WorldWideScience

Sample records for based sanex solvent

  1. Minor actinide separation: simplification of the DIAMEX-SANEX strategy by means of novel SANEX processes

    Energy Technology Data Exchange (ETDEWEB)

    Geist, A. [Karlsruher Institut fuer Technologie - KIT, INE, P. O. Box 3640, 76021 Karlsruhe (Germany); Modolo, G.; Wilden, A.; Kaufholz, P. [Forschungszentrum Juelich GmbH, IEK-6, Juelich (Germany)

    2013-07-01

    The separation of An(III) from PUREX raffinate has previously been demonstrated by applying a DIAMEX process (i.e., co-extraction of An(III) and Ln(III) from HAR) followed by a SANEX process (i.e., selective extraction of An(III) from the DIAMEX product containing An(III) + Ln(III)). In line with process intensification issues, more compact processes have been developed: Recently, a 1c-SANEX process test was successfully performed, directly extracting An(III) from PUREX HAR. More recently, a new i-SANEX process was successfully tested. This process is based on the co-extraction of An(III) + Ln(III) into a TODGA solvent, followed by a selective back-extraction of An(III) by a water soluble complexing agent, in this case SO{sub 3}-Ph-BTP. In both cases, good recoveries were achieved, and very pure product solutions were obtained. However, both 1c-SANEX and i-SANEX used non-CHON chemicals. Nevertheless, these processes are a simplification to the DIAMEX + SANEX process as only one solvent is used. Finally, the new i-SANEX process is the most compact process. (authors)

  2. Innovative SANEX process for trivalent actinides separation from PUREX raffinate

    International Nuclear Information System (INIS)

    Recycling of nuclear spent fuel and reduction of its radiotoxicity by separation of long-lived radionuclides would definitely help to close the nuclear fuel cycle ensuring sustainability of the nuclear energy. Partitioning of the main radiotoxicity contributors followed by their conversion into short-lived radioisotopes is known as partitioning and transmutation strategy. To ensure efficient transmutation of the separated elements (minor actinides) the content of lanthanides in the irradiation targets has to be minimised. This objective can be attained by solvent extraction using highly selective ligands that are able to separate these two groups of elements from each other. The objective of this study was to develop a novel process allowing co-separation of minor actinides and lanthanides from a high active acidic feed solution with subsequent actinide recovery using just one cycle, so-called innovative SANEX process. The conditions of each step of the process were optimised to ensure high actinide separation efficiency. Additionally, screening tests of several novel lipophilic and hydrophilic ligands provided by University of Twente were performed. These tests were aiming in better understanding the influence of the extractant structural modifications onto An(III)/Ln(III) selectivity and complexation properties. Optimal conditions for minor actinides separation were found and a flow-sheet of a new innovative SANEX process was proposed. Tests using a single centrifugal contactor confirmed high Eu(III)/Am(III) separation factor of 15 while the lowest SFLn/Am obtained was 6,5 (for neodymium). In addition, a new masking agent for zirconium was found as a substitution for oxalic acid. This new masking agent (CDTA) was also able to mask palladium without any negative influence on An(III)/Ln(III). Additional tests showed no influence of CDTA on plutonium present in the feed solution unlike oxalic acid which causes Pu precipitation. Therefore, CDTA was proposed as a Zr

  3. Innovative SANEX process for trivalent actinides separation from PUREX raffinate

    Energy Technology Data Exchange (ETDEWEB)

    Sypula, Michal

    2013-07-01

    Recycling of nuclear spent fuel and reduction of its radiotoxicity by separation of long-lived radionuclides would definitely help to close the nuclear fuel cycle ensuring sustainability of the nuclear energy. Partitioning of the main radiotoxicity contributors followed by their conversion into short-lived radioisotopes is known as partitioning and transmutation strategy. To ensure efficient transmutation of the separated elements (minor actinides) the content of lanthanides in the irradiation targets has to be minimised. This objective can be attained by solvent extraction using highly selective ligands that are able to separate these two groups of elements from each other. The objective of this study was to develop a novel process allowing co-separation of minor actinides and lanthanides from a high active acidic feed solution with subsequent actinide recovery using just one cycle, so-called innovative SANEX process. The conditions of each step of the process were optimised to ensure high actinide separation efficiency. Additionally, screening tests of several novel lipophilic and hydrophilic ligands provided by University of Twente were performed. These tests were aiming in better understanding the influence of the extractant structural modifications onto An(III)/Ln(III) selectivity and complexation properties. Optimal conditions for minor actinides separation were found and a flow-sheet of a new innovative SANEX process was proposed. Tests using a single centrifugal contactor confirmed high Eu(III)/Am(III) separation factor of 15 while the lowest SF{sub Ln/Am} obtained was 6,5 (for neodymium). In addition, a new masking agent for zirconium was found as a substitution for oxalic acid. This new masking agent (CDTA) was also able to mask palladium without any negative influence on An(III)/Ln(III). Additional tests showed no influence of CDTA on plutonium present in the feed solution unlike oxalic acid which causes Pu precipitation. Therefore, CDTA was proposed as

  4. Counter-current tests to demonstrate the feasibility of extractant separation in DIAMEX-SANEX process

    International Nuclear Information System (INIS)

    The DIAMEX-SANEX process, studied at the CEA Marcoule, aims at recovering trivalent minor actinides selectively from PUREX raffinates, by solvent extraction. The objective is to decrease the inventory of radioactive waste. This route has the particularity to use different organic phase compositions during the process. For instance, at the actinide extraction step, the DMDOHEMA malonamide is used alone as the extractant, whereas it is mixed with HDHP, an acidic extractant, in the other parts of the process. Since the DIAMEX-SANEX process presents a single partition cycle, a complementary extractant separation step is implemented in order to recycle the DMDOHEMA alone with TPH in the front end of the process. Thanks to suitable DMDOHEMA flow rates, it is possible to monitor the HDHP concentration in the organic phase to fulfill the required compositions to allow the targeted performances to be achieved. Once the aqueous and organic solutions of the extraction system were optimized, a basic counter-current test was performed, without any cation, to study the hydrodynamics of the system during the extractant separation step (stripping and re-extraction of the HDHP). Suitable choice of implementation conditions allowed the extractant separation step to be mastered experimentally and further validated by carrying out some batch extraction experiments with organic samples taken during the counter current test. The second step of this concept demonstration consisted in implementing the whole flowsheet using a surrogate feed solution containing every fission products capable of being extracted by the organic phase. The cold test gave a lot of data about the recovery yields of these fission products and a comparison with computed ones was made. This paper gives the results obtained for these two cold tests, in preparation for the high level active test planned in the Atalante hot cells using a genuine PUREX raffinate. (authors)

  5. Partnew - New solvent extraction processes for minor actinides - final report; Partnew - Nouveaux procedes d'extraction par solvant pour les actinides mineurs - rapport final

    Energy Technology Data Exchange (ETDEWEB)

    Madic, C.; Testard, F.; Hudson, M.J.; Liljenzin, J.O.; Christiansen, B.; Ferrando, M.; Facchini, A.; Geist, A.; Modolo, G.; Gonzalez-Espartero, A.; Mendoza, J. de

    2004-07-01

    The objectives of the European project PARTNEW were to define solvent extraction processes for the partitioning of the minor actinides, Am and Cm, from the aqueous high active raffinate or high active concentrate issuing the reprocessing of nuclear spent fuels by the PUREX process. Eleven laboratories participated to the research: 1/ CEA-DEN (Marcoule), 2/ CEA-DSM (Saclay), 3/ UREAD (U.K.), 4/ CTU (Sweden), 5/ ITU (Germany), 6/ ENEA (Italy), 7/ PoliMi (Italy), 8/ FZK-INE (Germany), 9/ FZJ-ISR (Germany), 10/ CIEMAT (Spain) and 11/ UAM (Spain). The research was organised into eight work packages (WP): Basic and applied DIAMEX studies, using diamide extractants for the co-extraction of actinides(III) (An(III)) and lanthanides(III) (Ln(III)) nitrates (WP1 and WP2), Basic and applied SANEX studies based on the use of polydentate N-ligands for the An(III)/Ln(III) separation (WP3 and WP4), Basic and applied SANEX studies based on the use of synergistic mixtures made of bis-(chloro-phenyl)-di-thio-phosphinic acid + neutral O-bearing ligand, (WP5 and WP6), Basic SANEX studies for the An(III)/Ln(III) separation, based on the use of new S-bearing ligands, Basic and applied studies for the Am(III)/Cm(III) separation. The work done in the fundamental and applied domains was very fruitful. Several processes have been successfully tested with genuine high active raffinates and concentrate. (authors)

  6. Towards an optimized flow-sheet for a SANEX demonstration process using centrifugal contactors

    Energy Technology Data Exchange (ETDEWEB)

    Magnusson, D. [European Commission, Joint Research Center, Karlsruhe (Germany). Inst. for Transuranium Elements; Chalmers Univ. of Technology, Gothenburg (Sweden). Nuclear Chemistry, Dept. of Chemical and Biological Engineering; Christiansen, B.; Glatz, J.P.; Malmbeck, R.; Serrano-Purroy, D. [European Commission, Joint Research Center, Karlsruhe (Germany). Inst. for Transuranium Elements; Modolo, G. [Forschungszentrum Juelich GmbH (Germany). Inst. for Energy Research, Safety Research and Reactor Technology; Sorel, C. [Commissariat a l' Energie Atomique Valrho (CEA), DRCP/SCPS, Bagnols-sur-Ceze (France)

    2009-07-01

    The design of an efficient process flow-sheet requires accurate extraction data for the experimental set-up used. Often this data is provided as equilibrium data. Due to the small hold-up volume compared to the flow rate in centrifugal contactors the time for extraction is often too short to reach equilibrium D-ratios. In this work single stage kinetics experiments have been carried out to investigate the D-ratio dependence of the flow rate and to compare this with equilibrium batch experiments for a SANEX system based on CyMe{sub 4}-BTBP. The first centrifuge experiment was run with spiked solutions while in the second a genuine actinide/lanthanide fraction from a TODGA process was used. Three different flow rates were tested with each set-up. The results show that even with low flow rates, only around 9% of the equilibrium D-ratio (Am) was reached for the extraction in the spiked test and around 16% in the hot test (the difference is due to the size of the centrifuges). In the hot test the lanthanide scrubbing was inefficient whereas in the stripping both the actinides and the lanthanides showed good results. Based on these results improvements of the suggested flow-sheet is discussed. (orig.)

  7. The separation of extractants implemented in the DIAMEX-SANEX process

    Energy Technology Data Exchange (ETDEWEB)

    Heres, Xavier [CEA-Marcoule, DEN/MAR/DRCP/SCPS, BP 17171, 30207 Bagnols-sur-Ceze Cedex (France); Baron, P.; Hill, C.; Ameil, E.; Martinez, I. [CEA-Marcoule, DEN/MAR/DRCP/SCPS, BP 17171, 30207 Bagnols-sur-Ceze Cedex (France); Rivalier, P. [CEA-Marcoule, DEN/MAR/DTEC/SGCS, BP 17171, 30207 Bagnols-sur-Ceze Cedex (France)

    2008-07-01

    DIAMEX-SANEX is a process developed at the Cea to recover selectively the actinides(III) after a COEX{sup TM} or a PUREX process, in order to significantly decrease the radiotoxicity of the ultimate waste produced by the nuclear industry. This liquid-liquid extraction process is based on the DIAMEX process, using a malonamide supplemented by an acidic extractant. Besides an actinide extraction step and a lanthanide stripping step are implemented an actinide(III) stripping step and an extractant splitting step. The latter is carried out to avoid interactions between these two extractants during the first co-extraction step of the actinides and the lanthanides. This paper gives some results obtained with di-n-hexyl phosphoric acid (HDHP), which fulfills the required criteria for process development. Batch experiments or cold counter-current tests showed that it is possible to separate this extractant from DMDOHEMA. HDHP can moreover maintain the lanthanides(III) in the organic phase when the actinides(III) are back extracted from the organic phase. (authors)

  8. Demonstration of Minor Actinide separation from a genuine PUREX raffinate by TODGA/TBP and SANEX reprocessing

    Energy Technology Data Exchange (ETDEWEB)

    Magnusson, D. [European Commission, Joint Research Center, Institute for Transuranium Elements, Postfach 2340 D-76125 Karlsruhe (Germany); Chalmers University of Technology, Nuclear Chemistry, Deparment of Chemical and Biological Engineering, Gothenburg (Sweden); Christiansen, B.; Glatz, J.P.; Malmbeck, R.; Serrano-Purroy, D. [European Commission, Joint Research Center, Institute for Transuranium Elements, Postfach 2340 D-76125 Karlsruhe (Germany); Modolo, G. [Forschungszentrum Juelich, Institute for Energy Research, Safety Research and Reactor Technology, D-52425 Juelich (Germany); Sorel, C. [Commissariat a l' Energie Atomique Valrho (CEA), DRCP/SCPS, BP17171, 30207 Bagnols-sur-Ceze (France)

    2008-07-01

    A genuine High Active Raffinate was produced from small scale Purex reprocessing of a UO{sub 2} spent fuel solution and used as feed for a subsequent TODGA/TBP process. In this process, efficient recovery of the trivalent Minor Actinides (MA) actinides could be demonstrated using a hot cell set-up of 32 centrifugal contactor stages. The feed decontamination factors obtained for Am and Cm were in the range of 4.10{sup 4} which corresponds to a recovery of more than 99.99 % in the product fraction. Trivalent lanthanides and Y were co-extracted, otherwise only a small part of the Ru ended up in the product. The collected actinide/lanthanide fraction was later used as feed for a Sanex (separation of actinides from lanthanides) process based on the CyMe{sub 4}-BTBP ligand. Preliminary results show recoveries of more than 99.9 % of Am, Cm and less than 0.1 % of the major lanthanides in the product. (authors)

  9. Acids and bases solvent effects on acid-base strenght

    CERN Document Server

    Cox, Brian G

    2013-01-01

    Acids and bases are ubiquitous in chemistry. Our understanding of them, however, is dominated by their behaviour in water. Transfer to non-aqueous solvents leads to profound changes in acid-base strengths and to the rates and equilibria of many processes: for example, synthetic reactions involving acids, bases and nucleophiles; isolation of pharmaceutical actives through salt formation; formation of zwitter- ions in amino acids; and chromatographic separation of substrates. This book seeks to enhance our understanding of acids and bases by reviewing and analysing their behaviour in non-aqueous solvents. The behaviour is related where possible to that in water, but correlations and contrasts between solvents are also presented.

  10. Optimal (Solvent) Mixture Design through a Decomposition Based CAMD methodology

    DEFF Research Database (Denmark)

    Achenie, L.; Karunanithi, Arunprakash T.; Gani, Rafiqul

    2004-01-01

    Computer Aided Molecular/Mixture design (CAMD) is one of the most promising techniques for solvent design and selection. A decomposition based CAMD methodology has been formulated where the mixture design problem is solved as a series of molecular and mixture design sub-problems. This approach is...... is able to overcome most of the difficulties associated with the solution of mixture design problems. The new methodology has been illustrated with the help of a case study involving the design of solvent-anti solvent binary mixtures for crystallization of Ibuprofen....

  11. 40 CFR 447.10 - Applicability; description of the oil-base solvent wash ink subcategory.

    Science.gov (United States)

    2010-07-01

    ...-base solvent wash ink subcategory. 447.10 Section 447.10 Protection of Environment ENVIRONMENTAL...-Base Solvent Wash Ink Subcategory § 447.10 Applicability; description of the oil-base solvent wash ink...-base ink where the tank washing system uses solvents. When a plant is subject to effluent...

  12. Molecular and supramolecular speciations of solvent extraction systems based on malonamide and/or dialkyl-phosphoric acids for An(III)/Ln(III); Speciations moleculaire et supramoleculaire de systemes d'extraction liquide-liquide a base de malonamide et/ou d'acides dialkylphosphoriques pour la separation An(III)/Ln(III)

    Energy Technology Data Exchange (ETDEWEB)

    Gannaz, B

    2006-06-15

    The solvent extraction system used in the DIAMEX-SANEX process, developed for the actinide(III)/lanthanide(III) separation, is based on the use of mixtures of the malonamide DMDOHEMA and a dialkyl-phosphoric acid (HDEHP or HDHP), in hydrogenated tetra-propylene. The complexity of these systems urges on a novel approach to improve the conventional methods (thermodynamics, solvent extraction) which hardly explain the macroscopic behaviors observed (3. phase, over-stoichiometry). This approach combines studies on both supramolecular (VPO, SANS, SAXS) and molecular (liquid-liquid extraction, ESI-MS, IR, EXAFS) speciations of single extractant systems (DMDOHEMA or HDHP in in n-dodecane) and their mixture. In spite of safety constraints due to the handling of radio-material, they were used in the studies as much as possible, like for SAXS measurements on americium-containing samples, a worldwide first-time. In each of the investigated systems, actinides(III) and lanthanides(III) are extracted to the organic phase in polar cores of reversed micelles, the inner and outer-sphere compositions of which are proposed. Thus, the 4f and 5f cations are extracted by reversed micelles such as [(DMDOHEMA){sub 2}M(NO{sub 3}){sub 3}]{sub inn} (DMDOHEMA){sub x}(HNO{sub 3}){sub z}(H{sub 2}O){sub w}]{sub out} and M(DHP){sub 3}(HDHP){sub y-3}(H{sub 2}O){sub w} with y = 3 to 6, for the single extractant systems. In the case of the two extractants system, the less concentrated one acts like a co-surfactant regarding the mixed aggregate formation [(DMDOHEMA){sub 2}M(NO{sub 3}){sub 3-v}(DHP){sub v}]{sub inn} [(DMDOFIEMA){sub x}(HDHP){sub y}(HNO{sub 3})z(H{sub 2}O){sub w}]{sub out}. (author)

  13. Effects of temperature and solvent concentration on the solvent crystallization of palm-based dihydroxystearic acid with isopropyl alcohol

    Institute of Scientific and Technical Information of China (English)

    Gregory F.L.Koay; Teong-Guan Chuah; Sumaiya Zainal-Abidin; Salmiah Ahmad; Thomas S.Y.Choong

    2012-01-01

    Palm-based dihydroxystearic acid of 69.55% purity was produced in a 500-kg-per-batch operation pilot plant and purified through solvent crystallization in a custom fabricated simultaneous batch crystallizer unit.The effects of temperature and solvent concentration on yield,particle size distribution and purity were studied.The purity was higher,while the yield and particle size were lower and smaller,respectively,at higher temperature and solvent concentration.The solvent crystallization process efficiency was rated at 66-69% when carried out with 70-80% isopropyl alcohol at 20 ℃.

  14. Improving agar electrospinnability with choline-based deep eutectic solvents.

    Science.gov (United States)

    Sousa, Ana M M; Souza, Hiléia K S; Uknalis, Joseph; Liu, Shih-Chuan; Gonçalves, Maria P; Liu, LinShu

    2015-09-01

    Very recently our group has produced novel agar-based fibers by an electrospinning technique using water as solvent and polyvinyl alcohol (PVA) as co-blending polymer. Here, we tested the deep eutectic solvent (DES), (2-hydroxyethyl)trimethylammonium chloride/urea prepared at 1:2 molar ratio, as an alternative solvent medium for agar electrospinning. The electrospun materials were collected with an ethanol bath adapted to a previous electrospinning set-up. One weight percent agar-in-DES showed improved viscoelasticity and hence, spinnability, when compared to 1 wt% agar-in-water and pure agar nanofibers were successfully electrospun if working above the temperature of sol-gel transition (∼80 °C). By changing the solvent medium we decreased the PVA concentration (5 wt% starting solution) and successfully produced composite fibers with high agar contents (50/50 agar/PVA). Best composite fibers were formed with the 50/50 and 30/70 agar/PVA solutions. These fibers were mechanically resistant, showed tailorable surface roughness and diverse size distributions, with most of the diameters falling in the sub-micron range. Both nano and micro forms of agar fibers (used separately or combined) may have potential for the design of new and highly functional agar-based materials. PMID:26116384

  15. How polar are choline chloride-based deep eutectic solvents?

    Science.gov (United States)

    Pandey, Ashish; Rai, Rewa; Pal, Mahi; Pandey, Siddharth

    2014-01-28

    Developing and characterizing green solvents with low toxicity and cost is one of the most important issues in chemistry. Deep Eutectic Solvents (DESs), in this regard, have shown tremendous promise. Compared to popular organic solvents, DESs possess negligible VOCs and are non-flammable. Compared to ionic liquids, which share many characteristics but are ionic compounds and not ionic mixtures, DESs are cheaper to make, much less toxic and mostly biodegradable. An estimate of the polarity associated with DESs is essential if they are to be used as green alternatives to common organic solvents in industries and academia. As no one physical parameter can satisfactorily represent solute-solvent interactions within a medium, polarity of DESs is assessed through solvatochromic optical spectroscopic responses of several UV-vis absorbance and molecular fluorescence probes. Information on the local microenvironment (i.e., the cybotactic region) that surrounds several solvatochromic probes [betaine dye, pyrene, pyrene-1-carboxaldehyde, 1-anilino-8-naphthalene sulfonate (ANS), p-toluidinyl-6-naphthalene sulfonate (TNS), 6-propionyl-2-(dimethylaminonaphthalene) (PRODAN), coumarin-153, and Nile Red] for four common and popular DESs formed from choline chloride combined with 1,2-ethanediol, glycerol, urea, and malonic acid, respectively, in 1 : 2 molar ratios termed ethaline, glyceline, reline, and maline is obtained and used to assess the effective polarity afforded by each of these DESs. The four DESs as indicated by these probe responses are found to be fairly dipolar in nature. Absorbance probe betaine dye and fluorescence probes ANS, TNS, PRODAN, coumarin-153, and Nile Red, whose solvatochromic responses are based on photoinduced charge-transfer, imply ethaline and glyceline, DESs formed using alcohol-based H-bond donors, to be relatively more dipolar in nature as compared to reline and maline. The pyrene polarity scale, which is based on polarity-induced changes in

  16. Opportunities for Bio-Based Solvents Created as Petrochemical and Fuel Products Transition towards Renewable Resources

    Directory of Open Access Journals (Sweden)

    James H. Clark

    2015-07-01

    Full Text Available The global bio-based chemical market is growing in size and importance. Bio-based solvents such as glycerol and 2-methyltetrahydrofuran are often discussed as important introductions to the conventional repertoire of solvents. However adoption of new innovations by industry is typically slow. Therefore it might be anticipated that neoteric solvent systems (e.g., ionic liquids will remain niche, while renewable routes to historically established solvents will continue to grow in importance. This review discusses bio-based solvents from the perspective of their production, identifying suitable feedstocks, platform molecules, and relevant product streams for the sustainable manufacturing of conventional solvents.

  17. Solvent-free Mechanosynthesis of Two Thermochromic Schiff Bases.

    Science.gov (United States)

    Kaitner, Branko; Zbačnik, Marija

    2012-09-01

    Two thermochromic Schiff bases mostly in keto-amine tautomeric form were obtained by means of mechanochemical synthesis. Both Schiff bases Compound 1 and Compound 2, respectively are derived from the same primary amine 2-amino-5-methylphenol. Salicylaldehyde was used as aldehyde component in preparation of 1, and o-vanillin as substituted salicylaldehyde component in synthesis of 2. Powder products of the neat grinding and liquid-assisted grinding syntheses of 1 and 2 were compared with the crystalline products, obtained by recrystallization from a small amount of solvent. Both raw powder and recrystallized products were characterized and compared by means of PXRD, DSC and IR. PMID:24061325

  18. 40 CFR 446.10 - Applicability; description of the oil-base solvent wash paint subcategory.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Applicability; description of the oil-base solvent wash paint subcategory. 446.10 Section 446.10 Protection of Environment ENVIRONMENTAL...-Base Solvent Wash Paint Subcategory § 446.10 Applicability; description of the oil-base solvent...

  19. The impact of solvent type and mixing ratios of solvents on the properties of polyurethane based electrospun nanofibers

    Science.gov (United States)

    Erdem, R.; Usta, İ.; Akalin, M.; Atak, O.; Yuksek, M.; Pars, A.

    2015-04-01

    Electrospun Polyurethane based nanofibrous membranes were fabricated from the solutions prepared with various volume ratios of N,N-dimethylformamide (DMF) and Tetrahydrofuran (THF). Properties of the blended solutions were analyzed in terms of viscosity and conductivity. The morphology of nanofibrous membranes were observed by SEM analysis. Experimental results revealed that the morphologies of polyurethane nanofiber membranes have been changed significantly with the solvent selection and mixing ratios of the solvents for the electrospinning. Diameter of the nanofibers was recorded in the range between 277 nm and 556 nm, respectively. Tensile strength and elongation measurements confirmed that mechanical characteristics of the nanofibrous membranes were strongly influenced by the fiber morphology and the uniformity.

  20. An Investigation of the Behavior of Solvent based Polycaprolactone ink for Material Jetting

    OpenAIRE

    Yinfeng He; Ricky D. Wildman; Chris J. Tuck; Steven D. R. Christie; Steven Edmondson

    2016-01-01

    An initial study of processing bioresorbable polycaprolactone (PCL) through material jetting was conducted using a Fujifilm Dimatix DMP-2830 material printer. The aim of this work was to investigate a potential solvent based method of jetting polycaprolactone. Several solvents were attempt to prepared PCL solvent based ink and 1, 4-dioxane was chosen with the consideration of both solubility and safety. The morphology of PCL formed under different substrate temperatures, droplet spacings were...

  1. Green solvent-based approaches for synthesis of nanomaterials

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The use of green solvents (including supercritical fluids and ionic liquids) in the synthesis of nanomaterials is highlighted. The methods described can not only reduce or eliminate the use or generation of substances hazardous to health and the environment, but can also be used to efficiently prepare nanomaterials with high performances. The unique characteristics of green solvents are responsible for the green features and unusual advantages of these approaches.

  2. EPR character of gadolinium complexes with noncyclic polyether Schiff bases and its solvent effects

    Institute of Scientific and Technical Information of China (English)

    姚克敏; 陈德余; 王晓南; 邓宁

    1996-01-01

    EPR characters of three new gadolinium complexes with noncydic polyether Schiff bases in powder or organic solvents, including various oxyethylene chain lengths and different substituting groups in ligands, are investigated respectively. Some regularities are summed up. The difference of EPR character in various solvents, particularly at different temperatures, has been examined. The ’single peak effect’ due to THF solvent at low temperature is observed for the first time. This phenomenon is explicated.

  3. Amine-based solvents regeneration in gas-liquid membrane contactor based on asymmetric PVTMS

    NARCIS (Netherlands)

    Volkov, A.V.; Tsarkov, S.E.; Goetheer, E.L.V.; Volkov, V.V.

    2015-01-01

    Asymmetric flat-sheet membranes made of poly(vinyltrimethylsilane) (PVTMS) were studied for the regeneration of amine-based absorption solvents in a membrane gas-liquid contactor at 100°C. It was shown that PVTMS membrane possesses good mechanical and chemical stability in contact with 4 M monoethan

  4. Solvent cleanup using base-treated silica gel solid adsorbent

    Energy Technology Data Exchange (ETDEWEB)

    Tallent, O.K.; Mailen, J.C.; Pannell, K.D.

    1984-06-01

    A solvent cleanup method using silica gel columns treated with either sodium hydroxide (NaOH) or lithium hydroxide (LiOH) has been investigated. Its effectiveness compares favorably with that of traditional wash methods. After treatment with NaOH solution, the gels adsorb HNO/sub 3/, dibutyl phosphate (DBP), UO/sub 2//sup 2 +/, Pu/sup 4 +/, various metal-ion fission products, and other species from the solvent. Adsorption mechanisms include neutralization, hydrolysis, polymerization, and precipitation, depending on the species adsorbed. Sodium dibutyl phosphate, which partially distributes to the solvent from the gels, can be stripped with water; the stripping coefficient ranges from 280 to 540. Adsorption rates are diffusion controlled such that temperature effects are relatively small. Recycle of the gels is achieved either by an aqueous elution and recycle sequence or by a thermal treatment method, which may be preferable. Potential advantages of this solvent cleanup method are that (1) some operational problems are avoided and (2) the amount of NaNO/sub 3/ waste generated per metric ton of nuclear fuel reprocessed would be reduced significantly. 19 references, 6 figures, 12 tables.

  5. Solvent cleanup using base-treated silica gel solid adsorbent

    International Nuclear Information System (INIS)

    A solvent cleanup method using silica gel columns treated with either sodium hydroxide (NaOH) or lithium hydroxide (LiOH) has been investigated. Its effectiveness compares favorably with that of traditional wash methods. After treatment with NaOH solution, the gels adsorb HNO3, dibutyl phosphate (DBP), UO22+, Pu4+, various metal-ion fission products, and other species from the solvent. Adsorption mechanisms include neutralization, hydrolysis, polymerization, and precipitation, depending on the species adsorbed. Sodium dibutyl phosphate, which partially distributes to the solvent from the gels, can be stripped with water; the stripping coefficient ranges from 280 to 540. Adsorption rates are diffusion controlled such that temperature effects are relatively small. Recycle of the gels is achieved either by an aqueous elution and recycle sequence or by a thermal treatment method, which may be preferable. Potential advantages of this solvent cleanup method are that (1) some operational problems are avoided and (2) the amount of NaNO3 waste generated per metric ton of nuclear fuel reprocessed would be reduced significantly. 19 references, 6 figures, 12 tables

  6. Protease activation in glycerol-based deep eutectic solvents

    OpenAIRE

    Zhao, Hua; Baker, Gary A.; Holmes, Shaletha

    2011-01-01

    Deep eutectic solvents (DESs) consisting of mixtures of a choline salt (chloride or acetate form) and glycerol are prepared as easily accessible, biodegradable, and inexpensive alternatives to conventional aprotic cation-anion paired ionic liquids. These DES systems display excellent fluidity coupled with thermal stability to nearly 200 °C. In this work, the transesterification activities of cross-linked proteases (subtilisin and α-chymotrypsin), immobilized on chitosan, were individually exa...

  7. An Investigation of the Behavior of Solvent based Polycaprolactone ink for Material Jetting.

    Science.gov (United States)

    He, Yinfeng; Wildman, Ricky D; Tuck, Chris J; Christie, Steven D R; Edmondson, Steven

    2016-02-12

    An initial study of processing bioresorbable polycaprolactone (PCL) through material jetting was conducted using a Fujifilm Dimatix DMP-2830 material printer. The aim of this work was to investigate a potential solvent based method of jetting polycaprolactone. Several solvents were used to prepare a PCL solvent based ink and 1, 4-dioxane was chosen with the consideration of both solubility and safety. The morphology of PCL formed under different substrate temperatures, droplet spacings were investigated. Multi-layer PCL structures were printed and characterized. This work shows that biodegradable polycaprolactone can be processed through material jetting.

  8. An Investigation of the Behavior of Solvent based Polycaprolactone ink for Material Jetting

    Science.gov (United States)

    He, Yinfeng; Wildman, Ricky D.; Tuck, Chris J.; Christie, Steven D. R.; Edmondson, Steven

    2016-02-01

    An initial study of processing bioresorbable polycaprolactone (PCL) through material jetting was conducted using a Fujifilm Dimatix DMP-2830 material printer. The aim of this work was to investigate a potential solvent based method of jetting polycaprolactone. Several solvents were used to prepare a PCL solvent based ink and 1, 4-dioxane was chosen with the consideration of both solubility and safety. The morphology of PCL formed under different substrate temperatures, droplet spacings were investigated. Multi-layer PCL structures were printed and characterized. This work shows that biodegradable polycaprolactone can be processed through material jetting.

