines recent efforts in our laboratories addressing a fundamental challenge of sustainability chemistry, the effective utilization of biomass for production of chemicals and fuels. Efficient methods for converting renewable biomass solids to chemicals and liquid fuels would reduce society's dependence on nonrenewable petroleum resources while easing the atmospheric carbon dioxide burden. The major nonfood component of biomass is lignocellulose, a matrix of the biopolymers cellulose, hemicellulose, and lignin. New approaches are needed to effect facile conversion of lignocellulose solids to liquid fuels and to other chemical precursors without the formation of intractable side products and with sufficient specificity to give economically sustainable product streams. We have devised a novel catalytic system whereby the renewable feedstocks cellulose, organosolv lignin, and even lignocellulose composites such as sawdust are transformed into organic liquids. The reaction medium is supercritical methanol (sc-MeOH), while the catalyst is a copper-doped porous metal oxide (PMO) prepared from inexpensive, Earth-abundant starting materials. This transformation occurs in a single stage reactor operating at 300-320 °C and 160-220 bar. The reducing equivalents for these transformations are derived by the reforming of MeOH (to H2 and CO), which thereby serves as a "liquid syngas" in the present case. Water generated by deoxygenation processes is quickly removed by the water-gas shift reaction. The Cu-doped PMO serves multiple purposes, catalyzing substrate hydrogenolysis and hydrogenation as well as the methanol reforming and shift reactions. This one-pot "UCSB process" is quantitative, giving little or no biochar residual. Provided is an overview of these catalysis studies beginning with reactions of the model compound dihydrobenzofuran that help define the key processes occurring. The initial step is phenyl-ether bond hydrogenolysis, and this is followed by

  11. Investigation of the organic matter in inactive nuclear tank liquids. Environmental Restoration Program

    SciTech Connect

    Schenley, R.L.; Griest, W.H.

    1990-08-01

    Environmental Protection Agency (EPA) methodology for regulatory organics fails to account for the organic matter that is suggested by total organic carbon (TOC) analysis in the Oak Ridge National Laboratory (ORNL) inactive nuclear waste-tank liquids and sludges. Identification and measurement of the total organics are needed to select appropriate waste treatment technologies. An initial investigation was made of the nature of the organics in several waste-tank liquids. This report details the analysis of ORNL wastes.

  12. Reactive Uptake of Ammonia and Formation of Organic Nitrogen Species for Non-Liquid/Liquid Secondary Organic Material

    NASA Astrophysics Data System (ADS)

    Martin, S. T.; Li, Y.; Liu, P.

    2015-12-01

    Formation of ammonium and organic nitrogen (ON) species was studied for secondary organic material (SOM) of variable viscosity, ranging from non-liquid to liquid physical states. The SOM was produced as particles of 50 to 150 nm in diameter in aerosol form from six precursors, including three terpenoid and three aromatic species. The viscosity of the hygroscopic SOM was adjusted by exposure to relative humidity (RH) from <5% to >90% RH in steps of 10% at 293 ± 2 K. The aerosol was subsequently exposed to 5 ppm NH3 for mean reaction times of 30, 370, or 5230 s. Ammonium and ON were characterized by high-resolution time-of-flight aerosol mass spectrometry (HR-ToF-AMS). The ammonium-to-organic ratio of mass concentrations (MNH4/MOrg) in the particles increased monotonically from <5% RH to a limiting value at a threshold RH, implicating a switchover in the reaction kinetics from a system limited by diffusivity within the SOM for low RH to one limited by other factors, such as saturated uptake, at higher RH. Formation of ON was observed for aromatic-derived SOMs, but not significant for terpenoid-derived SOMs. For aromatic-derived SOMs, the ON-to-organic ratio of mass concentrations (MON/MOrg) was negligible for RH <20%, increased monotonically from 20% to 60% RH, and stayed constant for RH >60%. The threshold RH for the switchover from kinetically controlled regime to a non-kinetically-controlled one was thus different between formation of ammonium and ON. This difference suggests that water may play a role in the slow reactions of ON formation as a reactant or a catalyst, in addition to affecting the reactant diffusion as in the fast reaction of ammonium formation. The implication is that formation of ammonium salts and organic nitrogen species by certain SOMs should be treated separately in chemical transport models to reflect the different roles of water that may affect the phase state of the SOMs or may act as a reactant or a catalyst.

  13. Azobenzene-based organic salts with ionic liquid and liquid crystalline properties

    SciTech Connect

    Stappert, Kathrin; Muthmann, Johanna; Spielberg, Eike T.; Mudring, Anja -Verena

    2015-07-23

    Two sets of new azobenzene-based bromide salts are synthesized, and their thermal photochromic properties are studied. Both sets are based on the imidazolium cation. The first set (1) features a symmetric biscation where two imidazolium head groups (Im) with different alkyl chains (Cn) are connected to a central azobenzene unit (Azo): [Azo(C1-Im-Cn)2]; n = 6, 8, 10, 12, 14. The other one contains an n-alkyl-imidazolium cation (Cn-Im) bearing a terminal azobenzene unit (C1-Azo) substituted with an alkoxy chain (O-Cm) of either two (2) or six (3) carbon atoms: [C1-Azo-O-Cm-Im-Cn]; m = 2, n = 8, 10, 12 and m = 6, n = 8, 10, 12, 14, 16. For both cation classes, the influence of alkyl chains of varying length on the thermal phase behavior was investigated by differential scanning calorimetry (DSC) and polarizing optical microscopy (POM). For five compounds (Azo(-C1-Im-C12)2 (1d), Azo(-C1-Im-C12)2 (1e), C1-Azo-O-C2-Im-C10 (2b), C1-Azo-O-C2-Im-C12 (2c), and C1-Azo-O-C6-Im-C16 (3e)), the formation of a liquid crystalline phase was observed. The biscationic salts (1) are all comparatively high melting organic salts (180–240 °C), and only the two representatives with long alkylchains (C12 and C14) exhibit liquid crystallinity. The monocationic salts with an O–C2 bridge (2) melt between 140 and 170 °C depending on the alkyl chain length, but from an alkyl chain of 10 and more carbon atoms on they form a smectic A liquid crystalline phase. The representatives of the third set with a O–C6 bridge qualify as ionic liquids with melting points less than 100 °C. However, only the representative with a hexadecyl chain forms a liquid crystalline phase. Representative single crystals for all sets of cations could be grown that allowed for single crystal structure analysis. Together with small-angle X-ray scattering experiments they allow for a more detailed understanding of the thermal properties. As a result, through irradiation with UV

  14. Azobenzene-based organic salts with ionic liquid and liquid crystalline properties

    DOE PAGES

    Stappert, Kathrin; Muthmann, Johanna; Spielberg, Eike T.; ...

    2015-07-23

    Two sets of new azobenzene-based bromide salts are synthesized, and their thermal photochromic properties are studied. Both sets are based on the imidazolium cation. The first set (1) features a symmetric biscation where two imidazolium head groups (Im) with different alkyl chains (Cn) are connected to a central azobenzene unit (Azo): [Azo(C1-Im-Cn)2]; n = 6, 8, 10, 12, 14. The other one contains an n-alkyl-imidazolium cation (Cn-Im) bearing a terminal azobenzene unit (C1-Azo) substituted with an alkoxy chain (O-Cm) of either two (2) or six (3) carbon atoms: [C1-Azo-O-Cm-Im-Cn]; m = 2, n = 8, 10, 12 and m =more » 6, n = 8, 10, 12, 14, 16. For both cation classes, the influence of alkyl chains of varying length on the thermal phase behavior was investigated by differential scanning calorimetry (DSC) and polarizing optical microscopy (POM). For five compounds (Azo(-C1-Im-C12)2 (1d), Azo(-C1-Im-C12)2 (1e), C1-Azo-O-C2-Im-C10 (2b), C1-Azo-O-C2-Im-C12 (2c), and C1-Azo-O-C6-Im-C16 (3e)), the formation of a liquid crystalline phase was observed. The biscationic salts (1) are all comparatively high melting organic salts (180–240 °C), and only the two representatives with long alkylchains (C12 and C14) exhibit liquid crystallinity. The monocationic salts with an O–C2 bridge (2) melt between 140 and 170 °C depending on the alkyl chain length, but from an alkyl chain of 10 and more carbon atoms on they form a smectic A liquid crystalline phase. The representatives of the third set with a O–C6 bridge qualify as ionic liquids with melting points less than 100 °C. However, only the representative with a hexadecyl chain forms a liquid crystalline phase. Representative single crystals for all sets of cations could be grown that allowed for single crystal structure analysis. Together with small-angle X-ray scattering experiments they allow for a more detailed understanding of the thermal properties. As a result, through irradiation with UV-light (320–366 nm) all

  15. Feasibility study of a gadolinium-loaded DIN-based liquid scintillator

    NASA Astrophysics Data System (ADS)

    Song, Sook Hyung; Joo, Kyung Kwang; So, Sun Heang; Yeo, In Sung

    2013-09-01

    DIN (di-isopropylnaphthalene) has a high flashpoint and can be used as a base solvent in liquid scintillators. It reduces safety concerns to humans and the environment. (PPO, 3 g/ ℓ) and (bis-MSB, 30 mg/ ℓ) were dissolved to formulate a DIN-based liquid scintillator (LS). A gadolinium (Gd) complex with carboxylic acid was synthesized using a neutralized chemical reaction. Then, 0.1% Gd was loaded into the LS. This Gd-loaded DIN-based LS using a solvent-solvent extraction method is the first attempt at a LS. In this study, we investigated the physical and the optical properties of this LS, and we will summarize all the characteristics of the Gd-loaded DIN-based LS.

  16. Improvement of natural pastures using liquid organic fertilizers

    NASA Astrophysics Data System (ADS)

    Ghambashidze, Giorgi; Gabedava, Giorgi; Abuladze, Paata

    2016-04-01

    Nowadays natural pastures remains the main source to supply livestock with fresh feed material in Georgia. Due to that common pasturelands are under continues grazing pressure and normally no measures are taken in order to improve pasture productivity and to protect soil from erosion. Unregulated stocking rate leads to overutilization of natural pastures causing reduction in productivity and soil fertility. It is especially evident in arid regions, where bare soil after removal of vegetation dries out and is subject to wind erosion. In many areas even with regulated stocking rate plant available soil nutrient pool is already diminished and vegetation cannot be recovered easily after grazing. Therefore it is essential to improve soil fertility, which provide adequate amount of nutrients to plants to regenerate. Ongoing study aims to compare effect of different types of organic fertilizers on natural pastures in combination with pasture rotation scheme in order to maintain soil fertility and prepare the basis for its gradual improvement. Initial results shows positive impact of liquid organic fertilizers which increased aboveground biomass production by 200-300 kg per hectare.

  17. Discotic liquid crystals: a new generation of organic semiconductors.

    PubMed

    Sergeyev, Sergey; Pisula, Wojciech; Geerts, Yves Henri

    2007-12-01

    Discotic (disc-like) molecules typically comprising a rigid aromatic core and flexible peripheral chains have been attracting growing interest because of their fundamental importance as model systems for the study of charge and energy transport and due to the possibilities of their application in organic electronic devices. This critical review covers various aspects of recent research on discotic liquid crystals, in particular, molecular design concepts, supramolecular structure, processing into ordered thin films and fabrication of electronic devices. The chemical structure of the conjugated core of discotic molecules governs, to a large extent, their intramolecular electronic properties. Variation of the peripheral flexible chains and of the aromatic core is decisive for the tuning of self-assembly in solution and in bulk. Supramolecular organization of discotic molecules can be effectively controlled by the choice of the processing methods. In particular, approaches to obtain suitable macroscopic orientations of columnar superstructures on surfaces, that is, planar uniaxial or homeotropic alignment, are discussed together with appropriate processing techniques. Finally, an overview of charge transport in discotic materials and their application in optoelectronic devices is given.

  18. Incineration of radioactive organic liquid wastes by underwater thermal plasma

    NASA Astrophysics Data System (ADS)

    Mabrouk, M.; Lemont, F.; Baronnet, J. M.

    2012-12-01

    This work deals with incineration of radioactive organic liquid wastes using an oxygen thermal plasma jet, submerged under water. The results presented here are focused on incineration of three different wastes: a mixture of tributylphosphate (TBP) and dodecane, a perfluoropolyether oil (PFPE) and trichloroethylene (TCE). To evaluate the plutonium behavior in used TBP/dodecane incineration, zirconium is used as a surrogate of plutonium; the method to enrich TBP/dodecane mixture in zirconium is detailed. Experimental set-up is described. During a trial run, CO2 and CO contents in the exhaust gas are continuously measured; samples, periodically taken from the solution, are analyzed by appropriate chemical methods: contents in total organic carbon (COT), phosphorus, fluoride and nitrates are measured. Condensed residues are characterized by RX diffraction and SEM with EDS. Process efficiency, during tests with a few L/h of separated or mixed wastes, is given by mineralization rate which is better than 99.9 % for feed rate up to 4 L/h. Trapping rate is also better than 99 % for phosphorous as for fluorine and chlorine. Those trials, with long duration, have shown that there is no corrosion problems, also the hydrogen chloride and fluoride have been neutralized by an aqueous solution of potassium carbonate.

  19. Determination of organic compounds in water using dispersive liquid-liquid microextraction.

    PubMed

    Rezaee, Mohammad; Assadi, Yaghoub; Milani Hosseini, Mohammad-Reza; Aghaee, Elham; Ahmadi, Fardin; Berijani, Sana

    2006-05-26

    A new microextraction technique termed dispersive liquid-liquid microextraction (DLLME) was developed. DLLME is a very simple and rapid method for extraction and preconcentration of organic compounds from water samples. In this method, the appropriate mixture of extraction solvent (8.0 microL C2Cl4) and disperser solvent (1.00 mL acetone) are injected into the aqueous sample (5.00 mL) by syringe, rapidly. Therefore, cloudy solution is formed. In fact, it is consisted of fine particles of extraction solvent which is dispersed entirely into aqueous phase. After centrifuging, the fine particles of extraction solvent are sedimented in the bottom of the conical test tube (5.0 +/- 0.2 microL). The performance of DLLME is illustrated with the determination of polycyclic aromatic hydrocarbons (PAHs) in water samples by using gas chromatography-flame ionization detection (GC-FID). Some important parameters, such as kind of extraction and disperser solvent and volume of them, and extraction time were investigated. Under the optimum conditions the enrichment factor ranged from 603 to 1113 and the recovery ranged from 60.3 to 111.3%. The linear range was 0.02-200 microg/L (four orders of magnitude) and limit of detection was 0.007-0.030 microg/L for most of analytes. The relative standard deviations (RSDs) for 2 microg/L of PAHs in water by using internal standard were in the range 1.4-10.2% (n = 5). The recoveries of PAHs from surface water at spiking level of 5.0 microg/L were 82.0-111.0%. The ability of DLLME technique in the extraction of other organic compounds such as organochlorine pesticides, organophosphorus pesticides and substituted benzene compounds (benzene, toluene, ethyl benzene, and xylenes) from water samples were studied. The advantages of DLLME method are simplicity of operation, rapidity, low cost, high recovery, and enrichment factor.

  20. Material degradation of liquid organic semiconductors analyzed by nuclear magnetic resonance spectroscopy

    SciTech Connect

    Fukushima, Tatsuya; Yamamoto, Junichi; Fukuchi, Masashi; Kaji, Hironori; Hirata, Shuzo; Jung, Heo Hyo; Adachi, Chihaya; Hirata, Osamu; Shibano, Yuki

    2015-08-15

    Liquid organic light-emitting diodes (liquid OLEDs) are unique devices consisting only of liquid organic semiconductors in the active layer, and the device performances have been investigated recently. However, the device degradation, especially, the origin has been unknown. In this study, we show that material degradation occurs in liquid OLEDs, whose active layer is composed of carbazole with an ethylene glycol chain. Nuclear magnetic resonance (NMR) experiments clearly exhibit that the dimerization reaction of carbazole moiety occurs in the liquid OLEDs during driving the devices. In contrast, cleavages of the ethylene glycol chain are not detected within experimental error. The dimerization reaction is considered to be related to the device degradation.

  1. Determination of optimal ionic liquid for organic single-crystal field-effect transistors

    NASA Astrophysics Data System (ADS)

    Ono, S.; Miwa, K.; Seki, S.

    2016-02-01

    We investigate organic single-crystal field-effect transistors with various ionic liquids as gate dielectric. We find that the mobility of the field-effect transistors for both p-type and n-type organic semiconductors increases with decreasing total capacitance of the ionic liquid. However, it does not depend on the ion species at the interface between the organic semiconductor and the ionic liquid. By choosing an appropriate ionic liquid, a high carrier mobility of 12.4 cm2/V s in rubrene single crystals (p-type) and 0.13 cm2/V s in 7.7.8.8-Tetracyanoquinodimethane single crystals (n-type) are achieved. This study clarifies the influence of ionic liquids on the device performance of organic field-effect transistors and shows a way to maximize carrier mobility at the solid/liquid interface.

  2. Multiwalled carbon nanotubes sensor for organic liquid detection at room temperature

    NASA Astrophysics Data System (ADS)

    Chaudhary, Deepti; Khare, Neeraj; Vankar, V. D.

    2016-04-01

    We have explored the possibility of using multiwalled carbon nanotubes (MWCNTs) as room temperature chemical sensor for the detection of organic liquids such as ethanol, propanol, methanol and toluene. MWCNTs were synthesized by thermal chemical vapor deposition (TCVD) technique. The interdigitated electrodes were fabricated by conventional photolithography technique. The sensor was fabricated by drop depositing MWCNT suspension onto the interdigitated electrodes. The sensing properties of MWCNTs sensor was studied for organic liquids detection. The resistance of sensor was found to increase upon exposure to these liquids. Sensor shows good reversibility and fast response at room temperature. Charge transfer between the organic liquid and sensing element is the dominant sensing mechanism.

  3. Tunable and flexible solvent-free liquid organic distributed feedback lasers

    NASA Astrophysics Data System (ADS)

    Kim, Ju-Hyung; Inoue, Munetomo; Zhao, Li; Komino, Takeshi; Seo, Soonmin; Ribierre, Jean-Charles; Adachi, Chihaya

    2015-02-01

    We report on optically pumped blue, green, and red liquid organic distributed feedback (DFB) lasers based on solvent-free fluidic organic semiconductors, and prepared on highly flexible corrugated polymeric patterns. By the appropriate selection of laser dyes doping a liquid 9-(2-ethylhexyl)carbazole host, the lasing wavelength is effectively tuned across the visible spectrum via a cascade energy transfer scheme. We also demonstrate a mechanical tunability of the flexible liquid DFB laser emission, which is due to the deformation of the high-aspect ratio DFB grating under bending. Overall, this work provides an important step in the development of flexible liquid organic optoelectronic devices.

  4. Electronic functionalization of solid-to-liquid interfaces between organic semiconductors and ionic liquids: Realization of very high performance organic single-crystal transistors

    NASA Astrophysics Data System (ADS)

    Uemura, T.; Hirahara, R.; Tominari, Y.; Ono, S.; Seki, S.; Takeya, J.

    2008-12-01

    High-performance electronic function of current amplification is realized with the use of solid-to-liquid interfaces between organic semiconductors and ionic liquid. To hold in place the ionic liquid of 1-ethyl-3-methyl-imidazolium bis(trifluoromethanesulfonyl)imide known for low viscosity and high ionic conductivity, an elastomeric well structure is fabricated with polydimethylsiloxane on which organic single crystals of rubrene are electrostatically attached. As the result of rapid formation of electric double layers in the ionic liquid interfacing, the high-mobility organic semiconductor crystals' fast-switching transistor function is demonstrated with the application of gate voltage, realizing the highest sheet transconductance, namely, amplifying performance, ever achieved.

  5. Tertiary phase diagram of cellulose, ionic liquid and organic solvent

    NASA Astrophysics Data System (ADS)

    Zhang, Xin; Henderson, Doug; Tyagi, Madhusudan; Mao, Yimin; Briber, Robert M.; Wang, Howard

    Cellulose is the most abundant natural polymer on earth, and widely used in products from clothing to paper. Fundamental understanding of molecular solutions of cellulose is the key to realize advanced technologies beyond cellulose fibers. It has been reported that certain ionic liquid/organic solvent mixtures dissolve cellulose. In this study, the tertiary phase diagram of microcrystalline cellulose, 1-Ethyl-3-methylimidazolium acetate (EMIMAc), and dimethylformamide (DMF) mixtures has been determined using optical cloud point method and small angle neutron scattering (SANS). Data indicate that a molar ratio of EMIMAc to cellulose repeating unit equal or greater than 3 is necessary but not sufficient in forming one-phase homogeneous solutions. A miscibility gap exists in the dilute regime, where a minimum of 5 mol% of EMIM Ac in DMF is needed to form homogenous solutions. SANS show that cellulose chains adopt Gaussian-like conformation in homogenous solutions. The solutions exhibit the characteristics of upper critical solution temperature. Clustering of cellulose chains occurs at low EMIMAc/DMF or EMIMAc/cellulose ratio, or at low temperatures. The mechanism of cellulose dissolution in tertiary mixture is discussed.

  6. Development of polyatomic ion beam system using liquid organic materials

    NASA Astrophysics Data System (ADS)

    Takaoka, G. H.; Nishida, Y.; Yamamoto, T.; Kawashita, M.

    2005-08-01

    We have developed a new type of polyatomic ion beam system using liquid organic materials such as octane and ethanol, which consists of a capillary type of nozzle, an ionizer, a mass-separator and a substrate holder. Ion current extracted after ionization was 430 μA for octane and 200 μA for ethanol, respectively. The mass-analysis was realized using a compact E × B mass filter, and the mass-analyzed ion beams were transferred toward the substrate. The ion current density at the substrate was a few μA/cm2 for the mass-separated ion species. Interactions of polyatomic ion beams with silicon (Si) surfaces were investigated by utilizing the ellipsometry measurement. It was found that the damaged layer thickness irradiated by the polyatomic ions with a mass number of about 40 was smaller than that by Ar ion irradiation at the same incident energy and ion fluence. The result indicated that the rupture of polyatomic ions occurred upon its impact on the Si surface with an incident energy larger than a few keV. In addition, the chemical modification of Si surfaces such as wettability could be achieved by adjusting the incident energy for the ethanol ions, which included all the fragment ions.

  7. Potential of Organic Matrix Composites for Liquid Oxygen Tank

    NASA Technical Reports Server (NTRS)

    Davis, Samuel E.; Herald, Stephen D.; Stolzfus, Joel M.; Engel, Carl D.; Bohlen, James W.; Palm, Tod; Robinson, Michael J.

    2005-01-01

    Composite materials are being considered for the tankage of cryogenic propellants in access to space because of potentially lower structural weights. A major hurdle for composites is an inherent concern about the safety of using flammable structural materials in contact with liquid and gaseous oxygen. A hazards analysis approach addresses a series of specific concerns that must be addressed based upon test data. Under the 2nd Generation Reusable Launch Vehicle contracts, testing was begun for a variety of organic matrix composite materials both to aid in the selection of materials and to provide needed test data to support hazards analyses. The work has continued at NASA MSFC and the NASA WSTF to provide information on the potential for using composite materials in oxygen systems. Appropriate methods for oxygen compatibility testing of structural materials and data for a range of composite materials from impact, friction, flammability and electrostatic discharge testing are presented. Remaining concerns and conclusions about composite tank structures, and recommendations for additional testing are discussed. Requirements for system specific hazards analysis are identified.

  8. Potential of Organic Matrix Composites for Liquid Oxygen Tank

    NASA Technical Reports Server (NTRS)

    Davis, Samuel E.; Herald, Stephen D.; Stolzfus, Joel M.; Engel, Carl D.; Bohlen, James W.; Palm, Tod; Robinson, Michael J.

    2005-01-01

    Composite materials are being considered for the tankage of cryogenic propellants in access to space because of potentially lower structural weights. A major hurdle for composites is an inherent concern about the safety of using flammable structural materials in contact with liquid and gaseous oxygen. A hazards analysis approach addresses a series of specific concerns that must be addressed based upon test data. Under the 2nd Generation Reusable Launch Vehicle contracts, testing was begun for a variety of organic matrix composite materials both to aid in the selection of materials and to provide needed test data to support hazards analyses. The work has continued at NASA MSFC and the NASA WSTF to provide information on the potential for using composite materials in oxygen systems. Appropriate methods for oxygen compatibility testing of structural materials and data for a range of composite materials from impact, friction, flammability and electrostatic discharge testing are presented. Remaining concerns and conclusions about composite tank structures, and recommendations for additional testing are discussed. Requirements for system specific hazards analysis are identified.

  9. Investigation of the Extinguishing Features for Liquid Fuels and Organic Flammable Liquids Atomized by a Water Flow

    NASA Astrophysics Data System (ADS)

    Voytkov, Ivan V.; Zabelin, Maksim V.; Vysokomornaya, Olga V.

    2016-02-01

    The processes of heat and mass transfer were investigated experimentally while moving and evaporating the atomized water flow in high-temperature combustion products of typical liquid fuels and organic flammable liquids: gasoline, kerosene, acetone, crude oil, industrial alcohol. We determined typical periods of liquid extinguishing by an atomized water flow of various dispersability. Data of the discharge of extinguishing medium corresponding to various parameters of atomization and duration of using the atomization devices was presented. It is shown that Um≈3.5 m/s is a minimal outflow velocity of droplets during moving while passing the distance of 1m in the high-temperature gas medium to stop the combustion of organic liquids.

  10. Determination of organic pollutants in coking wastewater by dispersive liquid-liquid microextraction/GC/MS.

    PubMed

    Song, Guoxin; Zhu, Chunyan; Hu, Yaoming; Chen, Jianmin; Cheng, Hefa

    2013-05-01

    A method based on dispersive liquid-liquid microextraction coupled with GC/MS was developed for quantitative analysis of the major organic pollutants listed in the United States Environmental Protection Agency method 8270 and the 15 European-priority polycyclic aromatic hydrocarbons in coking wastewater. The major parameters such as extraction solvent, dispersive solvent, solution pH, and extraction time were systematically optimized. The optimum extraction conditions were found to be: 15 μL mixture of 2:1 v/v carbon tetrachloride and chlorobenzene as the extraction solvent, 0.75 mL ACN as the dispersive solvent, solution pH of 8, and extraction time of 2 min. For the major pollutants listed in the United States Environmental Protection Agency 8270, the linear ranges were 0.1 to 100 mg/L, the enrichment factors ranged from 452 to 685, and the relative recoveries ranged from 67.5 to 103.5% with RSDs of 4.0-9.1% (n = 5) at the concentrations of 10 mg/L under the optimum extraction conditions. For the 15 polycyclic aromatic hydrocarbons, the linear ranges were 0.1 to 100 μg/L, the enrichment factors ranged from 645 to 723, and the relative recoveries ranged from 94.5 to 107.6% with RSDs of 4.6-9.0% (n = 5) at the concentrations of 10 μg/L. The usefulness of the developed method was demonstrated by applying it in the analysis of real-world coking wastewater samples. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Electric Field Effect on Phospholipid Monolayers at an Aqueous-Organic Liquid-Liquid Interface.

    PubMed

    Yu, Hao; Yzeiri, Irena; Hou, Binyang; Chen, Chiu-Hao; Bu, Wei; Vanysek, Petr; Chen, Yu-Sheng; Lin, Binhua; Král, Petr; Schlossman, Mark L

    2015-07-23

    The electric potential difference across cell membranes, known as the membrane potential, plays an important role in the activation of many biological processes. To investigate the effect of the membrane potential on the molecular ordering of lipids within a biomimetic membrane, a self-assembled monolayer of 1-stearoyl-2-oleoyl-sn-glycero-3-phosphocholine (SOPC) lipids at an electrified 1,2-dichloroethane/water interface is studied with X-ray reflectivity and interfacial tension. Measurements over a range of electric potential differences, -150 to +130 mV, that encompass the range of typical biomembrane potentials demonstrate a nearly constant and stable structure whose lipid interfacial density is comparable to that found in other biomimetic membrane systems. Measurements at higher positive potentials, up to 330 mV, illustrate a monotonic decrease in the lipid interfacial density and accompanying variations in the interfacial configuration of the lipid. Molecular dynamics simulations, designed to mimic the experimental conditions, show that the measured changes in lipid configuration are due primarily to the variation in area per lipid with increasing applied electric field. Rotation of the SOPC dipole moment by the torque from the applied electric field appears to be negligible, except at the highest measured potentials. The simulations confirm in atomistic detail the measured potential-dependent characteristics of SOPC monolayers. Our hybrid study sheds light on phospholipid monolayer stability under different membrane potentials, which is important for understanding membrane processes. This study also illustrates the use of X-ray surface scattering to probe the ordering of surfactant monolayers at an electrified aqueous-organic liquid-liquid interface.

  12. Self-assembly of amphiphilic molecules in organic liquids

    NASA Astrophysics Data System (ADS)

    Tung, Shih-Huang

    2007-12-01

    Amphiphilic molecules are well-known for their ability to self-assemble in water to form structures such as micelles and vesicles. In comparison, much less is known about amphiphilic self-assembly in nonpolar organic liquids. Such "reverse" self assembly can produce many of the counterparts to structures found in water. In this dissertation, we focus on the formation and dynamics of such reverse structures. We seek to obtain fundamental insight into the driving forces for reverse self-assembly processes. Three specific types of reverse structures are studied: (a) reverse wormlike micelles, i.e., long, flexible micellar chains; (b) reverse vesicles, i.e., hollow containers enclosed by reverse bilayers; and (c) organogel networks. While our focus is on the fundamentals, we note that reverse structures can be useful in a variety of applications ranging from drug delivery, controlled release, hosts for enzymatic reactions, and templates for nanomaterials synthesis. In the first part of this study, we describe a new route for forming reverse wormlike micelles in nonpolar organic liquids. This route involves the addition of trace amounts of a bile salt to solutions of the phospholipid, lecithin. We show that bile salts, due to their unique "facially amphiphilic" structure, can promote the aggregation of lecithin molecules into these reverse micellar chains. The resulting samples are viscoelastic and show interesting rheological properties. Unusual trends are seen in the temperature dependence of their rheology, which indicates the importance of hydrogen-bonding interactions in the formation of these micelles. Another remarkable feature of their rheology is the presence of strain-stiffening, where the material becomes stiffer at high deformations. Strain-stiffening has been seen before for elastic gels of biopolymers; here, we demonstrate the same properties for viscoelastic micellar solutions. The second reverse aggregate we deal with is the reverse vesicle. We present a

  13. Surface Tension of Organic Liquids Using the OPLS/AA Force Field.

    PubMed

    Zubillaga, Rafael A; Labastida, Ariana; Cruz, Bibiana; Martínez, Juan Carlos; Sánchez, Enrique; Alejandre, José

    2013-03-12

    Molecular dynamics simulations are performed to obtain the surface tension of 61 organic liquids using the OPLS/AA (all-atom optimized potential for liquid simulations). The force field parameters are the same as those recently used (Caleman et al. J. Chem. Theory Comput.2012, 8, 61) to determine several thermodynamic properties of 146 organic liquids. The correct evaluation of surface tension using slab simulations of liquids requires one to properly take into account the long-range interactions (Trukhymchuk and Alejandre J. Chem. Phys.1999, 111, 8510). In addition, the liquid density from slab simulations has to be the same as that obtained in liquid simulations at constant temperature and pressure. The new results of surface tensions from this work improve those reported by Caleman et al. The OPLS/AA force field gives good surface tensions compared with experimental data for most of the systems studied in this work, although it was developed to simulate liquids.

  14. Method and apparatus for the removal of bioconversion of constituents of organic liquids

    DOEpatents

    Scott, Timothy; Scott, Charles D.

    1994-01-01

    A method and apparatus for the removal or conversion of constituents from bulk organic liquids. A countercurrent biphasic bioreactor system is utilized to disperse and recoalesce a biocatalyst contained in the aqueous liquid phase into the organic liquid phase containing the constituent. Two transient, high-intensity electrical fields rupture the aqueous drops into a plurality of microdroplets and induce continuous coalescence and redispersion as the microdroplets travel through the organic phase, thus increasing surface area. As the aqueous microdroplets progress through the organic phase, the biocatalyst then reacts with the constituent to produce a product which is then removed from the bioreactor in the aqueous phase or retained in the organic phase. The organic liquid, now free of the original constituents, is ready for immediate use or further processing.

  15. Method and apparatus for the removal or bioconversion of constituents of organic liquids

    DOEpatents

    Scott, T.; Scott, C.D.

    1994-10-25

    A method and apparatus are disclosed for the removal or conversion of constituents from bulk organic liquids. A countercurrent biphasic bioreactor system is utilized to disperse and recoalesce a biocatalyst contained in the aqueous liquid phase into the organic liquid phase containing the constituent. Two transient, high-intensity electrical fields rupture the aqueous drops into a plurality of microdroplets and induce continuous coalescence and redispersion as the microdroplets travel through the organic phase, thus increasing surface area. As the aqueous microdroplets progress through the organic phase, the biocatalyst then reacts with the constituent to produce a product which is then removed from the bioreactor in the aqueous phase or retained in the organic phase. The organic liquid, now free of the original constituents, is ready for immediate use or further processing. 1 fig.

  16. Partition coefficients of organic compounds in new imidazolium based ionic liquids using inverse gas chromatography.

    PubMed

    Revelli, Anne-Laure; Mutelet, Fabrice; Jaubert, Jean-Noël

    2009-06-05

    Partition coefficients of organic compounds in four ionic liquids: 1-ethanol-3-methylimidazolium tetrafluoroborate, 1-ethanol-3-methylimidazolium hexafluorophosphate, 1,3-dimethylimidazolium dimethylphosphate and 1-ethyl-3-methylimidazolium diethylphosphate were measured using inverse gas chromatography from 303.3 to 332.55K. The influence of gas-liquid and gas-solid interfacial adsorption of different solutes on ionic liquids was also studied. Most of the polar solutes were retained largely by partition while light hydrocarbons were retained predominantly by interfacial adsorption on the ionic liquids studied in this work. The solvation characteristics of the ionic liquids were evaluated using the Abraham solvation parameter model.

  17. [Emergent retention of organic liquid by modified bentonites: property and mechanism].

    PubMed

    Li, Yu; Liu, Xian-Jun; Zhang, Xing-Wang; Lei, Le-Cheng

    2012-03-01

    In this study, the property and mechanism of modified bentonites synthesized by long chain quaternary ammonium compounds which would be used in the emergent retention of typical organic liquid (benzene, chlorobenzene, nitrobenzene and diesel) were investigated and a pilot-scale simulation experiment was conducted. The unit retention capacity of modified bentonites for organic liquid (2.83-9.01 g x g(-1)) was much higher than that of conventional retention agents (0.28-1.17 g x g(-1)). The property and amount of the surfactants used and viscosity of organic liquid had a significant influence on the retention capacity of modified bentonites for the organic liquid, for example, the bentonites modified by cetyltrimethylammonium (CTMAB) with an adding quantity of 100% CEC showed the highest efficiency in the retention of organic liquid. In the simulation experiment, organic liquid could be retained effectively within 30 min by emergent retention device with modified bentonites and the retention efficiency might reach positively up to 90%. Results indicated that modifications using surfactants could enhance the hydrophobicity and interlayer space of the modified bentonites and make their retention capacities for organic liquid improved.

  18. A reversible zwitterionic SO 2 -binding organic liquid

    SciTech Connect

    Heldebrant, David J.; Koech, Phillip K.; Yonker, Clement R.

    2010-01-01

    Propanol functionalized tetramethylguanidine (TMG-Pr-OH) is a liquid that reacts with CO2 to form a viscous Zwitterionic liquid that contains 20.8% by weight CO2. CO2 is chemically bound to the alcohol as an alkylcarbonate, which is then stabilized by hydrogen bonding to the guanidine component. The Zwitterionic liquid can be reverted to its non-ionic form by thermally stripping the CO2 at temperatures near 100 °C.

  19. Characterizing the Impact of Enhanced Solubilization Reagents on Organic-Liquid Morphology and Organic-Liquid/Water Interfacial Area Using Synchrotron X-ray Microtomography

    NASA Astrophysics Data System (ADS)

    Narter, M.; Brusseau, M.

    2010-12-01

    A primary goal of enhanced solubilization reagents is to increase contaminant mass transfer into the aqueous phase in order to achieve faster and more efficient mass removal from the subsurface. The rate of mass transfer depends on the degree of contact between the aqueous phase and the contaminant, and thus is dependent upon the interfacial area between the two phases. It is therefore important to understand the impact of enhanced solubilization reagents on organic-liquid distribution and morphology. This was accomplished using synchrotron X-ray microtomography to examine entrapped organic liquid in a natural porous medium. Polyoxyethylene Sorbitan Monooleate (tween 80), hydroxypropyl-β-cyclodextrin (HPCD), sodium dodecyl sulfate (SDS), and ethanol were used as the solubilization agents. Tetrachloroethene (PCE) was used as the entrapped organic immiscible liquid. Microtomography images were collected prior to and after successive floods with three concentrations of each reagent. The results were compared to those obtained from equivalent experiments conducted with water flooding.

  20. Nanoscale organization in piperidinium-based room temperature ionic liquids

    NASA Astrophysics Data System (ADS)

    Triolo, Alessandro; Russina, Olga; Fazio, Barbara; Appetecchi, Giovanni Battista; Carewska, Maria; Passerini, Stefano

    2009-04-01

    Here we report on the complex nature of the phase diagram of N-alkyl-N-methylpiperidinium bis(trifluoromethanesulfonyl)imide ionic liquids using several complementary techniques and on their structural order in the molten state using small-wide angle x-ray scattering. The latter study indicates that the piperidinium aliphatic alkyl chains tend to aggregate, forming alkyl domains embedded into polar regions, similar to what we recently highlighted in the case of other ionic liquids.

  1. Controlling the Spatial Organization of Liquid Crystalline Nanoparticles by Composition of the Organic Grafting Layer.

    PubMed

    Wójcik, Michał M; Olesińska, Magdalena; Sawczyk, Michał; Mieczkowski, Józef; Górecka, Ewa

    2015-07-06

    Understanding how the spatial ordering of liquid crystalline nanoparticles can be controlled by different factors is of great importance in the further development of their photonic applications. In this paper, we report a new key parameter to control the mesogenic behavior of gold nanoparticles modified by rodlike thiols. An efficient method to control the spatial arrangement of hybrid nanoparticles in a condensed state is developed by changing the composition of the mesogenic grafting layer on the surface of the nanoparticles. The composition can be tuned by different conditions of the ligand exchange reaction. The thermal and optical behavior of the mesogenic and promesogenic ligands were investigated by using differential scanning calorimetry (DSC) and hot-stage polarized optical microscopy. The chemical structure of the synthesized hybrid nanoparticles was characterized by (1) H NMR spectroscopy, thermogravimetric analysis (TGA), XPS, and elemental analysis, whereas the superstructures were examined by small-angle X-ray diffraction (SAXSRD) analysis. Structural studies showed that the organic sublayer made of mesogenic ligands is denser with an increasing the average ligand number, thereby separating the nanoparticles in the liquid crystalline phases, which changes the parameters of these phases. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY OF SELECTED ORGANIC PEROXIDES WITH OXIDATIVE AMPEROMETRIC DETECTION

    EPA Science Inventory

    Reversed-phase high-performance liquid chromatography with oxidative amperometric detection was optimized for the determination of several organic peroxides in drinking water under ideal conditions.The determinations were performed under isocratic conditions using acetonitrile an...

  3. HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY OF SELECTED ORGANIC PEROXIDES WITH OXIDATIVE AMPEROMETRIC DETECTION

    EPA Science Inventory

    Reversed-phase high-performance liquid chromatography with oxidative amperometric detection was optimized for the determination of several organic peroxides in drinking water under ideal conditions.The determinations were performed under isocratic conditions using acetonitrile an...

  4. Role of Aerosol Liquid Water in Secondary Organic Aerosol Formation from Volatile Organic Compounds.

    PubMed

    Faust, Jennifer A; Wong, Jenny P S; Lee, Alex K Y; Abbatt, Jonathan P D

    2017-02-07

    A key mechanism for atmospheric secondary organic aerosol (SOA) formation occurs when oxidation products of volatile organic compounds condense onto pre-existing particles. Here, we examine effects of aerosol liquid water (ALW) on relative SOA yield and composition from α-pinene ozonolysis and the photooxidation of toluene and acetylene by OH. Reactions were conducted in a room-temperature flow tube under low-NOx conditions in the presence of equivalent loadings of deliquesced (∼20 μg m(-3) ALW) or effloresced (∼0.2 μg m(-3) ALW) ammonium sulfate seeds at exactly the same relative humidity (RH = 70%) and state of wall conditioning. We found 13% and 19% enhancements in relative SOA yield for the α-pinene and toluene systems, respectively, when seeds were deliquesced rather than effloresced. The relative yield doubled in the acetylene system, and this enhancement was partially reversible upon drying the prepared SOA, which reduced the yield by 40% within a time scale of seconds. We attribute the high relative yield of acetylene SOA on deliquesced seeds to aqueous partitioning and particle-phase reactions of the photooxidation product glyoxal. The observed range of relative yields for α-pinene, toluene, and acetylene SOA on deliquesced and effloresced seeds suggests that ALW plays a complicated, system-dependent role in SOA formation.

  5. [Studies on the liquid-liquid extraction behaviour of Co(II) and Ni(II) without organic solvents].

    PubMed

    Zhang, Z; Deng, F; Shi, Y

    1998-06-01

    In PEG-Eriochrome cyanine R-(NH4)2SO4 system the liquid-liquid extraction behaviour of Co(II) and Ni(II) without organic solvents was investigated. We found that Ni(II) was almost extracted by PEG phase while Co(II) was not extracted in the water solutions of NaAc-HAc (pH=5) and (NH4)2SO4. Thus Co(II) was quantitatively separated from mixed solutions of Ni(II) and Co(II) ions.

  6. Using FT-IR spectroscopy to measure charge organization in ionic liquids.

    PubMed

    Burba, Christopher M; Janzen, Jonathan; Butson, Eric D; Coltrain, Gage L

    2013-07-25

    A major goal in the field of ionic liquids is correlating transport property trends with the underlying liquid structure of the compounds, such as the degree of charge organization among the constituent ions. Traditional techniques for experimentally assessing charge organization are specialized and not readily available for routine measurements. This represents a significant roadblock in elucidating these correlations. We use a combination of transmission and polarized-ATR infrared spectroscopy to measure the degree of charge organization for ionic liquids. The technique is illustrated with a family of 1-alkyl-3-methylimidazolium trifluoromethanesulfonate ionic liquids at 30 °C. As expected, the amount of charge organization decreases as the alkyl side chain is lengthened, highlighting the important role of short-range repulsive interactions in defining quasilattice structure. Inherent limitations of the method are identified and discussed. The quantitative measurements of charge organization are then correlated with trends in the transport properties of the compounds to highlight the relationship between charge and momentum transport and the underlying liquid structure. Most research laboratories possess infrared spectrometers capable of conducting these measurements; thus, the proposed method may represent a cost-effective solution for routinely measuring charge organization in ionic liquids.

  7. Using FT-IR Spectroscopy to Measure Charge Organization in Ionic Liquids

    PubMed Central

    Burba, Christopher M.; Janzen, Jonathan; Butson, Eric D.; Coltrain, Gage L.

    2013-01-01

    A major goal in the field of ionic liquids is correlating transport property trends with the underlying liquid structure of the compounds, such as the degree of charge organization among the constituent ions. Traditional techniques for experimentally assessing charge organization are specialized and not readily available for routine measurements. This represents a significant roadblock in elucidating these correlations. We use a combination of transmission and polarized-ATR infrared spectroscopy to measure the degree of charge organization for ionic liquids. The technique is illustrated with a family of 1-alkyl-3-methylimidazolium trifluoromethansulfonate ionic liquids at 30°C. As expected, the amount of charge organization decreases as the alkyl side chain is lengthened, highlighting the important role of short-range repulsive interactions in defining quasilattice structure. Inherent limitations of the method are identified and discussed. The quantitative measurements of charge organization are then correlated with trends in the transport properties of the compounds to highlight the relationship between charge and momentum transport and the underlying liquid structure. Most research laboratories possess infrared spectrometers capable of conducting these measurements, thus, the proposed method may represent a cost-effective solution for routinely measuring charge organization in ionic liquids. PMID:23781877

  8. Nanoscale investigations on interchain organization in thin films of polymer-liquid crystal blend

    NASA Astrophysics Data System (ADS)

    Villeneuve-Faure, C.; Le Borgne, D.; Ventalon, V.; Seguy, I.; Moineau-Chane Ching, K. I.; Bedel-Pereira, E.

    2017-07-01

    Optimized nanomorphology in organic thin active layers is crucial for good performance in organic solar cells. However, the relation between morphology and electronic properties at nanoscale remains not completely understood. Here, we study the effect of film thickness and temperature annealing on the ordering of poly(3-hexylthiophene) chains when the polymer is blended with a columnar liquid crystalline molecule. Electronic absorption, atomic force microscopy measurements, and Raman spectroscopy show that morphology and chain ordering of the blend depend on the film thickness. We highlight the benefit of using a liquid crystal in organic blends, opening the way to use simple processing methods for the fabrication of organic electronic devices.

  9. Chemical reactions of metal powders with organic and inorganic liquids during ball milling

    NASA Technical Reports Server (NTRS)

    Arias, A.

    1975-01-01

    Chromium and/or nickel powders were milled in metal chlorides and in organic liquids representative of various functional groups. The powders always reacted with the liquid and became contaminated with elements from them. The milled powders had specific surface areas ranging from 0.14 to 37 sq m/g, and the total contamination with elements from the milling liquid ranged from 0.01 to 56 weight percent. Compounds resulting from substitution, addition, or elimination reactions formed in or from the milling liquid.

  10. Modeling the gas-particle partitioning of secondary organic aerosol: the importance of liquid-liquid phase separation

    NASA Astrophysics Data System (ADS)

    Zuend, A.; Seinfeld, J. H.

    2012-05-01

    The partitioning of semivolatile organic compounds between the gas phase and aerosol particles is an important source of secondary organic aerosol (SOA). Gas-particle partitioning of organic and inorganic species is influenced by the physical state and water content of aerosols, and therefore ambient relative humidity (RH), as well as temperature and organic loading levels. We introduce a novel combination of the thermodynamic models AIOMFAC (for liquid mixture non-ideality) and EVAPORATION (for pure compound vapor pressures) with oxidation product information from the Master Chemical Mechanism (MCM) for the computation of gas-particle partitioning of organic compounds and water. The presence and impact of a liquid-liquid phase separation in the condensed phase is calculated as a function of variations in relative humidity, organic loading levels, and associated changes in aerosol composition. We show that a complex system of water, ammonium sulfate, and SOA from the ozonolysis of α-pinene exhibits liquid-liquid phase separation over a wide range of relative humidities (simulated from 30% to 99% RH). Since fully coupled phase separation and gas-particle partitioning calculations are computationally expensive, several simplified model approaches are tested with regard to computational costs and accuracy of predictions compared to the benchmark calculation. It is shown that forcing a liquid one-phase aerosol with or without consideration of non-ideal mixing bears the potential for vastly incorrect partitioning predictions. Assuming an ideal mixture leads to substantial overestimation of the particulate organic mass, by more than 100% at RH values of 80% and by more than 200% at RH values of 95%. Moreover, the simplified one-phase cases stress two key points for accurate gas-particle partitioning calculations: (1) non-ideality in the condensed phase needs to be considered and (2) liquid-liquid phase separation is a consequence of considerable deviations from ideal

  11. Modeling the gas-particle partitioning of secondary organic aerosol: the importance of liquid-liquid phase separation

    NASA Astrophysics Data System (ADS)

    Zuend, A.; Seinfeld, J. H.

    2012-01-01

    The partitioning of semivolatile organic compounds between the gas phase and aerosol particles is an important source of secondary organic aerosol (SOA). Gas-particle partitioning of organic and inorganic species is influenced by the physical state and water content of aerosols, and therefore ambient relative humidity (RH), as well as temperature and organic loading levels. We introduce a novel combination of the thermodynamic models AIOMFAC (for liquid mixture non-ideality) and EVAPORATION (for pure compound vapor pressures) with oxidation product information from the Master Chemical Mechanism (MCM) for the computation of gas-particle partitioning of organic compounds and water. The presence and impact of a liquid-liquid phase separation in the condensed phase is calculated as a function of variations in relative humidity, organic loading levels, and associated changes in aerosol composition. We show that a complex system of water, ammonium sulfate, and SOA from the ozonolysis of α-pinene exhibits liquid-liquid phase separation over a wide range of relative humidities (simulated from 30% to 99% RH). Since fully coupled phase separation and gas-particle partitioning calculations are computationally expensive, different simplified model approaches are tested with regards to computational costs and accuracy of predictions compared to the benchmark calculation. Both forcing a liquid one-phase aerosol considering non-ideal mixing or assuming an ideal mixture bear the potential for vastly incorrect partitioning predictions. Assuming an ideal mixture leads to substantial overestimation of the particulate organic mass, at high RH by more than 200%. Moreover, the simplified one-phase cases stress two key points for accurate gas-particle partitioning calculations: (1) non-ideality in the condensed phase needs to be considered and (2) liquid-liquid phase separation is a consequence of considerable deviations from ideal mixing in solutions containing inorganic ions and

  12. Vacuum Surface Science Meets Heterogeneous Catalysis: Dehydrogenation of a Liquid Organic Hydrogen Carrier in the Liquid State.

    PubMed

    Matsuda, Takashi; Taccardi, Nicola; Schwegler, Johannes; Wasserscheid, Peter; Steinrück, Hans-Peter; Maier, Florian

    2015-06-22

    Ultrahigh vacuum (UHV) surface science techniques are used to study the heterogeneous catalytic dehydrogenation of a liquid organic hydrogen carrier in its liquid state close to the conditions of real catalysis. For this purpose, perhydrocarbazole (PH), otherwise volatile under UHV, is covalently linked as functional group to an imidazolium cation, forming a non-volatile ionic liquid (IL). The catalysed dehydrogenation of the PH unit as a function of temperature is investigated for a Pt foil covered by a macroscopically thick PH-IL film and for Pd particles suspended in the PH-IL film, and for PH-IL on Au as inert support. X-ray photoelectron spectroscopy and thermal desorption spectroscopy allows us to follow in situ the catalysed transition of perhydrocarbazole to carbazole at technical reaction temperatures. The data demonstrate the crucial role of the Pt and Pd catalysts in order to shift the dehydrogenation temperature below the critical temperature of thermal decomposition.

  13. Development of dispersive liquid-liquid microextraction based on solidification of floating organic drop for the determination of trace nickel.

    PubMed

    Wang, Yukun; Zhang, Jingwen; Zhao, Bin; Du, Xin; Ma, Jingjun; Li, Jingci

    2011-12-01

    A liquid-phase microextraction technique was developed using dispersive liquid-liquid microextraction based on solidification of floating organic drop combined with flame atomic absorption spectrometry, for the extraction and determination of trace amounts of nickel in water samples. Microextraction efficiency factors, such as the type and volume of extraction and dispersive solvents, pH, extraction time, the chelating agent amount, and ionic strength, were investigated and optimized. Under optimum conditions, the calibration graph was linear in the range of 4.23-250 μg L(-1) with a detection limit of 1.27 μg L(-1). The relative standard deviation for ten replicate measurements of 10 and 100 μg L(-1) of nickel were 3.21% and 2.55%, respectively. The proposed method was assessed through the analysis of certified reference water or recovery experiments.

  14. Soft magnets from the self-organization of magnetic nanoparticles in twisted liquid crystals.

    PubMed

    Matt, Benjamin; Pondman, Kirsten M; Asshoff, Sarah J; Ten Haken, Bennie; Fleury, Benoit; Katsonis, Nathalie

    2014-11-10

    Organizing magnetic nanoparticles into long-range and dynamic assemblies would not only provide new insights into physical phenomena but also open opportunities for a wide spectrum of applications. In particular, a major challenge consists of the development of nanoparticle-based materials for which the remnant magnetization and coercive field can be controlled at room temperature. Our approach consists of promoting the self-organization of magnetic nanoparticles in liquid crystals (LCs). Using liquid crystals as organizing templates allows us to envision the design of tunable self-assemblies of magnetic nanoparticles, because liquid crystals are known to reorganize under a variety of external stimuli. Herein, we show that twisted liquid crystals can be used as efficient anisotropic templates for superparamagnetic nanoparticles and demonstrate the formation of hybrid soft magnets at room temperature. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

    NASA Astrophysics Data System (ADS)

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

    2016-08-01

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

  16. Method for monitoring the crystallization of an organic material from a liquid

    DOEpatents

    Asay, Blaine W.; Henson, Bryan F.; Sander, Robert K.; Robinson, Jeanne M.; Son, Steven F.; Dickson, Peter M.

    2004-10-05

    Method for monitoring the crystallization of at least one organic material from a liquid. According to the method, a liquid having at least one organic material capable of existing in at least one non-centrosymmetric phase is prepared. The liquid is interrogated with a laser beam at a chosen wavelength. As at least a portion of the at least one organic material crystallizes from the liquid, the intensity of any light scattered by the crystallized material at a wavelength equal to one-half the chosen wavelength of the interrogating laser beam is monitored. If the intensity of this scattered light, increases, then the crystals that form include at least one non-cetrosymmetric phase.

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

    PubMed

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

    2016-08-19

    Liquid-phase separations of similarly sized organic molecules using membranes is a major challenge for energy-intensive industrial separation processes. We created free-standing carbon molecular sieve membranes that translate the advantages of reverse osmosis for aqueous separations to the separation of organic liquids. Polymer precursors were cross-linked with a one-pot technique that protected the porous morphology of the membranes from thermally induced structural rearrangement during carbonization. Permeation studies using benzene derivatives whose kinetic diameters differ by less than an angstrom show kinetically selective organic liquid reverse osmosis. Ratios of single-component fluxes for para- and ortho-xylene exceeding 25 were observed and para- and ortho- liquid mixtures were efficiently separated, with an equimolar feed enriched to 81 mole % para-xylene, without phase change and at ambient temperature. Copyright © 2016, American Association for the Advancement of Science.

  18. Measurement and Estimation of Organic-Liquid/Water Interfacial Areas for Several Natural Porous Media

    SciTech Connect

    Brusseau, M.L.; Narter, M.; Schnaar, G.; Marble, J.

    2009-06-01

    The objective of this study was to quantitatively characterize the impact of porous-medium texture on interfacial area between immiscible organic liquid and water residing within natural porous media. Synchrotron X-ray microtomography was used to obtain high-resolution, three-dimensional images of solid and liquid phases in packed columns. The image data were processed to generate quantitative measurements of organic-liquid/water interfacial area and of organic-liquid blob sizes. Ten porous media, comprising a range of median grain sizes, grain-size distributions, and geochemical properties, were used to evaluate the impact of porous-medium texture on interfacial area. The results show that fluid-normalized specific interfacial area (A{sub f}) and maximum specific interfacial area (A{sub m}) correlate very well to inverse median grain diameter. These functionalities were shown to result from a linear relationship between effective organic-liquid blob diameter and median grain diameter. These results provide the basis for a simple method for estimating specific organic-liquid/water interfacial area as a function of fluid saturation for a given porous medium. The availability of a method for which the only parameter needed is the simple-to-measure median grain diameter should be of great utility for a variety of applications.

  19. Fluorescence decay-time constants in organic liquid scintillators.

    PubMed

    Marrodán Undagoitia, T; von Feilitzsch, F; Oberauer, L; Potzel, W; Ulrich, A; Winter, J; Wurm, M

    2009-04-01

    The fluorescence decay-time constants have been measured for several scintillator mixtures based on phenyl-o-xylylethane (PXE) and linear alkylbenzene (LAB) solvents. The resulting values are of relevance for the physics performance of the proposed large-volume liquid scintillator detector Low Energy Neutrino Astronomy (LENA). In particular, the impact of the measured values to the search for proton decay via p-->K(+)nu is evaluated in this work.

  20. Liquid crystalline tetrahedra and low-aspect-ratio organic materials

    NASA Astrophysics Data System (ADS)

    Pegenau, A.; Goering, P.; Diele, S.; Tschierske, C.

    1998-01-01

    3,4-Dialkoxybenzoates of pentaerythritol and structural related polyhydroxy compounds have been synthesized and investigated by polarizing microscopy, differential scanning calorimetry and some of them also by x-ray scattering. Despite the fact that these compounds are neither anisometric nor amphilphilic in a classical sense they can display columnar liquid-crystalline phases. It is proposed, that the segregation of the polar regions and the lipophilic alkyl chains into separate regions is mainly responsible for the formation of these mesophases.

  1. Fluorescence decay-time constants in organic liquid scintillators

    SciTech Connect

    Marrodan Undagoitia, T.; Feilitzsch, F. von; Oberauer, L.; Potzel, W.; Ulrich, A.; Winter, J.; Wurm, M.

    2009-04-15

    The fluorescence decay-time constants have been measured for several scintillator mixtures based on phenyl-o-xylylethane (PXE) and linear alkylbenzene (LAB) solvents. The resulting values are of relevance for the physics performance of the proposed large-volume liquid scintillator detector Low Energy Neutrino Astronomy (LENA). In particular, the impact of the measured values to the search for proton decay via p{yields}K{sup +}{nu} is evaluated in this work.

  2. Application of dispersive liquid-liquid-solidified floating organic drop microextraction and ETAAS for the preconcentration and determination of indium.

    PubMed

    Ashrafzadeh Afshar, Elham; Taher, Mohammad Ali; Fazelirad, Hamid; Naghizadeh, Matin

    2017-03-01

    A new, simple and efficient method, including dispersive liquid-liquid-solidified floating organic drop microextraction and then electrothermal atomic absorption spectrometry, has been developed for the preconcentration and determination of ultratrace amounts of indium. The method was applied to preconcentrate the indium-1-(2-pyridylazo)-2-naphthol complex in 25 μL 1-undecanol. The various factors affecting the extraction efficiency, such as pH, type and volume of extraction solvent, type and volume of disperser solvent, sample volume, ionic strength, and ligand concentration, were investigated and optimized. Under the optimum conditions, an enrichment factor of 62.5, precision of ±4.75%, a detection limit of 55.6 ng L(-1), and for the calibration graph a linear range of 96.0-3360 ng L(-1) were obtained. The method was used for the extraction and determination of indium in water and standard samples with satisfactory results. Graphical Abstract Preconcentration of indium ions via liquid-liquid-solidified floating organic drop microextraction method and determination by ETAAS.

  3. Tuning Correlations in Low-Dimensional Electron Systems: Fermi liquid versus non-Fermi-liquid behavior in organic conductors

    NASA Astrophysics Data System (ADS)

    Dressel, Martin

    2012-02-01

    While the electronic properties of cuprates can be modified by electron or hole doping, organic conductors provide the opportunity to tune the strength of electronic correlations more directly. Varying the bandwidth by (physical or chemical) pressure, the κ-phase BEDT-TTF compounds cross over from a Fermi liquid to a Mott insulator by increasing effective correlations. We systematically investigate the electronic transport properties in organic conductors by dc resistivity and optical measurements in order to extract the temperature and frequency-dependent scattering rate 1/τ= A(kBT)^2 + B(φ)^2. We find corresponding temperature and frequency ranges in which the parabolic behaviors are observed. For the first time, we can quantitatively relate the two prefactors (A/B=56) and their enhancement as correlations increase upon approaching the Mott transition. Conceptually low-dimensional organic conductors are also good candidates for quantum criticality because often an ordered state is located next to a metallic state when the system is tuned by pressure. Interestingly both are found, order in the spin as well as in the charge sector. Fermi-liquid behavior observed in the metallic state seems to be limited to certain regions of the phase diagram with non-Fermi-liquid properties evolving as the ordered phase is approached. It is not clear whether these deviations from Fermi liquid behavior are actually a signature of quantum criticality.[4pt] [1] M. Dressel, Quantum criticality in organic conductors? Fermi-liquid versus non-Fermi-liquid behavior, J. Phys.: Condens. Matter 23, 293201 (2011).[2] S. Yasin, M. Dumm, B. Salameh, P. Batail, C. M'ezi'ere and M. Dressel, Transport studies at the Mott transition of the two-dimensional organic metal κ-(BEDT-TTF)2Cu[N(CN)2]BrxCl1-x, Eur. Phys. J. B 79, 383 (2011).[3] M. Dumm, D. Faltermeier, N. Drichko and M. Dressel, Bandwidth-controlled Mott transition in κ-(BEDT-TTF)2Cu[N(CN)2]BrxCl1-x: Optical studies of correlated

  4. THERMODYNAMIC MODELING OF LIQUID AEROSOLS CONTAINING DISSOLVED ORGANICS AND ELECTROLYTES

    EPA Science Inventory

    Many tropospheric aerosols contain large fractions of soluble organic material, believed to derive from the oxidation of precursors such alpha-pinene. The chemical composition of aerosol organic matter is complex and not yet fully understood.

    The key properties of solu...

  5. THERMODYNAMIC MODELING OF LIQUID AEROSOLS CONTAINING DISSOLVED ORGANICS AND ELECTROLYTES

    EPA Science Inventory

    Many tropospheric aerosols contain large fractions of soluble organic material, believed to derive from the oxidation of precursors such alpha-pinene. The chemical composition of aerosol organic matter is complex and not yet fully understood.

    The key properties of solu...

  6. Anion-directed self-organization of thermotropic liquid crystalline materials containing a guanidinium moiety.

    PubMed

    Kim, Dongwoo; Jon, Sangyong; Lee, Hyung-Kun; Baek, Kangkyun; Oh, Nam-Keun; Zin, Wang-Cheol; Kim, Kimoon

    2005-11-28

    New wedge-shaped thermotropic liquid crystalline materials containing a guanidinium moiety at the apex organize into various supramolecular structures such as hexagonal columnar, rectangular columnar and Pm3n cubic mesophases depending on anions illustrating guest-directed self-organization in mesophases.

  7. Mixed organic compound-ionic liquid electrolytes for lithium battery electrolyte systems

    NASA Astrophysics Data System (ADS)

    Montanino, M.; Moreno, M.; Carewska, M.; Maresca, G.; Simonetti, E.; Lo Presti, R.; Alessandrini, F.; Appetecchi, G. B.

    2014-12-01

    The thermal, transport, rheological and flammability properties of electrolyte mixtures, proposed for safer lithium-ion battery systems, were investigated as a function of the mole composition. The blends were composed of a lithium salt (LiTFSI), organic solvents (namely EC, DEC) and an ionic liquid (PYR13TFSI). The main goal is to combine the fast ion transport properties of the organic compounds with the safe issues of the non-flammable and non-volatile ionic liquids. Preliminary tests in batteries have evidenced cycling performance approaching that observed in commercial organic electrolytes.

  8. Estimation of interfacial tension between organic liquid mixtures and water.

    PubMed

    Yoon, Hongkyu; Oostrom, Mart; Werth, Charles J

    2009-10-15

    Knowledge of IFT values for chemical mixtures helps guide the design and analysis of various processes, including NAPL remediation with surfactants or alcohol flushing, enhanced oil recovery, and chemical separation technologies, yet available literature values are sparse. A comprehensive comparison of thermodynamic and empirical models for estimating interfacial tension (IFT) of organic chemical mixtures with water is conducted, mainly focusing on chlorinated organic compounds for 14 ternary, three quaternary, and one quinary systems. Emphasis is placed on novel results for systems with three and four organic chemical compounds, and for systems with composite organic compounds like lard oil and mineral oil. Seven models are evaluated: the ideal and nonideal monolayer models (MLID and MLNID), the ideal and nonideal mutual solubility models (MSID and MSNID), an empirical model for ternary systems (EM), a linear mixing model based on mole fractions (LMMM), and a newly developed linear mixing model based on volume fractions of organic mixtures (LMMV) for higher order systems. The two ideal models (MLID and MSID) fit ternary systems of chlorinated organic compounds without surface active compounds relatively well. However, both ideal models did not perform well for the mixtures containing a surface active compound. However, for these systems, both the MLNID and MSNID models matched the IFT data well. It is shown that the MLNID model with a surface coverage value (0.00341 mmol/m2) obtained in this study can practically be used for chlorinated organic compounds. The LMMM results in poorer estimates of the IFT as the difference in IFT values of individual organic compounds in a mixture increases. The EM, with two fitting parameters, provided accurate results for all 14 ternarysystems including composite organic compounds. The new LMMV method for quaternary and higher component systems was successfully tested. This study shows that the LMMV may be able to be used for

  9. Estimation of Interfacial Tension between Organic Liquid Mixtures and Water

    SciTech Connect

    Yoon, Hongkyu; Oostrom, Martinus; Werth, Charles J.

    2009-10-15

    Knowledge of IFT values for chemical mixtures helps guide the design and analysis of various processes, including NAPL remediation with surfactants or alcohol flushing, enhanced oil recovery, and chemical separation technologies, yet available literature values are sparse. A comprehensive comparison of thermodynamic and empirical models for estimating interfacial tension (IFT) of organic chemical mixtures with water is conducted, mainly focusing on chlorinated organic compounds for 14 ternary, three quaternary, and one quinary systems. Emphasis is placed on novel results for systems with three and four organic chemical compounds, and for systems with composite organic compounds like lard oil and mineral oil. Seven models are evaluated: the ideal and nonideal monolayer models (MLID and MLNID), the ideal and nonideal mutual solubility models (MSID and MSNID), an empirical model for ternary systems (EM), a linear mixing model based on mole fractions (LMMM), and a newly developed linear mixing model based on volume fractions of organic mixtures (LMMV) for higher order systems. The two ideal models (MLID and MSID) fit ternary systems of chlorinated organic compounds without surface active compounds relatively well. However, both ideal models did not perform well for the mixtures containing a surface active compound. However, for these systems, both the MLNID and MSNID models matched the IFT data well. It is shown that the MLNID model with a surface coverage value (0.00341 mmol/m2) obtained in this study can practically be used for chlorinated organic compounds. The LMMM results in poorer estimates of the IFT as the difference in IFT values of individual organic compounds in a mixture increases. The EM, with two fitting parameters, provided accurate results for all 14 ternary systems including composite organic compounds. The new LMMV method for quaternary and higher component systems was successfully tested. This study shows that the LMMV may be able to be used for

  10. Underwater Spontaneous Pumpless Transportation of Nonpolar Organic Liquids on Extreme Wettability Patterns.

    PubMed

    Huang, Shuai; Song, Jinlong; Lu, Yao; Chen, Faze; Zheng, Huanxi; Yang, Xiaolong; Liu, Xin; Sun, Jing; Carmalt, Claire J; Parkin, Ivan P; Xu, Wenji

    2016-02-10

    Spontaneous pumpless transportation (SPT) of liquids has generated tremendous demands in microfluidic systems and advanced devices. However, the transportation of nonpolar organic liquids on open platforms underwater remains a challenge because most existing SPT systems are only designed for use in air. Here, we report a surface-tension-driven SPT system to transport various nonpolar organic liquids using underwater extreme wettability patterns. The patterns were fabricated with a wedge-shaped superoleophilic track on a superoleophobic background by combining CuCl2 etching, stearic acid modification, and mask-based nitrogen cold plasma treatment. Three types of underwater SPT processes-horizontal transport, tilted transport, and directional transport-were studied experimentally and theoretically. For horizontal SPT and tilted SPT, the capillary force was the main driving force, which depended on the wedge angle of the superoleophilic track. The excellent transportation ability of horizontal SPT of underwater liquid droplets was obtained at a wedge angle of 3-5°. The maximum moving height of organic liquids on the tilted SPT transport was obtained at an angle of 8°. For directional SPT, organic liquids did not drop off in the moving process because of the constraint imposed by surface tension, resulting in the sustained directional transport with long distances and complex trajectories.

  11. Sorption of vapors of some organic liquids on soil humic acid and its relation to partitioning of organic compounds in soil organic matter

    USGS Publications Warehouse

    Chlou, G.T.; Kile, D.E.; Malcolm, R.L.

    1988-01-01

    Vapor sorption of water, ethanol, benzene, hexane, carbon tetrachloride, 1,1,1-trichloroethane, trichloroethylene, tetrachloroethylene, and 1,2-dibromoethane on (Sanhedron) soil humic acid has been determined at room temperature. Isotherms for all organic liquids are highly linear over a wide range of relative pressure (P/P??), characteristic of the partitioning (dissolution) of the organic compounds in soil humic acid. Polar liquids exhibit markedly greater sorption capacities on soil humic acid than relatively nonpolar liquids, in keeping with the polar nature of the soil humic acid as a partition medium. The limiting sorption (partition) capacities of relatively non-polar liquids are remarkably similar when expressed in terms of volumes per unit weight of soil humic acid. The soil humic acid is found to be about half as effective as soil organic matter in sorption of relatively nonpolar organic compounds. The nearly constant limiting sorption capacity for nonpolar organic liquids with soil humic acid on a volume-to-weight basis and its efficiency in sorption relative to soil organic matter provide a basis for predicting the approximate sorption (partition) coefficients of similar compounds in uptake by soil in aqueous systems.

  12. Analysis of a gas-liquid film plasma reactor for organic compound oxidation.

    PubMed

    Hsieh, Kevin; Wang, Huijuan; Locke, Bruce R

    2016-11-05

    A pulsed electrical discharge plasma formed in a tubular reactor with flowing argon carrier gas and a liquid water film was analyzed using methylene blue as a liquid phase hydroxyl radical scavenger and simultaneous measurements of hydrogen peroxide formation. The effects of liquid flow rate, liquid conductivity, concentration of dye, and the addition of ferrous ion on dye decoloration and degradation were determined. Higher liquid flow rates and concentrations of dye resulted in less decoloration percentages and hydrogen peroxide formation due to initial liquid conductivity effects and lower residence times in the reactor. The highest decoloration energy yield of dye found in these studies was 5.2g/kWh when using the higher liquid flow rate and adding the catalyst. The non-homogeneous nature of the plasma discharge favors the production of hydrogen peroxide in the plasma-liquid interface over the chemical oxidation of the organic in the bulk liquid phase and post-plasma reactions with the Fenton catalyst lead to complete utilization of the plasma-formed hydrogen peroxide. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. LABORATORY INVESTIGATION OF RESIDUAL LIQUID ORGANICS FROM SPILLS, LEAKS, AND THE DISPOSAL OF HAZARDOUS WASTES IN GROUNDWATER

    EPA Science Inventory

    Organic liquids that are essentially immiscible with water migrate through the subsurface under the influence of capillary, viscous, and buoyancy forces. These liquids originate from the improper disposal of hazardous wastes, and the spills and leaks of petroleum hydrocarbons a...

  14. LABORATORY INVESTIGATION OF RESIDUAL LIQUID ORGANICS FROM SPILLS, LEAKS, AND THE DISPOSAL OF HAZARDOUS WASTES IN GROUNDWATER

    EPA Science Inventory

    Organic liquids that are essentially immiscible with water migrate through the subsurface under the influence of capillary, viscous, and buoyancy forces. These liquids originate from the improper disposal of hazardous wastes, and the spills and leaks of petroleum hydrocarbons a...

  15. A high liquid yield process for retorting various organic materials including oil shale

    DOEpatents

    Coburn, T.T.

    1988-07-26

    This invention is a continuous retorting process for various high molecular weight organic materials, including oil shale, that yields an enhanced output of liquid product. The organic material, mineral matter, and an acidic catalyst, that appreciably adsorbs alkenes on surface sites at prescribed temperatures, are mixed and introduced into a pyrolyzer. A circulating stream of olefin enriched pyrolysis gas is continuously swept through the organic material and catalyst, whereupon, as the result of pyrolysis, the enhanced liquid product output is provided. Mixed spent organic material, mineral matter, and cool catalyst are continuously withdrawn from the pyrolyzer. Combustion of the spent organic material and mineral matter serves to reheat the catalyst. Olefin depleted pyrolysis gas, from the pyrolyzer, is enriched in olefins and recycled into the pyrolyzer. The reheated acidic catalyst is separated from the mineral matter and again mixed with fresh organic material, to maintain the continuously cyclic process. 2 figs.

  16. High liquid yield process for retorting various organic materials including oil shale

    DOEpatents

    Coburn, Thomas T.

    1990-01-01

    This invention is a continuous retorting process for various high molecular weight organic materials, including oil shale, that yields an enhanced output of liquid product. The organic material, mineral matter, and an acidic catalyst, that appreciably adsorbs alkenes on surface sites at prescribed temperatures, are mixed and introduced into a pyrolyzer. A circulating stream of olefin enriched pyrolysis gas is continuously swept through the organic material and catalyst, whereupon, as the result of pyrolysis, the enhanced liquid product output is provided. Mixed spent organic material, mineral matter, and cool catalyst are continuously withdrawn from the pyrolyzer. Combustion of the spent organic material and mineral matter serves to reheat the catalyst. Olefin depleted pyrolysis gas, from the pyrolyzer, is enriched in olefins and recycled into the pyrolyzer. The reheated acidic catalyst is separated from the mineral matter and again mixed with fresh organic material, to maintain the continuously cyclic process.

  17. Impact of Organic-Liquid Distribution and Flow-Field Heterogeneity on Reductions in Mass Flux

    SciTech Connect

    Difilippo, Erica L.; Carroll, Kenneth C.; Brusseau, Mark L.

    2010-06-07

    A series of flow-cell experiments was conducted to investigate the impact of organic-liquid distribution and flow-field heterogeneity on the relationship between source-zone mass removal and reductions in contaminant mass flux from the source zone. Changes in source-zone architecture were quantified using image analysis, allowing explicit examination of their impact on the mass-flux-reduction/mass-removal behavior. The results showed that there was minimal reduction in mass flux until a large fraction of mass was removed for systems wherein organic liquid was present solely as residual saturation in regions that were hydraulically accessible. Conversely, significant reductions in mass flux occurred with relatively minimal mass removal for systems wherein organic liquid was present at both residual and higher saturations. The latter systems exhibited multi-step mass-flux-reduction/mass-removal behavior, and characterization of the organic-liquid saturation distribution throughout flushing allowed identification of the cause of the nonideal behavior. The age of the source zone (time from initial emplacement to time of initial characterization) significantly influenced the observed mass-flux-reduction/mass-removal behavior. The results of this study illustrate the impact of both organic-liquid distribution and flow-field heterogeneity on mass-removal and mass-flux processes.

  18. Sample preparation of organic liquid for off-site analysis of chemical weapons convention related compounds.

    PubMed

    Pardasani, Deepak; Palit, Meehir; Gupta, A K; Shakya, Purushottam; Sekhar, K; Dubey, D K

    2005-02-15

    Off-site analysis of chemical warfare agents (CWAs) and related compounds plays a key role in the verification program of the Chemical Weapons Convention (CWC). The analysis results, aiming toward unambiguous identication of compounds, depend on the type of sample preparation method. Development of milder sample preparation methods, which offer good recoveries and do not alter the structure of analytes, is highly desirable. Organic liquid with high hydrocarbon background is a frequently encountered challenge in off-site analysis and in official proficiency tests conducted by OPCW. Sample cleanup procedures, namely, solvent exchange followed by cooling and liquid-liquid extraction were studied to eliminate the hydrocarbons from organic liquid. Acetonitrile, a polar aprotic solvent, was effectively used to remove the background in both methods, and recoveries of spiked CWAs by the two techniques were between 69 and 99%.

  19. Liquid drop technique for generation of organic glass and metal shells

    NASA Astrophysics Data System (ADS)

    Hendricks, C. D.

    1982-03-01

    It was found that liquid drop techniques are very useful in several diverse areas. For producing very uniform metallic, organic, inorganic and, on particular, glassy shells, the liquid jet method is the most reproducible and exceptionally useful of all the techniques studied. The technique of capillary wave synchronization of the break-up of single and multiple component jets was utilized to produce uniform sized liquid drops and solid particles, and hollow liquid and solid shells. The technique was also used to encapsulate a number of liquids in impermeable spherical shells. Highly uniform glass shells were made by generating uniform drops of glass forming materials in an aqueous solution, subsequently evaporating the water, and then fusing and blowing the remaining solids in a high temperature vertical tube furnace. Experimental results are presented and the critical problems in further research in this field are discussed.

  20. Liquid drop technique for generation of organic glass and metal shells

    NASA Technical Reports Server (NTRS)

    Hendricks, C. D.

    1982-01-01

    It was found that liquid drop techniques are very useful in several diverse areas. For producing very uniform metallic, organic, inorganic and, on particular, glassy shells, the liquid jet method is the most reproducible and exceptionally useful of all the techniques studied. The technique of capillary wave synchronization of the break-up of single and multiple component jets was utilized to produce uniform sized liquid drops and solid particles, and hollow liquid and solid shells. The technique was also used to encapsulate a number of liquids in impermeable spherical shells. Highly uniform glass shells were made by generating uniform drops of glass forming materials in an aqueous solution, subsequently evaporating the water, and then fusing and blowing the remaining solids in a high temperature vertical tube furnace. Experimental results are presented and the critical problems in further research in this field are discussed.

  1. Microbial consortium role in processing liquid waste of vegetables in Keputran Market Surabaya as organic liquid fertilizer ferti-plus

    NASA Astrophysics Data System (ADS)

    Rizqi, Fauziah; Supriyanto, Agus; Lestari, Intan; Lita Indri D., L.; Elmi Irmayanti, A.; Rahmaniyah, Fadilatur

    2016-03-01

    Many activities in this market is directly proportional to increase production of vegetables waste, especially surabaya. Therefore, in this study aims to utilize liquid waste of vegetables into liquid organic fertilizer by mixing microbial consorsium. The microbial consorsium consist of Azotobacter chrococcum, Azospirillum brasilense, Rhizobium leguminosarum, Bacillus subtilis, Bacillus megaterium, Pseudomonas putida, and Pseudomonas fluorescens. Ttreatment of microbial concentrations (5%, 10%, 15%) and the length of the incubation period (7 days, 14 days, 21 days) used in this research. The parameters used are: C/N ratio, levels of CNP, and BOD value. This study uses a standard organic fertilizer value according SNI19-7030-2004, The results show the value of C/N ratio comply with the ISO standards. C levels showed an increase during the incubation period but not compare with standards. N levels that compare with standards are microbial treatment in all group concentration except control group with an incubation period of 21 days is > 7. P levels compare with the existing standards in the group of microbe concentration of 10% and 15% during the incubation period. The value of the initial BOD liquid waste of vegetable is 790.25 mg / L, this value indicates that the waste should not go into the water body. Accordingly, the results of this study can not be used as a liquid organic fertilizer, but potentially if it is used as a natural career or build natural soil. The Building natural soil is defined as the natural ingredients that can be used to improve soil properties.

  2. Membrane permeation process for dehydration of organic liquid mixtures using sulfonated ion-exchange polyalkene membranes

    DOEpatents

    Cabasso, Israel; Korngold, Emmanuel

    1988-01-01

    A membrane permeation process for dehydrating a mixture of organic liquids, such as alcohols or close boiling, heat sensitive mixtures. The process comprises causing a component of the mixture to selectively sorb into one side of sulfonated ion-exchange polyalkene (e.g., polyethylene) membranes and selectively diffuse or flow therethrough, and then desorbing the component into a gas or liquid phase on the other side of the membranes.

  3. Mesoscopic structural organization in triphilic room temperature ionic liquids.

    PubMed

    Russina, Olga; Lo Celso, Fabrizio; Di Michiel, Marco; Passerini, Stefano; Appetecchi, Giovanni Battista; Castiglione, Franca; Mele, Andrea; Caminiti, Ruggero; Triolo, Alessandro

    2013-01-01

    Room temperature ionic liquids are one of the most exciting classes of materials in the last decade. The interest for these low melting, ionic compounds stems from both their technological impact and the stimulating plethora of structural and dynamic peculiarities in the mesoscopic space-time scales. It is nowadays well-established that they are characterised by an enhanced degree of mesoscopic order originating from their inherent amphiphilicity. In this contribution we highlight the existence of a further degree of mesoscopic complexity when dealing with RTILs bearing a medium length fluorous tail: such triphilic materials (they simultaneously contain polar, hydrophobic and fluorophilic moieties that mutually segregate from each other) turn out to be highly structurally compartmentalised at the mesoscopic level, thus paving the way to new smart applications for this new class of RTILs.

  4. Direct Capture of Organic Acids From Fermentation Media Using Ionic Liquids

    SciTech Connect

    Klasson, K.T.

    2004-11-03

    Several ionic liquids have been investigated for the extraction of organic acids from fermentation broth. Partitioning of representative organic acids (lactic, acetic, and succinic) between aqueous solution and nine hydrophobic ionic liquids was measured. The extraction efficiencies were strongly dependent on pH of the aqueous phase. Distribution coefficient was very good (approximately 60) at low succinic acid concentrations for one of the ionic liquids (trihexyltetradecylphosphonium methanesulfonate) at neutral pH. However, this ionic liquid had to be diluted with nonanol due to its high viscosity in order to be useful. A diluent (trioctylamine) was also added to this mixture. The results suggest that an extraction system based on ionic liquids may be feasible for succinic acid recovery from fermentation broth and that two ideal extraction stages are needed to reduce the concentration from 33 g/L to 1 g/L of succinic acid. Further studies are needed to evaluate other issues related to practical applications, including ionic liquid loss in the process, toxicity effects of ionic liquids during simultaneous fermentation and extractions.

  5. Investigation of Organic Compound Reactivity in Liquid and Frozen Aqueous Systems Using Relative Rate Experiments

    NASA Astrophysics Data System (ADS)

    Kurek, L.; Grannas, A. M.

    2012-12-01

    Previous studies have shown that snow and ice are highly reactive media where photochemical reactions occur. These reactions can have important consequences for the environment, including the production of organic compounds, halogens and nitrogen oxides that impact surface boundary layer chemistry. Laboratory-based studies have shown that the nature of the sample and the physical location of solutes play a large role in determining the reactivity of a particular compound. During the freezing of aqueous solutions, most solute molecules become excluded from the ice crystal lattice, increasing their apparent concentrations as they accumulate in liquid-like layers, micropockets, and microveins within the ice (freeze-concentration effect). In an effort to better understand how the physicochemical properties of solutes may impact reactivity in frozen solutions, we have examined the relative reaction rates of various organic compounds with hydroxyl radical in both liquid and frozen conditions. Solutions containing two target organic compounds and hydrogen peroxide were made in liquid and frozen phases, and then irradiated using a Q-Panel 340 lamp to simulate natural sunlight. Relative rates of reaction were then obtained for the two compounds in both liquid and ice conditions. In most cases the reactions proceeded more quickly in liquid samples, and the relative rates of reaction were different in liquid and frozen conditions. We will discuss the potential role of a compound's physicochemical properties and the influence of the physical nature of the sample with respect to observed reactivity differences.

  6. Methods for calculation of engineering parameters for gas separation. [vapor pressure and solubility of gases in organic liquids

    NASA Technical Reports Server (NTRS)

    Lawson, D. D.

    1979-01-01

    A group additivity method is generated which allows estimation, from the structural formulas alone, of the energy of vaporization and the molar volume at 25 C of many nonpolar organic liquids. Using these two parameters and appropriate thermodynamic relations, the vapor pressure of the liquid phase and the solubility of various gases in nonpolar organic liquids are predicted. It is also possible to use the data to evaluate organic and some inorganic liquids for use in gas separation stages or liquids as heat exchange fluids in prospective thermochemical cycles for hydrogen production.

  7. Modes of self-organization of diluted bubbly liquids in acoustic fields: One-dimensional theory.

    PubMed

    Gumerov, Nail A; Akhatov, Iskander S

    2017-02-01

    The paper is dedicated to mathematical modeling of self-organization of bubbly liquids in acoustic fields. A continuum model describing the two-way interaction of diluted polydisperse bubbly liquids and acoustic fields in weakly-nonlinear approximation is studied analytically and numerically in the one-dimensional case. It is shown that the regimes of self-organization of monodisperse bubbly liquids can be controlled by only a few dimensionless parameters. Two basic modes, clustering and propagating shock waves of void fraction (acoustically induced transparency), are identified and criteria for their realization in the space of parameters are proposed. A numerical method for solving of one-dimensional self-organization problems is developed. Computational results for mono- and polydisperse systems are discussed.

  8. Phase transfer membrane supported liquid-liquid-liquid microextraction combined with large volume sample injection capillary electrophoresis-ultraviolet detection for the speciation of inorganic and organic mercury.

    PubMed

    Li, Pingjing; Zhang, Xing; Hu, Bin

    2011-12-30

    In this paper, a novel sample pretreatment technique termed phase transfer based liquid-liquid-liquid microextraction (PT-LLLME) was proposed for the simultaneous extraction of inorganic and organic mercury species. In PT-LLLME, an intermediate solvent (acetonitrile) was added into the donor phase to improve the contacting between target mercury species and complexing reagent. Meanwhile, a membrane supported (MS)-LLLME unit was designed to realize the PT-LLLME procedure. By using nylon membrane as supporting carrier, larger than 50 μL of acceptor solution could be hung up. Following PT/MS-LLLME, the acceptor solutions were directly analyzed by large volume sample stacking capillary electrophoresis/ultraviolet detection (LVSS-CE/UV). Accordingly, a new method of PT/MS-LLLME combined with LVSS-CE/UV was developed for the simultaneous speciation of inorganic and organic mercury species. Parameters affecting the extraction efficiency of PT/MS-LLLME were investigated in details. Under the optimized conditions, enrichment factors (EFs) ranging from 160- to 478-fold were obtained for the extraction of target mercury species by PT/MS-LLLME. By combining PT/MS-LLLME with LVSS-CE/UV, EFs were magnified up to 12,138-fold and the limits of detection (at a signal-to-noise ratio of 3) were at sub ppb level. The established approach of PT/MS-LLLME-LVSS-CE/UV was successfully applied to simultaneous determination of inorganic and organic mercury species in biological samples and environmental water samples.

  9. Protein renaturation by the liquid organic salt ethylammonium nitrate.

    PubMed Central

    Summers, C. A.; Flowers, R. A.

    2000-01-01

    The room-temperature liquid salt, ethylammonium nitrate (EAN), has been used to enhance the recovery of denatured-reduced hen egg white lysozyme (HEWL). Our results show that EAN has the ability to prevent aggregation of the denatured protein. The use of EAN as a refolding additive is advantageous because the renaturation is a one-step process. When HEWL was denatured reduced using routine procedures and renatured using EAN as an additive, HEWL was found to regain 75% of its activity. When HEWL was denatured and reduced in neat EAN, dilution resulted in over 90% recovery of active protein. An important aspect of this process is that renaturation of HEWL occurs at concentrations of 1.6 mg/mL, whereas other renaturation processes occur at significantly lower protein concentrations. Additionally, the refolded-active protein can be separated from the molten salt by simple desalting methods. Although the use of a low-temperature molten salt in protein renaturation is unconventional, the power of this approach lies in its simplicity and utility. PMID:11106174

  10. Enhanced mineralization of organic compounds in nonaqueous-phase liquids

    SciTech Connect

    Labare, M.P.; Alexander, M.

    1995-11-01

    Biodegradation of phenanthrene, biphenyl, or di(2-ethylhexyl) phthalate initially present in a variety of nonaqueous-phase liquids (NAPLs) was slow in samples of soil and aquifer solids. The NAPLs were hexadecane, dibutyl phthalate, 2, 2, 4 ,4, 6, 8, 8-heptamethylnonane, cyclohexane, commercial oils, crude oil, creosote, and kerosene. Slurrying the soil or aquifer solids markedly enhanced the rate and extent of mineralization of the test compounds initially in many of the NAPLs. Both the low rate and extent of mineralization of the three compounds initially in dibutyl phthalate in soil slurries and of di(2- ethylhexyl) phthalate in heptamethylnonane present in slurries of aquifer solids were increased by inoculation of acclimated microbial cultures. Increasing the NAPL volume decreased phenanthrene biodegradation in soil, but the effect of larger NAPL volume could be alleviated by slurrying and inoculation. The rate or extent of mineralization in aquifer slurries of di(2-ethylhexyi) phthalate initially in some NAPLs was increased by addition of N and P, and inoculation further enhanced the degradation.

  11. Dispersive liquid-liquid microextraction based on solidification of floating organic droplets followed by high performance liquid chromatography for the determination of duloxetine in human plasma.

    PubMed

    Suh, Joon Hyuk; Lee, Yun Young; Lee, Hee Joo; Kang, Myunghee; Hur, Yeoun; Lee, Sun Neo; Yang, Dong-Hyug; Han, Sang Beom

    2013-03-05

    A novel dispersive liquid-liquid microextraction method based on solidification of floating organic droplets (DLLME-SFO) technique was developed for the determination of duloxetine in human plasma samples by high performance liquid chromatography with fluorescence detection (HPLC-FLD). During the extraction procedure, plasma protein was precipitated by using a mixture of zinc sulfate solution and acetonitrile. After the protein precipitation step, duloxetine in an alkaline sample solution was quickly extracted by DLLME-SFO with 50 μL of 1-undecanol (extractant). Disperser was unnecessary because the small amount of remaining acetonitrile, which acts as a protein precipitating reagent, was also employed as a disperser; therefore, organic solvent consumption was reduced as much as possible. The emulsion was centrifuged and then fine droplets were floated to the top of the sample solution. The floated droplets were solidified in an ice bath and easily transferred. Various DLLME-SFO parameters such as extractant type, extractant amount, ionic strength, pH and extraction time were optimized. The chromatographic separation of duloxetine was carried out using ethanol as mobile phase. Validation of the method was performed with respect to linearity, intra- and inter-day accuracy and precision, limit of quantification (LOQ), and recovery. Calibration curves for duloxetine showed good linearity with correlation coefficients (r²) higher than 0.99. The method showed good precision and accuracy, with intra- and inter-assay coefficients of variation less than 15% (LOQ: less than 20%) at all concentrations. The recovery was carried out following the standard addition procedure with yields ranging from 59.6 to 65.5%. A newly developed environmentally friendly method was successfully applied to the pharmacokinetic study of duloxetine in human plasma and was shown to be an alternative green approach compared with the conventional solid-phase microextraction (SPME) and dispersive

  12. Liquid-liquid phase separation in aerosol particles: Dependence on O:C, organic functionalities, and compositional complexity

    NASA Astrophysics Data System (ADS)

    Song, M.; Marcolli, C.; Krieger, U. K.; Zuend, A.; Peter, T.

    2012-10-01

    Atmospheric aerosol particles may undergo liquid-liquid phase separation (LLPS) when exposed to varying relative humidity. In this study we investigated the occurrence of LLPS for mixtures consisting of up to ten organic compounds, ammonium sulfate, and water in relationship with the organic oxygen-to-carbon (O:C) ratio. LLPS always occurred for O:C < 0.56, never occurred for O:C > 0.80, and depended on the specific types and compositions of organic functional groups in the regime 0.56 < O:C < 0.80. In the intermediate regime, mixtures with a high share of aromatic compounds shifted the limit of occurrence of LLPS to lower O:C ratios. The number of mixture components and the spread of the O:C range did not notably influence the conditions for LLPS to occur. Since in ambient aerosols O:C range typically between 0.2 and 1.0, LLPS is expected to be a common feature of tropospheric aerosols.

  13. Liquid-Liquid Extraction and Solid Phase Extraction for Urinary Organic Acids: A Comparative Study from a Resource Constraint Setting.

    PubMed

    Kumari, Chandrawati; Varughese, Bijo; Ramji, Siddarth; Kapoor, Seema

    2016-10-01

    Pre analytical process of extraction for accurate detection of organic acids is a crucial step in diagnosis of organic acidemias by GCMS analysis. This process is accomplished either by solid phase extraction (SPE) or by liquid-liquid extraction (LLE). Both extraction procedures are used in different metabolic laboratories all over the world. In this study we compared these two extraction procedures in respect of precision, accuracy, percent recovery of metabolites, number of metabolites isolated, time and cost in a resource constraint setup. We observed that the mean recovery from SPE was 84.1 % and by LLE it was 77.4 % (p value <0.05). Moreover, the average number of metabolites isolated by SPE and LLE was 161.8 ± 18.6 and 140.1 ± 20.4 respectively. The processing cost of LLE was economical. In a cost constraint setting using LLE may be the practical option if used for organic acid analysis.

  14. Reactive uptake of organic compounds by liquid sulfuric acid.

    NASA Astrophysics Data System (ADS)

    Roberts, J.; Michelsen, R.

    2003-04-01

    The uptake of several organic compounds by laboratory surrogates for tropospheric sulfuric acid particles were investigated by mass spectrometry and infrared reflection-absorption spectroscopy. Among the compounds studied were acetone [(CH_3)_2CO], 2,4-hexanedione [CH_3CO(CH_2)_2COCH_3, MBO], and 2-methyl-3-buten-2-ol [CH_2CHC(CH_3)_2OH]. Experiments were carried out on ultrathin sulfuric acid films (ca. 10-100 monolayer equivalents thick) as functions of organic partial pressure, temperature, and acid composition. Acetone uptake is irreversible for acids that contain >70 weight percent (wt. %) H_2SO4, with kinetics that are second-order in concentration of dissolved acetone. Hexanedione and MBO are irreversibly taken for all acid compositions investigated (60-96 wt. %), with first-order uptake kinetics. In all cases, the irreversible uptake is a consequence of sulfuric acid catalyzed reactions that lead to the formation of new C-C bonds. Implications of these results for heterogeneous tropospheric chemistry will be discussed.

  15. PREDICTION OF THE SOLUBILITY, ACTIVITY COEFFICIENT AND LIQUID/LIQUID PARTITION COEFFICIENT OF ORGANIC COMPOUNDS

    EPA Science Inventory

    Solvation models, based on fundamental chemical structure theory, were developed in the SPARC mechanistic tool box to predict a large array of physical properties of organic compounds in water and in non-aqueous solvents strictly from molecular structure. The SPARC self-interact...

  16. PREDICTION OF THE SOLUBILITY, ACTIVITY COEFFICIENT AND LIQUID/LIQUID PARTITION COEFFICIENT OF ORGANIC COMPOUNDS

    EPA Science Inventory

    Solvation models, based on fundamental chemical structure theory, were developed in the SPARC mechanistic tool box to predict a large array of physical properties of organic compounds in water and in non-aqueous solvents strictly from molecular structure. The SPARC self-interact...

  17. Biogas production from the mechanically pretreated, liquid fraction of sorted organic municipal solid wastes.

    PubMed

    Alvarado-Lassman, A; Méndez-Contreras, J M; Martínez-Sibaja, A; Rosas-Mendoza, E S; Vallejo-Cantú, N A

    2017-06-01

    The high liquid content in fruit and vegetable wastes makes it convenient to mechanically separate these wastes into mostly liquid and solid fractions by means of pretreatment. Then, the liquid fraction can be treated using a high-rate anaerobic biofilm reactor to produce biogas, simultaneously reducing the amount of solids that must be landfilled. In this work, the specific composition of municipal solid waste (MSW) in a public market was determined; then, the sorted organic fraction of municipal solid waste was treated mechanically to separate and characterize the mostly liquid and solid fractions. Then, the mesophilic anaerobic digestion for biogas production of the first fraction was evaluated. The anaerobic digestion resulted in a reduced hydraulic retention time of two days with high removal of chemical oxygen demand, that is, 88% on average, with the additional benefit of reducing the mass of the solids that had to be landfilled by about 80%.

  18. Ionic Liquids Beyond Simple Solvents: Glimpses at the State of the Art in Organic Chemistry.

    PubMed

    Kuchenbuch, Andrea; Giernoth, Ralf

    2015-12-01

    Within the last 25 years ionic liquids have written a tremendous success story, which is documented in a nearly uncountable amount of original research papers, reviews, and numerous applications in research and industry. These days, ionic liquids can be considered as a mature class of compounds for many different applications. Frequently, they are used as neoteric solvents for chemical tansformations, and the number of reviews on this field of research is huge. In this focused review, though, we are trying to evaluate the state of the art of ionic liquid chemistry beyond using them simply as solvents for chemical transformations. It is not meant to be a comprehensive overview on the topic; the choice of emphasis and examples rather refects the authors' personal view on the field. We are especially highlighting fields in which we believe the most fundamental developments within the next five years will take place: biomass processing, (chiral) ionic liquids from natural sources, biotransformations, and organic synthesis.

  19. Levitation and Self-Organization of Liquid Microdroplets over Dry Heated Substrates

    NASA Astrophysics Data System (ADS)

    Zaitsev, Dmitry V.; Kirichenko, Dmitry P.; Ajaev, Vladimir S.; Kabov, Oleg A.

    2017-09-01

    Levitating droplets of liquid condensate are known to organize themselves into ordered arrays over hot liquid-gas interfaces. We report experimental observation of similar behavior over a dry heated solid surface. Even though the lifetime of the array is shorter in this case, its geometric characteristics are remarkably similar to the case of droplets levitating over liquid-gas interfaces. A simple model is developed that predicts the mechanisms of both droplet levitation and interdroplet interaction leading to pattern formation over a dry surface; the model is shown to be in good agreement with the experimental data. Using the insights from the new experiments, we are able to resolve some long-standing controversies pertaining to the mechanism of levitation of droplets over liquid-gas interfaces.

  20. Capture and release of mixed acid gasses with binding organic liquids

    DOEpatents

    Heldebrant, David J.; Yonker, Clement R.

    2010-09-21

    Reversible acid-gas binding organic liquid systems that permit separation and capture of one or more of several acid gases from a mixed gas stream, transport of the liquid, release of the acid gases from the ionic liquid and reuse of the liquid to bind more acid gas with significant energy savings compared to current aqueous systems. These systems utilize acid gas capture compounds made up of strong bases and weak acids that form salts when reacted with a selected acid gas, and which release these gases when a preselected triggering event occurs. The various new materials that make up this system can also be included in various other applications such as chemical sensors, chemical reactants, scrubbers, and separators that allow for the specific and separate removal of desired materials from a gas stream such as flue gas.

  1. Supramolecular [60]fullerene liquid crystals formed by self-organized two-dimensional crystals.

    PubMed

    Zhang, Xiaoyan; Hsu, Chih-Hao; Ren, Xiangkui; Gu, Yan; Song, Bo; Sun, Hao-Jan; Yang, Shuang; Chen, Erqiang; Tu, Yingfeng; Li, Xiaohong; Yang, Xiaoming; Li, Yaowen; Zhu, Xiulin

    2015-01-02

    Fullerene-based liquid crystalline materials have both the excellent optical and electrical properties of fullerene and the self-organization and external-field-responsive properties of liquid crystals (LCs). Herein, we demonstrate a new family of thermotropic [60]fullerene supramolecular LCs with hierarchical structures. The [60]fullerene dyads undergo self-organization driven by π-π interactions to form triple-layer two-dimensional (2D) fullerene crystals sandwiched between layers of alkyl chains. The lamellar packing of 2D crystals gives rise to the formation of supramolecular LCs. This design strategy should be applicable to other molecules and lead to an enlarged family of 2D crystals and supramolecular liquid crystals. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Self-Assembled Fibers Containing Stable Organic Radical Moieties: Alignment and Magnetic Properties in Liquid Crystals.

    PubMed

    Eimura, Hiroki; Umeta, Yoshikazu; Tokoro, Hiroko; Yoshio, Masafumi; Ohkoshi, Shin-Ichi; Kato, Takashi

    2016-06-20

    Macroscopically oriented stable organic radicals have been obtained by using a liquid-crystalline (LC) gel composed of an l-isoleucine-based low molecular weight gelator containing a 2,2,6,6-tetramethylpiperidine 1-oxyl moiety. The LC gel has allowed magnetic measurements of the oriented organic radical. The gelator has formed fibrous aggregates in liquid crystals via intermolecular hydrogen bonds. The fibrous aggregates of the radical gelator are formed and oriented on cooling by applying a magnetic field to the mixture of liquid crystals and the gelator. Superconducting quantum interference device (SQUID) measurements have revealed that both oriented and nonoriented fibrous aggregates exhibited antiferromagnetic interactions, in which super-exchange interaction constant J is estimated as -0.89 cm(-1) . © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Self-organization and electrooptical characteristics of a nematic liquid crystal-cellulose diacetate composite

    NASA Astrophysics Data System (ADS)

    Sadovoy, A. V.; Shipovskaya, A. B.; Nazvanov, V. F.

    2008-12-01

    Stable self-organization process has been observed during the formation of thin films of a composite based on a nematic liquid crystal and a cellulose acetate polymer matrix. Optical transmission characteristics and electrooptical response time of the composite have been theoretically calculated and experimentally studied.

  4. IMPACT OF ORGANIC COMPOUNDS ON THE CONCENTRATIONS OF LIQUID WATER IN AMBIENT PM2.5

    EPA Science Inventory

    A field study was undertaken during the summer of 2000 to assess the impact of the presence of organic compounds on the liquid water concentrations of PM2.5 samples. The selected site, located in Research Triangle Park, North Carolina, was in a semi-rural environment with expe...

  5. Fertigation with liquid fish emulsion for organic production of highbush blueberry

    USDA-ARS?s Scientific Manuscript database

    Liquid fish emulsion is a common fertilizer used for organic production of highbush blueberry. The product is often applied by hand or with a sprayer but can also be injected through a drip irrigation system, otherwise referred to as fertigation. Fertigation is more efficient and less labor-intensiv...

  6. Visualizing Molecular Chirality in the Organic Chemistry Laboratory Using Cholesteric Liquid Crystals

    ERIC Educational Resources Information Center

    Popova, Maia; Bretz, Stacey Lowery; Hartley, C. Scott

    2016-01-01

    Although stereochemistry is an important topic in second-year undergraduate organic chemistry, there are limited options for laboratory activities that allow direct visualization of macroscopic chiral phenomena. A novel, guided-inquiry experiment was developed that allows students to explore chirality in the context of cholesteric liquid crystals.…

  7. Dissolution, Cyclodextrin-Enhanced Solubilization, and Mass Removal of an Ideal Multicomponent Organic Liquid

    PubMed Central

    Carroll, Kenneth C.; Brusseau, Mark L.

    2010-01-01

    Laboratory experiments and mathematical modeling were conducted to examine the influence of a hydroxypropyl-beta-cyclodextrin (HPCD) solution on the dissolution of single- and three-component organic liquids. The results of batch experiments showed that HPCD-enhanced solubilization of the organic-liquid mixtures was ideal (describable using Raoult’s Law), and that solubilization-enhancement factors were independent of mixture composition. Addition of the HPCD solution to columns containing residual saturations of the organic liquid enhanced the dissolution and removal of all three compounds in the mixture. The results of the column experiments and multicomponent rate-limited dissolution modeling suggest that solubilization was ideal for both water and cyclodextrin flushing. Concomitantly, the mass-flux reduction versus mass removal behavior was ideal for all experiments. Mass transfer was increased for HPCD solubilization relative to the water flushing due to solubility and concentration-gradient enhancement. Organic-liquid composition did not significantly impact mass transfer coefficients, and fractional mass removal behavior during HPCD solubilization was nearly identical for each compound whether present as a single component or in a mixture. Additionally, mass transfer coefficients for aqueous and HPCD solubilization for single and multicomponent mixtures were not statistically different upon normalizing by the solubility enhancement factor. PMID:19233508

  8. IMPACT OF ORGANIC COMPOUNDS ON THE CONCENTRATIONS OF LIQUID WATER IN AMBIENT PM2.5

    EPA Science Inventory

    A field study was undertaken during the summer of 2000 to assess the impact of the presence of organic compounds on the liquid water concentrations of PM2.5 samples. The selected site, located in Research Triangle Park, North Carolina, was in a semi-rural environment with expe...

  9. The Recovery and Identification of Flammable Liquids in Suspected Arsons: An Undergraduate Organic Experiment

    ERIC Educational Resources Information Center

    Blackledge, Robert D.

    1974-01-01

    Describes an experiment which can be used to test for the use of accelerants in the origin of a fire. Involves distillation and gas liquid chromatography to identify the accelerants, thus combining two experiments ordinarily included in the beginning organic laboratory. (SLH)

  10. Visualizing Molecular Chirality in the Organic Chemistry Laboratory Using Cholesteric Liquid Crystals

    ERIC Educational Resources Information Center

    Popova, Maia; Bretz, Stacey Lowery; Hartley, C. Scott

    2016-01-01

    Although stereochemistry is an important topic in second-year undergraduate organic chemistry, there are limited options for laboratory activities that allow direct visualization of macroscopic chiral phenomena. A novel, guided-inquiry experiment was developed that allows students to explore chirality in the context of cholesteric liquid crystals.…

  11. ON-LINE DEOXYGENATION IN REDUCTIVE (AND OXIDATIVE) AMPEROMETRIC DETECTION: ENVIRONMENTAL APPLICATIONS IN THE LIQUID CHROMATOGRAPHY OF ORGANIC PEROXIDES

    EPA Science Inventory

    Cyclic voltammetry was used qualitatively to characterize and determine the feasibility of the oxidation and reduction of selected organic peroxides and hydroperoxides at a glassy carbon electrode. Organic peroxides were determined using reversed-phase high-performance liquid chr...

  12. ON-LINE DEOXYGENATION IN REDUCTIVE (AND OXIDATIVE) AMPEROMETRIC DETECTION: ENVIRONMENTAL APPLICATIONS IN THE LIQUID CHROMATOGRAPHY OF ORGANIC PEROXIDES

    EPA Science Inventory

    Cyclic voltammetry was used qualitatively to characterize and determine the feasibility of the oxidation and reduction of selected organic peroxides and hydroperoxides at a glassy carbon electrode. Organic peroxides were determined using reversed-phase high-performance liquid chr...

  13. Computation of liquid-liquid equilibria and phase stabilities: implications for RH-dependent gas/particle partitioning of organic-inorganic aerosols

    NASA Astrophysics Data System (ADS)

    Zuend, A.; Marcolli, C.; Peter, T.; Seinfeld, J. H.

    2010-08-01

    Semivolatile organic and inorganic aerosol species partition between the gas and aerosol particle phases to maintain thermodynamic equilibrium. Liquid-liquid phase separation into an organic-rich and an aqueous electrolyte phase can occur in the aerosol as a result of the salting-out effect. Such liquid-liquid equilibria (LLE) affect the gas/particle partitioning of the different semivolatile compounds and might significantly alter both particle mass and composition as compared to a one-phase particle. We present a new liquid-liquid equilibrium and gas/particle partitioning model, using as a basis the group-contribution model AIOMFAC (Zuend et al., 2008). This model allows the reliable computation of the liquid-liquid coexistence curve (binodal), corresponding tie-lines, the limit of stability/metastability (spinodal), and further thermodynamic properties of multicomponent systems. Calculations for ternary and multicomponent alcohol/polyol-water-salt mixtures suggest that LLE are a prevalent feature of organic-inorganic aerosol systems. A six-component polyol-water-ammonium sulphate system is used to simulate effects of relative humidity (RH) and the presence of liquid-liquid phase separation on the gas/particle partitioning. RH, salt concentration, and hydrophilicity (water-solubility) are identified as key features in defining the region of a miscibility gap and govern the extent to which compound partitioning is affected by changes in RH. The model predicts that liquid-liquid phase separation can lead to either an increase or decrease in total particulate mass, depending on the overall composition of a system and the particle water content, which is related to the hydrophilicity of the different organic and inorganic compounds. Neglecting non-ideality and liquid-liquid phase separations by assuming an ideal mixture leads to an overestimation of the total particulate mass by up to 30% for the composition and RH range considered in the six-component system

  14. Computation of liquid-liquid equilibria and phase stabilities: implications for RH-dependent gas/particle partitioning of organic-inorganic aerosols

    NASA Astrophysics Data System (ADS)

    Zuend, A.; Marcolli, C.; Peter, T.; Seinfeld, J. H.

    2010-05-01

    Semivolatile organic and inorganic aerosol species partition between the gas and aerosol particle phases to maintain thermodynamic equilibrium. Liquid-liquid phase separation into an organic-rich and an aqueous electrolyte phase can occur in the aerosol as a result of the salting-out effect. Such liquid-liquid equilibria (LLE) affect the gas/particle partitioning of the different semivolatile compounds and might significantly alter both particle mass and composition as compared to a one-phase particle. We present a new liquid-liquid equilibrium and gas/particle partitioning model, using as a basis the group-contribution model AIOMFAC (Zuend et al., 2008). This model allows the reliable computation of the liquid-liquid coexistence curve (binodal), corresponding tie-lines, the limit of stability/metastability (spinodal), and further thermodynamic properties of the phase diagram. Calculations for ternary and multicomponent alcohol/polyol-water-salt mixtures suggest that LLE are a prevalent feature of organic-inorganic aerosol systems. A six-component polyol-water-ammonium sulphate system is used to simulate effects of relative humidity (RH) and the presence of liquid-liquid phase separation on the gas/particle partitioning. RH, salt concentration, and hydrophilicity (water-solubility) are identified as key features in defining the region of a miscibility gap and govern the extent to which compound partitioning is affected by changes in RH. The model predicts that liquid-liquid phase separation can lead to either an increase or decrease in total particulate mass, depending on the overall composition of a system and the particle water content, which is related to the hydrophilicity of the different organic and inorganic compounds. Neglecting non-ideality and liquid-liquid phase separations by assuming an ideal mixture leads to an overestimation of the total particulate mass by up to 30% for the composition and RH range considered in the six-component system simulation

  15. Ionic liquid accelerates the crystallization of Zr-based metal-organic frameworks.

    PubMed

    Sang, Xinxin; Zhang, Jianling; Xiang, Junfeng; Cui, Jie; Zheng, Lirong; Zhang, Jing; Wu, Zhonghua; Li, Zhihong; Mo, Guang; Xu, Yuan; Song, Jinliang; Liu, Chengcheng; Tan, Xiuniang; Luo, Tian; Zhang, Bingxing; Han, Buxing

    2017-08-02

    The Zr-based metal-organic frameworks are generally prepared by solvothermal procedure. To overcome the slow kinetics of nucleation and crystallization of Zr-based metal-organic frameworks is of great interest and challenging. Here, we find that an ionic liquid as solvent can significantly accelerate the formation of Zr-based metal-organic frameworks at room temperature. For example, the reaction time is shortened to 0.5 h in 1-hexyl-3-methylimidazolium chloride for Zr-based metal-organic framework formation, while that in the conventional solvent N,N-dimethylformamide needs at least 120 h. The reaction mechanism was investigated in situ by (1)H nuclear magnetic resonance, spectroscopy synchrotron small angle X-ray scattering and X-ray absorption fine structure. This rapid, low-energy, and facile route produces Zr-based metal-organic framework nanoparticles with small particle size, missing-linker defects and large surface area, which can be used as heterogeneous catalysts for Meerwein-Ponndorf-Verley reaction.Crystallization kinetics of metal-organic frameworks in conventional organic solvents are usually very slow. Here, the authors show that an ionic liquid medium accelerates considerably the formation of Zr-based metal-organic frameworks that are active catalysts in the Meerwein-Ponndorf-Verley reaction.

  16. Safety analysis of exothermic reaction hazards associated with the organic liquid layer in tank 241-C-103

    SciTech Connect

    Postma, A.K.; Bechtold, D.B.; Borsheim, G.L.; Grisby, J.M.; Guthrie, R.L.; Kummerer, M.; Turner, D.A.; Plys, M.G.

    1994-03-01

    Safety hazards associated with the interim storage of a potentially flammable organic liquid in waste Tank C-103 are identified and evaluated. The technical basis for closing the unreviewed safety question (USQ) associated with the floating liquid organic layer in this tank is presented.

  17. Synthesis and characterization of low viscosity carbon dioxide binding organic liquids for flue gas clean up

    SciTech Connect

    Koech, Phillip K.; Malhotra, Deepika; Heldebrant, David J.; Cantu Cantu, David; Glezakou, Vassiliki Alexandra; Rousseau, Roger J.

    2015-01-01

    Climate change is partly attributed to global anthropogenic carbon dioxide (CO2) emission to the atmosphere. These environmental effects can be mitigated by CO2 capture, utilization and storage. Alkanolamine solvents, such as monoethanolamine (MEA), which bind CO2 as carbamates or bicarbonate salts are used for CO2 capture in niche applications. These solvents consist of approximately 30 wt% of MEA in water, exhibiting a low, CO2-rich viscosity, fast kinetics and favorable thermodynamics. However, these solvents have low CO2 capacity and high heat capacity of water, resulting in prohibitively high costs of thermal solvent regeneration. Effective capture of the enormous amounts of CO2 produced by coal-fired plants requires a material with high CO2 capacity and low regeneration energy requirements. To this end, several water-lean transformational solvents systems have been developed in order to reduce these energy penalties. These technologies include nano-material organic hybrids (NOHMs), task-specific, protic and conventional ionic liquids, phase change solvents. As part of an ongoing program in our group, we have developed new water lean transformational solvents known as CO2 binding organic liquids (CO2BOLs) which have the potential to be energy efficient CO2 capture solvents. These solvents, also known as switchable ionic liquids meaning, are organic solvents that can reversibly transform from non- ionic to ionic form and back. The zwitterionic state in these liquids is formed when low polarity non-ionic alkanolguanidines or alkanolamidines react with CO2 or SO2 to form ionic liquids with high polarity. These polar ionic liquids can be thermally converted to the less polar non-ionic solvent by releasing CO2.

  18. Extraction of lignins from aqueous-ionic liquid mixtures by organic solvents.

    PubMed

    Xin, Qin; Pfeiffer, Katie; Prausnitz, John M; Clark, Douglas S; Blanch, Harvey W

    2012-02-01

    The commercial development of ionic liquids (ILs) to pretreat lignocellulose by dissolution of whole biomass and cellulose precipitation by addition of water is hindered by the absence of an effective technique to recover the lignin content of the biomass from the IL. Three organic solvents [ethyl acetate, 1,4-dioxane, and tetrahydrofuran (THF)] were studied for their ability to form a two-liquid-phase system with water and 1-ethyl-3-methylimidazolium acetate ([C(2)mim][OAc]), and for partitioning model lignins and lignin monomers between the two liquid phases. Ternary diagrams were obtained for three [C(2)mim][OAc]/organic solvent/water systems at 22°C. Partition coefficients were measured for several types of lignin in these three systems. Partition coefficients increase with rising water content in the IL phase, and depend strongly on the type of lignin and on the organic solvent. Partition coefficients rise as the pH of the ionic-liquid-rich phase falls. Small molecule model lignin monomer compounds (guaiacol, syringaldehyde) are also readily extracted from the IL/water system by THF. Copyright © 2011 Wiley Periodicals, Inc.

  19. Selective scattering polymer dispersed liquid crystal film for light enhancement of organic light emitting diode.

    PubMed

    Jiang, Jinghua; McGraw, Greg; Ma, Ruiqing; Brown, Julie; Yang, Deng-Ke

    2017-02-20

    We developed a novel light enhancing film for an organic light emitting diode (OLED) based on polymer dispersed liquid crystal (PDLC). In the film, the liquid crystal droplets are unidirectionally aligned along the film normal direction and exhibit selective scattering. The film scatters light emitted only in directions with large incident angles but not light emitted in directions with small incident angles. When the light is scattered, it changes propagation direction and exits the OLED. The PDLC film reduces the total internal reflection and thus can significantly increase the light efficiency of the OLED.

  20. CO2-Binding-Organic-Liquids-Enhanced CO2 Capture using Polarity-Swing-Assisted Regeneration

    SciTech Connect

    Zhang, Jian; Kutnyakov, Igor; Koech, Phillip K.; Zwoster, Andy; Howard, Chris; Zheng, Feng; Freeman, Charles J.; Heldebrant, David J.

    2013-01-01

    A new solvent-based CO2 capture process couples the unique attributes of non-aqueous, CO2-binding organic liquids (CO2BOLs) with the newly discovered polarity-swing-assisted regeneration (PSAR) process that is unique to switchable ionic liquids. Laboratory measurements with PSAR indicate the ability to achieve a regeneration effect at 75°C comparable to that at 120°C using thermal regeneration only. Initial measurements also indicate that the kinetic behavior of CO2 release is also improved with PSAR. Abstract cleared PNWD-SA-9743

  1. Determination of 13 Organic Toxicants in Human Blood by Liquid-Liquid Extraction Coupling High-Performance Liquid Chromatography Tandem Mass Spectrometry.

    PubMed

    Song, Aiying

    2016-01-01

    Pesticides and antidepressants are frequently misused in drug-facilitated crime because of their toxicological effect and easy-availability. Therefore, it is essential for the development of a simple and reliable method for the determination of these organic toxicants in biological fluids. Here, we report on an applicable method by the combination of optimized liquid-liquid extraction (LLE) procedure and high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) to identify and quantify dimethoate, omethoate, dichlorvos, carbofuran, fenpropathrin, diazepam, estazolam, alprazolam, triazolamm, chlorpromazine, phenergan, barbitone and phenobarbital in human blood. The method demonstrated a linear calibration curve in range of 20 - 500 μg/L (r > 0.994). The accuracy evaluated by recovery spiked at three different concentrations (50, 100 and 200 μg/L) was in the range of 58.8 - 83.1% with a relative standard deviations (RSD) of 3.7 - 7.4%. The limits of quantification ranged over 6.7 - 33.3 μg/L. This method was proved to be simple and reliable, and was thus successfully applied to forensic toxicology.

  2. Rapid extraction and determination of amphetamines in human urine samples using dispersive liquid-liquid microextraction and solidification of floating organic drop followed by high performance liquid chromatography.

    PubMed

    Ahmadi-Jouibari, Toraj; Fattahi, Nazir; Shamsipur, Mojtaba

    2014-06-01

    A novel, rapid, simple and sensitive dispersive liquid-liquid microextraction method based on the solidification of floating organic drop (DLLME-SFO) combined with high-performance liquid chromatography-ultraviolet detection (HPLC-UV) was used to determine amphetamine and methamphetamine in urine samples. The factors affecting the extraction efficiency of DLLME-SFO such as the kind and volume of the extraction and the disperser solvents, effect of concentration of K2CO3 and extraction time were investigated and the optimal extraction conditions were established. Under the optimum conditions (extraction solvent: 30.0μl 1-undecanol; disperser solvent: 300μl acetonitrile; buffer concentration: 2% (w/v) K2CO3 and extraction time: 1min), calibration curves are linear in the range of 10-3000μgl(-1) and limit of detections (LODs) are in the range of 2-8μgl(-1). The relative standard deviations (RSDs) for 100μgl(-1) of amphetamine and methamphetamine in diluted urine are in the range of 6.2-7.8% (n=7). The method was successfully applied for the determination of amphetamine and methamphetamine in the actual urine samples. The relative recoveries of urine samples spiked with amphetamine and methamphetamine are 87.8-113.2%. The obtained results show that DLLME-SFO combined with HPLC-UV is a fast and simple method for the determination of amphetamine and methamphetamine in urine.

  3. Cationic Ionic Liquids Organic Ligands Based Metal-Organic Frameworks for Fabrication of Core-Shell Microspheres for Hydrophilic Interaction Liquid Chromatography.

    PubMed

    Dai, Qian; Ma, Junqian; Ma, Siqi; Wang, Shengyu; Li, Lijun; Zhu, Xianghui; Qiao, Xiaoqiang

    In this study, new metal-organic frameworks (MOFs) nanocrystals modified SiO2 core-shell microspheres were designed with cationic ionic liquids (ILs) 1,3-bis(4-carboxybutyl)imidazolium bromide (ILI) as organic ligands. By further adjustment the growth cycles, the new ILI-01@SiO2 core-shell stationary phase was facilely fabricated. The developed stationary phase was respectively characterized via element analysis, thermogravimetric analysis, scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectrometry. Because the introduction of cationic imidazolium-based ILs ILI for fabrication of the MOFs nanocrystals shell, the new stationary phase exhibits the retention mechanism of hydrophilic interaction liquid chromatography (HILIC). Many polar samples, such as amides, vitamins, nucleic acid bases, and nucleosides, were utilized to investigate the performance of the prepared ILI-01@SiO2 column. Compared to the conventional aminosilica column, the new ILI-01@SiO2 column displays high separation selectivity in a shorter separation time. Furthermore, the new ILI-01@SiO2 column was also used for detection of illegal melamine addition in the baby formula. All the above results demonstrate the new ILI-01@SiO2 core-shell stationary phase is of good potentials for high-selectivity separation the polar samples.

  4. Resistance switching of epitaxial VO2/Al2O3 heterostructure at room temperature induced by organic liquids

    NASA Astrophysics Data System (ADS)

    Yang, Mengmeng; Yang, Yuanjun; Hong, Bin; Huang, Haoliang; Hu, Sixia; Dong, Yongqi; Wang, Haibo; He, Hao; Zhao, Jiyin; Liu, Xuguang; Luo, Zhenlin; Li, Xiaoguang; Zhang, Haibin; Gao, Chen

    2015-03-01

    We studied using organic liquids (cyclohexane, n-butanol, and ethylene glycol) to modulate the transport properties at room temperature of an epitaxial VO2 film on a VO2/Al2O3 heterostructure. The resistance of the VO2 film increased when coated with cyclohexane or n-butanol, with maximum changes of 31% and 3.8%, respectively. In contrast, it decreased when coated with ethylene glycol, with a maximum change of -7.7%. In all cases, the resistance recovered to its original value after removing the organic liquid. This organic-liquid-induced reversible resistance switching suggests that VO2 films can be used as organic molecular sensors.

  5. Organic synthesis reactions on-water at the organic-liquid water interface.

    PubMed

    Butler, Richard N; Coyne, Anthony G

    2016-10-25

    Organic reactions that occur at the water interface for water-insoluble compounds, and reactions in water solution for water soluble compounds, has added a powerful dimension to prospects for organic synthesis under more beneficial economic and environmental conditions. Many organic molecules are partially soluble in water and reactions that appear as heterogeneous mixtures and suspensions may involve on-water and in-water reaction modes occurring simultaneously. The behavior of water molecules and organic molecules at this interface is discussed in the light of reported theoretical and experimental studies. The on-water catalytic effect, relative to neat reactions or organic solvents, ranges from factors of several hundred times to 1-2 times and it depends on the properties of reactant compounds. In some cases when on-water reactions produce quantitative yields of water-insoluble products they can reach ideal synthetic aspirations.

  6. Structure-directing effects of ionic liquids in the ionothermal synthesis of metal–organic frameworks

    PubMed Central

    Kelley, Steven P.; Rogers, Robin D.

    2017-01-01

    Traditional synthesis of metal–organic frameworks (MOFs) involves the reaction of a metal-containing precursor with an organic linker in an organic solvent at an elevated temperature, in what is termed a ‘solvothermal’ reaction. More recently, many examples have been reported of MOF synthesis in ionic liquids (ILs), rather than an organic solvent, in ‘ionothermal’ reactions. The high concentration of both cations and anions in an ionic liquid allows for the formation of new MOF structures in which the IL cation or anion or both are incorporated into the MOF. Most commonly, the IL cation is included in the open cavities of the MOF, countering the anionic charge of the MOF framework itself and acting as a template around which the MOF structure forms. Ionic liquids can also serve other structure-directing roles, for example, when an IL containing a single enantiomer of a chiral anion leads to a homochiral MOF, even though the IL anion is not itself incorporated into the MOF. A comprehensive review of ionothermal syntheses of MOFs, and the structure-directing effects of the ILs, is given. PMID:28875025

  7. Structure-directing effects of ionic liquids in the ionothermal synthesis of metal-organic frameworks.

    PubMed

    Vaid, Thomas P; Kelley, Steven P; Rogers, Robin D

    2017-07-01

    Traditional synthesis of metal-organic frameworks (MOFs) involves the reaction of a metal-containing precursor with an organic linker in an organic solvent at an elevated temperature, in what is termed a 'solvothermal' reaction. More recently, many examples have been reported of MOF synthesis in ionic liquids (ILs), rather than an organic solvent, in 'ionothermal' reactions. The high concentration of both cations and anions in an ionic liquid allows for the formation of new MOF structures in which the IL cation or anion or both are incorporated into the MOF. Most commonly, the IL cation is included in the open cavities of the MOF, countering the anionic charge of the MOF framework itself and acting as a template around which the MOF structure forms. Ionic liquids can also serve other structure-directing roles, for example, when an IL containing a single enantiomer of a chiral anion leads to a homochiral MOF, even though the IL anion is not itself incorporated into the MOF. A comprehensive review of ionothermal syntheses of MOFs, and the structure-directing effects of the ILs, is given.

  8. Organic-vapor-liquid-solid deposition with an impinging gas jet

    NASA Astrophysics Data System (ADS)

    Shaw, Daniel W.; Bufkin, Kevin; Baronov, Alexandr A.; Johnson, Brad L.; Patrick, David L.

    2012-04-01

    A method for rapid, mass-efficient deposition of highly crystalline organic films under near ambient conditions of pressure and temperature is reported based on delivery of an organic precursor via an impinging gas jet to a substrate coated by a thin liquid solvent layer. Films of the organic semiconductor tetracene were deposited by sublimation into a flow of argon carrier gas directed at an indium-tin-oxide/glass substrate coated by a thin layer of bis(2-ethylhexyl)sebecate, and growth was followed in situ with optical microscopy. A fluid dynamics model is applied to account for the gas phase transport and aggregation, and the results compared to experiment. The combination of gas jet delivery with an organic-vapor-liquid-solid growth mechanism leads to larger crystals and lower nucleation densities than on bare surfaces, with markedly different nucleation and growth kinetics. An explanation based on enhanced solution-phase diffusivity and a larger critical nucleus size in the liquid layer is proposed to account for the differences.

  9. Fast Scanning Calorimetry study of non-equilibrium relaxation in fragile organic liquids

    NASA Astrophysics Data System (ADS)

    Sadtchenko, Vlad; Bhattacharya, Deepanjan; O'Reilly, Liam

    2013-03-01

    Fast scanning calorimetry (FSC), capable of heating rates in excess of 1000000 K/s, was combined with vapor deposition technique to investigate non-equilibrium relaxation in micrometer thick viscous liquid films of several organic compounds (e.g.2-ethyl-1-hexanol, Toluene, and 1-propanol) under high vacuum conditions. Rapid heating of samples, vapor deposited at temperatures above their standard glass softening transition (Tg), resulted in observable endotherms which onset temperatures were strongly dependent on heating rate and the deposition temperature. Furthermore, all of the studied compounds were characterized by distinct critical deposition temperatures at which observation of endotherm became impossible. Based on the results of these studies, we have developed a simple model which makes it possible to infer the equilibrium enthalpy relaxation times for liquids from FSC data. We will discuss implications of these studies for contemporary models of non-equilibrium relaxation in glasses and supercooled liquids. Supported by NSF Grant 1012692.

  10. Predicting liquid densities of organic compounds: II, Nitrogen and sulfur compounds

    SciTech Connect

    Wood, G.O.; Weaver, T.B.