  9. Enzymatic selective synthesis of 1,3-DAG based on deep eutectic solvent acting as substrate and solvent.

    Science.gov (United States)

    Zeng, Chao-Xi; Qi, Sui-Jian; Xin, Rui-Pu; Yang, Bo; Wang, Yong-Hua

    2015-11-01

    In this study, enzymatic selective esterification of oleic acid with glycerol based on deep eutectic solvent acting as substrate and solvent was studied. As choline chloride (ChCl) or betaine can effectively change the chemical reaction characteristics of glycerol when they are mixed with a certain molar ratio of glycerol, several factors crucial to the lipase catalytic esterification of glycerol with oleic acid was investigated. Results showed that, betaine had more moderate effects than ChCl on the lipase, and water content had an important influence of the esterification and the enzyme selectivity. Significant changes of the glyceride compositions and enzyme selectivity were found in ChCl adding system compared with pure glycerol system; optimum accumulation of DAG especially 1,3-DAG because of the eutectic effect of ChCl was found in this system. Furthermore, in a model 1,3-DAG esterification synthesis system catalyzed by Novozym 435, high content (42.9 mol%) of the 1,3-DAG could be obtained in ChCl adding system within 1 h. PMID:26210852

  10. Knowledge based system for runtime controlling of multiscale model of ion-exchange solvent extraction

    Science.gov (United States)

    Macioł, Piotr; Gotfryd, Leszek; Macioł, Andrzej

    2012-09-01

    The hereby paper concerns the issue of solution of runtime controlling of multiscale model of ion-exchange solvent extraction. It is based on cooperation of a framework applying Agile Multiscale Modeling Methodology (AM3), and the REBIT Knowledge Based System. Ion-exchange solvent extraction has been shortly introduced. Design assumptions of AM3 and theoretical basis of REBIT have been described. Designed workflows and rules for simple laminar/ turbulent flow and extraction processes have been shown.

  11. Molecular-Based Theory for Electron-Transfer Reorganization Energy in Solvent Mixtures.

    Science.gov (United States)

    Zhuang, Bilin; Wang, Zhen-Gang

    2016-07-01

    Using statistical-field techniques, we develop a molecular-based dipolar self-consistent-field theory (DSCFT) for charge solvation in liquid mixtures under equilibrium and nonequilibrium conditions, and apply it to compute the solvent reorganization energy of electron-transfer reactions. In addition to the nonequilibrium orientational polarization, the reorganization energy in liquid mixtures is also determined by the out-of-equilibrium solvent composition around the reacting species due to preferential solvation. Using molecular parameters that are readily available, the DSCFT naturally accounts for the dielectric saturation effect and the spatially varying solvent composition in the vicinity of the reacting species. We identify three general categories of binary solvent mixtures, classified by the relative optical and static dielectric permittivities of the solvent components. Each category of mixture is shown to produce a characteristic local solvent composition profile in the vicinity of the reacting species, which gives rise to the distinctive composition dependence of the reorganization energy that cannot be predicted using the dielectric permittivities of the homogeneous solvent mixtures. PMID:27187110

  12. Protease activation in glycerol-based deep eutectic solvents

    Science.gov (United States)

    Zhao, Hua; Baker, Gary A.; Holmes, Shaletha

    2011-01-01

    Deep eutectic solvents (DESs) consisting of mixtures of a choline salt (chloride or acetate form) and glycerol are prepared as easily accessible, biodegradable, and inexpensive alternatives to conventional aprotic cation-anion paired ionic liquids. These DES systems display excellent fluidity coupled with thermal stability to nearly 200 °C. In this work, the transesterification activities of cross-linked proteases (subtilisin and α-chymotrypsin), immobilized on chitosan, were individually examined in these novel DESs. In the 1:2 molar ratio mixture of choline chloride/glycerol containing 3% (v/v) water, cross-linked subtilisin exhibited an excellent activity (2.9 μmo l min−1 g−1) in conjunction with a selectivity of 98% in the transesterification reaction of N-acetyl-L-phenylalanine ethyl ester with 1-propanol. These highly encouraging results advocate more extensive exploration of DESs in protease-mediated biotransformations of additional polar substrates and use of DESs in biocatalysis more generally. PMID:21909232

  13. Synergetic Solvent Engineering of Film Nanomorphology to Enhance Planar Perylene Diimide-Based Organic Photovoltaics.

    Science.gov (United States)

    Wang, Jialin; Liang, Ziqi

    2016-08-31

    Solvent additive has proven as a useful protocol for improving the film nanomorphology of polymer donor (D): fullerene acceptor (A) blends in bulk heterojunction (BHJ) photovoltaic cells. By contrast, the effect of such solvent additive on nonfullerene BHJ cells based on perylene diimide acceptor, for instance, is less effective because of their highly planar structure and strong π-aggregation in solid state. Here we choose N,N'-bis(1-ethylpropyl)-perylene-3,4,9,10-tetracarboxylic diimide (PDI) and thieno[3,4-b]thiophene-alt-benzodithiophene (PTB7) as a model D:A blend system to investigate how solvent engineering strategy synergistically impacts the blend film nanomorphology. Based on the differences of solvent volatility and solubility, various host solvents-chloroform (CF) and chlorobenzene (CB) and solvent additives-chloronaphthalene (CN) and 1,8-diiodooctane (DIO) are selected for comparative studies. It is found that the π-aggregation of PDIs can be largely suppressed by using low-boiling point (Tb) CF solvent, yet enlarged by using high-Tb CB. Moreover, CN additive provides good solubility of PDI molecules and hence reduces large PDI aggregates in CB system, while DIO exhibiting poor solubility works oppositely. By contrast, DIO that presents larger Tb difference with CF prolongs the film-forming, which assists in optimizing the PDI aggregation and increases the intermixed PTB7:PDI phases more significantly than CN in CF system, yielding the finest phase-separation morphology and balanced charge mobility. Consequently, the inverted BHJ cells based on CF-processed PTB7:PDI blend film with 0.4 vol % DIO exhibit the highest PCE of 3.55% with a fill factor of 56%, both of which are among the best performance for such a paradigm PTB7:PDI blend-based BHJ cells.

  14. Synergetic Solvent Engineering of Film Nanomorphology to Enhance Planar Perylene Diimide-Based Organic Photovoltaics.

    Science.gov (United States)

    Wang, Jialin; Liang, Ziqi

    2016-08-31

    Solvent additive has proven as a useful protocol for improving the film nanomorphology of polymer donor (D): fullerene acceptor (A) blends in bulk heterojunction (BHJ) photovoltaic cells. By contrast, the effect of such solvent additive on nonfullerene BHJ cells based on perylene diimide acceptor, for instance, is less effective because of their highly planar structure and strong π-aggregation in solid state. Here we choose N,N'-bis(1-ethylpropyl)-perylene-3,4,9,10-tetracarboxylic diimide (PDI) and thieno[3,4-b]thiophene-alt-benzodithiophene (PTB7) as a model D:A blend system to investigate how solvent engineering strategy synergistically impacts the blend film nanomorphology. Based on the differences of solvent volatility and solubility, various host solvents-chloroform (CF) and chlorobenzene (CB) and solvent additives-chloronaphthalene (CN) and 1,8-diiodooctane (DIO) are selected for comparative studies. It is found that the π-aggregation of PDIs can be largely suppressed by using low-boiling point (Tb) CF solvent, yet enlarged by using high-Tb CB. Moreover, CN additive provides good solubility of PDI molecules and hence reduces large PDI aggregates in CB system, while DIO exhibiting poor solubility works oppositely. By contrast, DIO that presents larger Tb difference with CF prolongs the film-forming, which assists in optimizing the PDI aggregation and increases the intermixed PTB7:PDI phases more significantly than CN in CF system, yielding the finest phase-separation morphology and balanced charge mobility. Consequently, the inverted BHJ cells based on CF-processed PTB7:PDI blend film with 0.4 vol % DIO exhibit the highest PCE of 3.55% with a fill factor of 56%, both of which are among the best performance for such a paradigm PTB7:PDI blend-based BHJ cells. PMID:27513281

  15. Conceptual design of a novel CO2 capture process based on precipitating amino acid solvents

    NARCIS (Netherlands)

    Sanchez Fernandez, E.; Heffernan, K.; Ham, L.V. van der; Linders, M.J.G.; Eggink, E.; Schrama, F.N.H.; Brilman, D.W.F.; Goetheer, E.L.V.; Vlugt, T.J.H.

    2013-01-01

    Amino acid salt based solvents can be used for CO2 removal from flue gas in a conventional absorption-thermal desorption process. Recently, new process concepts have been developed based on the precipitation of the amino acid zwitterion species during the absorption of CO2. In this work, a new conce

  16. Thermodynamically based solvent design for enzymatic saccharide acylation with hydroxycinnamic acids in non-conventional media.

    Science.gov (United States)

    Zeuner, Birgitte; Kontogeorgis, Georgios M; Riisager, Anders; Meyer, Anne S

    2012-02-15

    Enzyme-catalyzed synthesis has been widely studied with lipases (EC 3.1.1.3), but feruloyl esterases (FAEs; EC 3.1.1.73) may provide advantages such as higher substrate affinity and regioselectivity in the synthesis of hydroxycinnamate saccharide esters. These compounds are interesting because of their amphiphilicity and antioxidative potential. Synthetic reactions using mono- or disaccharides as one of the substrates may moreover direct new routes for biomass upgrading in the biorefinery. The paper reviews the available data for enzymatic hydroxycinnamate saccharide ester synthesis in organic solvent systems as well as other enzymatic hydroxycinnamate acylations in ionic liquid systems. The choice of solvent system is highly decisive for enzyme stability, selectivity, and reaction yields in these synthesis reactions. To increase the understanding of the reaction environment and to facilitate solvent screening as a crucial part of the reaction design, the review explores the use of activity coefficient models for describing these systems and - more importantly - the use of group contribution model UNIFAC and quantum chemistry based COSMO-RS for thermodynamic predictions and preliminary solvent screening. Surfactant-free microemulsions of a hydrocarbon, a polar alcohol, and water are interesting solvent systems because they accommodate different substrate and product solubilities and maintain enzyme stability. Ionic liquids may provide advantages as solvents in terms of increased substrate and product solubility, higher reactivity and selectivity, as well as tunable physicochemical properties, but their design should be carefully considered in relation to enzyme stability. The treatise shows that thermodynamic modeling tools for solvent design provide a new toolbox to design enzyme-catalyzed synthetic reactions from biomass sources. PMID:22154740

  17. Multifunctional membranes for solvent resistant nanofiltration and pervaporation applications based on segmented polymer networks.

    Science.gov (United States)

    Li, Xianfeng; Basko, Malgorzata; Du Prez, S Filip; Vankelecom, Ivo F J

    2008-12-25

    Hydrophilic bis(acrylate)-terminated poly(ethylene oxide) was used as macromolecular cross-linker of different hydrophobic polyacrylates for the synthesis of amphiphilic segmented polymer networks (SPNs). Multifunctional composite membranes with thin SPN toplayers were prepared by in situ polymerization. As the support consisted of hydrolyzed polyacrylonitrile, the high chemical resistance of the composite membrane allowed applications of the SPN-based membranes in solvent-resistant nanofiltration (SRNF) and pervaporation (PV). The membranes show very high retention on Rose Bengal (RB) in different solvents, especially in strong swelling solvents such as tetrahydrofuran (THF) and dimethylformamide (DMF). The membranes were also tested in pervaporation for dehydration of ethanol and isopropanol (IPA). The selectivity of the membranes greatly depends on the composition or the ratio of the hydrophilic and hydrophobic phases of the SPN. PMID:19055387

  18. A simple method for determining water content in organic solvents based on cobalt(II) complexes

    Institute of Scientific and Technical Information of China (English)

    Lin Zhou; Xiao Hua Liu; Hai Xin Bai; Hong Juan Wang

    2011-01-01

    A method to determine water content in organic solvents was developed based on the color change of cobalt(II) nitrate in different solvents. The color-change mechanism and optimal conditions for determining the water content were investigated. The results showed that there was a good linear relationships between the absorbance of cobalt(II) complexes in organic solvents and water contents with y in 0.9989~0.9994. This method has the advantages of low cost, good reproducibility, good sensitivity, simple in operation, fast in detection, friendly to the environment and no limitation on linear range for determining water content. It was used to determine water in samples with a satisfactory recovery in 97.81%~101.24%.

  19. Phosphoric-based ionic liquids as solvents to separate the azeotropic mixture of ethanol and hexane

    International Nuclear Information System (INIS)

    Graphical abstract: Potential solvent for the separation of ethanol and hexane in (liquid + liquid) extraction. - Highlights: • Phosphoric-based ILs were studied as solvents to extract ethanol from hexane. • LLE data for ternary systems with miscibility gap were presented. • The NRTL model can correlate the experimental LLE data with a good accuracy. • [MMIM][DMP] was a promising solvent for the separation of ethanol and hexane. - Abstract: Ethanol and hexane mixtures are present in industrial processes producing oxygenated additives for unleaded gasoline. The separation of ethanol and hexane is important but challenging due to the formation of an azeotropic mixture. This research focuses on the study of phosphoric-based ionic liquids (ILs) as green solvents for the separation of ethanol from hexane in a liquid extraction process. The knowledge of the (liquid + liquid) equilibrium (LLE) of this mixture is essential for the design of the extraction separation technique. Hence, the experimental determination of the LLE data for the ternary system {ethanol + hexane + 1,3-dimethylimidazolium dimethylphosphate ([MMIM][DMP])}, {ethanol + hexane + 1-ethyl-3-methylimidazolium diethylphosphate ([EMIM][DEP])} and {ethanol + hexane + 1-butyl-3-methylimidazolium dibutylphosphate ([BMIM][DBP])} at T = 303.2 K and atmospheric pressure was carried out. The reliability of the experimental LLE data was confirmed by applying the Othmer–Tobias and Hand equations, and the NRTL model was used to correlate the experimental results for the studied ternary system. The solute distribution ratio and selectivity, derived from the experimental LLE data, were calculated and analyzed evaluate the capacity of the investigated ILs as solvents in liquid extraction process. This capacity was also compared with that of other ILs. The experimental results show that the studied ILs can be suitable solvents in a (liquid + liquid) extraction for the separation of azeotropic mixtures of ethanol

  20. Alcohol based-deep eutectic solvent (DES) as an alternative green additive to increase rotenone yield

    International Nuclear Information System (INIS)

    Deep eutectic solvents (DESs) are basically molten salts that interact by forming hydrogen bonds between two added components at a ratio where eutectic point reaches a melting point lower than that of each individual component. Their remarkable physicochemical properties (similar to ionic liquids) with remarkable green properties, low cost and easy handling make them a growing interest in many fields of research. Therefore, the objective of pursuing this study is to analyze the potential of alcohol-based DES as an extraction medium for rotenone extraction from Derris elliptica roots. DES was prepared by a combination of choline chloride, ChCl and 1, 4-butanediol at a ratio of 1/5. The structure of elucidation of DES was analyzed using FTIR, 1H-NMR and 13C-NMR. Normal soaking extraction (NSE) method was carried out for 14 hours using seven different types of solvent systems of (1) acetone; (2) methanol; (3) acetonitrile; (4) DES; (5) DES + methanol; (6) DES + acetonitrile; and (7) [BMIM] OTf + acetone. Next, the yield of rotenone, % (w/w), and its concentration (mg/ml) in dried roots were quantitatively determined by means of RP-HPLC. The results showed that a binary solvent system of [BMIM] OTf + acetone and DES + acetonitrile was the best solvent system combination as compared to other solvent systems. It contributed to the highest rotenone content of 0.84 ± 0.05% (w/w) (1.09 ± 0.06 mg/ml) and 0.84 ± 0.02% (w/w) (1.03 ± 0.01 mg/ml) after 14 hours of exhaustive extraction time. In conclusion, a combination of the DES with a selective organic solvent has been proven to have a similar potential and efficiency as of ILs in extracting bioactive constituents in the phytochemical extraction process

  1. Alcohol based-deep eutectic solvent (DES) as an alternative green additive to increase rotenone yield

    Energy Technology Data Exchange (ETDEWEB)

    Othman, Zetty Shafiqa; Hassan, Nur Hasyareeda; Zubairi, Saiful Irwan [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia (UKM), 43600 Bangi, Selangor (Malaysia)

    2015-09-25

    Deep eutectic solvents (DESs) are basically molten salts that interact by forming hydrogen bonds between two added components at a ratio where eutectic point reaches a melting point lower than that of each individual component. Their remarkable physicochemical properties (similar to ionic liquids) with remarkable green properties, low cost and easy handling make them a growing interest in many fields of research. Therefore, the objective of pursuing this study is to analyze the potential of alcohol-based DES as an extraction medium for rotenone extraction from Derris elliptica roots. DES was prepared by a combination of choline chloride, ChCl and 1, 4-butanediol at a ratio of 1/5. The structure of elucidation of DES was analyzed using FTIR, {sup 1}H-NMR and {sup 13}C-NMR. Normal soaking extraction (NSE) method was carried out for 14 hours using seven different types of solvent systems of (1) acetone; (2) methanol; (3) acetonitrile; (4) DES; (5) DES + methanol; (6) DES + acetonitrile; and (7) [BMIM] OTf + acetone. Next, the yield of rotenone, % (w/w), and its concentration (mg/ml) in dried roots were quantitatively determined by means of RP-HPLC. The results showed that a binary solvent system of [BMIM] OTf + acetone and DES + acetonitrile was the best solvent system combination as compared to other solvent systems. It contributed to the highest rotenone content of 0.84 ± 0.05% (w/w) (1.09 ± 0.06 mg/ml) and 0.84 ± 0.02% (w/w) (1.03 ± 0.01 mg/ml) after 14 hours of exhaustive extraction time. In conclusion, a combination of the DES with a selective organic solvent has been proven to have a similar potential and efficiency as of ILs in extracting bioactive constituents in the phytochemical extraction process.

  2. Alcohol based-deep eutectic solvent (DES) as an alternative green additive to increase rotenone yield

    Science.gov (United States)

    Othman, Zetty Shafiqa; Hassan, Nur Hasyareeda; Zubairi, Saiful Irwan

    2015-09-01

    Deep eutectic solvents (DESs) are basically molten salts that interact by forming hydrogen bonds between two added components at a ratio where eutectic point reaches a melting point lower than that of each individual component. Their remarkable physicochemical properties (similar to ionic liquids) with remarkable green properties, low cost and easy handling make them a growing interest in many fields of research. Therefore, the objective of pursuing this study is to analyze the potential of alcohol-based DES as an extraction medium for rotenone extraction from Derris elliptica roots. DES was prepared by a combination of choline chloride, ChCl and 1, 4-butanediol at a ratio of 1/5. The structure of elucidation of DES was analyzed using FTIR, 1H-NMR and 13C-NMR. Normal soaking extraction (NSE) method was carried out for 14 hours using seven different types of solvent systems of (1) acetone; (2) methanol; (3) acetonitrile; (4) DES; (5) DES + methanol; (6) DES + acetonitrile; and (7) [BMIM] OTf + acetone. Next, the yield of rotenone, % (w/w), and its concentration (mg/ml) in dried roots were quantitatively determined by means of RP-HPLC. The results showed that a binary solvent system of [BMIM] OTf + acetone and DES + acetonitrile was the best solvent system combination as compared to other solvent systems. It contributed to the highest rotenone content of 0.84 ± 0.05% (w/w) (1.09 ± 0.06 mg/ml) and 0.84 ± 0.02% (w/w) (1.03 ± 0.01 mg/ml) after 14 hours of exhaustive extraction time. In conclusion, a combination of the DES with a selective organic solvent has been proven to have a similar potential and efficiency as of ILs in extracting bioactive constituents in the phytochemical extraction process.

  3. Temporal variation of VOC emission from solvent and water based wood stains

    Science.gov (United States)

    de Gennaro, Gianluigi; Loiotile, Annamaria Demarinis; Fracchiolla, Roberta; Palmisani, Jolanda; Saracino, Maria Rosaria; Tutino, Maria

    2015-08-01

    Solvent- and water-based wood stains were monitored using a small test emission chamber in order to characterize their emission profiles in terms of Total and individual VOCs. The study of concentration-time profiles of individual VOCs enabled to identify the compounds emitted at higher concentration for each type of stain, to examine their decay curve and finally to estimate the concentration in a reference room. The solvent-based wood stain was characterized by the highest Total VOCs emission level (5.7 mg/m3) that decreased over time more slowly than those related to water-based ones. The same finding was observed for the main detected compounds: Benzene, Toluene, Ethylbenzene, Xylenes, Styrene, alpha-Pinene and Camphene. On the other hand, the highest level of Limonene was emitted by a water-based wood stain. However, the concentration-time profile showed that water-based product was characterized by a remarkable reduction of the time of maximum and minimum emission: Limonene concentration reached the minimum concentration in about half the time compared to the solvent-based product. According to AgBB evaluation scheme, only one of the investigated water-based wood stains can be classified as a low-emitting product whose use may not determine any potential adverse effect on human health.

  4. A green deep eutectic solvent-based aqueous two-phase system for protein extracting

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Kaijia; Wang, Yuzhi, E-mail: wyzss@hnu.edu.cn; Huang, Yanhua; Li, Na; Wen, Qian

    2015-03-15

    Highlights: • A strategy for the protein purification with a deep eutectic solvent(DES)-based aqueous two-phase system. • Choline chloride-glycerin DES was selected as the extraction solvent. • Bovine serum albumin and trypsin were used as the analytes. • Aggregation phenomenon was detected in the mechanism research. - Abstract: As a new type of green solvent, deep eutectic solvent (DES) has been applied for the extraction of proteins with an aqueous two-phase system (ATPS) in this work. Four kinds of choline chloride (ChCl)-based DESs were synthesized to extract bovine serum albumin (BSA), and ChCl-glycerol was selected as the suitable extraction solvent. Single factor experiments have been done to investigate the effects of the extraction process, including the amount of DES, the concentration of salt, the mass of protein, the shaking time, the temperature and PH value. Experimental results show 98.16% of the BSA could be extracted into the DES-rich phase in a single-step extraction under the optimized conditions. A high extraction efficiency of 94.36% was achieved, while the conditions were applied to the extraction of trypsin (Try). Precision, repeatability and stability experiments were studied and the relative standard deviations (RSD) of the extraction efficiency were 0.4246% (n = 3), 1.6057% (n = 3) and 1.6132% (n = 3), respectively. Conformation of BSA was not changed during the extraction process according to the investigation of UV–vis spectra, FT-IR spectra and CD spectra of BSA. The conductivity, dynamic light scattering (DLS) and transmission electron microscopy (TEM) were used to explore the mechanism of the extraction. It turned out that the formation of DES–protein aggregates play a significant role in the separation process. All the results suggest that ChCl-based DES-ATPS are supposed to have the potential to provide new possibilities in the separation of proteins.

  5. Supramolecular solvent-based vortex-mixed microextraction: determination of glucocorticoids in water samples.

    Science.gov (United States)

    Qin, Hui; Qiu, Xiaoyan; Zhao, Jiao; Liu, Mousheng; Yang, Yaling

    2013-10-11

    Glucocorticoids contamination has become a big environmental issue in China and other developing countries, due to increasing needs in medical prescription and farming. However, no highly sensitive and precise methods have been reported to quantify glucocorticoids so far. In the past several years, supramolecular solvent-based vortex-mixed microextraction (SS-BVMME) has been shown to be effective. However, the mechanism of SS-BVMME is still unknown. In this report, a novel method has been proposed for rapid quantification of trace amount of glucocorticoids, beclomethasone dipropionate (BD), hydrocortisone butyrate (HB) and nandrolone phenylpropionate (NPP) in water samples from the Green Lake. This method is simple, safe and cost effective. It contains two steps: supramolecular solvent-based vortex-mixed microextraction (SS-BVMME) technique and high performance liquid chromatography (HPLC) analysis. First, ionic liquids 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM]BF4) and n-butanol were mixed to form the supramolecular solvent. After mixing the supramolecular solvent with an aqueous sample to test, a homogenous mixture was formed immediately. BD, HB and NPP were then extracted based on their binding interactions, particularly hydrogen bond formed between their hydroxyl group and the supramolecular solvent. The overall process of sample preparation took only 20min and more than 5 samples could be simultaneously prepared. The minimum detectable concentrations of samples in this method were 0.09925, 0.5429 and 2.428ngmL(-1) for BD, HB and NPP, respectively. Product recoveries ranged from 88% to 103% with relative standard deviations from 0.6% to 4%. For the first time, we report that hydrogen bond plays a key role in SS-BVMME. We also improve the sensitivity significantly to quantify glucocorticoids, which may greatly benefit environmental safety management in China.

  6. A green deep eutectic solvent-based aqueous two-phase system for protein extracting

    International Nuclear Information System (INIS)

    Highlights: • A strategy for the protein purification with a deep eutectic solvent(DES)-based aqueous two-phase system. • Choline chloride-glycerin DES was selected as the extraction solvent. • Bovine serum albumin and trypsin were used as the analytes. • Aggregation phenomenon was detected in the mechanism research. - Abstract: As a new type of green solvent, deep eutectic solvent (DES) has been applied for the extraction of proteins with an aqueous two-phase system (ATPS) in this work. Four kinds of choline chloride (ChCl)-based DESs were synthesized to extract bovine serum albumin (BSA), and ChCl-glycerol was selected as the suitable extraction solvent. Single factor experiments have been done to investigate the effects of the extraction process, including the amount of DES, the concentration of salt, the mass of protein, the shaking time, the temperature and PH value. Experimental results show 98.16% of the BSA could be extracted into the DES-rich phase in a single-step extraction under the optimized conditions. A high extraction efficiency of 94.36% was achieved, while the conditions were applied to the extraction of trypsin (Try). Precision, repeatability and stability experiments were studied and the relative standard deviations (RSD) of the extraction efficiency were 0.4246% (n = 3), 1.6057% (n = 3) and 1.6132% (n = 3), respectively. Conformation of BSA was not changed during the extraction process according to the investigation of UV–vis spectra, FT-IR spectra and CD spectra of BSA. The conductivity, dynamic light scattering (DLS) and transmission electron microscopy (TEM) were used to explore the mechanism of the extraction. It turned out that the formation of DES–protein aggregates play a significant role in the separation process. All the results suggest that ChCl-based DES-ATPS are supposed to have the potential to provide new possibilities in the separation of proteins

  7. Estudio de las Propiedades Anticorrosivas del Benzoato de Hierro (III en Pinturas Base Solvente Study of Anticorrosive Properties of the Iron (III Benzoate in Solvent Based Paints

    Directory of Open Access Journals (Sweden)

    Guillermo Blustein

    2006-01-01

    Full Text Available La acción inhibidora del benzoato de hierro en electrodos de acero SAE 1010 en contacto con una suspensión acuosa fue estudiada mediante ensayos electroquímicos. Paralelamente, la eficiencia anticorrosiva de este producto incorporado a cubiertas orgánicas base solvente fue evaluada mediante ensayos de envejecimiento acelerado (cámara de niebla salina y de humedad. La evolución del comportamiento protector de la cubierta aplicada sobre paneles de acero pintados e inmersos en una solución 0.5M de NaClO4 fue periódicamente monitoreada por espectroscopía de impedancia electroquímica. Los resultados obtenidos indican que las pinturas formuladas con benzoato férrico presentan una capacidad anticorrosiva comparable a las formuladas con fosfato de cinc.This study investigated the inhibitory action of iron benzoate on SAE 1010 steel electrodes in aqueous suspensions using electrochemical assays. The anticorrosive efficiency of this product added to organic solvent-based coatings was also evaluated by means of accelerated weathering tests (salt spray cabinet and humidity chamber. The evolution of the protective behavior of the coating applied on steel panels and immersed in 0.5M NaClO4 solution was periodically checked by electrochemical impedance spectroscopy. The results obtained showed that paints formulated with ferric benzoate provide anticorrosive protection similar to those formulated with zinc phosphate.

  8. Bridge- and Solvent-Mediated Intramolecular Electronic Communications in Ubiquinone-Based Biomolecular Wires

    Science.gov (United States)

    Liu, Xiao-Yuan; Ma, Wei; Zhou, Hao; Cao, Xiao-Ming; Long, Yi-Tao

    2015-05-01

    Intramolecular electronic communications of molecular wires play a crucial role for developing molecular devices. In the present work, we describe different degrees of intramolecular electronic communications in the redox processes of three ubiquinone-based biomolecular wires (Bis-CoQ0s) evaluated by electrochemistry and Density Functional Theory (DFT) methods in different solvents. We found that the bridges linkers have a significant effect on the electronic communications between the two peripheral ubiquinone moieties and solvents effects are limited and mostly depend on the nature of solvents. The DFT calculations for the first time indicate the intensity of the electronic communications during the redox processes rely on the molecular orbital elements VL for electron transfer (half of the energy splitting of the LUMO and LUMO+1), which is could be affected by the bridges linkers. The DFT calculations also demonstrates the effect of solvents on the latter two-electron transfer of Bis-CoQ0s is more significant than the former two electrons transfer as the observed electrochemical behaviors of three Bis-CoQ0s. In addition, the electrochemistry and theoretical calculations reveal the intramolecular electronic communications vary in the four-electron redox processes of three Bis-CoQ0s.

  9. Bridge- and Solvent-Mediated Intramolecular Electronic Communications in Ubiquinone-Based Biomolecular Wires

    OpenAIRE

    Liu, Xiao-Yuan; Ma, Wei; Zhou, Hao; Cao, Xiao-Ming; Long, Yi-Tao

    2015-01-01

    Intramolecular electronic communications of molecular wires play a crucial role for developing molecular devices. In the present work, we describe different degrees of intramolecular electronic communications in the redox processes of three ubiquinone-based biomolecular wires (Bis-CoQ0s) evaluated by electrochemistry and Density Functional Theory (DFT) methods in different solvents. We found that the bridges linkers have a significant effect on the electronic communications between the two pe...

  10. Solvent-based self-healing approaches for fiber-reinforced composites

    Science.gov (United States)

    Jones, Amanda R.

    Damage in composite materials spans many length scales and is often difficult to detect or costly to repair. The incorporation of self-healing functionality in composite materials has the potential to greatly extend material lifetime and reliability. Although there has been remarkable progress in self-healing polymers over the past decade, self-repair in fiber-reinforced composite materials presents significant technical challenges due to stringent manufacturing and performance requirements. For high performance, fiber-reinforced composites, the self-healing components need to survive high temperature processing, reside in matrix interstitial regions to retain a high fiber volume fraction, and have minimal impact on the mechanical properties of the host material. This dissertation explores several microencapsulated solvent-based self-healing approaches for fiber-reinforced composites at the fiber/ matrix interface size scale as well as matrix cracking. Systems are initially developed for room temperature cured epoxies/ glass fiber interfaces and successfully transitioned to carbon fibers and high temperature-cured, thermoplastic-toughened matrices. Full recovery of interfacial bond strength after complete fiber/matrix debonding is achieved with a microencapsulated solvent-based healing chemistry. The surface of a glass fiber is functionalized with microcapsules containing varying concentrations of reactive epoxy resin and ethyl phenyl acetate (EPA) solvent. Microbond specimens consisting of a single fiber and a microdroplet of epoxy are cured at 35°C, tested, and the interfacial shear strengths (IFSS) during the initial (virgin) debonding and subsequent healing events are measured. Debonding of the fiber/matrix interface ruptures the capsules, releasing resin and solvent into the crack plane. The solvent swells the matrix, initiating transport of residual amine functionality for further curing with the epoxy resin delivered to the crack plane. Using a resin-solvent

  11. Solvent wash solution

    Science.gov (United States)

    Neace, James C.