    1993-02-01

    Correlations of liquid densities have been extended to more classes of organic compounds. The products of liquid density and molecular weight at or near 20{degrees}C were previously found to be linear functions of the number and types of carbon atoms in the molecule. Cyclic carbon atoms contributed more to density than carbon atoms not part of a ring structure. Carbon atoms which occupy two rings have since been found to contribute even different increments. Additional databases of liquid densities have been set up for compounds with cyclic oxygen atoms, cyclic and noncyclic nitrogen atoms, and cyclic and noncyclic sulfur atoms. Correlation parameters have been obtained by fitting these data by least squares minimization.

  11. Separations of hazardous organics from gas and liquid feedstreams using phosphazene polymer membranes

    SciTech Connect

    Peterson, E.S.; Stone, M.L.; Cummings, D.G.; McCaffrey, R.R.

    1993-01-01

    The liquid-liquid and gas separation properties for the separation of hazardous organic feed streams using pervaporation and gas separation methods with poly[bis(phenoxy)phosphazene] based membranes are reported. Liquid transport behavior was determined using pervaporation techniques. The preliminary gas separations were studied using a mixed gas separation method which the authors have described previously. Using the membrane pervaporation technique, separation factors of 10,000 have been routinely achieved for the separation of methylene chloride from water. Other tests have shown similar results for the removal of hydrocarbon vapors from air. Membranes were prepared using solution casting techniques. Solvent evaporation rates during the casting and subsequent curing processes were controlled to provide a consistent membrane microstructure. These results suggest that polyphosphazene membrane technology could effectively be used in cleaning up air and ground water that has been contaminated with chlorinated hydrocarbons.

  12. Separation of trace amount of silver using dispersive liquid-liquid based on solidification of floating organic drop microextraction.

    PubMed

    Afzali, Daryoush; Mohadesi, Ali Reza; Jahromi, Behnoosh Bahadori; Falahnejad, Masoumeh

    2011-01-17

    In the present work, dispersive liquid-liquid microextraction based on solidification of floating organic drop was developed as a simple and rapid technique for separation of silver ions from aqueous samples. In this technique, 700 μL 0.02% of 5-(4'-dimethylamino benzyliden)-rhodanine (chelating agent) was added into the 10 mL analyte sample in a test tube and 30.0 μL 1-undecanol (extraction solvent) was injected shortly thereafter. The test tubes were sonicated, centrifuged and then some effective parameters on extraction and complex formation, such as type and volume of extraction and disperser solvent, pH, the amount of chelating agent and extraction time were optimized. The effect of the interfering ions on the analytes recovery was also investigated. The calibration graph was linear in the range of 0.10-10.0 ng mL(-1) with detection limit of 0.056 ng mL(-1) (n=8). The relative standard deviation (RSD) was ±4.3% (n=8, C=5.0 ng mL(-1)) and the enrichment factor was 250.0. The proposed method was applied for extraction and determination of silver in different water samples. Copyright © 2010 Elsevier B.V. All rights reserved.

  13. Determination of parabens in beverage samples by dispersive liquid-liquid microextraction based on solidification of floating organic droplet.

    PubMed

    Hou, Fang; Deng, Xiaoying; Jiang, Xinyu; Yu, Jingang

    2014-01-01

    A simple and efficient method for dispersive liquid-liquid microextraction of methylparaben, ethylparaben, propylparaben and butylparaben in real beverage samples was developed. It is making use of solidified floating organic droplets of 1-dodecanol which has low density and a proper melting point. Parameters influencing the extraction efficiency, such as the type of extraction and dispersive solvent, the volume of extraction and dispersive solvent, salt effect, pH, extraction time, were optimized and resulted in enrichment factors (EFs) of 84 for methylparaben, 103 for ethylparaben, 115 for propylparaben and 126 for butylparaben. The limits of detection for parabens were 1.52, 1.06, 0.32 and 0.17 ng/mL, respectively. Excellent linearity with coefficients of correlation from 0.9970 to 0.9997 was observed in the concentration range of 5-1,000 ng/mL. The repeatability of the proposed method expressed as relative standard deviations (RSDs) ranged from 2.54 to 3.89% (n = 5). The relative recoveries for parabens in beverage samples were good and in the ranges of 89.8-109.9, 90.2-107.3, 90.9-101.7 and 92.3-118.1%, respectively. Thus, the proposed method has excellent potential for the determination of parabens in beverage samples. © The Author [2013]. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  14. SIZE AND SHAPE OF PLEUROPNEUMONIA-LIKE ORGANISMS GROWN IN LIQUID MEDIA

    PubMed Central

    Weibull, C.; Lundin, Britt-Marie

    1962-01-01

    Weibull, C. (Central Bacteriological Laboratory of Stockholm City, Stockholm, Sweden), and Britt-Marie Lundin. Size and shape of pleuropneumonia-like organisms grown in liquid media. J. Bacteriol. 84:513–519. 1962.—Samples of liquid cultures containing mainly nonaggregated cells of Mycoplasma agalactiae or M. laidlawii were transferred to agar blocks containing the same medium as the liquid cultures. By use of a phase-contrast microscope, photomicrographs were made of the slide cultures immediately after they had been prepared, and the dimensions of a large number of pleuropneumonia-like organisms (PPLO) were measured. These measurements indicated that, in young cultures (incubated for 24 to 48 hr), the size of the cells did not vary much more than that of ordinary bacteria; 95% of the cells had a width of 0.2 to 0.6 μ. The growth of individual PPLO was followed during incubation of the slide cultures. It was found that 80 to 100% of the cells present in liquid overnight cultures divided and gave rise to microcolonies within a few hours. Rod-shaped, ellipsoidal, and spherical cells were seen in these cultures. Liquid cultures incubated for several days contained mainly spherical cells. Fewer than 5% of the cells in these cultures showed any indication of growth during incubation in slide cultures for 5 days. Photomicrographs of cells of M. agalactiae moving freely in liquid medium were taken with an electronic flash as the light source. The photographs thus obtained directly demonstrated the existence of rod-shaped cells. Images PMID:13999518

  15. On the implications of aerosol liquid water and phase separation for organic aerosol mass

    NASA Astrophysics Data System (ADS)

    Pye, Havala O. T.; Murphy, Benjamin N.; Xu, Lu; Ng, Nga L.; Carlton, Annmarie G.; Guo, Hongyu; Weber, Rodney; Vasilakos, Petros; Wyat Appel, K.; Hapsari Budisulistiorini, Sri; Surratt, Jason D.; Nenes, Athanasios; Hu, Weiwei; Jimenez, Jose L.; Isaacman-VanWertz, Gabriel; Misztal, Pawel K.; Goldstein, Allen H.

    2017-01-01

    Organic compounds and liquid water are major aerosol constituents in the southeast United States (SE US). Water associated with inorganic constituents (inorganic water) can contribute to the partitioning medium for organic aerosol when relative humidities or organic matter to organic carbon (OM / OC) ratios are high such that separation relative humidities (SRH) are below the ambient relative humidity (RH). As OM / OC ratios in the SE US are often between 1.8 and 2.2, organic aerosol experiences both mixing with inorganic water and separation from it. Regional chemical transport model simulations including inorganic water (but excluding water uptake by organic compounds) in the partitioning medium for secondary organic aerosol (SOA) when RH > SRH led to increased SOA concentrations, particularly at night. Water uptake to the organic phase resulted in even greater SOA concentrations as a result of a positive feedback in which water uptake increased SOA, which further increased aerosol water and organic aerosol. Aerosol properties, such as the OM / OC and hygroscopicity parameter (κorg), were captured well by the model compared with measurements during the Southern Oxidant and Aerosol Study (SOAS) 2013. Organic nitrates from monoterpene oxidation were predicted to be the least water-soluble semivolatile species in the model, but most biogenically derived semivolatile species in the Community Multiscale Air Quality (CMAQ) model were highly water soluble and expected to contribute to water-soluble organic carbon (WSOC). Organic aerosol and SOA precursors were abundant at night, but additional improvements in daytime organic aerosol are needed to close the model-measurement gap. When taking into account deviations from ideality, including both inorganic (when RH > SRH) and organic water in the organic partitioning medium reduced the mean bias in SOA for routine monitoring networks and improved model performance compared to observations from SOAS. Property updates from

  16. Chemical Reactivity and Liquid/Nonliquid States of Secondary Organic Material.

    PubMed

    Li, Yong Jie; Liu, Pengfei; Gong, Zhaoheng; Wang, Yan; Bateman, Adam P; Bergoend, Clara; Bertram, Allan K; Martin, Scot T

    2015-11-17

    The reactivity of secondary organic material (SOM) of variable viscosity, ranging from nonliquid to liquid physical states, was studied. The SOM, produced in aerosol form from terpenoid and aromatic precursor species, was reacted with ammonia at variable relative humidity (RH). The ammonium-to-organic mass ratio (MNH4+/MOrg) increased monotonically from <5% RH to a limiting value at a threshold RH, implicating a transition from particle reactivity limited by diffusion at low RH to one limited by other factors at higher RH. For the studied size distributions and reaction times, the transition corresponded to a diffusivity above 10-17.5 ± 0.5 m2 s-1. The threshold RH values for the transition were <5% RH for isoprene-derived SOM, 35-45% RH for SOM derived from α-pinene, toluene, m-xylene, and 1,3,5-trimethylbenzene, and >90% for β-caryophyllene-derived SOM. The transition RH for reactivity differed in all cases from the transition RH of a nonliquid to a liquid state. For instance, for α-pinene-derived SOM the transition for chemical reactivity of 35-45% RH can be compared to the nonliquid to liquid transition of 65-90% RH. These differences imply that chemical transport models of atmospheric chemistry should not use the SOM liquid to nonliquid phase transition as one-to-one surrogates of SOM reactivity.

  17. Response of organic liquid scintillators to fast neutrons and gamma radiation

    NASA Astrophysics Data System (ADS)

    Hoertz, Paul G.; Mills, Karmann; Davis, Lynn; Baldasaro, Nicholas; Gupta, Vijay

    2013-03-01

    Liquid organic scintillators are cocktails of aromatic fluorophores in an aromatic solvent. They find widespread use in Liquid Scintillation Counters with applications in medical diagnostics as well as fundamental nuclear and particle physics. Ultima Gold™ XR, a commercially available organic liquid scintillator from Perkin Elmer, can be used in both aqueous and non-aqueous systems and is typically used for beta detection in medical diagnostics. Its performance under gamma radiation and neutron radiation is less well-characterized. Special and normal Ultima Gold™ XR liquid scintillators were exposed in separate experiments to fast neutrons and high energy photons from a nuclear reactor and to gamma rays from a Co-60 source. To perform the measurements in the radiation chamber, a custom light collection system consisting of a fiber optic cable, spectrometer and a diffuse reflecting optical cavity was fabricated. Advanced calibration procedures, traceable to NIST standards, were developed to determine photon fluxes and flux densities of the scintillators under ionizing radiation conditions. The scintillator emission spectra under gamma radiation from a Co-60 source and neutron radiation from a pool-type nuclear reactor were recorded and compared. Results on the spectrometer design and comparison of the spectra under different exposure are presented.

  18. Nondisruptive Dissolution of Hyperpolarized 129 Xe into Viscous Aqueous and Organic Liquid Crystalline Environments

    SciTech Connect

    Truxal, Ashley E.; Slack, Clancy C.; Gomes, Muller D.; Vassiliou, Christophoros C.; Wemmer, David E.; Pines, Alexander

    2016-03-08

    Studies of hyperpolarized xenon-129 in media such as liquid crystals and cell suspensions are in demand for applications ranging from biomedical imaging to materials engineering but have been hindered by the inability to bubble Xe through the desired media as a result of viscosity or perturbations caused by bubbles. This research reports on a device that can be reliably used to dissolve hp- 129 Xe into viscous aqueous and organic samples without bubbling. This method is robust, requires small sample volumes ( < 60 μL), is compatible with existing NMR hardware, and is made from readily available materials. Experiments show that Xe can be introduced into viscous and aligned media without disrupting molecular order. We detected dissolved xenon in an aqueous liquid crystal that is disrupted by the shear forces of bubbling, and we observed liquid-crystal phase transitions in (MBBA). This tool allows an entirely new class of samples to be investigated by hyperpolarized-gas NMR spectroscopy. Blending into the crowd: A new device that facilitates the direct dissolution of hyperpolarized 129 Xe into viscous liquid-crystalline media is presented. 129 Xe and 2 H NMR spectra show the nondisruptive dissolution of xenon, the presence of ordered phases, and, in the case of the thermotropic liquid crystal N-(4-methoxybenzylidene)-4-butylaniline, a nematic-isotropic phase transition.

  19. Low-voltage operation of n-type organic field-effect transistors with ionic liquid

    NASA Astrophysics Data System (ADS)

    Uemura, T.; Yamagishi, M.; Ono, S.; Takeya, J.

    2009-09-01

    High performance n-type organic field-effect transistors are developed to achieve high transconductance and low-threshold voltage using ionic-liquid electrolyte for intense electrostatic gating. Tetracyanoquinodimethane single crystals and C60 thin films are interfaced with ionic liquid of 1-ethyl-3-methyl-imidazolium bis(trifluoromethanesulfonyl)imide known for its low viscosity and high ionic conductivity, so that high-density electrons are rapidly accumulated in the semiconductor surfaces with the application of minimum gate voltages, forming 1-nm thick electric double layers to concentrate electric field as high as 1 MV/cm. The C60 transistor shows the highest normalized transconductance among reported n-type organic transistors, together with minimum threshold voltage.

  20. Liquid crystal-based Mueller matrix spectral imaging polarimetry for parameterizing mineral structural organization.

    PubMed

    Gladish, James C; Duncan, Donald D

    2017-01-20

    Herein, we discuss the remote assessment of the subwavelength organizational structure of a medium. Specifically, we use spectral imaging polarimetry, as the vector nature of polarized light enables it to interact with optical anisotropies within a medium, while the spectral aspect of polarization is sensitive to small-scale structure. The ability to image these effects allows for inference of spatial structural organization parameters. This work describes a methodology for revealing structural organization by exploiting the Stokes/Mueller formalism and by utilizing measurements from a spectral imaging polarimeter constructed from liquid crystal variable retarders and a liquid crystal tunable filter. We provide results to validate the system and then show results from measurements on a mineral sample.

  1. Effectiveness of Operation of Organic Rankine Cycle Installation Applied in the Liquid Natural Gas Regasification Plant

    NASA Astrophysics Data System (ADS)

    Kaczmarek, R.; Stachel, A. A.

    2017-05-01

    An analysis of the operation of an Organic Rankine Cycle (ORC) installation heated by a low-temperature heat source is presented for the case where a condenser of a working fluid is cooled by a liquid of ultralow temperature. For this purpose, the process of regasification of liquid natural gas (LNG) is considered. In the process, the condensation heat of the working fluid in ORC is taken by the LNG evaporating subsequently (i.e., undergoing regasification). The paper presents the schematic of this installation and its application, as well as the results of calculations on the basis of the analysis in terms of the power and efficiency. In the analysis, organic fluids used in the ORC as working ones have been selected.

  2. A novel liquid organic hydrogen carrier system based on catalytic peptide formation and hydrogenation

    PubMed Central

    Hu, Peng; Fogler, Eran; Diskin-Posner, Yael; Iron, Mark A.; Milstein, David

    2015-01-01

    Hydrogen is an efficient green fuel, but its low energy density when stored under high pressure or cryogenically, and safety issues, presents significant disadvantages; hence finding efficient and safe hydrogen carriers is a major challenge. Of special interest are liquid organic hydrogen carriers (LOHCs), which can be readily loaded and unloaded with considerable amounts of hydrogen. However, disadvantages include high hydrogen pressure requirements, high reaction temperatures for both hydrogenation and dehydrogenation steps, which require different catalysts, and high LOHC cost. Here we present a readily reversible LOHC system based on catalytic peptide formation and hydrogenation, using an inexpensive, safe and abundant organic compound with high potential capacity to store and release hydrogen, applying the same catalyst for loading and unloading hydrogen under relatively mild conditions. Mechanistic insight of the catalytic reaction is provided. We believe that these findings may lead to the development of an inexpensive, safe and clean liquid hydrogen carrier system. PMID:25882348

  3. A novel liquid organic hydrogen carrier system based on catalytic peptide formation and hydrogenation.

    PubMed

    Hu, Peng; Fogler, Eran; Diskin-Posner, Yael; Iron, Mark A; Milstein, David

    2015-04-17

    Hydrogen is an efficient green fuel, but its low energy density when stored under high pressure or cryogenically, and safety issues, presents significant disadvantages; hence finding efficient and safe hydrogen carriers is a major challenge. Of special interest are liquid organic hydrogen carriers (LOHCs), which can be readily loaded and unloaded with considerable amounts of hydrogen. However, disadvantages include high hydrogen pressure requirements, high reaction temperatures for both hydrogenation and dehydrogenation steps, which require different catalysts, and high LOHC cost. Here we present a readily reversible LOHC system based on catalytic peptide formation and hydrogenation, using an inexpensive, safe and abundant organic compound with high potential capacity to store and release hydrogen, applying the same catalyst for loading and unloading hydrogen under relatively mild conditions. Mechanistic insight of the catalytic reaction is provided. We believe that these findings may lead to the development of an inexpensive, safe and clean liquid hydrogen carrier system.

  4. Basic technology for 6Li enrichment using an ionic-liquid impregnated organic membrane

    NASA Astrophysics Data System (ADS)

    Hoshino, Tsuyoshi; Terai, Takayuki

    2011-10-01

    The tritium needed as a fuel for fusion reactors is produced by the neutron capture reaction of lithium-6 ( 6Li) in tritium breeding materials. However, natural Li contains only about 7.6 at.% 6Li. 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 6Li separation coefficient and the applied electrodialytic conditions was evaluated using them. The results showed that the 6Li isotope separation coefficient in this method (about 1.1-1.4) was larger than that in the mercury amalgam method (about 1.06).

  5. Self-organized liquid-crystalline nanostructured membranes for water treatment: selective permeation of ions.

    PubMed

    Henmi, Masahiro; Nakatsuji, Koji; Ichikawa, Takahiro; Tomioka, Hiroki; Sakamoto, Takeshi; Yoshio, Masafumi; Kato, Takashi

    2012-05-02

    A membrane with ordered 3D ionic nanochannels constructed by in situ photopolymerization of a thermotropic liquid-crystalline monomer shows high filtration performance and ion selectivity. The nanostructured membrane exhibits water-treatment performance superior to that of an amorphous membrane prepared from the isotropic melt of the monomer. Self-organized nanostructured membranes have great potential for supplying high-quality water. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Technical Assessment of Organic Liquid Carrier Hydrogen Storage Systems for Automotive Applications

    SciTech Connect

    Ahluwalia, R. K.; Hua, T. Q.; Peng, J. -K; Kromer, M.; Lasher, S.; McKenney, K.; Law, K.; Sinha, J.

    2011-06-21

    In 2007-2009, the DOE Hydrogen Program conducted a technical assessment of organic liquid carrier based hydrogen storage systems for automotive applications, consistent with the Program’s Multiyear Research, Development, and Demonstration Plan. This joint performance (ANL) and cost analysis (TIAX) report summarizes the results of this assessment. These results should be considered only in conjunction with the assumptions used in selecting, evaluating, and costing the systems discussed here and in the Appendices.

  7. Metal-organic frameworks as host materials of confined supercooled liquids.

    PubMed

    Fischer, J K H; Sippel, P; Denysenko, D; Lunkenheimer, P; Volkmer, D; Loidl, A

    2015-10-21

    In this work, we examine the use of metal-organic framework (MOF) systems as host materials for the investigation of glassy dynamics in confined geometry. We investigate the confinement of the molecular glass former glycerol in three MFU-type MOFs with different pore sizes (MFU stands for "Metal-Organic Framework Ulm-University") and study the dynamics of the confined liquid via dielectric spectroscopy. In accord with previous reports on confined glass formers, we find different degrees of deviations from bulk behavior depending on pore size, demonstrating that MOFs are well-suited host systems for confinement investigations.

  8. Metal-organic frameworks as host materials of confined supercooled liquids

    NASA Astrophysics Data System (ADS)

    Fischer, J. K. H.; Sippel, P.; Denysenko, D.; Lunkenheimer, P.; Volkmer, D.; Loidl, A.

    2015-10-01

    In this work, we examine the use of metal-organic framework (MOF) systems as host materials for the investigation of glassy dynamics in confined geometry. We investigate the confinement of the molecular glass former glycerol in three MFU-type MOFs with different pore sizes (MFU stands for "Metal-Organic Framework Ulm-University") and study the dynamics of the confined liquid via dielectric spectroscopy. In accord with previous reports on confined glass formers, we find different degrees of deviations from bulk behavior depending on pore size, demonstrating that MOFs are well-suited host systems for confinement investigations.

  9. Insights into Mechanistic Models for Evaporation of Organic Liquids in the Environment Obtained by Position-Specific Carbon Isotope Analysis.

    PubMed

    Julien, Maxime; Nun, Pierrick; Robins, Richard J; Remaud, Gérald S; Parinet, Julien; Höhener, Patrick

    2015-11-03

    Position-specific isotope effects (PSIEs) have been measured by isotope ratio monitoring (13)C nuclear magnetic resonance spectrometry during the evaporation of 10 liquids of different polarities under 4 evaporation modes (passive evaporation, air-vented evaporation, low pressure evaporation, distillation). The observed effects are used to assess the validity of the Craig-Gordon isotope model for organic liquids. For seven liquids the overall isotope effect (IE) includes a vapor-liquid contribution that is strongly position-specific in polar compounds but less so in apolar compounds and a diffusive IE that is not position-specific, except in the alcohols, ethanol and propan-1-ol. The diffusive IE is diminished under forced evaporation. The position-specific isotope pattern created by liquid-vapor IEs is manifest in five liquids, which have an air-side limitation for volatilization. For the alcohols, undefined processes in the liquid phase create additional PSIEs. Three other liquids with limitations on the liquid side have a lower, highly position-specific, bulk diffusive IE. It is concluded that evaporation of organic pollutants creates unique position-specific isotope patterns that may be used to assess the progress of remediation or natural attenuation of pollution and that the Craig-Gordon isotope model is valid for the volatilization of nonpolar organic liquids with air-side limitation of the volatilization rate.

  10. Comparison of dispersive liquid-liquid microextraction based on organic solvent and ionic liquid combined with high-performance liquid chromatography for the analysis of emodin and its metabolites in urine samples.

    PubMed

    Tian, Jie; Chen, Xuan; Bai, Xiaohong

    2012-01-01

    In this paper, two methods based on organic solvent dispersive liquid-liquid microextraction (OS-DLLME) and ionic liquid dispersive liquid-liquid microextraction (IL-DLLME) coupled with high-performance liquid chromatography have been critically compared for analyzing emodin and its metabolites (aloe-emodin, anthraquinone-2-carboxylic acid, rhein, danthron, chrysophanol and physcion) in urine samples. Several important parameters influencing the extraction recoveries of DLLME were carefully optimized. Under optimal conditions, the enrichment factors (EFs) for emodin and its metabolites by OS-DLLME and IL-DLLME were within the range of 90-295 and 63-192 respectively; the relative standard deviations (RSDs, n=3) for intra-day and inter-day precision were lower than 7.2 and 8.7% by OS-DLLME, and lower than 5.7 and 6.4% by IL-DLLME; the recoveries of emodin and its metabolites were from 87.1 to 105% for OS-DLLME and from 94.8 to 103% for IL-DLLME, respectively. There were no significant deviations between the two methods for the determination of emodin and its metabolites. From the results of HPLC/UV of urine sample after DLLME, the metabolites aloe-emodin, rhein, chrysophanol and physcion were identified by comparing the retention times with the standards. From the results of HPLC/MS, anthraquinone-2-carboxylic acid and danthron as unreported metabolites of emodin were found.

  11. Parameterizing liquid crystal variable retarder structural organization with a fractal-Born approximation model

    NASA Astrophysics Data System (ADS)

    Gladish, James C.; Duncan, Donald D.

    2016-05-01

    Liquid crystal variable retarders (LCVRs) are computer-controlled birefringent devices that contain nanometer-sized birefringent liquid crystals (LCs). These devices impart retardance effects through a global, uniform orientation change of the LCs, which is based on a user-defined drive voltage input. In other words, the LC structural organization dictates the device functionality. The LC structural organization also produces a spectral scatter component which exhibits an inverse power law dependence. We investigate LC structural organization by measuring the voltage-dependent LC spectral scattering signature with an integrating sphere and then relate this observable to a fractal-Born model based on the Born approximation and a Von Kármán spectrum. We obtain LCVR light scattering spectra at various drive voltages (i.e., different LC orientations) and then parameterize LCVR structural organization with voltage-dependent correlation lengths. The results can aid in determining performance characteristics of systems using LCVRs and can provide insight into interpreting structural organization measurements.

  12. Capabilities and limitations of dispersive liquid-liquid microextraction with solidification of floating organic drop for the extraction of organic pollutants from water samples.

    PubMed

    Vera-Avila, Luz E; Rojo-Portillo, Tania; Covarrubias-Herrera, Rosario; Peña-Alvarez, Araceli

    2013-12-17

    Dispersive liquid-liquid microextraction with solidification of floating organic drop (DLLME-SFO) is one of the most interesting sample preparation techniques developed in recent years. Although several applications have been reported, the potentiality and limitations of this simple and rapid extraction technique have not been made sufficiently explicit. In this work, the extraction efficiency of DLLME-SFO for pollutants from different chemical families was determined. Studied compounds include: 10 polycyclic aromatic hydrocarbons, 5 pesticides (chlorophenoxy herbicides and DDT), 8 phenols and 6 sulfonamides, thus, covering a large range of polarity and hydrophobicity (LogKow 0-7, overall). After optimization of extraction conditions using 1-dodecanol as extractant, the procedure was applied for extraction of each family from 10-mL spiked water samples, only adjusting sample pH as required. Absolute recoveries for pollutants with LogKow 3-7 were >70% and recovery values within this group (18 compounds) were independent of structure or hydrophobicity; the precision of recovery was very acceptable (RSD<12%) and linear behavior was observed in the studied concentration range (r(2)>0.995). Extraction recoveries for pollutants with LogKow 1.46-2.8 were in the range 13-62%, directly depending on individual LogKow values; however, good linearity (r(2)>0.993) and precision (RSD<6.5%) were also demonstrated for these polar solutes, despite recovery level. DLLME-SFO with 1-dodecanol completely failed for extraction of compounds with LogKow≤1 (sulfa drugs), other more polar extraction solvents (ionic liquids) should be explored for highly hydrophilic pollutants. Copyright © 2013 Elsevier B.V. All rights reserved.

  13. Hygroscopic influence on the semisolid-to-liquid transition of secondary organic materials.

    PubMed

    Bateman, Adam P; Bertram, Allan K; Martin, Scot T

    2015-05-14

    The effect of relative humidity (RH) on the rebound of particles composed of isoprene, α-pinene, and toluene secondary organic materials (SOMs) was studied. A three-arm impaction apparatus was used to study rebound from 5 to 95% RH at 298 K. Calibration experiments using sucrose particles of variable but known viscosities showed that the transition from rebounding to adhering particles occurred for a change in viscosity from 100 to 1 Pa s, corresponding to a transition from semisolid to liquid material. The experimentally determined rebound fractions of the studied SOMs were compared with results from a model of the rebound processes of hard particles, taking into account the particle kinetic energy, van der Waals forces, and RH-dependent capillary forces. For low RH values, the hard-particle model explained the diameter-dependent rebound behavior for all studied SOMs. For elevated RH, however, the experimental observations deviated from the model predictions. On the basis of the calibration experiments using sucrose particles as well as a comparison between the observations and the predictions of the hard-particle model, the interpretation is made that a semisolid-to-liquid transition occurred at elevated RH. Material softening, increased adhesion, or a combination of the two implied the action of additional modes of energy relaxation that were not included in the hard-particle model. The RH threshold for the semisolid-to-liquid phase transition was 40% RH for isoprene SOM, 70% for toluene SOM, and 70% for α-pinene SOM. A correlation between the rebound fraction and the hygroscopic growth factor G was demonstrated, implying that absorbed water volume was a dominant governing factor of the semisolid-to-liquid transition for the studied classes of SOM. Simple heuristic rules based on G of 1.15 for the semisolid-to-liquid phase transition could be used for prognostication of the SOM phase in modeling applications at 298 K. With respect to atmospheric processes, the

  14. Study of the analytical methods for iron determination in complex organic liquids by atomic absorption spectrometry

    SciTech Connect

    Torre, M.; Gonzalez, M.C.; Jimenez, O.; Rodriquez, A.R. )

    1990-01-01

    In the determination of iron in complex organic liquids by atomic absorption spectrometry (A.A.S.), methods of sample preparation, such as dilution with an organic solvent and sample pretreatment to destroy organic material, are investigated. Moreover, methods of analysis using calibration curve and standard additions are presented. The possible cause of error associated with iron determination in organic samples by flame (F-A.A.S.) and graphite furnace (GF-A.A.S.) atomic absorption spectrometry are discussed. From all of these studies, the use of graphite furnace atomic absorption spectrometry after sample dilution with methyl isobutyl ketone, and the use of the method of standard additions are advised for iron determination.

  15. Greenhouse Gas Emissions from Solid and Liquid Organic Fertilizers Applied to Lettuce.

    PubMed

    Toonsiri, Phasita; Del Grosso, Stephen J; Sukor, Arina; Davis, Jessica G

    2016-11-01

    Improper application of nitrogen (N) fertilizer and environmental factors can cause the loss of nitrous oxide (NO) to the environment. Different types of fertilizers with different C/N ratios may have different effects on the environment. The focus of this study was to evaluate the effects of environmental factors and four organic fertilizers (feather meal, blood meal, fish emulsion, and cyano-fertilizer) applied at different rates (0, 28, 56, and 112 kg N ha) on NO emissions and to track CO emissions from a lettuce field ( L.). The study was conducted in 2013 and 2014 and compared preplant-applied solid fertilizers (feather meal and blood meal) and multiple applications of liquid fertilizers (fish emulsion and cyano-fertilizer). Three days a week, NO and CO emissions were measured twice per day in 2013 and once per day in 2014 using a closed-static chamber, and gas samples were analyzed by gas chromatography. Preplant-applied solid fertilizers significantly increased cumulative NO emissions as compared with control, but multiple applications of liquid fertilizers did not. Emission factors for NO ranged from 0 to 0.1% for multiple applications of liquid fertilizers and 0.6 to 11% for preplant-applied solid fertilizers, which could be overestimated due to chamber placement over fertilizer bands. In 2014, solid fertilizers with higher C/N ratios (3.3-3.5) resulted in higher CO emissions than liquid fertilizers (C/N ratio, 0.9-1.5). Therefore, organic farmers should consider the use of multiple applications of liquid fertilizers as a means to reduce soil greenhouse gas emissions while maintaining high yields. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  16. Genotoxicity, mutagenicity and cytotoxicity of carotenoids extracted from ionic liquid in multiples organs of Wistar rats.

    PubMed

    Larangeira, Paula Martins; de Rosso, Veridiana Vera; da Silva, Victor Hugo Pereira; de Moura, Carolina Foot Gomes; Ribeiro, Daniel Araki

    2016-11-01

    The ionic liquid or melted salt 1-Butyl-3-methylimidazolium is an alternative process to extract natural pigments, such as carotenoids. Lycopene represents 80-90% of total of carotenoids presents in tomatoes and it has been widely studied due its potent antioxidant action. The aim of this study was to evaluate genotoxicity, mutagenicity and cytotoxicity of carotenoids extracted from ionic liquid using experimental model in vivo. For this purpose, a total of 20 male Wistar rats were distributed into four groups (n=5), as follows: control group; received a corresponding amount of corn oil for 7days by intragastric gavage (i.g.), ionic liquid group, received 10mgkg(-1) body weight for 7days by gavage; 10mg carotenoids group, received 10mgkg(-1) bw dissolved in corn oil for 7days by gavage and 500mg carotenoids group, received 500mgkg(-1) bw dissolved in corn oil for 7days by gavage. Rat liver treated with ionic liquid exhibited moderate histopathological changes randomly distributed in the parenchyma, such as cytoplasmic eosinophilia, apoptotic bodies, inflammatory infiltrate and focal necrosis. DNA damage was found in peripheral blood and liver cells of rats treated with ionic liquid or carotenoids at 500mg. An increase of micronucleated cells and 8-OhDG immunopositive cells were also detected in rats treated with carotenoids at 500mg. In summary, our results demonstrate that recommended dose for human daily intake of carotenoids extracted by ionic liquid did not induce genotoxicity, mutagenicity and cytotoxicity in multiple organs of rats. Copyright © 2016 Elsevier GmbH. All rights reserved.

  17. Chromatographic behavior of small organic compounds in low-temperature high-performance liquid chromatography using liquid carbon dioxide as the mobile phase.

    PubMed

    Motono, Tomohiro; Nagai, Takashi; Kitagawa, Shinya; Ohtani, Hajime

    2015-07-01

    Low-temperature high-performance liquid chromatography, in which a loop injector, column, and detection cell were refrigerated at -35ºC, using liquid carbon dioxide as the mobile phase was developed. Small organic compounds (polyaromatic hydrocarbons, alkylbenzenes, and quinones) were separated by low-temperature high-performance liquid chromatography at temperatures from -35 to -5ºC. The combination of liquid carbon dioxide mobile phase with an octadecyl-silica (C18 ) column provided reversed phase mode separation, and a bare silica-gel column resulted in normal phase mode separation. In both the cases, nonlinear behavior at approximately -15ºC was found in the relationship between the temperature and the retention factors of the analytes (van't Hoff plots). In contrast to general trends in high-performance liquid chromatography, the decrease in temperature enhanced the separation efficiency of both the columns.

  18. Ionic liquids as an electrolyte for the electro synthesis of organic compounds.

    PubMed

    Kathiresan, Murugavel; Velayutham, David

    2015-12-25

    The use of ionic liquids (ILs) as a solvent and an electrolyte for electro organic synthesis has been reviewed. To date several ILs exist, however the ILs based on tetraalkylammonium, pyrrolidinium, piperidinium and imidazolium cations with BF4(-), PF6(-), and TFSI anions have been widely used and explored the most. Electro organic synthesis in ionic liquid media leading to the synthesis of a wide range of organic compounds has been discussed. Anodic oxidation or cathodic reduction will generate radical cation or anion intermediates, respectively. These radicals can undergo self coupling or coupling with other molecules yielding organic compounds of interest. The cation of the IL is known to stabilize the radical anion extensively. This stabilization effect has a specific impact on the electrochemical CO2 reduction and coupling to various organics. The relative stability of the intermediates in IL leads to the formation of specific products in higher yields. Electrochemical reduction of imidazolium or thiazolium based ILs generates N-heterocyclic carbenes that have been shown to catalyze a wide range of base or nucleophile catalyzed organic reactions in IL media, an aspect that falls into the category of organocatalysis. Electrochemical fluorination or selective electrochemical fluorination is another fascinating area that delivers selectively fluorinated organic products in Et3N·nHF or Et4NF·nHF adducts (IL) via anodic oxidation. Oxidative polymerization in ILs has been explored the most; although morphological changes were observed compared to the conventional methods, polymers were obtained in good yields and in some cases ILs were used as dopants to improve the desired properties.

  19. Utilizing liquid crystal phases to obtain highly ordered thin films for organic electronics

    NASA Astrophysics Data System (ADS)

    Springer, Mike T.

    Organic electronic materials offer several advantages when compared to inorganic materials, but they suffer from low charge carrier mobility. Two major factors hindering effective charge transport in organic materials are: 1) effective wavefunction overlap in organic crystals and 2) the domain morphology of thin films. Charge transport in organic materials occurs via a hopping mechanism along the conjugated pi system. Often, rigid, aromatic organic materials crystallize in a herringbone, edge-to-face orientation, limiting pi-pi stacking and decreasing charge carrier mobility. Face-to-face orientation of aromatic rings decreases intermolecular pi-pi distances and increases wavefunction overlap. Control of the crystal structure can be achieved to some extent by tuning structural features of the molecule, like increasing the ratio of carbon atoms to hydrogen atoms in the aromatic rings; this is often achieved by introducing heteroatoms like sulfur and oxygen into the aromatic ring structure. Thin films of organic materials often contain many unaligned domains; this is caused by rapid crystallization. Control of the domain morphology of thin films has been shown to increase charge carrier mobility by 6 orders of magnitude for thin films of the same material. Liquid crystal phases allow a slow process of crystallization, whereby the molecules in a thin film can be slowly aligned into a monodomain before crystallization. The crystal-smectic phases, like smectic E, are particularly attractive for this strategy due to their high degree of intermolecular order. This project describes the synthesis and characterization of organic semiconductors designed to exhibit short pi-pi distances and highly ordered crystal-smectic phases to obtain thin films with high charge carrier mobility. The n,2-OBTTT series contains 15 newly designed and synthesized mesogens. The liquid crystal and solid crystal structures of these mesogens are examined and deposition conditions are optimized for

  20. Pyrolysis characteristics and pyrolysis products separation for recycling organic materials from waste liquid crystal display panels.

    PubMed

    Wang, Ruixue; Xu, Zhenming

    2016-01-25

    Waste liquid crystal display (LCD) panels mainly contain inorganic materials (glass substrate with indium-tin oxide film), and organic materials (polarizing film and liquid crystal). The organic materials should be removed beforehand since the organic matters would hinder the indium recycling process. In the present study, pyrolysis process is used to remove the organic materials and recycle acetic as well as and triphenyl phosphate (TPP) from waste LCD panels in an environmental friendly way. Several highlights of this study are summarized as follows: (i) Pyrolysis characteristics and pyrolysis kinetics analysis are conducted which is significant to get a better understanding of the pyrolysis process. (ii) Optimum design is developed by applying Box-Behnken Design (BBD) under response surface methodology (RSM) for engineering application which is significant to guide the further industrial recycling process. The oil yield could reach 70.53 wt% and the residue rate could reach 14.05 wt% when the pyrolysis temperature is 570 °C, nitrogen flow rate is 6 L min(-1) and the particle size is 0.5 mm. (iii) Furthermore, acetic acid and TPP are recycled, and then separated by rotary evaporation, which could reduce the consumption of fossil energy for producing acetic acid, and be reused in electronics manufacturing industry. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Ionic Liquids Beyond Simple Solvents: Glimpses at the State of the Art in Organic Chemistry

    PubMed Central

    Kuchenbuch, Andrea

    2015-01-01

    Abstract Within the last 25 years ionic liquids have written a tremendous success story, which is documented in a nearly uncountable amount of original research papers, reviews, and numerous applications in research and industry. These days, ionic liquids can be considered as a mature class of compounds for many different applications. Frequently, they are used as neoteric solvents for chemical tansformations, and the number of reviews on this field of research is huge. In this focused review, though, we are trying to evaluate the state of the art of ionic liquid chemistry beyond using them simply as solvents for chemical transformations. It is not meant to be a comprehensive overview on the topic; the choice of emphasis and examples rather refects the authors’ personal view on the field. We are especially highlighting fields in which we believe the most fundamental developments within the next five years will take place: biomass processing, (chiral) ionic liquids from natural sources, biotransformations, and organic synthesis. PMID:27308192

  2. Improved solvent collection system for a dispersive liquid-liquid microextraction of organochlorine pesticides from water using low-density organic solvent.

    PubMed

    Chang, Chu-Chi; Wei, Shuo-Yang; Huang, Shang-Da

    2011-04-01

    In this study, the organochlorine pesticides (OCPs) levels in lake and tap water samples were determined by a dispersive liquid-liquid microextraction method using a low-density organic solvent and an improved solvent collection system (DLLME-ISCS). This method used a very small volume of a solvent of low toxicity (11  μL of 1-nonanol and 400  μL of methanol) to extract OCPs from 10  mL water samples prior to the analysis by GC. After centrifugation in the dispersive liquid-liquid microextraction, there was a liquid organic drop floating between the water surface and the glass wall of the centrifuge tube. The liquid organic drop (with some water phase) was transferred into a microtube (3  mm×15  mm) with a syringe. The organic and aqueous phases were separated in the microtube immediately. Then, 1  μL of the organic solvent (which was in the upper portion of liquid in the microtube) was easily collected by a syringe and injected into the GC-ECD system for the analysis. Under optimum conditions, the linear range of this method was 5-5000  ng/L for most of the analytes. The correlation coefficient was higher than 0.997. Enrichment factors ranged from 1309 to 3629. The relative recoveries ranged from 73 to 119% for lake water samples. The LODs of the method ranged from 0.7 to 9.4  ng/L. The precision of the method ranged from 1.0 to 10.8% for lake water.

  3. The electro-structural behaviour of yarn-like carbon nanotube fibres immersed in organic liquids

    NASA Astrophysics Data System (ADS)

    Terrones, Jeronimo; Windle, Alan H.; Elliott, James A.

    2014-10-01

    Yarn-like carbon nanotube (CNT) fibres are a hierarchically-structured material with a variety of promising applications such as high performance composites, sensors and actuators, smart textiles, and energy storage and transmission. However, in order to fully realize these possibilities, a more detailed understanding of their interactions with the environment is required. In this work, we describe a simplified representation of the hierarchical structure of the fibres from which several mathematical models are constructed to explain electro-structural interactions of fibres with organic liquids. A balance between the elastic and surface energies of the CNT bundle network in different media allows the determination of the maximum lengths that open junctions can sustain before collapsing to minimize the surface energy. This characteristic length correlates well with the increase of fibre resistance upon immersion in organic liquids. We also study the effect of charge accumulation in open interbundle junctions and derive expressions to describe experimental data on the non-ohmic electrical behaviour of fibres immersed in polar liquids. Our analyses suggest that the non-ohmic behaviour is caused by progressively shorter junctions collapsing as the voltage is increased. Since our models are not based on any property unique to carbon nanotubes, they should also be useful to describe other hierarchical structures.

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

    NASA Astrophysics Data System (ADS)

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

    2016-08-01

    Freezing can affect concentrations and spectroscopic properties of dissolved organic matter (DOM) in water samples. Nevertheless, water samples are regularly frozen for sample preservation. In this study we tested the effect of different freezing methods (standard freezing at -18 °C and fast-freezing with liquid nitrogen) on DOM concentrations measured as organic carbon (DOC) concentrations and on spectroscopic properties of DOM from different terrestrial ecosystems (forest and grassland). Fresh and differently frozen throughfall, stemflow, litter leachate and soil solution samples were analyzed for DOC concentrations, UV-vis absorption and fluorescence excitation-emission matrices combined with parallel factor analysis (PARAFAC). Fast-freezing with liquid nitrogen prevented a significant decrease of DOC concentrations observed after freezing at -18 °C. Nonetheless, the share of PARAFAC components 1 (EXmax < 250 nm (340 nm), EXmax: 480 nm) and 2 (EXmax: 335 nm, EXmax: 408 nm) to total fluorescence and the humification index (HIX) decreased after both freezing treatments, while the shares of component 3 (EXmax: < 250 nm (305 nm), EXmax: 438 nm) as well as SUVA254 increased. The contribution of PARAFAC component 4 (EXmax: 280 nm, EXmax: 328 nm) to total fluorescence was not affected by freezing. We recommend fast-freezing with liquid nitrogen for preservation of bulk DOC concentrations of samples from terrestrial sources, whereas immediate measuring is preferable to preserve spectroscopic properties of DOM.

  5. The electro-structural behaviour of yarn-like carbon nanotube fibres immersed in organic liquids

    PubMed Central

    Terrones, Jeronimo; Windle, Alan H; Elliott, James A

    2014-01-01

    Yarn-like carbon nanotube (CNT) fibres are a hierarchically-structured material with a variety of promising applications such as high performance composites, sensors and actuators, smart textiles, and energy storage and transmission. However, in order to fully realize these possibilities, a more detailed understanding of their interactions with the environment is required. In this work, we describe a simplified representation of the hierarchical structure of the fibres from which several mathematical models are constructed to explain electro-structural interactions of fibres with organic liquids. A balance between the elastic and surface energies of the CNT bundle network in different media allows the determination of the maximum lengths that open junctions can sustain before collapsing to minimize the surface energy. This characteristic length correlates well with the increase of fibre resistance upon immersion in organic liquids. We also study the effect of charge accumulation in open interbundle junctions and derive expressions to describe experimental data on the non-ohmic electrical behaviour of fibres immersed in polar liquids. Our analyses suggest that the non-ohmic behaviour is caused by progressively shorter junctions collapsing as the voltage is increased. Since our models are not based on any property unique to carbon nanotubes, they should also be useful to describe other hierarchical structures. PMID:27877720

  6. The electro-structural behaviour of yarn-like carbon nanotube fibres immersed in organic liquids.

    PubMed

    Terrones, Jeronimo; Windle, Alan H; Elliott, James A

    2014-10-01

    Yarn-like carbon nanotube (CNT) fibres are a hierarchically-structured material with a variety of promising applications such as high performance composites, sensors and actuators, smart textiles, and energy storage and transmission. However, in order to fully realize these possibilities, a more detailed understanding of their interactions with the environment is required. In this work, we describe a simplified representation of the hierarchical structure of the fibres from which several mathematical models are constructed to explain electro-structural interactions of fibres with organic liquids. A balance between the elastic and surface energies of the CNT bundle network in different media allows the determination of the maximum lengths that open junctions can sustain before collapsing to minimize the surface energy. This characteristic length correlates well with the increase of fibre resistance upon immersion in organic liquids. We also study the effect of charge accumulation in open interbundle junctions and derive expressions to describe experimental data on the non-ohmic electrical behaviour of fibres immersed in polar liquids. Our analyses suggest that the non-ohmic behaviour is caused by progressively shorter junctions collapsing as the voltage is increased. Since our models are not based on any property unique to carbon nanotubes, they should also be useful to describe other hierarchical structures.

  7. 3D Spin-Liquid State in an Organic Hyperkagome Lattice of Mott Dimers

    NASA Astrophysics Data System (ADS)

    Mizuno, Asato; Shuku, Yoshiaki; Matsushita, Michio M.; Tsuchiizu, Masahisa; Hara, Yuuki; Wada, Nobuo; Shimizu, Yasuhiro; Awaga, Kunio

    2017-08-01

    We report the first 3D spin liquid state of isotropic organic spins. Structural analysis, and magnetic and heat-capacity measurements were carried out for a chiral organic radical salt, (TBA) 1.5[(-)-NDI -Δ ] (TBA denotes tetrabutylammonium and NDI denotes naphthalene diimide), in which (-)-NDI -Δ forms a K4 structure due to its triangular molecular structure and an intermolecular π -π overlap between the NDI moieties. This lattice was identical to the hyperkagome lattice of S =1 /2 Mott dimers, and should exhibit 3D spin frustration. In fact, even though the high-temperature magnetic susceptibility followed the Curie-Weiss law with a negative Weiss constant of θ =-15 K , the low-temperature magnetic measurements revealed no long-range magnetic ordering down to 70 mK, and suggested the presence of a spin liquid state with a large residual paramagnetism χ0 of 8.5 ×10-6 emu g-1 at the absolute zero temperature. This was supported by the N 14 NMR measurements down to 0.38 K. Further, the low-temperature heat capacities cp down to 68 mK clearly indicated the presence of cp for the spin liquid state, which can be fitted to the power law of T0.62 in the wide temperature range 0.07-4.5 K.

  8. LABORATORY INVESTIGATION OF RESIDUAL LIQUID ORGANICS FROM SPILLS, LEAKS, AND THE DISPOSAL OF HAZARDOUS WASTES IN GROUNDWATER

    EPA Science Inventory

    Organic liquids that are essentially immiscible with water migrate through the subsurface through the influence of capillary, viscous and buoyancy forces. Four experimental methods were employed. First, quantitative displacement experiments using short soil columns; second, add...

  9. LABORATORY INVESTIGATION OF RESIDUAL LIQUID ORGANICS FROM SPILLS, LEAKS, AND THE DISPOSAL OF HAZARDOUS WASTES IN GROUNDWATER

    EPA Science Inventory

    Organic liquids that are essentially immiscible with water migrate through the subsurface through the influence of capillary, viscous and buoyancy forces. Four experimental methods were employed. First, quantitative displacement experiments using short soil columns; second, add...

  10. Soft liquid phase adsorption for fabrication of organic semiconductor films on wettability patterned surfaces.

    PubMed

    Watanabe, Satoshi; Akiyoshi, Yuri; Matsumoto, Mutsuyoshi

    2014-01-01

    We report a soft liquid-phase adsorption (SLPA) technique for the fabrication of organic semiconductor films on wettability-patterned substrates using toluene/water emulsions. Wettability-patterned substrates were obtained by the UV-ozone treatment of self-assembled monolayers of silane coupling agents on glass plates using a metal mask. Organic semiconductor polymer films were formed selectively on the hydrophobic part of the wettability-patterned substrates. The thickness of the films fabricated by the SLPA technique is significantly larger than that of the films fabricated by dip-coating and spin-coating techniques. The film thickness can be controlled by adjusting the volume ratio of toluene to water, immersion angle, immersion temperature, and immersion time. The SLPA technique allows for the direct production of organic semiconductor films on wettability-patterned substrates with minimized material consumption and reduced number of fabrication steps.

  11. Large-scale self-organization of reconfigurable topological defect networks in nematic liquid crystals

    PubMed Central

    Sasaki, Yuji; Jampani, V.S.R.; Tanaka, Chiharu; Sakurai, Nobutaka; Sakane, Shin; Le, Khoa V.; Araoka, Fumito; Orihara, Hiroshi

    2016-01-01

    Topological defects in nematic liquid crystals are ubiquitous. The defects are important in understanding the fundamental properties of the systems, as well as in practical applications, such as colloidal self-assembly, optical vortex generation and templates for molecular self-assembly. Usually, spatially and temporally stable defects require geometrical frustration imposed by surfaces; otherwise, the system relaxes because of the high cost of the elastic energy. So far, multiple defects are kept in bulk nematic liquid crystals by top-down lithographic techniques. In this work, we stabilize a large number of umbilical defects by doping with an ionic impurity. This method does not require pre-patterned surfaces. We demonstrate that molecular reorientation controlled by an AC voltage induces periodic density modulation of ions accumulated at an electrically insulating polymer interface, resulting in self-organization of a two-dimensional square array of umbilical defects that is reconfigurable and tunable. PMID:27819290

  12. CO2-binding Organic Liquids, an Integrated Acid Gas Capture System

    SciTech Connect

    Heldebrant, David J; Koech, Phillip K; Rainbolt, James E; Zheng, Feng

    2011-04-01

    Amine systems are effective for CO2 capture, but they are still inefficient because the solvent regeneration energy is largely defined by the amount of water in the process. Most amines form heat-stable salts with SO2 and COS resulting in parasitic solvent loss and degradation. Stripping the CO2-rich solvent is energy intensive it requires temperatures above 100 °C due to the high specific heat and heat of vaporization of water. CO2-capture processes could be much more energy efficient in a water free amine process. In addition, if the capture-material is chemically compatible with other acid gases, less solvent would be lost to heat-stable salts and the process economics would be further improved. One such system that can address these concerns is Binding Organic Liquids (BOLs), a class of switchable ionic liquids.

  13. Self-organization processes and topological defects in nanolayers in a nematic liquid crystal

    SciTech Connect

    Chuvyrov, A. N.; Girfanova, F. M. Mal'tsev, I. S.

    2008-05-15

    Atomic force microscopy is used to study the self-organization processes that occur during the formation of topological defects in nanomolecular layers in a nematic liquid crystal with the homeotropic orientation of its molecules with respect to the substrate. In this case, a smectic monolayer with a thickness of one molecule length (about 2.2 nm) forms on the substrate, and a nanomolecular layer of a nematic liquid crystal forms above this monolayer. In such virtually two-dimensional layers, numerous different nanoclusters, namely, hut structures, pyramids, raft structures with symmetry C{sub nm} (where n = 2, 4, 5, 6, 7, ?, {infinity}), cones, and nanopools, form [1]. They have a regular shape close to the geometry of solid crystals. Modulated linear structures and topological point defects appear spontaneously in the nanopools and raft structures.

  14. Aza-crown ether complex cation ionic liquids: preparation and applications in organic reactions.

    PubMed

    Song, Yingying; Cheng, Chen; Jing, Huanwang

    2014-09-26

    Aza-crown ether complex cation ionic liquids (aCECILs) were devised, fabricated, and characterized by using NMR spectroscopy, MS, thermogravimetric differential thermal analysis (TG-DTA), elemental analysis and physical properties. These new and room-temperature ILs were utilized as catalysts in various organic reactions, such as the cycloaddition reaction of CO2 to epoxides, esterification of acetic acid and alcohols, the condensation reaction of aniline and propylene carbonate, and Friedel-Crafts alkylation of indole with aldehydes were investigated carefully. In these reactions, the ionic liquid exhibited cooperative catalytic activity between the anion and cation. In addition, the aza-[18-C-6HK][HSO4]2 was the best acidic catalyst in the reactions of esterification and Friedel-Crafts alkylation under mild reaction conditions.

  15. Large-scale self-organization of reconfigurable topological defect networks in nematic liquid crystals.

    PubMed

    Sasaki, Yuji; Jampani, V S R; Tanaka, Chiharu; Sakurai, Nobutaka; Sakane, Shin; Le, Khoa V; Araoka, Fumito; Orihara, Hiroshi

    2016-11-07

    Topological defects in nematic liquid crystals are ubiquitous. The defects are important in understanding the fundamental properties of the systems, as well as in practical applications, such as colloidal self-assembly, optical vortex generation and templates for molecular self-assembly. Usually, spatially and temporally stable defects require geometrical frustration imposed by surfaces; otherwise, the system relaxes because of the high cost of the elastic energy. So far, multiple defects are kept in bulk nematic liquid crystals by top-down lithographic techniques. In this work, we stabilize a large number of umbilical defects by doping with an ionic impurity. This method does not require pre-patterned surfaces. We demonstrate that molecular reorientation controlled by an AC voltage induces periodic density modulation of ions accumulated at an electrically insulating polymer interface, resulting in self-organization of a two-dimensional square array of umbilical defects that is reconfigurable and tunable.

  16. Anomalous Capacitance Maximum of the Glassy Carbon-Ionic Liquid Interface through Dilution with Organic Solvents.

    PubMed

    Bozym, David J; Uralcan, Betül; Limmer, David T; Pope, Michael A; Szamreta, Nicholas J; Debenedetti, Pablo G; Aksay, Ilhan A

    2015-07-02

    We use electrochemical impedance spectroscopy to measure the effect of diluting a hydrophobic room temperature ionic liquid with miscible organic solvents on the differential capacitance of the glassy carbon-electrolyte interface. We show that the minimum differential capacitance increases with dilution and reaches a maximum value at ionic liquid contents near 5-10 mol% (i.e., ∼1 M). We provide evidence that mixtures with 1,2-dichloroethane, a low-dielectric constant solvent, yield the largest gains in capacitance near the open circuit potential when compared against two traditional solvents, acetonitrile and propylene carbonate. To provide a fundamental basis for these observations, we use a coarse-grained model to relate structural variations at the double layer to the occurrence of the maximum. Our results reveal the potential for the enhancement of double-layer capacitance through dilution.

  17. Effect of cation symmetry on the organization of ionic liquids near a charged mica surface.

    PubMed

    Payal, Rajdeep Singh; Balasubramanian, Sundaram

    2014-07-16

    Atomistic molecular dynamics simulations have been carried out to understand the effect of the symmetry of cations on the microscopic organization of ionic liquids near a charged mica surface. Ionic liquids with a 1,3-alkylimidazolium ([C(n)C(m)im](+)) cation and a bis(trifluoromethylsulfonyl)imide ([NTf2](-)) anion were investigated. Apart from symmetry, the length of the alkyl group attached to the cation is found to crucially determine the ion structure near the solid surface. In the first adsorbed layer, the ring planes of cations with shorter alkyl groups (less than four carbon atoms) are oriented either parallel or perpendicular to the surface. However, cations with longer alkyl tails are exclusively observed to have their ring planes parallel to the mica surface. The alkyl groups too show a similar dependence of their orientation on the tail length. Further, symmetric cations with alkyl groups of intermediate length are more highly structured at the interface than their asymmetric counterparts.

  18. A study on the pulsed laser printing of liquid-phase exfoliated graphene for organic electronics

    NASA Astrophysics Data System (ADS)

    Papazoglou, S.; Raptis, Y. S.; Chatzandroulis, S.; Zergioti, I.

    2014-10-01

    The aim of this work is the pulsed laser printing of liquid-phase exfoliated graphene in the nanosecond regime and the optimization of the printing process on Si/SiO2 and flexible polymer substrates (polyethylene naphthalate) via the laser-induced forward transfer technique (LIFT). The laser printing conditions and the optimum energy fluence window for reproducible deposition have been investigated, while the deposited graphene features have been studied morphologically and structurally by means of optical microscopy, micro-Raman spectroscopy and electrical characterization. LIFT experiments were carried out using the fourth harmonic (266 nm) of a pulsed ns Nd:YAG laser combined with a high-power imaging micromachining system to monitor the printing process throughout the experiments. The irradiation of our graphene solution resulted in the deposition of well-resolved patterns on different surfaces, highlighting LIFT as an alternative technique for the printing and patterning of liquid-phase exfoliated graphene for organic electronics applications.

  19. Large-scale self-organization of reconfigurable topological defect networks in nematic liquid crystals

    NASA Astrophysics Data System (ADS)

    Sasaki, Yuji; Jampani, V. S. R.; Tanaka, Chiharu; Sakurai, Nobutaka; Sakane, Shin; Le, Khoa V.; Araoka, Fumito; Orihara, Hiroshi

    2016-11-01

    Topological defects in nematic liquid crystals are ubiquitous. The defects are important in understanding the fundamental properties of the systems, as well as in practical applications, such as colloidal self-assembly, optical vortex generation and templates for molecular self-assembly. Usually, spatially and temporally stable defects require geometrical frustration imposed by surfaces; otherwise, the system relaxes because of the high cost of the elastic energy. So far, multiple defects are kept in bulk nematic liquid crystals by top-down lithographic techniques. In this work, we stabilize a large number of umbilical defects by doping with an ionic impurity. This method does not require pre-patterned surfaces. We demonstrate that molecular reorientation controlled by an AC voltage induces periodic density modulation of ions accumulated at an electrically insulating polymer interface, resulting in self-organization of a two-dimensional square array of umbilical defects that is reconfigurable and tunable.

  20. Photogeneration and enhanced charge transport in aligned smectic liquid crystalline organic semiconductor

    SciTech Connect

    Paul, Sanjoy; Ellman, Brett; Tripathi, Suvagata; Twieg, Robert J.

    2015-10-07

    Liquid crystalline organic semiconductors are emerging candidates for applications in electronic and photonic devices. One of the most attractive aspects of such materials is the potential, in principle, to easily control and manipulate the molecular alignment of the semiconductor over large length scales. Here, we explore the consequences of alignment in a model smectic liquid crystalline semiconductor, and find that the photogeneration efficiency is a strong function of incident polarization in aligned samples. A straightforward theory shows that such behavior is a general feature of aligned materials, regardless of the details of photophysics. Furthermore, we uncover tentative evidence that the mobility of aligned samples is substantially enhanced. Both of these phenomena are of significant technological importance.

  1. Ionic liquid assisted hydrothermal fabrication of hierarchically organized γ-AlOOH hollow sphere

    SciTech Connect

    Tang, Zhe; Liu, Yunqi; Li, Guangci; Hu, Xiaofu; Liu, Chenguang

    2012-11-15

    Highlights: ► The γ-AlOOH hollow spheres were synthesized via an ionic liquid-assisted hydrothermal treatment. ► Ionic liquid plays an important role in the morphology of the product. ► Ionic liquid can be easily removed from the product and reused in next experiment. ► A “aggregation–solution–recrystallization” formation mechanism may occur in the system. -- Abstract: Hierarchically organized γ-AlOOH hollow spheres with nanoflake-like porous surface texture have been successfully synthesized via an ionic liquid-assisted hydrothermal synthesis method in citric acid monohydrate (CAMs). It was found that ionic liquid [bmim]{sup +}Cl{sup −} played an important role in the morphology of the product due to its strong interactions with reaction particles. The samples were characterized by X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscope (SEM) and Transmission Electron Microscopy (TEM). The results show that the product has narrow particle size distribution (500–900 nm particle diameter range), high specific surface area (240.5 m{sup 2}/g) and large pore volume (0.61 cm{sup 3}/g). The corresponding γ-Al{sub 2}O{sub 3} hollow spheres can be obtained by calcining it at 550 °C for 3 h. The proposed formation mechanism and other influencing factors of the γ-AlOOH hollow sphere material, such as reaction temperature, reaction duration, CAMs and urea, have also been investigated.

  2. New metal-organic nanomaterials synthesized by laser irradiation of organic liquids

    SciTech Connect

    Kuzmin, Stanislav L.; Wesolowski, Michal J.; Duley, Walter W.

    2014-03-31

    A new type of metal-organic composition consisting of clusters of nanoparticles has been synthesised by laser irradiation of metallocene/benzene solutions. The metallocene molecules in this reaction become the source of the metal. Exposure to high-energy femtosecond laser pulses dehydrogenate benzene molecules and initiate the high-temperature high-pressure conditions that results in the synthesis of new materials. Irradiation experiments have been carried out on ferrocene/benzene and on other solutions. With ferrocene the synthesis of a new compound has been confirmed by X-ray powder diffraction as the peaks detected do not correspond to any known substance in the Crystallography Open Database. Theoretical simulation of the periodic structure of this new carbide predicts that it has hexagonal symmetry and a unit cell with a = 3.2A and c =2.8A. The exact structure is still uncertain but may be determined from scanning tunneling microscope (STM) studies.

  3. Self-organization of jets in electrospinning from free liquid surface: A generalized approach

    NASA Astrophysics Data System (ADS)

    Lukas, David; Sarkar, Arindam; Pokorny, Pavel

    2008-04-01

    Electrospinning has enabled creation of excellent materials for a great number of applications. Previously, it was based on less productive capillary spinners. The present study is based on recent efforts to elevate electrospinning technology to an industrial level by simultaneously provoking innumerable polymeric jets from a sufficiently large liquid surface to increase productivity. Particularly, it deals with electrospinning from free surface of conductive liquids and validates a formulated hypothesis that explains self-organization of jets on one-dimensional free liquid surfaces in terms of electrohydrodynamic instability of surface waves. Here, it is shown how the hypothesis, based on a profound analysis of a dispersion law, explains that above a certain critical value of applied electric field intensity/field strength the system starts to be self-organized in mesocopic scale due to the mechanism of the "fastest forming instability." The mechanism plays a key role in selecting a particular wave with a characteristic wavelength whose amplitude boundlessly grows faster than the others. The fastest growing stationary wave, according to the hypothesis, marks the onset of electrospinning from a free liquid surface with its jets originating from the wave crests. Singularity of this approach lies in predicting critical values of the phenomenon, viz., critical field strength and corresponding critical interjet distance. The critical field strength, will, thereafter, be used in defining a unique dimensionless electrospinning number. It will, subsequently, be shown how the critical interjet distance, i.e., the maximal distance between the neighboring jets, simply depends on the capillary length. The capillary length represents a latent characteristic spatial scale of the system. The theory also predicts interjet distance for field strengths above the critical value. The said prediction is universally applicable for all conductive liquids if it is expressed in terms of

  4. Organics Produced by Irradiation of Frozen and Liquid HCN Solutions: Implications for Chemical Evolution Studies

    NASA Astrophysics Data System (ADS)

    Colín-García, M.; Negrón-Mendoza, A.; Ramos-Bernal, S.

    2009-04-01

    Hydrogen cyanide (HCN), an important precursor of organic compounds, is widely present in extraterrestrial environments. HCN is also readily synthesized in prebiotic simulation experiments. To gain insight into the radiation chemistry of one of the most important and highly versatile constituents of cometary ices, we examined the behavior of over-irradiated frozen and liquid HCN solutions under ionizing radiation. The samples were exposed to gamma radiation at a dose range from 0 up to 419 kGy. Ultraviolet spectroscopy and gas chromatography were used to follow the process. The analyses confirmed that gamma-ray irradiation of liquid HCN solutions generates several organic products. Many of them are essential to life; we verified the presence of carboxylic acids (some of them members of the Krebs cycle) as well as free amino acids and urea. These are the first studies to reveal the presence of these compounds in experiments performed at low temperatures and bulk irradiation. Organic material was produced even at low temperatures and low radiation doses. This work strongly supports the presumption that, as a parent molecule, HCN played a central essential role in the process of chemical evolution on early Earth, comets, and other extraterrestrial environments.

  5. Homochiral metal-organic framework used as a stationary phase for high-performance liquid chromatography.

    PubMed

    Kong, Jiao; Zhang, Mei; Duan, Ai-Hong; Zhang, Jun-Hui; Yang, Rui; Yuan, Li-Ming

    2015-02-01

    Metal-organic frameworks are promising porous materials. Chiral metal-organic frameworks have attracted considerable attention in controlling enantioselectivity. In this study, a homochiral metal-organic framework [Co(2) (D-cam)(2) (TMDPy)] (D-cam = D-camphorates, TMDPy = 4,4'-trimethylenedipyridine) with a non-interpenetrating primitive cubic net has been used as a chiral stationary phase in high-performance liquid chromatography. It has allowed the successful separation of six positional isomers and six chiral compounds. The good selectivity and baseline separation, or at least 60% valley separation, confirmed its excellent molecular recognition characteristics. The relative standard deviations for the retention time of run-to-run and column-to-column were less than 1.8 and 3.1%, respectively. These results demonstrate that [Co(2) (D-cam)(2) (TMDPy)] may represent a promising chiral stationary phase for use in high-performance liquid chromatography. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Liquid- and Ice-Phase Kinetics of Singlet Molecular Oxygen with Organic Pollutants

    NASA Astrophysics Data System (ADS)

    Bower, J. P.; Anastasio, C.

    2012-12-01

    Singlet molecular oxygen (1O2*), a reactive state of dissolved oxygen, is formed from a sensitizer chromophore that absorbs light and transfers energy to ground-state O2. The chemistry of 1O2* has been studied predominantly in surface waters and aqueous atmospheric drops, where 1O2* can be an important sink for electron-rich pollutants. In our recent work we have shown that 1O2* concentrations can be enhanced by several orders of magnitude on ice compared to in identical, but unfrozen, aqueous solutions. The goal of this work is to assess the potential importance of 1O2* to the decay of organic pollutants on ice in order to better understand pollutant cycling in the cryosphere. Using 549 nm radiation we illuminated liquid and bulk ice samples containing a 1O2* sensitizer (Rose Bengal), salt (NaCl), and an organic pollutant at a controlled temperature. Organic species were chosen to represent several chemical classes, including furans (furfuryl alcohol), phenols (bisphenol A), and amino acids (tryptophan). During illumination the decay of the pollutant was measured to determine the rate constant for loss by reaction with 1O2*. In all cases we observe enhanced loss of pollutants on ice relative to liquid samples. We will discuss how the magnitude of the ice-phase enhancement depends on the different pollutant classes, their aqueous solubility, and freezing point depression.

  7. Assembling Metal-Organic Frameworks in Ionic Liquids and Supercritical CO2.

    PubMed

    Zhang, Bingxing; Zhang, Jianling; Han, Buxing

    2016-10-06

    Ionic liquids (ILs) and supercritical carbon dioxide (scCO2 ) are both considered to be green solvents with tunable properties. Recently, studies of the synthesis of metal-organic frameworks (MOFs) in the presence of ILs and scCO2 has become a burgeoning direction in chemistry and materials science. ILs have been shown to be ideal media for the synthesis of a variety of MOFs owing to their unique properties including the ability to dissolve a wide range of organic and inorganic compounds and flexible designability. scCO2 has adjustable solvent power and excellent mass-transfer characteristics that offer the opportunity to replace organic solvents for MOF activation, MOF aerogel synthesis, and MOF construction. More interestingly, the simultaneous utilization of IL and scCO2 can combine the advantages of the two liquids, which provides novel routes for the fabrication of MOF structures. This review describes the advances in MOF synthesis in ILs, scCO2 , and IL/scCO2 systems. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Liquid eutectic GaIn as an alternative electrode for PTB7:PCBM organic solar cells

    NASA Astrophysics Data System (ADS)

    Thanh Hau Pham, Viet; Kieu Trinh, Thanh; Tam Nguyen Truong, Nguyen; Park, Chinho

    2017-04-01

    Conventional vacuum deposition process of aluminum (Al) is costly, time-consuming and difficult to apply to the large-scale production of organic photovoltaic devices (OPV). This paper reports a vacuum-free fabrication process of poly[[4,8-bis(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b‧]dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyl]thienophenediyl]:[6,6]-phenyl C71 butyric acid methyl ester (PTB7:PCBM) bulk heterojunction organic solar cell with liquid eutectic gallium-indium (EGaIn) electrode as an alternative to the common Al electrode. The insertion of a thin poly(ethylene oxide) (PEO) layer after depositing organic photoactive layer could help prevent the diffusion of liquid EGaIn into the active layer and allow the deposition of the EGaIn electrode. The PEO interfacial layer was formed by spin-coating from a mixed solvent of alcohol and water. Among different alcohol+water (methanol, ethanol, ethylene glycol, n-propanol, isopropanol, and isobutanol) mixed solvent tested, the n-propanol+water mixed solvent showed the greatest enhancement to the performance of OPVs. The improved device performance was attributed to the reactivity of mixed solvent n-propanol+water toward the surface of PTB7:PCBM active layer, which could help optimize surface morphology.

  9. Molecular dynamics simulation of nanostructural organization in ionic liquid/water mixtures.

    PubMed

    Jiang, Wei; Wang, Yanting; Voth, Gregory A

    2007-05-10

    Molecular dynamics simulations have been carried out to investigate nanostructural organization in mixtures of 1-octyl-3-methylimidazolium nitrate ionic liquid and water at multiple water concentrations. Evolution of the polar network, water network, and micelle structures is visualized and analyzed via partial radial distribution functions. The calculated static partial structure factors show that within the range of water contents examined, polar networks, water networks, and micelles possess an approximately invariant characteristic length at around 20 A. Furthermore, the above calculations point out that, as the amount of water increases, the polar network is continuously broken up (screened) by the intruding water, while the structural organization of the water network and the micelle exhibits a turnover. At the turnover point, the most ordered micelle (cation-cation) structure and water (water-anion-water) network are formed. Thereafter, the structural organization abates drastically, and only loose micelle structure exists due to the dominant water-water interactions. The simulated turnover of structural organization agrees with the sharpest peak in the experimentally obtained structure factor in aqueous solutions of similar ionic liquids; the simulated water structure reveals that water can form liquidlike associated aggregates due to the planar symmetry and strong basicity of NO(3)-, in agreement with experiment. The turnover of structural organization of micelles results from the persistent competition between the hydrophobic interactions of the nonpolar groups and the breakup of the charged polar network with increasing water content, whereas the turnover of the water network results from the competition between the water-water and water-anion interactions.

  10. Dispersive liquid-liquid microextraction based on solidification of floating organic drop and high-performance liquid chromatography to the analysis of cocaine's major adulterants in human urine.

    PubMed

    Sena, Laís Cristina Santana; Matos, Humberto Reis; Dórea, Haroldo Silveira; Pimentel, Maria Fernanda; de Santana, Danielle Cristine Almeida Silva; de Santana, Fernando José Malagueño

    2017-02-01

    A simple method has been proposed for the determination of cocaine's major adulterants (caffeine, levamisole, lidocaine, phenacetin, diltiazem, and hydroxyzine) in human urine by dispersive liquid-liquid microextraction based on solidification of floating organic drop (DLLME-SFO) in combination with high-performance liquid chromatography - photodiode array detector (HPLC-PDA). The reversed-phase chromatographic separation was obtained with a column C18 extended (250×4.6mm; 5μm; 80Å) in gradient elution mode using acetonitrile-trifluoroacetic acid 0.026% (v,v) (pH=2.5) at 1mLmin(-1) as mobile phase, at 25°C, and detection at 235nm. The analysis time was 25min. This condition had the best resolution factors (>1.15), retention factors (>0.68), number of plates (>2094.9), and separation factors (>1.05) for all targets, indicating a good separation. The kind of extraction and dispersive solvent were investigated for unifactorial design. The buffer pH, the volume of extraction and disperser solvent, and the amount of salt were optimized for full factorial design. Under optimum conditions, human urine samples were alkalized with 0.5M sodium phosphate buffer (pH 10) and added to sodium chloride (20%m/v). Acetonitrile (150μL) and 1-dodecanol (30μL) were used as dispersive and extraction solvent, respectively. The method presented linear range of 312.5-3125ngmL(-1) to caffeine and levamisole and 187.5-1875ngmL(-1) to lidocaine, phenacetin, diltiazem, and hydroxyzine. The limit of quantification was 187.5ngmL(-1) to lidocaine, phenacetin, diltiazem, and hydroxyzine and 312.5ngmL(-1) for caffeine and levamisole. The recovery mean values were between 6.0 and 42.6%. The method showed good precision and accuracy, with within- and between-run relative standard deviation and relative error less than 15%. The samples were stable after freeze-thaw cycle and short-term room temperature stability tests. Besides, this method was satisfactorily applied in urine of cocaine users. It

  11. Charge transport in liquid crystalline smectic and discotic organic semiconductors: New results and experimental methodologies

    NASA Astrophysics Data System (ADS)

    Paul, Sanjoy

    Organic electronics offer the possibility of producing low cost, flexible, and large area electronics. Organic semiconductors (OSCs) (organic polymers and crystals), used in organic electronics, are promising materials for novel optical and electronic devices such as organic light emitting diodes, organic field effect transistors, organic sensors, and organic photovoltaics (OPVs). OSCs are composed of molecules weakly held together via van der Walls forces rather than covalent bonds as in the case of inorganic semiconductors such as Si. The combined effect of small wave function overlap, spatial and energetic disorder in organic semiconducting materials lead to localization of charge carriers and, in many cases, hopping conduction. OSCs also differ from conventional semiconductors in that charges photogeneration (e.g., in OPVs) proceeds via the production, diffusion, and dissociation of excitons. Liquid crystalline OSCs (LCOSCs) are semiconductors with phases intermediate between the highly ordered crystalline and completely disordered liquid phases. These materials offer many advantages including facile alignment and the opportunity to study the effects of differing intermolecular geometries on transfer integrals, disorder-induced trapping, charge mobilities, and photogeneration efficiency. In this dissertation work, we explored the photogeneration and charge transport mechanisms in a few model smectic and discotic LCs to better understand the governing principles of photogeneration and charge transport using conventional and novel methods based on the pulsed laser time-of-flight charge carrier transport technique. Four major interrelated topics were considered in this research. First, a sample of smectic LC was aligned in order to compare the resulting hole mobility to that of an unaligned sample, with the aim of understanding how the intermolecular alignment over large length scales affects the hopping probability. The role of the polarization of the

  12. [Determination of organic acids in fermentation broth of spiramycin by high performance liquid chromatography].

    PubMed

    Li, You-yuan; Chen, Chang-hua; Tao, Ping

    2002-01-01

    A method for determining organic acids in spiramycin fermentation broth by high performance liquid chromatography is described. The operating conditions were Zorbax 300-SB C18 column (5 microns, 4.6 mm i.d. x 15 cm) at 35 degrees C, 0.01 mol/L phosphoric acid buffer solution (pH 2.32) and methanol as mobile phase at a flow rate of 0.6 mL/min and UV detection at 210 nm. The relative standard deviations were 0.33%-0.10% and the recoveries were 99.95%-100.08%. It's a simple, rapid and accurate method.

  13. Determination of Steam-Volatile Organic Acids in Fermentation Media by Gas-Liquid Chromatography

    PubMed Central

    Packett, L. V.; McCune, R. W.

    1965-01-01

    Five gas chromatographic liquid phases (25% Carbowax 20 M plus 4% H3PO4, 17.5% dioctyl sebacate plus 7.5% sebacic acid, 17.5% dioctyl sebacate plus 7.5% docosanoic acid, 5% Tween 80, and 20% LAC-296 [poly (diethylene glycol adipate)] plus 2% H3PO4) were studied with respect to their utility in the separation and quantitation of steam-volatile organic acids commonly produced in fermentation. Optimal operating conditions and column stability for routine analysis were established. An Aerograph Hy-Fi gas chromatograph was used for all work, except the studies with Tween 80 in which an Aerograph A-90-C was employed. Chromatographic traces are presented of volatile fatty acid analyses with each of the liquid phases. Complete separation of all isomers of the fatty acids from C2 to C5 was accomplished by the Carbowax 20 M plus H3PO4, dioctyl sebacate plus sebacic acid, and dioctyl sebacate plus docosanoic acid columns. The latter two liquid phases were extremely unstable and proved to be unsatisfactory for analysis of aqueous samples. A column of Carbowax 20 M + H3PO4 separated steam-volatile organic acids completely. The volatile fatty acid isomers were separated by 5% Tween 80 somewhat less completely, and the peak shapes were not as sharp and symmetrical as that desired for good quantitative work. LAC-296 (20%) plus 2% H3PO4 proved to be the most satisfactory of the liquid phases for routine analysis of deproteinated in vitro rumen fermentation media. The column has been used for routine analysis of rumen fermentation fluid and in vitro rumen incubation fluid. All the organic acids from C2 to C5, except isobutyric, could be quantitated with this column. Stability of the column with the aqueous solutions was extremely good. The standard deviation of the analysis of each volatile acid component in a fermentation fluid was less than 0.5 molar per cent. The short-chain organic acids (C2 to C5) were shown to be extremely stable in aqueous solution for as long as 6 months

  14. OPTIMIZED DETERMINATION OF TRACE JET FUEL VOLATILE ORGANIC COMPOUNDS IN HUMAN BLOOD USING IN-FIELD LIQUID-LIQUID EXTRACTION WITH SUBSEQUENT LABORATORY GAS CHROMATOGRAPHIC-MASS SPECTROMETRIC ANALYSIS AND ON-COLUMN LARGE VOLUME INJECTION

    EPA Science Inventory

    A practical and sensitive method to assess volatile organic compounds (VOCs) from JP-8 jet fuel in human whole blood was developed by modifying previously established liquid-liquid extraction procedures, optimizing extraction times, solvent volume, specific sample processing te...

  15. OPTIMIZED DETERMINATION OF TRACE JET FUEL VOLATILE ORGANIC COMPOUNDS IN HUMAN BLOOD USING IN-FIELD LIQUID-LIQUID EXTRACTION WITH SUBSEQUENT LABORATORY GAS CHROMATOGRAPHIC-MASS SPECTROMETRIC ANALYSIS AND ON-COLUMN LARGE VOLUME INJECTION

    EPA Science Inventory

    A practical and sensitive method to assess volatile organic compounds (VOCs) from JP-8 jet fuel in human whole blood was developed by modifying previously established liquid-liquid extraction procedures, optimizing extraction times, solvent volume, specific sample processing te...

  16. One-step synthesis of layered yttrium hydroxides in immiscible liquid-liquid systems: Intercalation of sterically-bulky hydrophobic organic anions and doping of europium ions

    NASA Astrophysics Data System (ADS)

    Watanabe, Mebae; Fujihara, Shinobu

    2014-02-01

    Inorganic-organic layered rare-earth compounds were synthesized on the basis of a biphasic liquid-liquid system in one pot. Layered yttrium hydroxides (LYHs) were chosen as a host material for the intercalation of hydrophobic organic guest anions such as benzoate, sebacate, or laurate. In a typical synthesis, an organic phase dissolving carboxylic acid was placed in contact with an equal amount of an aqueous phase dissolving yttrium nitrate n-hydrate and urea. At elevated temperatures up to 80 °C, urea was hydrolyzed to release hydroxyl anions which were used to form yttrium hydroxide layers. LYHs were then precipitated with the intercalation of carboxylate anions delivered from the organic phase under the distribution law. The structure and the morphology of the LYHs could be modulated by the intercalated anions. Doped with Eu3+ ions, the LYHs exhibited red photoluminescence which was enhanced by the intercalated anions due to the antenna effect.

  17. Feasibility study of the applicability of the activated sludge process to treatment of radioactive organic liquid waste

    SciTech Connect

    Koyama, Akio; Nishimaki, Kenzo

    1997-12-31

    The authors used an activated sludge process to treat radioactive organic liquid waste. Organic liquid waste is difficult to treat by conventional radioactive liquid treatment processes, but in order to reduce long-term irradiation of the public the removal of radionuclides from such waste is preferable to dilution. Activated sludge processes are widely used for the biological treatment of sewage and are considered appropriate means for treating radioactive organic liquid waste. In this process, the fate of radionuclides eluted by treated water or immobilized by activated sludge, is extremely important for public safety and for the treatment of radioactive organic liquid waste. The authors performed uptake and desorption behavior experiments on the three short half-life radionuclides {sup 134}Cs, {sup 57}Co and {sup 85}Sr, and used three nutritive types of artificial sewage as the feed solution. On the basis of the results, they discuss the uptake-desorption behavior of these radionuclides in an activated sludge process. The authors conclude that treatment of radioactive organic liquid waste by an activated sludge process is possible, but improvements must be made in the process if it is to be more effective.

  18. Nanostructural organization and anion effects in the optical Kerr effect spectra of binary ionic liquid mixtures.

    PubMed

    Xiao, Dong; Rajian, Justin Rajesh; Hines, Larry G; Li, Shengfu; Bartsch, Richard A; Quitevis, Edward L

    2008-10-23

    This article reports a study of the effect of anions on the optical Kerr effect (OKE) spectra of binary ionic liquid mixtures with one mixture comprising the 3-methyl-1-pentylimidazolium ([C 5mim] (+)) cation and the anions PF 6 (-) and CF 3CO 2 (-) (TFA (-)), and another mixture comprising the [C 5mim] (+) cation and the anions Br (-) and bis(trifluomethanesulfonyl)imide (NTf 2 (-)). The spectra were obtained by the use of optical heterodyne-detected Raman-induced Kerr Effect Spectroscopy at 295 K. The OKE spectra of the mixtures are compared with the calculated mole-fraction weighted sum of the normalized OKE spectra of the neat liquids. The OKE spectra are nearly additive for [C 5mim]Br/[C 5mim][NTf 2] mixtures, but nonadditive for [C 5mim][PF 6]/[C 5mim][TFA] mixtures. In the case of the equimolar [C 5mim][PF 6]/[C 5mim][TFA] mixture, the nonadditivity is such that the experimental OKE spectrum is narrower than the calculated OKE spectrum. The additivity or nonadditivity of OKE spectra for IL mixtures can be explained by assuming ionic liquids are nanostructurally organized into nonpolar regions and ionic networks. The ionic networks in mixtures will be characterized by "random co-networks" for anions that are nearly the same in size (PF 6 (-) and TFA (-)) and by "block co-networks" for anions that differ greatly in size (Br (-) and NTf 2 (-)).

  19. Panoscopic organization of anisotropic colloidal structures from photofunctional inorganic nanosheet liquid crystals.

    PubMed

    Nakato, Teruyuki; Nono, Yoshihiro; Mouri, Emiko; Nakata, Munetaka

    2014-01-21

    Colloidal liquid crystals of inorganic nanosheets with thickness of around 1 nm and lateral dimensions of several micrometers prepared by exfoliation of a layered niobate are converted to hierarchically organized arrays whose structures are controlled from the nano to macroscopic length scale through the growth of liquid crystalline domains called tactoids as the secondary building blocks followed by controlled application of external fields. Growth of the tactoids is attained by incubation of the liquid crystals at room temperature. The tactoids are then assembled into higher-order structures with characteristic lengths of sub-mm to mm under the simultaneous application of an ac electric field and gravity, whose directions determine the final textural motif of the arrays. Whereas a net-like texture is observed when applying the electric and gravitational forces in the same direction, a striped texture where the nanosheets are unidirectionally aligned is observed when the electric field is applied in the direction perpendicular to gravity. The use of well-grown tactoids is key to the macroscopic structural control. Since the niobate nanosheets have wide band-gap semiconducting nature, the nanosheet stripe arrays exhibit photocatalysis that reflected the alignment of the nanosheets with respect to the polarized direction of impinging light.

  20. Mass transfer from nonaqueous phase organic liquids in water-saturated porous media

    SciTech Connect

    Geller, J.T. ); Hunt, J.R. )

    1993-04-01

    The widespread production and use of industrial solvents and liquid petroleum products have provided ample opportunity for subsurface contamination from leaking underground storage tanks and pipelines, hazardous waste sites, and surface spills. The aqueous solubility of these organic liquid contaminants is low enough for them to exist in the subsurface as nonaqueous phase liquids (NAPLs) but large enough to seriously degrade water quality. In this paper, results from measuring the complete dissolution of trapped NAPLs and developing a model are discussed. The NAPL saturation is modeled as discrete spheres that are initially uniform in size. From the experimental data, ganglia size and the cross-sectional area of the NAPL region are obtained by fitting the model to the data and assuming a fixed initial NAPL saturation. This two-parameter model, when combined with known magnitudes of residual saturation and relative permeability functions represented experimental observations of (1) increasing aqueous concentration during initial water flooding as the mass transfer zone is established, (2) a quasi-steady effluent concentration as the mass transfer zone propagates downstream, and (3) the decline in effluent concentration as the NAPL-containing region shrinks to less than the length of the mass transfer zone. The experimental data and modeling effort illustrate mechanisms that limit the remediation of NAPL-contaminated aquifers. There is a complex dependency of groundwater contaminant concentration on flow velocity.

  1. Liquid chromatographic separation in metal-organic framework MIL-101: a molecular simulation study.

    PubMed

    Hu, Zhongqiao; Chen, Yifei; Jiang, Jianwen

    2013-02-05

    A molecular simulation study is reported to investigate liquid chromatographic separation in metal-organic framework MIL-101. Two mixtures are considered: three amino acids (Arg, Phe, and Trp) in aqueous solution and three xylene isomers (p-, m-, and o-xylene) dissolved in hexane. For the first mixture, the elution order is found to be Arg > Phe > Trp. The hydrophilic Arg has the strongest interaction with the polar mobile phase (water) and the weakest interaction with the stationary phase (MIL-101), and thus transports at the fastest velocity. Furthermore, Arg forms the largest number of hydrogen bonds with water and possesses the largest hydrophilic solvent-accessible surface area. For the second mixture, the elution order is p-xylene > m-xylene > o-xylene, consistent with available experimental observation. With the largest polarity as compared to p- and m-xylenes, o-xylene interacts the most strongly with the stationary phase and exhibits the slowest transport velocity. For both mixtures, the underlying separation mechanism is elucidated from detailed energetic and structural analysis. It is revealed that the separation can be attributed to the cooperative solute-solvent and solute-framework interactions. This simulation study, for the first time, provides molecular insight into liquid chromatographic separation in a MOF and suggests that MIL-101 might be an interesting material for the separation of industrially important liquid mixtures.

  2. Structural and Dielectric Properties of Ionic Liquid Doped Metal Organic Framework based Polymer Electrolyte Nanocomposites

    NASA Astrophysics Data System (ADS)

    Dutta, Rituraj; Kumar, Ashok

    2016-10-01

    Metal Organic Frameworks (MOFs) are mesoporous materials that can be treated as potential hosts for trapping guest molecules in their pores. Ion conduction and phase behavior dynamics of Ionic Liquids (ILs) can be controlled by tunable interactions of MOFs with the ILs. MOFs incorporated with ionic liquid can be dispersed in the polymers to synthesize polymer electrolyte nanocomposites with high ionic conductivity, electrochemical and thermal stability for applications in energy storage and conversion devices such as rechargeable Li-ion batteries. In the present work we have synthesized Cu-based MOF [Cu3(l,3,5-benzene tricarboxylate)2(H2O)] incorporated with the ionic liquid 1-Butyl-3-methylimidazolium bromide at different weight ratios of MOF and IL. The synthesized MOF-IL composites are dispersed in Poly (ethylene oxide) (PEO). Frequency dependent behavior of permittivity and dielectric loss of the nanocomposites depict the non-Debye dielectric relaxation mechanism. The room temperature Nyquist plots reveal decreasing bulk resistance upto 189 Ω with optimum ionic conductivity of 1.3×10-3S cm-1at maximum doping concentration of IL in the nanocomposite system.

  3. Enzymatic synthesis of esculin ester in ionic liquids buffered with organic solvents.

    PubMed

    Hu, Yifan; Guo, Zheng; Lue, Bena-Marie; Xu, Xuebing

    2009-05-13

    The enzymatic esterification of esculin catalyzed by Candida antarctica lipase B (Novozym 435) was carried out in ionic liquid (IL)-organic solvent mixed systems in comparison with individual systems. The reaction behaviors in IL-organic solvents were systemically evaluated using acetone as a model solvent. With organic solvents as media, the esterification rates of esculin depended mainly on its solubility in solvents; for the reactions in ILs, the reaction rates were generally low, and the anion part of the IL played a critical role in enzyme activity. Therefore, the esterification of esculin in IL-acetone mixtures made it possible to improve the solubility of esculin while the effects of ILs on lipase activity were minimized. Following the benignity of ILs to lipase activity, the anions of ILs were ranked in the order as [Tf(2)N](-) > [PF(6)](-) > [BF(4)](-) > [CF(3)SO(3)](-) > [C(4)F(9)SO(3)](-) > [TAF](-) > [MDEGSO(4)](-) > [OctSO(4)](-) > [ES](-) = [DMP](-) = [OTs](- )= Cl(-). The reaction behaviors differed in different systems and largely depended on the properties of the ILs and organic solvents. In general, improvements were observed in terms of both solubility and reaction efficiency. The knowledge acquired in this work gives a better understanding of multiple interactions in IL-organic solvent systems, which provide guidance for system design and optimization.

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

    NASA Technical Reports Server (NTRS)

    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.

  5. Recovery of steroidal glucosiduronic acids from organic solvents containing anionic liquid ion-exchangers

    PubMed Central

    Mattox, Vernon R.; Litwiller, Robert D.; Goodrich, June E.

    1972-01-01

    Solutions of anionic liquid ion-exchangers in organic solvents are potentially useful for extracting steroidal glucosiduronic acids from biological fluids and for purifying mixtures of these acids by chromatography. If a glucosiduronic acid is to be isolated in pure form after either of these procedures, it is necessary to separate it from the ion-exchanger. Separation from an organic solution of tetraheptylammonium chloride may be accomplished by extraction with water under the following conditions, which promote transfer of a glucosiduronate to the aqueous phase: (1) an appropriate solvent (diluent) as the organic phase, (2) the presence in the two-phase mixture of an anion such as myristate or dodecyl sulphate to combine with the tetraheptylammonium ion, and (3) an increase of the pH of the aqueous phase in association with the presence of myristate or dodecyl sulphate. The foregoing factors apply also to removal of glucosiduronates from organic solutions of ion exchangers that are hydrochlorides of tertiary, secondary, or primary amines. Since these amines exert progressively less solubilizing effect for glucosiduronates as the pH of the aqueous phase is increased, the conjugates can be released from the organic phase by adjusting the pH to 10 and omitting the myristate or dodecyl sulphate. PMID:5075265

  6. Surface chemistry of metal-organic frameworks at the liquid-solid interface.

    PubMed

    Zacher, Denise; Schmid, Rochus; Wöll, Christof; Fischer, Roland A

    2011-01-03

    Metal-organic frameworks (MOFs) are a fascinating class of novel inorganic-organic hybrid materials. They are essentially based on classic coordination chemistry and hold much promise for unique applications ranging from gas storage and separation to chemical sensing, catalysis, and drug release. The evolution of the full innovative potential of MOFs, in particular for nanotechnology and device integration, however requires a fundamental understanding of the formation process of MOFs. Also necessary is the ability to control the growth of thin MOF films and the positioning of size- and shape-selected crystals as well as MOF heterostructures on a given surface in a well-defined and oriented fashion. MOFs are solid-state materials typically formed by solvothermal reactions and their crystallization from the liquid phase involves the surface chemistry of their building blocks. This Review brings together various key aspects of the surface chemistry of MOFs.

  7. Liquid-phase exfoliation of expanded graphites into graphene nanoplatelets using amphiphilic organic molecules.

    PubMed

    Park, Ji Sun; Yu, Lan; Lee, Churl Seung; Shin, Kwonwoo; Han, Jong Hun

    2014-03-01

    Graphenes with a two-dimensional lattice of carbons have been widely employed in diverse applications owing to their excellent electrical, thermal, mechanical, and gas-barrier properties. However, the frequently-used reduced graphene oxide (rGO), which is synthesized from natural graphites by strong oxidation and subsequent reduction via highly toxic components, exhibits imperfect characteristics because of remaining defect sites on its basal planes. Therefore, in this work, we present a convenient way to prepare graphene nanoplatelets (GNPs) with minimized defect sites on their basal planes employing liquid-phase exfoliation of edge-functionalized expanded graphites (EGs) with amphiphilic organic molecules. Exfoliated GNPs revealed approximately sub-7-nm-thickness and showed stable dispersibility in an organic media during 9 months. Furthermore, spray-coated GNP films presented homogeneously stacked morphologies without noticeable agglomerations. Copyright © 2013 Elsevier Inc. All rights reserved.

  8. High performance liquid chromatography study of complex oxygenated alkane mixtures from organic aerosols

    NASA Astrophysics Data System (ADS)

    Kalafut-Pettibone, Alicia J.; Klems, Joseph P.; McGivern, W. Sean

    2013-05-01

    The composition of secondary organic aerosol particles is of primary importance both in identifying particle sources and in determining physical parameters, such as cloud condensation nucleus propensity. Further, measurements of composition are valuable in determining the chemistry of formation and aging. In this work, we describe the application of a recently-developed derivatization technique to a complex synthetic organic aerosol derived from the photolysis of 1-iodooctane. The technique utilizes high-performance liquid chromatography (HPLC) coupled to both ultravioletvisible (UV/VIS) spectroscopy and tandem mass spectrometry (MS-MS) to determine the overall distribution of hydroxyl (OH), non-acid carbonyl (C=O), and carboxylic acid (COOH) moieties as well as the specific identities of chromatographically separated products. This composition data will then be used to constrain models of the particle formation mechanisms.

  9. Capillarity in two-phase liquid flow of organic contaminants in ground water

    SciTech Connect

    Demond, A.H.

    1988-01-01

    The objective of this research was to examine the influence of capillary forces on two-phase liquid flow in groundwater. This objective was accomplished by investigating interfacial tension, contact angle, capillary pressure, and relative permeability for systems representative of contaminated aquifers. The interfacial tensions of six compounds, benzaldehyde, bromobenzene, n-dodecane, tetrachloroethylene, 1,1,2-trichloroethane, and o-xylene, were measured using the pendant drop method. The contact angles for these six compounds were measured on five solid surfaces: Teflon, glass, steel, calcite, and albite. Drainage and imbibition capillary pressure relationships were measured for four organic compound-water systems in an unconsolidated sand. Drainage and imbibition relative permeabilities were measured at groundwater velocities for three organic compound-water systems in the same sand.

  10. Alkylimidazolium based ionic liquids: impact of cation symmetry on their nanoscale structural organization.

    PubMed

    Rocha, Marisa A A; Neves, Catarina M S S; Freire, Mara G; Russina, Olga; Triolo, Alessandro; Coutinho, João A P; Santos, Luís M N B F

    2013-09-19

    Aiming at evaluating the impact of the cation symmetry on the nanostructuration of ionic liquids (ILs), in this work, densities and viscosities as a function of temperature and small-wide angle X-ray scattering (SWAXS) patterns at ambient conditions were determined and analyzed for 1-alkyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (asymmetric) and 1,3-dialkylimidazolium bis(trifluoromethylsulfonyl)imide (symmetric) series of ionic liquids. The symmetric IL series, [CN/2CN/2im][NTf2], presents lower viscosities than the asymmetric [CN-1C1im][NTf2] counterparts. For ionic liquids from [C1C1im][NTf2] to [C6C6im][NTf2], an odd-even effect in the viscosity along the cation alkyl side chain length was observed, in contrast with a linear increase found for the ones ranging between [C6C6im][NTf2] and [C10C10im][NTf2]. The analysis of the viscosity data along the alkyl side chain length reveals a trend shift that occurs at [C6C1im][NTf2] for the asymmetric series and at [C6C6im][NTf2] for the symmetric series. These results are further supported by SWAXS measurements at ambient conditions. The gathered data indicate that both asymmetric and symmetric members are characterized by the occurrence of a distinct degree of mesoscopic structural organization above a given threshold in the side alkyl chain length, regardless the cation symmetry. The data also highlight a difference in the alkyl chain dependence of the mesoscopic cluster sizes for symmetric and asymmetric cations, reflecting a different degree of interdigitation of the aliphatic tails in the two families. The trend shift found in this work is related to the structural segregation in the liquid after a critical alkyl length size (CALS) is attained and has particular relevance in the cation structural isomerism with higher symmetry.

  11. Plasma Interaction with Organic Molecules in Liquid as Fundamental Processes in Plasma Medicine.

    PubMed

    Takenaka, Kosuke; Miyazaki, Atsushi; Abe, Hiroya; Uchida, Giichiro; Setsuhara, Yuichi

    2015-03-01

    Investigation of plasma-organic materials interaction in aqueous solution with atmospheric pressure plasmas have been carried out. Degradation of methylene blue (MB) in aqueous solution via atmospheric pressure He plasma exposure through gas/liquid interface have been investigated. The optical emission spectrum shows considerable emissions of He lines and the emission of O, OH and N radicals attributed to dissociation of water (H2O) and air has been confirmed. Structure variation of MB in solution treated with the atmospheric-pressure He plasma has been measured by Fourier transform infrared spectroscopy (FT-IR). The results obtained from FT-IR analysis show degradation of MB in solution treated with the atmospheric-pressure He plasma. The pH effect of MB degradation was investigated using controlled pH solutions by an ultraviolet-visible (UV-Vis) spectroscopy and FT-IR. The results show no effect of MB degradation on pH. The results exhibit that the atmospheric pressure plasmas exposure has made it possible to degrade organic materials in solution due to irradiated radicals from plasma through plasma/liquid interface.

  12. Force Field Benchmark of Organic Liquids. 2. Gibbs Energy of Solvation.

    PubMed

    Zhang, Jin; Tuguldur, Badamkhatan; van der Spoel, David

    2015-06-22

    Quantitative prediction of physical properties of liquids is a longstanding goal of molecular simulation. Here, we evaluate the predictive power of the Generalized Amber Force Field (Wang et al. J. Comput. Chem. 2004, 25, 1157-1174) for the Gibbs energy of solvation of organic molecules in organic solvents using the thermodynamics integration (TI) method. The results are compared to experimental data, to a model based on quantitative structure property relations (QSPR), and to the conductor-like screening models for realistic solvation (COSMO-RS) model. Although the TI calculations yield slightly better correlation to experimental results than the other models, in all fairness we should conclude that the difference between the models is minor since both QSPR and COSMO-RS yield a slightly lower RMSD from that of the experiment (<3.5 kJ/mol). By analyzing which molecules (either as solvents or solutes) are outliers in the TI calculations, we can pinpoint where additional parametrization efforts are needed. For the force field based TI calculations, deviations from the experiment occur in particular when compounds containing nitro or ester groups are solvated into other liquids, suggesting that the interaction between these groups and solvents may be too strong. In the COSMO-RS calculations, outliers mainly occur when compounds containing (in particular aromatic) rings are solvated despite using a ring correction term in the calculations.

  13. Marangoni Convection in Evaporating Organic Liquid Droplets on a Nonwetting Substrate.

    PubMed

    Chandramohan, Aditya; Dash, Susmita; Weibel, Justin A; Chen, Xuemei; Garimella, Suresh V

    2016-05-17

    We quantitatively characterize the flow field inside organic liquid droplets evaporating on a nonwetting substrate. A mushroom-structured surface yields the desired nonwetting behavior with methanol droplets, while use of a cooled substrate (5-15 °C) slows the rate of evaporation to allow quasi-static particle image velocimetry. Visualization reveals a toroidal vortex within the droplet that is characteristic of surface tension-driven flow; we demonstrate by means of a scaling analysis that this recirculating flow is Marangoni convection. The velocities in the droplet are on the order of 10-45 mm/s. Thus, unlike in the case of evaporation on wetting substrates where Marangoni convection can be ignored for the purpose of estimating the evaporation rate, advection due to the surface tension-driven flow plays a dominant role in the heat transfer within an evaporating droplet on a nonwetting substrate because of the large height-to-radius aspect ratio of the droplet. We formulate a reduced-order model that includes advective transport within the droplet for prediction of organic liquid droplet evaporation on a nonwetting substrate and confirm that the predicted temperature differential across the height of the droplet matches experiments.

  14. Surface excess isotherms of organic solvent mixtures in a system made of liquid carbon dioxide and a silicagel surface.

    PubMed

    Vajda, Péter; Guiochon, Georges

    2013-09-20

    The surface excess isotherms of methanol, ethanol, 2-propanol and acetonitrile from liquid carbon dioxide on a silica adsorbent were measured, using the minor disturbance method. The minor disturbance peaks - or system peaks - of each organic modifier were recorded using UV-detection in the whole composition range of the organic/liquid carbon dioxide mixtures, the whole composition range was completed by injecting the modifiers into pure liquid carbon dioxide as well. The excess isotherms were calculated based on the retention of the organic solvent signals. Our results show an enrichment of the organic modifier at the adsorbent surface. The alcohols show multilayer adsorption with an extremely high retention on the silica surface while acetonitrile shows weaker interactions and only a slight trend toward the formation of a multilayer above the surface.

  15. Organic solvents for pharmaceutical parenterals and embolic liquids: a review of toxicity data.

    PubMed

    Mottu, F; Laurent, A; Rufenacht, D A; Doelker, E

    2000-01-01

    Non-aqueous solvents have long been used in subcutaneous or intramuscular pharmaceutical formulations to dissolve water-insoluble drugs. In recent years, the need for these vehicles was increased since the drug discovery process has yielded many poorly water-soluble drugs. Besides, preparations containing embolic materials dissolved in undiluted non-aqueous water-miscible solvents have been proposed for the intravascular treatment of aneurysms, arteriovenous malformations, or tumors. These organic solvents, regarded as chemically and biologically inert, may show pharmacological and toxicological effects. Therefore, knowledge of tolerance and activity of non-aqueous solvents is essential before they can be administered, especially when given undiluted. This paper focuses on thirteen organic solvents reported as possible vehicles for injectable products and details toxicological data when they have been administered intravascularly. These solvents can be subdivided into three groups according to their description in the literature either for intravenous pharmaceutical parenterals or for intravascular embolic liquids: well-documented organic solvents (propylene glycol, polyethylene glycols, ethanol), solvents described in specific applications (dimethyl sulfoxide, N-methyl-2-pyrrolidone, glycofurol, Solketal, glycerol formal, acetone), and solvents not reported in intravascular applications but potentially useful (tetrahydrofurfuryl alcohol, diglyme, dimethyl isosorbide, ethyl lactate). This review of the literature shows that toxicity data on intravascular organic solvents are insufficient because they concern solvents diluted with water and because of the lack of comparative evaluation using the same methodologies.

  16. Organic solvents induce the formation of oil-in-ionic liquid microemulsion aggregations.

    PubMed

    Gao, Yanan; Li, Na; Zhang, Shaohua; Zheng, Liqiang; Li, Xinwei; Dong, Bin; Yu, Li

    2009-02-05

    The role of four organic solvents in the formation process of 1-butyl-3-methylimidazolium tetrafluoroborate (bmimBF4) based ionic liquid (IL) microemulsions is investigated. The results showed that the addition of Triton X-100 remarkably decreased the conductivity of bmimBF4. The added organic solvents provided a strong apolar environment for the hydrophobic tails of Triton X-100 and caused the surfactant molecules to aggregate into the interfacial film of oil-in-bmimBF4 (O/IL) microemulsions. As a result, the conductivities of the solutions were initially increased because the insulative Triton X-100 molecules were assembled, which corresponded to increasing the concentration of continuous bmimBF4 solutions. The hydrophobic interaction between the dispersed organic solvents and the hydrophobic tails of Triton X-100 may be the driving force for the formation of O/IL microemulsions. The droplets of O/IL microemulsions were successively swollen by organic solvents, and a bicontinuous IL-containing microemulsion was observed by freeze-fracture transmission electron microscopy for the first time. The current study can help in further understanding the ILs-containing microemulsions and thereby improve microemulsion theory.

  17. Evaluating analytical ionization quenching correction models for 3D liquid organic scintillator detector

    NASA Astrophysics Data System (ADS)

    Alsanea, F.; Beddar, S.

    2017-05-01

    Proton therapy offers dosimetric advantage over conventional photon therapy due to the finite range of the proton beam, which improves dose conformity. However, one of the main challenges of proton beam therapy is verification of the complex treatment plans delivered to a patient. Thus, 3D measurements are needed to verify the complex dose distribution. A 3D organic scintillator detector is capable of such measurements. However, organic scintillators exhibit a non-linear relation to the ionization density called ionization quenching. The ionization quenching phenomenon in organic scintillators must be accounted for to obtain accurate dose measurements. We investigated the energy deposition by secondary electrons (EDSE) model to explain ionization quenching in 3D liquid organic scintillator when exposed to proton beams. The EDSE model was applied to volumetric scintillation measurement of proton pencil beam with energies of 85.6, 100.9, 144.9 and 161.9 MeV. The quenching parameter in EDSE model ρq was determined by plotting the total light output vs the initial energy of the ion. The results were compared to the Birks semi-empirical formula of scintillation light emission.

  18. A reversible zwitterionic SO2-binding organic liquid

    SciTech Connect

    Heldebrant, David J; Koech, Phillip K; Yonker, Clement R

    2010-01-05

    As fossil fuel consumption continues, there is much attention being focused on capturing acid gas emissions from power plants. We have recently investigated SO2-binding organic liquids (SO2BOLs) as means to reversibly capture and release SO2 selectively over CO2.1 SO2BOLs are mixtures of tertiary amines and alcohols, which bind SO2 as liquid ammonium alkylsulfite salts. Tertiary amines selectively bind SO2 over CO2 because tertiary amines are basic enough to accept a proton from sulfurous and alkylsulfurous acids but not carbonic or alkylcarbonic acids. This is in contrast to other groups who absorb SO2 physically in ionic liquids2-4 or chemically absorb SO2 in organic systems5-7 or as irreversible aqueous bisulfite or sulfite salts.8-11 Our dual component SO2BOL ionic liquids can contain up to 47% SO2 by mass, have low specific heats, and can be desulfoxylated by heating to 90ºC.1 We believed that a bifunctional tertiary alkanol amine would be able to capture SO2 comparable to our binary SO2BOL system. We present here the first reversible zwitterionic liquid produced from the reaction of SO2 with N,N-dibutylundecanolamine (DBUA). The SO2 is chemically bound through the alcohol moiety as an alkylsulfite, which we believe is stabilized by hydrogen bonding through the protonated amine portion of the molecule. Our recent interest in SO2BOLs led us to explore the possible reaction of aprotic alkanolamines with SO2 to form single-component SO2BOLs. A symbiotic pairing of the base and the alcohol on one molecule allows for a simple unimolecular system compared to the binary SO2BOL system. The bifunctional molecule also would have reduced volatility compared to tertiary amines due to increased hydrogen bonding from the alcohol moiety. To our knowledge

  19. Fluorescent and Electroactive Low-Viscosity Tetrazine-Based Organic Liquids.

    PubMed

    Allain, Clémence; Piard, Jonathan; Brosseau, Arnaud; Han, Madeleine; Paquier, Julien; Marchandier, Thomas; Lequeux, Médéric; Boissière, Cédric; Audebert, Pierre

    2016-08-10

    New fluorescent molecular liquids with a tetrazine core have been prepared. These compounds remain liquid at least down to -60 °C and display very low viscosities (28 mPa.s for liquid 1, 58 mPa.s for liquid 2). Both compounds remain fluorescent in the condensed phase. For liquid 1, intermolecular quenching is observed to a certain extent, whereas liquid 2 displays similar photophysical properties in dilute solution and in neat film.

  20. Assessment of dispersive liquid-liquid microextraction conditions for gas chromatography time-of-flight mass spectrometry identification of organic compounds in honey.

    PubMed

    Moniruzzaman, M; Rodríguez, I; Rodríguez-Cabo, T; Cela, R; Sulaiman, S A; Gan, S H

    2014-11-14

    The suitability of the dispersive liquid-liquid microextraction (DLLME) technique for gas chromatography (GC) characterization of minor organic compounds in honey samples is evaluated. Under optimized conditions, samples were pre-treated by liquid-liquid extraction with acetonitrile followed by DLLME using carbon tetrachloride (CCl4, 0.075 mL) as extractant. The yielded settled phase was analyzed by GC using high resolution time-of-flight (TOF) mass spectrometry (MS). The whole sample preparation process is completed in approximately 10 min, with a total consumption of organic solvents below 4 mL, relative standard deviations lower than 12% and with more than 70 organic compounds, displaying linear retention index in the range from 990 to 2900, identified in the obtained extracts. In comparison with HS SPME extraction, higher peak intensities were attained for most volatile and semi-volatile compounds amenable to both extraction techniques. Furthermore, other species such as highly polar and water soluble benzene acids, long chain fatty acids, esters and flavonoids, which are difficult to concentrate by HS SPME, could be identified in DLLME extracts. Some of the compounds identified in DLLME extracts have been proposed as useful for samples classification and/or they are recognized as markers of honeys from certain geographic areas. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Influence of organic solvent on the separation of an ionic liquid from a lignin-ionic liquid mixture.

    PubMed

    Weerachanchai, Piyarat; Lim, Kok Hwa; Lee, Jong-Min

    2014-03-01

    Sixteen solvents added in lignin-ionic liquid mixture provide four types of solubility characteristics. The distinct characteristics can be classified by considering solubility parameters including ET Scale, Kamlet-Taft parameters and solubility parameters. Group 1 solvent shows promising solvents for lignin-ionic liquid separation, contributing full dissolution of ionic liquid with lignin precipitation. Isopropanol, the most potential solvent has solubility properties as following normalized molar electronic transition energies (ET(N))=0.57, hydrogen-bond acidity (α)=0.76 and Hildebrand solubility parameter (δT)=23.58. This study examines potential solvents for ionic recovery, provides simple method of separation and leads to the feasibility of using ionic liquids in industrial applications.

  2. A novel dispersive liquid-liquid microextraction based on solidification of floating organic droplet method for determination of polycyclic aromatic hydrocarbons in aqueous samples.

    PubMed

    Xu, Hui; Ding, Zongqing; Lv, Lili; Song, Dandan; Feng, Yu-Qi

    2009-03-16

    A new dispersive liquid-liquid microextraction based on solidification of floating organic droplet method (DLLME-SFO) was developed for the determination of five kinds of polycyclic aromatic hydrocarbons (PAHs) in environmental water samples. In this method, no specific holder, such as the needle tip of microsyringe and the hollow fiber, is required for supporting the organic microdrop due to the using of organic solvent with low density and proper melting point. Furthermore, the extractant droplet can be collected easily by solidifying it in the lower temperature. 1-Dodecanol was chosen as extraction solvent in this work. A series of parameters that influence extraction were investigated systematically. Under optimal conditions, enrichment factors (EFs) for PAHs were in the range of 88-118. The limit of detections (LODs) for naphthalene, diphenyl, acenaphthene, anthracene and fluoranthene were 0.045, 0.86, 0.071, 1.1 and 0.66ngmL(-1), respectively. Good reproducibility and recovery of the method were also obtained. Compared with the traditional liquid-phase microextraction (LPME) and dispersive liquid-liquid microextraction (DLLME) methods, the proposed method obtained about 2 times higher enrichment factor than those in LPME. Moreover, the solidification of floating organic solvent facilitated the phase transfer. And most importantly, it avoided using high-density and toxic solvent in the traditional DLLME method. The proposed method was successfully applied to determinate PAHs in the environmental water samples. The simple and low-cost method provides an alternative method for the analysis of non-polar compounds in complex environmental water.

  3. Electron spin-lattice relaxation mechanisms of nitroxyl radicals in ionic liquids and conventional organic liquids: temperature dependence of a thermally activated process.

    PubMed

    Kundu, Krishnendu; Kattnig, Daniel R; Mladenova, Boryana Y; Grampp, Günter; Das, Ranjan

    2015-03-26

    -anisotropy, A-anisotropy and spin-rotation interactions from the observed electron spin-lattice relaxation rates, the contribution of the thermally activated process was obtained and compared with its expression for the temperature dependence. Consistent values of various fitted parameters, used in the expression of the thermal process, have been found, and the applicability of the expression of the thermally activated process to describe the temperature dependence in liquid solutions has been vindicated. Moderate solvent dependence of the thermally activated process has also been observed. The rotational correlation times and the spin-lattice relaxation processes of nitroxyls in ionic liquids and in conventional organic liquids are shown to be explicable on a similar footing, requiring no special treatment for ionic liquids.

  4. Critical assessment of liquid density estimation methods for multifunctional organic compounds and their use in atmospheric science.

    PubMed

    Barley, Mark H; Topping, David O; McFiggans, Gordon

    2013-04-25

    In order to model the properties and chemical composition of secondary organic aerosol (SOA), estimated physical property data for many thousands of organic compounds are required. Seven methods for estimating liquid density are assessed against experimental data for a test set of 56 multifunctional organic compounds. The group contribution method of Schroeder coupled with the Rackett equation using critical properties by Nannoolal was found to give the best liquid density values for this test set. During this work some problems with the representation of certain groups (aromatic amines and phenols) within the critical property estimation methods were identified, highlighting the importance (and difficulties) of deriving the parameters of group contribution methods from good quality experimental data. A selection of the estimation methods are applied to the 2742 compounds of an atmospheric chemistry mechanism, which showed that they provided consistent liquid density values for compounds with such atmospherically important (but poorly studied) functional groups as hydroperoxide, peroxide, peroxyacid, and PAN. Estimated liquid density values are also presented for a selection of compounds predicted to be important in atmospheric SOA. Hygroscopic growth factor (a property expected to depend on liquid density) has been calculated for a wide range of particle compositions. A low sensitivity of the growth factor to liquid density was found, and a single density value of 1350 kg·m(-3) could be used for all multicomponent SOA in the calculation of growth factors for comparison with experimentally measured values in the laboratory or the field without incurring significant error.

  5. Single-drop coacervative microextraction of organic compounds prior to liquid chromatography. Theoretical and practical considerations.

    PubMed

    López-Jiménez, Francisco José; Rubio, Soledad; Pérez-Bendito, Dolores

    2008-06-27

    Coacervates made of surfactant aggregates, namely aqueous and reverse micelles and vesicles, were firstly used as solvents in single-drop microextraction (SDME) and proposed for the extraction and concentration of chlorophenols prior to liquid chromatography. The formation of coacervate drops in the needle tip of conventional microsyringes depended on the type of intermolecular forces established between the surfactant headgroups making up the supramolecular aggregates; hydrogen bond interactions were strong enough to permit the formation of spherical drops. Stability of 1-50 microL coacervate drops was achieved by introducing the microsyringe needle tip in a PTFE rod, the end of which had been machined out with a heated flanging-tool to get circular flanges (diameters in the range 3.5-6 mm). The parameters affecting the efficiency of single-drop coacervative microextraction (SDCME) were investigated using vesicular coacervates as a solvent and 2-chlorophenol (CP), 2,4-dichlorophenol (DCP), 2,4,6-trichlorophenol (TCP) and pentachlorophenol (PCP) as model analytes. Coacervative microextraction dynamics fit to the general rate equation of liquid-liquid extraction. The effect of variables such as extraction time, drop volume, stirring rate, pH and temperature, on the extraction of chlorophenols was similar to that described for organic solvent drops. Electrolyte concentrations above 0.1 M caused drop instability. Under the optimum conditions, detection limits were in the range 0.1-0.3 microg L(-1). The relative standard deviation was between 4.3 and 5.6 at 20 microg L(-1) spiked level. The method was applied to the determination of the four chlorophenols in wastewater, superficial water from a reservoir and groundwater and the recoveries were in the range 79 and 106% at 5-20 microg L(-1) spiked level.

  6. Characterization of a ^6Li-loaded organic liquid scintillator for fast neutron spectrometry

    NASA Astrophysics Data System (ADS)

    Bass, C. D.; Heimbach, C. R.; Nico, J. S.; Beise, E. J.; Breuer, H.; Erwin, D.; Langford, T.; Rodrigues, A.

    2010-11-01

    Fast neutrons induced by natural radioactivity and cosmic rays are important sources of background for low-background searches of dark matter, neutrinoless double beta decay, and solar neutrinos. One method for performing fast neutron spectroscopy involves a capture-gated coincidence between a fast neutron that thermalizes through elastic scattering within an organic scintillator and its subsequent capture on a nuclide having a high thermal neutron capture cross section. Thermalization within an organic scintillator occurs within a few ns, but the neutron capture time is typically of order 10s to 100s of μs. A capture signal preceded by a thermalization signal within a characteristic time can be used to select those fast neutrons that have deposited all of their kinetic energy into the scintillator, and the thermalization signal can provide spectroscopic information. We report on a number of measurements performed to characterize the properties of an organic liquid scintillator based on di-isopropyl naphthalene and loaded with ^6Li. This work has been carried out within a joint UMd and NIST project to develop a fast neutron spectrometer suitable for use in a deep underground, low-background laboratory. In particular, we report on measurements of optical properties, light yield, and fast neutron response.

  7. Highly organized smectic-like packing in vapor-deposited glasses of a liquid crystal

    DOE PAGES

    Gujral, Ankit; Gomez, Jaritza; Jiang, Jing; ...

    2016-12-26

    Glasses of a model smectic liquid crystal-forming molecule, itraconazole, were prepared by vapor deposition onto substrates with temperatures ranging from Tsubstrate = 0.78Tg to 1.02Tg, where Tg (=330 K) is the glass transition temperature. The films were characterized using X-ray scattering techniques. For Tsubstrate near and below Tg, glasses with layered smectic-like structures can be prepared and the layer spacing can be tuned by 16% through the choice of Tsubstrate. Remarkably, glasses prepared with Tsubstrate values above Tg exhibit levels of structural organization much higher than that of a thermally annealed film. These results are explained by a mechanism basedmore » upon a preferred molecular orientation and enhanced molecular motion at the free surface, indicating that molecular organization in the glass is independent of the anchoring preferred at the substrate. Furthermore, these results suggest new strategies for optimizing molecular packing within active layers of organic electronic and optoelectronic devices.« less

  8. Highly organized smectic-like packing in vapor-deposited glasses of a liquid crystal

    SciTech Connect

    Gujral, Ankit; Gomez, Jaritza; Jiang, Jing; Huang, Chengbin; O’Hara, Kathryn A.; Toney, Michael F.; Chabinyc, Michael L.; Yu, Lian; Ediger, M. D.

    2016-12-26

    Glasses of a model smectic liquid crystal-forming molecule, itraconazole, were prepared by vapor deposition onto substrates with temperatures ranging from Tsubstrate = 0.78Tg to 1.02Tg, where Tg (=330 K) is the glass transition temperature. The films were characterized using X-ray scattering techniques. For Tsubstrate near and below Tg, glasses with layered smectic-like structures can be prepared and the layer spacing can be tuned by 16% through the choice of Tsubstrate. Remarkably, glasses prepared with Tsubstrate values above Tg exhibit levels of structural organization much higher than that of a thermally annealed film. These results are explained by a mechanism based upon a preferred molecular orientation and enhanced molecular motion at the free surface, indicating that molecular organization in the glass is independent of the anchoring preferred at the substrate. Furthermore, these results suggest new strategies for optimizing molecular packing within active layers of organic electronic and optoelectronic devices.

  9. Viscoelasticity of liquid organic foam: Relaxations, temporal dependence, and bubble loading effects on flow behavior

    NASA Astrophysics Data System (ADS)

    Kropka, Jamie M.; Celina, Mathew

    2010-07-01

    Liquid organic foams are prepared using a new blowing process based on the chemical generation of carbon dioxide. The foams are volumetrically stable for periods up to hours and can be fabricated with gas volume fractions ranging from 0.10 to 0.95. Both the "fresh" and temporal dependences of the linear viscoelastic response of these materials are evaluated. The organic foams exhibit rheological behavior characteristic of their aqueous counterparts: a weak dependence of the shear moduli over an extended frequency/time regime that is bounded by both a fast and slow relaxation. The onset of the fast mechanical response of the organic foams occurs at approximately the same frequency as in aqueous foams despite the continuous phase viscosity differing by orders of magnitude between the systems. This suggests that the viscosity does not affect the time scale of the "anomalous" viscous loss characteristic of these materials, which challenges currently proposed mechanisms for this dissipation and leaves the origin of the loss behavior unclear. The relative contribution of cell growth and bubble motion to the slow relaxation is also discerned by evaluating the relation between the transient and dynamic responses of the foam. Finally, the development of elasticity in the foam due to bubble interactions is analyzed and a bubble slip process is postulated to account for the lack of a true elastic response of the foam at intermediate time scales (between the fast and slow mechanical response) when gas fractions exceed 0.64.

  10. Kinetic studies of the strengthening effect on liquid hot water pretreatments by organic acids.

    PubMed

    Lyu, Huisheng; Lv, Chunliu; Zhang, Minhua; Liu, Jiatao; Meng, Fanmei; Geng, Zhong Feng

    2017-03-22

    The liquid hot water (LHW) pretreatments would be accelerated by the organic acids produced from the process. In the study, the organic acids included not only acetic acid but also lactic acid during LHW hydrolysis of reeds, at 180-220°C and for 15-135min. The lactic acid was presumably produced from xylose degradation in the pretreatment process. The different organic acids, such as acetic acid, lactic acid and acetic-lactic acids, were used to strengthen the LHW pretreatments for increasing xylose production. Moreover, the work presented kinetic models of xylose and hemicellulose at different conditions, considering the generation of lactic acid. The experimental and kinetic results both indicated that acetic-lactic acids had synergistic catalytic effect on the reaction, which could not only inhibit the degradation of xylose, but also promote the hydrolysis of hemicellulose. Besides, the highest concentration of xylose of 7.323g/L was obtained at 200°C, for 45min and with 1wt% acetic-lactic acids.

  11. Evidence for liquid-like and nonideal behavior of a mixture of organic aerosol components

    PubMed Central

    Cappa, Christopher D.; Lovejoy, Edward R.; Ravishankara, A. R.

    2008-01-01

    The condensation, evaporation, and repartitioning of semivolatile organic compounds (SVOCs) in the atmosphere depends both on the phase of condensed material and the effective condensed phase vapor pressures of the SVOCs. Although direct measurements of vapor pressures of individual SVOCs exist, there are limited measurements of how the properties of a given compound changes in mixtures of multiple components that exist in the atmosphere. Here, the evaporation behavior of mixtures of dicarboxylic acids, which are common atmospheric aerosol constituents, is investigated. These measurements demonstrate that complex mixtures of the individually solid organic compounds take on liquid-like properties. Additionally, the vapor pressures of individual components show strong, identity-dependent deviations from ideality (i.e., Raoult's Law), with the vapor pressures of the smaller, more volatile compounds decreased significantly in the mixtures. The addition of an inorganic compound (NaNO3) further influences the nonideal behavior, again in a compound-specific manner. These results suggest that nonideal behavior of particle-phase compounds influences the abundances of organic aerosol observed in the atmosphere and in the laboratory. PMID:19020087

  12. Heteroatom-Containing Porous Carbons Derived from Ionic Liquid-Doped Alkali Organic Salts for Supercapacitors.

    PubMed

    Zhu, Jingyue; Xu, Dan; Qian, Wenjing; Zhang, Jinyu; Yan, Feng

    2016-04-13

    A simple strategy for the synthesis of heteroatom-doped porous carbon materials (CMs) via using ionic liquid (IL)-doped alkali organic salts as small molecular precursors is developed. Doping of alkali organic salts (such as sodium glutamate, sodium tartrate, and sodium citrate) with heteroatoms containing ILs (including 1-butyl-3-methylimidazolium chlorine and 3-butyl-4-methythiazolebromination) not only incorporates the heteroatoms into the carbon frameworks but also highly improves the carbonization yield, as compared with that of either alkali organic salts or ILs as precursors. The porous structure of CMs can be tuned by adjusting the feed ratio of ILs. The porous CMs derived from 1-butyl-3-methylimidazolium chlorine-doped sodium glutamate exhibit high charge storage capacity with a specific capacitance of 287 F g(-1) and good stability over 5000 cycles in 6 m KOH at a current density of 1 A g(-1) for supercapacitors. This strategy opens a simple and efficient method for the synthesis of heteroatom-doped porous CMs.

  13. Numerical studies on self-organized liquid crystal micro photonic systems

    NASA Astrophysics Data System (ADS)

    Matsui, Tatsunosuke; Kitaguchi, Masahiro; Okajima, Akiko

    2014-03-01

    The liquid crystals (LCs) form various types of nano- and micro- structures in a self-organized manner. In recent years, numerous studies have been carried out to develop novel types of optical functional materials and devices utilizing such self-organizing characteristics of the LCs. Based on the finite-difference time-domain (FDTD) method or its extended version, auxiliary differential equation FDTD (ADE-FDTD) method, we have been numerically studying on the optical characteristics and functionalities of the self-organized LCs such as: (1) lasing from the cholesteric LCs (CLCs) and (2) photonic nanojet (PNJ) from LC micro-systems. Based on the ADE-FDTD method incorporating the equation of motion of the macroscopic polarization and the rate equations at the four level energy structures, we have successfully reproduced circularly polarized lasing from CLC at the edge energy of the stop band. It has also been clarified that the introduction of the defect is effective to lower the lasing threshold. Our technique can be utilized to design the CLC laser devise architecture for much lowered lasing threshold. The PNJ from LC micro-systems are uniquely polarized reflecting birefringence of LCs, which cannot be obtained using optically isotropic microdroplets or microcylinders. A small degree of birefringence drastically changes the optical characteristics of the obtained PNJ. Our findings may open the way for the development of the novel optical functional materials and devices.