    1986-01-01

    Process for removing diluent degradation products from a solvent extraction solution, which has been used to recover uranium and plutonium from spent nuclear fuel. A wash solution and the solvent extraction solution are combined. The wash solution contains (a) water and (b) up to about, and including, 50 volume percent of at least one-polar water-miscible organic solvent based on the total volume of the water and the highly-polar organic solvent. The wash solution also preferably contains at least one inorganic salt. The diluent degradation products dissolve in the highly-polar organic solvent and the organic solvent extraction solvent do not dissolve in the highly-polar organic solvent. The highly-polar organic solvent and the extraction solvent are separated.

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

    Science.gov (United States)

    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.

  13. Supercritical CO2-based solvents in next generation micro- electronics processing

    Institute of Scientific and Technical Information of China (English)

    ZHANG XiaoGang; Keith P.JOHNSTON

    2007-01-01

    Large amount of chemicals and highly purified-water are needed in microelectronic manufacture. The ability of solutions to penetrate tiny spaces will become significantly more challenging as the feature size of semiconductor devices decreases to nanoscale dimensions and the functional complexity of integrated circuitries (ICs) ever increases. Supercritical fluids (SCFs) possess a unique combination of properties (no surface tension and gas-like viscosity) that can potentially be exploited for application in microelectronics manufacturing and processing in response to needs for material-compatible cleaning systems, small-dimension developing solvents, and low chemical-use processes. Recent microelectronics processes for cleaning and rinsing of patterned porous low-k dielectrics and drying of photoresist in CO2-based solvents are the main focus of this review. Additional topics in supercritical fluid processing include spin coating of photoresists, development with nanoscale dimensions, metal deposition and silylation.

  14. Dropwise additive manufacturing of pharmaceutical products for solvent-based dosage forms.

    Science.gov (United States)

    Hirshfield, Laura; Giridhar, Arun; Taylor, Lynne S; Harris, Michael T; Reklaitis, Gintaras V

    2014-02-01

    In recent years, the US Food and Drug Administration has encouraged pharmaceutical companies to develop more innovative and efficient manufacturing methods with improved online monitoring and control. Mini-manufacturing of medicine is one such method enabling the creation of individualized product forms for each patient. This work presents dropwise additive manufacturing of pharmaceutical products (DAMPP), an automated, controlled mini-manufacturing method that deposits active pharmaceutical ingredients (APIs) directly onto edible substrates using drop-on-demand (DoD) inkjet printing technology. The use of DoD technology allows for precise control over the material properties, drug solid state form, drop size, and drop dynamics and can be beneficial in the creation of high-potency drug forms, combination drugs with multiple APIs or individualized medicine products tailored to a specific patient. In this work, DAMPP was used to create dosage forms from solvent-based formulations consisting of API, polymer, and solvent carrier. The forms were then analyzed to determine the reproducibility of creating an on-target dosage form, the morphology of the API of the final form and the dissolution behavior of the drug over time. DAMPP is found to be a viable alternative to traditional mass-manufacturing methods for solvent-based oral dosage forms. PMID:24311373

  15. An acetylcholinesterase (AChE) biosensor with enhanced solvent resistance based on chitosan for the detection of pesticides.

    Science.gov (United States)

    Warner, John; Andreescu, Silvana

    2016-01-01

    Solvent tolerance of immobilized enzymes is important for many biosensing and biotechnological applications. In this paper we report an acetylcholinesterase (AChE) biosensor based on chitosan that exhibits high solvent resistance and enables sensitive detection of pesticides in presence of a high content of organic solvents. The solvent effect was established comparatively for the enzyme immobilized in chitosan and covalently cross-linked with glutaraldehyde. The activity of the immobilized AChE was dependent on the immobilization method and solvent type. The enzyme entrapped in chitosan fully conserved its activity in up to 25% methanol, 15% acetonitrile and 100% cyclohexane while the enzyme cross-linked with glutaraldehyde gradually lost its activity starting at 5% acetonitrile and methanol, and showed variable levels in cyclohexane. The detection limits of the biosensor for paraoxon were: 7.5 nM in 25% methanol, 100 nM in 15% acetonitrile and 2.5 μM in 100% cyclohexane. This study demonstrates that chitosan provides an excellent immobilization environment for AChE biosensors designed to operate in environments containing high amounts of organic solvents. It also highlights the effect of the immobilization material and solvent type on enzyme stability. These findings can enable future selection of the immobilization matrix and solvent type for the development of organic phase enzyme based systems.

  16. Solvent Optimization for Efficient Enzymatic Monoacylglycerol Production Based on a Glycerolysis Reaction

    DEFF Research Database (Denmark)

    Damstrup, Marianne; Jensen, Tine; Sparsø, Flemming V.;

    2005-01-01

    This study was aimed at screening solvent systems of varying polarities to identify suitable solvents for efficient and practical enzymatic glycerolysis. Several pure solvents and solvent mixtures were screened in a batch reaction system consisting of glycerol, sunflower oil, and Novozymo (R) 435...

  17. Solvent-free Synthesis of Flavanone over New Hybrid Mesoporous Base Catalysts

    Institute of Scientific and Technical Information of China (English)

    WANG Hui; NIU Xiao-di; ZHAO Min; XIAO Xue-bin; WANG Hong-su; WANG Zhong-dong

    2011-01-01

    Benzyl and anthracenemethyl groups were respectively bonded to the N atoms of 3-aminopropyl functionalized mesoporous SBA-15(APS-SBA-15) to obtain two new base catalysts over which the condensation reaction of benzaldehyde and 2′-hydroxyacetophenone was studied.Good catalytic activities and high selectivities for flavanones were obtained in solvent-free reactions,which is attributed to the effect of benzyl and anthracenemetyl groups on the base sites of catalysts and the steric hindrance of futher reaction of flavanone with benzaldehyde.

  18. Solvent effect on the anharmonic vibrational frequencies in guanine-cytosine base pair

    Science.gov (United States)

    Bende, A.; Muntean, C. M.

    2012-02-01

    We present an ab initio study of the vibrational properties of cytosine and guanine in the Watson-Crick and Hoogsteen base pair configurations. The results are obtained by considering the DFT method together with the Polarizable Continuum Model (PCM) using PBE and B3PW91 exchange-correlation functionals and triple-ζ valence basis set. We investigate the importance of anharmonic corrections for the vibrational modes taking into account the solvent effect of the water environment. In particular, the unusual anharmonic effect of the H+ vibration in the case of the Hoogsteen base pair configuration is discussed.

  19. Efficient inverted organic light-emitting devices by amine-based solvent treatment (Presentation Recording)

    Science.gov (United States)

    Song, Myoung Hoon; Choi, Kyoung-Jin; Jung, Eui Dae

    2015-10-01

    The efficiency of inverted polymer light-emitting diodes (iPLEDs) were remarkably enhanced by introducing spontaneously formed ripple-shaped nanostructure of ZnO (ZnO-R) and amine-based polar solvent treatment using 2-methoxyethanol and ethanolamine (2-ME+EA) co-solvents on ZnO-R. The ripple-shape nanostructure of ZnO layer fabricated by solution process with optimal rate of annealing temperature improves the extraction of wave guide modes inside the device structure, and 2-ME+EA interlayer enhances the electron injection and hole blocking and reduces exciton quenching between polar solvent treated ZnO-R and emissive layer. As a result, our optimized iPLEDs show the luminous efficiency (LE) of 61.6 cd A-1, power efficiency (PE) of 19.4 lm W-1 and external quantum efficiency (EQE) of 17.8 %. This method provides a promising method, and opens new possibilities for not only organic light-emitting diodes (OLEDs) but also other organic optoelectronic devices such as organic photovoltaics, organic thin film transistors, and electrically driven organic diode laser.

  20. Comparison of genetic damage in Brazilian footwear-workers exposed to solvent-based or water-based adhesive.

    Science.gov (United States)

    Heuser, Vanina Dahlström; de Andrade, Vanessa Moraes; da Silva, Juliana; Erdtmann, Bernardo

    2005-05-01

    Research has shown that workers employed in footwear manufacture are at increased risk of some cancers, the strongest evidence being for nasal cancer and leukemia. Footwear-workers are routinely exposed to complex mixtures of solvents in degreasers, cleaners, primers, and adhesives used in the production process as toluene, n-hexane, acetone, and possibly dust particles, additives in shoe materials and degradation products of materials. The recognition of the potential health-hazards of solvent-based adhesives (SBAs) has lead to the development of adhesives with no organic solvents, the water-based adhesives (WBA). We investigated footwear-workers (all males) exposed to SBA (n=29) (for 3.98+/-4.13 years), and WBA (n=16), which had spent the six months previous to the study employed in an experimental section which used only water-based adhesives, although they had previously worked in sections which used solvent-based adhesives (for 5.80+/-4.03 years); 25 healthy subjects were used as controls. The Comet assay and the micronucleus test were used as endpoints, while the traditional parameters for assessing exposure to toluene in organic mixtures by measuring the concentration of urinary hippuric acid were also assessed. Our results showed a significantly lower mean concentration of hippuric acid in the control group than found in the SBA (Pdamage index for the SBA (Pcomparison to the WBA group and control (Pwater-based adhesives are clearly a better option for safeguarding the health of footwear-workers, even with possibility of isocyanate presence, while the positive results observed in SBA group might be explained by chloroprene presence in the adhesive.

  1. Predispersed solvent extraction

    OpenAIRE

    Rodarte, Alma Isabel Marín

    1988-01-01

    A new solvent extraction method has been developed for the extraction of metal and organic ions from very dilute aqueous solutions. The new method, which has been named Predispersed Solvent Extraction (POSE), is based on the principle that 1 there is no need to comminute both phases. All that is necessary is to comminute the solvent phase prior to contacting it with the feed. This is done by converting the solvent into aphrons, which are micron-sized globules encapsulated in a ...

  2. Comparative in vitro study of cholinium-based ionic liquids and deep eutectic solvents toward fish cell line.

    Science.gov (United States)

    Radošević, Kristina; Železnjak, Jelena; Cvjetko Bubalo, Marina; Radojčić Redovniković, Ivana; Slivac, Igor; Gaurina Srček, Višnja

    2016-09-01

    With the advent of ionic liquids, much was expected concerning their applicability as an alternative to organic solvents in the chemical technology and biotechnology fields. However, the most studied and commonly used ionic liquids based on imidazolium and pyridinium were found not to be as environmentally friendly as it was first expected. Therefore, a new generation of alternative solvents named natural ionic liquids and deep eutectic solvents, composed of natural and/or renewable compounds, have come into focus in recent years. Since the number of newly synthesized chemicals increases yearly, simple and reliable methods for their ecotoxicological assessment are necessary. Permanent fish cell lines can serve as a test system for the evaluation of a chemical's cytotoxicity. This paper presents research results on the cytotoxic effects on Channel Catfish Ovary (CCO) cell line induced by fifteen cholinium-based ionic liquids and deep eutectic solvents. Based on the decrease in cell viability, the most obvious toxic effect on CCO cells was caused by ionic liquid choline oxalate, while other solvents tested exhibited low cytotoxicity. Therefore, we can conclude that cholinium-based ionic liquids and deep eutectic solvents are comparatively less toxic to CCO cells than conventional ionic liquids. PMID:27179607

  3. Comparative in vitro study of cholinium-based ionic liquids and deep eutectic solvents toward fish cell line.

    Science.gov (United States)

    Radošević, Kristina; Železnjak, Jelena; Cvjetko Bubalo, Marina; Radojčić Redovniković, Ivana; Slivac, Igor; Gaurina Srček, Višnja

    2016-09-01

    With the advent of ionic liquids, much was expected concerning their applicability as an alternative to organic solvents in the chemical technology and biotechnology fields. However, the most studied and commonly used ionic liquids based on imidazolium and pyridinium were found not to be as environmentally friendly as it was first expected. Therefore, a new generation of alternative solvents named natural ionic liquids and deep eutectic solvents, composed of natural and/or renewable compounds, have come into focus in recent years. Since the number of newly synthesized chemicals increases yearly, simple and reliable methods for their ecotoxicological assessment are necessary. Permanent fish cell lines can serve as a test system for the evaluation of a chemical's cytotoxicity. This paper presents research results on the cytotoxic effects on Channel Catfish Ovary (CCO) cell line induced by fifteen cholinium-based ionic liquids and deep eutectic solvents. Based on the decrease in cell viability, the most obvious toxic effect on CCO cells was caused by ionic liquid choline oxalate, while other solvents tested exhibited low cytotoxicity. Therefore, we can conclude that cholinium-based ionic liquids and deep eutectic solvents are comparatively less toxic to CCO cells than conventional ionic liquids.

  4. Solvent stimulated actuation of polyurethane-based shape memory polymer foams using dimethyl sulfoxide and ethanol

    Science.gov (United States)

    Boyle, A. J.; Weems, A. C.; Hasan, S. M.; Nash, L. D.; Monroe, M. B. B.; Maitland, D. J.

    2016-07-01

    Solvent exposure has been investigated to trigger actuation of shape memory polymers (SMPs) as an alternative to direct heating. This study aimed to investigate the feasibility of using dimethyl sulfoxide (DMSO) and ethanol (EtOH) to stimulate polyurethane-based SMP foam actuation and the required solvent concentrations in water for rapid actuation of hydrophobic SMP foams. SMP foams exhibited decreased T g when submerged in DMSO and EtOH when compared to water submersion. Kinetic DMA experiments showed minimal or no relaxation for all SMP foams in water within 30 min, while SMP foams submerged in EtOH exhibited rapid relaxation within 1 min of submersion. SMP foams expanded rapidly in high concentrations of DMSO and EtOH solutions, where complete recovery over 30 min was observed in DMSO concentrations greater than 90% and in EtOH concentrations greater than 20%. This study demonstrates that both DMSO and EtOH are effective at triggering volume recovery of polyurethane-based SMP foams, including in aqueous environments, and provides promise for use of this actuation technique in various applications.

  5. Gels and lyotropic liquid crystals: using an imidazolium-based catanionic surfactant in binary solvents.

    Science.gov (United States)

    Cheng, Ni; Hu, Qiongzheng; Bi, Yanhui; Xu, Wenwen; Gong, Yanjun; Yu, Li

    2014-08-01

    The self-assembly behavior of an imidazolium-based catanionic surfactant, 1-butyl-3-methylimidazolium dodecylsulfate ([C4mim][C12H25SO4]), was investigated in water-ethylammonium nitrate (EAN) mixed solvents with different volume ratios. It is particular interesting that this simple surfactant could not only form lyotropic liquid crystals (LLC) with multimesophases, i.e., normal hexagonal (H1), lamellar liquid crystal (Lα), and reverse bicontinuous cubic phase (V2), in the water-rich environment but also act as an efficient low-molecular-weight gelator (LMWG) which gelated EAN-abundant binary media in a broad concentration range. The peculiar nanodisk cluster morphology of gels composed of similar bilayer units was first observed. FT-IR spectra and density functional theory (DFT) calculations reveal that strong H bonding and electrostatic interactions between EAN and the headgroups of [C4mim][C12H25SO4] are primarily responsible for gelation. The self-assembled gels displayed excellent mechanical strength and a thermoreversible sol-gel transition. It is for the first time that a rich variety of controllable ordered aggregates could be observed only by simply modulating the concentration of a single imidazolium-based catanionic surfactant or the ratio of mixed solvents. This environmentally friendly system is expected to have broad applications in various fields, such as materials science, drug delivery systems, and supramolecular chemistry.

  6. Extraction of Tetra-oxo Anions into a Hydrophobic, Ionic Liquid-Based Solvent Without Concomitant Ion Exchange

    International Nuclear Information System (INIS)

    Hydrophobic ionic liquids (IL) have the potential to simplify certain separations by serving as both an extraction solvent and an electrolyte for subsequent electrochemical reductions. While IL-based solvents are known to be efficient media for metal ion extraction, separations employing these solvents are frequently complicated by the loss of constituent IL ions to the aqueous phase, resulting in deteriorating performance. In this study, we have examined the extraction of pertechnetate and related tetra-oxo anions from aqueous solutions into IL-based solvents incorporating tetraalkylphosphonium bis((trifluoromethyl)sulfonyl)imide and a crown ether. In contrast to various previously studied IL-based cation extraction systems, facile anion extraction without significant transfer of the IL ions to the aqueous phase has been observed. In addition, the solvents exhibit high distribution ratios (100-500 for pertechnetate), significant electrical conductivity (>100 (micro)S/cm), and a wide (∼4 V) electrochemical window. The results suggest that these solvents may provide the basis for improved approaches to the extraction and recovery of a variety of anions.

  7. A functional natural deep eutectic solvent based on trehalose: Structural and physicochemical properties.

    Science.gov (United States)

    Xin, Ruipu; Qi, Suijian; Zeng, Chaoxi; Khan, Faez Iqbal; Yang, Bo; Wang, Yonghua

    2017-02-15

    In this study, the natural deep eutectic solvents (NADESs) based on trehalose and choline chloride have been prepared to enhance the protein thermostability. The results of fourier transform infrared spectroscopy and (1)H nuclear magnetic resonance spectroscopy suggested that there were intensive hydrogen-bonding interactions between trehalose and choline chloride in TCCL3-DES and TCCL3-DES75. The physicochemical properties of TCCL3-DES and TCCL3-DES75 were investigated in the temperature range of 293.15-363.15K. Our results revealed that the thermostability of lysozyme, a model protein used in this study was dramatically increased in TCCL3-DES75, as evidenced by the disappearance of the denaturing peak from their Differential Scanning Calorimetry (DSC) traces. The results of circular dichroism (CD) experiments further demonstrated that the lysozyme in TCCL3-DES75 unfolded partially at 90°C and recovered to the initial structure at 20°C. The study suggests that TCCL3-DES75 might be a potential solvent for stabilizing proteins. PMID:27664672

  8. Deformation grating fabrication technique based on the solvent-assisted microcontact molding.

    Science.gov (United States)

    Dai, Xianglu; Xie, Huimin; Wang, Huaixi

    2014-10-20

    A deformation grating fabrication technique based on solvent-assisted microcontact molding (SAMIM) is reported in this paper. The fabrication process can be divided into three steps: imprinting a grating on a medium polymer substrate (MPS) by SAMIM, coating a thin metal film on the MPS, and transferring the film to the measured surface. In order to increase the stiffness of the elastic mold without decreasing its conformal contact formation ability, a re-useable, glass-embedded polydimethylsiloxane (PDMS) mold is used. In addition, a characterization method based on the Fourier transform and phase analysis is proposed to check the quality of the fabricated grating. Verified by experiment, the proposed fabrication technique can fabricate a high-frequency large-area grating on different specimens, which can be a qualified deformation sensor for the moiré method. PMID:25402792

  9. Physicochemical properties of ammonium-based deep eutectic solvents and their electrochemical evaluation using organometallic reference redox systems

    International Nuclear Information System (INIS)

    Highlights: • Physicochemical properties of seven deep eutectic solvents as electrolytes measured. • Walden plot showed ideal ammonium-based deep eutectic solvents. • Potential windows of all deep eutectic solvents determined. • Diffusion coefficients and rate constants of organometallic redox couples measured. • Rate constants of deep eutectic solvents were lower than those of ionic liquids. -- Abstract: Seven deep eutectic solvents (DESs) containing ammonium based salts are prepared by means of hydrogen bonding with acid, amine, amide and nitrate based compounds. The major physicochemical properties of the DESs in terms of density, viscosity, electrical conductivity, molar conductivity and pH are investigated prior to ascertaining their electrochemical characteristics by means of cyclic voltammetry and chronoamperometry. Nitrate based DESs exhibit higher conductivities but lower viscosities than other DESs, whereas the amide based DES displays the widest electrochemical potential window. Diffusion coefficient, D, of two organometallic redox couples, Fc/Fc+ (ferrocene/ferrocenium) and Cc/Cc+(cobaltocene/cobaltocenium) is found to be of the order of 10−9 to 10−8 cm2 s−1 in all studied DESs while the heterogeneous rate constant for electron transfer across the electrode/DES interface is of the order of 10−4 cm s−1. The Stokes–Einstein products of Fc and Cc+ in the DESs have also been determined

  10. In Vitro and In Vivo toxicity profiling of ammonium-based deep eutectic solvents.

    Science.gov (United States)

    Hayyan, Maan; Looi, Chung Yeng; Hayyan, Adeeb; Wong, Won Fen; Hashim, Mohd Ali

    2015-01-01

    The cytotoxic potential of ammonium-based deep eutectic solvents (DESs) with four hydrogen bond donors, namely glycerine (Gl), ethylene glycol (EG), triethylene glycol (TEG) and urea (U) were investigated. The toxicity of DESs was examined using In Vitro cell lines and In Vivo animal model. IC50 and selectivity index were determined for the DESs, their individual components and their combinations as aqueous solutions for comparison purposes. The cytotoxicity effect of DESs varied depending on cell lines. The IC50 for the GlDES, EGDES, UDES and TEGDES followed the sequence of TEGDESIn Vivo toxicity profiles of DESs were being demonstrated, raising the toxicity issue of these neoteric mixtures and their potential applicability to be used for therapeutic purposes.

  11. Imidazole-based deep eutectic solvents for starch dissolution and plasticization.

    Science.gov (United States)

    Zdanowicz, Magdalena; Spychaj, Tadeusz; Mąka, Honorata

    2016-04-20

    Potato starch and high-amylose starch were treated with imidazole-based deep eutectic solvents (DESs) as dissolution and plasticization media. Beside imidazole (IM) for two-component DESs preparation choline chloride (CC), glycerol (G) or carboxylic acids (citric or malic) were used. An influence of water content in starch (as well as an extra water in the starch/DES system) on polymer dissolution and plasticization processes was investigated. Dissolution and gelatinization of starch in DESs were followed via DSC and laser scanning microscopy. A rheometric characteristics revealed an influence of starch/DES system storage time on the plasticization process. The tendency to recrystallization of compression-molded-starch films was evaluated using XRD technique. High dissolution and plasticization effectiveness of CC/IM and G/IM and a low tendency to film retrogradation of thermoplasticized starch were noted. PMID:26876869

  12. 1-Butyl-3-Methyl Imidazolium-based Ionic Liquids Explored as Potential Solvents for Lipid Processing

    Science.gov (United States)

    Due to global environmental concerns, there is increasing interest in replacing the volatile solvents currently used to process commodity plant lipids. Room-temperature molten salts are one type of media receiving great attention as a possible replacement of the typical organic solvent. Molten sal...

  13. Develop and test a solvent accessible surface area-based model in conformational entropy calculations.

    Science.gov (United States)

    Wang, Junmei; Hou, Tingjun

    2012-05-25

    It is of great interest in modern drug design to accurately calculate the free energies of protein-ligand or nucleic acid-ligand binding. MM-PBSA (molecular mechanics Poisson-Boltzmann surface area) and MM-GBSA (molecular mechanics generalized Born surface area) have gained popularity in this field. For both methods, the conformational entropy, which is usually calculated through normal-mode analysis (NMA), is needed to calculate the absolute binding free energies. Unfortunately, NMA is computationally demanding and becomes a bottleneck of the MM-PB/GBSA-NMA methods. In this work, we have developed a fast approach to estimate the conformational entropy based upon solvent accessible surface area calculations. In our approach, the conformational entropy of a molecule, S, can be obtained by summing up the contributions of all atoms, no matter they are buried or exposed. Each atom has two types of surface areas, solvent accessible surface area (SAS) and buried SAS (BSAS). The two types of surface areas are weighted to estimate the contribution of an atom to S. Atoms having the same atom type share the same weight and a general parameter k is applied to balance the contributions of the two types of surface areas. This entropy model was parametrized using a large set of small molecules for which their conformational entropies were calculated at the B3LYP/6-31G* level taking the solvent effect into account. The weighted solvent accessible surface area (WSAS) model was extensively evaluated in three tests. For convenience, TS values, the product of temperature T and conformational entropy S, were calculated in those tests. T was always set to 298.15 K through the text. First of all, good correlations were achieved between WSAS TS and NMA TS for 44 protein or nucleic acid systems sampled with molecular dynamics simulations (10 snapshots were collected for postentropy calculations): the mean correlation coefficient squares (R²) was 0.56. As to the 20 complexes, the TS

  14. Steady State and Time-Resolved Fluorescence Dynamics of Triphenylamine Based Oligomers with Phenylene/Thiophene/Furan in Solvents

    Institute of Scientific and Technical Information of China (English)

    ZENG Qi; LIU Ying-Liang; MENG Kang; ZHAO Xiang-Jie; WANG Shu-Feng; GONG Qi-Huang

    2009-01-01

    We investigate the photo-physical properties of a series of triphenylamine-based oligomers by steady-state and picosecond transient fluorescence measurements in solvents. The oligomers are composed alternatively with triph-enylamine and phenylene/thiophene/furan group, bridged by vinyl group (PNB/PNT/PNF). Their fluorescence spectra show bathochromic phenomenon with solvent polarity and viscosity increasing. The fluorescence decays are bi-exponential for PNB and PNT, and tri-exponential for PNF in THF and aniline. The strong viscosity dependence suggests conformational relaxation along the PNF chain after photo excitation.

  15. Characterization of solvents containing CyMe4-BTPhen in selected cyclohexanone-based diluents after irradiation by accelerated electrons

    Directory of Open Access Journals (Sweden)

    Distler Petr

    2015-12-01

    Full Text Available Radiation stability of CyMe4-BTPhen was examined in systems with three selected cyclohexanone-based diluents. Accelerated electrons were used as a source of ionizing radiation. The CyMe4-BTPhen radiation degradation identification and characterization of the degradation products were performed by high performance liquid chromatography (HPLC and mass spectrometry (MS analyses. Residual concentrations of tested ligand were determined. Moreover, extraction properties of the solvents irradiated at two different doses were compared with the extraction properties of non-irradiated solvents to estimate the influence of the presence of degradation products in the organic phase.

  16. RETRACTED: Neoteric FT-IR investigation on the functional groups of phosphonium-based deep eutectic solvents.

    Science.gov (United States)

    Aissaoui, Tayeb; AlNashef, Inas M; Hayyan, Maan; Hashim, Mohd Ali

    2015-10-01

    Deep eutectic solvents (DESs) are novel solvent media that are currently under investigation as an alternative to ionic liquids and conventional solvents. The physical properties of DESs as well as their mild environmental footprint and potentially critical industrial application necessitate understanding the interaction of functional groups on both the salt and hydrogen bond donor (HBD). In this study, four DESs were prepared by mixing triethylenglycol, diethylenglycol, ethylenglycol, and glycerol as HBDs with methyltriphenylphosphonium bromide as a salt at a molar ratio of 1:4. Fourier transform infrared spectroscopy was conducted to highlight the chemical structure and mechanism of the combination of the four DESs. New spectra illustrating the combination of the functional groups of the HBDs and salt were observed and interpreted. This study is the first to investigate the properties of neoteric phosphonium-based DESs. PMID:25985123

  17. Synthesis and thermo-physical properties of deep eutectic solvent-based graphene nanofluids

    Science.gov (United States)

    Fang, Y. K.; Osama, M.; Rashmi, W.; Shahbaz, K.; Khalid, M.; Mjalli, F. S.; Farid, M. M.

    2016-02-01

    This study introduces a new class of heat transfer fluids by dispersing functionalised graphene oxide nanoparticles (GNPs) in ammonium and phosphonium-based deep eutectic solvents (DESs) without the aid of a surfactant. Different molar ratios of salts and hydrogen bond donors (HBD) were used to synthesise DESs for the preparation of different concentrations of graphene nanofluids (GNFs). The concentrations of GNPs were 0.01 wt%, 0.02 wt% and 0.05 wt %. Homogeneous and stable suspensions of nanofluids were obtained by high speed homogenisation and an ultrasonication process. The stability of the GNFs was determined through visual observation for 4 weeks followed by a centrifugal process (5000-20 000 rpm) for 30 min in addition to zeta potential studies. Dispersion of the GNPs in DES was observed using an optical microscope. The synthesised DES-based GNFs showed no particle agglomeration and formation of sediments in the nanofluids. Thermo-physical properties such as thermal conductivity and specific heat of the nanofluids were also investigated in this research. The highest thermal conductivity enhancement of 177% was observed. The findings of this research provide a new class of engineered fluid for heat transfer applications as a function of temperature, type and composition DESs as well as the GNPs concentration.

  18. Process to prepare stable trifluorostyrene containing compounds grafted to base polymers using a solvent/water mixture

    Science.gov (United States)

    Roelofs, Mark Gerrit; Yang, Zhen-Yu; Han, Amy Qi

    2010-06-15

    A fluorinated ion exchange polymer is prepared by grafting at least one grafting monomer derived from trifluorostyrene on to at least one base polymer in a organic solvent/water mixture. These ion exchange polymers are useful in preparing catalyst coated membranes and membrane electrode assemblies used in fuel cells.

  19. Synthesis and Structural Characterization of Magnesium Based Coordination Networks in Different Solvents

    Energy Technology Data Exchange (ETDEWEB)

    Banerjee, Debasis; Finkelstein, Jeffrey; Smirnov, A.; Forster, Paul M.; Borkowski, Lauren A.; Teat, Simon J.; Parise, John B. (LBNL); (UNLV); (Buffalo)

    2015-10-15

    Three magnesium based metal-organic frameworks, Mg{sub 3}(3,5-PDC){sub 3}(DMF){sub 3} {center_dot} DMF [1], Mg(3,5-PDC)(H{sub 2}O) {center_dot} (H{sub 2}O) [3], and Mg4(3,5-PDC)4(DMF){sub 2}(H{sub 2}O){sub 2} {center_dot} 2DMF {center_dot} 4.5H{sub 2}O [4], and a 2-D coordination polymer, [Mg(3,5-PDC)(H{sub 2}O){sub 2}] [2] [PDC = pyridinedicarboxylate], were synthesized using a combination of DMF, methanol, ethanol, and water. Compound 1 [space group P2{sub 1}/n, a = 12.3475(5) {angstrom}, b = 11.1929(5) {angstrom}, c = 28.6734(12) {angstrom}, {beta} = 98.8160(10){sup o}, V = 3916.0(3) {angstrom}{sup 3}] consists of a combination of isolated and corner-sharing magnesium octahedra connected by the organic linkers to form a 3-D network with a 12.2 {angstrom} x 4.6 {angstrom} 1-D channel. The channel contains coordinated and free DMF molecules. In compound 2 [space group C2/c, a = 9.964(5) {angstrom}, b = 12.0694(6) {angstrom}, c = 7.2763(4) {angstrom}, {beta} = 106.4970(6){sup o}, V = 836.70(6) {angstrom}{sup 3}], PDC connects isolated seven coordinated magnesium polyhedra into a layered structure. Compound 3 [space group P6{sub 1}22, a = 11.479(1) {angstrom}, c = 14.735(3) {angstrom}, V = 1681.7(4) {angstrom}{sup 3}] (previously reported) contains isolated magnesium octahedra connected by the organic linker with each other forming a 3D network. Compound 4 [space group P2{sub 1}/c, a = 13.7442(14) {angstrom}, b = 14.2887(15) {angstrom}, c = 14.1178(14) {angstrom}, {beta} = 104.912(2){sup o}, V = 2679.2(5) {angstrom}{sup 3}] also exhibits a 3D network based on isolated magnesium octahedra with square cavities containing both disordered DMF and water molecules. The structural topologies originate due to the variable coordination ability of solvent molecules with the metal center. Water molecules coordinate with the magnesium metal centers preferably over other polar solvents (DMF, methanol, ethanol) used to synthesize the coordination networks. Despite testing

  20. Thermodynamically based solvent design for enzymatic saccharide acylation with hydroxycinnamic acids in non-conventional media

    DEFF Research Database (Denmark)

    Zeuner, Birgitte; Kontogeorgis, Georgios; Riisager, Anders;

    2012-01-01

    Enzyme-catalyzed synthesis has been widely studied with lipases (EC 3.1.1.3), but feruloyl esterases (FAEs; EC 3.1.1.73) may provide advantages such as higher substrate affinity and regioselectivity in the synthesis of hydroxycinnamate saccharide esters. These compounds are interesting because...... as well as other enzymatic hydroxycinnamate acylations in ionic liquid systems. The choice of solvent system is highly decisive for enzyme stability, selectivity, and reaction yields in these synthesis reactions. To increase the understanding of the reaction environment and to facilitate solvent screening......-free microemulsions of a hydrocarbon, a polar alcohol, and water are interesting solvent systems because they accommodate different substrate and product solubilities and maintain enzyme stability. Ionic liquids may provide advantages as solvents in terms of increased substrate and product solubility, higher...