  14. Towards safer sodium-ion batteries via organic solvent/ionic liquid based hybrid electrolytes

    NASA Astrophysics Data System (ADS)

    Monti, Damien; Ponrouch, Alexandre; Palacín, M. Rosa; Johansson, Patrik

    2016-08-01

    Hybrid electrolytes aimed at application in sodium-ion batteries (SIB) consisting of an organic solvent mixture (EC:PC) and different ionic liquids (ILs); EMImTFSI, BMImTFSI, and Pyr13TFSI, and with the NaTFSI salt providing the Na+ charge carriers have here been extensively studied. The physico-chemical and electrochemical characterisation includes ionic conductivity, viscosity, density, cation coordination and solvation, various safety measures, and electrochemical stability window (ESW). Hybrid electrolytes with 10-50% of IL content were found to have ionic conductivities on par with comparable organic solvent based electrolytes, but with highly enhanced safety properties. A systematic Raman spectroscopy study of the cation coordination and solvation before and after electrolyte safety tests by ignition suggest that IL cations and TFSI remain stable when ignited while organic solvents are consumed. Finally, the solid electrolyte interphase (SEI) formed when using hybrid electrolytes has both better mechanical and electrochemical stability than the SEI derived from pure IL based electrolytes. For a half-cell with a hard carbon (HC) electrode and a hybrid electrolyte with a composition of 0.8 m NaTFSI in EC0.45:PC0.45:Pyr13TFSI0.10 encouraging results were obtained for IL based electrolytes - ca. 182 mAhg-1 at C/10 over 40 cycles.

  15. Hybrid glasses from strong and fragile metal-organic framework liquids

    PubMed Central

    Bennett, Thomas D.; Tan, Jin-Chong; Yue, Yuanzheng; Baxter, Emma; Ducati, Caterina; Terrill, Nick J.; Yeung, Hamish H. -M.; Zhou, Zhongfu; Chen, Wenlin; Henke, Sebastian; Cheetham, Anthony K.; Greaves, G. Neville

    2015-01-01

    Hybrid glasses connect the emerging field of metal-organic frameworks (MOFs) with the glass formation, amorphization and melting processes of these chemically versatile systems. Though inorganic zeolites collapse around the glass transition and melt at higher temperatures, the relationship between amorphization and melting has so far not been investigated. Here we show how heating MOFs of zeolitic topology first results in a low density ‘perfect' glass, similar to those formed in ice, silicon and disaccharides. This order–order transition leads to a super-strong liquid of low fragility that dynamically controls collapse, before a subsequent order–disorder transition, which creates a more fragile high-density liquid. After crystallization to a dense phase, which can be remelted, subsequent quenching results in a bulk glass, virtually identical to the high-density phase. We provide evidence that the wide-ranging melting temperatures of zeolitic MOFs are related to their network topologies and opens up the possibility of ‘melt-casting' MOF glasses. PMID:26314784

  16. Polarization-Sensitive Two-Photon Microscopy Study of the Organization of Liquid-Crystalline DNA

    PubMed Central

    Mojzisova, Halina; Olesiak, Joanna; Zielinski, Marcin; Matczyszyn, Katarzyna; Chauvat, Dominique; Zyss, Joseph

    2009-01-01

    Abstract Highly concentrated DNA solutions exhibit self-ordering properties such as the generation of liquid-crystalline phases. Such organized domains may play an important role in the global chromatin topology but can also be used as a simple model for the study of more complex 3D DNA structures. In this work, using polarized two-photon fluorescence microscopy, we report on the orientation of DNA molecules in liquid-crystalline phases. For this purpose, we analyze the signal emitted by fluorophores that are noncovalently bound to DNA strands. In nonlinear processes, excitation occurs exclusively in the focal volume, which offers advantages such as the reduction of photobleaching of out-of-focus molecules and intrinsic 3D sectioning capability. Propidium iodide and Hoechst, two fluorophores with different DNA binding modes, have been considered. Polarimetric measurements show that the dyes follow the alignment with respect to the DNA strands and allow the determination of the angles between the emission dipoles and the longitudinal axis of the DNA double strand. These results provide a useful starting point toward the application of two-photon polarimetry techniques to determine the local orientation of condensed DNA in physiological conditions. PMID:19843467

  17. Experimental investigations of the entrapment and persistence of organic liquid contaminants in the subsurface environment.

    PubMed Central

    Abriola, L M; Bradford, S A

    1998-01-01

    Organic liquids are common polluters of the subsurface environment. Once released, these nonaqueous phase liquids (NAPLs) tend to become entrapped within soils and geologic formations where they may serve as long-term contaminant reservoirs. The interphase mass transfer from such entrapped residuals will ultimately control environmental exposure levels as well as the persistence and/or remedial recovery of these contaminants in the subsurface. This paper summarizes National Institute of Environmental Health Sciences-sponsored research designed to investigate and quantify NAPL entrapment and interphase mass transfer in natural porous media. Results of soil column and batch experiments are presented that highlight research findings over the past several years. These experiments explore dissolution and volatilization of hydrocarbons and chlorinated solvents in sandy porous media. Initial concentration levels and long-term recovery rates are shown to depend on fluid flow rate, soil structure, NAPL composition, and soil wetting characteristics. These observations are explained in the context of conceptual models that describe entrapped NAPL morphology and boundary layer transport. The implications of these laboratory findings on the subsurface persistence and recovery of entrapped NAPLs are discussed. Images Figure 1 Figure 3 Figure 9 PMID:9703497

  18. Liquid Phase Supercontinuum Fiber-Loop Cavity Enhanced Absorption Spectroscopy for H_{2}O in Organics

    NASA Astrophysics Data System (ADS)

    Li, Mingyun; Lehmann, Kevin

    2017-06-01

    Last year we presented a way of liquid phase sensing for H_{2}O and D_{2}O samples using a side-polished-fiber (SPF) sensor. It is a setup to combine the advantages of Supercontinuum light source with fiber-loop sensing method to make liquid phase CEAS sensing easier and more reliable. After some calculation we found out that with a SPF sensor we could only make use of less than 0.2% of the light from Supercontinuum source, so we decided to make changes on sensors in order to make more light usable. Instead of a SPF or similar evanescent wave sensors, if the light can be guided through a sample directly in free space, we can get almost 100% of the light to be used. So we replaced our sensor by using a mirror and two fibers placed vertical to it side-by-side. The mirror reflects light from one fiber to the other. The free space coupling can make the most of our Supercontinuum source, and a much stronger signal is observed so far. We are now able to use our setup to monitor very low H_{2}O concentrations such as saturated H_{2}O solution in organics like CCl_{4}. Hopefully we can make our system more reliable in the future to make it use in more samples and lower concentrations.

  19. Controlled Growth of Organic Semiconductor Films Using Electrospray Vapor-Liquid-Solid Deposition

    NASA Astrophysics Data System (ADS)

    Shaw, Daniel; Bufkin, Kevin; Johnson, Brad; Patrick, David

    2010-03-01

    Interest in low molecular weight organic semiconductors (OS) for applications such as light-emitting diodes, photovoltaics, and other technologies stems in part from their prospects for enabling significantly reduced manufacturing costs compared to traditional inorganic semiconductors. However many of the best performing prototype devices produced so far have involved expensive or time-consuming fabrication methods, such as the use of single crystals or thin films deposited under high vacuum conditions. New methods are needed capable of rapidly and inexpensively producing high quality polycrystalline films, preferably involving near-ambient conditions. This poster will present studies of one such approach based on an electrospray vapor-liquid-solid growth technique. The method produces polycrystalline OS films deposited via atmospheric-pressure sublimation from a carrier gas (argon) which is partially ionized by a corona discharge. Vapor-phase molecules are then attracted to a charged substrate coated with a thin liquid solvent layer, in which they dissolve and grow as crystals, producing films with large grain sizes. This poster will describe the electrostatic and hydrodynamic features of the deposition mechanism, and the growth kinetics of the resulting polycrystalline films.

  20. Single-reactor process for producing liquid-phase organic compounds from biomass

    DOEpatents

    Dumesic, James A.; Simonetti, Dante A.; Kunkes, Edward L.

    2015-12-08

    Disclosed is a method for preparing liquid fuel and chemical intermediates from biomass-derived oxygenated hydrocarbons. The method includes the steps of reacting in a single reactor an aqueous solution of a biomass-derived, water-soluble oxygenated hydrocarbon reactant, in the presence of a catalyst comprising a metal selected from the group consisting of Cr, Mn, Fe, Co, Ni, Cu, Mo, Tc, Ru, Rh, Pd, Ag, W, Re, Os, Ir, Pt, and Au, at a temperature, and a pressure, and for a time sufficient to yield a self-separating, three-phase product stream comprising a vapor phase, an organic phase containing linear and/or cyclic mono-oxygenated hydrocarbons, and an aqueous phase.

  1. Single-reactor process for producing liquid-phase organic compounds from biomass

    DOEpatents

    Dumesic, James A [Verona, WI; Simonetti, Dante A [Middleton, WI; Kunkes, Edward L [Madison, WI

    2011-12-13

    Disclosed is a method for preparing liquid fuel and chemical intermediates from biomass-derived oxygenated hydrocarbons. The method includes the steps of reacting in a single reactor an aqueous solution of a biomass-derived, water-soluble oxygenated hydrocarbon reactant, in the presence of a catalyst comprising a metal selected from the group consisting of Cr, Mn, Fe, Co, Ni, Cu, Mo, Tc, Ru, Rh, Pd, Ag, W, Re, Os, Ir, Pt, and Au, at a temperature, and a pressure, and for a time sufficient to yield a self-separating, three-phase product stream comprising a vapor phase, an organic phase containing linear and/or cyclic mono-oxygenated hydrocarbons, and an aqueous phase.

  2. Neutron detection in nuclear astrophysics experiments: study of organic liquid scintillators

    NASA Astrophysics Data System (ADS)

    Ciani, Giovanni Francesco

    2016-02-01

    In order to study the nuclear reaction 13 C(α,n)16 O, crucial for the nucleosynthesis of heavy nuclei (A>58), the LUNA collaboration at Laboratori Nazionali del Gran Sasso, is looking for the best neutron detector to use in the set up. One of the possibilities is to use detectors based on cell filled with Organic Liquid Scintillator BC501A. These detectors are sensible to fast neutron, but also to gamma rays. A Pulse Shape Discrimination process using the Zero Crossing method has been performed to select only signals from neutrons. Comparing the neutron spectra after the Pulse Shape Discrimination and the spectrum from a GEANT4 simulations, the efficiency of the BC501A, in function of the neutron energy and varying the light threshold, has been evaluated.

  3. CO2 Binding Organic Liquids Gas Capture with Polarity Swing Assisted Regeneration

    SciTech Connect

    Heldebrant, David

    2014-05-31

    This report outlines the comprehensive bench-scale testing of the CO2-binding organic liquids (CO2BOLs) solvent platform and its unique Polarity Swing Assisted Regeneration (PSAR). This study outlines all efforts on a candidate CO2BOL solvent molecule, including solvent synthesis, material characterization, preliminary toxicology studies, and measurement of all physical, thermodynamic and kinetic data, including bench-scale testing. Equilibrium and kinetic models and analysis were made using Aspen Plus™. Preliminary process configurations, a technoeconomic assessment and solvent performance projections for separating CO2 from a subcritical coal-fired power plant are compared to the U.S. Department of Energy's Case 10 monoethanolamine baseline.

  4. Liquid- and Gas-Phase Diffusion of Ferrocene in Thin Films of Metal-Organic Frameworks

    PubMed Central

    Zhou, Wencai; Wöll, Christof; Heinke, Lars

    2015-01-01

    The mass transfer of the guest molecules in nanoporous host materials, in particular in metal-organic frameworks (MOFs), is among the crucial features of their applications. By using thin surface-mounted MOF films in combination with a quartz crystal microbalance (QCM), the diffusion of ferrocene vapor and of ethanolic and hexanic ferrocene solution in HKUST-1 was investigated. For the first time, liquid- and gas-phase diffusion in MOFs was compared directly in the identical sample. The diffusion coefficients are in the same order of magnitude (~10−16 m2·s−1), whereas the diffusion coefficient of ferrocene in the empty framework is roughly 3-times smaller than in the MOF which is filled with ethanol or n-hexane.

  5. Binary Solvent Organization at Silica/Liquid Interfaces: Preferential Ordering in Acetonitrile-Methanol Mixtures.

    PubMed

    Gobrogge, Eric A; Walker, Robert A

    2014-08-07

    Nonlinear vibrational spectroscopy experiments examined solvent organization at the silica/binary solvent interface where the binary solvent consisted of methanol and acetonitrile in varying mole fractions. Data were compared with surface vibrational spectra acquired from silica surfaces exposed to a vapor phase saturated with the same binary solvent mixtures. Changes in vibrational band intensities suggest that methanol ideally adsorbs to the silica/vapor interface but acetonitrile accumulates in excess relative to vapor-phase composition. At the silica/liquid interface, acetonitrile's signal increases until a solution phase mole fraction of ∼0.85. At higher acetonitrile concentrations, acetonitrile's signal decreases dramatically until only a weak signature persists with the neat solvent. This behavior is ascribed to dipole-paired acetonitrile forming a bilayer with the first sublayer associating with surface silanol groups and a second sublayer consisting of weakly associating, antiparallel partners. On the basis of recent simulations, we propose that the second sublayer accumulates in excess.

  6. Glass-sandwich-type organic solar cells utilizing liquid crystalline phthalocyanine

    NASA Astrophysics Data System (ADS)

    Usui, Toshiki; Nakata, Yuya; De Romeo Banoukepa, Gilles; Fujita, Kento; Nishikawa, Yuki; Shimizu, Yo; Fujii, Akihiko; Ozaki, Masanori

    2017-02-01

    Glass-sandwich-type organic solar cells utilizing liquid crystalline phthalocyanine, 1,4,8,11,15,18,22,25-octahexylphthalocyanine (C6PcH2), have been fabricated and their photovoltaic properties have been studied. The short-circuit current density (J sc) and power conversion efficiency (PCE) depend on the C6PcH2 layer thickness, and the maximum performance, such as a J sc of 7.1 mA/cm2 and a PCE of 1.64%, was demonstrated for a device having a 420-nm-thick C6PcH2 layer. We examined the photovoltaic properties from the viewpoint of the C6PcH2-layer electrical conductance, based on the distribution of the column-axis direction.

  7. Thermodynamics of solvation and association in solutions of fluorosiloxane rubber and polychloroprene in organic liquids

    NASA Astrophysics Data System (ADS)

    Terziyan, T. V.; Safronov, A. P.; Sabirova, A. R.

    2017-07-01

    The enthalpy of dissolution and concentration dependences of the enthalpy of dilution of solutions of fluorosiloxane rubber and polychloroprene in different organic liquids are determined by means of isothermal microcalorimetry. It is established that the processes of polychloroprene dissolution are accompanied by exothermic effects, while those of fluorosiloxane rubber are accompanied by endothermic effects. The calorimetric data are analyzed using the UNIQUAC model to calculate the model parameters associated with the local concentrations of components in the solution that characterize solvation and association. It is shown that the local distribution of the solvent molecules in the polychloroprene solution differed only slightly from the average over the volume, while the process of solvent association predominated in the solution of fluorosiloxane rubber.

  8. Liquid Crystal Phase Transition driven three-dimensional Quantum Dot Organization

    NASA Astrophysics Data System (ADS)

    Rodarte, Andrea L.; Pandolfi, R. J.; Ghosh, S.; Hirst, L. S.

    2013-03-01

    We use a nematic liquid crystal (LC) to create organized assemblies of CdSe/ZnS core/shell quantum dots (QDs). At the isotropic-nematic LC phase transition, ordered domains of nematic LC expel the majority of dispersed QDs into the isotropic domains. The final LC phase produces a series of three dimensional columnar QD assemblies that are situated at defect points in the LC volume. Within each assembly the QD emission is spectrally-red-shifted due to resonant energy transfer. We use this spectral shift as a measure of the inter-dot separation and find that the QDs are packed uniformly in these assemblies over distances of microns between the glass plates of a standard LC cell. In addition, because the QD clusters form at defects, we can deterministically control the location of the assemblies by seeding the LC cell with defect nucleation points. Funding provided by NSF, UC MERI and UC MEXUS.

  9. Methacrylate-bonded covalent-organic framework monolithic columns for high performance liquid chromatography.

    PubMed

    Liu, Li-Hua; Yang, Cheng-Xiong; Yan, Xiu-Ping

    2017-01-06

    Covalent-organic frameworks (COFs) are a newfangled class of intriguing microporous materials. Considering their unique properties, COFs should be promising as packing materials for high performance liquid chromatography (HPLC). However, the irregular shape and sub-micrometer size of COFs synthesized via the traditional methods render the main obstacles for the application of COFs in HPLC. Herein, we report the preparation of methacrylate-bonded COF monolithic columns for HPLC to overcome the above obstacles. The prepared COF bonded monolithic columns not only show good homogeneity and permeability, but also give high column efficiency, good resolution and precision for HPLC separation of small molecules including polycyclic aromatic hydrocarbons, phenols, anilines, nonsteroidal anti-inflammatory drugs and benzothiophenes. Compared with the bare polymer monolithic column, the COF bonded monolithic columns show enhanced hydrophobic, π-π and hydrogen bond interactions in reverse phase HPLC. The results reveal the great potential of COF bonded monoliths for HPLC and COFs in separation sciences.

  10. Liquid Organic Battery Development: Cooperative Research and Development Final Report, CRADA Number CRD-14-540

    SciTech Connect

    Santhanagopalan, Shriram

    2016-08-01

    Battery electric vehicles (BEV) have the potential to significantly reduce consumption of gasoline and emission of greenhouse gases. However, the commercial success of mass-market, long-range BEVs requires battery technology with a challenging combination of technical metrics -- specific energy, safety, fast recharge capability, cycle life, and cost. The NREL team proposes a robust, liquid-phase battery design utilizing a high-energy organic redox couple capable of decoupling these metrics via electrode exchange to provide the necessary combination of performance characteristics. The overall objective of this project is to demonstrate a functioning prototype and determine its ability to meet RANGE performance targets in large-scale production. Three main tasks described below will work towards this goal with the individual objectives of (1) identifying a robust, high-performance redox couple-solvent-additive combination, (2) designing and demonstrating a functional cell, and (3) analyzing the concept's potential performance and cost in future mass-production scenarios.

  11. Comparison of neutron spectra measured with three sizes of organic liquid scintillators using differentiation analysis

    NASA Technical Reports Server (NTRS)

    Shook, D. F.; Pierce, C. R.

    1972-01-01

    Proton recoil distributions were obtained by using organic liquid scintillators of different size. The measured distributions are converted to neutron spectra by differentiation analysis for comparison to the unfolded spectra of the largest scintillator. The approximations involved in the differentiation analysis are indicated to have small effects on the precision of neutron spectra measured with the smaller scintillators but introduce significant error for the largest scintillator. In the case of the smallest cylindrical scintillator, nominally 1.2 by 1.3 cm, the efficiency is shown to be insensitive to multiple scattering and to the angular distribution to the incident flux. These characteristics of the smaller scintillator make possible its use to measure scalar flux spectra within media high efficiency is not required.

  12. Study on Response Function of Organic Liquid Scintillator for High-Energy Neutrons

    NASA Astrophysics Data System (ADS)

    Satoh, Daiki; Sato, Tatsuhiko; Endo, Akira; Yamaguchi, Yasuhiro; Takada, Masashi; Ishibashi, Kenji

    2005-05-01

    Response functions of liquid organic scintillator for neutrons up to 800 MeV have been measured at the Heavy-Ion Medical Accelerator in Chiba (HIMAC) of National Institute of Radiological Sciences (NIRS). 800-MeV/u Si ions and 400-MeV/u C ions bombarded a thick carbon target to produce neutrons. The kinetic energies of emitted neutrons were determined by the time-of-flight (TOF) method. Light output for neutrons was evaluated by eliminating events due to gamma-rays and charged particles. The measured response functions were compared with calculations using SCINFUL-QMD and CECIL codes. It was found that SCINFUL-QMD reproduced our experimental data adequately.

  13. A simple solvent collection technique for a dispersive liquid-liquid microextraction of parabens from aqueous samples using low-density organic solvent.

    PubMed

    Cabuk, Hasan; Akyüz, Mehmet; Ata, Sevket

    2012-10-01

    A simple technique for the collection of an extraction solvent lighter than water after dispersive liquid-liquid microextraction combined with high-performance liquid chromatography with ultraviolet detection was developed for the determination of four paraben preservatives in aqueous samples. After the extraction procedure, low-density organic solvent together with some little aqueous phase was separated by using a disposable glass Pasteur pipette. Next, the flow of the aqueous phase was stopped by successive dipping the capillary tip of the pipette into anhydrous Na(2)SO(4). The upper organic layer was then removed simply with a microsyringe and injected into the high-performance liquid chromatography system. Experimental parameters that affect the extraction efficiency were investigated and optimized. Under optimal extraction conditions, the extraction recoveries ranged from 25 to 86%. Good linearity with coefficients with the square of correlation coefficients ranging from 0.9984 to 0.9998 was observed in the concentration range of 0.001-0.5 μg/mL. The relative standard deviations ranged from 4.1 to 9.3% (n = 5) for all compounds. The limits of detection ranged from 0.021 to 0.046 ng/mL. The method was successfully applied for the determination of parabens in tap water and fruit juice samples and good recoveries (61-108%) were achieved for spiked samples. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Ionic liquid-based totally organic solvent-free emulsification microextraction coupled with high performance liquid chromatography for the determination of three acaricides in fruit juice.

    PubMed

    Zhang, Jiaheng; Liang, Zhe; Guo, Hao; Gao, Peng; Lu, Runhua; Zhou, Wenfeng; Zhang, Sanbing; Gao, Haixiang

    2013-10-15

    A novel, totally organic solvent-free emulsification microextraction (TEME) technique using ionic liquids (ILs) is proposed in this study. Seven bis(trifluoromethylsulfonyl)imide ionic liquids were synthesized. After comparing the physicochemical properties of the ionic liquids and their application to microextraction experiments, 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C6MIM][NTf2]), which has moderate surface tension and viscosity, was selected as the extraction solvent. The dispersion of ILs and mass transfer were accelerated by ultrasound irradiation and temperature control processes. Therefore, no dispersive organic solvent was needed. Several variables, such as ionic liquid volume, duration of the ultrasound extraction, dispersion temperature, ionic strength and centrifugation time were investigated and optimized. Under the optimum conditions, the calibration curve was linear in the range of 0.1-600 μg L(-1) for chlorfenapyr and fenpyroximate and 0.5-600 μg L(-1) for spirodiclofen, with correlation coefficients of 0.9994-0.9999. The enrichment factors were between 261 and 285. The limits of detection (LODs) were 0.02-0.06 μg L(-1). Real fruit juice samples (at fortified levels of 10 μg L(-1) and 30 μg L(-1)) were successfully analyzed using the proposed method. The relative recoveries and enrichment factors were in the range of 92-104%.

  15. Organic solar cells based on liquid crystalline and polycrystalline thin films

    NASA Astrophysics Data System (ADS)

    Yoo, Seunghyup

    This dissertation describes the study of organic thin-film solar cells in pursuit of affordable, renewable, and environmentally-friendly energy sources. Particular emphasis is given to the molecular ordering found in liquid crystalline or polycrystalline films as a way to leverage the efficiencies of these types of cells. Maximum efficiencies estimated based on excitonic character of organic solar cells show power conversion efficiencies larger than 10% are possible in principle. However, their performance is often limited due to small exciton diffusion lengths and poor transport properties which may be attributed to the amorphous nature of most organic semiconductors. Discotic liquid crystal (DLC) copper phthalocyanine was investigated as an easily processible building block for solar cells in which ordered molecular arrangements are enabled by a self-organization in its mesophases. An increase in photocurrent and a reduction in series resistance have been observed in a cell which underwent an annealing process. X-ray diffraction (XRD) and atomic force microscopy (AFM) measurements suggest that structural and morphological changes induced after the annealing process are related to these improvements. In an alternative approach, p-type pentacene thin films prepared by physical vapor deposition were incorporated into heterojunction solar cells with C60 as n-type layers. Power conversion efficiencies of 2.7% under broadband illumination (350--900 nm) with a peak external quantum efficiency of 58% have been achieved with the broad spectral coverage across the visible spectrum. Analysis using an exciton diffusion model shows this efficient carrier generation is mainly due to the large exciton diffusion length of pentacene films. Joint XRD and AFM studies reveal that the highly crystalline nature of pentacene films can account for the observed large exciton diffusion length. In addition, the electrical characteristics are studied as a function of light intensity using

  16. The role of curvature effects in liquid-liquid extraction: assessing organic phase mesoscopic properties from MD simulations.

    PubMed

    Duvail, Magali; van Damme, Steven; Guilbaud, Philippe; Chen, Yushu; Zemb, Thomas; Dufrêche, Jean-François

    2017-08-23

    The bending rigidity of small reverse aggregates involved in liquid-liquid extraction processes has been investigated by molecular dynamics simulations. Simulations of a common extractant (DMDOHEMA) with four hydrophobic chains in explicit solvent (n-heptane) and in vacuum have been performed to determine the effect of solvent penetration on film stiffness. Elastic film bending energy that is needed for mesoscopic modelling of transfer of species between complex fluids is harmonic in terms of curvature (Helfrich formalism) and the packing parameter only if the solvent is explicitly taken into account. In terms of the packing parameter of the real molecular film constituting the reverse water in oil aggregates and taking into account molecular volume, area and film thickness (that is in agreement with Tanford's model), the bending rigidity is calculated to be about 16 kBT per extractant molecule (about 40 kJ mol(-1)), which is smaller than the free energy of transfer from an isolated "monomer" molecule to a weak aggregate, but of the order of magnitude of the free energy of transfer used in liquid-liquid extraction processes.

  17. Observations and implications of liquid-liquid phase separation at high relative humidities in secondary organic material produced by α-pinene ozonolysis without inorganic salts

    NASA Astrophysics Data System (ADS)

    Renbaum-Wolff, Lindsay; Song, Mijung; Marcolli, Claudia; Zhang, Yue; Liu, Pengfei F.; Grayson, James W.; Geiger, Franz M.; Martin, Scot T.; Bertram, Allan K.

    2016-07-01

    Particles consisting of secondary organic material (SOM) are abundant in the atmosphere. To predict the role of these particles in climate, visibility and atmospheric chemistry, information on particle phase state (i.e., single liquid, two liquids and solid) is needed. This paper focuses on the phase state of SOM particles free of inorganic salts produced by the ozonolysis of α-pinene. Phase transitions were investigated in the laboratory using optical microscopy and theoretically using a thermodynamic model at 290 K and for relative humidities ranging from < 0.5 to 100 %. In the laboratory studies, a single phase was observed from 0 to 95 % relative humidity (RH) while two liquid phases were observed above 95 % RH. For increasing RH, the mechanism of liquid-liquid phase separation (LLPS) was spinodal decomposition. The RH range over which two liquid phases were observed did not depend on the direction of RH change. In the modeling studies, the SOM took up very little water and was a single organic-rich phase at low RH values. At high RH, the SOM underwent LLPS to form an organic-rich phase and a water-rich phase, consistent with the laboratory studies. The presence of LLPS at high RH values can have consequences for the cloud condensation nuclei (CCN) activity of SOM particles. In the simulated Köhler curves for SOM particles, two local maxima were observed. Depending on the composition of the SOM, the first or second maximum can determine the critical supersaturation for activation. Recently researchers have observed inconsistencies between measured CCN properties of SOM particles and hygroscopic growth measured below water saturation (i.e., hygroscopic parameters measured below water saturation were inconsistent with hygroscopic parameters measured above water saturation). The work presented here illustrates that such inconsistencies are expected for systems with LLPS when the water uptake at subsaturated conditions represents the hygroscopicity of an organic

  18. Reversed-phase liquid chromatography without organic solvent for determination of tricyclic antidepressants.

    PubMed

    Fernández-Navarro, Juan José; Ruiz-Ángel, María José; García-Álvarez-Coque, María Celia

    2012-06-01

    The chromatographic behavior of seven tricyclic antidepressants (amitryptiline, clomipramine, doxepin, imipramine, maprotiline, nortryptiline, and trimipramine) was examined with micellar mobile phases containing the nonionic surfactant Brij-35. Acetonitrile-water mixtures were also used for comparison purposes. Tricyclic antidepressants are moderately polar basic drugs, which are positively charged in the usual working pH. This gives rise to a strong association with the alkyl chains and residual ionized silanols in silica-based stationary phases, which is translated in a high consumption of organic solvent to get appropriate retention times. Brij-35 modifies the surface of the stationary phases creating a neutral bilayer that masks silanols and reduces the polarity. Consequently, the retention times are decreased. A simple chromatographic procedure for the control of tricyclic antidepressants in pharmaceutical formulations was developed, using 0.02 M Brij-35 at pH 3 and UV detection. Satisfactory recoveries were achieved, with intra- and inter-day relative standard deviations usually below 1 and 2%, respectively. The preparation of the samples was simple and only required solubilization and filtration steps previous to injection. The proposed procedure has the advantage of not using an organic solvent in the mobile phase, and the biodegradable character of Brij-35. This makes an example of "green" liquid chromatographic analysis.

  19. Enantiomeric interactions between liquid crystals and organized monolayers of tyrosine-containing dipeptides.

    PubMed

    Bai, Yiqun; Abbott, Nicholas L

    2012-01-11

    We have examined the orientational ordering of nematic liquid crystals (LCs) supported on organized monolayers of dipeptides with the goal of understanding how peptide-based interfaces encode intermolecular interactions that are amplified into supramolecular ordering. By characterizing the orientations of nematic LCs (4-cyano-4'-pentylbiphenyl and TL205 (a mixture of mesogens containing cyclohexane-fluorinated biphenyls and fluorinated terphenyls)) on monolayers of l-cysteine-l-tyrosine, l-cysteine-l-phenylalanine, or l-cysteine-l-phosphotyrosine formed on crystallographically textured films of gold, we conclude that patterns of hydrogen bonds generated by the organized monolayers of dipeptides are transduced via macroscopic orientational ordering of the LCs. This conclusion is supported by the observation that the ordering exhibited by the achiral LCs is specific to the enantiomers used to form the dipeptide-based monolayers. The dominant role of the -OH group of tyrosine in dictating the patterns of hydrogen bonds that orient the LCs was also evidenced by the effects of phosphorylation of the tyrosine on the ordering of the LCs. Overall, these results reveal that crystallographic texturing of gold films can direct the formation of monolayers of dipeptides with long-range order, thus unmasking the influence of hydrogen bonding, chirality, and phosphorylation on the macroscopic orientational ordering of LCs supported on these surfaces. These results suggest new approaches based on supramolecular assembly for reporting the chemical functionality and stereochemistry of synthetic and biological peptide-based molecules displayed at surfaces.

  20. Rapid simultaneous determination of amines and organic acids in citrus using high-performance liquid chromatography.

    PubMed

    Uckoo, Ram M; Jayaprakasha, Guddadarangavvanahally K; Nelson, Shad D; Patil, Bhimanagouda S

    2011-01-15

    Rapid analytical method for the simultaneous separation and determination of amines and organic acids is a vital interest for quality control of citrus and their products. In the present study, a simultaneous high performance liquid chromatography (HPLC) method for the rapid separation of three amines and two organic acids was developed. Chromatographic separation of compounds was achieved using Xbridge C(18) column at ambient temperature, with an isocratic mobile phase of 3mM phosphoric acid at a flow rate of 1.0 mL min(-1). A photodiode array (PDA) detector was used to monitor the eluent at 223 nm and 254 nm with a total analysis time of 10 min. Extraction of amines and organic acids from citrus juice was optimized. The method was validated by tests of linearity, recovery, precision and ruggedness. The limit of detection (LOD) and limit of quantification (LOQ) for amines and ascorbic acid were determined to be 5 ng and 9.8 ng, respectively. All calibration curves showed good linearity (R(2) ≥ 0.9999) within the test ranges. The recoveries of the amines and organic acids ranged between 84% and 117%. The identity of each peak was confirmed by mass spectral (MS) analysis. The developed method was successfully applied to analyze the content of amines and organic acids in six different species and two varieties of citrus. Results indicate that mandarin and Marrs sweet orange contain high level of amines, while pummelo and Rio Red grapefruit had high content of ascorbic acid (137-251 μg mL(-1)) and citric acid (5-22 mg mL(-1)). Synephrine was the major amine present in Clementine (114 μg mL(-1)) and Marrs sweet orange (85 μg mL(-1)). To the best of our knowledge, this is the first report on simultaneous separation and quantification of amines and organic acids in Marrs sweet orange, Meyer lemon, Nova tangerine, Clementine, Ugli tangelo and Wekiwa tangelo.

  1. [Experimental investigation of possibilities of the ultrasound and liquid-stream dissector in operations on parenchymatous organs].

    PubMed

    Sukhin, I A

    2012-06-01

    The results of experimental investigations were adduced, concerning studying of possibilities and the outcomes analysis of the ultrasound and a liquid-stream dissector application while operating on parenchymatous organs. There was established, that while operating on liver, there was not any essential difference between application of the ultrasound and stream of a liquid concerning the achievement of a quality of the stroma elements isolation; while performing operations on the spleen a liquid-stream dissector have had evolved as a more effective one, permitting to isolate a significantly more quantity of unaffected elements of stroma. The hemostasis methods are the main, which influence the organs stump formation and the typical cellular structure restoration, and they must be applied, using the both methods of dissection.

  2. Titanium-scaffolded organic-monolithic stationary phases for ultra-high-pressure liquid chromatography.

    PubMed

    Vonk, Rudy J; Vaast, Axel; Eeltink, Sebastiaan; Schoenmakers, Peter J

    2014-09-12

    Organic-polymer monoliths with overall dimensions larger than one millimetre are prone to rupture - either within the monolith itself or between the monoliths and the containing wall - due to the inevitable shrinkage accompanying the formation of a cross-linked polymeric network. This problem has been addressed by creating titanium-scaffolded poly(styrene-co-divinylbenzene) (S-co-DVB) monoliths. Titanium-scaffolded monoliths were successfully used in liquid chromatography at very high pressures (up to 80MPa) and using gradients spanning the full range of water-acetonitrile compositions (0 to 100%). The kinetic-performance of (50-mm long) titanium-scaffolded monoliths was compared to that of similar monolith created in 1-mm i.d. glass-lined tubing at pressures up to 50MPa. The peak capacities obtained with the titanium-scaffolded column was about 30% lower. An increased Eddy-diffusion, due to the pillar-structure, and a decreased permeability are thought to be the main reasons for this reduced kinetic-performance. No decrease in performance was observed when the titanium-scaffolded columns were operated at pressures of 80MPa for up to 12h. The column-to-column repeatability (n=5) was acceptable in terms of observed peak widths at half heights (RSD ca. 10%) The run-to-run repeatability (n=135) in terms of retention times and peak widths at half height were found to be good. Titanium-scaffolded columns coupled in series up to a combined length of (200mm) were used for the analyses of a complex Escherichia coli protein sample. Our experiments demonstrate that columns based on titanium-scaffolded organic-polymer monolith can be operated under strenuous conditions without loss in performance. The titanium-scaffolded approach makes it feasible to create organic-polymer monoliths in wide-bore columns with accurate temperature control.

  3. Reactivity of liquid and semisolid secondary organic carbon with chloride and nitrate in atmospheric aerosols

    SciTech Connect

    Wang, Bingbing; O'Brien, Rachel E.; Kelly, Stephen T.; Shilling, John E.; Moffet, Ryan C.; Gilles, Mary K.; Laskin, Alexander

    2015-05-14

    Constituents of secondary organic carbon (SOC) in atmospheric aerosols are often mixed with inorganic components and compose a significant mass fraction of fine particulate matter in the atmosphere. Interactions between SOC and other condensed-phase species are not well understood. Here, we investigate the reactions of liquid-like and semi-solid SOC from ozonolysis of limonene (LSOC) and α-pinene (PSOC) with NaCl using a set of complementary micro-spectroscopic analyses. These reactions result in chloride depletion in the condensed phase, release of gaseous HCl, and formation of organic salts. The reactions attributed to acid displacement by SOC acidic components are driven by the high volatility of HCl. Similar reactions can take place in SOC/NaNO₃ particles. The results show that an increase in SOC mass fraction in the internally mixed SOC/NaCl particles leads to higher chloride depletion. Glass transition temperatures and viscosity of PSOC were estimated for atmospherically relevant conditions. Data show that the reaction extent depends on SOC composition, particle phase state and viscosity, mixing state, temperature, relative humidity (RH), and reaction time. LSOC shows slightly higher potential to deplete chloride than PSOC. Higher particle viscosity at low temperatures and RH can hinder these acid displacement reactions. Formation of organic salts from these overlooked reactions can alter particle physiochemical properties and may affect their reactivity and ability to act as cloud condensation and ice nuclei. The release and potential recycling of HCl and HNO₃ from reacted aerosol particles may have important implications for atmospheric chemistry.

  4. DEMONSTRATION SOLIDIFICATION TESTS CONDUCTED ON RADIOACTIVELY CONTAMINATED ORGANIC LIQUIDS AT THE AECL WHITESHELL LABORATORIES

    SciTech Connect

    Ryz, R. A.; Brunkow, W. G.; Govers, R.; Campbell, D.; Krause, D.

    2002-02-25

    The AECL, Whiteshell Laboratory (WL) near Pinawa Manitoba, Canada, was established in the early 1960's to carry out AECL research and development activities for higher temperature versions of the CANDU{reg_sign} reactor. The initial focus of the research program was the Whiteshell Reactor-1 (WR-1) Organic Cooled Reactor (OCR) that began operation in 1965. The OCR program was discontinued in the early 1970's in favor of the successful heavy-water-cooled CANDU system. WR-1 continued to operate until 1985 in support of AECL nuclear research programs. A consequence of the Federal government's recent program review process was AECL's business decision to discontinue research programs and operations at the Whiteshell Laboratories and to consolidate its' activities at the Chalk River Laboratories. As a result, AECL received government concurrence in 1998 to proceed to plan actions to achieve closure of WL. The planning actions now in progress address the need to safely and effectively transition the WL site from an operational state, in support of AECL's business, to a shutdown and decommissioned state that meets the regulatory requirements for a licensed nuclear site. The decommissioning program that will be required at WL is unique within AECL and Canada since it will need to address the entire research site rather than individual facilities declared redundant. Accordingly, the site nuclear facilities are being systematically placed in a safe shutdown state and planning for the decommissioning work to place the facilities in a secure monitoring and surveillance state is in progress. One aspect of the shutdown activities is to deal with the legacy of radioactively contaminated organic liquid wastes. Use of a polymer powder to solidify these organic wastes was identified as one possibility for improved interim storage of this material pending final disposition.

  5. Ultrasound-air-assisted demulsified liquid-liquid microextraction by solidification of a floating organic droplet for determination of three antifungal drugs in water and biological samples.

    PubMed

    Ezoddin, Maryam; Shojaie, Mehran; Abdi, Khosrou; Karimi, Mohammad Ali

    2017-03-01

    A novel ultrasound-air-assisted demulsified liquid-liquid microextraction by solidification of a floating organic droplet (UAAD-LLM-SFO) followed by HPLC-UV detection was developed for the analysis of three antifungal drugs in water and biological samples. In this method, 1-dodecanol was used as the extraction solvent. The emulsion was rapidly formed by pulling in and pushing out the mixture of sample solution and extraction solvent for 5 times repeatedly using a 10-mL glass syringe while sonication was performed. Therefore, an organic dispersive solvent required in common microextraction methods was not used in the proposed method. After dispersing, an aliquot of acetonitrile was introduced as a demulsifier solvent into the sample solution to separate two phases. Therefore, some additional steps, such as the centrifugation, ultrasonication, or agitation of the sample solution, are not needed. Parameters influencing the extraction recovery were investigated. The proposed method showed a good linearity for the three antifungal drugs studied with the correlation coefficients (R (2) > 0.9995). The limits of detection (LODs) and the limits of the quantification (LOQs) were between 0.01-0.03 μg L(-1) and 0.03-0.08 μg L(-1), respectively. The preconcentration factors (PFs) were in the range of 107-116, respectively. The precisions, as the relative standard deviations (RSDs) (n = 5), for inter-day and intra-day analysis were in the range of 2.1-4.5% and 6.5-8.5%, respectively. This method was successfully applied to determine the three antifungal drugs in tap water and biological samples. The recoveries of antifungal drugs in these samples were 92.4-98.5%. Graphical abstract Ultrasound-air-assisted demulsified liquid-liquid microextraction by solidification of a floating organic droplet for the analysis of three antifungal drugs prior HPLC-UV.

  6. Air-assisted liquid-liquid microextraction by solidifying the floating organic droplets for the rapid determination of seven fungicide residues in juice samples.

    PubMed

    You, Xiangwei; Xing, Zhuokan; Liu, Fengmao; Zhang, Xu

    2015-05-22

    A novel air assisted liquid-liquid microextraction using the solidification of a floating organic droplet method (AALLME-SFO) was developed for the rapid and simple determination of seven fungicide residues in juice samples, using the gas chromatography with electron capture detector (GC-ECD). This method combines the advantages of AALLME and dispersive liquid-liquid microextraction based on the solidification of floating organic droplets (DLLME-SFO) for the first time. In this method, a low-density solvent with a melting point near room temperature was used as the extraction solvent, and the emulsion was rapidly formed by pulling in and pushing out the mixture of aqueous sample solution and extraction solvent for ten times repeatedly using a 10-mL glass syringe. After centrifugation, the extractant droplet could be easily collected from the top of the aqueous samples by solidifying it at a temperature lower than the melting point. Under the optimized conditions, good linearities with the correlation coefficients (γ) higher than 0.9959 were obtained and the limits of detection (LOD) varied between 0.02 and 0.25 μgL(-1). The proposed method was applied to determine the target fungicides in juice samples and acceptable recoveries ranged from 72.6% to 114.0% with the relative standard deviations (RSDs) of 2.3-13.0% were achieved. Compared with the conventional DLLME method, the newly proposed method will neither require a highly toxic chlorinated solvent for extraction nor an organic dispersive solvent in the application process; hence, it is more environmentally friendly.

  7. Dissimilar Crystal Dependence of Vanadium Oxide Cathodes in Organic Carbonate and Safe Ionic Liquid Electrolytes.

    PubMed

    Tartaj, Pedro; Amarilla, Jose M; Morales, Enrique; Vazquez-Santos, Maria B

    2016-01-27

    Advances in Li metal anode stabilization, solid-state electrolytes, and capabilities to insert a variety of active ions (Li(+), Na(+), Mg(2+), and Al(3+)) have renewed the interest in layered vanadium oxides. Here we show that crystal characteristics such as size and crystallinity are fundamental variables that control the dissimilar electrochemical capabilities of 1D vanadium oxides immersed in different electrolytes (organic carbonates and safe electrolytes containing 80% of ionic liquid). We show that this opposite behavior can be understood in terms of a subtle interplay between crystal characteristics (size and crystallinity), electrolyte degradability, and the ionic conductivity of the electrolyte. Thus, through this control we are able to obtain pure 1D vanadium oxides that show reversibility in carbonate electrolytes at a cutoff voltage of 1.5 V (voltage region where insertion of more than two lithium ions is possible). Furthermore, these materials are able to uptake ca. 1.0 mol of Li at a rate of 20C (1C = 295 mAh/g) and retain excellent capabilities (Coulombic efficiency of 98% after 200 cycles at a rate of 5C). Finally, what, to our knowledge, is really remarkable is that this optimization allows building vanadium oxide electrodes with an excellent electrochemical response in a safe electrolyte composition (80% of ionic liquid). Specifically, we reach uptakes also at a cutoff voltage of 1.5 V of ca. 1.0 mol of Li after 200 cycles at 5C (charge/discharge) with Coulombic efficiencies higher than 99.5%.

  8. Use of volatile organic solvents in headspace liquid-phase microextraction by direct cooling of the organic drop using a simple cooling capsule.

    PubMed

    Ghiasvand, Ali Reza; Yazdankhah, Fatemeh; Hajipour, Somayeh

    2016-08-01

    A low-cost and simple cooling-assisted headspace liquid-phase microextraction device for the extraction and determination of 2,6,6-trimethyl-1,3 cyclohexadiene-1-carboxaldehyde (safranal) in Saffron samples, using volatile organic solvents, was fabricated and evaluated. The main part of the cooling-assisted headspace liquid-phase microextraction system was a cooling capsule, with a Teflon microcup to hold the extracting organic solvent, which is able to directly cool down the extraction phase while the sample matrix is simultaneously heated. Different experimental factors such as type of organic extraction solvent, sample temperature, extraction solvent temperature, and extraction time were optimized. The optimal conditions were obtained as: extraction solvent, methanol (10 μL); extraction temperature, 60°C; extraction solvent temperature, 0°C; and extraction time, 20 min. Good linearity of the calibration curve (R(2) = 0.995) was obtained in the concentration range of 0.01-50.0 μg/mL. The limit of detection was 0.001 μg/mL. The relative standard deviation for 1.0 μg/mL of safranal was 10.7% (n = 6). The proposed cooling-assisted headspace liquid-phase microextraction device was coupled (off-line) to high-performance liquid chromatography and used for the determination of safranal in Saffron samples. Reasonable agreement was observed between the results of the cooling-assisted headspace liquid-phase microextraction high-performance liquid chromatography method and those obtained by a validated ultrasound-assisted solvent extraction procedure.

  9. Chemically modified polymeric resins for separation of cations, organic acids, and small polar moleculea by high performance liquid chromatography

    SciTech Connect

    Morris, John B.

    1993-07-01

    This thesis is divided into 4 parts: a review, ion chromatography of metal cations on carboxylic resins, separation of hydrophilic organic acids and small polar compounds on macroporous resin columns, and use of eluent modifiers for liquid chromatographic separation of carboxylic acids using conductivity detection.

  10. Organic liquid thermal conductivity: A prediction method in the reduced temperature range 0.3 to 0.8

    NASA Astrophysics Data System (ADS)

    Baroncini, C.; di Filippo, P.; Latini, G.; Pacetti, M.

    1981-03-01

    A general correlation for organic liquid thermal conductivity, λ, estimation is proposed of the following type: λ = A \\cdot {(1 - T_r)} /{T_r^{{1 6}} }}^{0.38} where T r is the reduced temperature and the factor A is practically temperature independent and characteristic of the particular compound investigated. The values of the factor A for 144 organic liquids are calculated (through selected experimental λ data) and are listed. The proposed correlation is tested, and the mean general deviation between calculated and selected experimental λ values is found to be smaller than 2% over wide temperature ranges (generally from T r = 0.3 to T r =0.8); the maximum deviations are normally smaller than 6%. Successively, the compounds are investigated as members of the respective families in order to provide an expression for A by means of the best available physical properties of the liquids. Correlations are proposed (for alcohols, aromatics, esters, refrigerant fluids, paraffins, cycloparaffins, ketones, organic acids, ethers, and olefins) that contain the same reduced temperature dependence evidenced in the above equation and that differ in the expression suggested for the factor A. In this way, the thermal conductivity of the organic liquids can be evaluated, with a mean deviation generally less than 5%, in absence of experimental λ data.

  11. Dual template effect of supercritical CO2 in ionic liquid to fabricate a highly mesoporous cobalt metal-organic framework.

    PubMed

    Yu, Huanan; Xu, Dongdong; Xu, Qun

    2015-08-28

    A hierarchical meso- and microporous metal-organic framework (MOF) was facilely fabricated in an ionic liquid (IL)/supercritical CO2 (SC CO2)/surfactant emulsion system. Notably, CO2 exerts a dual effect during the synthesis; that is, CO2 droplets act as a template for the cores of nanospheres while CO2-swollen micelles induce mesopores on nanospheres.

  12. Spatiotemporal soil organic carbon dynamics in irrigated corn silage-alfalfa production systems receiving liquid dairy manure

    USDA-ARS?s Scientific Manuscript database

    Accurately measuring soil organic C (SOC) stock changes over time is essential for verifying agronomic management effects on C sequestration. This study quantified the spatial and temporal changes in SOC stocks on adjacent 65-ha corn silage-alfalfa production fields receiving liquid dairy manure in...

  13. Analytical interferences of mercuric chloride preservative in environmental water samples: Determination of organic compounds isolated by continuous liquid-liquid extraction or closed-loop stripping

    USGS Publications Warehouse

    Foreman, W.T.; Zaugg, S.D.; Falres, L.M.; Werner, M.G.; Leiker, T.J.; Rogerson, P.F.

    1992-01-01

    Analytical interferences were observed during the determination of organic compounds in groundwater samples preserved with mercuric chloride. The nature of the interference was different depending on the analytical isolation technique employed. (1) Water samples extracted with dichloromethane by continuous liquid-liquid extraction (CLLE) and analyzed by gas chromatography/mass spectrometry revealed a broad HgCl2 'peak' eluting over a 3-5-min span which interfered with the determination of coeluting organic analytes. Substitution of CLLE for separatory funnel extraction in EPA method 508 also resulted in analytical interferences from the use of HgCl2 preservative. (2) Mercuric chloride was purged, along with organic contaminants, during closed-loop stripping (CLS) of groundwater samples and absorbed onto the activated charcoal trap. Competitive sorption of the HgCl2 by the trap appeared to contribute to the observed poor recoveries for spiked organic contaminants. The HgCl2 was not displaced from the charcoal with the dichloromethane elution solvent and required strong nitric acid to achieve rapid, complete displacement. Similar competitive sorption mechanisms might also occur in other purge and trap methods when this preservative is used.

  14. Determination of descriptors for polycyclic aromatic hydrocarbons and related compounds by chromatographic methods and liquid-liquid partition in totally organic biphasic systems.

    PubMed

    Ariyasena, Thiloka C; Poole, Colin F

    2014-09-26

    Retention factors on several columns and at various temperatures using gas chromatography and from reversed-phase liquid chromatography on a SunFire C18 column with various mobile phase compositions containing acetonitrile, methanol and tetrahydrofuran as strength adjusting solvents are combined with liquid-liquid partition coefficients in totally organic biphasic systems to calculate descriptors for 23 polycyclic aromatic hydrocarbons and eighteen related compounds of environmental interest. The use of a consistent protocol for the above measurements provides descriptors that are more self consistent for the estimation of physicochemical properties (octanol-water, air-octanol, air-water, aqueous solubility, and subcooled liquid vapor pressure). The descriptor in this report tend to have smaller values for the L and E descriptors and random differences in the B and S descriptors compared with literature sources. A simple atom fragment constant model is proposed for the estimation of descriptors from structure for polycyclic aromatic hydrocarbons. The new descriptors show no bias in the prediction of the air-water partition coefficient for polycyclic aromatic hydrocarbons unlike the literature values. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Dissolution of D2EHPA in liquid-liquid extraction process: implication on metal removal and organic content of the treated water.

    PubMed

    Lee, Po-Ching; Li, Chi-Wang; Chen, Jie-Yuan; Li, Ying-Sheng; Chen, Shiao-Shing

    2011-11-15

    Effects of pH, extractant/diluent ratios, and metal concentrations on the extent of extractant dissolution during liquid-liquid extraction were investigated. Experimental result shows that D(2)EHPA dissolution increases dramatically at pH above 4, leveling off at pH 6-7. The phenomenon is consistent with deprotonation of D(2)EHPA and the domination of negatively charged D(2)EHPA species at pH of higher than 4. Concentration of D(2)EHPA in the aqueous phase, i.e., the extent of extractant dissolution, drops after addition of metal and decreases with increasing metal concentration. The amount of D(2)EHPA 're-entering' the organic phase is calculated to be 2.04 mol per mol of Cd added, which is quite closed to the stoichiometric molar ratio of 2 between D(2)EHPA and Cd via ion exchange reaction. The effect of metal species on the extent of extractant/metal complexes re-entering is in the order of Cd ≈ Zn > Ag, which might be coincident to the complexation stability of these metals with D(2)EHPA. The extent of extractant dissolution in liquid-liquid extraction process depends on the type and concentration of metal to be removed, pH of aqueous phase, and extractant/diluent ratios. Copyright © 2011 Elsevier Ltd. All rights reserved.

  16. Liquid Organic Hydrogen Carriers (LOHCs): Toward a Hydrogen-free Hydrogen Economy.

    PubMed

    Preuster, Patrick; Papp, Christian; Wasserscheid, Peter

    2017-01-17

    The need to drastically reduce CO2 emissions will lead to the transformation of our current, carbon-based energy system to a more sustainable, renewable-based one. In this process, hydrogen will gain increasing importance as secondary energy vector. Energy storage requirements on the TWh scale (to bridge extended times of low wind and sun harvest) and global logistics of renewable energy equivalents will create additional driving forces toward a future hydrogen economy. However, the nature of hydrogen requires dedicated infrastructures, and this has prevented so far the introduction of elemental hydrogen into the energy sector to a large extent. Recent scientific and technological progress in handling hydrogen in chemically bound form as liquid organic hydrogen carrier (LOHC) supports the technological vision that a future hydrogen economy may work without handling large amounts of elemental hydrogen. LOHC systems are composed of pairs of hydrogen-lean and hydrogen-rich organic compounds that store hydrogen by repeated catalytic hydrogenation and dehydrogenation cycles. While hydrogen handling in the form of LOHCs allows for using the existing infrastructure for fuels, it also builds on the existing public confidence in dealing with liquid energy carriers. In contrast to hydrogen storage by hydrogenation of gases, such as CO2 or N2, hydrogen release from LOHC systems produces pure hydrogen after condensation of the high-boiling carrier compounds. This Account highlights the current state-of-the-art in hydrogen storage using LOHC systems. It first introduces fundamental aspects of a future hydrogen economy and derives therefrom requirements for suitable LOHC compounds. Molecular structures that have been successfully applied in the literature are presented, and their property profiles are discussed. Fundamental and applied aspects of the involved hydrogenation and dehydrogenation catalysis are discussed, characteristic differences for the catalytic conversion of

  17. Dispersive liquid-liquid microextraction based on solidification of floating organic droplet for the determination of triazine and triazoles in mineral water samples.

    PubMed

    Bolzan, Cátia M; Caldas, Sergiane S; Guimarães, Bruno S; Primel, Ednei G

    2016-09-01

    A simple, rapid, and sensitive method for the determination of atrazine, simazine, cyproconazole, tebuconazole, and epoxiconazole in mineral water employing the dispersive liquid-liquid microextraction with solidification of a floating organic drop with determination by liquid chromatography tandem mass spectrometry has been developed. A mixed solution of 250 μL 1-dodecanol and 1250 μL methanol was injected rapidly into 10 mL aqueous solution (pH 7.0) with 2% w/v NaCl. After centrifugation for 5 min at 2000 rpm, the organic solvent droplets floated on the surface of the aqueous solution and the floating solvent solidified. The method limits of detection were between 3.75 and 37.5 ng/L and limits of quantification were between 12.5 and 125 ng/L. The recoveries ranged from 70 to 118% for repeatability and between 76 and 95% for intermediate precision with a relative standard deviation from 2 to 18% for all compounds. Low matrix effect was observed. The proposed method can be successfully applied in routine analysis for determination of pesticide residues in mineral water samples, allowing for monitoring of triazine and triazoles at levels below the regulatory limits set by international and national legislations. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Fermentation of liquid coproducts and liquid compound diets: Part 2. Effects on pH, acid-binding capacity, organic acids and ethanol during a 6-day storage period.

    PubMed

    Scholten, R H; Rijnen, M M; Schrama, J W; Boer, H; van der Peet-Schwering, C M; Den Hartog, L A; Vesseur, P C; Verstegen, M W

    2001-06-01

    The effects of a 6-day storage period on changes in pH, acid-binding capacity, level of organic acids and ethanol of three liquid coproducts [liquid wheat starch (LWS), mashed potato steam peel (PSP) and cheese whey (CW)] and two liquid compound diets [liquid grower diet (LGD) and liquid finisher diet (LFD)] were studied. All products, except LWS, showed a significant decrease in pH and acid-binding capacity during storage. At the end of the storage period, all products reached a pH of between 3.5 and 3.9. In general, it can be concluded that the lactic acid content, and to a lesser extent the acetic acid content, increased dramatically during storage. In contrast, the ethanol content increased significantly in the liquid compound diets only. The pattern of changes in pH and organic acids during the 6-day storage period was different between the liquid coproducts and the liquid compound diets. At the start of storage, liquid coproducts are already in the 'middle' of the fermentation process, while liquid compound diets need approximately 24-36 h before fermentation begins. Consequently, in practice a different approach to obtain fermented diets is needed for liquid coproducts and liquid compound diets.

  19. Prevalence of approximate square root(t) relaxation for the dielectric alpha process in viscous organic liquids.

    PubMed

    Nielsen, Albena I; Christensen, Tage; Jakobsen, Bo; Niss, Kristine; Olsen, Niels Boye; Richert, Ranko; Dyre, Jeppe C

    2009-04-21

    This paper presents dielectric relaxation data for organic glass-forming liquids compiled from different groups and supplemented by new measurements. The main quantity of interest is the "minimum slope" of the alpha dielectric loss plotted as a function of frequency in a log-log plot, i.e., the numerically largest slope above the loss peak frequency. The data consisting of 347 spectra for 53 liquids show prevalence of minimum slopes close to -1/2, corresponding to approximate square root(t) dependence of the dielectric relaxation function at short times. The paper studies possible correlations between minimum slopes and (1) temperature (quantified via the loss peak frequency); (2) how well an inverse power-law fits data above the loss peak; (3) degree of time-temperature superposition; (4) loss peak half width; (5) deviation from non-Arrhenius behavior; (6) loss strength. For the first three points we find correlations that show a special status of liquids with minimum slopes close to -1/2. For the last three points only fairly insignificant correlations are found, with the exception of large-loss liquids that have minimum slopes that are numerically significantly larger than 1/2. We conclude that--excluding large-loss liquids--approximate square root(t) relaxation appears to be a generic property of the alpha relaxation of organic glass formers.

  20. Comprehensive two-dimensional liquid chromatography: ion chromatography × reversed-phase liquid chromatography for separation of low-molar-mass organic acids.

    PubMed

    Brudin, Stella S; Shellie, Robert A; Haddad, Paul R; Schoenmakers, Peter J

    2010-10-22

    In the work presented here a novel approach to comprehensive two-dimensional liquid chromatography is evaluated. Ion chromatography is chosen for the first-dimension separation and reversed-phase liquid chromatography is chosen for the second-dimension separation mode. The coupling of these modes is made possible by neutralising the first-dimension effluent, containing KOH, prior to transfer to the second-dimension reversed-phase column. A test mixture of 24 low-molar-mass organic acids is used for optimisation of the system. Three food and beverage samples were analysed in order to evaluate the developed methodology, the resulting two-dimensional separation is near-orthogonal, the set-up is simple and all instrumental components are available commercially. The method proved to be robust and suitable for the analysis of wine, orange juice and yogurt.

  1. Dispersive liquid-liquid microextraction based on the solidification of floating organic drop followed by ICP-MS for the simultaneous determination of heavy metals in wastewaters

    NASA Astrophysics Data System (ADS)

    Li, Yong; Peng, Guilong; He, Qiang; Zhu, Hui; Al-Hamadani, Sulala M. Z. F.

    2015-04-01

    In the present work, a dispersive liquid-liquid microextraction based on the solidification of floating organic drop (DLLME-SFO) combined with inductively coupled plasma mass spectrometry (ICP-MS) was developed for the determination of Pb, Co, Cu, Ni, Zn. The influences of analytical parameters, including pH, extraction solvent volume, disperser solvent volume, concentration of chelating agent on the quantitative recoveries of Pb, Co, Cu, Ni, Zn were investigated. The effect of the interfering ions on the analytes recovery was also investigated. Under the optimized conditions, the limits of detection were 0.97-2.18 ng L-1. The relative standard deviations (RSDs) were 2.62-4.51% (n = 7, C = 20 ng L-1). The proposed method was successfully applied for the analysis of ultra trace metals in wastewater samples.

  2. Dispersive liquid-liquid microextraction based on the solidification of floating organic drop followed by ICP-MS for the simultaneous determination of heavy metals in wastewaters.

    PubMed

    Li, Yong; Peng, Guilong; He, Qiang; Zhu, Hui; Al-Hamadani, Sulala M Z F

    2015-04-05

    In the present work, a dispersive liquid-liquid microextraction based on the solidification of floating organic drop (DLLME-SFO) combined with inductively coupled plasma mass spectrometry (ICP-MS) was developed for the determination of Pb, Co, Cu, Ni, Zn. The influences of analytical parameters, including pH, extraction solvent volume, disperser solvent volume, concentration of chelating agent on the quantitative recoveries of Pb, Co, Cu, Ni, Zn were investigated. The effect of the interfering ions on the analytes recovery was also investigated. Under the optimized conditions, the limits of detection were 0.97-2.18 ng L(-1). The relative standard deviations (RSDs) were 2.62-4.51% (n=7, C=20 ng L(-1)). The proposed method was successfully applied for the analysis of ultra trace metals in wastewater samples. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Organic transistors making use of room temperature ionic liquids as gating medium

    NASA Astrophysics Data System (ADS)

    Hoyos, Jonathan Javier Sayago

    The ability to couple ionic and electronic transport in organic transistors, based on pi conjugated organic materials for the transistor channel, can be particularly interesting to achieve low voltage transistor operation, i.e. below 1 V. The operation voltage in typical organic transistors based on conventional dielectrics (200 nm thick SiO2) is commonly higher than 10 V. Electrolyte-gated (EG) transistors, i.e. employing an electrolyte as the gating medium, permit current modulations of several orders of magnitude at relatively low gate voltages thanks to the exceptionally high capacitance at the electrolyte/transistor channel interface, in turn due to the low thickness (ca. 3 nm) of the electrical double layers forming at the electrolyte/semiconductor interface. Electrolytes based on room temperature ionic liquids (RTILs) are promising in EG transistor applications for their high electrochemical stability and good ionic conductivity. The main motivation behind this work is to achieve low voltage operation in organic transistors by making use of RTILs as gating medium. First we demonstrate the importance of the gate electrode material in the EG transistor performance. The use of high surface area carbon gate electrodes limits undesirable electrochemical processes and renders unnecessary the presence of a reference electrode to monitor the channel potential. This was demonstrated using activated carbon as gate electrode, the electronic conducting polymer MEH-PPV, poly[2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylene vinylene] channel material, and the ionic liquid [EMIM][TFSI] (1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide), as gating medium. Using high surface area gate electrodes resulted in sub-1 V operation and charge carrier mobilities of (1.0 +/- 0.5) x 10-2 cm2V -1s-1. A challenge in the field of EG transistors is to decrease their response time, a consequence of the slow ion redistribution in the transistor channel upon application of electric

  4. Planar-orientation polycrystalline thin film of liquid-crystalline organic semiconductor by template-directed self-assembly

    NASA Astrophysics Data System (ADS)

    Wang, Yi-Fei; Iino, Hiroaki; Hanna, Jun-ichi

    2017-10-01

    We fabricated planar-orientation crystalline thin films of organic semiconductors, in which molecules sit parallel, i.e., “face-on”, on the substrate and favor vertical charge transport. Thanks to molecular orientation that is sensitive to surface properties and the self-organization of liquid crystals, planar-orientation crystalline thin films can be prepared by simply cooling a smectic liquid-crystalline organic semiconductor from isotropic temperature with the aid of a poly(vinyl alcohol) (PVA) microtemplate. The molecular orientation of crystalline thin films was investigated by polarized optical microscopy (POM) and X-ray diffraction (XRD) analysis, and the current–voltage characteristics of the films were studied in a diode configuration. The results showed high potential for device applications.

  5. Organized Assemblies of Colloids Formed at the Poles of Micrometer-Sized Droplets of Liquid Crystal

    PubMed Central

    Wang, Xiaoguang; Miller, Daniel S.; de Pablo, Juan J.

    2014-01-01

    We report on the formation of organized assemblies of 1 μm-in-diameter colloids (polystyrene (PS)) at the poles of water-dispersed droplets (diameters 7 - 20 μm) of nematic liquid crystal (LC). For 4-cyano-4′-pentylbiphenyl droplets decorated with two to five PS colloids, we found 32 distinct arrangements of the colloids to form at the boojums of bipolar droplet configurations. Significantly, all but one of these configurations (a ring comprised of five PS colloids) could be mapped onto a local (non-close packed) hexagonal lattice. To provide insight into the origin of the hexagonal lattice, we investigated planar aqueous—LC interfaces, and found that organized assemblies of PS colloids did not form at these interfaces. Experiments involving the addition of salts revealed that a repulsive interaction of electrostatic origin prevented formation of assemblies at planar interfaces, and that regions of high splay near the poles of the LC droplets generated cohesive interactions between colloids that could overcome the repulsion. Support for this interpretation was obtained from a model that included (i) a long-range attraction between adsorbed colloids and the boojum due to the increasing rate of strain (splay) of LC near the boojum (splay attraction), (ii) an attractive inter-colloid interaction that reflects the quadrupolar symmetry of the strain in the LC around the colloids, and (iii) electrostatic repulsion between colloids. The model predicts that electrostatic repulsion between colloids can lead to a ∼1,000 kBT energy barrier at planar interfaces of LC films, and that the repulsive interaction can be overcome by splay attraction of the colloids to the boojums of the LC droplets. Overall, the results reported in this paper advance our understanding of the directed assembly of colloids at interfaces of LC droplets. PMID:25284139

  6. Organized assemblies of colloids formed at the poles of micrometer-sized droplets of liquid crystal.

    PubMed

    Wang, Xiaoguang; Miller, Daniel S; de Pablo, Juan J; Abbott, Nicholas L

    2014-11-28

    We report on the formation of organized assemblies of 1 μm-in-diameter colloids (polystyrene (PS)) at the poles of water-dispersed droplets (diameters 7-20 μm) of nematic liquid crystal (LC). For 4-cyano-4'-pentylbiphenyl droplets decorated with two to five PS colloids, we found 32 distinct arrangements of the colloids to form at the boojums of bipolar droplet configurations. Significantly, all but one of these configurations (a ring comprised of five PS colloids) could be mapped onto a local (non-close packed) hexagonal lattice. To provide insight into the origin of the hexagonal lattice, we investigated planar aqueous-LC interfaces, and found that organized assemblies of PS colloids did not form at these interfaces. Experiments involving the addition of salts revealed that a repulsive interaction of electrostatic origin prevented formation of assemblies at planar interfaces, and that regions of high splay near the poles of the LC droplets generated cohesive interactions between colloids that could overcome the repulsion. Support for this interpretation was obtained from a model that included (i) a long-range attraction between adsorbed colloids and the boojum due to the increasing rate of strain (splay) of LC near the boojum (splay attraction), (ii) an attractive inter-colloid interaction that reflects the quadrupolar symmetry of the strain in the LC around the colloids, and (iii) electrostatic repulsion between colloids. The model predicts that electrostatic repulsion between colloids can lead to a ∼1000kBT energy barrier at planar interfaces of LC films, and that the repulsive interaction can be overcome by splay attraction of the colloids to the boojums of the LC droplets. Overall, the results reported in this paper advance our understanding of the directed assembly of colloids at interfaces of LC droplets.

  7. Electrospinning biopolymers from ionic liquids requires control of different solution properties than volatile organic solvents

    DOE PAGES

    Zavgorodnya, Oleksandra; Shamshina, Julia L.; Bonner, Jonathan R.; ...

    2017-04-27

    Here, we report the correlation between key solution properties and spinability of chitin from the ionic liquid (IL) 1-ethyl-3-methylimidazolium acetate ([C2mim][OAc]), and the similarities and differences to electrospinning solutions of non-ionic polymers in volatile organic compounds (VOCs). We found that when electrospinning is conducted from ILs, conductivity and surface tension are not the key parameters regulating spinability, while solution viscosity and polymer concentration are. Contrarily, for electrospinning of polymers from VOCs, solution conductivity and viscosity have been reported to be among some of the most important factors controlling fiber formation. For chitin electrospun from [C2mim][OAc], we found both a criticalmore » chitin concentration required for continuous fiber formation (> 0.20 wt%) and a required viscosity for the spinning solution (between ca. 450 – 1500 cP). The high viscosities of the biopolymer-IL solutions made it possible to electrospin solutions with low, less than 1 wt% of polymer concentration and produce thin fibers without the need to adjust the electrospinning parameters. These results suggest new prospects for the control of fiber architecture in non-woven mats, which is crucial for materials performance.« less

  8. The influence of interfacial properties on two-phase liquid flow of organic contaminants in groundwater

    SciTech Connect

    Hayes, K.F.; Demond, A.H.

    1991-08-01

    An improved understanding of the factors influencing the movement of a separate organic liquid phase in groundwater aquifers is important to the US Department of Energy's efforts to alleviate groundwater contamination by many common solvents. The overall objective of this project is to investigate how changes in interfacial chemical properties affect two-phase flow relationships. Specifically, the objective is to develop a quantitative theory that will enable the prediction of changes in the capillary pressure-saturation relationship, a fundamental constitutive relationship in multiphase flow modeling, from changes in interfacial properties through a knowledge of their effect on wettability. The work over the past eight months of the project summarized here shows the interrelationship between the surface chemical properties of sorption, electrophoretic mobility, contact angle, surface tension and capillary pressure, and how the effects on capillary pressure might be predicted on the basis of surface tension and contact angle. The model system we have been examining consists of o-xylene, water, silica sand, and cetyltrimethylammonium bromide (CTAB), in which all three interfacial tensions of the system change.

  9. Touch sensors based on planar liquid crystal-gated-organic field-effect transistors

    NASA Astrophysics Data System (ADS)

    Seo, Jooyeok; Lee, Chulyeon; Han, Hyemi; Lee, Sooyong; Nam, Sungho; Kim, Hwajeong; Lee, Joon-Hyung; Park, Soo-Young; Kang, Inn-Kyu; Kim, Youngkyoo

    2014-09-01

    We report a tactile touch sensor based on a planar liquid crystal-gated-organic field-effect transistor (LC-g-OFET) structure. The LC-g-OFET touch sensors were fabricated by forming the 10 μm thick LC layer (4-cyano-4'-pentylbiphenyl - 5CB) on top of the 50 nm thick channel layer (poly(3-hexylthiophene) - P3HT) that is coated on the in-plane aligned drain/source/gate electrodes (indium-tin oxide - ITO). As an external physical stimulation to examine the tactile touch performance, a weak nitrogen flow (83.3 μl/s) was employed to stimulate the LC layer of the touch device. The LC-g-OFET device exhibited p-type transistor characteristics with a hole mobility of 1.5 cm2/Vs, but no sensing current by the nitrogen flow touch was measured at sufficiently high drain (VD) and gate (VG) voltages. However, a clear sensing current signal was detected at lower voltages, which was quite sensitive to the combination of VD and VG. The best voltage combination was VD = -0.2 V and VG = -1 V for the highest ratio of signal currents to base currents (i.e., signal-to-noise ratio). The change in the LC alignment upon the nitrogen flow touch was assigned as the mechanism for the present LC-g-OFET touch sensors.

  10. NMR relaxometric properties and cytotoxicity of Gd2O3 nanoparticle suspensions in an organic liquid

    NASA Astrophysics Data System (ADS)

    Babić-Stojić, Branka; Jokanović, Vukoman; Milivojević, Dušan; Požek, Miroslav; Jagličić, Zvonko; Makovec, Darko; Arsikin, Katarina; Paunović, Verica

    2014-10-01

    Gd2O3 nanoparticles and their agglomerates from approximately 10 to 80 nm in size suspended in an organic liquid were synthesized via polyol route. The reaction between diethylene glycol and added acetic acid, which occurred simultaneously with the synthesis of Gd2O3 nanoparticles, was catalyzed by sodium bisulfate to transform as much as possible diethylene glycol in corresponding ester at the end of complete reaction. The produced nanosized material of gadolinium oxide was investigated by TEM, DLS, FTIR spectroscopy, and NMR relaxometry. Biological evaluation of this material was done by MTT and crystal violet assays to determine the cell viability. Longitudinal and transverse relaxivities of water-diluted Gd2O3 nanoparticle suspensions estimated to be r 1 = 13.6 and r 2 = 14.7 s-1 mM-1 are about three times higher compared to the relaxivities obtained for standard contrast agent Gd-DTPA (Magnevist). Good MRI signal intensities of the water-diluted Gd2O3 nanoparticle suspensions were recorded in the Gd concentration range 0.2-0.3 mM for which the suspensions were not toxic exhibiting simultaneously higher signal intensities than those for Magnevist in the Gd concentration range 0.4-1 mM for which this standard contrast agent was not toxic. These properties make the produced Gd2O3 nanoparticle material promising for potential application as MRI contrast agent.

  11. Formation of a new archetypal Metal-Organic Framework from a simple monatomic liquid

    SciTech Connect

    Metere, Alfredo Oleynikov, Peter; Dzugutov, Mikhail; O’Keeffe, Michael

    2014-12-21

    We report a molecular-dynamics simulation of a single-component system of particles interacting via a spherically symmetric potential that is found to form, upon cooling from a liquid state, a low-density porous crystalline phase. Its structure analysis demonstrates that the crystal can be described by a net with a topology that belongs to the class of topologies characteristic of the Metal-Organic Frameworks (MOFs). The observed net is new, and it is now included in the Reticular Chemistry Structure Resource database. The observation that a net topology characteristic of MOF crystals, which are known to be formed by a coordination-driven self-assembly process, can be reproduced by a thermodynamically stable configuration of a simple single-component system of particles opens a possibility of using these models in studies of MOF nets. It also indicates that structures with MOF topology, as well as other low-density porous crystalline structures can possibly be produced in colloidal systems of spherical particles, with an appropriate tuning of interparticle interaction.

  12. Liquid chromatographic determination of organic nitrogenous bases in dosage forms: a progress report.

    PubMed

    Walker, S T

    1985-01-01

    A liquid chromatographic (LC) method has been developed as a general procedure for the assay of the salts of organic nitrogenous bases in a variety of dosage forms. The method uses a nitrile-bonded reverse phase column, a methanol-0.003M ammonium acetate (90 + 10) mobile phase, and photometric detection at 254 nm. The sample is dissolved in the mobile phase and an aliquot is injected through a 20 microL injection loop. Average recovery values for duplicate assays were chlorpheniramine maleate injection 97.8%, chlorpheniramine maleate tablets 99.1%, cyclizine hydrochloride tablets 100.0%, doxylamine succinate tablets 103.3%, mesoridazine besylate tablets 100.4%, pentazocine hydrochloride tablets 103.0%, promethazine hydrochloride injection 98.4%, protriptyline hydrochloride tablets 101.2%, pyrilamine maleate tablets 97.8%, pyrimethamine tablets 100.0%, tripelennamine citrate elixir 100.0%, and tripelennamine hydrochloride tablets 97.2%. Results by this method were in good agreement with those obtained by the USP XX method. This study, which is being continued, will be expanded to include additional drugs.

  13. Ionic liquid-based zwitterionic organic polymer monolithic column for capillary hydrophilic interaction chromatography.

    PubMed

    Wang, Tingting; Chen, Yihui; Ma, Junfeng; Zhang, Xiaodan; Zhang, Lihua; Zhang, Yukui

    2015-08-21

    In the current study, a novel ionic liquid-based zwitterionic organic polymer monolithic column was developed by copolymerizing 1-vinyl-3-(butyl-4-sulfonate) imidazolium, acrylamide and N,N'-methylenebisacrylamide in a quaternary porogenic solvent consisting of formamide, dimethyl sulphoxide, polyethylene glycol 8000 and polyethylene glycol 10,000 for capillary hydrophilic interaction chromatography. The monolithic stationary phase was optimized by adjusting the amount of monomer in the polymerization solution along with the composition of porogenic solvent. The optimized monolith exhibited excellent selectivity and favorable retention for nucleosides and benzoic acid derivatives. The primary factors affecting the separation efficiency of the monolithic column (including acetonitrile content, pH, and buffer salt concentration in the mobile phase) have been thoroughly evaluated. Excellent reproducibility of the retention times for five nucleosides was achieved, with relative standard deviations of run-to-run (n = 3), column-to-column (n = 3) and batch-to-batch (n = 3) in the range of 0.18-0.48%, 2.33-4.20% and 3.07-6.50%, respectively.

  14. Acute toxicity of ionic liquids for three freshwater organisms: Pseudokirchneriella subcapitata, Daphnia magna and Danio rerio.

    PubMed

    Pretti, Carlo; Chiappe, Cinzia; Baldetti, Ilaria; Brunini, Sara; Monni, Gianfranca; Intorre, Luigi

    2009-05-01

    The static acute toxicities of 18 ionic liquids (ILs) were determined for three representative freshwater organisms, the cladoceran Daphnia magna, the green alga Pseudokirchneriella subcapitata (formerly known as Selenastrum capricornutum), and the fish Danio rerio (formerly known as zebrafish). The test kit compounds contained three widely used ILs (1-butyl-3-methylimidazolium bis(triflimide), [bmim][Tf(2)N], butylpyridinium bis(triflimide), [bpy][Tf(2)N], and N,N-methylbutylpyrrolidinium bis(triflimide), [bmpyrr][Tf(2)N]) and 15 less common salts. These latter comprised a range of five anions, four positively charged head groups (ammonium, morpholinium, thiophenium, and sulfonium), five 1-methyl-3-alkyl imidazolium derivatives bearing a specific functional group on the longer alkyl chain (Cl, OH, or (CH(3))(3)Si) and three imidazolium derivatives characterized by the presence of a hydrogen atom on the imidazolium nitrogen ("Brønsted acidic imidazolium"-based ILs). Generally, long-chain ammonium salts showed higher toxicity to algae, cladocerans, and fish, whereas very low toxicities characterized sulfonium- and morpholinium-based ILs. In imidazolium-based ILs, the substitution of one or two carbon atoms of the longer alkyl chain with a more electronegative atom (chlorine or oxygen) reduced the acute toxicity for algae and cladocerans. Low toxicity also characterized the "Brønsted acidic imidazolium"-based ILs. Structural information for a rational designer of safer ILs can be obtained from these studies.

  15. Ionic Liquid/Metal-Organic Framework Composites: From Synthesis to Applications.

    PubMed

    Kinik, Fatma Pelin; Uzun, Alper; Keskin, Seda

    2017-07-21

    Metal-organic frameworks (MOFs) have been widely studied for different applications owing to their fascinating properties such as large surface areas, high porosities, tunable pore sizes, and acceptable thermal and chemical stabilities. Ionic liquids (ILs) have been recently incorporated into the pores of MOFs as cavity occupants to change the physicochemical properties and gas affinities of MOFs. Several recent studies have shown that IL/MOF composites show superior performances compared with pristine MOFs in various fields, such as gas storage, adsorption and membrane-based gas separation, catalysis, and ionic conductivity. In this review, we address the recent advances in syntheses of IL/MOF composites and provide a comprehensive overview of their applications. Opportunities and challenges of using IL/MOF composites in many applications are reviewed and the requirements for the utilization of these composite materials in real industrial processes are discussed to define the future directions in this field. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Model Catalytic Studies of Novel Liquid Organic Hydrogen Carriers: Indole, Indoline and Octahydroindole on Pt(111).

    PubMed

    Schwarz, Matthias; Bachmann, Philipp; Silva, Thais Nascimento; Mohr, Susanne; Scheuermeyer, Marlene; Späth, Florian; Bauer, Udo; Düll, Fabian; Steinhauer, Johann; Hohner, Chantal; Döpper, Tibor; Noei, Heshmat; Stierle, Andreas; Papp, Christian; Steinrück, H-P; Wasserscheid, Peter; Görling, Andreas; Libuda, Jörg

    2017-08-16

    Indole derivatives were recently proposed as potential liquid organic hydrogen carriers (LOHC) for storage of renewable energies. In this work, we have investigated the adsorption, dehydrogenation and degradation mechanisms in the indole/indoline/octahydroindole system on Pt(111). We have combined infrared reflection absorption spectroscopy (IRAS), X-ray photoelectron spectroscopy (XPS) and DFT calculations. Indole multilayers show a crystallization transition at 200 K, in which the molecules adopt a strongly tilted orientation, before the multilayer desorbs at 220 K. For indoline, a less pronounced restructuring transition occurs at 150 K and multilayer desorption is observed at 200 K. Octahydroindole multilayers desorb already at 185 K, without any indication for restructuring. Adsorbed monolayers of all three compounds are stable up to room temperature and undergo deprotonation at the NH bond above 300 K. For indoline, the reaction is followed by partial dehydrogenation at the 5-membered ring, leading to the formation of a flat-lying di-σ-indolide in the temperature range from 330-390 K. Noteworthy, the same surface intermediate is formed from indole. In contrast, the reaction of octahydroindole with Pt(111) leads to the formation of a different intermediate, which originates from partial dehydrogenation of the 6-membered ring. Above 390 K, all three compounds again form the same strongly dehydrogenated and partially decomposed surface species. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Formation of a new archetypal Metal-Organic Framework from a simple monatomic liquid.

    PubMed

    Metere, Alfredo; Oleynikov, Peter; Dzugutov, Mikhail; O'Keeffe, Michael

    2014-12-21

    We report a molecular-dynamics simulation of a single-component system of particles interacting via a spherically symmetric potential that is found to form, upon cooling from a liquid state, a low-density porous crystalline phase. Its structure analysis demonstrates that the crystal can be described by a net with a topology that belongs to the class of topologies characteristic of the Metal-Organic Frameworks (MOFs). The observed net is new, and it is now included in the Reticular Chemistry Structure Resource database. The observation that a net topology characteristic of MOF crystals, which are known to be formed by a coordination-driven self-assembly process, can be reproduced by a thermodynamically stable configuration of a simple single-component system of particles opens a possibility of using these models in studies of MOF nets. It also indicates that structures with MOF topology, as well as other low-density porous crystalline structures can possibly be produced in colloidal systems of spherical particles, with an appropriate tuning of interparticle interaction.

  18. Solid-liquid extraction of alkali metals and organic compounds by leaching of food industry residues.

    PubMed

    Yu, Chaowei; Zheng, Yi; Cheng, Yu-Shen; Jenkins, Bryan M; Zhang, Ruihong; VanderGheynst, Jean S

    2010-06-01

    Leaching was studied for its application in extracting inorganic and organic constituents from fresh fermented grape pomace, air-dried fermented grape pomace and air-dried sugar beet pulp. Samples of each feedstock were leached in water at ambient temperature for 30 or 120 min at dry solid-to-liquid ratios of 1/20 and 1/50 kg/L. Leaching removed 82% of sodium, 86% of potassium, and 76% of chlorine from sugar beet pulp, and reduced total ash concentration in air-dry fermented grape pomace from 8.2% to 2.9% of dry matter, 8.2% to 4.4% in fresh fermented grape pomace, and 12.5% to 5.4% in sugar beet pulp. Glycerol (7-11 mg/dry g), ethanol (131-158 mg/dry g), and acetic acid (24-31 mg/dry g) were also extracted from fermented grape pomace. These results indicate that leaching is a beneficial pretreatment step for improving the quality of food processing residues for thermochemical and biochemical conversion.

  19. A novel series of isoreticular metal organic frameworks: realizing metastable structures by liquid phase epitaxy

    PubMed Central

    Liu, Jinxuan; Lukose, Binit; Shekhah, Osama; Arslan, Hasan Kemal; Weidler, Peter; Gliemann, Hartmut; Bräse, Stefan; Grosjean, Sylvain; Godt, Adelheid; Feng, Xinliang; Müllen, Klaus; Magdau, Ioan-Bogdan; Heine, Thomas; Wöll, Christof

    2012-01-01

    A novel class of metal organic frameworks (MOFs) has been synthesized from Cu-acetate and dicarboxylic acids using liquid phase epitaxy. The SURMOF-2 isoreticular series exhibits P4 symmetry, for the longest linker a channel-size of 3 × 3 nm2 is obtained, one of the largest values reported for any MOF so far. High quality, ab-initio electronic structure calculations confirm the stability of a regular packing of (Cu++)2- carboxylate paddle-wheel planes with P4 symmetry and reveal, that the SURMOF-2 structures are in fact metastable, with a fairly large activation barrier for the transition to the bulk MOF-2 structures exhibiting a lower, twofold (P2 or C2) symmetry. The theoretical calculations also allow identifying the mechanism for the low-temperature epitaxial growth process and to explain, why a synthesis of this highly interesting, new class of high-symmetry, metastable MOFs is not possible using the conventional solvothermal process. PMID:23213357

  20. High internal ionic liquid phase emulsion stabilized by metal-organic frameworks.

    PubMed

    Li, Zhihao; Zhang, Jianling; Luo, Tian; Tan, Xiuniang; Liu, Chengcheng; Sang, Xinxin; Ma, Xue; Han, Buxing; Yang, Guanying

    2016-11-04

    The emulsification of metal-organic frameworks (MOFs) for the two immiscible phases of water and ionic liquid (IL) was investigated for the first time. It was found that Ni-BDC (BDC = 1,4-dicarboxybenzene) can emulsify water and ILs and favor the formation of high internal phase emulsions (HIPEs) under certain experimental conditions. The microstructures of the HIPEs were characterized by confocal laser scanning microscopy using a fluorescent dye Rhodamine B, which proves that the HIPEs are the IL-in-water type. Further results reveal that the HIPE forms during the IL-in-water to water-in-IL emulsion inversion. The possibilities of the HIPE formation by other MOFs (Cu-BDC and Zn-BDC) were explored and the mechanism for HIPE formation was discussed. The MOF-stabilized HIPE was applied to the in situ synthesis of a MOF/polymer composite by HIPE polymerization. The macroporous MOF/polyacrylamide network and MOF/polystyrene microspheres were obtained from the HIPEs, respectively.

  1. Formation of a new archetypal Metal-Organic Framework from a simple monatomic liquid

    NASA Astrophysics Data System (ADS)

    Metere, Alfredo; Oleynikov, Peter; Dzugutov, Mikhail; O'Keeffe, Michael

    2014-12-01

    We report a molecular-dynamics simulation of a single-component system of particles interacting via a spherically symmetric potential that is found to form, upon cooling from a liquid state, a low-density porous crystalline phase. Its structure analysis demonstrates that the crystal can be described by a net with a topology that belongs to the class of topologies characteristic of the Metal-Organic Frameworks (MOFs). The observed net is new, and it is now included in the Reticular Chemistry Structure Resource database. The observation that a net topology characteristic of MOF crystals, which are known to be formed by a coordination-driven self-assembly process, can be reproduced by a thermodynamically stable configuration of a simple single-component system of particles opens a possibility of using these models in studies of MOF nets. It also indicates that structures with MOF topology, as well as other low-density porous crystalline structures can possibly be produced in colloidal systems of spherical particles, with an appropriate tuning of interparticle interaction.

  2. A molecular nematic liquid crystalline material for high-performance organic photovoltaics

    PubMed Central

    Sun, Kuan; Xiao, Zeyun; Lu, Shirong; Zajaczkowski, Wojciech; Pisula, Wojciech; Hanssen, Eric; White, Jonathan M.; Williamson, Rachel M.; Subbiah, Jegadesan; Ouyang, Jianyong; Holmes, Andrew B.; Wong, Wallace W.H.; Jones, David J.

    2015-01-01

    Solution-processed organic photovoltaic cells (OPVs) hold great promise to enable roll-to-roll printing of environmentally friendly, mechanically flexible and cost-effective photovoltaic devices. Nevertheless, many high-performing systems show best power conversion efficiencies (PCEs) with a thin active layer (thickness is ~100 nm) that is difficult to translate to roll-to-roll processing with high reproducibility. Here we report a new molecular donor, benzodithiophene terthiophene rhodanine (BTR), which exhibits good processability, nematic liquid crystalline behaviour and excellent optoelectronic properties. A maximum PCE of 9.3% is achieved under AM 1.5G solar irradiation, with fill factor reaching 77%, rarely achieved in solution-processed OPVs. Particularly promising is the fact that BTR-based devices with active layer thicknesses up to 400 nm can still afford high fill factor of ~70% and high PCE of ~8%. Together, the results suggest, with better device architectures for longer device lifetime, BTR is an ideal candidate for mass production of OPVs. PMID:25586307

  3. Effect of Turning Frequency on Composting of Empty Fruit Bunches Mixed with Activated Liquid Organic Fertilizer

    NASA Astrophysics Data System (ADS)

    Trisakti, B.; Lubis, J.; Husaini, T.; Irvan

    2017-03-01

    Composting of Empty Fruit Bunch (EFB) by mixing it with activated liquid organic fertilizer (ALOF) is an alternative way in the utilization of solid waste produced from the palm oil mill (POM). This research was to determine the effect of turning frequency on the rate of composting of EFB mixed with ALOF in a basket composter. The composting process was started with cutting the EFB into pieces with size 1-3 cm, inserting the EFB pieces into basket composter (33 cm W × 28 cm L × 40 cm H), and adding ALOF until moisture content (MC) in the range of 55-65%. During composting, the MC was maintained at 55-65% range by adding the ALOF. The turning frequency on each composter was varied i.e. once in every 1, 2, 3, 4, and 5 days. The parameters analysed during composting were temperature, pH, MC, compost weight, water holding capacity (WHC), CN ratio, and the quality of the final compost. Composting was carried out for 40 days and the best result obtained at turning frequency was 3 days. The best compost characteristic was pH 9.0; MC 57.24%; WHC 76%; CN ratio 12.15%; P 0.58%; and K 0. 95%.

  4. [Effects of organic fish protein liquid fertilizer on enzyme activities and microbial biomass C and N in a silt soil].

    PubMed

    Wei, Xiu-Li; Lei, Ping; Shi, Wei-Yong

    2010-08-01

    By the method of thermostatic culture, this paper studied the effects of different application rates (0.5, 1.5, and 2.5 ml x kg(-1)) of organic fish protein liquid fertilizer on the enzyme activities and microbial biomass C and N in a silt soil, and the relationships between these parameters and soil nutrient contents. Under the application of the liquid fertilizer, soil pH varied in the range of 7.07-7.31, but had no significant difference from the control. With the increasing application rate of the liquid fertilizer, the activities of soil phosphatase, urease, and protease, as well as the soil biomass C and N, all increased significantly, and the increment was 127, 190 and 196%, 39.81, 78.06 and 173.24%, 56.37, 108.29 and 199.98%, 167, 395 and 474%, and 121, 243 and 406%, respectively, compared with the control. The peak time of the soil urease and protease activities and microbial biomass C and N differed with the fertilization treatments. Soil phosphase, urease, and protease activities and microbial biomass C and N were significantly positively correlated with soil nutrient contents, suggesting that applying organic fish protein liquid fertilizer to silt soil could improve soil microbial growth and enzyme activities, and accordingly, promote the decomposition and transformation of soil organic matter and the release of soil available nutrient elements.

  5. In-line cold column trapping of organic phase in dispersive liquid-liquid microextraction: enrichment and determination of curcumin in human serum.

    PubMed

    Safdarian, Mehdi; Hashemi, Payman; Naderlou, Malihe

    2012-06-29

    A new temperature controlled cold column trapping (CCT) system was developed for in-line sequestration of organic phase in dispersive liquid-liquid microextraction (DLLME) method. In the developed CCT-DLLME method, the dispersed organic extraction phase is solidified and trapped in the CCT, packed with glass particles. Subsequently, the sequestered phase is washed out in an elevated temperature by using an appropriate solvent. The column temperature is controlled by a pair of thermal electric cooler (TEC) plates. The new device is simple and portable and can eliminate the need for centrifugation in the DLLME method for solvents with an appropriate melting point. Some important parameters such as types of extraction and disperser solvents and their volumes, minimum and maximum column temperatures and extraction time were optimized for the extraction of curcumin, as a model compound. Using 1-dodecanol as the organic solvent and acetone as the disperser, recoveries exceeding 90% and a relative standard deviation of 2.87% were obtained for 5 replicated analyses of curcumin by an HPLC method. The detection limit of curcumin (3σ) extracted by the CCT-DLLME system was 28 μg L⁻¹. The method was successfully applied to the determination of curcumin in some human serum samples.

  6. Nontargeted lipidomic characterization of porcine organs using hydrophilic interaction liquid chromatography and off-line two-dimensional liquid chromatography-electrospray ionization mass spectrometry.

    PubMed

    Cífková, Eva; Holčapek, Michal; Lísa, Miroslav

    2013-09-01

    Lipids form a significant part of animal organs and they are responsible for important biological functions, such as semi-permeability and fluidity of membranes, signaling activity, anti-inflammatory processes, etc. We have performed a comprehensive nontargeted lipidomic characterization of porcine brain, heart, kidney, liver, lung, spinal cord, spleen, and stomach using hydrophilic interaction liquid chromatography (HILIC) coupled to electrospray ionization mass spectrometry (ESI/MS) to describe the representation of individual lipid classes in these organs. Detailed information on identified lipid species inside classes are obtained based on relative abundances of deprotonated molecules [M-H](-) in the negative-ion ESI mass spectra, which provides important knowledge on phosphatidylethanolamines and their different forms of fatty acyl linkage (ethers and plasmalogens), phosphatidylinositols, and hexosylceramides containing nonhydroxy- and hydroxy-fatty acyls. The detailed analysis of identified lipid classes using reversed-phase liquid chromatography in the second dimension was performed for porcine brain to determine more than 160 individual lipid species containing attached fatty acyls of different acyl chain length, double-bond number, and positions on the glycerol skeleton. The fatty acid composition of porcine organs is determined by gas chromatography with flame ionization detection after the transesterification with sodium methoxide.

  7. Rotational Diffusion of Charged and Nondipolar Solutes in Ionic Liquid-Organic Solvent Mixtures: Evidence for Stronger Specific Solute-Solvent Interactions in Presence of Organic Solvent.

    PubMed

    Prabhu, Sugosh R; Dutt, G B

    2015-08-20

    Rotational diffusion of a charged solute, rhodamine 110 (R110), and a nondipolar solute, 2,5-dimethyl-1,4-dioxo-3,6-diphenylpyrrolo[3,4-c]pyrrole (DMDPP), has been investigated in ionic liquids, 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([BMIM][Tf2N]) and 1-butyl-3-methylimidazolium tris(pentafluoroethyl)trifluorophosphate ([BMIM][FAP]), with 0.8 mole fraction of dibenzyl ether (DBE). This study has been undertaken to find out how specific interactions between the solute and the ionic liquid are affected upon dilution with a nondipolar solvent. It has been observed that at a given viscosity (η) and temperature (T), the reorientation times of R110 increase by 40-60% in the ionic liquid-organic solvent mixtures compared to ones in the corresponding neat ionic liquids. In the case of DMDPP, the influence of DBE is less pronounced, and its reorientation times increase by 25-50% at a given η/T. The addition of DBE weakens the numerous interactions prevailing between the cations and the anions of the ionic liquids, which results in stronger specific interactions between the solutes and the constituent ions, consequently leading to slower rotation of the solutes.

  8. Production of 15N-Labelled Liquid Organic Fertilisers Based on Manure and Crop Residue for Use in Fertigation Studies.

    PubMed

    Martínez-Alcántara, Belén; Martínez-Cuenca, Mary-Rus; Fernández, Carlos; Legaz, Francisco; Quiñones, Ana

    2016-01-01

    Large quantities of crop residue and animal manure from agricultural and livestock activities are annually produced worldwide. With proper management, these residues are potentially valuable sources of plant nutrients, mainly N. Recycling such subproducts in sustainably-based agricultural systems can minimise the use of mineral fertilisers, and hence reduce the potential risk of surface and groundwater pollution. Therefore, the purpose of this study was to obtain (small scale) two liquid labelled-organic fertilisers, an animal- and a vegetal-based organic (AO and VO, respectively) fertiliser, to be used as organic N sources in subsequent fertigation studies. Forage maize (Zea mays L.) grown under 15N-labelled fertiliser supply was used as raw material for VO fertiliser production, and also as 15N-labelled sheep feed to obtain 15N-labelled manure. The labelled faeces fraction was used as raw material for the AO fertiliser. The VO fertiliser was obtained after an acidic and an enzyme-driven hydrolysis. The AO fertiliser was obtained after acidic hydrolysis. The VO liquid fertiliser presented an N concentration of 330 mg·L-1, 85% of total N was organic, while ammonium and nitrate N accounted for 55% and 45% of the mineral nitrogen fraction, respectively. This fertiliser also exhibited high K, Ca and S concentrations and notable values for the remaining macro- and micronutrients. The AO liquid fertiliser had a similar total N concentration (496 mg·L-1, 82% of total N in an organic form) to that of VO, but its mineral N fraction significantly differed, which came in a predominantly (95%) ammonia form. It also had a high content of N, P, K and other macronutrients, and sufficient Fe, Zn, Mn, Cu and B levels, which suggests its suitability as a potential fertiliser. The percentage of 15N enrichment in both VO and AO liquid fertilisers exceeded 2% 15N atom excess, which enabled their use in subsequent assays run to assess nitrogen uptake efficiency.

  9. Solid-phase extraction assisted dispersive liquid-liquid microextraction based on solidification of floating organic droplet to determine sildenafil and its analogues in dietary supplements.

    PubMed

    Li, Jing; Roh, Si Hun; Shaodong, Jia; Hong, Ji Yeon; Lee, Dong-Kyu; Shin, Byong-Kyu; Park, Jeong Hill; Lee, Jeongmi; Kwon, Sung Won

    2017-08-01

    A novel analytical method for the simultaneous determination of the concentration of sildenafil and its five analogues in dietary supplements using solid-phase extraction assisted reversed-phase dispersive liquid-liquid microextraction based on solidification of floating organic droplet combined with ion-pairing liquid chromatography with an ultraviolet detector was developed. Parameters that affect extraction efficiency were systematically investigated, including the type of solid-phase extraction cartridge, pH of the extraction environment, and the type and volume of extraction and dispersive solvent. The method linearity was in the range of 5.0-100 ng/mL for sildenafil, homosildenafil, udenafil, benzylsildenafil, and thiosildenafil and 10-100 ng/mL for acetildenafil. The coefficients of determination were ≥0.996 for all regression curves. The sensitivity values expressed as limit of detection were between 2.5 and 7.5 ng/mL. Furthermore, intraday and interday precisions expressed as relative standard deviations were less than 5.7 and 9.9%, respectively. The proposed method was successfully applied to the analysis of sildenafil and its five analogues in complex dietary supplements. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Fertilization with liquid digestate in organic farming - effects on humus balance, soil potassium contents and soil physical properties

    NASA Astrophysics Data System (ADS)

    Erhart, Eva; Siegl, Thomas; Bonell, Marion; Unterfrauner, Hans; Peticzka, Robert; Ableidinger, Christoph; Haas, Dieter; Hartl, Wilfried

    2014-05-01

    Biogas production and use of liquid digestate are subject of controversial discussion in organic farming. Using biomass from intercrops as feedstock for biogas production makes it possible to produce renewable energy without compromising food production. With liquid digestate, crops can be fertilized in a more targeted way than by incorporating intercrop biomass into the soil. For long-term sustainability in organic farming, however, this practice must not have adverse effects on soil fertility. In order to assess the effects of fertilization with liquid digestate on soil fertility, two randomised field experiments were conducted for two years on different soil types near Bruck/Leitha (Lower Austria). One experiment was set up on a calcareous chernozem with 4 % humus content, the other on a parachernozem with pH 5.9 and 2.1 % humus. Soil potassium content, both in the water-soluble fraction and in the exchangeable fraction, increased significantly at both sites. As fertilization with liquid digestate exceeded the potassium requirements of the crops by far, the proportion of potassium of the exchangeable cations increased rapidly. Soil physical properties were not influenced by digestate fertilization on the chernozem site. On the parachernozem, aggregate stability was increased by the organic matter applied via digestate. On this acidic site low in humus content, the supply of 4 t/ha organic matter, which featured a lignin content of 37 % and was relatively resistant to decomposition, had a clearly positive impact on soil physical properties. Humus balances were computed both with the 'Humuseinheiten'-method and with the site-adapted method STAND. They were calculated on the basis of equal amounts of intercrop biomass either left on the field as green manure or used for biogas production and the resulting amount of liquid digestate brought back to the field. The humus balances indicated that the humus-efficacy of the liquid digestate was equal to slightly higher

  11. Investigation of a Particle into Liquid Sampler to Study the Formation & Ageing of Secondary Organic Aerosol

    NASA Astrophysics Data System (ADS)

    Pereira, K. L.; Hamilton, J. F.; Rickard, A. R.; Bloss, W. J.; Alam, M. S.; Camredon, M.; Munoz, A.; Vazquez, M.; Rodenas, M.; Vera, T.; Borrás, E.

    2012-12-01

    The atmospheric oxidation of Volatile Organic Compounds (VOCs) in the presence of NOx results in the formation of tropospheric ozone and Secondary Organic Aerosol (SOA) [Hallquist et al., 2009]. Whilst SOA is known to affect both climate and human health, the VOC oxidation pathways leading to SOA formation are poorly understood [Solomon et al., 2007]. This is in part due to the vast number and the low concentration of SOA species present in the ambient atmosphere. It has been estimated as many as 10,000 to 100,000 VOCs have been detected in the atmosphere, all of which can undergo photo-chemical oxidation and contribute to SOA formation [Goldstein and Galbally, 2007]. Atmospheric simulation chambers such as the EUropean PHOtoREactor (EUPHORE) in Valencia, Spain, are often used to study SOA formation from a single VOC precursor under controlled conditions. SOA composition and formation can be studied using online techniques such as Aerosol Mass Spectrometry (AMS), which provide high time resolution but limited structural information [Zhang et al., 2007]. Offline techniques, such as collection onto filters, extraction and subsequent analysis, provide detailed SOA composition but only usually one or two samples per experiment. In this work we report time resolved SOA composition analysis using a Particle into Liquid Sampler (PILS) followed by Liquid Chromatography Ion-Trap Mass Spectrometry (LC-IT-MS/MS) and Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FTICR-MS/MS). Experiments were performed at EUPHORE investigating the formation and composition of Methyl Chavicol SOA. Methyl Chavicol (also known as Estragole) was identified as the highest floral emission from an oil palm plantation in Malaysian Borneo and has also been observed in US pine forests [Bouvier-Brown et al., 2009; Misztal et al., 2010]. Previous studies indicate a high SOA yield from Methyl Chavicol at around 40 % [Lee et al., 2006], however currently there have been very few literature

  12. Deep-blue light emission with a wide-bandgap naphthalene-derivative liquid organic semiconductor host

    NASA Astrophysics Data System (ADS)

    Kobayashi, Naofumi; Kuwae, Hiroyuki; Oshima, Juro; Ishimatsu, Ryoichi; Tashiro, Shuya; Imato, Toshihiko; Adachi, Chihaya; Shoji, Shuichi; Mizuno, Jun

    2017-02-01

    We developed a novel naphthalene-derivative to function as a wide-bandgap liquid organic semiconductor (LOS) host material for the limited range of liquid deep-blue light-emitting materials that have been developed to date. The naphthalene-derivative, 1-naphthaleneacetic acid 2-ethylhexyl ester (NLQ) was synthesized as a LOS, by introducing an ethylhexyl group into naphthalene. 9,10-Diphenyl anthracene (DPA) was doped into NLQ as a guest deep-blue dye. From the absorption spectrum, the bandgap energy of NLQ was estimated to be 4.13 eV, indicating that NLQ has the widest bandgap energy of any such host material so far as we know. Deep-blue electroluminescence (EL) emission in a liquid state was obtained by doping DPA into NLQ. Light emission could be achieved by a combination of Förster resonance energy transfer and direct recombination of trapped holes and electrons because the bandgap energy of DPA is straddle by that of the wide-bandgap NLQ. Thus, NLQ is shown to be a promising wide-bandgap LOS host material, which allows deep-blue light emission and may have applications in liquid organic light-emitting diodes.

  13. Touch sensors based on planar liquid crystal-gated-organic field-effect transistors

    SciTech Connect

    Seo, Jooyeok; Lee, Chulyeon; Han, Hyemi; Lee, Sooyong; Nam, Sungho; Kim, Youngkyoo; Kim, Hwajeong; Lee, Joon-Hyung; Park, Soo-Young; Kang, Inn-Kyu

    2014-09-15

    We report a tactile touch sensor based on a planar liquid crystal-gated-organic field-effect transistor (LC-g-OFET) structure. The LC-g-OFET touch sensors were fabricated by forming the 10 μm thick LC layer (4-cyano-4{sup ′}-pentylbiphenyl - 5CB) on top of the 50 nm thick channel layer (poly(3-hexylthiophene) - P3HT) that is coated on the in-plane aligned drain/source/gate electrodes (indium-tin oxide - ITO). As an external physical stimulation to examine the tactile touch performance, a weak nitrogen flow (83.3 μl/s) was employed to stimulate the LC layer of the touch device. The LC-g-OFET device exhibited p-type transistor characteristics with a hole mobility of 1.5 cm{sup 2}/Vs, but no sensing current by the nitrogen flow touch was measured at sufficiently high drain (V{sub D}) and gate (V{sub G}) voltages. However, a clear sensing current signal was detected at lower voltages, which was quite sensitive to the combination of V{sub D} and V{sub G}. The best voltage combination was V{sub D} = −0.2 V and V{sub G} = −1 V for the highest ratio of signal currents to base currents (i.e., signal-to-noise ratio). The change in the LC alignment upon the nitrogen flow touch was assigned as the mechanism for the present LC-g-OFET touch sensors.

  14. Graphene-based supercapacitors in the parallel-plate electrode configuration: ionic liquids versus organic electrolytes.

    PubMed

    Shim, Youngseon; Kim, Hyung J; Jung, Younjoon

    2012-01-01

    Supercapacitors with two single-sheet graphene electrodes in the parallel plate geometry are studied via molecular dynamics (MD) computer simulations. Pure 1-ethyl-3-methylimidazolium tetrafluoroborate (EMI+BF4-) and a 1.1 M solution of EMI+BF4- in acetonitrile are considered as prototypes of room-temperature ionic liquids (RTILs) and organic electrolytes. Electrolyte structure, charge density and associated electric potential are investigated by varying the charges and separation of the two electrodes. Multiple charge layers formed in the electrolytes in the vicinity of the electrodes are found to screen the electrode surface charge almost completely. As a result, the supercapacitors show nearly an ideal electric double layer behavior, i.e., the electric potential exhibits essentially a plateau behavior in the entire electrolyte region except for sharp changes in screening zones very close to the electrodes. Due to its small size and large charge separation, BF4- is considerably more efficient in shielding electrode charges than EMI+. In the case of the acetonitrile solution, acetonitrile also plays an important role by aligning its dipoles near the electrodes; however, the overall screening mainly arises from ions. Because of the disparity of shielding efficiency between cations and anions, the capacitance of the positively-charged anode is significantly larger than that of the negatively-charged cathode. Therefore, the total cell capacitance in the parallel plate configuration is primarily governed by the cathode. Ion conductivity obtained via the Green-Kubo (GK) method is found to be largely independent of the electrode surface charge. Interestingly, EMI+BF4- shows higher GK ion conductivity than the 1.1 M acetonitrile solution between two parallel plate electrodes.

  15. Analysis of the organic liquid produced from catalytic cracking of crude palm oil in the presence of alumina supported catalysts

    NASA Astrophysics Data System (ADS)

    Ramli, Anita; Razak, Rozlina Abdul

    2012-09-01

    Catalytic cracking of crude palm oil (CPO) was studied in the presence of alumina, 1% Pt/Al2O3 and 1% Pd/Al2O3 as catalyst. The CPO to catalyst weight ratio used was 1:0.05. The experiment was carried out in a simple liquid-phase batch reactor at atmospheric pressure where the sample was heated to 300-350 δC. Products formed were organic liquid products (OLP) and gaseous product with the solid residue remains in the reactor. The total conversion of CPO was only between 25 - 31% where the residue is suggested to be mainly of polimerised CPO. The OLP was analysed using a gas chromatography with FID detector. Analyses show that the selectivity to liquid fuel is influence by the catalyst used whereby Al2O3 gives the highest selectivity to gasoline while 1% Pt/Al2O3 has the highest selectivity to diesel. However, 1% Pd/Al2O3 is not a suitable catalyst for catalytic cracking of CPO to liquid fuel where less than 17.5% of OLP produced could be classified as liquid fuel.

  16. Anomalously slow relaxation of the system of strongly interacting liquid clusters in a disordered nanoporous medium: Self-organized criticality

    NASA Astrophysics Data System (ADS)

    Borman, V. D.; Tronin, V. N.

    2016-09-01

    It has been shown that changes in the energy of a system of nonwetting liquid clusters confined in a random nanoporous medium in the process of relaxation can be written in the quasiparticle approximation in the form of the sum of the energies of local (metastable) configurations of liquid clusters interacting with clusters in the connected nearest pores. The energy spectrum and density of states of the local configuration have been calculated. It has been shown that the relaxation of the state of the system occurs through the scenario of self-organized criticality (SOC). The process is characterized by the expectation of a fluctuation necessary for overcoming a local energy barrier of the metastable state with the subsequent rapid hydrodynamic extrusion of the liquid under the action of the surface buoyancy forces of the nonwetting framework. In this case, the dependence of the interaction between local configurations on the number of filled pores belonging to the infinite percolation cluster of filled pores serves as an internal feedback initiating the SOC process. The calculations give a power-law time dependence of the relative volume of the confined liquid θ ∼t-α(α ∼ 0.1) . The developed model of the relaxation of the porous medium with the nonwetting liquid demonstrates possible mechanisms and scenarios of SOC for disordered atomic systems.

  17. Evaluation of the water and organic liquids extraction efficiency of Spirulina maxima dyes using thermostated micro thin-layer chromatography.

    PubMed

    Zarzycki, Paweł K; Zarzycka, Magdalena B

    2008-01-01

    Thermostated micro thin-layer chromatography was applied for separation and quantification studies of Spirulina maxima dyes isolated from pharmaceutical formulation by a simple one-step liquid extraction. The isolation process was performed using a number of liquids, including water; 10 mM water solutions of native alpha-, beta-, and gamma-cyclodextrin and their hydroxypropyl derivatives; and a number of common organic liquids characterized by different polarity, namely, methanol, ethanol, 1-propanol, 2-propanol, acetonitrile, acetone, tetrahydrofuran, dichloromethane, toluene, and n-hexane. Chromatographic studies were performed on RP18W plates working inside a small thermostated horizontal chamber allowing a development distance of 45 mm. Using a mobile phase consisting of acetone-n-hexane (30 + 70, v/v) and 40 degrees C separation temperature, plate peak capacity of at least 15 spots/lane and developing time <5 min were obtained. Validation data indicated that under such conditions, with an office scanner used for chromatogram digitalization, spot quantification could be accurately performed within an analyte mass range of 2 factors. The raw quantitative data obtained from microchromatograms acquired under visible light conditions were explored using cluster analysis and principal components analysis. Chemometric investigations revealed that the best extraction liquids for isolation of dye mixtures from Spirulina samples were methanol, ethanol, tetrahydrofuran, and dichloromethane. Moreover, it was found that the liquids' parachor values could be used for estimation of the dye extraction efficiency from complex samples.

  18. Very Low-Voltage Operation of Ionic Liquid-Gated n-Type Organic Field-Effect Transistors

    NASA Astrophysics Data System (ADS)

    Uemura, Takafumi; Yamagishi, Masakazu; Ono, Shimpei; Takeya, Jun

    2010-01-01

    n-Type organic field-effect transistors are operated with high transconductance at very low gate voltage using ionic-liquid electrolyte for the gating layers. Tetracyanoquinodimethane single crystals and C60 thin films are respectively interfaced with ionic liquid of 1-ethyl-3-methyl-imidazolium bis(trifluoromethanesulfonyl)imide known for its low viscosity and high ionic conductivity, so that high-density electrons are rapidly accumulated in the semiconductor surfaces. The transistors are gated by high electric field confined to a molecular scale Helmholtz layer with the application of minimum gate voltages. The high-transconductance single-crystal device exhibits excellent air stability and the C60 thin-film transistor has realized the highest normalized transconductance among reported n-type organic transistors, together with remarkable improvement in threshold voltage as compared with that in conventional SiO2 devices.

  19. Poly(ethylene glycol)-based ionic liquids: properties and uses as alternative solvents in organic synthesis and catalysis.

    PubMed

    Cecchini, Martina Maya; Charnay, Clarence; De Angelis, Francesco; Lamaty, Frédéric; Martinez, Jean; Colacino, Evelina

    2014-01-01

    PEG-based ionic liquids are a new appealing group of solvents making the link between two distinct but very similar fluids: ionic liquids and poly(ethylene glycol)s. They find applications across a range of innumerable disciplines in science, technology, and engineering. In the last years, the possibility to use these as alternative solvents for organic synthesis and catalysis has been increasingly explored. This Review highlights strategies for their synthesis, their physical properties (critical point, glass transition temperature, density, rheological properties), and their application in reactions catalyzed by metals (such as Pd, Cu, W, or Rh) or as organic solvent (for example for multicomponent reactions, organocatalysis, CO2 transformation) with special emphasis on their toxicity, environmental impact, and biodegradability. These aspects, very often neglected, need to be considered in addition to the green criteria usually considered to establish ecofriendly processes.

  20. QuEChERS followed by dispersive liquid-liquid microextraction based on solidification of floating organic droplet method for organochlorine pesticides analysis in fish.

    PubMed

    Wang, Xiao-Chen; Shu, Bin; Li, Shan; Yang, Zhao-Guang; Qiu, Bo

    2017-01-01

    A fast, sensitive and environmental-friendly method was developed to determine 13 organochlorine pesticides in fish tissue through gas chromatography with electron capture detection. Sample was extracted initially by acetonitrile and then concentrated through dispersive liquid-liquid microextraction based on solidification of floating organic droplet (DLLME-SFO). Dispersive solid phase extraction (d-SPE) was not a separate step but integrated to DLLME-SFO procedure. In order to separate the d-SPE sorbent, water and organic phase well, a modification to the glass centrifuge tube was made to achieving high centrifugal speed. The optimized method was validated with recoveries ranging from 88.1% to 121.2% (with relative standard deviations <15%) at three spiked levels for all of the pesticides. Good linearity was achieved at seven concentration levels from 6.25 to 625μgL(-1), which corresponded to 0.001-0.100mgkg(-1) in the sample. The limits of quantification and the limits of detection for 13 OCPs ranged from 1.94×10(-3) to 4.93×10(-3)mgkg(-1) and 6.50×10(-4) to 1.58×10(-3)mgkg(-1), respectively. The method was successfully applied to analyze real fish samples.

  1. Employing `Liquid Gap' Transistors to Examine the Mobility-Carrier Density Relation in Polymer and Single Crystal Organic Semiconductors

    NASA Astrophysics Data System (ADS)

    Frisbie, Daniel

    2009-03-01

    It is generally known that the carrier mobility in organic semiconductors can depend on carrier density, but the precise relationship hinges on the degree of structural order and the dielectric polarizability at the organic/dielectric interface. We have fabricated both single crystal and polymer transistors using the PDMS stamp approach pioneered by Podzorov and Rogers [1], where we have replaced the usual `air gap' in these structures with liquids having different dielectric constants. This structure allows us to examine transport in single crystals and polymer semiconductors as a function of tunable dielectric constant and also charge density. We find striking differences in transport behavior for organic single crystals versus polymer semiconductor films using these liquid dielectric transistors. For organic single crystals such as rubrene, the carrier mobility does not seem to be a function of charge density but does strongly depend on the liquid dielectric constant, in keeping with previous results reported by Morpurgo [2] on the effects of dielectric polarizability. For polymer semiconductors, the effect of charge density is overwhelming; there is a strong increase in charge mobility with increasing carrier concentration, following a power law. These results are already largely known, but the `liquid gap' transistors provide a convenient testbed for examining these effects side-by-side for different materials in the same device. We will describe the device fabrication and the nature of our results, as well as discuss the origins of the very different behavior for single crystals versus polymer semiconductor films. 1) Sundar, V.C., et al. Science 303 (2004) 1643. 2) Hulea, I. N., et al. Nature Mater. 5 (2006) 982.

  2. Microextraction techniques coupled to liquid chromatography with mass spectrometry for the determination of organic micropollutants in environmental water samples.

    PubMed

    Padrón, Ma Esther Torres; Afonso-Olivares, Cristina; Sosa-Ferrera, Zoraida; Santana-Rodríguez, José Juan

    2014-07-16

    Until recently, sample preparation was carried out using traditional techniques, such as liquid-liquid extraction (LLE), that use large volumes of organic solvents. Solid-phase extraction (SPE) uses much less solvent than LLE, although the volume can still be significant. These preparation methods are expensive, time-consuming and environmentally unfriendly. Recently, a great effort has been made to develop new analytical methodologies able to perform direct analyses using miniaturised equipment, thereby achieving high enrichment factors, minimising solvent consumption and reducing waste. These microextraction techniques improve the performance during sample preparation, particularly in complex water environmental samples, such as wastewaters, surface and ground waters, tap waters, sea and river waters. Liquid chromatography coupled to tandem mass spectrometry (LC/MS/MS) and time-of-flight mass spectrometric (TOF/MS) techniques can be used when analysing a broad range of organic micropollutants. Before separating and detecting these compounds in environmental samples, the target analytes must be extracted and pre-concentrated to make them detectable. In this work, we review the most recent applications of microextraction preparation techniques in different water environmental matrices to determine organic micropollutants: solid-phase microextraction SPME, in-tube solid-phase microextraction (IT-SPME), stir bar sorptive extraction (SBSE) and liquid-phase microextraction (LPME). Several groups of compounds are considered organic micropollutants because these are being released continuously into the environment. Many of these compounds are considered emerging contaminants. These analytes are generally compounds that are not covered by the existing regulations and are now detected more frequently in different environmental compartments. Pharmaceuticals, surfactants, personal care products and other chemicals are considered micropollutants. These compounds must be

  3. Observing the Growth of Metal-Organic Frameworks by In-Situ Liquid Cell Transmission Electron Microscopy

    SciTech Connect

    Patterson, Joseph P.; Abellan Baeza, Patricia; Denny, Michael S.; Park, Chiwoo; Browning, Nigel D.; Cohen, Seth M.; Evans, James E.; Gianneschi, Nathan C.

    2015-06-17

    Liquid Cell Transmission Electron Microscopy (LCTEM) can provide direct observations of solution phase nanoscale materials, and holds great promise as a tool for monitoring dynamic self assembly processes. Control over particle behavior within the liquid cell, and under electron beam irradiation, is of paramount importance for this technique to contribute to our understanding of chemistry and materials science at the nanoscale. However, this type of control has not been demonstrated for complex, organic macromolecular materials, which form the basis for all biological systems, all of polymer science, and encompass important classes of advanced porous materials. Here we show that by controlling the liquid cell surface chemistry and electron beam effects, the dynamics and self-assembly of metal-organic frameworks (MOFs) can be observed. Our results demonstrate that hybrid organic/inorganic beam sensitive materials can be analyzed with LCTEM and at least in the case of Zif-8 dynamics, the results correlate with observations from bulk growth or other standard synthetic conditions. We anticipate that direct, nanoscale imaging by LCTEM of MOF nucleation and growth mechanisms, may provide insight into controlled MOF crystal morphology, domain composition, and processes influencing defect formation.

  4. Graphite/isobutylene-isoprene rubber highly porous cryogels as new sorbents for oil spills and organic liquids.

    PubMed

    Hu, Yan; Liu, Xiaoyan; Zou, Junchen; Gu, Ting; Chai, Wenbo; Li, Hongbing

    2013-08-28

    The preparation, by a freeze-thaw method, of new graphite/isobutylene-isoprene rubber (IIR) sorbents for oil and organic liquid is described. Graphite was expected to improve the adsorption properties. The cryogels were prepared by solution crosslinking IIR rubber in the presence of graphite in benzene at various temperatures, using sulfur monochloride as the crosslinker, and characterized by SEM and contact angle measurements. The dried cryogels, with interconnected macropores were sponge-like soft materials, with excellent buoyancy and hydrophobicity. They also showed excellent sorption characteristics, with the best sample exhibiting maximum sorption capacities of 17.8 g g(-1) for crude oil, 21.6 g g(-1) for diesel oil, and 23.4 g g(-1) for lubricating oil, respectively. The samples also showed excellent sorption capability for organic liquids, absorbing up to around twenty times their own mass. After rapid and effective desorption, taking just 3-5 h, the cryogels were recovered. They could also be reused more than 30 times by simply centrifuging to remove the sorbed liquid. These characteristics mean that the cryogels prepared in this study are promising materials for removal of large-scale oil or toxic organic spills.

  5. A complementary organic inverter of porphyrazine thin films: low-voltage operation using ionic liquid gate dielectrics.

    PubMed

    Fujimoto, Takuya; Miyoshi, Yasuhito; Matsushita, Michio M; Awaga, Kunio

    2011-05-28

    We studied a complementary organic inverter consisting of a p-type semiconductor, metal-free phthalocyanine (H(2)Pc), and an n-type semiconductor, tetrakis(thiadiazole)porphyrazine (H(2)TTDPz), operated through the ionic-liquid gate dielectrics of N,N-diethyl-N-methyl(2-methoxyethyl)ammonium bis(trifluoromethylsulfonyl)imide (DEME-TFSI). This organic inverter exhibits high performance with a very low operation voltage below 1.0 V and a dynamic response up to 20 Hz.

  6. Partition coefficients of organic compounds between water and imidazolium-, pyridinium-, and phosphonium-based ionic liquids.

    PubMed

    Padró, Juan M; Pellegrino Vidal, Rocío B; Reta, Mario

    2014-12-01

    The partition coefficients, P IL/w, of several compounds, some of them of biological and pharmacological interest, between water and room-temperature ionic liquids based on the imidazolium, pyridinium, and phosphonium cations, namely 1-octyl-3-methylimidazolium hexafluorophosphate, N-octylpyridinium tetrafluorophosphate, trihexyl(tetradecyl)phosphonium chloride, trihexyl(tetradecyl)phosphonium bromide, trihexyl(tetradecyl)phosphonium bis(trifluoromethylsulfonyl)imide, and trihexyl(tetradecyl)phosphonium dicyanamide, were accurately measured. In this way, we extended our database of partition coefficients in room-temperature ionic liquids previously reported. We employed the solvation parameter model with different probe molecules (the training set) to elucidate the chemical interactions involved in the partition process and discussed the most relevant differences among the three types of ionic liquids. The multiparametric equations obtained with the aforementioned model were used to predict the partition coefficients for compounds (the test set) not present in the training set, most being of biological and pharmacological interest. An excellent agreement between calculated and experimental log P IL/w values was obtained. Thus, the obtained equations can be used to predict, a priori, the extraction efficiency for any compound using these ionic liquids as extraction solvents in liquid-liquid extractions.

  7. Experimental and numerical investigation of the effect of liquid temperature on the sonolytic degradation of some organic dyes in water.

    PubMed

    Merouani, Slimane; Hamdaoui, Oualid; Boutamine, Zineb; Rezgui, Yacine; Guemini, Miloud

    2016-01-01

    This paper presents a comprehensive experimental and numerical investigation of the effects of liquid temperature on the sonochemical degradation of three organic dyes, Rhodamine B (RhB), Acid orange 7 (AO7) and Malachite green (MG), largely used in the textile industry. The experiments have been carried out for an ultrasonic frequency of 300 kHz. The obtained experimental results were discussed using a new approach combining the results of single-bubble event and the number of active bubbles. The single-bubble event was predicted using a model that combines the bubble dynamics with chemical kinetics occurring inside a bubble during the strong collapse. The number of active bubbles was predicted using a method developed in our previous work. The experiments showed that the degradation rate of the three dyes increased significantly with increasing liquid temperature in the range 25-55°C. It was predicted that the main pathway of pollutants degradation is the attack by OH radicals. The simulations showed that there exists an optimum liquid temperature of about 35°C for the production of OH inside a bubble whereas the number of active bubbles increased sharply with the rise of the liquid temperature. It was predicted that the overall production rate of OH increased with increasing liquid temperature in the range 25-55°C. Finally, it was concluded that the effect of liquid temperature on the sonochemical degradation of the three dyes in aqueous phase was controlled by the number of active bubbles in the range 35-55°C and by both the number of bubbles and the single bubble yield in the range 25-35°C.

  8. An in situ benzoylation-dispersive liquid-liquid microextraction method based on solidification of floating organic droplets for determination of biogenic amines by liquid chromatography-ultraviolet analysis.

    PubMed

    Jia, Shaodong; Ryu, Yeonsuk; Kwon, Sung Won; Lee, Jeongmi

    2013-03-22

    A novel analytical method consisting of in situ derivatization combined with liquid phase microextraction followed by liquid chromatography-ultraviolet detection (LC-UV) was developed to determine the biogenic amines (BAs) of alcoholic beverages. Nine BAs (putrescine, cadaverine, 1,3-diaminopropane, tryptamine, phenylethylamine, spermidine, spermine, histamine, and tyramine) were derivatized in situ with benzoyl chloride, extracted by dispersive liquid-liquid microextraction based on solidification of floating organic droplets (DLLME-SFO), and then chromatographed by LC-UV. Factors influencing the derivatization and extraction efficiency were optimized, including the reaction buffer pH and concentration, amount of derivatization reagent, reaction time, types and volumes of extraction and dispersive solvents, and extraction time. Under the optimized conditions, the method was linear over 0.05-8.0μgmL(-1) with an r(2)≥0.992 and exhibited intra- and inter-day precision less than 8.8% and 11.5%, respectively. The limit of detection ranged between 0.005 and 0.01μgmL(-1). The developed method using a basic LC-UV system is sensitive, rapid, convenient, green, and cost-effective. Moreover, it is versatile and practical for the analysis of BAs, as demonstrated by the successful application in four different types of popular alcoholic beverages (white wine, red wine, rice wine, and beer). Copyright © 2013 Elsevier B.V. All rights reserved.

  9. Sensitive determination of methadone in human serum and urine by dispersive liquid-liquid microextraction based on the solidification of a floating organic droplet followed by HPLC-UV.

    PubMed

    Taheri, Salman; Jalali, Fahimeh; Fattahi, Nazir; Jalili, Ronak; Bahrami, Gholamreza

    2015-10-01

    Dispersive liquid-liquid microextraction based on solidification of floating organic droplet was developed for the extraction of methadone and determination by high-performance liquid chromatography with UV detection. In this method, no microsyringe or fiber is required to support the organic microdrop due to the usage of an organic solvent with a low density and appropriate melting point. Furthermore, the extractant droplet can be collected easily by solidifying it at low temperature. 1-Undecanol and methanol were chosen as extraction and disperser solvents, respectively. Parameters that influence extraction efficiency, i.e. volumes of extracting and dispersing solvents, pH, and salt effect, were optimized by using response surface methodology. Under optimal conditions, enrichment factor for methadone was 134 and 160 in serum and urine samples, respectively. The limit of detection was 3.34 ng/mmL in serum and 1.67 ng/mL in urine samples. Compared with the traditional dispersive liquid-liquid microextraction, the proposed method obtained lower limit of detection. Moreover, the solidification of floating organic solvent facilitated the phase transfer. And most importantly, it avoided using high-density and toxic solvents of traditional dispersive liquid-liquid microextraction method. The proposed method was successfully applied to the determination of methadone in serum and urine samples of an addicted individual under methadone therapy.