  1. Choline chloride-based deep eutectic solvents as additives for optimizing chromatographic behavior of caffeic acid

    Energy Technology Data Exchange (ETDEWEB)

    Li, Guizhen; Zhu, Tao; Lei, Yingjie [Tianjin University of Technology, Tianjin (China)

    2015-10-15

    A series of deep eutectic solvents (DESs) were prepared using glycerol and choline chloride (ChCl), and Fourier transform infrared spectrometer (FT-IR) was used to analyze the spectra of glycerol, choline chloride and DESs based on glycerol and choline chloride. Then DESs were used as the additives of mobile phase to optimize chromatographic behavior of caffeic acid in high performance liquid chromatography (HPLC). A 17-run Box-Behnken design (BBD) was employed to evaluate effect of DESs as additives by analyzing the maximum theoretical plate number. Three factors, reaction temperature (60 .deg. C, 80 .deg. C, 100 .deg. C), molar ratio of glycerol and choline chloride (2 : 1, 3 : 1, 4 : 1, n/n), and volume percent of additives (0.05%, 0.10%, 0.15%, v/v), were investigated in BBD. The optimum experiment condition was that of reaction temperature (80 .deg. C), molar ratio of glycerol and ChCl (3 : 1, n/n), and volume percent of additive (0.10%, v/v). The mean chromatographic theoretical plate number of the caffeic acid this condition was 1567.5, and DESs as additives shorten the retention time and modify the chromatogram shape, proving DESs as additives for effective theoretical plate number and column efficiency in HPLC.

  2. Toxicity profile of choline chloride-based deep eutectic solvents for fungi and Cyprinus carpio fish.

    Science.gov (United States)

    Juneidi, Ibrahim; Hayyan, Maan; Mohd Ali, Ozair

    2016-04-01

    An investigation on the toxicological assessment of 10 choline chloride (ChCl)-based deep eutectic solvents (DESs) towards four fungi strains and Cyprinus carpio fish was conducted. ChCl was combined with materials from different chemical groups such as alcohols, sugars, acids and others to form DESs. The study was carried out on the individual DES components, their aqueous mixture before DES formation and their formed DESs. The agar disc diffusion method was followed to investigate their toxicity on four fungi strains selected as a model of eukaryotic microorganisms (Phanerochaete chrysosporium, Aspergillus niger, Lentinus tigrinus and Candida cylindracea). Among these DESs, ChCl:ZnCl2 exhibited the highest inhibition zone diameter towards the tested fungi growth in vitro, followed by the acidic group (malonic acid and p-toluenesulfonic acid). Another study was conducted to test the acute toxicity and determine the lethal concentration at 50 % (LC50) of the same DESs on C. carpio fish. The inhibition range and LC50 of DESs were found to be different from their individual components. DESs were found to be less toxic than their mixture or individual components. The LC50 of ChCl:MADES is much higher than that of ChCl:MAMix. Moreover, the DESs acidic group showed a lower inhibition zone on fungi growth. Thus, DESs should be considered as new components with different physicochemical properties and toxicological profiles, and not merely compositions of compounds. PMID:26743645

  3. Gay-Berne and electrostatic multipole based coarse-grain potential in implicit solvent

    Science.gov (United States)

    Wu, Johnny; Zhen, Xia; Shen, Hujun; Li, Guohui; Ren, Pengyu

    2011-10-01

    A general, transferable coarse-grain (CG) framework based on the Gay-Berne potential and electrostatic point multipole expansion is presented for polypeptide simulations. The solvent effect is described by the Generalized Kirkwood theory. The CG model is calibrated using the results of all-atom simulations of model compounds in solution. Instead of matching the overall effective forces produced by atomic models, the fundamental intermolecular forces such as electrostatic, repulsion-dispersion, and solvation are represented explicitly at a CG level. We demonstrate that the CG alanine dipeptide model is able to reproduce quantitatively the conformational energy of all-atom force fields in both gas and solution phases, including the electrostatic and solvation components. Replica exchange molecular dynamics and microsecond dynamic simulations of polyalanine of 5 and 12 residues reveal that the CG polyalanines fold into "alpha helix" and "beta sheet" structures. The 5-residue polyalanine displays a substantial increase in the "beta strand" fraction relative to the 12-residue polyalanine. The detailed conformational distribution is compared with those reported from recent all-atom simulations and experiments. The results suggest that the new coarse-graining approach presented in this study has the potential to offer both accuracy and efficiency for biomolecular modeling.

  4. Improved Cellulose and Organic-Solvents based Lignocellulosic Fractionation Pre-treatment of Organic Waste for Bioethanol Production

    OpenAIRE

    Valeriy Bekmuradov; Grace Luk; Robin Luong

    2014-01-01

    This study investigates the performance of the Cellulose and Organic-Solvents based Lignocellulosic Fractionation (COSLIF) method for the pretreatment of Source-Separated Organic (SSO) waste. An improvement on the standard method of COSLIF pre-treatment was developed based on lower enzyme loading and using an ethanol washing instead of acetone. It was demonstrated that a much higher glucose yield (90% after 72 hours) was possible with this improvement, as compared to the original method, w...

  5. LSER-based modeling vapor pressures of (solvent+salt) systems by application of Xiang-Tan equation

    Institute of Scientific and Technical Information of China (English)

    Aynur Senol

    2015-01-01

    The study deals with modeling the vapor pressures of (solvent+salt) systems depending on the linear solvation energy relation (LSER) principles. The LSER-based vapor pressure model clarifies the simultaneous impact of the vapor pressure of a pure solvent estimated by the Xiang-Tan equation, the solubility and solvatochromic parameters of the solvent and the physical properties of the ionic salt. It has been performed independently two structural forms of the generalized solvation model, i.e. the unified solvation model with the integrated properties (USMIP) containing nine physical descriptors and the reduced property-basis solvation model. The vapor pressure data of fourteen (solvent+salt) systems have been processed to analyze statistical y the reliabil-ity of existing models in terms of a log-ratio objective function. The proposed vapor pressure approaches reproduce the observed performance relatively accurately, yielding the overall design factors of 1.0643 and 1.0702 for the integrated property-basis and reduced property-basis solvation models.

  6. Deep Eutectic Solvent-Based Microwave-Assisted Method for Extraction of Hydrophilic and Hydrophobic Components from Radix Salviae miltiorrhizae

    Directory of Open Access Journals (Sweden)

    Jue Chen

    2016-10-01

    Full Text Available Deep eutectic solvents (DESs have attracted significant attention as a promising green media. In this work, twenty-five kinds of benign choline chloride-based DESs with microwave-assisted methods were applied to quickly extract active components from Radix Salviae miltiorrhizae. The extraction factors, including temperature, time, power of microwave, and solid/liquid ratio, were investigated systematically by response surface methodology. The hydrophilic and hydrophobic ingredients were extracted simultaneously under the optimized conditions: 20 vol% of water in choline chloride/1,2-propanediol (1:1, molar ratio as solvent, microwave power of 800 W, temperature at 70 °C, time at 11.11 min, and solid/liquid ratio of 0.007 g·mL−1. The extraction yield was comparable to, or even better than, conventional methods with organic solvents. The microstructure alteration of samples before and after extraction was also investigated. The method validation was tested as the linearity of analytes (r2 > 0.9997 over two orders of magnitude, precision (intra-day relative standard deviation (RSD < 2.49 and inter-day RSD < 2.96, and accuracy (recoveries ranging from 95.04% to 99.93%. The proposed DESs combined with the microwave-assisted method provided a prominent advantage for fast and efficient extraction of active components, and DESs could be extended as solvents to extract and analyze complex environmental and pharmaceutical samples.

  7. An assessment of different solvent-based capture technologies within an IGCC–CCS power plant

    International Nuclear Information System (INIS)

    This study evaluates three different solvent absorption processes for the pre-combustion capture of CO2 for a black coal IGCC (Integrated Gasification Combined Cycle) power-plant, with the aim of determining the best solvent process for pre-combustion capture. The three solvent processes are MDEA (mono diethanolamine), hot potassium carbonate and Selexol™. The study involves detailed thermodynamic models of the entrained flow gasifier, synthesis gas processes, CO2 capture process and the gas turbine and steam turbine combined cycle plant. IGCC without capture yielded an efficiency of 45.02%. For the CO2 capture processes at 90% CO2 capture, the power generation efficiencies are almost identical for MDEA and Selexol™ with 36.39% and 36.42%, respectively. The IGCC with the hot potassium carbonate process yielded the highest efficiency with 37.33%. This improvement is attributed to the higher operating temperature of the absorber which allows water vapor in the synthesis gas to be sent to the gas turbine resulting in a greater power production from the gas turbine. A multi-objective optimization is performed by varying different decision variables in the IGCC with the hot potassium carbonate capture process. By optimizing these variables, an efficiency of 39.31% is obtained – a 2% point improvement for 90% capture. - Highlights: • The efficiency of a black coal IGCC process with solvent absorption CO2 capture is analyzed. • 3 different solvents: MDEA, Selexol™ and hot potassium carbonate are compared on a common basis. • The best solvent does not have the lowest energy consumption, but does give the highest gas turbine power output. • A further 2% point efficiency improvement can be achieved by preheating air using high grade heat from the gasifier

  8. In Vitro and In Vivo toxicity profiling of ammonium-based deep eutectic solvents.

    Directory of Open Access Journals (Sweden)

    Maan Hayyan

    Full Text Available The cytotoxic potential of ammonium-based deep eutectic solvents (DESs with four hydrogen bond donors, namely glycerine (Gl, ethylene glycol (EG, triethylene glycol (TEG and urea (U were investigated. The toxicity of DESs was examined using In Vitro cell lines and In Vivo animal model. IC50 and selectivity index were determined for the DESs, their individual components and their combinations as aqueous solutions for comparison purposes. The cytotoxicity effect of DESs varied depending on cell lines. The IC50 for the GlDES, EGDES, UDES and TEGDES followed the sequence of TEGDES< GlDES< EGDES< UDES for OKF6, MCF-7, A375, HT29 and H413, respectively. GlDES was selective against MCF-7 and A375, EGDES was selective against MCF-7, PC3, HepG2 and HT29, UDES was selective against MCF-7, PC3, HepG2 and HT29, and TEGDES was selective against MCF-7 and A375. However, acute toxicity studies using ICR mice showed that these DESs were relatively toxic in comparison to their individual components. DES did not cause DNA damage, but it could enhance ROS production and induce apoptosis in treated cancer cells as evidenced by marked LDH release. Furthermore, the examined DESs showed less cytotoxicity compared with ionic liquids. To the best of our knowledge, this is the first time that combined In Vitro and In Vivo toxicity profiles of DESs were being demonstrated, raising the toxicity issue of these neoteric mixtures and their potential applicability to be used for therapeutic purposes.

  9. The potential applications in heavy oil EOR with the nanoparticle and surfactant stabilized solvent-based emulsion

    Energy Technology Data Exchange (ETDEWEB)

    Qiu, F. [Texas A and M Univ., College Station, TX (United States)

    2010-07-01

    The main challenges in developing the heavy oil reservoirs in the Alaska North Slope (ANS) include technical challenges regarding thermal recovery; sand control and disposal; high asphaltene content; and low in-situ permeability. A chemical enhanced oil recovery method may be possible for these reservoirs. Solvent based emulsion flooding provides mobility control; oil viscosity reduction; and in-situ emulsification of heavy oil. This study evaluated the potential application of nano-particle-stabilized solvent based emulsion injection to enhance heavy oil recovery in the ANS. The optimized micro-emulsion composition was determined using laboratory tests such as phase behaviour scanning, rheology studies and interfacial tension measurements. The optimized nano-emulsions were used in core flooding experiments to verify the recovery efficiency. The study revealed that the potential use of this kind of emulsion flooding is a promising enhanced oil recovery process for some heavy oil reservoirs in Alaska, Canada and Venezuela. 4 refs., 2 tabs., 10 figs.

  10. Tailor-made design of J- or H-aggregated naphthalenediimide-based gels and remarkable fluorescence turn on/off behaviour depending on solvents.

    Science.gov (United States)

    Basak, Shibaji; Nandi, Nibedita; Baral, Abhishek; Banerjee, Arindam

    2015-01-14

    A naphthalenediimide (NDI)-based new gelator molecule has been discovered, the molecule forms interesting J/H-aggregated species depending on solvents (aliphatic/aromatic) and remarkably, the fluorescence of the gel phase materials is nicely tuned according to the electron donating capacity of the aromatic solvent. PMID:25426500

  11. A triarylboron-based fluorescent temperature indicator: sensitive both in solid polymers and in liquid solvents.

    Science.gov (United States)

    Liu, Xuan; Li, Shayu; Feng, Jiao; Li, Yi; Yang, Guoqiang

    2014-03-14

    A novel triarylboron compound, MPB, exhibiting reversible thermochromic dual-fluorescence in solid-state polymers and in liquid solvents was designed and synthesized. The fluorescent solid-state polymer with MPB can serve as a highly sensitive self-reference temperature indicator with a concentration independent feature. PMID:24481478

  12. Identification of Chlorinated Solvent Sources in the Indoor Air of Private Residences around Hill Air Force Base, Utah

    OpenAIRE

    Hall, Andrew Jensen

    2008-01-01

    Volatile chlorinated solvents such as trichloroethylene (TCE), 1,2 dichloroethane (1,2 DCA), and perchloroethylene (PCE) have been identified in the indoor air of residences located near Hill Air Force Base (AFB), Utah. These vapors can originate from either volatilization of contaminates from shallow contaminated groundwater and transport into residences or from sources within the residence. The focus of the thesis was the development of a testing strategy for determining sources of TCE, 1,2...

  13. The Effect of Temperature on Kinetics and Diffusion Coefficients of Metallocene Derivatives in Polyol-Based Deep Eutectic Solvents

    OpenAIRE

    Laleh Bahadori; Mohammed Harun Chakrabarti; Ninie Suhana Abdul Manan; Mohd Ali Hashim; Farouq Sabri Mjalli; Inas Muen AlNashef; Nigel Brandon

    2015-01-01

    The temperature dependence of the density, dynamic viscosity and ionic conductivity of several deep eutectic solvents (DESs) containing ammonium-based salts and hydrogen bond donvnors (polyol type) are investigated. The temperature-dependent electrolyte viscosity as a function of molar conductivity is correlated by means of Walden's rule. The oxidation of ferrocene (Fc/Fc+) and reduction of cobaltocenium (Cc+/Cc) at different temperatures are studied by cyclic voltammetry and potential-step c...

  14. Solvent substitution

    Energy Technology Data Exchange (ETDEWEB)

    1990-01-01

    The DOE Environmental Restoration and Waste Management Office of Technology Development and the Air Force Engineering and Services Center convened the First Annual International Workshop on Solvent Substitution on December 4--7, 1990. The primary objectives of this joint effort were to share information and ideas among attendees in order to enhance the development and implementation of required new technologies for the elimination of pollutants associated with industrial use of hazardous and toxic solvents; and to aid in accelerating collaborative efforts and technology transfer between government and industry for solvent substitution. There were workshop sessions focusing on Alternative Technologies, Alternative Solvents, Recovery/Recycling, Low VOC Materials and Treatment for Environmentally Safe Disposal. The 35 invited papers presented covered a wide range of solvent substitution activities including: hardware and weapons production and maintenance, paint stripping, coating applications, printed circuit boards, metal cleaning, metal finishing, manufacturing, compliance monitoring and process control monitoring. This publication includes the majority of these presentations. In addition, in order to further facilitate information exchange and technology transfer, the US Air Force and DOE solicited additional papers under a general Call for Papers.'' These papers, which underwent review and final selection by a peer review committee, are also included in this combined Proceedings/Compendium. For those involved in handling, using or managing hazardous and toxic solvents, this document should prove to be a valuable resource, providing the most up-to-date information on current technologies and practices in solvent substitution. Individual papers are abstracted separated.

  15. Solvent substitution

    International Nuclear Information System (INIS)

    The DOE Environmental Restoration and Waste Management Office of Technology Development and the Air Force Engineering and Services Center convened the First Annual International Workshop on Solvent Substitution on December 4--7, 1990. The primary objectives of this joint effort were to share information and ideas among attendees in order to enhance the development and implementation of required new technologies for the elimination of pollutants associated with industrial use of hazardous and toxic solvents; and to aid in accelerating collaborative efforts and technology transfer between government and industry for solvent substitution. There were workshop sessions focusing on Alternative Technologies, Alternative Solvents, Recovery/Recycling, Low VOC Materials and Treatment for Environmentally Safe Disposal. The 35 invited papers presented covered a wide range of solvent substitution activities including: hardware and weapons production and maintenance, paint stripping, coating applications, printed circuit boards, metal cleaning, metal finishing, manufacturing, compliance monitoring and process control monitoring. This publication includes the majority of these presentations. In addition, in order to further facilitate information exchange and technology transfer, the US Air Force and DOE solicited additional papers under a general ''Call for Papers.'' These papers, which underwent review and final selection by a peer review committee, are also included in this combined Proceedings/Compendium. For those involved in handling, using or managing hazardous and toxic solvents, this document should prove to be a valuable resource, providing the most up-to-date information on current technologies and practices in solvent substitution. Individual papers are abstracted separated

  16. Solvent exposure and malignant lymphoma: a population-based case-control study in Germany

    Directory of Open Access Journals (Sweden)

    Deeg Evelin

    2007-04-01

    Full Text Available Abstract Aims To analyze the relationship between exposure to chlorinated and aromatic organic solvents and malignant lymphoma in a multi-centre, population-based case-control study. Methods Male and female patients with malignant lymphoma (n = 710 between 18 and 80 years of age were prospectively recruited in six study regions in Germany (Ludwigshafen/Upper Palatinate, Heidelberg/Rhine-Neckar-County, Würzburg/Lower Frankonia, Hamburg, Bielefeld/Gütersloh, and Munich. For each newly recruited lymphoma case, a gender, region and age-matched (± 1 year of birth population control was drawn from the population registers. In a structured personal interview, we elicited a complete occupational history, including every occupational period that lasted at least one year. On the basis of job task-specific supplementary questionnaires, a trained occupational physician assessed the exposure to chlorinated hydrocarbons (trichloroethylene, tetrachloroethylene, dichloromethane, carbon tetrachloride and aromatic hydrocarbons (benzene, toluene, xylene, styrene. Odds ratios (OR and 95% confidence intervals (CI were calculated using conditional logistic regression analysis, adjusted for smoking (in pack years and alcohol consumption. To increase the statistical power, patients with specific lymphoma subentities were additionally compared with the entire control group using unconditional logistic regression analysis. Results We observed a statistically significant association between high exposure to chlorinated hydrocarbons and malignant lymphoma (Odds ratio = 2.1; 95% confidence interval 1.1–4.3. In the analysis of lymphoma subentities, a pronounced risk elevation was found for follicular lymphoma and marginal zone lymphoma. When specific substances were considered, the association between trichloroethylene and malignant lymphoma was of borderline statistical significance. Aromatic hydrocarbons were not significantly associated with the lymphoma diagnosis

  17. Novel shortcut estimation method for regeneration energy of amine solvents in an absorption-based carbon capture process.

    Science.gov (United States)

    Kim, Huiyong; Hwang, Sung June; Lee, Kwang Soon

    2015-02-01

    Among various CO2 capture processes, the aqueous amine-based absorption process is considered the most promising for near-term deployment. However, the performance evaluation of newly developed solvents still requires complex and time-consuming procedures, such as pilot plant tests or the development of a rigorous simulator. Absence of accurate and simple calculation methods for the energy performance at an early stage of process development has lengthened and increased expense of the development of economically feasible CO2 capture processes. In this paper, a novel but simple method to reliably calculate the regeneration energy in a standard amine-based carbon capture process is proposed. Careful examination of stripper behaviors and exploitation of energy balance equations around the stripper allowed for calculation of the regeneration energy using only vapor-liquid equilibrium and caloric data. Reliability of the proposed method was confirmed by comparing to rigorous simulations for two well-known solvents, monoethanolamine (MEA) and piperazine (PZ). The proposed method can predict the regeneration energy at various operating conditions with greater simplicity, greater speed, and higher accuracy than those proposed in previous studies. This enables faster and more precise screening of various solvents and faster optimization of process variables and can eventually accelerate the development of economically deployable CO2 capture processes.

  18. Evaluation of solvent system for the enzymatic synthesis of ethanol-based biodiesel from sludge palm oil (SPO).

    Science.gov (United States)

    Nasaruddin, Ricca Rahman; Alam, Md Zahangir; Jami, Mohammed Saedi

    2014-02-01

    A green technology of biodiesel production focuses on the use of enzymes as the catalyst. In enzymatic biodiesel synthesis, suitable solvent system is very essential to reduce the inhibition effects of the solvent to the enzymes. This study produced ethanol-based biodiesel from a low-cost sludge palm oil (SPO) using locally-produced Candida cylindracea lipase from fermentation of palm oil mill effluent (POME) based medium. The optimum levels of ethanol-to-SPO molar ratio and enzyme loading were found to be 4:1 and 10 U/25 g of SPO respectively with 54.4% w/w SPO yield of biodiesel and 21.7% conversion of free fatty acid (FFA) into biodiesel. Addition of tert-butanol at 2:1 tert-butanol-to-SPO molar ratio into the ethanol-solvent system increased the yield of biodiesel to 71.6% w/w SPO and conversion of FFA into biodiesel to 28.8%. The SPO and ethanol have promising potential for the production of renewable biodiesel using enzymatic-catalyzed esterification and transesterification.

  19. Solvent-free melting techniques for the preparation of lipid-based solid oral formulations.

    Science.gov (United States)

    Becker, Karin; Salar-Behzadi, Sharareh; Zimmer, Andreas

    2015-05-01

    Lipid excipients are applied for numerous purposes such as taste masking, controlled release, improvement of swallowability and moisture protection. Several melting techniques have evolved in the last decades. Common examples are melt coating, melt granulation and melt extrusion. The required equipment ranges from ordinary glass beakers for lab scale up to large machines such as fluid bed coaters, spray dryers or extruders. This allows for upscaling to pilot or production scale. Solvent free melt processing provides a cost-effective, time-saving and eco-friendly method for the food and pharmaceutical industries. This review intends to give a critical overview of the published literature on experiences, formulations and challenges and to show possibilities for future developments in this promising field. Moreover, it should serve as a guide for selecting the best excipients and manufacturing techniques for the development of a product with specific properties using solvent free melt processing.

  20. Tetrabutylammonium Bromide (TBABr)-Based Deep Eutectic Solvents (DESs) and Their Physical Properties

    OpenAIRE

    Rizana Yusof; Emilia Abdulmalek; Kamaliah Sirat; Mohd. Basyaruddin Abdul Rahman

    2014-01-01

    Density, viscosity and ionic conductivity data sets of deep eutectic solvents (DESs) formed by tetrabutylammonium bromide (TBABr) paired with ethlyene glycol, 1,3-propanediol, 1,5-pentanediol and glycerol hydrogen bond donors (HBDs) are reported. The properties of DES were measured at temperatures between 303 K and 333 K for HBD percentages of 66.7% to 90%. The effects of HBDs under different temperature and percentages are systematically analyzed. As expected, the measured density and viscos...

  1. DFT-based simulations of amide I' IR spectra of a small protein in solution using empirical electrostatic map with a continuum solvent model.

    Science.gov (United States)

    Welch, William R W; Kubelka, Jan

    2012-09-01

    A continuum solvent model was tested for simulations of amide I' IR spectra for a 40-residue subdomain of P22 viral coat protein in aqueous solution. Spectra obtained using DFT (BPW91/6-31G**) parameters for a reduced all-Ala representation of the protein were corrected by an electrostatic potential map obtained from the solvent cavity surface and AMBER99 side-chain atom partial charges. Various cavity sizes derived from van der Waals atomic radii with an added effective solvent radius up to 2.0 Å were tested. The interplay of the side-chain and solvent electrostatic effects was investigated by considering the side chains and solvent separately as well as together. The sensitivity to side-chain conformational fluctuations and to the parametrization of C(β) group partial charges was also tested. Simulation results were compared to the experimental amide I' spectra of P22 subdomain, including two (13)C isotopically edited variants, as well as to the previous simulations based on the molecular dynamics trajectory in explicit solvent. For small cavity sizes, between van der Waals and that with added solvent radius of 0.5 Å, better qualitative agreement with experiment was obtained than with the explicit solvent representation, in particular for the (13)C-labeled spectra. Larger protein cavities led to progressively worse predictions due to increasingly stronger electrostatic effects of side chains, which could no longer be well compensated for by the solvent potential. Balance between side-chain and solvent electrostatic effects is important in determining the width and shape of the simulated amide I', which is also virtually unaffected by side-chain-geometry fluctuations. The continuum solvent model combined with the electrostatic map is a computationally efficient and potentially robust approach for the simulations of IR spectra of proteins in solution.

  2. Impact of solvents and supercritical CO{sub 2} drying on the morphology and structure of polymer-based biofilms

    Energy Technology Data Exchange (ETDEWEB)

    Causa, Andrea; Acierno, Domenico; Filippone, Giovanni [Dipartimento di Ingegneria Chimica, dei Materiali e della Produzione Industriale, Università di Napoli Federico II, Piazzale V. Tecchio, 80, 80125 Napoli (Italy); Salerno, Aurelio; Domingo, Concepción [Instituto de Ciencia de Materiales de Barcelona (ICMAB-CSIC), Campus de la UAB, 08193 Bellaterra (Spain)

    2014-05-15

    In the present work, two-dimensional systems based on biodegradable polymers such as poly(ε-caprolactone) (PCL), poly(ethylene oxide) (PEO) and polylactic acid (PLA) are fabricated by means of a sustainable approach which consists in inducing phase separation in solutions of such polymers and “green” solvents, namely ethyl lactate (EL) and ethyl acetate (EA). The extraction of the solvent is promoted by a controlled drying process, which is performed in either air or supercritical CO{sub 2}. The latter can indeed act as both an antisolvent, which favors the deposition of the polymer by forming a mixture with EL and EA, and a plasticizing agent, whose solvation and transport properties may considerably affect the microstructure and crystallinity of the polymer films. The morphological, topographical and crystalline properties of the films are tailored through a judicial selection of the materials and the processing conditions and assessed by means of thermal analyses, polarized optical microscopy, scanning electron microscopy and confocal interferometric microscopy. The results show that the morphological and crystalline properties of the films are strongly dependent on the choice of both the polymer/solvent system and the operating conditions during the drying step. In particular, the morphological, topographical and thermal properties of films prepared starting from highly crystalline polymers, namely PCL and PEO, are greatly affected by the crystallization of the material. Conversely, the less crystalline PLA forms almost completely amorphous films.

  3. Direct and ultrasensitive optofluidic-based immunosensing assay of aflatoxin M1 in dairy products using organic solvent extraction.

    Science.gov (United States)

    Lou, Xuening; Zhu, Anna; Wang, Hongliang; Wu, Jun; Zhou, Liping; Long, Feng

    2016-10-12

    Aflatoxin M1 (AFM1), a highly toxic secondary metabolite, is present in a wide range of dairy products. In this study, we designed a simple, low-cost, reusable, and easy-to-operate immunosensing method for ultrasensitive detection of AFM1 in dairy products by using a portable evanescent wave-based optofluidic biosensing platform (EOBP). The developed method provides the minimum detection limit of 5 ng/L, which is below the most restrictive standard imposed by the current regulations for AFM1 in dairy products. The effect of several organic solvents, such as methanol, acetone, and acetonitrile, on the binding reaction of antibody-antigen in heterogeneous and homogeneous solutions was evaluated. Although the effect of organic solvents on the homogeneous binding reaction between antibody and antigen is more significant than that of heterogeneous binding reaction between antibody in solution and antigen immobilized onto the sensor surface, the fluorescence signal detected by EOBP is linearly dependent on AFM1 concentration. Therefore, AFM1 can be directly quantified even if the samples contain a certain organic solvent concentration. The robustness and stability of AFM1-ovalbumin conjugate allow the regeneration of modified biosensor surface for more than 200 times, thereby achieving a cost-effective and reliable AFM1 determination. The proposed method provides a rapid, ultrasensitive, and reliable AFM1 determination in dairy products without complicated sample pretreatment process. PMID:27662766

  4. Alternative Bio-Based Solvents for Extraction of Fat and Oils: Solubility Prediction, Global Yield, Extraction Kinetics, Chemical Composition and Cost of Manufacturing

    Directory of Open Access Journals (Sweden)

    Anne-Gaëlle Sicaire

    2015-04-01

    Full Text Available The present study was designed to evaluate the performance of alternative bio-based solvents, more especially 2-methyltetrahydrofuran, obtained from crop’s byproducts for the substitution of petroleum solvents such as hexane in the extraction of fat and oils for food (edible oil and non-food (bio fuel applications. First a solvent selection as well as an evaluation of the performance was made with Hansen Solubility Parameters and the COnductor-like Screening MOdel for Realistic Solvation (COSMO-RS simulations. Experiments were performed on rapeseed oil extraction at laboratory and pilot plant scale for the determination of lipid yields, extraction kinetics, diffusion modeling, and complete lipid composition in term of fatty acids and micronutrients (sterols, tocopherols and tocotrienols. Finally, economic and energetic evaluations of the process were conducted to estimate the cost of manufacturing using 2-methyltetrahydrofuran (MeTHF as alternative solvent compared to hexane as petroleum solvent.

  5. A new decomposition-based computer-aided molecular/mixture design methodology for the design of optimal solvents and solvent mixtures

    DEFF Research Database (Denmark)

    Karunanithi, A.T.; Achenie, L.E.K.; Gani, Rafiqul

    2005-01-01

    This paper presents a novel computer-aided molecular/mixture design (CAMD) methodology for the design of optimal solvents and solvent mixtures. The molecular/mixture design problem is formulated as a mixed integer nonlinear programming (MINLP) model in which a performance objective...... is to be optimized subject to structural, property, and process constraints. The general molecular/mixture design problem is divided into two parts. For optimal single-compound design, the first part is solved. For mixture design, the single-compound design is first carried out to identify candidates...... the design of an optimal extractant for the separation of acetic acid from water by liquid-liquid extraction. The results suggest that the new extractant would be able to perform better than the extractant being widely used for this separation. The second case study is an industrial problem involving...

  6. A Diazonium Salt-Based Ionic Liquid for Solvent-FreeModification of Carbon.

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Chengdu [ORNL; Huang, Jing-Fang [ORNL; Li, Zuojiang [ORNL; Luo, Huimin [ORNL; Dai, Sheng [ORNL

    2006-01-01

    A novel ionic liquid that consists of p-butylbenzenediazonium ions and bis(trifluoromethanesulfonyl)amidates (Tf{sub 2}N{sup -}) has been synthesized as a task-specific ionic liquid for the solvent-free modification of carbon materials. The use of anions Tf{sub 2}N{sup =} is the key to rendering the hydrophobicity, low liquidus temperature, and ionicity to this novel molten salt. This diazonium salt has a melting point of 7.2 C and a moderate electric conductivity of 527 {micro} s/cm at 25 C. The thermal stability of this diazonium ionic liquid has been investigated by high-resolution thermogravimetric analysis (HRTGA). The compound is stable up to about 90 C in nitrogen, which is only 10 C less than its solid tetrafluoroborate counterpart. The modification of carbon materials has been carried out through both thermal and electrochemical activations of diazonium ions to generate free radical intermediates without the use of any solvent. The surface-coverage loadings of 3.38 {micro} mol/m{sup 2} and 6.07 {micro} mol/m{sup 2} for covalently attached organic functionalities have been achieved by the thermally induced functionalization and electrochemically assisted reaction, respectively.