  10. Dispersive liquid-liquid microextraction combined with semi-automated in-syringe back extraction as a new approach for the sample preparation of ionizable organic compounds prior to liquid chromatography.

    PubMed

    Melwanki, Mahaveer B; Fuh, Ming-Ren

    2008-07-11

    Dispersive liquid-liquid microextraction (DLLME) followed by a newly designed semi-automated in-syringe back extraction technique has been developed as an extraction methodology for the extraction of polar organic compounds prior to liquid chromatography (LC) measurement. The method is based on the formation of tiny droplets of the extractant in the sample solution using water-immiscible organic solvent (extractant) dissolved in a water-miscible organic dispersive solvent. Extraction of the analytes from aqueous sample into the dispersed organic droplets took place. The extracting organic phase was separated by centrifuging and the sedimented phase was withdrawn into a syringe. Then in-syringe back extraction was utilized to extract the analytes into an aqueous solution prior to LC analysis. Clenbuterol (CB), a basic organic compound used as a model, was extracted from a basified aqueous sample using 25 microL tetrachloroethylene (TCE, extraction solvent) dissolved in 500 microL acetone (as a dispersive solvent). After separation of the organic extracting phase by centrifuging, CB enriched in TCE phase was back extracted into 10 microL of 1% aqueous formic acid (FA) within the syringe. Back extraction was facilitated by repeatedly moving the plunger back and forth within the barrel of syringe, assisted by a syringe pump. Due to the plunger movement, a thin organic film is formed on the inner layer of the syringe that comes in contact with the acidic aqueous phase. Here, CB, a basic analyte, will be protonated and back extracted into FA. Various parameters affecting the extraction efficiency, viz., choice of extraction and dispersive solvent, salt effect, speed of syringe pump, back extraction time period, effect of concentration of base and acid, were evaluated. Under optimum conditions, precision, linearity (correlation coefficient, r(2)=0.9966 over the concentration range of 10-1000 ng mL(-1) CB), detection limit (4.9 ng mL(-1)), enrichment factor (175), relative

  11. Direct extraction of genomic DNA from maize with aqueous ionic liquid buffer systems for applications in genetically modified organisms analysis.

    PubMed

    Gonzalez García, Eric; Ressmann, Anna K; Gaertner, Peter; Zirbs, Ronald; Mach, Robert L; Krska, Rudolf; Bica, Katharina; Brunner, Kurt

    2014-12-01

    To date, the extraction of genomic DNA is considered a bottleneck in the process of genetically modified organisms (GMOs) detection. Conventional DNA isolation methods are associated with long extraction times and multiple pipetting and centrifugation steps, which makes the entire procedure not only tedious and complicated but also prone to sample cross-contamination. In recent times, ionic liquids have emerged as innovative solvents for biomass processing, due to their outstanding properties for dissolution of biomass and biopolymers. In this study, a novel, easily applicable, and time-efficient method for the direct extraction of genomic DNA from biomass based on aqueous-ionic liquid solutions was developed. The straightforward protocol relies on extraction of maize in a 10 % solution of ionic liquids in aqueous phosphate buffer for 5 min at room temperature, followed by a denaturation step at 95 °C for 10 min and a simple filtration to remove residual biopolymers. A set of 22 ionic liquids was tested in a buffer system and 1-ethyl-3-methylimidazolium dimethylphosphate, as well as the environmentally benign choline formate, were identified as ideal candidates. With this strategy, the quality of the genomic DNA extracted was significantly improved and the extraction protocol was notably simplified compared with a well-established method.

  12. Nanostructural organization and anion effects on the temperature dependence of the optical Kerr effect spectra of ionic liquids.

    PubMed

    Xiao, Dong; Rajian, Justin Rajesh; Cady, Amanda; Li, Shengfu; Bartsch, Richard A; Quitevis, Edward L

    2007-05-10

    The intermolecular spectra of three imidazolium ionic liquids were studied as a function of temperature by the use of optical heterodyne-detected Raman-induced Kerr effect spectroscopy. The ionic liquids comprise the 1,3-pentylmethylimidazolium cation ([C(5)mim]+), and the anions, bromide (Br-), hexafluorophosphate (PF(6)-), and bis(trifluoromethanesulfonyl)imide (NTf(2)-). Whereas the optical Kerr effect (OKE) spectrum of [C(5)mim][NTf(2)] is temperature-dependent, the OKE spectra of [C(5)mim]Br and [C(5)mim][PF6] are temperature-independent. These results are surprising in light of the fact that the bulk densities of these room temperature ionic liquids (RTILs) are temperature-dependent. The temperature independence of the OKE spectra and the temperature dependence of the bulk density in [C(5)mim]Br and [C(5)mim][PF(6)] suggest that there are inhomogeneities in the densities of these liquids. The existence of density inhomogeneities is consistent with recent molecular dynamics simulations that show RTILs to be nanostructurally organized with nonpolar regions arising from clustering of the alkyl chains and ionic networks arising from charge ordering of the anions and imidazolium rings of the cations. Differences in the temperature dependences of the OKE spectra are rationalized on the basis of the degree of charge ordering in the polar regions of the RTILs.

  13. Dispersive liquid-liquid microextraction method based on solidification of floating organic droplet for the determination of thiamphenicol and florfenicol in environmental water samples.

    PubMed

    Peng, Guilong; He, Qiang; Al-Hamadani, Sulala M Z F; Zhou, Guangming; Liu, Mengzi; Zhu, Hui; Chen, Junhua

    2015-05-01

    Dispersive liquid-liquid microextraction with solidification of a floating organic droplet (DLLME-SFO) followed by high performance liquid chromatography-ultraviolet (HPLC-UV) detection was applied for the determination of thiamphenicol (TAP), florfenicol (FF) in water samples. 1-Undecanol was used as the extraction solvent which has lower density than water, low toxicity, and low melting point (19°C). A mixture of 800mL acetone (disperser solvent) and 80µL of 1-undecanol (extraction solvent) was injected into 20mL of aqueous solution. After 5min, 0.6g of NaCl was added and the sample vial was shaken. After 5min, the sample was centrifuged at 3500rpm for 3min, and then placed in an ice bath. When the extraction solvent floating on the aqueous solution had solidified, it was transferred into another conical vial where it was melted quickly at room temperature, and was diluted with methanol to 1mL, and analyzed by HPLC-UV detection. Parameters influencing the extraction efficiency were thoroughly examined and optimized. The extraction recoveries (ER) and the enrichment factors (EF) ranged from 67% to 72% and 223 to 241, respectively. The limits of detection (LODs) (S/N=3) were 0.33 and 0.56µgL(-1) for TAP and FF, respectively. Linear dynamic range (LDR) was in the range of 1.0-550µgL(-1) for TAP and 1.5-700µgL(-1) for FF, the relative standard deviations (RSDs) were in the range of 2.6-3.5% and the recoveries of spiked samples ranged from 94% to 106%.

  14. Multi-target determination of organic ultraviolet absorbents in organism tissues by ultrasonic assisted extraction and ultra-high performance liquid chromatography-tandem mass spectrometry.

    PubMed

    Peng, Xianzhi; Jin, Jiabin; Wang, Chunwei; Ou, Weihui; Tang, Caiming

    2015-03-06

    A sensitive and reliable method was developed for multi-target determination of 13 most widely used organic ultraviolet (UV) absorbents (including UV filters and UV stabilizers) in aquatic organism tissues. The organic UV absorbents were extracted using ultrasonic-assisted extraction, purified via gel permeation chromatography coupled with silica gel column chromatography, and determined by ultra-high performance liquid chromatography-tandem mass spectrometry. Recoveries of the UV absorbents from organism tissues mostly ranged from 70% to 120% from fish filet with satisfactory reproducibility. Method quantification limits were 0.003-1.0ngg(-1) dry weight (dw) except for 2-ethylhexyl 4-methoxycinnamate. This method has been applied to analysis of the UV absorbents in wild and farmed aquatic organisms collected from the Pearl River Estuary, South China. 2-Hydroxy-4-methoxybenzophenone and UV-P were frequently detected in both wild and farmed marine organisms at low ngg(-1)dw. 3-(4-Methylbenzylidene)camphor and most of the benzotriazole UV stabilizers were also frequently detected in maricultured fish. Octocrylene and 2-ethylhexyl 4-methoxycinnamate were not detected in any sample. This work lays basis for in-depth study about bioaccumulation and biomagnification of the UV absorbents in marine environment.

  15. Separation/preconcentration and determination of vanadium with dispersive liquid-liquid microextraction based on solidification of floating organic drop (DLLME-SFO) and electrothermal atomic absorption spectrometry.

    PubMed

    Asadollahi, Tahereh; Dadfarnia, Shayessteh; Shabani, Ali Mohammad Haji

    2010-06-30

    A novel dispersive liquid-liquid microextraction based on solidification of floating organic drop (DLLME-SFO) for separation/preconcentration of ultra trace amount of vanadium and its determination with the electrothermal atomic absorption spectrometry (ETAAS) was developed. The DLLME-SFO behavior of vanadium (V) using N-benzoyl-N-phenylhydroxylamine (BPHA) as complexing agent was systematically investigated. The factors influencing the complex formation and extraction by DLLME-SFO method were optimized. Under the optimized conditions: 100 microL, 200 microL and 25 mL of extraction solvent (1-undecanol), disperser solvent (acetone) and sample volume, respectively, an enrichment factor of 184, a detection limit (based on 3S(b)/m) of 7 ng L(-1) and a relative standard deviation of 4.6% (at 500 ng L(-1)) were obtained. The calibration graph using the preconcentration system for vanadium was linear from 20 to 1000 ng L(-1) with a correlation coefficient of 0.9996. The method was successfully applied for the determination of vanadium in water and parsley.

  16. Dispersive liquid-liquid microextraction method based on solidification of floating organic droplet for the determination of triazine herbicides in water and sugarcane samples.

    PubMed

    Sanagi, Mohd Marsin; Abbas, Hana Hassan; Ibrahim, Wan Aini Wan; Aboul-Enien, Hassan Y

    2012-07-15

    Dispersive liquid-liquid microextraction method based on solidification of floating organic droplet (DLLME-SFO) was developed for the analysis of triazines. As model compounds four selected triazine herbicides namely, simazine, atrazine, secbumeton and cyanazine were employed to estimate the extraction efficiency. The experimental conditions were comprehensively studied for the DLLME-SFO method. Under the use of 10 μL of 1-undecanol as extraction solvent, 100 μL of acetonitrile as disperser solvent and 5% (w/v) NaCl for 3 min the results demonstrated that the repeatability (RSD%) of the optimised DLLME-SFO method ranged from 0.03% to 5.1% and the linearity in the range of 0.01-100 ppb. Low limits of detection (0.037-0.008 ppb), and good enrichment factors (195-322) were obtained. The DLLME-SFO method applied in water and sugarcane samples showed excellent relative recoveries (95.7-116.9%) with RSDs <8.6% (n=3) for all samples.

  17. Indirect spectrophotometric determination of ultra trace amounts of selenium based on dispersive liquid-liquid microextraction-solidified floating organic drop.

    PubMed

    Haji Shabani, Ali Mohammad; Dadfarnia, Shayessteh; Nozohor, Mahnaz

    2013-12-01

    A novel dispersive liquid-liquid microextraction-solidified floating organic drop (DLLME-SFOD) method combined with fiber optic-linear array detection spectrophotometry has been developed for the indirect determination of selenium. The method is based on the oxidation of the I(-) to iodine by inorganic Se(IV). The produced I2 reacts with the excess of I(-) ions in acidic media to give triiodide ions. The I3(-) is then extracted into 1-undecanol by DLLME-SFOD upon the formation of an ion pair with cetyltrimethylammonium cation. The extracted ion pair is determined by measuring its absorption at 360 nm. The absorbance signal is proportional to the selenium concentration in the aqueous phase. Under optimum conditions, the method provided an enrichment factor of 250 with a detection limit of 16.0 μg L(-1) and a linear dynamic range of 40.0-1000.0 μg L(-1). The relative standard deviation was found to be 2.1% (n=7) at 100.0 μg L(-1) concentration level. The method was successfully applied to th e determination of selenium in water samples and selenium plus tablet. Copyright © 2013 Elsevier B.V. All rights reserved.

  18. Optimization of dispersive liquid-phase microextraction based on solidified floating organic drop combined with high-performance liquid chromatography for the analysis of glucocorticoid residues in food.

    PubMed

    Huang, Yuan; Zheng, Zhiqun; Huang, Liying; Yao, Hong; Wu, Xiao Shan; Li, Shaoguang; Lin, Dandan

    2017-05-10

    A rapid, simple, cost-effective dispersive liquid-phase microextraction based on solidified floating organic drop (SFOD-LPME) was developed in this study. Along with high-performance liquid chromatography, we used the developed approach to determine and enrich trace amounts of four glucocorticoids, namely, prednisone, betamethasone, dexamethasone, and cortisone acetate, in animal-derived food. We also investigated and optimized several important parameters that influenced the extraction efficiency of SFOD-LPME. These parameters include the extractant species, volumes of extraction and dispersant solvents, sodium chloride addition, sample pH, extraction time and temperature, and stirring rate. Under optimum experimental conditions, the calibration graph exhibited linearity over the range of 1.2-200.0ng/ml for the four analytes, with a reasonable linearity(r(2): 0.9990-0.9999). The enrichment factor was 142-276, and the detection limits was 0.39-0.46ng/ml (0.078-0.23μg/kg). This method was successfully applied to analyze actual food samples, and good spiked recoveries of over 81.5%-114.3% were obtained. Copyright © 2017. Published by Elsevier B.V.

  19. Dispersive liquid-liquid microextraction based on solidification of floating organic drop for preconcentration and determination of trace amounts of copper by flame atomic absorption spectrometry.

    PubMed

    Karadaş, Cennet; Kara, Derya

    2017-04-01

    A novel, simple, rapid, sensitive, inexpensive and environmentally friendly dispersive liquid-liquid microextraction method based on the solidification of a floating organic drop (DLLME-SFO) was developed for the determination of copper by flame atomic absorption spectrometry (FAAS). N-o-Vanillidine-2-amino-p-cresol was used as a chelating ligand and 1-undecanol was selected as an extraction solvent. The main parameters affecting the performance of DLLME-SFO, such as sample pH, volume of extraction solvent, extraction time, concentration of the chelating ligand, salt effect, centrifugation time and sample volume were investigated and optimized. The effect of interfering ions on the recovery of copper was also examined. Under the optimum conditions, the detection limit (3σ) was 0.93μgL(-1) for Cu using a sample volume of 20mL, yielding a preconcentration factor of 20. The proposed method was successfully applied to the determination of Cu in tap, river and seawater, rice flour and black tea samples as well as certified reference materials. Copyright © 2016. Published by Elsevier Ltd.

  20. Preconcentration of organochlorine pesticides in aqueous samples by dispersive liquid-liquid microextraction based on solidification of floating organic drop after SPE with multiwalled carbon nanotubes.

    PubMed

    Mirzaei, Mohammad; Rakh, Mojgan

    2014-01-01

    SPE joined with dispersive liquid-liquid microextraction based on solidification of floating organic drop (DLLME-SFO) as a novel technique combined with GC with electron-capture detection has been developed as a preconcentration technique for the determination of organochlorine pesticides (OCPs) in water samples. Aqueous samples were loaded onto multiwalled carbon nanotubes as sorbent. After the elution of the desired compounds from the sorbent by using acetone, the DLLME-SFO technique was performed on the obtained solution. Variables affecting the performance of both steps such as sample solution flow rate, breakthrough volume, type and volume of the elution, type and volume of extraction solvent and salt addition were studied and optimized. The new method provided an ultra enrichment factor (8280-28221) for nine OCPs. The calibration curves were linear in the range of 0.5-1000 ng/L, and the LODs ranged from 0.1-0.39 ng/L. The RSD, for 0.01 μg/L of OCPs, was in the range of 1.39-13.50% (n = 7). The recoveries of method in water samples were 70-113%. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Determination of boron in water samples by dispersive liquid-liquid microextraction based on the solidification of a floating organic drop coupled with a fluorimetric method.

    PubMed

    Peng, Guilong; He, Qiang; Li, Haifang; Mmereki, Daniel; Lu, Ying; Zheng, Yongzan; Zhong, Zhihui; Lin, Jin-Ming

    2016-04-07

    In this work, a new, rapid and reliable method for the determination of boron in water samples by dispersive liquid-liquid microextraction based on the solidification of a floating organic drop (DLLME-SFO) prior to fluorescence spectra analysis was developed. As a result of its complexation with boric acid, the method relies on the enhancement of the fluorescence (λex = 350 nm, λem = 373 nm) of chromotropic acid. The influences of DLLME-SFO parameters, including the extraction solvent type and its volume, pH, the disperser solvent type and its volume, and salt effects were investigated. Under the optimized conditions, the limit of detection was 0.11 ng L(-1), with a preconcentration factor of 86 times. The calibration curve was linear in the range of 0-40 nM. The proposed method has also been successfully applied to analyze real water samples and the relative recoveries of water samples ranged from 86.9 to 93.2%.

  2. Solid-Phase Extraction Followed by Dispersive Liquid-Liquid Microextraction Based on Solidification of Floating Organic Drop for the Determination of Parabens.

    PubMed

    Hashemi, Beshare; Shamsipur, Mojtaba; Fattahi, Nazir

    2015-09-01

    A dispersive liquid-liquid microextraction based on solidification of floating organic drop method combined with solid-phase extraction (500-mg C18 sorbent) was developed for preconcentration and determination of some parabens. The experimental parameters influencing the extraction efficiency such as the type of extraction and disperser solvents, as well as their volumes, breakthrough volume, flow rate and salt addition were studied and optimized. The optimum experimental conditions found included: sample volume, 100 mL; KCl concentration, 1% (w/v); extraction solvent (1-undecanol) volume, 20 µL and disperser solvent (acetone) volume, 250 µL. Under the optimum experimental conditions, calibration graphs were linear in the range of 1-200 µg L(-1) with limits of detection ranged from 0.3 to 1.7 µg L(-1). The relative standard deviations were in the range of 1.2-3.1% (n = 5). The enrichment factors and absolute recoveries of parabens in different matrices were 245-1886 and 9.0-69.8%, respectively. The method was applied to the simultaneous determination of parabens in different matrices. The relative recoveries from water, shampoo and mouth rinse samples, which have been spiked at different levels of parabens, were 87.83-112.25%, 82.80-108.40% and 90.10-97.60%, respectively. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  3. Indirect spectrophotometric determination of ultra trace amounts of selenium based on dispersive liquid-liquid microextraction-solidified floating organic drop

    NASA Astrophysics Data System (ADS)

    Haji Shabani, Ali Mohammad; Dadfarnia, Shayessteh; Nozohor, Mahnaz

    2013-12-01

    A novel dispersive liquid-liquid microextraction-solidified floating organic drop (DLLME-SFOD) method combined with fiber optic-linear array detection spectrophotometry has been developed for the indirect determination of selenium. The method is based on the oxidation of the I- to iodine by inorganic Se(IV). The produced I2 reacts with the excess of I- ions in acidic media to give triiodide ions. The I3- is then extracted into 1-undecanol by DLLME-SFOD upon the formation of an ion pair with cetyltrimethylammonium cation. The extracted ion pair is determined by measuring its absorption at 360 nm. The absorbance signal is proportional to the selenium concentration in the aqueous phase. Under optimum conditions, the method provided an enrichment factor of 250 with a detection limit of 16.0 μg L-1 and a linear dynamic range of 40.0-1000.0 μg L-1. The relative standard deviation was found to be 2.1% (n = 7) at 100.0 μg L-1 concentration level. The method was successfully applied to the determination of selenium in water samples and selenium plus tablet.

  4. Separation/preconcentration and determination of quercetin in food samples by dispersive liquid-liquid microextraction based on solidification of floating organic drop -flow injection spectrophotometry.

    PubMed

    Asadollahi, Tahereh; Dadfarnia, Shayessteh; Haji Shabani, Ali Mohammad; Amirkavei, Mooud

    2015-02-01

    A new dispersive liquid-liquid microextraction based on solidification of floating organic drop (DLLME-SFOD)-flow injection spectrophotometry (FI) method for the separation and preconcentration of trace amounts of quercetin was developed. 1-Undecanol and methanol was used as the extraction and disperser solvent, respectively. The factors influencing the extraction by DLLME-SFOD such as the volume of the extraction and disperser solvents, pH and concentration of salt were optimized. The optimal conditions were found to be; volume of the extraction solvent, 80 μL; the volume of the disperser solvent, 100 μL; and the pH of the sample, 3. The linear dynamic range and detection limit were 5.0 × 10(-8)-5.0 × 10(-7) mol L(-1) and 1 × 10(-8) mol L(-1), respectively. The relative standard deviation (R.S.D.) at 6.1 × 10(-8) mol L(-1) level of quercetin (n = 10) was found to be 2.8 %. The method was successfully applied to the determination of quercetin in the apple, grape, onion and tomato samples. Figureᅟ

  5. Enhanced low-temperature ionic conductivity via different Li(+) solvated clusters in organic solvent/ionic liquid mixed electrolytes.

    PubMed

    Aguilera, Luis; Scheers, Johan; Matic, Aleksandar

    2016-09-14

    We investigate Li(+) coordination in mixed electrolytes based on ionic liquids (ILs) and organic solvents and its relation with the macroscopic properties such as phase behaviour and ionic conductivity. Using Raman spectroscopy we determine the solvation shell around Li(+) in mixtures formed by the IL N-butyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide, the organic solvents ethylene carbonate and dimethyl carbonate (EC : DMC 1 : 1), and the salt LiTFSI. We find that the organic solvent molecules preferentially solvate Li(+) as long as there are enough of them. Our results are consistent with a model where Li(EC)3(DMC)1 and Li(EC)2(DMC)2 are the main complexes formed by the organic solvent molecules and where TFSI(-) mainly participates in Li(TFSI)2(-) clusters. As the amount of organic solvent is increased, the number of TFSI(-) around Li(+) rapidly decreases showing a higher affinity of the organic solvents to solvate Li(+). The changes in the local configurations are also reflected in the ionic conductivity and the phase behaviour. The formation of larger clusters leads to a decrease in the conductivity, whereas the presence of several different clusters at intermediate compositions effectively hinders crystallization at low temperatures. The result is an enhanced low-temperature ionic conductivity in comparison with the pure IL or organic solvent electrolytes.

  6. Facile preparation of organic-silica hybrid monolith for capillary hydrophilic liquid chromatography based on "thiol-ene" click chemistry.

    PubMed

    Chen, Ming-Luan; Zhang, Jun; Zhang, Zheng; Yuan, Bi-Feng; Yu, Qiong-Wei; Feng, Yu-Qi

    2013-04-05

    In this work, a one-step approach to facile preparation of organic-inorganic hybrid monoliths was successfully developed. After vinyl-end organic monomers and azobisisobutyronitrile (AIBN) were mixed with hydrolyzed tetramethoxysilane (TMOS) and 3-mercaptopropyltrimethoxysilane (MPTMS), the homogeneous mixture was introduced into a fused-silica capillary for simultaneous polycondensation and "thiol-ene" click reaction to form the organic-silica hybrid monoliths. By employing this strategy, two types of organic-silica hybrid monoliths with positively charged quaternary ammonium and amide groups were prepared, respectively. The functional groups were successfully introduced onto the monoliths during the sol-gel process with "thiol-ene" click reaction, which was demonstrated by ζ-potential assessment, energy dispersive X-ray spectroscopy (EDX), and Fourier transform infrared (FT-IR) spectroscopy. The porous structure of the prepared monolithic columns was examined by scanning electron microscopy (SEM), nitrogen adsorption-desorption measurement, and mercury intrusion porosimetry. These results indicate the prepared organic-silica hybrid monoliths possess homogeneous column bed, large specific surface area, good mechanical stability, and excellent permeability. The prepared monolithic columns were then applied for anion-exchange/hydrophilic interaction liquid chromatography. Different types of analytes, including benzoic acids, inorganic ions, nucleosides, and nucleotides, were well separated with high column efficiency around 80,000-130,000 plates/m. Taken together, we present a facile and universal strategy to prepare organic-silica hybrid monoliths with a variety of organic monomers using one-step approach.

  7. Variable toxicity of ionic liquid-forming chemicals to Lemna minor and the influence of dissolved organic matter.

    PubMed

    Larson, James H; Frost, Paul C; Lamberti, Gary A

    2008-03-01

    Ionic liquids (ILs) are nonvolatile organic salts that remain liquid over a wide range of temperatures. Ionic liquids are promoted as environmentally friendly alternatives to the volatile organic solvents that are currently in widespread industrial usage. Although ILs are unlikely to contribute to air pollution, their potential effects on aquatic ecosystems are largely unknown. Furthermore, information is lacking on how ILs will interact with common features of aquatic environments, such as dissolved organic matter (DOM). We assessed the effect of five IL-forming chemicals on the growth of duckweed, Lemna minor, a common aquatic vascular plant. In general, 1-alkyl-3-methylimidazolium chemicals with longer alkyl chains were more toxic to L. minor than those with short alkyl chain lengths. The concentration that produced a 50% reduction (the EC50) in root growth was 8.56 ppm when a butyl chain was present but was 0.25 ppm (i.e., much more toxic) when an octyl chain was substituted. Butyl-substituted 3-methylpyridinium (root growth EC50 of 7.49 ppm) and 3-methylimidazolium cations had similar toxicity, whereas a tetrabutyl ammonium cation was considerably less toxic (root growth EC50 of 32.71 ppm). When we tested whether DOM reduced the toxicity of these cations, we saw no effect of a low-molecular-weight organic acid or commercial humic matter. In contrast, natural DOM reduced the toxicity of imidazolium, but only at low concentrations. Design and use of ILs and other new chemicals should incorporate not only standard toxicity tests but also information on how such chemicals will interact with other components of aquatic ecosystems.

  8. CTEPP STANDARD OPERATING PROCEDURE FOR EXTRACTING AND PREPARING LIQUID FOOD SAMPLES FOR ANALYSIS OF PERSISTENT ORGANIC POLLUTANTS (SOP-5.19)

    EPA Science Inventory

    This SOP describes the procedures for homogenizing, extracting, and concentrating liquid food samples for neutral persistent organic pollutants such as organochlorine compounds, organophosphate compounds, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and phenols.

  9. CTEPP STANDARD OPERATING PROCEDURE FOR EXTRACTING AND PREPARING LIQUID FOOD SAMPLES FOR ANALYSIS OF PERSISTENT ORGANIC POLLUTANTS (SOP-5.19)

    EPA Science Inventory

    This SOP describes the procedures for homogenizing, extracting, and concentrating liquid food samples for neutral persistent organic pollutants such as organochlorine compounds, organophosphate compounds, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and phenols.

  10. Ionic liquid-assisted liquid-phase microextraction based on the solidification of floating organic droplets combined with high performance liquid chromatography for the determination of benzoylurea insecticide in fruit juice.

    PubMed

    Yang, Miyi; Zhang, Panjie; Hu, Lu; Lu, Runhua; Zhou, Wenfeng; Zhang, Sanbing; Gao, Haixiang

    2014-09-19

    A green, simple, and efficient method, ionic liquid-assisted liquid-liquid microextraction based on the solidification of floating organic droplets (ILSFOD-LLME) collected via a bell-shaped collection device (BSCD) coupled to high performance liquid chromatography with a variable-wavelength detector, was developed for the preconcentration and analysis of seven benzoylurea insecticides (BUs) in fruit juice. In the proposed method, the low-density solvent 1-dodecanol and the ionic liquid trihexyl(tetradecyl)phosphonium hexafluorophosphate ([P14, 6, 6, 6]PF6) were used as extractant. The extraction solvent droplet was easily collected and separated by the BSCD without centrifugation. The experimental parameters were optimized by the one-factor-at-a-time approach and were followed using an orthogonal array design. The results indicated the different effects of each parameter for extraction efficiency. Under the optimal conditions in the water model, the limits of detection for the analytes varied from 0.03 to 0.28μgL(-1). The enrichment factors ranged from 160 to 246. Linearities were achieved for hexaflumuron and flufenoxuron in the range of 0.5-500μgL(-1), for triflumuron, lufenuron and diafenthiuron in the range of 1-500μgL(-1), and for diflubenzuron and chlorfluazuron in the range of 5-500μgL(-1); the correlation coefficients for the BUs ranged from 0.9960 to 0.9990 with recoveries of 75.6-113.9%. Finally, the developed technique was successfully applied to real fruit juice with acceptable results. The relative standard deviations (RSDs) of the seven BUs at two spiked levels (50 and 200μgL(-1)) varied between 0.1% and 7.3%. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. A preliminary assessment of the feasibility of deriving liquid and gaseous fuels from grown and waste organics

    NASA Technical Reports Server (NTRS)

    Graham, R. W.; Reynolds, T. W.; Hsu, Y. Y.

    1976-01-01

    The anticipated depletion of our resources of natural gas and petroleum in a few decades has caused a search for renewable sources of fuel. Among the possibilities is the chemical conversion of waste and grown organic matter into gaseous or liquid fuels. The overall feasibility of such a system is considered from the technical, economic, and social viewpoints. Although there are a number of difficult problems to overcome, this preliminary study indicates that this option could provide between 4 and 10 percent of the U.S. energy needs. Estimated costs of fuels derived from grown organic material are appreciably higher than today's market price for fossil fuel. The cost of fuel derived from waste organics is competitive with fossil fuel prices. Economic and social reasons will prohibit the allocation of good food producing land to fuel crop production.

  12. Use of on-site high performance liquid chromatography to evaluate the magnitude and extent of organic contaminants in aquifers

    USGS Publications Warehouse

    Goerlitz, D.F.; Franks, B.J.

    1989-01-01

    Appraisal of ground water contaminated by organic substances raises problems of difficult sample collection and timely chemical analysis. High-performance liquid chromatography was evaluated for on-site determination of specific organic contaminants in ground water samples and was used at three study sites. Organic solutes were determined directly in water samples, with little or no preparation, and usually in less than an hour after collection. This information improved sampling efficiency and was useful in screening for subsequent laboratory analysis. On two occasions, on-site analysis revealed that samples were undergoing rapid change, with major solutes being upgraded and alteration products being formed. In addition to sample stability, this technique proved valuable for monitoring other sampling factors such as compositional changes with respect to pumping, filtration, and cross contamination. -Authors

  13. Dispersive liquid-liquid microextraction method based on solidification of floating organic drop combined with gas chromatography with electron-capture or mass spectrometry detection.

    PubMed

    Leong, Mei-I; Huang, Shang-Da

    2008-11-21

    A simple dispersive liquid-liquid microextraction (DLLME) method based on solidification of a floating organic drop (DLLME-SFO) technique combined with gas chromatography/electron-capture detection (GC/ECD) or gas chromatography/mass spectrometry (GC/MS) has been developed. The proposed method is simple, low in cost, and of high precision. It overcomes the most important problem in DLLME, the high-toxic solvent used. Halogenated organic compounds (HOCs) in water samples were determined as the model compounds. The parameters optimized for the DLLME-SFO technique were as follows: A mixture of 0.5 mL acetone, containing 10 microL 2-dodecanol (2-DD-OH), was rapidly injected by syringe into the 5 mL water sample. After centrifugation, the fine 2-DD-OH droplets (8+/-0.5 microL) were floated at the top of the screwcap test tube. The test tube was then cooled in an ice bath. After 5 min the 2-DD-OH solvent had solidified and was then transferred into a conical vial; it melted quickly at room temperature and 3 microL (for GC/ECD) or 2 microL (for GC/MS) of it was injected into a gas chromatograph for analysis. The limit of detection (LOD) for this technique was 0.005-0.05microgL(-1) for GC/ECD and was 0.005-0.047 microgL(-1) for GC/MS, respectively. The linear range of the calibration curve of DLLME-SFO was from 0.01 to 500 microgL(-1) with a coefficient of estimation (r2)>0.996 for GC/ECD and was from 0.02 to 500 microgL(-1) with a coefficient of estimation (r2)>0.996 for GC/MS.

  14. Vortex-assisted surfactant-enhanced-emulsification liquid-liquid microextraction with solidification of floating organic droplet combined with HPLC for the determination of neonicotinoid pesticides.

    PubMed

    Vichapong, Jitlada; Burakham, Rodjana; Srijaranai, Supalax

    2013-12-15

    A microextraction procedure based on vortex-assisted surfactant-enhanced-emulsification liquid-liquid microextraction with solidification of floating organic droplet (VSLLME-SFO) for preconcentration of neonicotinoid pesticides, including acetamiprid, clotianidin, nitenpyram, imidacloprid, and thiamethoxam, has been developed. In VSLLME-SFO process, the addition of surfactant (as an emulsifier), could be enhance the mass-transfer from the aqueous solution into the extraction solvent. The extraction solvent could be dispersed into the aqueous by vortex process. Other experimental parameters affected the extraction efficiency, including the kind and concentration of salt, concentration and volume of HCl, kind and concentration of surfactant and its volume, kind and volume of extraction solvent, vortex time and the centrifugation extraction time, were also optimized. The optimum extraction conditions of VSLLME-SFO were 10.00 mL of sample, 0.3% (w/v) Na2SO4, 50 µL of 0.050 mol L(-1) SDS, 1.0 mol L(-1) HCl (400 µL), 150 µL of octanol, vortex time 1 min and centrifugation time 10 min. The sediment phase was analyzed by subjecting it to HPLC using a mobile phase of 25% acetonitrile in water, at a flow rate of 1.0 mL min(-1), and photodiode array detection at 254 nm. Under the optimum extraction conditions, high enrichment factors (20-100 fold) and low limit of detection (0.1-0.5 μg L(-1)) could be obtained. This method provided high sensitivity, low toxic organic solvents used, and simplicity of the extraction processes. The proposed method was successfully applied in the analysis of neonicotinoids in fruit juice and water samples.

  15. A comparative study of room temperature ionic liquids and their organic solvent mixtures near charged electrodes

    NASA Astrophysics Data System (ADS)

    Vatamanu, Jenel; Vatamanu, Mihaela; Borodin, Oleg; Bedrov, Dmitry

    2016-11-01

    The structural properties of electrolytes consisting of solutions of ionic liquids in a polar solvent at charged electrode surfaces are investigated using classical atomistic simulations. The studied electrolytes consisted of tetraethylammonium tetrafluoroborate (NEt4-BF4), 1-ethyl-3-methylimidazolium tetrafluoroborate (c2mim-BF4) and 1-octyl-3-methylimidazolium tetrafluoroborate (c8mim-BF4) salts dissolved in acetonitrile solvent. We discuss the influence of electrolyte concentration, chemical structure of the ionic salt, temperature, conducting versus semiconducting nature of the electrode, electrode geometry and surface roughness on the electric double layer structure and capacitance and compare these properties with those obtained for pure room temperature ionic liquids. We show that electrolytes consisting of solutions of ions can behave quite differently from pure ionic liquid electrolytes.

  16. Ionic liquids as transesterification catalysts: applications for the synthesis of linear and cyclic organic carbonates.

    PubMed

    Selva, Maurizio; Perosa, Alvise; Guidi, Sandro; Cattelan, Lisa

    2016-01-01

    The use of ionic liquids (ILs) as organocatalysts is reviewed for transesterification reactions, specifically for the conversion of nontoxic compounds such as dialkyl carbonates to both linear mono-transesterification products or alkylene carbonates. An introductory survey compares pros and cons of classic catalysts based on both acidic and basic systems, to ionic liquids. Then, innovative green syntheses of task-specific ILs and their representative applications are introduced to detail the efficiency and highly selective outcome of ILs-catalyzed transesterification reactions. A mechanistic hypothesis is discussed by the concept of cooperative catalysis based on the dual (electrophilic/nucleophilic) activation of reactants.

  17. Ionic liquids as transesterification catalysts: applications for the synthesis of linear and cyclic organic carbonates

    PubMed Central

    Perosa, Alvise; Guidi, Sandro; Cattelan, Lisa

    2016-01-01

    Summary The use of ionic liquids (ILs) as organocatalysts is reviewed for transesterification reactions, specifically for the conversion of nontoxic compounds such as dialkyl carbonates to both linear mono-transesterification products or alkylene carbonates. An introductory survey compares pros and cons of classic catalysts based on both acidic and basic systems, to ionic liquids. Then, innovative green syntheses of task-specific ILs and their representative applications are introduced to detail the efficiency and highly selective outcome of ILs-catalyzed transesterification reactions. A mechanistic hypothesis is discussed by the concept of cooperative catalysis based on the dual (electrophilic/nucleophilic) activation of reactants. PMID:27829898

  18. The influence of interfacial properties on the two-phase liquid flow of organic contaminants in groundwater. Final report, July 1, 1989--June 30, 1992

    SciTech Connect

    Demond, A.H.; Desai, F.N.; Hayes, K.F.

    1992-12-31

    DOE`s waste sites are contaminated with a variety of organic liquids. Because of their low solubility in water, organic liquids such as these will persist as separate liquid phases and be transported as such in the subsurface. Thus, an improved understanding of the factors influencing the movement of a separate organic liquid phase in the subsurface is important to DOE`s efforts to control groundwater contamination. Wettability is sometimes cited as the most important factor influencing two-phase flow in porous media. The wetting phase migrates preferentially through the smaller pores, whereas the nonwetting phase is concentrated in the larger pores. Typically, aquifers are thought of as strongly water-wet, implying that the organic liquid preferentially occupies the larger pores. But in fact, that state depends on the properties of the three interfaces of the system: between the organic liquid and water, water and the solid, and the organic liquid and the solid. Characteristics of the system which affect the interfacial properties also impact the wettability, such as the nature of the aquifer solids` surfaces, the composition of the goundwater and the properties of the organic contaminant. The alteration of wettability at DOE waste sites may be dominated by the presence of co-contaminants such as organic acids and bases which behave as surface-active agents or surfactants. Because of their physicochemical nature, surfactants will sorb preferentially at the interfaces of the system, thereby impacting the wettability and the distribution of the liquids in the porous medium. The over-all objective of this research was to determine how changes in interfacial properties affect two-phase flow. Specifically, the objective was to examine the effect of surfactant sorption on capillary pressure relationships by correlating measurements of sorption, zeta potential, interfacial tension and contact angle, with changes in the capillary pressure-saturation relationships.

  19. Determination of fungicides in fruit juice by ultrasound-assisted dispersive liquid-liquid microextraction based on solidification of floating organic solvent droplets followed by high performance liquid chromatography.

    PubMed

    Fan, Run-Zhen; Liu, Congyun; Jiang, Wenqing; Wang, Xiaonan; Liu, Fengmao

    2014-01-01

    Ultrasound-assisted dispersive liquid-liquid microextraction (UA-DLLME) based on solidification of the floating organic solvent droplets (SFO) combined with HPLC was used for determination of five fungicides in fruit juice samples. 1-Dodecanol, which has a low density and low toxicity, was used as the extraction solvent in UA-DLLME. The solidification of floating organic droplets facilitates the transfer of analytes from the aqueous phase to the organic phase. This method was easy, quick, inexpensive, precise, and linear over a wide range. Under the optimized conditions, the enrichment factors for a 5 mL fruit juice sample were 25 to 56, and the LODs for the five fungicides ranged from 5 to 50 microg/L. The average recoveries ranged from 71.8 to 118.2% with RSDs of 0.9 to 13.9%. Application of the DLLME-SFO technique allows successful separation and preconcentration of the fungicides at a low concentration level in fruit juice samples.

  20. Production of 15N-Labelled Liquid Organic Fertilisers Based on Manure and Crop Residue for Use in Fertigation Studies

    PubMed Central

    Martínez-Alcántara, Belén; Martínez-Cuenca, Mary-Rus; Fernández, Carlos; Legaz, Francisco; Quiñones, Ana

    2016-01-01

    Large quantities of crop residue and animal manure from agricultural and livestock activities are annually produced worldwide. With proper management, these residues are potentially valuable sources of plant nutrients, mainly N. Recycling such subproducts in sustainably-based agricultural systems can minimise the use of mineral fertilisers, and hence reduce the potential risk of surface and groundwater pollution. Therefore, the purpose of this study was to obtain (small scale) two liquid labelled-organic fertilisers, an animal- and a vegetal-based organic (AO and VO, respectively) fertiliser, to be used as organic N sources in subsequent fertigation studies. Forage maize (Zea mays L.) grown under 15N-labelled fertiliser supply was used as raw material for VO fertiliser production, and also as 15N-labelled sheep feed to obtain 15N-labelled manure. The labelled faeces fraction was used as raw material for the AO fertiliser. The VO fertiliser was obtained after an acidic and an enzyme-driven hydrolysis. The AO fertiliser was obtained after acidic hydrolysis. The VO liquid fertiliser presented an N concentration of 330 mg·L-1, 85% of total N was organic, while ammonium and nitrate N accounted for 55% and 45% of the mineral nitrogen fraction, respectively. This fertiliser also exhibited high K, Ca and S concentrations and notable values for the remaining macro- and micronutrients. The AO liquid fertiliser had a similar total N concentration (496 mg·L-1, 82% of total N in an organic form) to that of VO, but its mineral N fraction significantly differed, which came in a predominantly (95%) ammonia form. It also had a high content of N, P, K and other macronutrients, and sufficient Fe, Zn, Mn, Cu and B levels, which suggests its suitability as a potential fertiliser. The percentage of 15N enrichment in both VO and AO liquid fertilisers exceeded 2% 15N atom excess, which enabled their use in subsequent assays run to assess nitrogen uptake efficiency. PMID:26982183

  1. Liquid-phase and vapor-phase dehydration of organic/water solutions

    DOEpatents

    Huang, Yu; Ly, Jennifer; Aldajani, Tiem; Baker, Richard W.

    2011-08-23

    Processes for dehydrating an organic/water solution by pervaporation or vapor separation using fluorinated membranes. The processes are particularly useful for treating mixtures containing light organic components, such as ethanol, isopropanol or acetic acid.

  2. Application of Light Reflection Visualization for Measuring Organic-Liquid Saturation for Two-Phase Systems in Two-Dimensional Flow Cells

    PubMed Central

    DiFilippo, Erica L.; Brusseau, Mark L.

    2011-01-01

    Abstract A simple, noninvasive imaging technique was used to obtain in situ measurements of organic-liquid saturation in a two-phase system under dynamic conditions. Efficacy of the light reflection visualization (LRV) imaging method was tested through comparison of measured and known volumes of organic liquid for experiments conducted with a two-dimensional flow cell. Two sets of experiments were conducted, with source-zone configurations representing two archetypical residual-and-pool architectures. LRV measurements were collected during the injection of organic liquid and during a dissolution phase induced by water flushing. There was a strong correlation between measured and known organic-liquid volumes, with the LRV-measured values generally somewhat lower than the known volumes. Errors were greater for the system wherein organic liquid was present in multiple zones comprised of porous media of different permeabilities, and for conditions of multiphase flow. This method proved effective at determining organic-liquid distribution in a two-phase system using minimal specialized equipment. PMID:26457050

  3. Application of Light Reflection Visualization for Measuring Organic-Liquid Saturation for Two-Phase Systems in Two-Dimensional Flow Cells.

    PubMed

    DiFilippo, Erica L; Brusseau, Mark L

    2011-11-01

    A simple, noninvasive imaging technique was used to obtain in situ measurements of organic-liquid saturation in a two-phase system under dynamic conditions. Efficacy of the light reflection visualization (LRV) imaging method was tested through comparison of measured and known volumes of organic liquid for experiments conducted with a two-dimensional flow cell. Two sets of experiments were conducted, with source-zone configurations representing two archetypical residual-and-pool architectures. LRV measurements were collected during the injection of organic liquid and during a dissolution phase induced by water flushing. There was a strong correlation between measured and known organic-liquid volumes, with the LRV-measured values generally somewhat lower than the known volumes. Errors were greater for the system wherein organic liquid was present in multiple zones comprised of porous media of different permeabilities, and for conditions of multiphase flow. This method proved effective at determining organic-liquid distribution in a two-phase system using minimal specialized equipment.

  4. On the Implications of aerosol liquid water and phase separation for modeled organic aerosol mass

    EPA Science Inventory

    Current chemical transport models assume that organic aerosol (OA)-forming compounds partition mostly to a water-poor, organic-rich phase in accordance with their vapor pressures. However, in the southeast United States, a significant fraction of ambient organic compounds are wat...

  5. On the Implications of aerosol liquid water and phase separation for modeled organic aerosol mass

    EPA Science Inventory

    Current chemical transport models assume that organic aerosol (OA)-forming compounds partition mostly to a water-poor, organic-rich phase in accordance with their vapor pressures. However, in the southeast United States, a significant fraction of ambient organic compounds are wat...

  6. Displacement-dispersive liquid-liquid microextraction based on solidification of floating organic drop of trace amounts of palladium in water and road dust samples prior to graphite furnace atomic absorption spectrometry determination.

    PubMed

    Ghanbarian, Maryam; Afzali, Daryoush; Mostafavi, Ali; Fathirad, Fariba

    2013-01-01

    A new displacement-dispersive liquid-liquid microextraction method based on the solidification of floating organic drop was developed for separation and preconcentration of Pd(ll) in road dust and aqueous samples. This method involves two steps of dispersive liquid-liquid microextraction based on solidification. In Step 1, Cu ions react with diethyldithiocarbamate (DDTC) to form Cu-DDTC complex, which is extracted by dispersive liquid-liquid microextraction based on a solidification procedure using 1-undecanol (extraction solvent) and ethanol (dispersive solvent). In Step 2, the extracted complex is first dispersed using ethanol in a sample solution containing Pd ions, then a dispersive liquid-liquid microextraction based on a solidification procedure is performed creating an organic drop. In this step, Pd(ll) replaces Cu(ll) from the pre-extracted Cu-DDTC complex and goes into the extraction solvent phase. Finally, the Pd(ll)-containing drop is introduced into a graphite furnace using a microsyringe, and Pd(ll) is determined using atomic absorption spectrometry. Several factors that influence the extraction efficiency of Pd and its subsequent determination, such as extraction and dispersive solvent type and volume, pH of sample solution, centrifugation time, and concentration of DDTC, are optimized.

  7. Influence of process parameters to composite interface organization and performance of liquid/solid bimetal

    NASA Astrophysics Data System (ADS)

    Rong, S. F.; Zhu, Y. C.; Wu, Y. H.; Yang, P. H.; Duan, X. L.; Zhou, H. T.

    2015-12-01

    The liquid-solid composite technique was used to prepare the high carbon high chromium steel (HCHCS) and low alloy steel (LCS) bimetal composite materials by means of insert casting method. The influence of some process parameters such as liquid-solid ratio, preheat temperature, pouring temperature on the interface microstructure and mechanical properties were studied. Interface microstructure and element distribution were analyzed. The results show that the interface microstructure becomes better, and bonding area becomes thicker with the increase of the volume of liquid to solid ratio, preheating temperature and pouring temperature. When the liquid-solid ratio is 8:1, the preheating temperature is 300 °C and the pouring temperature is 1565 °C, a good metallurgical bonding area without any hole can be obtained with the interface combination of diffusion and fusion. The composite interface structure was composed of a core material diffusion layer, a cooling solidification layer, a direction growth layer and some cell particles. The elements of C, Cr and Mn diffuse from the HCHCS side to the alloy steel side. The microhardness increased in the gradient from the LCS side to the HCHCS. The microhardness of the interface is significantly higher than that of LCS.

  8. Fluoroponytailed crown ethers and quaternary ammonium salts as solid-liquid phase transfer catalysts in organic synthesis.

    PubMed

    Pozzi, Gianluca; Fish, Richard H

    2012-01-01

    Fluorous derivatives of dibenzo-18-crown-6 ether were prepared, and then successfully applied in representative solid-liquid phase transfer catalysis reactions, which were performed in standard organic solvents, such as chlorobenzene and toluene, as well as in fluorous solvents, such as perfluoro-1,3-dimethylcyclohexane. It was clearly shown that properly designed fluoroponytailed crown ethers could promote the disintegration of the crystal lattice of alkali salts, and transfer anions from the solid surface into an apolar, non-coordinating perfluorocarbon phase, for phase transfer catalysis reactions in organic synthesis. Furthermore, 3,5-bis(perfluorooctyl)benzyl bromide and triethylamine were reacted under mild conditions to provide an analogue of the versatile phase transfer catalyst, benzyltriethylammonium chloride, containing two fluoroponytails. This fluoroponytailed quaternary ammonium salt was also successfully employed as a catalyst in a variety of organic reactions conducted under solid-liquid phase transfer catalysis conditions, without a perfluorocarbon phase. Thus, being both hydrophobic and lipophobic, fluorous crown ethers and ammonium salts, could be rapidly recovered in quantitative yields, and reused without loss of activity, over several reaction cycles.

  9. [Determination of sugars, organic acids and alcohols in microbial consortium fermentation broth from cellulose using high performance liquid chromatography].

    PubMed

    Jiang, Yan; Fan, Guifang; Du, Ran; Li, Peipei; Jiang, Li

    2015-08-01

    A high performance liquid chromatographic method was established for the determination of metabolites (sugars, organic acids and alcohols) in microbial consortium fermentation broth from cellulose. Sulfate was first added in the samples to precipitate calcium ions in microbial consortium culture medium and lower the pH of the solution to avoid the dissociation of organic acids, then the filtrates were effectively separated using high performance liquid chromatography. Cellobiose, glucose, ethanol, butanol, glycerol, acetic acid and butyric acid were quantitatively analyzed. The detection limits were in the range of 0.10-2.00 mg/L. The linear correlation coefficients were greater than 0.999 6 in the range of 0.020 to 1.000 g/L. The recoveries were in the range of 85.41%-115.60% with the relative standard deviations of 0.22% -4.62% (n = 6). This method is accurate for the quantitative analysis of the alcohols, organic acids and saccharides in microbial consortium fermentation broth from cellulose.

  10. Simultaneous optimization of variables influencing selectivity and elution strength in micellar liquid chromatography. Effect of organic modifier and micelle concentration.

    PubMed

    Strasters, J K; Breyer, E D; Rodgers, A H; Khaledi, M G

    1990-07-06

    Previously, the simultaneous enhancement of separation selectivity with elution strength was reported in micellar liquid chromatography (MLC) using the hybrid eluents of water-organic solvent-micelles. The practical implication of this phenomenon is that better separations can be achieved in shorter analysis times by using the hybrid eluents. Since both micelle concentration and volume fraction of organic modifier influence selectivity and solvent strength, only an investigation of the effects of a simultaneous variation of these parameters will disclose the full separation capability of the method, i.e. the commonly used sequential solvent optimization approach of adjusting the solvent strength first and then improving selectivity in reversed-phase liquid chromatography is inefficient for the case of MLC with the hybrid eluents. This is illustrated in this paper with two examples: the optimization of the selectivity in the separation of a mixture of phenols and the optimization of a resolution-based criterion determined for the separation of a number of amino acids and small peptides. The large number of variables involved in the separation process in MLC necessitates a structured approach in the development of practical applications of this technique. A regular change in retention behavior is observed with the variation of the surfactant concentration and the concentration of organic modifier, which enables a successful prediction of retention times. Consequently interpretive optimization strategies such as the interative regression method are applicable.

  11. Effect of organic solvents on Li+ ion solvation and transport in ionic liquid electrolytes: a molecular dynamics simulation study.

    PubMed

    Li, Zhe; Borodin, Oleg; Smith, Grant D; Bedrov, Dmitry

    2015-02-19

    Molecular dynamics simulations of N-methyl-N-propylpyrrolidinium (pyr13) bis(trifluoromethanesulfonyl)imide (Ntf2) ionic liquid [pyr13][Ntf2] doped with [Li][Ntf2] salt and mixed with acetonitrile (AN) and ethylene carbonate (EC) organic solvents were conducted using polarizable force field. Structural and transport properties of ionic liquid electrolytes (ILEs) with 20 and 40 mol % of organic solvents have been investigated and compared to properties of neat ILEs. Addition of AN and EC solvents to ILEs resulted in the partial displacement of the Ntf2 anions from the Li(+) first coordination shell by EC and AN and shifting the Li-Ntf2 coordination from bidentate to monodentate. The presence of organic solvents in ILE has increased the ion mobility, with the largest effect observed for the Li(+) cation. The Li(+) conductivity has doubled with addition of 40 mol % of AN. The Li(+)-N(Ntf2) residence times were dramatically reduced with addition of solvents, indicating an increasing contribution from structural diffusion of the Li(+) cations.

  12. Organic-resistant screen-printed graphitic electrodes: Application to on-site monitoring of liquid fuels.

    PubMed

    Almeida, Eduardo S; Silva, Luiz A J; Sousa, Raquel M F; Richter, Eduardo M; Foster, Christopher W; Banks, Craig E; Munoz, Rodrigo A A

    2016-08-31

    This work presents the potential application of organic-resistant screen-printed graphitic electrodes (SPGEs) for fuel analysis. The required analysis of the antioxidant 2,6-di-tert-butylphenol (2,6-DTBP) in biodiesel and jet fuel is demonstrated as a proof-of-concept. The screen-printing of graphite, Ag/AgCl and insulator inks on a polyester substrate (250 μm thickness) resulted in SPGEs highly compatible with liquid fuels. SPGEs were placed on a batch-injection analysis (BIA) cell, which was filled with a hydroethanolic solution containing 99% v/v ethanol and 0.1 mol L(-1) HClO4 (electrolyte). An electronic micropipette was connected to the cell to perform injections (100 μL) of sample or standard solutions. Over 200 injections can be injected continuously without replacing electrolyte and SPGE strip. Amperometric detection (+1.1 V vs. Ag/AgCl) of 2,6-DTBP provided fast (around 8 s) and precise (RSD = 0.7%, n = 12) determinations using an external calibration curve. The method was applied for the analysis of biodiesel and aviation jet fuel samples and comparable results with liquid and gas chromatographic analyses, typically required for biodiesel and jet fuel samples, were obtained. Hence, these SPGE strips are completely compatible with organic samples and their combination with the BIA cell shows great promise for routine and portable analysis of fuels and other organic liquid samples without requiring sophisticated sample treatments.

  13. Relationship study of partition coefficients between ionic liquid and headspace for organic solvents by HS-GC.

    PubMed

    Ni, Meiping; Sun, Ting; Zhang, Lin; Liu, Yan; Xu, Meng; Jiang, Ye

    2014-01-15

    A general study was carried out to investigate the relationship between analytes (organic solvents) and matrix medium (ionic liquids, ILs) by headspace gas chromatography (HS-GC) in order to provide a guidance to choose a suitable matrix medium during the process of experiment. Thirteen ILs contained different cations or anions and two kinds of organic solvents (alkylogens and aprotic solvents which involved ability of pro-proton) performed different interactions with ILs were chosen in this study. The concentrations of analytes in headspace were determined by HS-GC and then logK (the logarithm of concentration radio between matrix medium and headspace) was calculated respectively. Factors which affect logK, such as logPO/W (the logarithm of the octanol/water partition coefficient for a solvent) for different cations (including parent nucleus and alkyl chains) and anions of ILs, were investigated. The results indicated that the longer alkyl chains, the lower polarity of parent nucleus and the higher polarity of anions performed the higher headspace efficiency for alkylogens. Meanwhile, the shorter alkyl chains and the lower polarity of parent nucleus make the higher headspace efficiency for aprotic solvents which involved ability of pro-proton. For both kinds of organic solvents, anions of ILs performed little influences to headspace efficiency. The relationship between ILs and organic solvents was primarily investigated and a helpful guidance was provided for the application of ILs as matrix medium to analyze solvents by HS-GC. The model was successfully used to determine the organic residual solvents in ketoconanzale to choose a suitable ionic liquid during the process of HS-GC.

  14. Quantum chemical approach for condensed-phase thermochemistry (II): Applications to formation and combustion reactions of liquid organic molecules

    NASA Astrophysics Data System (ADS)

    Ishikawa, Atsushi; Nakai, Hiromi

    2015-03-01

    The harmonic solvation model (HSM), which was recently developed for evaluating condensed-phase thermodynamics by quantum chemical calculations (Nakai and Ishikawa, 2014), was applied to formation and combustion reactions of simple organic molecules. The conventional ideal gas model (IGM) considerably overestimated the entropies of the liquid molecules. The HSM could significantly improve this overestimation; mean absolute deviations for the Gibbs energies of the formation and combustion reactions were (49.6, 26.7) for the IGM and (9.7, 5.4) for the HSM in kJ/mol.

  15. Prediction of the self-accelerating decomposition temperature (SADT) for liquid organic peroxides from differential scanning calorimetry (DSC) measurements.

    PubMed

    Malow, M; Wehrstedt, K D

    2005-04-11

    We present a prediction (estimation, calculation, screening) method for the estimation of the self-accelerating decomposition temperature (SADT) for liquid organic peroxides from differential scanning calorimetry (DSC) measurements based on the concepts of thermal explosion theory originally introduced by Semonov which are adopted to our problem assuming nth-order reaction kinetics. For the peroxides under investigation, we demonstrate good agreement with the experimental SADT. This method can be used as a quick and easy applicable method for the estimation of the critical temperatures.

  16. Partition Coefficients of Organic Compounds in New Imidazolium and Tetralkylammonium Based Ionic Liquids Using Inverse Gas Chromatography

    SciTech Connect

    Mutelet, Fabrice; Revelli, Anne-Laure; Jaubert, Jean-Noel; Sprunger, Laura; Acree, William; Baker, Gary A

    2010-01-01

    Partition coefficients of 51 organic compounds in two ionic liquids (IL), 1-ethyl-3-methylimidazolium dicyanamide and trimethylhexylammonium bis((trifluoromethyl)sulfonyl)amide, were measured using inverse gas chromatography from (322.5 to 352.5) K. These partition coefficients were converted into water-to-IL partition coefficients using the corresponding gas-to-water partition coefficients. Both sets of partition coefficients were analyzed using the Abraham solvation parameter model with cation-specific and anionspecific equation coefficients. The derived equations correlated the experimental gas-to-IL and water-to-IL partition coefficient data to within (0.12 and 0.14) log units, respectively.

  17. Development of a New Thermal HF Plasma Reactor for the Destruction of Radioactive Organic Halogen Liquid Wastes

    SciTech Connect

    Bournonville, B.; Meillot, E.; Girold, C.

    2006-07-01

    A newly patented process employing thermal plasma for destruction of radioactive organic halogen liquid wastes is proposed. This studied safe system can destroy a great variety of wastes, even mixed together, using plasma torch as high temperature source. At the exit of the process, only non-toxic products are formed as atmospheric gases, liquid water and halogen sodium salt. The process has been built with the help of thermodynamic and kinetic simulations. A good atomic stoichiometry is necessary for avoiding the formation of solid carbon (soot) or toxic COCl{sub 2}. That why liquid water is added to the waste in the plasma flow. Then, an introduction of air cools and dilutes the formed gases and adds oxidant agent achieving oxidation of explosive H{sub 2} and toxic CO. Due to the high concentration of hydrochloric acid, an efficient wet treatment using soda traps it. Subsequently, the exhaust gases are only composed of Ar, O{sub 2}, N{sub 2}, CO{sub 2} and H{sub 2}O. In the first experimental step, pure organic molecules, mixed or not, without halogen have been destroyed. The experimental results show that all the compounds have been completely destroyed and only CO{sub 2} and H{sub 2}O have been formed without formation of any toxic compound or soot. After these encouraging results, chlorinated compounds as dichloromethane or chloroform have been destroyed by the process. In this case, the results are close to the previous one with an important formation of hydrochloric acid, as expected, which was well trapped by the soda to respect the French norm of rejection. A specific parameter study has been done with dichloromethane for optimising the operating condition to experimentally observe the influence of different parameters of the process as the stoichiometry ratio between waste and water, the air addition flow, the waste flow. The final aim of this study is to develop a clean process for treatment of radioactive organic halogen compounds. A small scale reactor

  18. Combination of corona discharge ion mobility spectrometry with a novel reagent gas and two immiscible organic solvent liquid-liquid-liquid microextraction for analysis of clomipramine in biological samples.

    PubMed

    Saraji, Mohammad; Bidgoli, Ali Akbar Hajialiakbari; Khayamian, Taghi; Moradmand, Ali

    2011-12-02

    A novel and sensitive method based on combination of two immiscible organic solvents hollow fiber-based liquid-liquid-liquid microextraction and corona discharge ion mobility spectrometry (HF-LLLME-CD-IMS) was employed for the analysis of clomipramine in human urine and plasma. The effect of formic, acetic and propionic acid as the reagent gas (dopant) on the corona discharge ion mobility signal was investigated. The influence of dopant amount was also studied. Optimum mass flow rates of the dopants were 3.7, 1.1 and 1.0 μmol min(-1) for formic, acetic and propionic acid, respectively. Experimental parameters influencing the extraction efficiency of HF-LLLME, such as NaOH concentration as donor solution, ionic strength of the sample, stirring rate, and extraction time were investigated and optimized. Under the optimum conditions, analytical parameters such as linearity, precision and limit of detection were also evaluated. The linear dynamic range was from 1 to 100 μg L(-1) (r(2)=0.9980) and the limit of detection was 0.35 μg L(-1). Intra- and inter-day precisions were satisfactory with a relative standard deviation (RSD) of 5.9 and 6.7%, respectively. The proposed method was satisfactorily applied for the determination of clomipramine in human plasma and urine.

  19. Waste Tank Organic Safety Project: Analysis of liquid samples from Hanford waste tank 241-C-103

    SciTech Connect

    Pool, K.H.; Bean, R.M.

    1994-03-01

    A suite of physical and chemical analyses has been performed in support of activities directed toward the resolution of an Unreviewed Safety Question concerning the potential for a floating organic layer in Hanford waste tank 241-C-103 to sustain a pool fire. The analysis program was the result of a Data Quality Objectives exercise conducted jointly with staff from Westinghouse Hanford Company and Pacific Northwest Laboratory (PNL). The organic layer has been analyzed for flash point, organic composition including volatile organics, inorganic anions and cations, radionuclides, and other physical and chemical parameters needed for a safety assessment leading to the resolution of the Unreviewed Safety Question. The aqueous layer underlying the floating organic material was also analyzed for inorganic, organic, and radionuclide composition, as well as other physical and chemical properties. This work was conducted to PNL Quality Assurance impact level III standards (Good Laboratory Practices).

  20. Photochromic hybrid organic-inorganic liquid-crystalline materials built from nonionic surfactants and polyoxometalates: elaboration and structural study.

    PubMed

    Poulos, Andreas S; Constantin, Doru; Davidson, Patrick; Impéror, Marianne; Pansu, Brigitte; Panine, Pierre; Nicole, Lionel; Sanchez, Clément

    2008-06-17

    This work reports the elaboration and structural study of new hybrid organic-inorganic materials constructed via the coupling of liquid-crystalline nonionic surfactants and polyoxometalates (POMs). X-ray scattering and polarized light microscopy demonstrate that these hybrid materials, highly loaded with POMs (up to 18 wt %), are nanocomposites of liquid-crystalline lamellar structure (Lalpha), with viscoelastic properties close to those of gels. The interpretation of X-ray scattering data strongly suggests that the POMs are located close to the terminal -OH groups of the nonionic surfactants, within the aqueous sublayers. Moreover, these materials exhibit a reversible photochromism associated to the photoreduction of the polyanion. The photoinduced mixed-valence behavior has been characterized through ESR and UV-visible-near-IR spectroscopies that demonstrate the presence of W(V) metal cations and of the characteristic intervalence charge transfer band in the near-IR region, respectively. These hybrid nanocomposites exhibit optical properties that may be useful for applications involving UV-light-sensitive coatings or liquid-crystal-based photochromic switches. From a more fundamental point of view, these hybrid materials should be very helpful models for the study of both the static and dynamic properties of nano-objects confined within soft lamellar structures.