  7. Benchtop fabrication of microfluidic systems based on curable polymers with improved solvent compatibility.

    Science.gov (United States)

    Hashimoto, Michinao; Langer, Robert; Kohane, Daniel S

    2013-01-21

    This paper describes a general scheme to fabricate microchannels from curable polymers on a laboratory benchtop. Using the scheme described here, benchtop fabrication of SU-8 microfluidic systems was demonstrated for the first time, and their compatibility with organic solvents was demonstrated. The fabrication process has three major stages: 1) transferring patterns of microchannels to polymer films by molding, 2) releasing the patterned film and creating inlets and outlets for fluids, and 3) sealing two films together to create a closed channel system. Addition of a PDMS slab supporting the polymer film provided structural integrity during and after fabrication, allowing manipulation of the polymer films without fracturing or deformation. SU-8 channels fabricated according to this scheme exhibited solvent compatibility against continuous exposure to acetone and ethylacetate, which are incompatible with native PDMS. Using the SU-8 channels, continuous generation of droplets of ethylacetate, and templated synthesis of poly (lactic-co-glycolic acid) (PLGA) microparticles, both with stable size, were demonstrated continuously over 24 h, and at intervals over 75 days. PMID:23192674

  8. Solubilities and thermodynamic properties of CO2 in choline-chloride based deep eutectic solvents

    International Nuclear Information System (INIS)

    Highlights: • Solubilities of carbon dioxide in three deep eutectic solvents (DESs) have been reported. • The experimental data were reduced to Henry’s law constants. • The Gibbs free energy, enthalpy, and entropy changes were calculated. • Relationship between solubility and structure of DESs was developed. - Abstract: The solubilities of CO2 in three kinds of deep eutectic solvents, (choline chloride + phenol), (choline chloride + diethylene glycol) and (choline chloride + triethylene glycol), were determined at temperatures ranging from 293.15 K to 323.15 K under pressures up to 600.0 kPa using isochoric saturation method. The mole ratios of choline chloride to phenol were selected as 1:2, 1:3 and 1:4, the others as 1:3 and 1:4. Henry’s constants and thermodynamic properties such as standard Gibbs free energy, enthalpy, and entropy changes of CO2 solvation were calculated from the correlation of solubility data. Results revealed that the solubility of CO2 increased with increasing pressure and decreased with increasing temperature. The enthalpies of solution were negative at all conditions

  9. Solvent substitutes

    International Nuclear Information System (INIS)

    The environmental and industrial hygiene regulations promulgated since 1980, most notably the Superfund Amendments and Reauthorization Act (SARA), the Hazardous and Solid Waste Amendments to the Resources Conservation and Recovery Act (RCRA), and the Clean Air Act Amendments of 1990, have brought about an increased emphasis on user exposure, hazardous waste generation, and air emissions. As a result, industry is performing a fundamental reassessment of cleaning solvents, processes, and procedures. The more progressive organizations have made their goal the elimination of solvents that may pose significant potential human health and environmental hazards. This chapter discusses solvent cleaning in metal-finishing, metal-manufacturing, and industrial maintenance applications; precision cleaning; and electronics manufacturing. Nonmetallic cleaning, adhesives, coatings, inks, and aerosols also will be addressed, but in a more cursory manner

  10. Mechanism of gold solvent extraction from aurocyanide solution by quaternary amines: models of extracting species based on hydrogen bonding

    Institute of Scientific and Technical Information of China (English)

    马刚; 闫文飞; 陈景; 严纯华; 高宏成; 周维金; 施鼐; 吴谨光; 徐光宪; 黄昆; 余建民; 崔宁

    2000-01-01

    The mechanism of gold solvent extraction from KAu(CN)2 solution was investigated by means of FTIR, EXAFS, ICP and radioactive tracer methods. Two extraction systems were studied, namely N263-tributyl phosphate(TBP)-n-dodecane and N263-iso-octanol-n-dodecane. High-resolution FT IR spectroscopy indicated that the CN stretching vibrations of the two extraction systems differred greatly. In order to interpret the significant difference in CN stretching vibrations, twoextracting species models are proposed——supramolecular structures based on the formation ofhydrogen bonds between Au(CN)2- and modifiers such as TBP and iso-octanol.

  11. Mechanism of gold solvent extraction from aurocyanide solution by quaternary amines: models of extracting species based on hydrogen bonding

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The mechanism of gold solvent extraction from KAu(CN)2 solution was investigated by means of FTIR, EXAFS, ICP and radioactive tracer methods. Two extraction systems were studied, namely N263-tributyl phosphate(TBP)-n-dodecane and N263-iso-octanol-n-dodecane. High-reso- lution FT IR spectroscopy indicated that the CN stretching vibrations of the two extraction systems differred greatly. In order to interpret the significant difference in CN stretching vibrations, two extracting species models are proposed supramolecular structures based on the formation of hydrogen bonds between Au(CN)2- and modifiers such as TBP and iso-octanol.

  12. Fast environment-friendly ball mill-assisted deep eutectic solvent-based extraction of natural products.

    Science.gov (United States)

    Wang, Man; Wang, Jiaqin; Zhang, Yue; Xia, Qian; Bi, Wentao; Yang, Xiaodi; Chen, David Da Yong

    2016-04-22

    A fast environment-friendly extraction method, ball mill-assisted deep eutectic solvent-based extraction, was used for the extraction of natural products from plants. In this study, tanshinones were selected as target compounds to evaluate the efficiency of the developed extraction method. Under the optimized experimental conditions, cryptotanshinone (0.176mg/g), tanshinone I (0.181mg/g), and tanshinone II A (0.421mg/g) were extracted from Salvia miltiorrhiza Bunge, and the developed method was found to be greener, more efficient, and faster than conventional, environmentally harmful extraction methods such as methanol-based ultrasound-assisted extraction and heat reflux extraction. The analytical performances including recovery, reproducibility (RSD, n=5), correlation of determination (r(2)), and the limit of detection, with the ranges of 96.1-103.9%, 1.6-1.9%, 0.9973-0.9984, and 5-8ng/mL, were respectively obtained. Application of ball mill-assisted deep eutectic solvent-based extraction may fundamentally shape the future development of extraction methods. PMID:27033981

  13. The Effects of Solvent and Added Bases on the Protection of Benzylamines with Carbon Dioxide

    Directory of Open Access Journals (Sweden)

    Amy L. Ethier

    2015-06-01

    Full Text Available The introduction and removal of protecting groups is ubiquitous in multi-step synthetic schemes. From a green chemistry standpoint, however, alternative strategies that employ in situ and reversible protection and deprotection sequences would be attractive. The reversible reactions of CO2 with amines could provide a possible vehicle for realizing this strategy. Herein, we present (1 the products of reaction of benzylamines with CO2 in a variety of solvents with and without the presence of basic additives; (2 new adducts associated with CO2 protected benzylamine in acetonitrile containing 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU; and (3 the intermolecular competitive acylation of benzylamine and benzyl alcohol and the intramolecular competitive acylation of (4-aminomethylphenyl methanol with isopropenyl acetate in acetonitrile containing DBU in the absence and presence of CO2.

  14. Tetrabutylammonium Bromide (TBABr-Based Deep Eutectic Solvents (DESs and Their Physical Properties

    Directory of Open Access Journals (Sweden)

    Rizana Yusof

    2014-06-01

    Full Text Available Density, viscosity and ionic conductivity data sets of deep eutectic solvents (DESs formed by tetrabutylammonium bromide (TBABr paired with ethlyene glycol, 1,3-propanediol, 1,5-pentanediol and glycerol hydrogen bond donors (HBDs are reported. The properties of DES were measured at temperatures between 303 K and 333 K for HBD percentages of 66.7% to 90%. The effects of HBDs under different temperature and percentages are systematically analyzed. As expected, the measured density and viscosity of the studied DESs decreased with an increase in temperature, while ionic conductivity increases with temperature. In general, DESs made of TBABr and glycerol showed the highest density and viscosity and the lowest ionic conductivity when compared to other DESs. The presence of an extra hydroxyl group on glycerol in a DES affected the properties of the DES.

  15. AIE Based Coumarin Chromophore - Evaluation and Correlation Between Solvatochromism and Solvent Polarity Parameters.

    Science.gov (United States)

    Lanke, Sandip K; Sekar, Nagaiyan

    2016-03-01

    A new class of red emitting extensively conjugated donor-π-acceptor type dyes bearing coumarin units have been synthesized by condensation of 7-(diethylamino)-2-oxo-2 H-chromene-3-carbaldehyde with different active methylenes. All the dyes are characterized by (1)H NMR, (13)C NMR and HRMS spectroscopy. The photophysical behaviour and the relation between structure and properties of the coumarin "push-pull" derivatives were investigated experimentally. The dyes exhibited positive solvatochromism and solvatofluorism in solution of varying polarity. These coumarin dyes show aggregation induced emission properties with red emitting fluorescence. They show absorption in the range of 501-528 and emission in the range of 547-630 nm. We evaluated photophysical properties of coumarin dyes using solvotochromism and solvent dependent shift in the emission wavelength. All the synthesized coumarin dyes COS1-COS4 are showing very good solvatochromic properties.

  16. Development of green betaine-based deep eutectic solvent aqueous two-phase system for the extraction of protein.

    Science.gov (United States)

    Li, Na; Wang, Yuzhi; Xu, Kaijia; Huang, Yanhua; Wen, Qian; Ding, Xueqin

    2016-05-15

    Six kinds of new type of green betaine-based deep eutectic solvents (DESs) have been synthesized. Deep eutectic solvent aqueous two-phase systems (DES-ATPS) were established and successfully applied in the extraction of protein. Betaine-urea (Be-U) was selected as the suitable extractant. Single factor experiments were carried out to determine the optimum conditions of the extraction process, such as the salt concentration, the mass of DES, the separation time, the amount of protein, the temperature and the pH value. The extraction efficiency could achieve to 99.82% under the optimum conditions. Mixed sample and practical sample analysis were discussed. The back extraction experiment was implemented and the back extraction efficiency could reach to 32.66%. The precision experiment, repeatability experiment and stability experiment were investigated. UV-vis, FT-IR and circular dichroism (CD) spectra confirmed that the conformation of protein was not changed during the process of extraction. The mechanisms of extraction were researched by dynamic light scattering (DLS), the measurement of the conductivity and transmission electron microscopy (TEM). DES-protein aggregates and embraces phenomenon play considerable roles in the separation process. All of these results indicated that betaine-based DES-ATPS may provide a potential substitute new method for the separation of proteins. PMID:26992491

  17. How do evaporating thin films evolve? Unravelling phase-separation mechanisms during solvent-based fabrication of polymer blends

    KAUST Repository

    Wodo, Olga

    2014-10-13

    © 2014 AIP Publishing LLC. Solvent-based fabrication is a flexible and affordable approach to manufacture polymer thin films. The properties of products made from such films can be tailored by the internal organization (morphology) of the films. However, a precise knowledge of morphology evolution leading to the final film structure remains elusive, thus limiting morphology control to a trial and error approach. In particular, understanding when and where phases are formed, and how they evolve would provide rational guidelines for more rigorous control. Here, we identify four modes of phase formation and subsequent propagation within the thinning film during solvent-based fabrication. We unravel the origin and propagation characteristics of each of these modes. Finally, we construct a mode diagram that maps processing conditions with individual modes. The idea introduced here enables choosing processing conditions to tailor film morphology characteristics and paves the ground for a deeper understanding of morphology control with the ultimate goal of precise, yet affordable, morphology manipulation for a large spectrum of applications.

  18. Advanced solvent based methods for molecular characterization of soil organic matter by high-resolution mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Tfaily, Malak M.; Chu, Rosalie K.; Tolic, Nikola; Roscioli, Kristyn M.; Anderton, Christopher R.; Pasa-Tolic, Ljiljana; Robinson, Errol W.; Hess, Nancy J.

    2015-05-19

    Soil organic matter (SOM) a complex, heterogeneous mixture of above and belowground plant litter and animal and microbial residues at various degrees of decomposition, is a key reservoir for carbon (C) and nutrient biogeochemical cycling in soil based ecosystems. A limited understanding of the molecular composition of SOM limits the ability to routinely decipher chemical processes within soil and predict accurately how terrestrial carbon fluxes will response to changing climatic conditions and land use. To elucidate the molecular-level structure of SOM, we selectively extracted a broad range of intact SOM compounds by a combination of different organic solvents from soils with a wide range of C content. Our use of Electrospray ionization (ESI) coupled with Fourier transform ion cyclotron resonance mass spectrometry (FTICR MS) and a suite of solvents with varying polarity significantly expands the inventory of the types of organic molecules present in soils. Specifically, we found that hexane is selective for lipid-like compounds with very low O:C ratios; water was selective for carbohydrates with high O:C ratios; acetonitrile preferentially extracts lignin, condensed structures, and tannin poly phenolic compounds with O:C > 0.5; methanol has higher selectivity towards compounds characterized with low O:C < 0.5; and hexane, MeOH, ACN and water solvents increase the number and types of organic molecules extracted from soil for a broader range of chemically diverse soil types. Our study of SOM molecules by ESI-FTICR MS revealed new insight into the molecular-level complexity of organics contained in soils.

  19. A solvent-controlled switch of manganese complex assemblies with a beta-diketonate-based ligand.

    Science.gov (United States)

    Aromí, Guillem; Gamez, Patrick; Roubeau, Olivier; Berzal, Paula Carrero; Kooijman, Huub; Spek, Anthony L; Driessen, Willem L; Reedijk, Jan

    2002-07-15

    The coordination properties of the new polynucleating ligand H(3)L1 (1,3-bis(3-oxo-3-phenylpropionyl)-2-hydroxy-5-methylbenzene) with Mn(II/III) are described. Depending on the solvent used, the reaction of H(3)L1 with Mn(OAc)(2) yields either of the two new multinuclear assemblies [Mn(2)(HL1)(2)(py)(4)] (1) and [Mn(3)(HL1)(3)] (2), as revealed by X-ray crystallography. The structure of 2 is remarkable in that it shows a unique asymmetric triple-stranded helicate. Complexes 1 and 2 can be interconverted by controlling the solvent of the reaction system, and therefore, this ensemble constitutes an interesting externally addressable switch. In the presence of Mn(III)/pyridine, partial degradation of H(3)L1 occurs via oxidative cleavage, and the new complex [Mn(2)(L2)(2)(py)(4)] (3) is formed. The crystal structure of this complex has shown the fully deprotonated form of the new donor H(3)L2 (3-(3-oxo-3-phenylpropionyl)-5-methylsalicylic acid). From the same reaction, the Mn(II) complex 1 is also obtained. A rational synthesis of H(3)L2 is reported, and this has been used to prepare 3 in high yields, directly from its components. Variable-temperature magnetic susceptibility (chi(m)) measurements were performed on complexes 1-3 under a magnetic field of 1 kG. The data for each complex were fit to the appropriate chi(m) vs T theoretical equation, respectively. In 1, the Mn(II) ions are uncoupled, with g = 2.01. The data from 2 were fit by assuming the presence of an exchange coupled Mn(II)...Mn(II) pair next to a magnetically isolated Mn(II) center. The fit gave J = -2.75 cm(-1), g(12) = 1.97, and g(3) = 1.92, respectively. In 3, two models fit the experimental data. In the most satisfactory, the Mn(III) ions are coupled antiferromagnetically with J = -1.48 cm(-1) and g = 1.98 and a term for weak ferromagnetic intermolecular exchange is included with zJ' = 0.39 cm(-1). The other model contemplates the presence of two uncoupled zero field split Mn(III) ions.

  20. Effect of Organic Solvents in Preparation of Silica-Based Chemical Gel Decontaminates for Decontamination of Nuclear Facilities

    International Nuclear Information System (INIS)

    Decontamination of nuclear facilities is necessary to reduce the radiation field during normal operations and decommissioning of complex equipment such as stainless steel components, other iron-based steel and alloys, metal surfaces, structural materials and so on. Chemical decontamination technology in particular is a highly effective method to remove the radioactive contamination through a chemical dissolution or a redox reaction. However, this method has the serious drawback due to the generation of large amounts of the radioactive liquid wastes. Recently, a few literatures have been reported for the preparation of the chemical gel decontaminants to reduce the amount of the radioactive liquid wastes and to enhance the decontamination efficiency through increasing the contact time between the gels and the radioactive contaminants. In the preparation of the chemical gels, the control of the viscosity highly depends on the amount of a coviscosifier used among the components of the chemical gels consisted of a viscosifier, a coviscosifier, and a chemical decontaminant. In this works, a new effective method for the preparation of the chemical gel was investigated by introducing the organic solvents. The mixture solution of the coviscosifier and organic solvent was more effective in the control of the viscosity compared with that of the coviscosifier only in gels. Furthermore, the decontamination efficiency of the chemical gels measured by using the multi-channel analyzer (MCA) showed the high decontamination factor for Co-60 and Cs-137 contaminated on the surface of the stainless steel 304

  1. Tuning Microparticle Porosity during Single Needle Electrospraying Synthesis via a Non-Solvent-Based Physicochemical Approach

    Directory of Open Access Journals (Sweden)

    Yuan Gao

    2015-12-01

    Full Text Available Porous materials, especially microparticles (MP, are utilized in almost every field of engineering and science, ranging from healthcare materials (drug delivery to tissue engineering to environmental engineering (biosensing to catalysis. Here, we utilize the single needle electrospraying technique (as opposed to complex systems currently in development to prepare a variety of poly(ε-caprolactone (PCL MPs with diverse surface morphologies (variation in pore size from 220 nm to 1.35 µm and architectural features (e.g., ellipsoidal, surface lamellar, Janus lotus seedpods and spherical. This is achieved by using an unconventional approach (exploiting physicochemical properties of a series of non-solvents as the collection media via a single step. Sub-micron pores presented on MPs were visualized by electron microscopy (demonstrating a mean MP size range of 7–20 μm. The present approach enables modulation in morphology and size requirements for specific applications (e.g., pulmonary delivery, biological scaffolds, multi-stage drug delivery and biomaterial topography enhancement. Differences in static water contact angles were observed between smooth and porous MP-coated surfaces. This reflects the hydrophilic/hydrophobic properties of these materials.

  2. Quantum Chemical Insight into the Interactions and Thermodynamics Present in Choline Chloride Based Deep Eutectic Solvents.

    Science.gov (United States)

    Wagle, Durgesh V; Deakyne, Carol A; Baker, Gary A

    2016-07-14

    We report quantum chemical calculations performed on three popular deep eutectic solvents (DESs) in order to elucidate the molecular interactions, charge transfer interactions, and thermodynamics associated with these systems. The DESs studied comprise 1:2 choline chloride/urea (reline), 1:2 choline chloride/ethylene glycol (ethaline), and 1:1 choline chloride/malonic acid (maloline). The excellent correlation between calculated and experimental vibrational spectra allowed for identification of dominant interactions in the DES systems. The DESs were found to be stabilized by both conventional hydrogen bonds and C-H···O/C-H···π interactions between the components. The hydrogen-bonding network established in the DES is clearly distinct from that which exists within the neat hydrogen-bond donor dimer. Charge decomposition analysis indicates significant charge transfer from choline and chloride to the hydrogen-bond donor with a higher contribution from the cation, and a density of states analysis confirms the direction of the charge transfer. Consequently, the sum of the bond orders of the choline-Cl(-) interactions in the DESs correlates directly with the melting temperatures of the DESs, a correlation that offers insight into the effect of the tuning of the choline-Cl(-) interactions by the hydrogen-bond donors on the physical properties of the DESs. Finally, the differences in the vibrational entropy changes upon DES formation are consistent with the trend in the overall entropy changes upon DES formation. PMID:27268431

  3. Large-scale solvent-swelling-based amplification of microstructured sharkskin

    International Nuclear Information System (INIS)

    Sophisticated biomimetic microstructures/nanostructures have attracted attention worldwide, but their fabrication technique significantly restricts their application. This study uses natural sharkskin to investigate amplification (i.e., the bioscaling forming process) and thus acquire a complex microstructure that cannot be fabricated by traditional micromachining techniques. The bioscaling forming process adjusts the optimal function region of natural surfaces by utilizing the solvent-swelling effect of polydimethylsiloxane. To accurately replicate amplified sharkskin, the swelling ratio and rate in gaseous and liquid n-hexane were investigated. Epoxy resin was used to produce a positive sharkskin mold. A comparison between the microstructure of the original and amplified sharkskin shows that the swelling ratio can reach a maximum of 34% with gaseous n-hexane and 39% with liquid n-hexane. The accuracy of bioscaling forming was higher than 95%. The drag-reducing effect was also tested. When the sharkskin was amplified 1.34 times, the optimal velocity range of the drag reduction moved from 5.0 to 3.5 m s−1. (paper)

  4. Enzyme-Catalyzed Henry Reaction in Choline Chloride-Based Deep Eutectic Solvents.

    Science.gov (United States)

    Tian, Xuemei; Zhang, Suoqin; Zheng, Liangyu

    2016-01-01

    The enzyme-catalyzed Henry reaction was realized using deep eutectic solvents (DESs) as a reaction medium. The lipase from Aspergillus niger (lipase AS) showed excellent catalytic activity toward the substrates aromatic aldehydes and nitromethane in choline chloride:glycerol at a molar ratio of 1:2. Addition of 30 vol% water to DES further improved the lipase activity and inhibited DES-catalyzed transformation. A final yield of 92.2% for the lipase AS-catalyzed Henry reaction was achieved under optimized reaction conditions in only 4 h. In addition, the lipase AS activity was improved by approximately 3-fold in a DES-water mixture compared with that in pure water, which produced a final yield of only 33.4%. Structural studies with fluorescence spectroscopy showed that the established strong hydrogen bonds between DES and water may be the main driving force that affects the spatial conformation of the enzyme, leading to a change in lipase activity. The methodology was also extended to the aza-Henry reaction, which easily occurred in contrast to that in pure water. The enantioselectivity of both Henry and aza-Henry reactions was not found. However, the results are still remarkable, as we report the first use of DES as a reaction medium in a lipase-catalyzed Henry reaction. PMID:26437947

  5. A volatile-solvent gas fiber sensor based on polyaniline film coated on superstructure fiber Bragg gratings

    International Nuclear Information System (INIS)

    A fiber sensor based on a polyaniline (PANI) film that is coated on the surface of an etched superstructure fiber grating to detect volatile solvent vapors is experimentally demonstrated. This sensing mechanism is based on the interaction of the testing gas with the polyaniline coating film, which changes the film index, resulting in a shift in the Bragg wavelength. The sensitivity of this sensor to ammonia (NH3) gas is about 0.073 pm ppm−1, which depends on the optical characteristics of the fiber grating, the diameter of the fiber cladding and the constituents of the sensing film. Methanol concentrations can also be measured using this sensing scheme. The sensitivity of this sensor must be improved to provide a simple, reliable, repeatable and non-destructive method for sensing various chemical gases. (technical design note)

  6. Magnetic graphene oxide modified with choline chloride-based deep eutectic solvent for the solid-phase extraction of protein

    International Nuclear Information System (INIS)

    Highlights: • A strategy for extraction of protein based on DES-coated magnetic graphene oxide. • The deep eutectic solvents were based on choline chloride. • Bovine serum albumin was used as the analyte. • The material prepared works for the acidic but not the basic or the neutral proteins. - Abstract: Four kinds of green deep eutectic solvents (DESs) based on choline chloride (ChCl) have been synthesized and coated on the surface of magnetic graphene oxide (Fe3O4@GO) to form Fe3O4@GO-DES for the magnetic solid-phase extraction of protein. X-ray diffraction (XRD), vibrating sample magnetometer (VSM), Fourier transform infrared spectrometry (FTIR), field emission scanning electron microscopy (FESEM) and thermal gravimetric analysis (TGA) were employed to characterize Fe3O4@GO-DES, and the results indicated the successful preparation of Fe3O4@GO-DES. The UV–vis spectrophotometer was used to measure the concentration of protein after extraction. Single factor experiments proved that the extraction amount was influenced by the types of DESs, solution temperature, solution ionic strength, extraction time, protein concentration and the amount of Fe3O4@GO-DES. Comparison of Fe3O4@GO and Fe3O4@GO-DES was carried out by extracting bovine serum albumin, ovalbumin, bovine hemoglobin and lysozyme. The experimental results showed that the proposed Fe3O4@GO-DES performs better than Fe3O4@GO in the extraction of acidic protein. Desorption of protein was carried out by eluting the solid extractant with 0.005 mol L−1 Na2HPO4 contained 1 mol L−1 NaCl. The obtained elution efficiency was about 90.9%. Attributed to the convenient magnetic separation, the solid extractant could be easily recycled

  7. Oxidation of Aliphatic Alcohols by Using Precious Metals Supported on Hydrotalcite under Solvent- and Base-Free Conditions.

    Science.gov (United States)

    He, Yufei; Feng, Junting; Brett, Gemma L; Liu, Yanan; Miedziak, Peter J; Edwards, Jennifer K; Knight, David W; Li, Dianqing; Hutchings, Graham J

    2015-10-12

    Precious metal nanoparticles supported on magnesium-aluminum hydrotalcite (HT), TiO2 , and MgO were prepared by sol immobilization and assessed for the catalytic oxidation of octanol, which is a relatively unreactive aliphatic alcohol, with molecular oxygen as the oxidant under solvent- and base-free conditions. Compared with the TiO2 - and MgO-supported catalysts, platinum HT gave the highest activity and selectivity towards the aldehyde. The turnover number achieved for the platinum HT catalyst was >3700 after 180 min under mild reaction conditions. Moreover, the results for the oxidation of different substrates indicate that a specific interaction of octanal with the platinum HT catalyst could lead to deactivation of the catalyst. PMID:26337897

  8. Electrochemical exfoliation of graphite in quaternary ammonium-based deep eutectic solvents: a route for the mass production of graphane.

    Science.gov (United States)

    Abdelkader, Amr M; Patten, Hollie V; Li, Zheling; Chen, Yiqiang; Kinloch, Ian A

    2015-07-14

    We demonstrate a facile and scalable electrochemical approach to exfoliate graphite, which permits in situ hydrogenation of the resultant graphene via a solvated NR(4+) graphite compound in quaternary ammonium-based deep eutectic solvents. Spectroscopic studies reveal the presence of sp(3) C-H bonds in the hydrogenated graphene. The resulting materials consist of micrometre-sized and predominantly monolayer to few layers thick hydrogenated graphenic flakes. A large band gap (∼4 eV) further establishes the high level of hydrogenation. It is also possible to tune the band gap introduced to the graphene by controlling the level of hydrogenation. The mechanism of the exfoliation and hydrogenation is also discussed. PMID:26074262

  9. Solvent-Dependent Self-Assembly of an Oxalato-Based Three-Dimensional Magnet Exhibiting a Novel Architecture.

    Science.gov (United States)

    Mon, Marta; Grancha, Thais; Verdaguer, Michel; Train, Cyrille; Armentano, Donatella; Pardo, Emilio

    2016-07-18

    The old but evergreen family of bimetallic oxalates still offers innovative and interesting results. When (Me4N)3[Cr(ox)3]·3H2O is reacted with Mn(II) ions in a nonaqueous solvent, a novel three-dimensional magnet of the formula [N(CH3)4]6[Mn3Cr4(ox)12]·6CH3OH is obtained instead of the one-dimensional compound obtained in water. This new material exhibits an unprecedented stoichiometry with a binodal (3,4) net topology and the highest critical temperature (TC = 7 K) observed so far in a manganese-chromium oxalate based magnet. PMID:27387762

  10. Solvent cleaning system and method for removing contaminants from solvent used in resin recycling

    Science.gov (United States)

    Bohnert, George W.; Hand, Thomas E.; DeLaurentiis, Gary M.

    2009-01-06

    A two step solvent and carbon dioxide based system that produces essentially contaminant-free synthetic resin material and which further includes a solvent cleaning system for periodically removing the contaminants from the solvent so that the solvent can be reused and the contaminants can be collected and safely discarded in an environmentally safe manner.

  11. Comparison of solvent and sacrificial volume-material-based lamination processes of low-temperature co-fired ceramics tapes

    Science.gov (United States)

    Malecha, Karol; Jurków, Dominik; Golonka, Leszek J.

    2009-06-01

    The lamination process determines the quality of low temperature co-fired ceramics (LTCC) based spatial structures. This paper compares two methods of the microchannel fabrication process in zero-shrinkage LTCC substrates. The first one is based on a two-step lamination process and uses various sacrificial volume materials (SVM). The second one is based on the cold chemical lamination (CCL) process. On the one hand, the SVM gives the possibility of decreasing the deformation of the three-dimensional (3D) structures during the lamination process. The channel volume is filled with a special fugitive material. It protects the spatial structure from deformation during lamination, and evaporates completely during the co-firing process. The bonding quality and strength depend strongly on the fugitive phase type. On the other hand, the CCL is a solvent-based method. It is another alternative for bonding of green ceramic tapes. A special liquid agent is screen printed on the green tape, which melts the tape surface. Then the tapes are stacked and compressed at room temperature by a printing roll. The influence of each method on the microchannel geometry is analyzed in this paper. The resulting structures' bonding quality and mechanical properties are examined by a scanning electron microscope (SEM).

  12. Bioavailability of Organic Solvents in Soils: Input into Biologically Based Dose-Response Models for Human Risk Assessments - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Webster, R. C.

    2000-10-01

    Compared to dermal exposures with neat or aqueous compound, little is understood about the dermal bioavailability of solvents in soil, dust, sludge, or sediment matrices. Therefore, research in this project was designed to provide an understanding of the influence of various environmental factors on the kinetics and bioavailability of solvent-laden soils.

  13. Colorimetric Humidity and Solvent Recognition Based on a Cation-Exchange Clay Mineral Incorporating Nickel(II)-Chelate Complexes.

    Science.gov (United States)

    Hosokawa, Hitoshi; Mochida, Tomoyuki

    2015-12-01

    Solvatochromic nickel(II) complexes with diketonato and diamine ligands were incorporated into a saponite clay by ion exchange, and their colorimetric humidity- and solvent-recognition properties were investigated. These powders exhibit color change from red to blue-green depending on humidity, and the detection range can be controlled by modifying the metal complex. The humidity response takes advantage of the humidity-dependent water content in clay and the coordination of water molecules to the metal complex in equilibrium. The addition of organic solvents to the powders causes a color change to occur, varying from red to blue-green depending on the donor number of the solvent, thereby enabling solvent recognition. In the clay, the affinity of less sterically hindered complexes to water or solvent molecules is decreased compared with that in solution because the cationic complexes interact with the anionic layers in the clay. Incorporating diethylene glycol into the materials produced thermochromic powders.

  14. Colorimetric Humidity and Solvent Recognition Based on a Cation-Exchange Clay Mineral Incorporating Nickel(II)-Chelate Complexes.