  1. A method for determination of selenium in organic tissues using microwave digestion and liquid chromatography.

    PubMed

    Govasmark, Espen; Grimmett, Mark G

    2007-01-01

    An existing laboratory procedure for selenium analysis using open-vessel wet digestion and liquid chromatographic fluorescence determination was modified for use with microwave digestion. The proposed microwave digestion method eliminated the hazards associated with the use of HClO4 while maintaining excellent recoveries of selenium. A 2-step HNO3/H2O2 digestion procedure was developed. Digested samples were derivatized with 2,3-diaminonaphthalene, and the resultant piazselenol complex was measured fluorometrically using a liquid chromatograph. Measured values were in agreement with 9 different certified reference materials. The detection limit for this method was 0.54 ng Se/g tissue (3 sigma), and the calibration curve remained linear (r2 = 0.9968) up to 2 microg Se/g.

  2. Improving the Regeneration of CO₂-Binding Organic Liquids with a Polarity Change

    SciTech Connect

    Mathias, Paul M.; Afshar, Kash; Zheng, Feng; Bearden, Mark D.; Freeman, Charles J.; Andrea, Tamer; Koech, Phillip K.; Kutnyakov, Igor V.; Zwoster, Andy; Smith, Arnold R.; Jessop, Philip G.; Nik, Omid Ghafari; Heldebrant, David J.

    2013-01-01

    This paper describes an unusual solvent regeneration method unique to CO₂BOLs and other switchable ionic liquids; utilizing changes in polarity to shift the free energy of the system. The degree of CO₂ loading in CO₂BOLs is known to control the polarity of the solvent; conversely, polarity could be exploited as a means to control CO₂ loading. In this process, a chemically inert non-polar “antisolvent” is added to aid in de-complexing CO₂ from a CO₂-rich CO₂BOL. The addition of this polarity assist reduces temperatures required for regeneration of CO₂BOLs by as much as 76 °C. The lower regeneration temperatures realized with this polarity change allow for reduced solvent attrition and thermal degradation. Furthermore, the polarity assist shows considerable promise for reducing regeneration energy of CO₂BOL solvents, and separation of the CO₂BOL from the antisolvent is as simple as cooling the mixture below the upper critical solution temperature. Vapour-liquid equilibrium and liquid-liquid equilibrium measurements of a candidate CO₂BOL with CO₂ with and without an antisolvent were completed. From this data, we present the evidence and impacts of a polarity change on a CO₂BOL. Thermodynamic models and analysis of the system were constructed using ASPEN Plus, and forecasts preliminary process configurations and feasibility are also presented. Lastly, projections of solvent performance for removing CO₂ from a sub-critical coal fired power plant (total net power and parasitic load) are presented with and without this polarity assist and compared to DOE’s Case 10 MEA baseline.

  3. Numerical simulation of the self-organization of convective structures in a thin layer of liquid

    NASA Astrophysics Data System (ADS)

    Shishkova, I. N.; Levashov, V. Yu.; Kryukov, A. P.

    2012-05-01

    Complex convective structures observed experimentally in a thin layer of liquid are investigated numerically. To study this kind of phenomena, a mathematical model is suggested based on the interaction of two such opposite factors as the randomness of convective motions in the medium of interest as a whole and intensification of these motions by local sources that introduce correlations into a random process. The results obtained by mathematical simulation qualitatively reflect the most characteristic phenomena noted in the experiments.

  4. Dispersive liquid-liquid microextraction method based on solidification of floating organic drop for extraction of organochlorine pesticides in water samples.

    PubMed

    Leong, Mei-I; Huang, Shang-Da

    2009-11-06

    A new simple and rapid dispersive liquid-liquid microextraction method has been developed for the extraction and analysis of organochlorine pesticides (OCPs) in water samples. The method is based on the solidification of a floating organic drop (DLLME-SFO) and is combined with gas chromatography/electron capture detection (GC/ECD). Very little solvent is required in this method. The disperser solvent (200microL acetonitrile) containing 10microL hexadecane (HEX) is rapidly injected by a syringe into the 5.0mL water sample. After centrifugation, the fine HEX droplets (6+/-0.5microL) float at the top of the screw-cap test tube. The test tube is then cooled in an ice bath. After 5min, the HEX solvent solidifies and is then transferred into a conical vial, where it melts quickly at room temperature, and 1microL of it is injected into a gas chromatograph for analysis. Under optimum conditions, the enrichment factors and extraction recoveries are high and range between 37-872 and 82.9-102.5%, respectively. The linear range is wide (0.025-20microgL(-1)), and the limits of detection are between 0.011 and 0.11microgL(-1) for most of the analytes. The relative standard deviation (RSD) for 1microgL(-1) of OCPs in water was in the range of 5.8-8.8%. The performance of the method was gauged by analyzing samples of lake and tap water.

  5. Impact of air ions of both polarity on evaporation of certain organic and inorganic liquids

    NASA Astrophysics Data System (ADS)

    Barthakur, N. N.; Al-Kanani, T.

    1989-06-01

    Air ions of both polarity, produced by corona electrodes, were used to evaporate to dryness liquid samples of ethyl alcohol (EA), water (W), and carbon tetrachloride (CTC). Drying times were determined with a beta-ray gauge. Ion exposed samples of EA, W, and CTC dried, respectively, 2.3, 3.2, and 5.4 times faster than the corresponding control samples when exposed simultaneously to 0.94×1012 positive and 1.83×1012 negative air ions cm-2s-1 under the same laboratory conditions. Drying by corona discharge could be explained by three different mechanisms. Electric wind caused by the ionic drag is proposed as the principal driving force for the observed enhancement of evaporation. The decrease in free energy of a dielectric in the presence of an electric field compared to its absence may have increased the escaping tendency of the molecules of the treated liquids. The turbulence in the liquids created by the rotational effect on the dielectric molecules by the electric field may also be a factor in further enhancing the mass transfer rates from the samples.

  6. Application of the compensated Arrhenius formalism to fluidity data of polar organic liquids.

    PubMed

    Petrowsky, Matt; Fleshman, Allison M; Frech, Roger

    2013-03-14

    The temperature dependence of viscosity (the reciprocal of fluidity) in polar liquids has been studied for over a century, but the available theoretical models have serious limitations. Consequently, the viscosity is often described with empirical equations using adjustable fitting parameters that offer no insight into the molecular mechanism of transport. We have previously reported a novel approach called the compensated Arrhenius formalism (CAF) to describe ionic conductivity, self-diffusion, and dielectric relaxation in terms of molecular and system properties. Here the CAF is applied to fluidity data of pure n-acetates, 2-ketones, n-nitriles, and n-alcohols over the temperature range 5-85 °C. The fluidity is represented as an Arrhenius-like expression that includes a static dielectric constant dependence in the exponential prefactor. The dielectric constant dependence results from the dependence of mass and charge transport on the molecular dipole moment and the solvent dipole density. The CAF is the only self-consistent description of fluid transport in polar liquids written solely in terms of molecular and system parameters. A scaling procedure is used to calculate the activation energy for transport. We find that the activation energies for fluidity of the aprotic liquids are comparable in value, whereas a higher average E(a) value is observed for the n-alcohol data. Finally, we contrast the molecular description of transport presented here with the conventional hydrodynamic model.

  7. Mechanical Properties of Organic Materials Used in Superconducting Magnets Irradiated by Gamma Rays at Liquid Nitrogen Temperature

    SciTech Connect

    Nakamoto, T.; Kimura, N.; Makida, Y.; Ogitsu, T.; Ohhata, H.; Yamamoto, A.; Idesaki, A.; Morishita, N.; Itoh, H.; Kamiya, T.

    2006-03-31

    Radiation resistance of organic materials used in superconducting magnets for a 50 GeV-750 kW proton beam line for the J-PARC neutrino experiment was studied with respect to mechanical properties. Specimens cooled at a liquid nitrogen temperature of 77 K were irradiated by gamma rays from 60Co with the maximum dose beyond 10 MGy. The flexural strength of glass-fiber reinforced plastics (GFRPs), the tear strength of polyimide films and the tensile lap-shear strength of adhesive films were evaluated. It was verified that the organic materials used in the superconducting magnets have the sufficient radiation resistance, and the degradation of their mechanical properties after the 10 years operation was estimated to be negligible.

  8. One-dimensional subsurface transport of a nonaqueous phase liquid containing sparingly water soluble organics: A front-tracking model

    SciTech Connect

    Ryan, P.A.; Cohen, Y. )

    1991-07-01

    A one-dimensional multiphase mass transport model for the migration of a nonaqueous phase liquid (NAPL) containing sparingly water soluble organics in the unsaturated soil zone is described. The multiphase NAPL transport (MUNT) model consists of a two-phase immiscible flow model linked to a four-phase chemical transport model. The immiscible flow model incorporates a front-tracking algorithm to determine the front of the invading NAPL as a function of penetration time. The NAPL penetration toward groundwater is shown to be a function of four dimensionless groups: NAPL capillary number, the ratio of the NAPL Reynolds number to the NAPL Froude number, and the ratio of the defending phase to NAPL phase densities and viscosities. Simulations for the migration of organic chemicals show that their concentration in the air and aqueous phases past the front can be significant.

  9. Performance of different C18 columns in reversed-phase liquid chromatography with hydro-organic and micellar-organic mobile phases.

    PubMed

    Ruiz-Angel, M J; Pous-Torres, S; Carda-Broch, S; García-Alvarez-Coque, M C

    2014-05-30

    Column selection in reversed-phase liquid chromatography (RPLC) can become a challenge if the target compounds interact with the silica-based packing. One of such interactions is the attraction of cationic solutes to the free silanols in silica-based columns, which is a slow sorption-desorption interaction process that gives rise to tailed and broad peaks. The effect of silanols is minimised by the addition of a competing agent in the mobile phase, such as the anionic surfactant sodium dodecyl sulphate (SDS). In micellar-organic RPLC, the adsorption of an approximately fixed amount of SDS monomers gives rise to a stable modified stationary phase, with properties remarkably different from those of the underlying bonded phase. The chromatographic behaviour (in terms of selectivity, analysis time and peak shape) of eight C18 columns in the analysis of weakly acidic phenols and basic β-blockers was examined with hydro-organic and micellar-organic mobile phases. The behaviour of the columns differed significantly when the cationic basic drugs were eluted with hydro-organic mobile phases. With micellar-organic mobile phases, the adsorption of surfactant, instead of making the columns similar, gave rise to a greater diversity of behaviours (especially in terms of selectivity and analysis time), for both groups of phenols and β-blockers, which should be explained by the residual effect of the underlying bonded stationary phase and the different amount of surfactant covering the packing. Therefore, the implementation of a micellar-organic procedure in RPLC will depend significantly on the selected type of C18 column.

  10. Analyzing water soluble soil organics as Trifluoroacetyl derivatives by liquid state proton nuclear magnetic resonance

    Treesearch

    Felipe Garza Sanchez; Zakiya Holmes Leggett; Sabapathy Sankar

    2005-01-01

    In forested ecosystems, water soluble organics play an important role in soil processes including carbon and nutrient turnover, microbial activity and pedogenesis. The quantity and quality (i.e., chemistry) of these materials is sensitive to land management practices. Monitoring alterations in the chemistry of water soluble organics resulting from land management...

  11. Thermal and Optical Modulation of the Carrier Mobility in OTFTs Based on an Azo-anthracene Liquid Crystal Organic Semiconductor.

    PubMed

    Chen, Yantong; Li, Chao; Xu, Xiuru; Liu, Ming; He, Yaowu; Murtaza, Imran; Zhang, Dongwei; Yao, Chao; Wang, Yongfeng; Meng, Hong

    2017-03-01

    One of the most striking features of organic semiconductors compared with their corresponding inorganic counterparts is their molecular diversity. The major challenge in organic semiconductor material technology is creating molecular structural motifs to develop multifunctional materials in order to achieve the desired functionalities yet to optimize the specific device performance. Azo-compounds, because of their special photoresponsive property, have attracted extensive interest in photonic and optoelectronic applications; if incorporated wisely in the organic semiconductor groups, they can be innovatively utilized in advanced smart electronic applications, where thermal and photo modulation is applied to tune the electronic properties. On the basis of this aspiration, a novel azo-functionalized liquid crystal semiconductor material, (E)-1-(4-(anthracen-2-yl)phenyl)-2-(4-(decyloxy)phenyl)diazene (APDPD), is designed and synthesized for application in organic thin-film transistors (OTFTs). The UV-vis spectra of APDPD exhibit reversible photoisomerizaton upon photoexcitation, and the thin films of APDPD show a long-range orientational order based on its liquid crystal phase. The performance of OTFTs based on this material as well as the effects of thermal treatment and UV-irradiation on mobility are investigated. The molecular structure, stability of the material, and morphology of the thin films are characterized by thermal gravimetric analysis (TGA), polarizing optical microscopy (POM), (differential scanning calorimetry (DSC), UV-vis spectroscopy, atomic force microscopy (AFM), and scanning tunneling microscopy (STM). This study reveals that our new material has the potential to be applied in optical sensors, memories, logic circuits, and functional switches.

  12. Isolation, characterization, and catalytic properties of a novel lipase which is activated in ionic liquids and organic solvents.

    PubMed

    Akbari, Neda; Daneshjoo, Somayeh; Akbari, Jafer; Khajeh, Khosro

    2011-10-01

    A novel extracellular lipase with organic solvent tolerance was isolated from a local Pseudomonas species. The lipase gene was cloned and expressed in Escherichia coli as a heterologous host and purified by affinity chromatography. The activity of purified lipase was investigated in the presence of imidazolium-based ionic liquids (ILs) such as EMIM[Cl], BMIM[Cl], and HMIM[Cl]. It has been found that the activity of treated lipase with ILs was higher than untreated control in the hydrolysis reaction. Also, the results indicated that the enzymatic activity strongly depends on IL concentration in reaction media. The best concentration of the IL was 30%, 45%, and 50% (v/v) for HMIM[Cl], BMIM[Cl], and EMIM[Cl], respectively. Additionally, the enzyme exhibited excellent stability in the presence of 25% of n-hexane, toluene, acetone, and t-butanol. The optimum values of pH and temperature were determined 10 and 55 °C, respectively. The K (m) and V (max) values were calculated 0.4 mM and 1.92 U/ml, respectively, using p-nitrophenyl palmitate as substrate. With respect to the biochemical properties of the newly isolated lipase such as high-level stability and noticeable activity in the presence of organic solvents and ionic liquids, the newly isolated lipase seems to be a good candidate for environmental and industrial processes carried out in non-aqueous media.

  13. Impact of enhanced-flushing reagents and organic-liquid distribution on mass removal and mass-discharge reduction

    PubMed Central

    Akyol, Nihat Hakan; Lee, Ann Russo; Brusseau, Mark L

    2014-01-01

    A series of column and flow-cell experiments was conducted to investigate the impact of non-uniform organic-liquid distribution on the relationship between reductions in contaminant mass discharge and reductions in source zone mass under conditions of enhanced-solubilization flushing. Trichloroethene was used as the model organic liquid, and SDS (sodium dodecyl sulfate) and ethanol were used as representative enhanced-flushing reagents. The results were compared to those of water-flood control experiments. Concentrations of trichloroethene in the effluent exhibited multi-step behavior with time, wherein multiple secondary periods of quasi steady state were observed. This non-ideal behavior was observed for both the water-flood and enhanced-flushing experiments. For all flow-cell experiments, the later stage of mass removal was controlled by the more poorly- accessible mass associated with higher-saturation zones. The profiles relating reductions in contaminant mass discharge and reductions in mass exhibited generally similar behavior for both the water-flood and enhanced-flushing experiments. This indicates that while the rates and magnitudes of mass removal are altered by the presence of a solubilization-reagent solution, the fundamental mass-removal process is not. The profiles obtained for the flow-cell systems differed from those obtained for the column systems, highlighting the impact of source-zone heterogeneity on mass-removal behavior. PMID:24563557

  14. Impact of enhanced-flushing reagents and organic-liquid distribution on mass removal and mass-discharge reduction.

    PubMed

    Akyol, Nihat Hakan; Lee, Ann Russo; Brusseau, Mark L

    2013-10-01

    A series of column and flow-cell experiments was conducted to investigate the impact of non-uniform organic-liquid distribution on the relationship between reductions in contaminant mass discharge and reductions in source zone mass under conditions of enhanced-solubilization flushing. Trichloroethene was used as the model organic liquid, and SDS (sodium dodecyl sulfate) and ethanol were used as representative enhanced-flushing reagents. The results were compared to those of water-flood control experiments. Concentrations of trichloroethene in the effluent exhibited multi-step behavior with time, wherein multiple secondary periods of quasi steady state were observed. This non-ideal behavior was observed for both the water-flood and enhanced-flushing experiments. For all flow-cell experiments, the later stage of mass removal was controlled by the more poorly- accessible mass associated with higher-saturation zones. The profiles relating reductions in contaminant mass discharge and reductions in mass exhibited generally similar behavior for both the water-flood and enhanced-flushing experiments. This indicates that while the rates and magnitudes of mass removal are altered by the presence of a solubilization-reagent solution, the fundamental mass-removal process is not. The profiles obtained for the flow-cell systems differed from those obtained for the column systems, highlighting the impact of source-zone heterogeneity on mass-removal behavior.

  15. Impact of enhanced-flushing reagents and organic-liquid distribution on mass removal and mass-flux reduction

    NASA Astrophysics Data System (ADS)

    Akyol, N. H.; Russo, A. E.; Brusseau, M. L.

    2011-12-01

    A series of flow-cell experiments was conducted to investigate the impact of nonuniform organic-liquid distribution and flow-field heterogeneity on the relationship between source zone mass removal and mass flux reduction under conditions of enhanced-solubilization flushing. Sudan IV dyed trichloroethene was used as the model organic liquid, and SDS (sodium dodecyl sulfate) and ethanol were used as representative enhanced-flushing reagents. The results were compared to those of water-flood control experiments. Natural sand media with different median particle diameters and natural soils were used for these experiments to represent various pyhsically heterogeneous systems. Photographs were obtained throughout the course of the experiments to observe changes in source-zone distributions. The results showed that the heterogeneous systems exhibited multi-step mass-flux reduction/mass-removal behavior. This nonideal behavior was observed for both the water-flood and enhanced-flushing experiments. For all cases, the later stage of mass removal was controlled by the more poorly-accessible mass associated with higher-saturation zones.

  16. Determination of the solubility of low volatility liquid organic compounds in water using volatile-tracer assisted headspace gas chromatography.

    PubMed

    Zhang, Shu-Xin; Chai, Xin-Sheng; Barnes, Donald G

    2016-02-26

    This study reports a new headspace gas chromatographic method (HS-GC) for the determination of water solubility of low volatility liquid organic compounds (LVLOs). The HS-GC analysis was performed on a set of aqueous solutions containing a range of concentrations of toluene-spiked (as a tracer) LVLOs, from under-saturation to over-saturation. A plot of the toluene tracer GC signal vs. the concentration of the LVLO results in two lines of different slopes that intersect at the concentration corresponding to the compound's solubility in water. The results showed that the HS-GC method has good precision (RSD <6.3%) and good accuracy, in which the relative deference between the data measured by the HS-GC method and the reference method were within 6.0%. The HS-GC method is simple and particularly suitable for measuring the solubility of LVLOs at elevated temperatures. This approach should be of special interest to those concerned about the impact of the presence of low-volatility organic liquids in waters of environmental and biological systems.

  17. New extraction method for the analysis of linear alkylbenzene sulfonates in marine organisms. Pressurized liquid extraction versus Soxhlet extraction.

    PubMed

    Alvarez-Muñoz, D; Sáez, M; Lara-Martin, P A; Gómez-Parra, A; González-Mazo, E

    2004-10-15

    A new method has been developed for the determination of linear alkylbenzene sulfonates (LAS) from various marine organisms, and compared with Soxhlet extraction. The technique applied includes the use of pressurized liquid extraction (PLE) for the extraction stage, preconcentration of the samples, purification by solid-phase extraction (SPE) and analysis by liquid chromatography with fluorescence detection. The spiked concentrations were added to the samples (wet mass of the organisms: Solea senegalensis and Ruditapes semidecussatus), which were homogenized and agitated continuously for 25 h. The samples were extracted by pressurized hot solvent extraction using two different extraction temperatures (100 and 150 degrees C) and by traditional Soxhlet extraction. The best recoveries were obtained employing pressurized hot solvent extraction at 100 degrees C and varied in the range from 66.1 to 101.3% with a standard deviation of between 2 and 13. Detection limit was between 5 and 15 microg kg(-1) wet mass using HPLC-fluorescence detection. The analytical method developed in this paper has been applied for LAS determination in samples from a Flow-through exposure system with the objective of measuring the bioconcentration of this surfactant.

  18. Establishment and Characterization of an Air-Liquid Canine Corneal Organ Culture Model To Study Acute Herpes Keratitis

    PubMed Central

    Harman, Rebecca M.; Bussche, Leen; Ledbetter, Eric C.

    2014-01-01

    ABSTRACT Despite the clinical importance of herpes simplex virus (HSV)-induced ocular disease, the underlying pathophysiology of the disease remains poorly understood, in part due to the lack of adequate virus–natural-host models in which to study the cellular and viral factors involved in acute corneal infection. We developed an air-liquid canine corneal organ culture model and evaluated its susceptibility to canine herpesvirus type 1 (CHV-1) in order to study ocular herpes in a physiologically relevant natural host model. Canine corneas were maintained in culture at an air-liquid interface for up to 25 days, and no degenerative changes were observed in the corneal epithelium during cultivation using histology for morphometric analyses, terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling (TUNEL) assays, and transmission electron microscopy (TEM). Next, canine corneas were inoculated with CHV-1 for 48 h, and at that time point postinfection, viral plaques could be visualized in the corneal epithelium and viral DNA copies were detected in both the infected corneas and culture supernatants. In addition, we found that canine corneas produced proinflammatory cytokines in response to CHV-1 infection similarly to what has been described for HSV-1. This emphasizes the value of our model as a virus–natural-host model to study ocular herpesvirus infections. IMPORTANCE This study is the first to describe the establishment of an air-liquid canine corneal organ culture model as a useful model to study ocular herpesvirus infections. The advantages of this physiologically relevant model include the fact that (i) it provides a system in which ocular herpes can be studied in a virus–natural-host setting and (ii) it reduces the number of experimental animals needed. In addition, this long-term explant culture model may also facilitate research in other fields where noninfectious and infectious ocular diseases of dogs and humans are being studied. PMID

  19. [Rapid determination of eight organic acids in plant tissue by sequential extraction and high performance liquid chromatography].

    PubMed

    Huang, Tianzhi; Wang, Shijie; Liu Xiuming; Liu, Hong; Wu, Yanyou; Luo Xuqiang

    2014-12-01

    A sequential extraction method was developed to determine different forms of oxalate and seven oxalate-metabolism-related organic acids (glyoxylic acid, tartaric acid, glycolic acid, malic acid, acetic acid, citric acid, succinic acid) in plant tissue. The ultra-pure water was used as the extraction medium to obtain water-soluble oxalic acid and the other seven water-soluble organic acids. After the extraction of the water-soluble organic acids, the residues were extracted by dilute hydrochloric acid successively to get the acid-soluble oxalate which entered the liquid phase. A Hypersil ODS column was used with 5 mmol/L potassium dihydrogen phosphate buffer solution (pH 2. 8) as the mobile phase. The diode array detector was set at 210 nm and the column temperature at 30 °C with the injection volume of 5 µL. The flow rate was controlled at different times which allowed a good and rapid separation of the organic acids and hydrochloric acid. Under these conditions, the linear ranges of the method were 1-2000 mg/L for oxalic acid, 25-2,000 mg/L for acetic acid, and 10-2,000 mg/L for glyoxylic acid, tartaric acid, glycolic acid, malic acid, citric acid and succinic acid, with the correlation coefficients of the eight organic acids ≥ 0. 9996. The average recoveries of the eight organic acids in leaves and roots were 93. 5%-104. 4% and 85. 3%-105. 4% with RSDs of 0. 15% -2.43% and 0. 31%-2. 9% (n=7), respectively. The limits of detection ranged from 1 to 10 ng (S/N=3). The results indicated that the method is accurate, rapid and reproducible for the determination of organic acids in plant samples.

  20. Catalytic cracking of bio-oil to organic liquid product (OLP).

    PubMed

    Hew, K L; Tamidi, A M; Yusup, S; Lee, K T; Ahmad, M M

    2010-11-01

    The main objective of this paper is to find the optimum operating condition to upgrade the EFB-derived pyrolysis oil (bio-oil) to liquid fuel, mainly gasoline using Taguchi Method. From the analysis that has been done, it is found that the optimum operating condition for heterogeneous catalytic cracking process is at 400 degrees C, 15min of reaction time using 30g of catalyst weight where operating at this condition produced the highest yield of gasoline fraction which is 91.67 wt.%. This observation proves that EFB-derived pyrolysis oil could be upgraded via heterogeneous catalytic cracking to produce gasoline.

  1. Adsorptive separation on metal-organic frameworks in the liquid phase.

    PubMed

    Van de Voorde, Ben; Bueken, Bart; Denayer, Joeri; De Vos, Dirk

    2014-08-21

    While much attention of the MOF community has been devoted to adsorption and purification of gases, there is now also a vast body of data on the capability of MOFs to separate and purify liquid mixtures. Initial studies focused on separation of petrochemicals in apolar backgrounds, but the attention has moved now to the separation of complex, e.g. chiral compounds, and to the isolation of biobased compounds from aqueous media. We here give an overview of most of the existing literature, with an accent on separation mechanisms and structure-selectivity relationships.

  2. Products of the radical initiated oxidation of model solid and liquid organic acid particles in simulated "clean" and "polluted" environments.

    NASA Astrophysics Data System (ADS)

    Renbaum, L. H.; Smith, G. D.

    2009-05-01

    Using a flow tube reactor coupled to a chemical ionization mass spectrometer, the Cl-initiated oxidation of solid and supercooled liquid organic acid particles were investigated at 293 K. In creating aerosols of species which are able to be supercooled or solid at room temperature, it is possible to distinguish the effect of phase on particle reactivity and product formation. In a clean atmosphere, where there are negligible concentrations of NOx, the primary fate of peroxy radicals (formed from H-abstraction by Cl and OH radicals in the presence of O2) are their reactions to form ketone and alcohol products. These products are then able to undergo further oxidation to form multiply oxidized products. The formation of low-molecular weight volatile species may also be important in the oxidative aging of organic aerosols, however neither the mechanism of their formation nor their formation yields are well understood. We have shown that, for equivalent Cl exposures, more multiply-oxidized species as well as more low-molecular-weight species were created from the oxidation of solid particles than from liquid particles. The findings from these studies suggest that slower diffusion of the oxidation products in solid particles confines them to the surface where they continue to react with Cl radicals producing more-highly- functionalized products which may decompose more readily. By introducing nitric oxide to the flow tube reaction system, we show that in a polluted atmosphere, where NOx is present in significant concentrations, organic nitrate formation may become important on the surface of solid particles but not liquid particles as the RO2 are confined to the surface of solid particles (causing a enhanced localized concentration of RO2) where they may then react with ambient nitric oxide through the reaction RO2 + NO → RO2NO* → RONO2. These experiments of these model systems indicate that particle phase could be important in determining how organic aerosols

  3. Separation and determination of organic acids and phenolic compounds in fruit juices and drinks by high-performance liquid chromatography.

    PubMed

    Shui, Guanghou; Leong, Lai Peng

    2002-11-15

    A high-performance liquid chromatographic (HPLC) separation method with photo-diode array detection has been developed for the simultaneous determination of organic acids and phenolic compounds in juices and drinks. The chromatographic analysis of organic acids and phenolic compounds was carried out after their elution with sulphuric acid solution (pH 2.5) and methanol from C18 stationary phase. The mobile phase employed was sulphuric acid solution working at a flow-rate of 0.35 ml min(-1) for the whole run, while methanol was linearly increased to 0.45 ml min(-1) from 15 to 75 min followed by a 5-min isocratic elution. Ten organic acid acids were eluted in 30 min and 21 phenolic compounds, which include phenolic acids and flavonoids, were eluted in the following 50 min. Target compounds were detected at 215 nm. The repeatability (n=3) and between day precision of peak area (n=3) were all within 5.0% RSD. The within-day repeatability (n=3) and between-day precision (n=10) of retention times were within 0.3 and 1.6% relative standard deviation (RSD), respectively. The accuracy of the method was confirmed with an average recovery ranging between 85 and 106%. The method was successfully used to measure a variety of organic acids and phenolic compounds in juices and beverages. This method could also be used to evaluate the authenticity, spoilage or micronutrient contents of juices.

  4. [Simultaneous determination of organic acids and saccharides in lactic acid fermentation broth from biomass using high performance liquid chromatography].

    PubMed

    Ma, Rui; Ouyang, Jia; Li, Xin; Lian, Zhina; Cai, Cong

    2012-01-01

    Abstract: A high performance liquid chromatographic method for the simultaneous determination of organic acids and saccharides in lactic acid fermentation broth from biomass was developed. A Bio-Rad Aminex HPX-87H column was used at 55 degrees C. The mobile phase was 5 mmol/L sulfuric acid solution at a flow rate of 0.6 mL/min. The samples were detected by a refractive index detector (RID). The results showed that six organic acids and three saccharides in fermentation broth were completely separated and determined in 17 min. The linear correlation coefficients were above 0.999 8 in the range of 0.15-5.19 g/L. Under the optimized conditions, the recoveries of the organic acids and saccharides in Rhizopus oryzae fermentation broth at two spiked levels were in the range of 96.91%-103.11% with the relative standard deviations (RSDs, n = 6) of 0.81%-4.61%. This method is fast and accurate for the quantitative analysis of the organic acids and saccharides in microbial fermentation broths.

  5. Dual active ionic liquids and organic salts for inhibition of microbially influenced corrosion.

    PubMed

    Seter, Marianne; Thomson, Melanie J; Stoimenovski, Jelena; MacFarlane, Douglas R; Forsyth, Maria

    2012-06-18

    We describe a series of novel compounds designed to combat the bacterial growth that leads to microbially induced corrosion on steel in the marine environment. A synergistic effect of the ionic components in these dual active organic salts is demonstrated.

  6. Effective clean-up of organic liquid contaminants including BTEX, fuels, and organic solvents from the environment by poly(alkoxysilane) sorbents.

    PubMed

    Karadag, Koksal; Yati, Ilker; Bulbul Sonmez, Hayal

    2016-06-01

    Novel cross-linked poly(alkoxysilane)s, which can be used for the removal of organic liquid contaminants from water, were synthesized in one step, in a solvent free reaction medium, at moderately high temperature without using a catalyst. The synthesized polymers were characterized by Fourier transform infrared spectroscopy (FTIR), solid-state (13)C and (29)Si cross-polarization magic angle spinning (CPMAS) nuclear magnetic resonance (NMR), thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC) methods and elemental analysis. The swelling features of the poly(alkoxysilane)s were investigated in organic solvents and oils, such as dichloromethane, benzene, toluene, xylene, methyl tertiary butyl ether, and also some fuel derivatives, such as gasoline and euro diesel. All polymers have high-fast solvent uptake abilities, good reusability and thermal stability. The swelling features of the synthesized cross-linked polymers were evaluated by the swelling test, absorption-desorption kinetics. Thus, the results propose that cross-linked poly(alkoxysilane)s are suitable for the absorption of oil-organic pollutants from the water surface.

  7. A lipid bound actin meshwork organizes liquid phase separation in model membranes

    PubMed Central

    Honigmann, Alf; Sadeghi, Sina; Keller, Jan; Hell, Stefan W; Eggeling, Christian; Vink, Richard

    2014-01-01

    The eukaryotic cell membrane is connected to a dense actin rich cortex. We present FCS and STED experiments showing that dense membrane bound actin networks have severe influence on lipid phase separation. A minimal actin cortex was bound to a supported lipid bilayer via biotinylated lipid streptavidin complexes (pinning sites). In general, actin binding to ternary membranes prevented macroscopic liquid-ordered and liquid-disordered domain formation, even at low temperature. Instead, depending on the type of pinning lipid, an actin correlated multi-domain pattern was observed. FCS measurements revealed hindered diffusion of lipids in the presence of an actin network. To explain our experimental findings, a new simulation model is proposed, in which the membrane composition, the membrane curvature, and the actin pinning sites are all coupled. Our results reveal a mechanism how cells may prevent macroscopic demixing of their membrane components, while at the same time regulate the local membrane composition. DOI: http://dx.doi.org/10.7554/eLife.01671.001 PMID:24642407

  8. Reverse switching of surface roughness in a self-organized polydomain liquid crystal coating

    PubMed Central

    Liu, Danqing; Liu, Ling; Onck, Patrick R.; Broer, Dirk J.

    2015-01-01

    In this work we propose randomly ordered polydomain nematic liquid crystal polymer networks to reversibly generate notable jagged relief patterns at a polymer coating surface by light illumination. The domain size is controlled by the addition of traces of partly insoluble fluorinated acrylate. The photoresponse of the coating is induced by a small amount of copolymerized azobenzene monomers. Upon exposure to UV light, azobenzene undergoes trans to cis isomerization, resulting in a change in molecular order and packing within each domain. The extent of this effect and its directionality depends on the domain orientation. Localized to domain level, this morphological change forms large 3D spikes at the surface with a modulation amplitude of more than 20% of the initial thickness. The process is reversible; the surface topographical patterns erase within 10 s by stopping the light exposure. A finite element model is applied to simulate the surface topography changes of the polydomain coating. The simulations describe the formation of the topographic features in terms of light absorption and isomerization process as a function of the director orientation. The random director distribution leads to surface structures which were found to be in close agreement with the ones measured by interference microscopy. The effect of domain size on surface roughness and depth modulation was explored and related to the internal mechanical constraints. The use of nematic liquid crystal polydomains confined in a polymer network largely simplifies the fabrication of smart coatings with a prominent triggered topographic response. PMID:25775559

  9. Tuning quantum-dot organization in liquid crystals for robust photonic applications.

    PubMed

    Rodarte, Andrea L; Nuno, Zachary S; Cao, Blessing H; Pandolfi, Ronald J; Quint, Makiko T; Ghosh, Sayantani; Hein, Jason E; Hirst, Linda S

    2014-05-19

    Mesogenic ligands have the potential to provide control over the dispersion and stabilization of nanoparticles in liquid crystal (LC) phases. The creation of such hybrid materials is an important goal for the creation of soft tunable photonic devices, such as the LC laser. Herein, we present a comparison of isotropic and mesogenic ligands attached to the surface of CdSe (core-only) and CdSe/ZnS (core/shell) quantum dots (QDs). The mesogenic ligand's flexible arm structure enhances ligand alignment, with the local LC director promoting QD dispersion in the isotropic and nematic phases. To characterize QD dispersion on different length scales, we apply fluorescence microscopy, X-ray scattering, and scanning confocal photoluminescent imaging. These combined techniques demonstrate that the LC-modified QDs do not aggregate into the dense clusters observed for dots with simple isotropic ligands when dispersed in liquid crystal, but loosely associate in a fluid-like droplet with an average interparticle spacing >10 nm. Embedding the QDs in a cholesteric cavity, we observe comparable coupling effects to those reported for more closely packed isotropic ligands. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Determination of the lipophilicity (log P o/w) of organic compounds by microemulsion liquid chromatography.

    PubMed

    Xu, Liyuan; Li, Liangxing; Huang, Jindian; Yu, Suna; Wang, Jing; Li, Ning

    2015-01-01

    Four microemulsion liquid chromatography (MELC) systems and one micellar liquid chromatography (MLC) system have been evaluated as potential high-throughput screening platforms capable of modeling the partitioning behaviors of drug compounds in an n-octanol/water system and predicting their lipophilicity (i.e., log P values). The microemulsion mobile phases is consisted of sodium dodecyl sulfate (SDS), butanol, octane, heptanes, octanol and water. A linear solvation energy relationship (LSER)-based method was used to compare the MELC and MLC systems, as well as several other biochemical systems, and to identify the optimal system by comparing their Euclidean distances with the LSER coefficients. The most effective MELC system had a mobile phase consisting of 3.0% (w/w) SDS, 6.0% (w/w) butanol, 0.8% (w/w) octanol, and 90.2% (w/w) water (pH 6.4). The results showed that it gave superior results to the other chromatographic systems in terms of its ability to predict the log P values of drug compounds.

  11. Reverse switching of surface roughness in a self-organized polydomain liquid crystal coating.

    PubMed

    Liu, Danqing; Liu, Ling; Onck, Patrick R; Broer, Dirk J

    2015-03-31

    In this work we propose randomly ordered polydomain nematic liquid crystal polymer networks to reversibly generate notable jagged relief patterns at a polymer coating surface by light illumination. The domain size is controlled by the addition of traces of partly insoluble fluorinated acrylate. The photoresponse of the coating is induced by a small amount of copolymerized azobenzene monomers. Upon exposure to UV light, azobenzene undergoes trans to cis isomerization, resulting in a change in molecular order and packing within each domain. The extent of this effect and its directionality depends on the domain orientation. Localized to domain level, this morphological change forms large 3D spikes at the surface with a modulation amplitude of more than 20% of the initial thickness. The process is reversible; the surface topographical patterns erase within 10 s by stopping the light exposure. A finite element model is applied to simulate the surface topography changes of the polydomain coating. The simulations describe the formation of the topographic features in terms of light absorption and isomerization process as a function of the director orientation. The random director distribution leads to surface structures which were found to be in close agreement with the ones measured by interference microscopy. The effect of domain size on surface roughness and depth modulation was explored and related to the internal mechanical constraints. The use of nematic liquid crystal polydomains confined in a polymer network largely simplifies the fabrication of smart coatings with a prominent triggered topographic response.

  12. High-Resolution Electrospray Ionization Mass Spectrometry Analysis of Water- Soluble Organic Aerosols Collected with a Particle into Liquid Sampler

    SciTech Connect

    Bateman, Adam P.; Nizkorodov, Serguei; Laskin, Julia; Laskin, Alexander

    2010-10-01

    This work demonstrates the utility of a particle-into-liquid sampler (PILS) a technique traditionally used for identification of inorganic ions present in ambient or laboratory aerosols for the analysis of water soluble organic aerosol (OA) using high resolution electrospray ionization mass spectrometry (HR ESI-MS). Secondary organic aerosol (SOA) was produced from 0.5 ppm mixing ratios of limonene and ozone in a 5 m3 Teflon chamber. SOA was collected simultaneously using a traditional filter sampler and a PILS. The filter samples were later extracted with either water or acetonitrile, while the aqueous PILS samples were analyzed directly. In terms of peak intensities, types of detectable compounds, average O:C ratios, and organic mass to organic carbon ratios, the resulting high resolution mass spectra were essentially identical for the PILS and filter based samples. SOA compounds extracted from both filter/acetonitrile extraction and PILS/water extraction accounted for >95% of the total ion current in ESI mass spectra. This similarity was attributed to high solubility of limonene SOA in water. In contrast, significant differences in detected ions and peak abundances were observed for pine needle biomass burning organic aerosol (BBOA) collected with PILS and filter sampling. The water soluble fraction of BBOA is considerably smaller than for SOA, and a number of unique peaks were detectable only by the filter/acetonitrile method. The combination of PILS collection with HR-ESI-MS analysis offers a new approach for molecular analysis of the water-soluble organic fraction in biogenic SOA, aged photochemical smog, and BBOA.

  13. Phase Transition Enthalpy Measurements of Organic and Organometallic Compounds and Ionic Liquids. Sublimation, Vaporization, and Fusion Enthalpies from 1880 to 2015. Part 2. C11-C192

    NASA Astrophysics Data System (ADS)

    Acree, William; Chickos, James S.

    2017-03-01

    The second part of this compendium concludes with a collection of phase change enthalpies of organic molecules inclusive of C11-C192 reported over the period 1880-2015. Also included are phase change enthalpies including fusion, vaporization, and sublimation enthalpies for organometallic, ionic liquids, and a few inorganic compounds. Paper I of this compendium, published separately, includes organic compounds from C1 to C10 and describes a group additivity method for evaluating solid, liquid, and gas phase heat capacities as well as temperature adjustments of phase changes. Paper II of this compendium also includes an updated version of a group additivity method for evaluating total phase change entropies which together with the fusion temperature can be useful in estimating total phase change enthalpies. Other uses include application in identifying potential substances that either form liquid or plastic crystals or exhibit additional phase changes such as undetected solid-solid transitions or behave anisotropically in the liquid state.

  14. Concentration and fractionation of hydrophobic organic acid constituents from natural waters by liquid chromatography

    USGS Publications Warehouse

    Thurman, E.M.; Malcolm, R.L.

    1979-01-01

    A scheme is presented which used adsorption chromatography with pH gradient elution and size-exclusion chromatography to concentrate and separate hydrophobic organic acids from water. A review of chromatographic processes involved in the flow scheme is also presented. Organic analytes which appear in each aqueous fraction are quantified by dissolved organic carbon analysis. Hydrophobic organic acids in a water sample are concentrated on a porous acrylic resin. These acids usually constitute approximately 30-50 percent of the dissolved organic carbon in an unpolluted water sample and are eluted with an aqueous eluent (dilute base). The concentrate is then passed through a column of polyacryloylmorpholine gel, which separates the acids into high- and low-molecular-weight fractions. The high- and low-molecular-weight eluates are reconcentrated by adsorption chromatography, then are eluted with a pH gradient into strong acids (predominately carboxylic acids) and weak acids (predominately phenolic compounds). For standard compounds and samples of unpolluted waters, the scheme fractionates humic substances into strong and weak acid fractions that are separated from the low molecular weight acids. A new method utilizing conductivity is also presented to estimate the acidic components in the methanol fraction.

  15. Adsorption and Unfolding of Lysozyme at a Polarized Aqueous-Organic Liquid Interface.

    PubMed

    Arooj, Mahreen; Gandhi, Neha S; Kreck, Cara A; Arrigan, Damien W M; Mancera, Ricardo L

    2016-03-31

    The adsorption of proteins at the interface between two immiscible electrolyte solutions has been found to be key to their bioelectroactivity at such interfaces. Combined with interfacial complexation of organic phase anions by cationic proteins, this adsorption process may be exploited to achieve nanomolar protein detection. In this study, replica exchange molecular dynamics simulations have been performed to elucidate for the first time the molecular mechanism of adsorption and subsequent unfolding of hen egg white lysozyme at low pH at a polarized 1,2-dichloroethane/water interface. The unfolding of lysozyme was observed to occur as soon as it reaches the organic-aqueous interface, which resulted in a number of distinct orientations at the interface. In all cases, lysozyme interacted with the organic phase through regions rich in nonpolar amino acids, such that the side chains are directed toward the organic phase, whereas charged and polar residues were oriented toward the aqueous phase. By contrast, as expected, lysozyme in neat water at low pH does not exhibit significant structural changes. These findings demonstrate the key influence of the organic phase upon adsorption of lysozyme under the influence of an electric field, which results in the unfolding of its structure.

  16. Properties of Organic Liquids when Simulated with Long-Range Lennard-Jones Interactions.

    PubMed

    Fischer, Nina M; van Maaren, Paul J; Ditz, Jonas C; Yildirim, Ahmet; van der Spoel, David

    2015-07-14

    In order to increase the accuracy of classical computer simulations, existing methodologies may need to be adapted. Hitherto, most force fields employ a truncated potential function to model van der Waals interactions, sometimes augmented with an analytical correction. Although such corrections are accurate for homogeneous systems with a long cutoff, they should not be used in inherently inhomogeneous systems such as biomolecular and interface systems. For such cases, a variant of the particle mesh Ewald algorithm (Lennard-Jones PME) was already proposed 20 years ago (Essmann et al. J. Chem. Phys. 1995, 103, 8577-8593), but it was implemented only recently (Wennberg et al. J. Chem. Theory Comput. 2013, 9, 3527-3537) in a major simulation code (GROMACS). The availability of this method allows surface tensions of liquids as well as bulk properties to be established, such as density and enthalpy of vaporization, without approximations due to truncation. Here, we report on simulations of ≈150 liquids (taken from a force field benchmark: Caleman et al. J. Chem. Theory Comput. 2012, 8, 61-74) using three different force fields and compare simulations with and without explicit long-range van der Waals interactions. We find that the density and enthalpy of vaporization increase for most liquids using the generalized Amber force field (GAFF, Wang et al. J. Comput. Chem. 2004, 25, 1157-1174) and the Charmm generalized force field (CGenFF, Vanommeslaeghe et al. J. Comput. Chem. 2010, 31, 671-690) but less so for OPLS/AA (Jorgensen and Tirado-Rives, Proc. Natl. Acad. Sci. U.S.A. 2005, 102, 6665-6670), which was parametrized with an analytical correction to the van der Waals potential. The surface tension increases by ≈10(-2) N/m for all force fields. These results suggest that van der Waals attractions in force fields are too strong, in particular for the GAFF and CGenFF. In addition to the simulation results, we introduce a new version of a web server, http

  17. Synthesis of Amino Acid Precursors with Organic Solids in Planetesimals with Liquid Water

    NASA Technical Reports Server (NTRS)

    Kebukawa, Y; Misawa, S.; Matsukuma, J.; Chan, Q. H. S.; Kobayashi, J.; Tachibana, S.; Zolensky, M. E.

    2017-01-01

    Amino acids are important ingredients of life that would have been delivered to Earth by extraterrestrial sources, e.g., comets and meteorites. Amino acids are found in aqueously altered carbonaceous chondrites in good part in the form of precursors that release amino acids after acid hydrolysis. Meanwhile, most of the organic carbon (greater than 70 weight %) in carbonaceous chondrites exists in the form of solvent insoluble organic matter (IOM) with complex macromolecular structures. Complex macromolecular organic matter can be produced by either photolysis of interstellar ices or aqueous chemistry in planetesimals. We focused on the synthesis of amino acids during aqueous alteration, and demonstrated one-pot synthesis of a complex suite of amino acids simultaneously with IOM via hydrothermal experiments simulating the aqueous processing

  18. Birefringence-dependent linearly-polarized emission in a liquid crystalline organic light emitting polymer.

    PubMed

    Lee, Dong-Myoung; Lee, You-Jin; Kim, Jae-Hoon; Yu, Chang-Jae

    2017-02-20

    We investigated the linearly polarized emission of uniformly aligned poly(9,9-di-n-octylfluorenyl-2,7-diyl)-alt-(benzo[2,1,3]thia-diazol-4,8-diyl) (F8BT) with a liquid crystalline phase on a rubbed alignment layer. The polarization ratio, defined by the ratio of luminous intensities polarized parallel and perpendicular to the rubbed direction, gradually decreased with increasing thickness of the F8BT film. In the photoluminescence (PL) process, the polarized light is emitted throughout the whole F8BT film, while in the electroluminescence (EL) process, the polarized light is emitted at a certain region within the F8BT film. The thickness-dependent polarization ratios in both PL and EL processes were successfully described based on a simple model wherein the mean optical birefringence was expressed as a function of the thickness of the F8BT film.

  19. Partitioning behaviour of organic compounds between ionic liquids and supercritical fluids.

    PubMed

    Roth, Michal

    2009-03-06

    Applications and prospects of two-phase, tuneable solvent systems composed of ionic liquids (ILs) and supercritical fluids with an emphasis on supercritical carbon dioxide (scCO(2)) are reviewed. The IL-scCO(2) biphasic systems have increasingly been used in diverse fields of chemistry and technology, and some examples of these applications are mentioned here. Rational design of such applications can obviously benefit from pertinent data on phase equilibria including the partition coefficients of the prospective products and reactants between the two phases. Therefore, a reliable technique to measure the limiting partition coefficients would be of value. Here, the pros and cons of supercritical fluid chromatography in this respect are discussed. An overview of methods for predictive thermodynamic modelling of binary (IL-scCO(2)) and ternary (solute-IL-scCO(2)) systems is also included.

  20. Fingering Instabilities, Collapse, Avalanches and Self-Organized Criticality in Liquid Foams

    SciTech Connect

    Glazier, J. A.

    2002-11-29

    Foam is solid-like under low stress and liquid-like under high stress. It can sustain a small load elastically but a large one causes it to flow indefinitely. When shear stress is present, a pair of adjacent bubbles can be squeezed apart by another pair, leading to a T1 switching event. This local but abrupt topological change results in bubble-complexes rearranging from one metastable configuration to another. The resulting macroscopic dynamics is highly nonlinear and complex, involving large local motion that depends on correlations between nearby bubbles. The main goal of this study was to find the connection between the behavior of individual membranes and the whole network and to relate local rearrangements to global rheological properties of flowing foams.

  1. Organic holographic polymer dispersed liquid crystal distributed feedback laser from different diffraction orders

    NASA Astrophysics Data System (ADS)

    Liu, Minghuan; Liu, Yonggang; Zhang, Guiyang; Peng, Zenghui; Li, Dayu; Ma, Ji; Xuan, Li

    2016-11-01

    Holographic polymer dispersed liquid crystal (HPDLC) based distributed feedback (DFB) lasers were prepared with poly (-methoxy-5-(2‧-ethyl-hexyloxy)-1,4-phenylene-vinylene) (MEH-PPV) film as the active medium layer. The HPDLC grating film was fabricated via holographic induced photopolymerization. The pure film spectra of MEH-PPV and the amplified spontaneous emission (ASE) spectrum were investigated. The laser device was single-longitudinal mode operation. The tunability of the HPDLC DFB laser was achieved by selecting different grating periods. The lasing performances were also characterized and compared from different diffraction orders. The lasing threshold increased with the diffraction order and the third order laser possessed the largest conversion efficiency in this device. The experimental results were in good agreement with the theoretical calculations.

  2. FDTD analysis of photonic nanojet from self-organized liquid crystal microsystems

    NASA Astrophysics Data System (ADS)

    Okajima, Akiko; Matsui, Tatsunosuke

    2014-03-01

    Since Chen et al. reported on the photonic nanojet (PNJ), many researches have been carried out from various viewpoints such as fundamental physics and device applications. We have numerically analyzed, based on the finite-difference time-domain (FDTD) method, generation of PNJ from microcylinders incorporating the liquid crystals (LCs) with radial hedgehog and tangential alignments, in which the director of LC molecules is perpendicular or parallel to the LC/matrix interface. For the radial hedgehog alignment of LC molecules, the PNJ from LC microcylinders is separated into two beams. For the tangential alignment of LC molecules, we show that the PNJ from LC microcylinders are uniquely polarized reflecting birefringence of LCs, which cannot be obtained using optically isotropic microdroplets or microcylinders. By using the LC micro-systems, we may obtain a rich variety of PNJ with electrical tunability.

  3. Preliminary assessment of systems for deriving liquid and gaseous fuels from waste or grown organics

    NASA Technical Reports Server (NTRS)

    Graham, R. W.; Reynolds, T. W.; Hsu, Y. Y.

    1976-01-01

    The overall feasibility of the chemical conversion of waste or grown organic matter to fuel is examined from the technical, economic, and social viewpoints. The energy contribution from a system that uses waste and grown organic feedstocks is estimated as 4 to 12 percent of our current energy consumption. Estimates of today's market prices for these fuels are included. Economic and social issues are as important as technology in determining the feasibility of such a proposal. An orderly program of development and demonstration is recommended to provide reliable data for an assessment of the viability of the proposal.

  4. Calculation of the Standard Molal Thermodynamic Properties of Crystalline, Liquid, and Gas Organic Molecules at High Temperatures and Pressures

    NASA Astrophysics Data System (ADS)

    Helgeson, Harold C.; Owens, Christine E.; Knox, Annette M.; Richard, Laurent

    1998-03-01

    Calculation of the thermodynamic properties of organic solids, liquids, and gases at high temperatures and pressures is a requisite for characterizing hydrothermal metastable equilibrium states involving these species and quantifying the chemical affinities of irreversible reactions of organic molecules in natural gas, crude oil, kerogen, and coal with minerals and organic, inorganic, and biomolecular aqueous species in interstitial waters in sedimentary basins. To facilitate calculations of this kind, coefficients for the Parameters From Group Contributions (PFGC) equation of state have been compiled for a variety of groups in organic liquids and gases. In addition, molecular weights, critical temperatures and pressures, densities at 25°C and 1 bar, transition, melting, and boiling temperatures ( Tt,Pr, Tm,Pr, and Tv,Pr, respectively) and standard molal enthalpies of transition (Δ H° t,Pr), melting (Δ H° m,Pr), and vaporization (Δ H° v,Pr) of organic species at 1 bar ( Pr) have been tabulated, together with an internally consistent and comprehensive set of standard molal Gibbs free energies and enthalpies of formation from the elements in their stable state at 298.15 K ( Tr) and Pr (Δ G° f and Δ H° f, respectively). The critical compilation also includes standard molal entropies ( S°) and volumes ( V°) at Tr and Pr, and standard molal heat capacity power function coefficients to compute the standard molal thermodynamic properties of organic solids, liquids, and gases as a function of temperature at 1 bar. These properties and coefficients have been tabulated for more than 500 crystalline solids, liquids, and gases, and those for many more can be computed from the equations of state group additivity algorithms. The crystalline species correspond to normal alkanes (C nH 2( n+1) ) with carbon numbers ( n, which is equal to the number of moles of carbon atoms in one mole of the species) ranging from 5 to 100, and 23 amino acids including glycine (C 2H 5NO

  5. Composition dependent structural organization in trihexyl(tetradecyl)phosphonium chloride ionic liquid-methanol mixtures

    SciTech Connect

    Gupta, Aditya; Sharma, Shobha; Kashyap, Hemant K.

    2015-04-07

    This article reports results from the molecular dynamics simulations on the structural arrangement of the ions and molecules in the mixtures of trihexyl(tetradecyl)phosphonium chloride ([P{sub 666,14}{sup +}][Cl{sup −}]) ionic liquid (IL) and methanol (MeOH) over the entire composition range. Effects of composition on the charge and polarity orderings have been investigated via computation of X-ray scattering structure function, S(q), and by using a partitioning scheme proposed for such multi-component mixtures. Except for the neat methanol liquid, the total S(q) shows two peaks in its intermolecular region for all the mole-fractions. The lowest q peak is dominated primarily by anion-anion, cation-anion, and methanol-anion correlations. Our results signify that the methanol bulk structure, which predominantly has short-distance characteristic correlations and is governed by polar group of methanol, is retained for x{sub IL} ≤ 0.1. Then, the mixture goes through gradual structural changes from methanol-like to the IL-like for 0.1 < x{sub IL} ≤ 0.7. The dipolar interaction between methanol molecules weakens in this range, and the structural landscape of the mixture is steered by strong ion-ion, anion-methanol, and nonpolar interactions. The IL-like structural arrangement is virtually recovered for x{sub IL} > 0.7. At all the compositions studied, while the cation head groups are predominantly solvated by anions and subsequently by methanol molecules, the polar hydroxyl group of methanol is preferentially solvated by the anions. The radial distribution functions of selected pair of atomic species have also confirmed these observations.

  6. Partition coefficients of some environmentally important organic compounds between 1-octanol and water from reversed-phase high-performance liquid chromatography

    SciTech Connect

    Ritter, S.; Hauthal, W.H. . Inst. fuer Physikalische Chemie); Maurer, G. . Lehrstuhl fuer Technische Thermodynamik)

    1994-07-01

    1-Octanol/water partition coefficients in infinite dilution of several phenol, indole, biphenyl, and naphthalene derivatives, a few polycyclic aromatic compounds, and some polyfunctional haloaromatics determined by using reversed-phase high-performance liquid chromatography (RP-HPLC) are reported. These data may be used for estimating the ecotoxicological impact of those compounds identified in brown coal liquids (e.g., hydroxyaromatic compounds), as well as for the extension of methods to correlate and predict partition coefficients in organic/aqueous liquid phases.

  7. Co-digestion of press liquids of source-sorted municipal organic waste in anaerobic sludge treatment of municipal wastewater treatment plants.

    PubMed

    Effenberger, Johannes; Jahn, Lydia; Kuehn, Volker

    2016-01-01

    This paper describes a semi-continuous laboratory-scale investigation of a potential co-substrate for mesophilic anaerobic sludge digestion in a municipal wastewater treatment plant. A feed liquid produced from source-sorted municipal organic waste by pretreatment with a screw press was subjected to the investigation. Quantities produced in press trials as well as the composition of the feed liquid are presented. Mass balances for N, P and chemical oxygen demand are given in order to verify the methane production of the feed liquid in co-digestion with sewage sludge at mesophilic conditions. Hydraulic retention time of the reactors were 14.7 to 16 d and organic loading rates were 1.5 to 2.7 kg volatile solids (VS) per cubic metre per day. The pretreatment by screw press is compared to the production of feed liquids with pulper-based pretreatment processes. While the addition of the feed liquid increased methane production by about 345 ml CH(4)/g VS(in), total solids of the feed liquid were reduced to about 63%. With respect to co-digestion at municipal wastewater treatment plants, several risks associated with the investigated feed liquid are outlined.

  8. Towards Organized Hybrid Nanomaterials at the Air/Water Interface Based on Liquid-Crystal/ZnO Nanocrystals.

    PubMed

    Paczesny, Jan; Wolska-Pietkiewicz, Małgorzata; Binkiewicz, Ilona; Wróbel, Zbigniew; Wadowska, Monika; Matuła, Kinga; Dzięcielewski, Igor; Pociecha, Damian; Smalc-Koziorowska, Julita; Lewiński, Janusz; Hołyst, Robert

    2015-11-16

    The ability to self-assemble nanosized ligand-stabilized metal oxide or semiconductor materials offers an intriguing route to engineer nanomaterials with new tailored properties from the disparate components. We describe a novel one-pot two-step organometallic approach to prepare ZnO nanocrystals (NCs) coated with deprotonated 4-(dodecyloxy)benzoic acid (i.e., an X-type liquid-crystalline ligand) as a model LC system (termed ZnO-LC1 NCs). Langmuir and Langmuir-Blodgett films of the resulting hybrids are investigated. The observed behavior of the ZnO NCs at the air/water interface is rationalized by invoking a ZnO-interdigitation process mediated by the anchored liquid-crystalline shell. The ordered superstructures form according to mechanism based on a ZnO-interdigitation process mediated by liquid crystals (termed ZIP-LC). The external and directed force applied upon compression at the air/water interface and the packing of the ligands that stabilize the ZnO cores drives the formation of nanorods of ordered internal structure. To study the process in detail, we follow a nontraditional protocol of thin-film investigation. We collect the films from the air/water interface in powder form (ZnO-LC1 LB), resuspend the powder in organic solvents and utilize otherwise unavailable experimental techniques. The structural and physical properties of the resulting superlattices were studied by using electron microscopy, atomic force microscopy, X-ray studies, dynamic light scattering, thermogravimetric analysis, UV/Vis absorption, and photoluminescence spectroscopy.

  9. Structure Determination of Unknown Organic Liquids Using NMR and IR Spectroscopy: A General Chemistry Laboratory

    ERIC Educational Resources Information Center

    Pavel, John T.; Hyde, Erin C.; Bruch, Martha D.

    2012-01-01

    This experiment introduced general chemistry students to the basic concepts of organic structures and to the power of spectroscopic methods for structure determination. Students employed a combination of IR and NMR spectroscopy to perform de novo structure determination of unknown alcohols, without being provided with a list of possible…

  10. Structure Determination of Unknown Organic Liquids Using NMR and IR Spectroscopy: A General Chemistry Laboratory

    ERIC Educational Resources Information Center

    Pavel, John T.; Hyde, Erin C.; Bruch, Martha D.

    2012-01-01

    This experiment introduced general chemistry students to the basic concepts of organic structures and to the power of spectroscopic methods for structure determination. Students employed a combination of IR and NMR spectroscopy to perform de novo structure determination of unknown alcohols, without being provided with a list of possible…

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

    SciTech Connect

    Morin, G.T.; Hughes, M.P.; Paugam, M.F.; Smith, B.D. )

    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.

  12. Tank 241-C-103 organic vapor and liquid characterization and supporting activities, Hanford Site, Richland, Washington. Environmental Assessment

    SciTech Connect

    Not Available

    1993-08-10

    The action proposed is to sample the vapor space and liquid waste and perform other supporting activities in Tank 241-C-103 located in the 241-C Tank Farm on the Hanford Site. Operations at Tank 241-C-103 are curtailed because of an unreviewed safety question (USQ) concerning flammability issues of the organic waste in the tank. This USQ must be resolved before normal operation and surveillance of the tank can resume. In addition to the USQ, Tank 241-C-103 is thought to be involved in several cases of exposure of individuals to noxious vapors. This safety issue requires the use of supplied air for workers in the vicinity of the tank. Because of the USQ, the US Department of Energy proposes to characterize the waste in the vapor space and the organic and aqueous layers, to determine the volume of the organic layer. This action is needed to: (1) assess potential risks to workers, the public, and the environment from continued routine tank operations and (2) provide information on the waste material in the tank to facilitate a comprehensive safety analysis of this USQ. The information would be used to determine if a flammable condition within the tank is credible. This information would be used to prevent or mitigate an accident during continued waste storage and future waste characterization. Alternatives to the proposed activities have been considered in this analysis.

  13. Immunoaffinity chromatography purification and ultrahigh performance liquid chromatography tandem mass spectrometry determination of tetrodotoxin in marine organisms.

    PubMed

    Zhang, Xiaojun; Yan, Zhongyong; Wang, Ying; Jiang, Tao; Wang, Jian; Sun, Xiumei; Guo, Yuanming

    2015-04-01

    A highly selective and sensitive method was developed for the determination of tetrodotoxin (TTX) in marine organisms by immunoaffinity chromatography (IAC) purification coupled with ultrahigh performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). An IAC column was prepared and used to cleanup the extracted samples. The operating conditions of the IAC column were optimized, and the capacity of new IAC column was found to be 1106 ng mL(-1), which was sufficient for TTX determination. The MS/MS conditions and UPLC mobile phase were also studied to optimize the operation conditions. Fortified marine organism samples at levels of 0.3-5.0 ng g(-1) were utilized, and the average recoveries were 86.5-103.6% with intra- and inter-day relative standard deviations less than 7.22 and 9.88%, respectively. The limits of detection and quantification were 0.1 and 0.3 ng g(-1), respectively. The method was later successfully applied for the determination of TTX in 100 marine organism samples collected from local markets.

  14. Liquid Adsorption of Organic Compounds on Hematite α-Fe2O3 Using ReaxFF.

    PubMed

    Chia, Chung-Lim; Avendaño, Carlos; Siperstein, Flor R; Filip, Sorin

    2017-09-13

    ReaxFF-based molecular dynamics simulations are used in this work to study the effect of the polarity of adsorbed molecules in the liquid phase on the structure and polarization of hematite (α-Fe2O3). We compared the adsorption of organic molecules with different polarities on a rigid hematite surface and on a flexible and polarizable surface. We show that the displacements of surface atoms and surface polarization in a flexible hematite model are proportional to the adsorbed molecule's polarity. The increase in electrostatic interactions resulting from charge transfer in the outermost solid atoms in a flexible hematite model results in better-defined adsorbed layers that are less ordered than those obtained assuming a rigid solid. These results suggest that care must be taken when parametrizing empirical transferable force fields because the calculated charges on a solid slab in vacuum may not be representative of a real system, especially when the solid is in contact with a polar liquid.