    Science.gov (United States)

    Hosokawa, Hitoshi; Mochida, Tomoyuki

    2015-12-01

    Solvatochromic nickel(II) complexes with diketonato and diamine ligands were incorporated into a saponite clay by ion exchange, and their colorimetric humidity- and solvent-recognition properties were investigated. These powders exhibit color change from red to blue-green depending on humidity, and the detection range can be controlled by modifying the metal complex. The humidity response takes advantage of the humidity-dependent water content in clay and the coordination of water molecules to the metal complex in equilibrium. The addition of organic solvents to the powders causes a color change to occur, varying from red to blue-green depending on the donor number of the solvent, thereby enabling solvent recognition. In the clay, the affinity of less sterically hindered complexes to water or solvent molecules is decreased compared with that in solution because the cationic complexes interact with the anionic layers in the clay. Incorporating diethylene glycol into the materials produced thermochromic powders. PMID:26542108

  15. Classification of the gasoline sample related to the adulteration with solvent based in a Principal Component Analysis (PCA) using FT-IR spectrometry; Classificacao de amostra de gasolina em relacao a adulteracao por solvente baseada na Analise de Componente Principal (PCA) usando espectrometria FT-IR

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Hilda Costa dos; Teixeira, Leonardo Sena Gomes [Universidade Salvador (UNIFACS), Salvador, BA (Brazil). Dept. de Engenharia e Arquitetura]. E-mail: hildac69@hotmail.com

    2003-07-01

    A descriptive and exploratory method to identify adulteration with solvent in samples of gasoline based on the principal component analysis (PCA) using FT-IR spectroscopy was developed. Oil diesel, kerosene, turpentine spirit and thinner were the solvents tested. The samples were added different amounts of solvent to the sample of gasoline type 'A' in way to maintain the alcohol concentration in 25%. After obtaining of the spectrum of infrared was made analysis of principal component using the program MATLAB. The results showed that it was possible to cluster samples of gasoline in different groups in agreement with the used solvent. Besides, samples previously analyzed at Universidade Salvador's laboratory, obeying conform criteria and no conform with the brazilian specifications, they were analyzed and classified as the presence or not of solvent, besides to inform which the solvent type used in the adulteration. (author)

  16. Deep catalytic oxidative desulfurization (ODS) of dibenzothiophene (DBT) with oxalate-based deep eutectic solvents (DESs).

    Science.gov (United States)

    Lü, Hongying; Li, Pengcheng; Deng, Changliang; Ren, Wanzhong; Wang, Shunan; Liu, Pan; Zhang, Han

    2015-07-01

    An oxalate-based DES with a tetrabutyl ammonium chloride and oxalate acid molar ratio of 1/2 (TBO1 : 2) exhibited high activity in oxidative desulfurization (ODS) of dibenzothiophene (DBT) under mild reaction conditions. It is potentially a promising and highly environmentally friendly approach for desulfurization of fuels. PMID:26051675

  17. Pulmonary Toxicity of Perfluorinated Silane-Based Nanofilm Spray Products: Solvent Dependency

    DEFF Research Database (Denmark)

    Nørgaard, Asger Wisti; Hansen, Jitka S.; Sørli, Jorid Birkelund;

    2014-01-01

    A number of cases of pulmonary injury by use of aerosolized surface coating products have been reported worldwide. The aerosol from a commercial alcohol-based nanofilm product (NFP) for coating of nonabsorbing surfaces was found to induce severe lung damage in a recent mouse bioassay. The NFP...

  18. Magnetic graphene oxide modified with choline chloride-based deep eutectic solvent for the solid-phase extraction of protein

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Yanhua; Wang, Yuzhi, E-mail: wyzss@hnu.edu.cn; Pan, Qi; Wang, Ying; Ding, Xueqin; Xu, Kaijia; Li, Na; Wen, Qian

    2015-06-02

    Highlights: • A strategy for extraction of protein based on DES-coated magnetic graphene oxide. • The deep eutectic solvents were based on choline chloride. • Bovine serum albumin was used as the analyte. • The material prepared works for the acidic but not the basic or the neutral proteins. - Abstract: Four kinds of green deep eutectic solvents (DESs) based on choline chloride (ChCl) have been synthesized and coated on the surface of magnetic graphene oxide (Fe{sub 3}O{sub 4}@GO) to form Fe{sub 3}O{sub 4}@GO-DES for the magnetic solid-phase extraction of protein. X-ray diffraction (XRD), vibrating sample magnetometer (VSM), Fourier transform infrared spectrometry (FTIR), field emission scanning electron microscopy (FESEM) and thermal gravimetric analysis (TGA) were employed to characterize Fe{sub 3}O{sub 4}@GO-DES, and the results indicated the successful preparation of Fe{sub 3}O{sub 4}@GO-DES. The UV–vis spectrophotometer was used to measure the concentration of protein after extraction. Single factor experiments proved that the extraction amount was influenced by the types of DESs, solution temperature, solution ionic strength, extraction time, protein concentration and the amount of Fe{sub 3}O{sub 4}@GO-DES. Comparison of Fe{sub 3}O{sub 4}@GO and Fe{sub 3}O{sub 4}@GO-DES was carried out by extracting bovine serum albumin, ovalbumin, bovine hemoglobin and lysozyme. The experimental results showed that the proposed Fe{sub 3}O{sub 4}@GO-DES performs better than Fe{sub 3}O{sub 4}@GO in the extraction of acidic protein. Desorption of protein was carried out by eluting the solid extractant with 0.005 mol L{sup −1} Na{sub 2}HPO{sub 4} contained 1 mol L{sup −1} NaCl. The obtained elution efficiency was about 90.9%. Attributed to the convenient magnetic separation, the solid extractant could be easily recycled.

  19. DFT-based simulations of IR amide I' spectra for a small protein in solution. Comparison of explicit and empirical solvent models.

    Science.gov (United States)

    Grahnen, Johan A; Amunson, Krista E; Kubelka, Jan

    2010-10-14

    Infrared (IR) amide I' spectra are widely used for investigations of the structural properties of proteins in aqueous solution. For analysis of the experimental data, it is necessary to separate the spectral features due to the backbone conformation from those arising from other factors, in particular the interaction with solvent. We investigate the effects of solvation on amide I' spectra for a small 40-residue helix-turn-helix protein by theoretical simulations based on density functional theory (DFT). The vibrational force fields and intensity parameters for the protein amide backbone are constructed by transfer from smaller heptaamide fragments; the side chains are neglected in the DFT calculations. Solvent is modeled at two different levels: first as explicit water hydrogen bonded to the surface amide groups, treated at the same DFT level, and, second, using the electrostatic map approach combined with molecular dynamics (MD) simulation. Motional narrowing of the spectral band shapes due to averaging over the fast solvent fluctuation is introduced by use of the time-averaging approximation (TAA). The simulations are compared with the experimental amide I', including two (13)C isotopically edited spectra, corrected for the side-chain signals. Both solvent models are consistent with the asymmetric experimental band shape, which arises from the differential solvation of the amide backbone. However, the effects of (13)C isotopic labeling are best captured by the gas-phase calculations. The limitations of the solvent models and implications for the theoretical simulations of protein amide vibrational spectra are discussed.

  20. Solvent-vapour treatment induced performance enhancement of amplified spontaneous emission based on poly[2-methoxy-5-(2/-ethyl-hexyloxy)-l,4-phenylene vinylene

    Institute of Scientific and Technical Information of China (English)

    Zhang Bo; Hou Yan-Bing; Teng Feng; Lou Zhi-Dong; Liu Xiao-Jun; Hu Bing; Wu Wen-Bin

    2011-01-01

    In this work, performance enhancements of amplified spontaneous emission (ASE) from poly[2-methoxy-5-(2'- ethyl-hexylaxy)-1,4-phenylene vinylene] (MEH-PPV) have been achieved via solvent vapour treatment. Correlations between the morphology of the film and the optical performance of polymer-based ASE are investigated. The active layers are characterised by atomic force microscopy and optical absorption. The results show that the solvent-vapour treatment can induce the MEH-PPV self-organisation into an ordered structure with a smooth surface, leading to enhanced optical gain. Thus the solvent-vapour treatment is a good method for improving the optical properties of the MEH-PPV.

  1. Solvent-Controlled Assembly of ionic Metal-Organic Frameworks Based on Indium and Tetracarboxylate Ligand: Topology Variety and Gas Sorption Properties

    KAUST Repository

    Zheng, Bing

    2016-07-15

    Four Metal-Organic Frameworks (MOFs) based on Indium and tetracarboxylate ligand have been synthesized through regulation of the solvent conditions, the resulted compounds not only exhibited rich structural topologies (pts, soc and unique topologies), but also interesting charge reversal framework features. By regulating the solvent, different building units (indium monomer, trimer) have been generated in situ, and they are connected with the ligand to form ionic frameworks 1-4, respectively. Among the synthesized four ionic frameworks, compounds 3 and 4 could keep their crystallinity upon heating temperature up to 300oC after fully removal of solvent guest molecules, they also exhibit the charge reversal framework features (3 adopts an overall cationic framework, while 4 has an anionic framework). Both compounds 3 and 4 exhibit significant uptake capacity for CO2 and H2, besides that, compounds 3 and 4 also present excellent selective adsorption of CO2 over N2 and CH4.

  2. The Effect of Temperature on Kinetics and Diffusion Coefficients of Metallocene Derivatives in Polyol-Based Deep Eutectic Solvents.

    Directory of Open Access Journals (Sweden)

    Laleh Bahadori

    Full Text Available The temperature dependence of the density, dynamic viscosity and ionic conductivity of several deep eutectic solvents (DESs containing ammonium-based salts and hydrogen bond donvnors (polyol type are investigated. The temperature-dependent electrolyte viscosity as a function of molar conductivity is correlated by means of Walden's rule. The oxidation of ferrocene (Fc/Fc+ and reduction of cobaltocenium (Cc+/Cc at different temperatures are studied by cyclic voltammetry and potential-step chronoamperometry in DESs. For most DESs, chronoamperometric transients are demonstrated to fit an Arrhenius-type relation to give activation energies for the diffusion of redox couples at different temperatures. The temperature dependence of the measured conductivities of DES1 and DES2 are better correlated with the Vogel-Tamman-Fulcher equation. The kinetics of the Fc/Fc+ and Cc+/Cc electrochemical systems have been investigated over a temperature range from 298 to 338 K. The heterogeneous electron transfer rate constant is then calculated at different temperatures by means of a logarithmic analysis. The glycerol-based DES (DES5 appears suitable for further testing in electrochemical energy storage devices.

  3. The Effect of Temperature on Kinetics and Diffusion Coefficients of Metallocene Derivatives in Polyol-Based Deep Eutectic Solvents.

    Science.gov (United States)

    Bahadori, Laleh; Chakrabarti, Mohammed Harun; Manan, Ninie Suhana Abdul; Hashim, Mohd Ali; Mjalli, Farouq Sabri; AlNashef, Inas Muen; Brandon, Nigel

    2015-01-01

    The temperature dependence of the density, dynamic viscosity and ionic conductivity of several deep eutectic solvents (DESs) containing ammonium-based salts and hydrogen bond donvnors (polyol type) are investigated. The temperature-dependent electrolyte viscosity as a function of molar conductivity is correlated by means of Walden's rule. The oxidation of ferrocene (Fc/Fc+) and reduction of cobaltocenium (Cc+/Cc) at different temperatures are studied by cyclic voltammetry and potential-step chronoamperometry in DESs. For most DESs, chronoamperometric transients are demonstrated to fit an Arrhenius-type relation to give activation energies for the diffusion of redox couples at different temperatures. The temperature dependence of the measured conductivities of DES1 and DES2 are better correlated with the Vogel-Tamman-Fulcher equation. The kinetics of the Fc/Fc+ and Cc+/Cc electrochemical systems have been investigated over a temperature range from 298 to 338 K. The heterogeneous electron transfer rate constant is then calculated at different temperatures by means of a logarithmic analysis. The glycerol-based DES (DES5) appears suitable for further testing in electrochemical energy storage devices. PMID:26642045

  4. Solvent extraction of base oil from used lubricant oil: a study on the performance of zeolite adsorption

    International Nuclear Information System (INIS)

    Solvent extraction is known as one of the potential techniques for recycling used lubricant oil. The recovered oil is identical to the virgin oil, but the oil maintains its darkish color and some odor. This paper is to study the performance of zeolite in removing color and odor. A part from the study, factorial design analysis indicated that the concentration of zeolite exerts to be the most influenced on the adsorption process in which the increase of zeolite concentration resulted in an average increase of 2.22% adsorption response. The number of contact stage appeared to be the second most influential effects, which brought an average increase of 1.38% adsorption response. Further more, it was found that the interaction between the concentration of zeolite and the number of contact stage was the most significant of all interactions under study, at 2.71%. Thus, the additions of 10 g zeolite in 50 ml base oil of 3rd stage color removal produces the best color removal from the recovered base oil. (Author)

  5. Solvent-assistant self-assembly of an AIE+TICT fluorescent Schiff base for the improved ammonia detection.

    Science.gov (United States)

    Han, Tianyu; Wei, Wei; Yuan, Jing; Duan, Yuai; Li, Yaping; Hu, Liangyu; Dong, Yuping

    2016-04-01

    Solvent-assistant self-assembly of an AIE+TICT fluorescent Schiff base into one-dimensional nanofilaments has been developed. The orientation of the assemblies can be controlled by a simple dewetting process: the filaments are interweaved when the self-assembly process is performed on a horizontal substrate, while tilting the substrate to a tiny angle results in the formation of highly oriented ones with long-range order as verified by microscopic examination. The compound shows remarkable fluorescent response to ammonia gas based on a TICT-LE transition. The self-assembled film presents higher detection sensitivity compared with the non-assembled test paper: the former enables 4.75 times faster response time and 6.86 times lower detection limit than the latter. Furthermore, the former demonstrates better selectivity toward ammonia gas in the presence of various organic amines. The sensing devices also enjoy the advantage of cyclic utilization. The fluorescence of the fumed devices can be converted back into the original state when they are heated at 100 °C for 5 min, as thermal treatment can desorb the ammonia gas that adsorbed in the sensing devices.

  6. Improved Cellulose and Organic-Solvents based Lignocellulosic Fractionation Pre-treatment of Organic Waste for Bioethanol Production

    Directory of Open Access Journals (Sweden)

    Valeriy Bekmuradov

    2014-06-01

    Full Text Available This study investigates the performance of the Cellulose and Organic-Solvents based Lignocellulosic Fractionation (COSLIF method for the pretreatment of Source-Separated Organic (SSO waste. An improvement on the standard method of COSLIF pre-treatment was developed based on lower enzyme loading and using an ethanol washing instead of acetone. It was demonstrated that a much higher glucose yield (90% after 72 hours was possible with this improvement, as compared to the original method, which yielded 70% in the same time frame. Evaluation of the enzymatic hydrolysate obtained from the modified COSLIF pretreatment was further examined by anaerobic fermentation with Zymomonas mobilis 8b strain. At 48 hours, ethanol concentration reached to 140 g/L, which is equivalent to 0.48 g of ethanol produced per gram of SSO biomass. This study demonstrated that the modified COSLIF pretreatment provides a substantial improvement over the standard method in terms of enzyme savings, glucose formation, and ethanol production.

  7. Solvent effect on H-bond cooperativity factors in ternary complexes of methanol, octan-1-ol, 2,2,2-trifluoroethanol with some bases

    Science.gov (United States)

    Solomonov, Boris N.; Varfolomeev, Mikhail A.; Abaidullina, Dilyara I.

    2008-03-01

    Cooperative hydrogen bonds in ternary complexes (ROH) 2⋯B (ROH—alcohols; B—bases) formed in pure bases (B) and solutions in n-hexane, carbon tetrachloride, benzene and 1,2-dichloroethane were studied by FTIR spectroscopy. Based on the observations, the authors were able to propose an original method of evaluating solvent effects on cooperativity factors in the complexes. Frequencies of cooperative hydrogen bonds OH⋯B ( νb) were determined for ternary complexes of pyridine with aliphatic alcohols (methanol, octan-1-ol) and for 2,2,2-trifluoroethanol with three different bases (acetonitrile, diethyl ether, tetrahydrofuran). The solvent shifts of νb were found to correlate with an empirical thermochemical parameter of the solvent, SVW. The cooperativity factors were determined for the complexes (ROH) 2⋯B in all studied media. It has been found that the cooperativity factors are almost independent of the solvent. In addition, a method was proposed of estimating the frequencies and cooperativity factors for ternary complexes (ROH) 2⋯B in the gas phase. It has been found that in gas phase the cooperativity factors are practically the same as in condensed media.

  8. Uranium from phosphoric acid: kinetics studies of the solvent extraction processes for separation based on statistical data analysis

    International Nuclear Information System (INIS)

    Uranium is recovered from wet process phosphoric acid, an important secondary source, by solvent extraction technique. Kinetics of the mass transfer processes involved in extraction, scrubbing and stripping, solvent recovery operations are important for process equipment design. In this investigation we have reported results on the kinetics of separation of entrained solvent by diluent washing. The effect of stirring speed, O/A ratio and temperature has been studied. Experiments at elevated temperature (45 deg C) were carried out by preheating the WPA and Petrofin and then mixing the required volume before stirring for different time periods. (author)

  9. Role of Chloride for a Simple, Non-Grignard Mg Electrolyte in Ether-Based Solvents.

    Science.gov (United States)

    Sa, Niya; Pan, Baofei; Saha-Shah, Anumita; Hubaud, Aude A; Vaughey, John T; Baker, Lane A; Liao, Chen; Burrell, Anthony K

    2016-06-29

    Mg battery operates with Chevrel phase (Mo6S8, ∼1.1 V vs Mg) cathodes that apply Grignard-based or derived electrolytes, which allow etching of the passivating oxide coating forms at the magnesium metal anode. Majority of Mg electrolytes studied to date are focused on developing new synthetic strategies to achieve a better reversible Mg deposition. While most of these electrolytes contain chloride as a component, and there is a lack of literature which investigates the fundamental role of chloride in Mg electrolytes. Further, ease of preparation and potential safety benefits have made simple design of magnesium electrolytes an attractive alternative to traditional air sensitive Grignard reagents-based electrolytes. Work presented here describes simple, non-Grignard magnesium electrolytes composed of magnesium bis(trifluoromethane sulfonyl)imide mixed with magnesium chloride (Mg(TFSI)2-MgCl2) in tetrahydrofuran (THF) and diglyme (G2) that can reversibly plate and strip magnesium. Based on this discovery, the effect of chloride in the electrolyte complex was investigated. Electrochemical properties at different initial mixing ratios of Mg(TFSI)2 and MgCl2 showed an increase of both current density and columbic efficiency for reversible Mg deposition as the fraction content of MgCl2 increased. A decrease in overpotential was observed for rechargeable Mg batteries with electrolytes with increasing MgCl2 concentration, evidenced by the coin cell performance. In this work, the fundamental understanding of the operation mechanisms of rechargeable Mg batteries with the role of chloride content from electrolyte could potentially bring rational design of simple Mg electrolytes for practical Mg battery. PMID:27255422

  10. Physical and chemical properties of nanoscale magnetite-based solvent extractant

    International Nuclear Information System (INIS)

    Nanoscale magnetite bearing magnetic carrier with an adsorbed layer of dibenzo-18-crown-6 was evaluated for removing radionuclides from nuclear waste solutions using magnetically assisted separation method. TEM results indicate that the average size of the base magnetite particles is ∼19 nm. The results of Moessbauer spectroscopy and field cooled (FC) and zero field cooled (ZFC) magnetization confirm the superparamagnetic behaviour of the magnetite particles in the polymer beads at room temperature and hence meet the requirement of magnetic filter regeneration capability

  11. Electroplated Fe-Co-Ni films prepared from deep-eutectic-solvent-based plating baths

    Science.gov (United States)

    Yanai, Takeshi; Shiraishi, Kotaro; Akiyoshi, Toshiki; Azuma, Keita; Watanabe, Yoshimasa; Ohgai, Takeshi; Morimura, Takao; Nakano, Masaki; Fukunaga, Hirotoshi

    2016-05-01

    We fabricated soft magnetic films from DES-based plating baths, and investigated magnetic properties of the plated films. The plating baths were obtained by stirring the mixture of choline chloride, ethylene glycol, FeCl2 ṡ 4H2O, NiCl2 ṡ 6H2O and CoCl2 ṡ 6H2O. The composition of the electroplated film depended on the amount of the reagent in the plating bath, and we consequently obtained the films with various composition. The current efficiency of the plating process shows high values (> 88 %) in the wide composition range. The soft magnetic films with low coercivity were obtained at the Fe compositions of ≈ 30 at.% and > 80 at.%, and we found that low coercivity could be realized by the control of the film composition. We also found that the Fe-rich films prepared from DES-based plating bath have some advantages as a soft magnetic phase for a nanocomposite magnet due to their high saturation magnetization and very fine crystal structure.

  12. Electroplated Fe-Co-Ni films prepared from deep-eutectic-solvent-based plating baths

    Directory of Open Access Journals (Sweden)

    Takeshi Yanai

    2016-05-01

    Full Text Available We fabricated soft magnetic films from DES-based plating baths, and investigated magnetic properties of the plated films. The plating baths were obtained by stirring the mixture of choline chloride, ethylene glycol, FeCl2 ⋅ 4H2O, NiCl2 ⋅ 6H2O and CoCl2 ⋅ 6H2O. The composition of the electroplated film depended on the amount of the reagent in the plating bath, and we consequently obtained the films with various composition. The current efficiency of the plating process shows high values (> 88 % in the wide composition range. The soft magnetic films with low coercivity were obtained at the Fe compositions of ≈ 30 at.% and > 80 at.%, and we found that low coercivity could be realized by the control of the film composition. We also found that the Fe-rich films prepared from DES-based plating bath have some advantages as a soft magnetic phase for a nanocomposite magnet due to their high saturation magnetization and very fine crystal structure.

  13. A simple model for solute-solvent separation through nanopores based on core-softened potentials

    Science.gov (United States)

    de Vasconcelos, Cláudia K. B.; Batista, Ronaldo J. C.; da Rocha Régis, McGlennon; Manhabosco, Taíse M.; de Oliveira, Alan B.

    2016-07-01

    We propose an effective model for solute separation from fluids through reverse osmosis based on core-softened potentials. Such potentials have been used to investigate anomalous fluids in several situations under a great variety of approaches. Due to their simplicity, computational simulations become faster and mathematical treatments are possible. Our model aims to mimic water desalination through nano-membranes through reverse osmosis, for which we have found reasonable qualitative results when confronted against all-atoms simulations found in the literature. The purpose of this work is not to replace any fully atomistic simulation at this stage, but instead to pave the first steps towards coarse-grained models for water desalination processes. This may help to approach problems in larger scales, in size and time, and perhaps make analytical theories more viable.

  14. A Selenium-Based Ionic Liquid as a Recyclable Solvent for the Catalyst-Free Synthesis of 3-Selenylindoles

    Directory of Open Access Journals (Sweden)

    Eder J. Lenardão

    2013-04-01

    Full Text Available The ionic liquid 1-butyl-3-methylimidazolium methylselenite, [bmim][SeO2(OCH3], was successfully used as solvent in the catalyst-free preparation of 3-arylselenylindoles by the reaction of indole with ArSeCl at room temperature. The products were obtained selectively in good yields without the need of any additive and the solvent was easily reused for several cycles with good results.

  15. Study of gold nanoparticles effect on thermal diffusivity of nanofluids based on various solvents by using thermal lens spectroscopy

    Science.gov (United States)

    Jiménez Pérez, J. L.; Gutierrez Fuentes, R.; Sanchez Ramirez, J. F.; Cruz-Orea, A.

    2008-01-01

    Dual beam thermal lens technique is used to determine the thermal diffusivity of different solvents in presence of gold nanoparticles. In this technique an Ar+ laser (wavelength 514 nm, power 40 mW) and intensity stabilized He-Ne laser were used as the heating source and probe beam respectively. The experimental results showed that thermal diffusivity values of the studied solvents (water, ethanol and ethylene glycol (EG)) were enhanced by the presence of gold nanoparticles.

  16. Non-flammable electrolytes based on trimethyl phosphate solvent for lithium-ion batteries

    Institute of Scientific and Technical Information of China (English)

    HU Chuan-yue; LI Xin-hai

    2005-01-01

    The properties of trimethyl phosphate(TMP)-based nonflammable electrolytes with LiPF6 as solute were investigated using graphite anode and LiCoO2 cathode. The effect of TMP on non-flammability of electrolytes was also evaluated. It is found that the TMP reduction decomposition on graphite electrode at the potential of 1.3V (vs Li/Li+) is suppressed with ethylene carbonate(EC), dimethyl carbonate(DMC) and ethylmethyl carbonate(EMC) cosolvents and vinylene carbonate(VC) additives. The results show that the non-flammable electrolyte of 1mol/L LiPF6 61%(EC1.5-DMC1.0-EMC1.0)-39% TMP has good electrochemical properties. The discharge capacities of half-cells after 20 cycles are 254.8mA·h/g for Li/graphite and 144.1mA·h/g for Li/LiCoO2. The graphite/LiCoO2 prismatic lithium-ion cell delivers a discharge capacity of 131mA·h/g at first cycle. With an addition of 4%VC to this non-flammable electrolyte, a discharge capacity of 134mA·h/g at first cycle and a capacity ratio of 84.3% after 50 cycles are obtained for prismatic lithium-ion batteries. Furthermore, a nail penetration test demonstrates that the safety of prismatic lithium-ion batteries is dramatically improved by using TMP-containing non-flammable electrolytes.

  17. Optical sensor based on hybrid FBG/titanium dioxide coated LPFG for monitoring organic solvents in edible oils.

    Science.gov (United States)

    Coelho, Luís; Viegas, Diana; Santos, José Luís; de Almeida, José Manuel Marques Martins

    2016-01-01

    A hybrid optical sensing scheme based on a fiber Bragg grating (FBG) combined with a titanium dioxide coated long period fiber grating (LPFG) for monitoring organic solvents in high refractive index edible oils is reported. In order to investigate and optimize the sensor performance, two different FBG/LPFG interrogation systems were investigated. The readout of the sensor was implemented using either the wavelength shift of the LPFG resonance dip or the variation in the optical power level of the reflected/transmitted light at the FBG wavelength peak, which in turn depends on the wavelength position of the LPFG resonance. Hexane concentrations up to 20%V/V, corresponding to the refractive index range from 1.451 to 1.467, were considered. For the transmission mode of operation, sensitivities of 1.41 nm/%V/V and 0.11 dB/%V/V, with resolutions of 0.58%V/V and 0.29%V/V, were achieved when using the LPFG wavelength shift and the FBG transmitted optical power, respectively. For the FBG reflection mode of operation, a sensitivity of 0.07 dB/%V/V and a resolution better than 0.16%V/V were estimated.

  18. Optical sensor based on hybrid FBG/titanium dioxide coated LPFG for monitoring organic solvents in edible oils.

    Science.gov (United States)

    Coelho, Luís; Viegas, Diana; Santos, José Luís; de Almeida, José Manuel Marques Martins

    2016-02-01

    A hybrid optical sensing scheme based on a fiber Bragg grating (FBG) combined with a titanium dioxide coated long period fiber grating (LPFG) for monitoring organic solvents in high refractive index edible oils is reported. In order to investigate and optimize the sensor performance, two different FBG/LPFG interrogation systems were investigated. The readout of the sensor was implemented using either the wavelength shift of the LPFG resonance dip or the variation in the optical power level of the reflected/transmitted light at the FBG wavelength peak, which in turn depends on the wavelength position of the LPFG resonance. Hexane concentrations up to 20%V/V, corresponding to the refractive index range from 1.451 to 1.467, were considered. For the transmission mode of operation, sensitivities of 1.41 nm/%V/V and 0.11 dB/%V/V, with resolutions of 0.58%V/V and 0.29%V/V, were achieved when using the LPFG wavelength shift and the FBG transmitted optical power, respectively. For the FBG reflection mode of operation, a sensitivity of 0.07 dB/%V/V and a resolution better than 0.16%V/V were estimated. PMID:26653438

  19. Development of an Analytical Method Based on Temperature Controlled Solid-Liquid Extraction Using an Ionic Liquid as Solid Solvent

    Directory of Open Access Journals (Sweden)

    Zhongwei Pan

    2015-12-01

    Full Text Available At the present paper, an analytical method based on temperature controlled solid-liquid extraction (TC-SLE utilizing a synthesized ionic liquid, (N-butylpyridinium hexafluorophosphate, [BPy]PF6, as solid solvent and phenanthroline (PT as an extractant was developed to determine micro levels of Fe2+ in tea by PT spectrophotometry. TC-SLE was carried out in two continuous steps: Fe2+ can be completely extracted by PT-[BPy]PF6 or back-extracted at 80 °C and the two phases were separated automatically by cooling to room temperature. Fe2+, after back-extraction, needs 2 mol/L HNO3 as stripping agent and the whole process was determined by PT spectrophotometry at room temperature. The extracted species was neutral Fe(PTmCl2 (m = 1 according to slope analysis in the Fe2+-[BPy]PF6-PT TC-SLE system. The calibration curve was Y = 0.20856X − 0.000775 (correlation coefficient = 0.99991. The linear calibration range was 0.10–4.50 μg/mL and the limit of detection for Fe2+ is 7.0 × 10−2 μg/mL. In this method, the contents of Fe2+ in Tieguanyin tea were determined with RSDs (n = 5 3.05% and recoveries in range of 90.6%–108.6%.

  20. Water-in-ionic liquid microemulsion formation in solvent mixture of aprotic and protic imidazolium-based ionic liquids.

    Science.gov (United States)

    Kusano, Takumi; Fujii, Kenta; Hashimoto, Kei; Shibayama, Mitsuhiro

    2014-10-14

    We report that water-in-ionic liquid microemulsions (MEs) are stably formed in an organic solvent-free system, i.e., a mixture of aprotic (aIL) and protic (pIL) imidazolium-based ionic liquids (ILs) containing the anionic surfactant dioctyl sulfosuccinate sodium salt (AOT). Structural investigations using dynamic light, small-angle X-ray, and small-angle neutron scatterings were performed for MEs formed in mixtures of aprotic 1-octyl-3-methylimidazolium ([C8mIm(+)]) and protic 1-alkylimidazolium ([CnImH(+)], n = 4 or 8) IL with a common anion, bis(trifluoromethanesulfonyl)amide ([TFSA(-)]). It was found that the ME structure strongly depends on the mixing composition of the aIL/pIL in the medium. The ME size appreciably increases with increasing pIL content in both [C8mIm(+)][TFSA(-)]/[C8ImH(+)][TFSA(-)] and [C8mIm(+)][TFSA(-)]/[C4ImH(+)][TFSA(-)] mixtures. The size is larger for the n = 8 system than that for the n = 4 system. These results indicate that the shell part of MEs is composed of both AOT and pIL cation, and the ME size can be tuned by pIL content in the aIL/pIL mixtures. PMID:25226398

  1. Experimental study of solvent-based emulsion injection to enhance heavy oil recovery in Alaska North Slope area

    Energy Technology Data Exchange (ETDEWEB)

    Qiu, F.; Mamora, D. [Texas A and M Univ., College Station, TX (United States)

    2010-07-01

    This study examined the feasibility of using a chemical enhanced oil recovery method to overcome some of the technical challenges associated with thermal recovery in the Alaska North Slope (ANS). This paper described the second stage research of an experimental study on nano-particle and surfactant-stabilized solvent-based emulsions for the ANS area. Four successful core flood experiments were performed using heavy ANS oil. The runs included water flooding followed by emulsion flooding; and pure emulsion injection core flooding. The injection rate and core flooding temperature remained constant and only 1 PV micro-emulsion was injected after breakthrough under water flooding or emulsion flooding. Oil recovery increased by 26.4 percent from 56.2 percent original oil in place (OOIP) with waterflooding to 82.6 percent OOIP with injection of emulsion following water flooding. Oil recovery was slightly higher with pure emulsion flooding, at 85.8 percent OOIP. The study showed that low permeability generally resulted in a higher shear rate, which is favourable for in-situ emulsification and higher displacement efficiency. 11 refs., 4 tabs., 20 figs.

  2. Mechanical and barrier properties of starch-based films plasticized with two- or three component deep eutectic solvents.

    Science.gov (United States)

    Zdanowicz, Magdalena; Johansson, Caisa

    2016-10-20

    The aim of this work was to prepare two- and three-components deep eutectic solvents (DES) and investigate their potential as starch plasticizers. Starch/DES films were prepared via casting method. Mechanical properties, water vapor- and oxygen transmission rates were measured; additionally contact angle and moisture sorption were determined and FTIR analysis was applied on the films. Native potato starch and hydroxypropylated and oxidized starch (HOPS) with common plasticizers (e.g. polyols, urea) and DES were studied. Moreover, influence of three methods of DES introduction and concentration of plasticizer on the films properties were compared. HOPS films were prepared by two methods: as non-cured and cured samples. Some of DESs containing citrate anion exhibited crosslinking ability of polysaccharide matrix. Non-cured HOPS/DES films exhibited more favourable mechanical and barrier properties than cured analogue films. Samples prepared with unmodified potato starch had higher mechanical and barrier properties than films made with HOPS. Starch-based films plasticized with novel DESs with parallel crosslinking activity exhibited satisfactory mechanical and barrier properties. PMID:27474548

  3. Reversible structural transformations in a Co(II)-based 2D dynamic metal-organic framework showing selective solvent uptake

    Indian Academy of Sciences (India)

    Sanjog S Nagarkar; Sujit K Ghosh

    2015-04-01

    A Co(II)-based two-dimensional (2D) metal-organic framework (MOF) [Co(pca)(bdc)0.5(H2O)2] (1) {pca = pyrazine carboxylic acid, and bdc = 1,4-benzene dicarboxylic acid} was synthesized solvothermally. The compound loses the coordinated lattice water molecules on heating which is accompanied by solidstate structural transformation to yield dehydrated phase [Co(pca)(bdc)0.5] (1′). The hydrated structure can be regained by exposing 1′ to water vapour (1′′). These reversible solid-state structural transformations are accompanied by a visible colour change in the material. The dehydrated compound also shows highly selective water uptake over other solvents like MeOH, EtOH, THF. This selective water uptake can be ascribed to the high affinity of polar water molecule towards the open metal site created on heating. The present report provides important insights into the reversible structural transformations observed due to variable coordination number of the central metal ion and transformability of the framework. The selective water uptake over alcohols along with visible colour change demonstrates the potential of the present compound in bio-alcohol purification.

  4. G-quadruplex DNA-based asymmetric catalysis of michael addition: Effects of sonication, ligands, and co-solvents.

    Science.gov (United States)

    Zhao, Hua; Shen, Kai

    2016-07-01

    There is an escalating interest of using double stranded DNA molecules as a chiral scaffold to construct metal-biomacromolecule hybrid catalysts for asymmetric synthesis. Several recent studies also evaluated the use of G-quadruplex DNA-based catalysts for asymmetric Diels-Alder and Friedel-Crafts reactions. However, there is still a lack of understanding of how different oligonucleotides, salts (such as NaCl and KCl), metal ligands and co-solvents affect the catalytic performance of quadruplex DNA-based hybrid catalysts. In this study, we aim to systematically evaluate these key factors in asymmetric Michael addition reactions, and to examine the conformational and molecular changes of DNA by circular dichroism (CD) spectroscopy and gel electrophoresis. We achieved up to 95% yield and 50% enantiomeric excess (ee) when the reaction of 2-acylimidazole 1a and dimethylmalonate was catalyzed by 5'-G3 (TTAG3 )3 -3' (G4DNA1) in 20 mM MOPS (pH 6.5) containing 50 mM KCl and 40 µM [Cu(dmbipy)(NO3 )2 ], and G4DNA1 was pre-sonicated in ice bath for 10 min prior to the reaction. G-quadruplex-based hybrid catalysts provide a new tool for asymmetric catalysis, but future mechanistic studies should be sought to further improve the catalytic efficiency. The current work presents a systematic study of asymmetric Michael addition catalyzed by G-quadruplex catalysts constructed via non-covalent complexing, and an intriguing finding of the effect of pre-sonication on catalytic efficiency. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:891-898, 2016. PMID:27090055

  5. Reactions and Separations in Green Solvents

    NARCIS (Netherlands)

    Van Spronsen, J.

    2010-01-01

    Most chemical processes involve solvents in the reaction and the separation step. These solvents give rise to a heavy environmental and economical burden. Moreover, these solvents are based on non-sustainable resources like petroleum. The aim of this thesis has been to develop a number of alternativ

  6. THz frequency spectrum of protein-solvent interaction energy using a recurrence plot-based Wiener-Khinchin method.

    Science.gov (United States)

    Karain, Wael

    2016-10-01

    The dynamics of a protein and the water surrounding it are coupled via nonbonded energy interactions. This coupling can exhibit a complex, nonlinear, and nonstationary nature. The THz frequency spectrum for this interaction energy characterizes both the vibration spectrum of the water hydrogen bond network, and the frequency range of large amplitude modes of proteins. We use a Recurrence Plot based Wiener-Khinchin method RPWK to calculate this spectrum, and the results are compared to those determined using the classical auto-covariance-based Wiener-Khinchin method WK. The frequency spectra for the total nonbonded interaction energy extracted from molecular dynamics simulations between the β-Lactamase Inhibitory Protein BLIP, and water molecules within a 10 Å distance from the protein surface, are calculated at 150, 200, 250, and 310 K, respectively. Similar calculations are also performed for the nonbonded interaction energy between the residues 49ASP, 53TYR, and 142PHE in BLIP, with water molecules within 10 Å from each residue respectively at 150, 200, 250, and 310 K. A comparison of the results shows that RPWK performs better than WK, and is able to detect some frequency data points that WK fails to detect. This points to the importance of using methods capable of taking the complex nature of the protein-solvent energy landscape into consideration, and not to rely on standard linear methods. In general, RPWK can be a valuable addition to the analysis tools for protein molecular dynamics simulations. Proteins 2016; 84:1549-1557. © 2016 Wiley Periodicals, Inc.

  7. Solvent-resistant organic transistors and thermally stable organic photovoltaics based on cross-linkable conjugated polymers

    KAUST Repository

    Kim, Hyeongjun

    2012-01-10

    Conjugated polymers, in general, are unstable when exposed to air, solvent, or thermal treatment, and these challenges limit their practical applications. Therefore, it is of great importance to develop new materials or methodologies that can enable organic electronics with air stability, solvent resistance, and thermal stability. Herein, we have developed a simple but powerful approach to achieve solvent-resistant and thermally stable organic electronic devices with a remarkably improved air stability, by introducing an azide cross-linkable group into a conjugated polymer. To demonstrate this concept, we have synthesized polythiophene with azide groups attached to end of the alkyl chain (P3HT-azide). Photo-cross-linking of P3HT-azide copolymers dramatically improves the solvent resistance of the active layer without disrupting the molecular ordering and charge transport. This is the first demonstration of solvent-resistant organic transistors. Furthermore, the bulk-heterojunction organic photovoltaics (BHJ OPVs) containing P3HT-azide copolymers show an average efficiency higher than 3.3% after 40 h annealing at an elevated temperature of 150 °C, which represents one of the most thermally stable OPV devices reported to date. This enhanced stability is due to an in situ compatibilizer that forms at the P3HT/PCBM interface and suppresses macrophase separation. Our approach paves a way toward organic electronics with robust and stable operations. © 2011 American Chemical Society.

  8. Solvent effects on modulus of poly(propylene oxide)-based organogels as measured by cavitation rheology.

    Science.gov (United States)

    Bentz, Kyle C; Walley, Susan E; Savin, Daniel A

    2016-06-14

    A series of novel organogels were synthesized from poly(propylene oxide) (PPO) functionalized with main chain urea moieties which provided rapid gelation and high moduli in a variety of solvents. Three different molecular weight PPOs were used in this study: 430, 2000, and 4000 g mol(-1), each with α,ω-amino-end groups. Four urea groups were introduced into the main chain by reaction with hexamethylene diisocyanate followed by subsequent reaction with a monofunctional alkyl or aromatic amine. This PPO/urea gelator was found to form gels in carbon tetrachloride, chloroform, dichloromethane, toluene, ethyl acetate, and tetrahydrofuran. Among these, carbon tetrachloride and toluene were found to be the best solvents for this system, resulting in perfectly clear gels with high moduli at low mass fraction for PPO-2000 systems. Flory-Huggins polymer-solvent interaction parameter, χ, was found to be a useful indicator of gel quality for these systems, with χCCl4/PPO-2000 0.5 were found to form low moduli gels, indicating that for these systems, polymer-solvent interaction parameters can be a useful predictor of gel quality in different solvent systems. PMID:27181162

  9. Spectroscopic, solvent influence and thermal studies of ternary copper(II) complexes of diester and dinitrogen base ligands.

    Science.gov (United States)

    Emara, Adel A A; Abu-Hussein, Azza A A; Taha, Ahmed A; Mahmoud, Nelly H

    2010-10-15

    New mixed-ligand copper(II) complexes containing the bidentate dinitrogen ligands [N,N,N',N'-tetramethylethylenediamine (tmen), 2,2'-bipyridine (bipy) and 1,10-phenanthroline (phen)] and the bidentate dioxygen ligands [diethylmalonate (DEM), ethylacetoacetate (EAA) and ethylbenzoylacetate (EBA)] were prepared. The complexes were characterized by elemental analysis, infrared, mass and ESR spectral data, magnetic and molar conductance measurements and thermal gravimetric analysis. From the investigation, the geometries of the complexes are square planar for perchlorate complexes and a square pyramid or octahedral for the nitrate complexes. Solvatochromic behavior of the Cu(II) complexes indicates strong solvatochromism of their solutions in polar and non-polar solvents. The observed solvatochromism is due to the solute-solvent interaction between the chelate cation and the solvent molecules. PMID:20688561

  10. Spectroscopic, solvent influence and thermal studies of ternary copper(II) complexes of diester and dinitrogen base ligands

    Science.gov (United States)

    Emara, Adel A. A.; Abu-Hussein, Azza A. A.; Taha, Ahmed A.; Mahmoud, Nelly H.

    2010-10-01

    New mixed-ligand copper(II) complexes containing the bidentate dinitrogen ligands [ N,N,N',N'-tetramethylethylenediamine (tmen), 2,2'-bipyridine (bipy) and 1,10-phenanthroline (phen)] and the bidentate dioxygen ligands [diethylmalonate (DEM), ethylacetoacetate (EAA) and ethylbenzoylacetate (EBA)] were prepared. The complexes were characterized by elemental analysis, infrared, mass and ESR spectral data, magnetic and molar conductance measurements and thermal gravimetric analysis. From the investigation, the geometries of the complexes are square planar for perchlorate complexes and a square pyramid or octahedral for the nitrate complexes. Solvatochromic behavior of the Cu(II) complexes indicates strong solvatochromism of their solutions in polar and non-polar solvents. The observed solvatochromism is due to the solute-solvent interaction between the chelate cation and the solvent molecules.

  11. A Risk-Based Decision tool to support remediation decision-making for groundwater contaminated with chlorinated solvents

    International Nuclear Information System (INIS)

    Selection of remediation alternatives for large groundwater plumes containing chlorinated solvents are often complex and difficult, in part because they involve competing objectives, e.g. reduction of health risk vs. increased cost. The Department of Energy (DOE) supported development of a Decision Tool to provide a risk-based process for evaluating and comparing remedial options fairly and consistently. The Decision Tool is also intended to provide a process for constructive discussion of alternatives among the appropriate stakeholders. To use the Decision Tool, which is implemented in an Excel spreadsheet, a site manager must evaluate each alternative being considered against six objectives using detailed performance metrics. The impacts of each alternative on the individual objectives are combined through a formal multi-attribute utility analysis. Predetermined or user-specified relative weights for the objectives can be used, and a variety of visual outputs are generated. The usefulness and validity of the Decision Tool was demonstrated through a Pilot Study application for the A-Area Burning Rubble Pits/Miscellaneous Chemical Basin groundwater plume at the DOE Savannah River Site. The Pilot Study results provided a new perspective on the alternatives and objectives by demonstrating: 1) the relatively small public health risks associated with groundwater contamination at this site, 2) that more active approaches had benefits over monitored natural attenuation (MNA) in reducing time required to meet the maximum contaminant level (MCL) and maximizing regulatory responsiveness, 3) that MNA has acceptable public and worker health and safety risks, while enabling a reduction in costs. Use of the Decision Tool also promoted valuable discussion among the various stakeholders, and provided options for sensitivity analyses that can quickly be visualized to assess relative benefits of each of the alternatives. (authors)

  12. HMM-based prediction for protein structural motifs' two local properties: solvent accessibility and backbone torsion angles.

    Science.gov (United States)

    Yu, Jianyong; Xiang, Leijun; Hong, Jiang; Zhang, Weidong

    2013-02-01

    Protein structure prediction is often assisted by predicting one-dimensional structural properties including relative solvent accessibility (RSA) surface and backbone torsion angles (BTA) of residues, and these two properties are continuously varying variables because proteins can move freely in a three-dimensional space. Instead of subdividing them into a few arbitrarily defined states that many popular approaches used, this paper proposes an integrated system for realvalue prediction of protein structural motifs' two local properties, based on the modified Hidden Markov Model that we previously presented. The model was used to capture the relevance of RSA and the dependency of BTA between adjacent residues along the local protein chain in motifs with definite probabilities. These two properties were predicted according to their own probability distribution. The method was applied to a protein fragment library. For nine different classes of motifs, real values of RSA were predicted with mean absolute error (MAE) of 0.122-0.175 and Pearson's correlation coefficient (PCC) of 0.623-0.714 between predicted and actual RSA. Meanwhile, real values of BTA were obtained with MAE of 8.5⁰-29.4⁰ for Φ angles, 11.2⁰-38.5⁰ for ψ angles and PCC of 0.601-0.716 for Φ, 0.597-0.713 for ψ. The results were compared with well-known Real-SPINE Server, and indicate the proposed method may at least serve as the foundation to obtain better local properties from structural motifs for protein structure prediction. PMID:22894152

  13. Infrared and vibrational CD spectra of partially solvated alpha-helices: DFT-based simulations with explicit solvent.

    Science.gov (United States)

    Turner, David R; Kubelka, Jan

    2007-02-22

    Theoretical simulations are used to investigate the effects of aqueous solvent on the vibrational spectra of model alpha-helices, which are only partly exposed to solvent to mimic alpha-helices in proteins. Infrared absorption (IR) and vibrational circular dichroism (VCD) amide I' spectra for 15-amide alanine alpha-helices are simulated using density functional theory (DFT) calculations combined with the property transfer method. The solvent is modeled by explicit water molecules hydrogen bonded to the solvated amide groups. Simulated spectra for two partially solvated model alpha-helices, one corresponding to a more exposed and the other to a more buried structure, are compared to the fully solvated and unsolvated (gas phase) simulations. The dependence of the amide I spectra on the orientation of the partially solvated helix with respect to the solvent and effects of solvation on the amide I' of 13C isotopically substituted alpha-helices are also investigated. The partial exposure to solvent causes significant broadening of the amide I' bands due to differences in the vibrational frequencies of the explicitly solvated and unsolvated amide groups. The different degree of partial solvation is reflected primarily in the frequency shifts of the unsolvated (buried) amide group vibrations. Depending on which side of the alpha-helix is exposed to solvent, the simulated IR band-shapes exhibit significant changes, from broad and relatively featureless to distinctly split into two maxima. The simulated amide I' VCD band-shapes for the partially solvated alpha-helices parallel the broadening of the IR and exhibit more sign variation, but generally preserve the sign pattern characteristic of the alpha-helical structures and are much less dependent on the alpha-helix orientation with respect to the solvent. The simulated amide I' IR spectra for the model peptides with explicitly hydrogen-bonded water are consistent with the experimental data for small alpha-helical proteins

  14. Green oxidation of alkenes in ionic liquid solvent by hydrogen peroxide over high performance Fe(III) Schiff base complexes immobilized on MCM-41

    Indian Academy of Sciences (India)

    Mohammad Taghi Goldani; Ali Mohammadi; Reza Sandaroos

    2014-05-01

    A series of Fe(III) Schiff base complexes immobilized on MCM-41 were prepared and characterized by various physicochemical and spectroscopic methods. The complexes were used for oxidation of cyclohexene by 30% hydrogen peroxide in the presence and absence of ethylmethyl imidazolium chloride (EMIM) ionic liquid as solvent. The immobilized complexes proved to be effective catalysts and generally exhibited much higher catalytic performance than their homogeneous analogue. Catalytic performance of the complexes was also found to be closely related to the Schiff base ligands used. Additionally, ion liquid solvent efficiently improved all the catalytic performances. Finally, the reaction was extended to different alkenes using the heterogeneous complex 2-L4. Among all the alkenes, those containing -electron-withdrawing groups and trans-orientations exhibited lower tendency for oxidation.

  15. Synthesis of (E)-2-Styrylchromones and Flavones by Base-Catalyzed Cyclodehydration of the Appropriate β-Diketones Using Water as Solvent

    OpenAIRE

    Joana Pinto; Vera L. M. Silva; Ana M. G. Silva; Silva, Artur M. S.

    2015-01-01

    A low cost, safe, clean and environmentally benign base-catalyzed cyclodehydration of appropriate β-diketones affording (E)-2-styrylchromones and flavones in good yields is disclosed. Water was used as solvent and the reactions were heated using classical and microwave heating methods, under open and closed vessel conditions. β-Diketones having electron-donating and withdrawing substituents were used to evaluate the reaction scope. The reaction products were isolated in high purity by simple ...

  16. Computer Aided Solvent Selection and Design Framework

    DEFF Research Database (Denmark)

    Mitrofanov, Igor; Conte, Elisa; Abildskov, Jens;

    Solvents are widely used as a reaction medium, as a reactant or as carrier at some stages of the manufacturing chain in products from the chemical, fine chemical, pharmaceutical, food, and agrochemical industries. Solvent are either required for processing after which they are removed...... is to develop a systematic framework and implement it as software for selection and design of solvents for many applications including organic synthesis, complex reaction systems and solvent-based separations. The solvent selection framework is based on a combination of knowledge from industrial practice...... for each reaction: 1. Problem identification. Finding an objective for given system, identifying actual functions of the solvent. 2. Search criteria definition. The solvent functions that satisfy the operational needs of the process are defined in terms of a set of search criteria (R-indices), defined...

  17. Effects of residual water on microtensile bond strength of one-bottle dentin adhesive systems with different solvent bases

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhi-xing; HUANG Cui; ZHENG Tie-li; WANG Sa; CHENG Xiang-rong

    2005-01-01

    Background The wet-bonding technique is recommended for the one-bottle dentin adhesive systems, but the moisture concept varies widely among the instructions of manufacturers as well as among investigators. The aim of this study was to evaluate the effects of different dentin surface moisture on the microtensile bond strength(s) of an ethanol/water-based adhesive system and an acetone-based system to dentin. Methods Forty intact human premolars extracted for orthodontic reasons were used. Superficial occlusal flat dentin surfaces of these premolars were exposed, finished with wet 600-grit silicon carbide paper. Under four wet and dry conditions (overwet, blot dry, one-second dry and desiccated), resin composite was bonded to dentin by using Single Bond (SB) or Prime & Bond NT (PB) according to the manufacturers' instructions. The teeth were longitudinally sectioned in the "x" and "y" directions to obtain bonded beams with a cross-sectional area of 0.81 mm2 with a slow-speed diamond saw. The bonded specimens were tested in tension at a crosshead speed of 1 mm/min until failure of the bonds. Failure modes were observed with a scanning electron microscope. The mean bond strengths were analyzed by one-way ANOVA and Turkey's test. Results The bond strength of the overwet/SB, blot dry/SB, one-second dry/SB and desiccated/SB groups was 10.87 Mpa, 22.47 Mpa, 24.91 Mpa and 12.99 Mpa, respectively. The bond strength of the overwet/PB, blot dry/PB, one-second dry/PB and desiccated/PB groups was 10.02 Mpa, 20.67 Mpa, 21.82 Mpa and 10.09 Mpa, respectively. For both SB and PB, the blot dry group and one-second dry group revealed significantly higher bond strengths than the overwet and desiccated groups (P<0.05). Conclusions In order to achieve the highest bond strength to dentin, keeping the dentin surface in an appropriately moist condition is critical for the one-bottle dentin adhesive systems with ethanol/water or acetone solvent.

  18. Flexible dynamic operation of solar-integrated power plant with solvent based post-combustion carbon capture (PCC) process

    International Nuclear Information System (INIS)

    Highlights: • Flexible operation of power and PCC plant may significantly increase operational revenue. • Higher optimal carbon capture rates observed with solar thermal energy input. • Solar thermal repowering of the power plant provides highest net revenue. • Constant optimal capture rate observed for one of the flexible operation cases. • Up to 42% higher revenue generation observed between two cases with solar input. - Abstract: This paper examines flexible operation of solvent-based post-combustion carbon capture (PCC) for the reduction of power plant carbon emissions while minimizing revenue loss due to the reduced power plant electricity output. The study is conducted using a model superstructure enveloping three plants; a power plant, a PCC plant and a solar thermal field where the power plant and PCC plant are operated flexibly under the influence of hourly electricity market and weather conditions. Reduced (surrogate) models for the reboiler duty and auxiliary power requirement for the carbon capture plant are generated and applied to simulate and compare four cases, (A) power plant with PCC, (B) power plant with solar assisted PCC, (C) power plant with PCC and solar repowering – variable net electricity output and (D) power plant with PCC and solar repowering – fixed net electricity output. Such analyses are conducted under dynamic conditions including power plant part-load operation while varying the capture rate to optimize the revenue of the power plant. Each case was simulated with a lower carbon price of $25/tonne-CO2 and a higher price of $50/tonne-CO2. The comparison of cases B–D found that optimal revenue generation for case C can be up to 42% higher than that of solar-assisted PCC (case B). Case C is found to be the most profitable with the lowest carbon emissions intensity and is found to exhibit a constant capture rate for both carbon prices. The optimal revenue for case D is slightly lower than case C for the lower carbon

  19. Standard Practice for Preparing Aircraft Cleaning Compounds, Liquid-Type, Temperature-Sensitive, or Solvent-Based, for Storage Stability Testing

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2009-01-01

    1.1 This practice covers the determination of the stability in storage of liquid enzyme-based, terpene-based, and solvent-based chemical cleaning compounds used to clean the exterior surfaces of aircraft. 1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  20. Mdea Based Solvents Used At the Lacq Processing Plant Utilisation de solvants à base de MDEA à l'usine de Lacq

    Directory of Open Access Journals (Sweden)

    Elgue J.

    2006-11-01

    Full Text Available The use of MDEA-based solvents has allowed the processing scheme of the sour natural gases treated at the Lacq plant to be modified, leading to substantial savings in operating costs. Compared to the well known SNPA-DEA process, the new MDEA-based solvents meet the same performance requirements as regards H2S and CO2 removal, but are far more economic in terms of energy consumption. MDEA is used to selectively remove H2S from the gas, while activated MDEA is used when total acid gas removal is necessary. The adequate activator has been selected from among a series of products, according to the actual plant specificity. Optimization of the process has included the selection of the proper contacting device : for this mass transfer enhanced by chemical first order reaction, structured packings have proven to be more efficient than trays. L'utilisation de solvants à base de MDEA a permis de modifier le schéma de désulfuration du gaz de Lacq et de réaliser ainsi de substantielles économies de traitement. Les procédés à base des nouveaux solvants permettent d'atteindre les mêmes performances d'élimination de H2S et du CO2, avec une consommation d'énergie très inférieure à celle du désormais classique procédé SNPA-DEA. La MDEA est utilisée pour l'enlèvement sélectif de l'H2S, alors que la MDEA activée permet l'élimination complète des composés acides. L'activateur le mieux adapté aux conditions de fonctionnement spécifiques des unités de Lacq a été sélectionné parmi une série de produits. Dans le cadre de l'optimisation des unités, les internes du contacteur gaz/liquide ont été changés : les garnissages structurés ont confirmé leur efficacité supérieure à celle des plateaux à clapets pour ce transfert de matière avec réaction chimique.

  1. Performance evaluation of titanium dioxide based dye-sensitized solar cells under the influence of anodization steps, nanotube length and ionic liquid-free redox electrolyte solvents

    Science.gov (United States)

    Cheong, Y. L.; Beh, K. P.; Yam, F. K.; Hassan, Z.

    2016-06-01

    In this work, highly ordered titanium dioxide (TiO2) nanotube (NT) arrays were synthesized on titanium foil using electrochemical anodization method. The morphological aspects of the nanotubes based on different anodization duration and number of anodization steps (maximum two) have been investigated. The nanotube arrays subsequently used as photoanode in a dye-sensitized solar cell (DSSC) assembly. The studies on the effects of different solvents for triiodide/iodide redox electrolyte and NT length towards the performance of DSSC were conducted. It is known that electrolyte solvent can significantly affect the photovoltaic conversion efficiency. It is noteworthy that longer NT length tends to yield higher efficiency due to better dye adsorption. However, when the NTs exceeded certain length the efficiency decreases instead. Meanwhile, a comparison of DSSC performance based on number of anodization steps on titanium was performed. Highly ordered NT arrays could be obtained using two-steps anodization, which proved to have positive effects on the DSSC performance. The highest photovoltaic conversion efficiency in this work is 2.04%, achieved by two-step anodization. The corresponding average nanotubes length was ˜18 μm, with acetonitrile (ACN) as the redox electrolyte solvent.

  2. Negative corona discharge-ion mobility spectrometry as a detection system for low density extraction solvent-based dispersive liquid-liquid microextraction.

    Science.gov (United States)

    Ebrahimi, Amir; Jafari, Mohammad T

    2015-03-01

    This paper deals with a method based on negative corona discharge ionization ion mobility spectrometry (NCD-IMS) for the analysis of ethion (as an organophosphorus pesticide). The negative ions such as O2(-) and NO(x)(-) were eliminated from the background spectrum to increase the instrument sensitivity. The method was used to specify the sample extracted via dispersive liquid-liquid microextraction (DLLME) based on low density extraction solvent. The ion mobility spectrum of ethion in the negative mode and the reduced mobility value for its ion peak are firstly reported and compared with those of the positive mode. In order to combine the low density solvent DLLME directly with NCD-IMS, cyclohexane was selected as the extraction solvent, helping us to have a direct injection up to 20 µL solution, without any signal interference. The method was exhaustively validated in terms of sensitivity, enrichment factor, relative recovery, and repeatability. The linear dynamic range of 0.2-100.0 µg L(-1), detection limit of 0.075 µg L(-1), and the relative standard deviation (RSD) of about 5% were obtained for the analysis of ethion through this method. The average recoveries were calculated about 68% and 92% for the grape juice and underground water, respectively. Finally, some real samples were analyzed and the feasibility of the proposed method was successfully verified by the efficient extraction of the analyte using DLLME before the analysis by NCD-IMS. PMID:25618728

  3. Medium-based optimization of an organic solvent-tolerant extracellular lipase from the isolated halophilic Alkalibacillus salilacus.

    Science.gov (United States)

    Samaei-Nouroozi, Amene; Rezaei, Shahla; Khoshnevis, Nika; Doosti, Mahmoud; Hajihoseini, Reza; Khoshayand, Mohammad Reza; Faramarzi, Mohammad Ali

    2015-09-01

    A haloalkaliphilic solvent-tolerant lipase was produced from Alkalibacillus salilacus within 48 h of growth in liquid medium. An overall 4.9-fold enhanced production was achieved over unoptimized media after medium optimization by statistical approaches. Plackett-Burman screening suggested lipase production maximally influenced by olive oil, KH2PO4, NaCl, and glucose; and response surface methodology predicted the appropriate levels of each parameter. Produced lipase was highly active and stable over broad ranges of temperature (15-65 °C), pH (4.0-11.0), and NaCl concentration (0-30 %) showing excellent thermostable, pH-stable, and halophilic properties. The enzyme was optimally active at pH 8.0 and 40 °C. Majority of cations, except some like Co(2+) and Al(3+) were positive signals for lipase activity. In addition, the presence of chemical agents and organic solvents with different log P ow was well tolerated by the enzyme. Finally, efficacy of lipase-mediated esterification of various alcohols with oleic acid in organic solvents was studied. PMID:26198037

  4. Regioselective enzymatic undecylenoylation of 8-chloroadenosine and its analogs with biomass-based 2-methyltetrahydrofuran as solvent.

    Science.gov (United States)

    Gao, Wen-Li; Liu, Huan; Li, Ning; Zong, Min-Hua

    2012-08-01

    2-Methyltetrahydrofuran (MeTHF), a biomass-derived compound, is a promising medium for biocatalysis and organometallic reactions. The regioselective acylation of 8-chloroadenosine (8-Cl-Ado) and its analogs was carried out in MeTHF with immobilized Penicillium expansum lipase. The lipase displayed more than twofold higher catalytic activity and much better thermostability in MeTHF than in other organic solvents and co-solvent systems. The optimum reaction medium, enzyme dosage, molar ratio of viny ester to nucleoside and reaction temperature for the enzymatic acylation of 8-Cl-Ado were MeTHF, 25 U/mL, 7.5 and 35 °C, respectively, under which the desirable 5'-O-undecylenoyl-8-Cl-Ado was obtained with a yield of 95% and a regioselectivity of >99% in 3 h. In addition, the lipase catalyzed regioselective undecylenoylation of other purine nucleosides, producing 5'-undecylenic acid esters with moderate to high yields (63-94%) and excellent 5'-regioselectivities (94->99%). Use of biomass-derived solvents might open up novel opportunities for sustainable and greener biocatalytic processes. PMID:22705510

  5. Enzymatic Synthesis of Glucose-Based Fatty Acid Esters in Bisolvent Systems Containing Ionic Liquids or Deep Eutectic Solvents

    Directory of Open Access Journals (Sweden)

    Kai-Hua Zhao

    2016-09-01

    Full Text Available Sugar fatty acid esters (SFAEs are biocompatible nonionic surfactants with broad applications in food, cosmetic, and pharmaceutical industries. They can be synthesized enzymatically with many advantages over their chemical synthesis. In this study, SFAE synthesis was investigated by using two reactions: (1 transesterification of glucose with fatty acid vinyl esters and (2 esterification of methyl glucoside with fatty acids, catalyzed by Lipozyme TLIM and Novozym 435 respectively. Fourteen ionic liquids (ILs and 14 deep eutectic solvents (DESs were screened as solvents, and the bisolvent system composed of 1-hexyl-3-methylimidazolium trifluoromethylsulfonate ([HMIm][TfO] and 2-methyl-2-butanol (2M2B was the best for both reactions, yielding optimal productivities (769.6 and 397.5 µmol/h/g, respectively which are superior to those reported in the literature. Impacts of different reaction conditions were studied for both reactions. Response surface methodology (RSM was employed to optimize the transesterification reaction. Results also demonstrated that as co-substrate, methyl glucoside yielded higher conversions than glucose, and that conversions increased with an increase in the chain length of the fatty acid moieties. DESs were poor solvents for the above reactions presumably due to their high viscosity and high polarity.

  6. Grid-based backbone correction to the ff12SB protein force field for implicit-solvent simulations.

    Science.gov (United States)

    Perez, Alberto; MacCallum, Justin L; Brini, Emiliano; Simmerling, Carlos; Dill, Ken A

    2015-10-13

    Force fields, such as Amber's ff12SB, can be fairly accurate models of the physical forces in proteins and other biomolecules. When coupled with accurate solvation models, force fields are able to bring insight into the conformational preferences, transitions, pathways, and free energies for these biomolecules. When computational speed/cost matters, implicit solvent is often used but at the cost of accuracy. We present an empirical grid-like correction term, in the spirit of cMAPs, to the combination of the ff12SB protein force field and the GBneck2 implicit-solvent model. Ff12SB-cMAP is parametrized on experimental helicity data. We provide validation on a set of peptides and proteins. Ff12SB-cMAP successfully improves the secondary structure biases observed in ff12SB + Gbneck2. Ff12SB-cMAP can be downloaded ( https://github.com/laufercenter/Amap.git ) and used within the Amber package. It can improve the agreement of force fields + implicit solvent with experiments. PMID:26574266

  7. Low pressure methane solubility in lithium-ion batteries based solvents and electrolytes as a function of temperature. Measurement and prediction

    International Nuclear Information System (INIS)

    Highlights: • CH4 solubility is measured in pure alkylcarbonates and their binary mixtures. • The CH4 solubility increases in the following order: EC < PC < DMC < EMC < DEC. • The dissolution of the CH4 in all systems was compared to the CO2 solubility. • CH4 solubility was predicted using COSMOthermX and compared to measurements. - Abstract: The methane solubility in five pure electrolyte solvents and one binary solvent mixture for lithium ion batteries – such as ethylene carbonate (EC), propylene carbonate (PC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), diethyl carbonate (DEC) and the (50:50 wt%) mixture of EC:DMC was studied experimentally at pressures close to atmospheric and as a function of temperature between (280 and 343) K by using an isochoric saturation technique. The effect of the selected anions of a lithium salt LiX (X = hexafluorophosphate, PF6-; tris(pentafluoroethane)trifluorurophosphate, FAP−; bis(trifluoromethylsulfonyl)imide, TFSI−) on the methane solubility in electrolytes for lithium ion batteries was then investigated using a model electrolyte based on the binary mixture of EC:DMC (50:50 wt%) + 1 mol · dm−3 of lithium salt in the same temperature and pressure ranges. Based on experimental solubility data, the Henry’s law constant of the methane in these solutions were then deduced and compared together and with those predicted by using COSMO-RS methodology within COSMOthermX software. From this study, it appears that the methane solubility in each pure solvent decreases with the temperature and increases in the following order: EC < PC < EC:EMC (50:50 wt%) < DMC < EMC < DEC, showing that this increases with the van der Walls force in solution. Additionally, in all investigated EC:DMC (50:50 wt%) + 1 mol · dm−3 of lithium salt electrolytes, the methane solubility decreases also with the temperature and the methane solubility is higher in the electrolyte containing the LiFAP salt, followed by that based on

  8. A homochiral vanadium-salen based cadmium bpdc MOF with permanent porosity as an asymmetric catalyst in solvent-free cyanosilylation.

    Science.gov (United States)

    Bhunia, Asamanjoy; Dey, Subarna; Moreno, José María; Diaz, Urbano; Concepcion, Patricia; Van Hecke, Kristof; Janiak, Christoph; Van Der Voort, Pascal

    2016-01-25

    A homochiral vanadium-salen based MOF with the pcu topology is constructed via in situ synthesis under solvothermal conditions. The synthesized MOF exhibits BET surface areas of 574 m(2) g(-1), showing the highest H2 adsorption capacity (1.05 wt% at 77 K, 1 bar) and the highest CO2 uptake (51 cm(3) g(-1) at 273 K, 1 bar) for currently known salen-based MOFs. This framework shows excellent performance as an asymmetric catalyst in solvent-free cyanosilylation. PMID:26621199

  9. Improving the Performances of Random Copolymer Based Organic Solar Cells by Adjusting the Film Features of Active Layers Using Mixed Solvents

    Directory of Open Access Journals (Sweden)

    Xiangwei Zhu

    2015-12-01

    Full Text Available A novel random copolymer based on donor–acceptor type polymers containing benzodithiophene and dithienosilole as donors and benzothiazole and diketopyrrolopyrrole as acceptors was designed and synthesized by Stille copolymerization, and their optical, electrochemical, charge transport, and photovoltaic properties were investigated. This copolymer with high molecular weight exhibited broad and strong absorption covering the spectra range from 500 to 800 nm with absorption maxima at around 750 nm, which would be very conducive to obtaining large short-circuits current densities. Unlike the general approach using single solvent to prepare the active layer film, mixed solvents were introduced to change the film feature and improve the morphology of the active layer, which lead to a significant improvement of the power conversion efficiency. These results indicate that constructing random copolymer with multiple donor and acceptor monomers and choosing proper mixed solvents to change the characteristics of the film is a very promising way for manufacturing organic solar cells with large current density and high power conversion efficiency.

  10. The effect of macromolecular crowding on the electrostatic component of barnase-barstar binding: a computational, implicit solvent-based study.

    Directory of Open Access Journals (Sweden)

    Helena W Qi

    Full Text Available Macromolecular crowding within the cell can impact both protein folding and binding. Earlier models of cellular crowding focused on the excluded volume, entropic effect of crowding agents, which generally favors compact protein states. Recently, other effects of crowding have been explored, including enthalpically-related crowder-protein interactions and changes in solvation properties. In this work, we explore the effects of macromolecular crowding on the electrostatic desolvation and solvent-screened interaction components of protein-protein binding. Our simple model enables us to focus exclusively on the electrostatic effects of water depletion on protein binding due to crowding, providing us with the ability to systematically analyze and quantify these potentially intuitive effects. We use the barnase-barstar complex as a model system and randomly placed, uncharged spheres within implicit solvent to model crowding in an aqueous environment. On average, we find that the desolvation free energy penalties incurred by partners upon binding are lowered in a crowded environment and solvent-screened interactions are amplified. At a constant crowder density (fraction of total available volume occupied by crowders, this effect generally increases as the radius of model crowders decreases, but the strength and nature of this trend can depend on the water probe radius used to generate the molecular surface in the continuum model. In general, there is huge variation in desolvation penalties as a function of the random crowder positions. Results with explicit model crowders can be qualitatively similar to those using a lowered "effective" solvent dielectric to account for crowding, although the "best" effective dielectric constant will likely depend on multiple system properties. Taken together, this work systematically demonstrates, quantifies, and analyzes qualitative intuition-based insights into the effects of water depletion due to crowding on the

  11. Solvent resistant nanofiltration membranes

    OpenAIRE

    Dutczak, Szymon Maria

    2011-01-01

    This thesis describes preparation and characterization of membranes for organic solvent filtration (OSF). The main aim was developing membranes for solvent resistant nanofiltration (SRNF) with molecular weight cut-off below 500 g mol-1.

  12. Organic Solvent Tropical Report

    International Nuclear Information System (INIS)

    This report provides the basis for closing the organic solvent safety issue. Sufficient information is presented to conclude that risk posed by an unmitigated organic solvent fire is within risk evaluation guidelines

  13. Economic analysis of thermal solvent processes

    International Nuclear Information System (INIS)

    Vapour extraction (VAPEX) uses horizontal well pairs and a gaseous solvent to mobilize the oil. Hybrid solvent processes inject a light hydrocarbon solvent in addition to sufficient amounts of steam to vaporize the solvent. This paper reviewed various laboratory model experiments that evaluated VAPEX and solvent-based processes for the recovery of heavy oil or bitumen. The project compared a VAPEX process, a thermal solvent reflux process and a hybrid-solvent SAGD process using scaled laboratory models. Several experimental models were used. The first high-pressure thermal solvent experiment was conducted with a laboratory model designed to scale a 20 m thick Burnt Lake reservoir. Propane was used as the solvent. The second sequence of experiments scaled a range of processes from VAPEX to hybrid solvents for an Athabasca bitumen reservoir using a sealed can type of model confined by a gaseous overburden with propane as the solvent. The third experiment was a hybrid solvent experiment in which propane and steam were injected simultaneously into the injector well. The final experiment was a propane-steam hybrid experiment at a higher steam injection rate. The aim of the study was to evaluate the processes, build a database of experimental performance and to determine whether any single process had a significant economic advantage. It was concluded that the lowest cost process for Athabasca bitumen was the thermal solvent hybrid process followed by low pressure SAGD. The thermal solvent experiment using hot propane injection recovered heavy oil at costs competitive to SAGD. Many of the experiments suggested a process life longer than 15 years, as the high viscosity of Athabasca bitumen and the resulting low diffusivity resulted in a slower oil recovery process. 5 refs., 3 tabs., 16 figs

  14. Solvent-Free Selective Condensations Based on the Formation of the Olefinic (C=C Bond Catalyzed by Organocatalyst

    Directory of Open Access Journals (Sweden)

    Heyuan Song

    2016-07-01

    Full Text Available Pyrrolidine and its derivatives were used to catalyze aldol and Knoevenagel condensations for the formation of the olefinic (C=C bond under solvent-free conditions. The 3-pyrrolidinamine showed high activity and afforded excellent yields of α,β-unsaturated compounds. The aldol condensation of aromatic/heterocyclic aldehydes with ketones affords enones in high conversion (99.5% and selectivity (92.7%. Good to excellent yields of α,β-unsaturated compounds were obtained in the Knoevenagel condensation of aldehydes with methylene-activated substrates.

  15. Some regularities in formation and solvent extraction of complexes in metal-salicylic acid or its derivative- organic base systems

    International Nuclear Information System (INIS)

    The influence of concentrations of the reagents, pH and solvent on the conditions for the formation and extraction of Sc, Ti, Zr, Hf, Th complexes has been examined in salicylic acid (H2Sal)-heterocyclic amine systems. The extraction chemism and factors, which affect the reactions between the metal ions and the ligands, are discussed. It has been shown that Zr, Hf, Ti form species of ion associate type, Sc and Th form different-ligand complexes under conditions for interphase equilibrium in a Me-H2Sal-heterocyclic amine system

  16. Solvent recycle/recovery

    Energy Technology Data Exchange (ETDEWEB)

    Paffhausen, M.W.; Smith, D.L.; Ugaki, S.N.

    1990-09-01

    This report describes Phase I of the Solvent Recycle/Recovery Task of the DOE Chlorinated Solvent Substitution Program for the US Air Force by the Idaho National Engineering Laboratory, EG G Idaho, Inc., through the US Department of Energy, Idaho Operations Office. The purpose of the task is to identify and test recovery and recycling technologies for proposed substitution solvents identified by the Biodegradable Solvent Substitution Program and the Alternative Solvents/Technologies for Paint Stripping Program with the overall objective of minimizing hazardous wastes. A literature search to identify recycle/recovery technologies and initial distillation studies has been conducted. 4 refs.

  17. Thermally activated solvent bonding of polymers

    OpenAIRE

    Ng, S H; Tjeung, R. T.; Z. F. Wang; Lu, A. C. W.; Rodriguez, I.; de Rooij, Nicolaas F.

    2010-01-01

    We present a thermally activated solvent bonding technique for the formation of embedded microstructures in polymer. It is based on the temperature dependent solubility of polymer in a liquid that is not a solvent at room temperature. With thermal activation, the liquid is transformed into a solvent of the polymer, creating a bonding capability through segmental or chain interdiffusion at the bonding interface. The technique has advantages over the more commonly used thermal bonding due to it...

  18. Synthesis of (E-2-Styrylchromones and Flavones by Base-Catalyzed Cyclodehydration of the Appropriate β-Diketones Using Water as Solvent

    Directory of Open Access Journals (Sweden)

    Joana Pinto

    2015-06-01

    Full Text Available A low cost, safe, clean and environmentally benign base-catalyzed cyclodehydration of appropriate β-diketones affording (E-2-styrylchromones and flavones in good yields is disclosed. Water was used as solvent and the reactions were heated using classical and microwave heating methods, under open and closed vessel conditions. β-Diketones having electron-donating and withdrawing substituents were used to evaluate the reaction scope. The reaction products were isolated in high purity by simple filtration and recrystallization from ethanol, when using 800 mg of the starting diketone under classical reflux heating conditions.

  19. EFFECTS OF SOLVENT, BASE, AND TEMPERATURE IN THE OPTIMISATION OF A NEW CATALYTIC SYSTEM FOR SONOGASHIRA CROSS-COUPLING USING NCP PINCER PALLADACYCLE

    Directory of Open Access Journals (Sweden)

    Diego S. Rosa

    2015-05-01

    Full Text Available The optimisation of a new catalyst system using NCP pincer palladacycle 1 was investigated using the experimental design technique. NCP pincer palladacycle 1 was previously investigated in Suzuki-Miyaura and Heck-Mizoroki cross-couplings and found to be a highly efficient catalyst precursor. In this study, the effects of the type of base (K3PO4 or DABCO, solvent (DMF or dioxane and reaction temperature (130 or 150 ºC in the second step on the reactional yield in Sonogashira cross-coupling were assessed using the two-factor design. The results showed that temperature is statistically significant in relation to the reaction yield.

  20. PSE For Solvent Applications: A Generic Computer-aided Solvent Selection and Design Framework

    DEFF Research Database (Denmark)

    Mitrofanov, Igor; Sin, Gürkan; Gani, Rafiqul

    industry (API solubility), solvents i! ! n formulations and as cleaning agents. The template is expected to guide the average user through the essential and desirable steps in solvent selection and design. The expert may also use the general interface and create their own template for the types of solvent......Solvents are widely used across a number of industries in many applications such as separation agents, reaction mediums, cleaning agents and product carriers. Selection of optimal solvents in these applications is mostly based on previous experiences and experimental trial and error. A process...... related problems they usually solve. The solvents database currently contains information about more than 1000 organic solvents and their properties -including environmental and transportation - and about 1000 ionic liquids useful for extraction-based separation processes. Property models library include...

  1. Effect of solvent and additives on the open-circuit voltage of ZnO-based dye-sensitized solar cells: a combined theoretical and experimental study.

    Science.gov (United States)

    Le Bahers, Tangui; Labat, Frédéric; Pauporté, Thierry; Ciofini, Ilaria

    2010-11-28

    We have investigated the role of electrolyte composition, in terms of solvent and additive, on the open-circuit voltage (V(oc)) of ZnO-based dye-sensitized solar cells (DSSCs) using a combined experimental and theoretical approach. Calculations based on density functional theory (DFT) have been performed in order to describe the geometries and adsorption energies of various adsorbed solvents (nitromethane, acetonitrile and dimethylformamide) and p-tert-butylpyridine (TBP) (modeled by methylpyridine) on the ZnO (100) surface using a periodic approach. The densities of states (DOS) have been calculated and the energy position of the conduction band edge (CBE) has been evaluated for the different molecules adsorbed. The effect of the electrolyte composition on the standard redox potential of the iodide/triiodide redox couple has been experimentally determined. These two data values (CBE and standard redox potential) allowed us to determine the dependence of V(oc) on the electrolyte composition. The variations determined using this method were in good agreement with the measured V(oc) for cells made of electrodeposited ZnO films sensitized using D149 (indoline) dye. As in the case of TiO(2)-based cells, a correlation of V(oc) with the donor number of the adsorbed species was found. The present study clearly points out that both the CBE energy and the redox potential variation are important for explaining the experimentally observed changes in the V(oc) of DSSCs. PMID:20949189

  2. Emulsion-Based RIR-MAPLE Deposition of Conjugated Polymers: Primary Solvent Effect and Its Implications on Organic Solar Cell Performance.

    Science.gov (United States)

    Ge, Wangyao; Li, Nan K; McCormick, Ryan D; Lichtenberg, Eli; Yingling, Yaroslava G; Stiff-Roberts, Adrienne D

    2016-08-01

    Emulsion-based, resonant infrared matrix-assisted pulsed laser evaporation (RIR-MAPLE) has been demonstrated as an alternative technique to deposit conjugated polymer films for photovoltaic applications; yet, a fundamental understanding of how the emulsion target characteristics translate into film properties and solar cell performance is unclear. Such understanding is crucial to enable the rational improvement of organic solar cell (OSC) efficiency and to realize the expected advantages of emulsion-based RIR-MAPLE for OSC fabrication. In this paper, the effect of the primary solvent used in the emulsion target is studied, both experimentally and theoretically, and it is found to determine the conjugated polymer cluster size in the emulsion as well as surface roughness and internal morphology of resulting polymer films. By using a primary solvent with low solubility-in-water and low vapor pressure, the surface roughness of deposited P3HT and PCPDTBT polymer films was reduced to 10 nm, and the efficiency of P3HT:PC61BM OSCs was increased to 3.2% (∼100 times higher compared to the first MAPLE OSC demonstration [ Caricato , A. P. ; Appl. Phys. Lett. 2012 , 100 , 073306 ]). This work unveils the mechanism of polymer film formation using emulsion-based RIR-MAPLE and provides insight and direction to determine the best ways to take advantage of the emulsion target approach to control film properties for different applications. PMID:27414167

  3. Membrane-Based Osmotic Heat Engine with Organic Solvent for Enhanced Power Generation from Low-Grade Heat

    Energy Technology Data Exchange (ETDEWEB)

    Shaulsky, E; Boo, C; Lin, SH; Elimelech, M

    2015-05-05

    We present a hybrid osmotic heat engine (OHE) system that uses draw solutions with an organic solvent for enhanced thermal separation efficiency. The hybrid OHE system produces sustainable energy by combining pressure-retarded osmosis (PRO) as a power generation stage and membrane distillation (MD) utilizing low-grade heat as a separation stage. While previous OHE systems employed aqueous electrolyte draw solutions, using methanol as a solvent is advantageous because methanol is highly volatile and has a lower heat capacity and enthalpy of vaporization than water. Hence, the thermal separation efficiency of a draw solution with methanol would be higher than that of an aqueous draw solution. In this study, we evaluated the performance of LiCl-methanol as a potential draw solution for a PRO-MD hybrid OHE system. The membrane transport properties as well as performance with LiCl methanol draw solution were evaluated using thin-film composite (TFC) PRO membranes and compared to the results obtained with a LiCl water draw solution. Experimental PRO methanol flux and maximum projected power density of 47.1 L m(-2) h(-1) and 72.1 W m(-2), respectively, were achieved with a 3 M LiCl-methanol draw solution. The overall efficiency of the hybrid OHE system was modeled by coupling the mass and energy flows between the thermal separation (MD) and power generation (PRO) stages under conditions with and without heat recovery. The modeling results demonstrate higher ORE energy efficiency with the LiCl methanol draw solution compared to that with the LiCl water draw solution under practical operating conditions (i.e., heat recovery <90%). We discuss the implications of the results for converting low-grade heat to power.

  4. Water based on a molecular model behaves like a hard-sphere solvent for a nonpolar solute when the reference interaction site model and related theories are employed

    Science.gov (United States)

    Hayashi, Tomohiko; Oshima, Hiraku; Harano, Yuichi; Kinoshita, Masahiro

    2016-09-01

    For neutral hard-sphere solutes, we compare the reduced density profile of water around a solute g(r), solvation free energy μ, energy U, and entropy S under the isochoric condition predicted by the two theories: dielectrically consistent reference interaction site model (DRISM) and angle-dependent integral equation (ADIE) theories. A molecular model for water pertinent to each theory is adopted. The hypernetted-chain (HNC) closure is employed in the ADIE theory, and the HNC and Kovalenko–Hirata (K–H) closures are tested in the DRISM theory. We also calculate g(r), U, S, and μ of the same solute in a hard-sphere solvent whose molecular diameter and number density are set at those of water, in which case the radial-symmetric integral equation (RSIE) theory is employed. The dependences of μ, U, and S on the excluded volume and solvent-accessible surface area are analyzed using the morphometric approach (MA). The results from the ADIE theory are in by far better agreement with those from computer simulations available for g(r), U, and μ. For the DRISM theory, g(r) in the vicinity of the solute is quite high and becomes progressively higher as the solute diameter d U increases. By contrast, for the ADIE theory, it is much lower and becomes further lower as d U increases. Due to unphysically positive U and significantly larger |S|, μ from the DRISM theory becomes too high. It is interesting that μ, U, and S from the K–H closure are worse than those from the HNC closure. Overall, the results from the DRISM theory with a molecular model for water are quite similar to those from the RSIE theory with the hard-sphere solvent. Based on the results of the MA analysis, we comparatively discuss the different theoretical methods for cases where they are applied to studies on the solvation of a protein.

  5. Fluorescent derivatization combined with aqueous solvent-based dispersive liquid-liquid microextraction for determination of butyrobetaine, l-carnitine and acetyl-l-carnitine in human plasma.

    Science.gov (United States)

    Chen, Yi-Ching; Tsai, Chia-Ju; Feng, Chia-Hsien

    2016-09-16

    A novel aqueous solvent-based dispersive liquid-liquid microextraction (AS-DLLME) method was combined with narrow-bore liquid chromatography and fluorescence detection for the determination of hydrophilic compounds. A remover (non-polar solvent) and extractant (aqueous solution) were introduced into the derivatization system (acetonitrile) to obtain a water-in-oil emulsion state that increased the mass transfer of analytes. As a proof of concept, three quaternary ammonium substances, including butyrobetaine, l-carnitine and acetyl-l-carnitine, were also used as analytes and determined in pharmaceuticals, personal care products, food and human plasma. The analytes were derivatized with 4-bromomethylbiphenyl for fluorescence detection and improved retention in the column. The linear response was 10-2000nM for l-carnitine and acetyl-l-carnitine with a good determination coefficient (r(2)>0.998) in the standard solution. The detection limit for l-carnitine and acetyl-l-carnitine was 4.5 fmol. The method was also successfully applied to a 1μL sample of human plasma. In the linearity calculations for determining butyrobetaine, l-carnitine and acetyl-l-carnitine in human plasma, the determination coefficients ranged from 0.996 to 0.999. Linear regression exhibited good reproducibility and a relative standard deviation better than 7.50% for the slope and 9.06% for the intercept. To characterize highly hydrophilic compounds in various samples, the proposed method provides good sensitivity for a small sample volume with a low consumption of toxic solvents.

  6. Water based on a molecular model behaves like a hard-sphere solvent for a nonpolar solute when the reference interaction site model and related theories are employed.

    Science.gov (United States)

    Hayashi, Tomohiko; Oshima, Hiraku; Harano, Yuichi; Kinoshita, Masahiro

    2016-09-01

    For neutral hard-sphere solutes, we compare the reduced density profile of water around a solute g(r), solvation free energy μ, energy U, and entropy S under the isochoric condition predicted by the two theories: dielectrically consistent reference interaction site model (DRISM) and angle-dependent integral equation (ADIE) theories. A molecular model for water pertinent to each theory is adopted. The hypernetted-chain (HNC) closure is employed in the ADIE theory, and the HNC and Kovalenko-Hirata (K-H) closures are tested in the DRISM theory. We also calculate g(r), U, S, and μ of the same solute in a hard-sphere solvent whose molecular diameter and number density are set at those of water, in which case the radial-symmetric integral equation (RSIE) theory is employed. The dependences of μ, U, and S on the excluded volume and solvent-accessible surface area are analyzed using the morphometric approach (MA). The results from the ADIE theory are in by far better agreement with those from computer simulations available for g(r), U, and μ. For the DRISM theory, g(r) in the vicinity of the solute is quite high and becomes progressively higher as the solute diameter d U increases. By contrast, for the ADIE theory, it is much lower and becomes further lower as d U increases. Due to unphysically positive U and significantly larger |S|, μ from the DRISM theory becomes too high. It is interesting that μ, U, and S from the K-H closure are worse than those from the HNC closure. Overall, the results from the DRISM theory with a molecular model for water are quite similar to those from the RSIE theory with the hard-sphere solvent. Based on the results of the MA analysis, we comparatively discuss the different theoretical methods for cases where they are applied to studies on the solvation of a protein. PMID:27366886

  7. Fluorescent derivatization combined with aqueous solvent-based dispersive liquid-liquid microextraction for determination of butyrobetaine, l-carnitine and acetyl-l-carnitine in human plasma.

    Science.gov (United States)

    Chen, Yi-Ching; Tsai, Chia-Ju; Feng, Chia-Hsien

    2016-09-16

    A novel aqueous solvent-based dispersive liquid-liquid microextraction (AS-DLLME) method was combined with narrow-bore liquid chromatography and fluorescence detection for the determination of hydrophilic compounds. A remover (non-polar solvent) and extractant (aqueous solution) were introduced into the derivatization system (acetonitrile) to obtain a water-in-oil emulsion state that increased the mass transfer of analytes. As a proof of concept, three quaternary ammonium substances, including butyrobetaine, l-carnitine and acetyl-l-carnitine, were also used as analytes and determined in pharmaceuticals, personal care products, food and human plasma. The analytes were derivatized with 4-bromomethylbiphenyl for fluorescence detection and improved retention in the column. The linear response was 10-2000nM for l-carnitine and acetyl-l-carnitine with a good determination coefficient (r(2)>0.998) in the standard solution. The detection limit for l-carnitine and acetyl-l-carnitine was 4.5 fmol. The method was also successfully applied to a 1μL sample of human plasma. In the linearity calculations for determining butyrobetaine, l-carnitine and acetyl-l-carnitine in human plasma, the determination coefficients ranged from 0.996 to 0.999. Linear regression exhibited good reproducibility and a relative standard deviation better than 7.50% for the slope and 9.06% for the intercept. To characterize highly hydrophilic compounds in various samples, the proposed method provides good sensitivity for a small sample volume with a low consumption of toxic solvents. PMID:27562416

  8. Water based on a molecular model behaves like a hard-sphere solvent for a nonpolar solute when the reference interaction site model and related theories are employed

    Science.gov (United States)

    Hayashi, Tomohiko; Oshima, Hiraku; Harano, Yuichi; Kinoshita, Masahiro

    2016-09-01

    For neutral hard-sphere solutes, we compare the reduced density profile of water around a solute g(r), solvation free energy μ, energy U, and entropy S under the isochoric condition predicted by the two theories: dielectrically consistent reference interaction site model (DRISM) and angle-dependent integral equation (ADIE) theories. A molecular model for water pertinent to each theory is adopted. The hypernetted-chain (HNC) closure is employed in the ADIE theory, and the HNC and Kovalenko-Hirata (K-H) closures are tested in the DRISM theory. We also calculate g(r), U, S, and μ of the same solute in a hard-sphere solvent whose molecular diameter and number density are set at those of water, in which case the radial-symmetric integral equation (RSIE) theory is employed. The dependences of μ, U, and S on the excluded volume and solvent-accessible surface area are analyzed using the morphometric approach (MA). The results from the ADIE theory are in by far better agreement with those from computer simulations available for g(r), U, and μ. For the DRISM theory, g(r) in the vicinity of the solute is quite high and becomes progressively higher as the solute diameter d U increases. By contrast, for the ADIE theory, it is much lower and becomes further lower as d U increases. Due to unphysically positive U and significantly larger |S|, μ from the DRISM theory becomes too high. It is interesting that μ, U, and S from the K-H closure are worse than those from the HNC closure. Overall, the results from the DRISM theory with a molecular model for water are quite similar to those from the RSIE theory with the hard-sphere solvent. Based on the results of the MA analysis, we comparatively discuss the different theoretical methods for cases where they are applied to studies on the solvation of a protein.

  9. Molecular Thermodynamic Modeling of Mixed Solvent Solubility

    DEFF Research Database (Denmark)

    Ellegaard, Martin Dela; Abildskov, Jens; O’Connell, John P.

    2010-01-01

    A method based on statistical mechanical fluctuation solution theory for composition derivatives of activity coefficients is employed for estimating dilute solubilities of 11 solid pharmaceutical solutes in nearly 70 mixed aqueous and nonaqueous solvent systems. The solvent mixtures range from ne...

  10. Influence of Solvent-Solvent and Solute-Solvent Interaction Properties on Solvent-Mediated Potential

    Institute of Scientific and Technical Information of China (English)

    ZHOU Shi-Qi

    2005-01-01

    A recently proposed universal calculational recipe for solvent-mediated potential is applied to calculate excess potential of mean force between two large Lennard-Jones (LJ) or hard core attractive Yukawa particles immersed in small LJ solvent bath at supercritical state. Comparison between the present prediction with a hypernetted chain approximation adopted for solute-solute correlation at infinitely dilute limit and existing simulation data shows high accuracy for the region with large separation, and qualitative reliability for the solute particle contact region. The calculational simplicity of the present recipe allows for a detailed investigation on the effect of the solute-solvent and solvent-solvent interaction details on the excess potential of mean force. The resultant conclusion is that gathering of solvent particles near a solute particle leads to repulsive excess PMF, while depletion of solvent particles away from the solute particle leads to attractive excess PMF, and minor change of the solvent-solvent interaction range has large influence on the excess PMF.

  11. Determination of atenolol in human plasma using ionic-liquid-based ultrasound-assisted in situ solvent formation microextraction followed by high-performance liquid chromatography.

    Science.gov (United States)

    Zeeb, Mohsen; Farahani, Hadi; Papan, Mohammad Kazem

    2016-06-01

    An efficient analytical method called ionic-liquid-based ultrasound-assisted in situ solvent formation microextraction followed by high-performance liquid chromatography was developed for the determination of atenolol in human plasma. A hydrophobic ionic liquid (1-butyl-3-methylimidazolium hexafluorophosphate) was formed by the addition of a hydrophilic ionic liquid (1-butyl-3-methylimidazolium tetrafluoroborate) to a sample solution containing an ion-pairing agent during microextraction. The analyte was extracted into the ionic liquid phase while the microextraction solvent was dispersed throughout the sample by utilizing ultrasound. The sample was then centrifuged, and the extracting phase retracted into the microsyringe and injected to liquid chromatography. After optimization, the calibration curve showed linearity in the range of 2-750 ng/mL with the regression coefficient corresponding to 0.998. The limits of detection (S/N = 3) and quantification (S/N = 10) were 0.5 and 2 ng/mL, respectively. A reasonable relative recovery range of 90-96.7% and satisfactory intra-assay (4.8-5.1%, n = 6) and interassay (5.0-5.6%, n = 9) precision along with a substantial sample clean-up demonstrated good performance of the procedure. It was applied for the determination of atenolol in human plasma after oral administration and some pharmacokinetic data were obtained.

  12. Method for Predicting Solubilities of Solids in Mixed Solvents

    DEFF Research Database (Denmark)

    Ellegaard, Martin Dela; Abildskov, Jens; O'Connell, J. P.

    2009-01-01

    A method is presented for predicting solubilities of solid solutes in mixed solvents, based on excess Henry's law constants. The basis is statistical mechanical fluctuation solution theory for composition derivatives of solute/solvent infinite dilution activity coefficients. Suitable approximations...

  13. Alternative Green Solvents Project

    Science.gov (United States)

    Maloney, Phillip R.

    2012-01-01

    Necessary for safe and proper functioning of equipment. Mainly halogenated solvents. Tetrachloride, Trichloroethylene (TCE), CFC-113. No longer used due to regulatory/safety concerns. Precision Cleaning at KSC: Small % of total parts. Used for liquid oxygen (LOX) systems. Dual solvent process. Vertrel MCA (decafluoropentane (DFP) and trons-dichloroethylene) HFE-7100. DFP has long term environmental concerns. Project Goals: a) Identify potential replacements. b) 22 wet chemical processes. c) 3 alternative processes. d) Develop test procedures. e) Contamination and cleaning. f) Analysis. g) Use results to recommend alternative processes. Conclusions: a) No alternative matched Vertrel in this study. b) No clear second place solvent. c) Hydrocarbons- easy; Fluorinated greases- difficult. d) Fluorinated component may be needed in replacement solvent. e) Process may need to make up for shortcoming of the solvent. f) Plasma and SCC02 warrant further testing.

  14. Re-Refining of Waste Lubricating Oil by Solvent Extraction

    OpenAIRE

    Hassan Ali Durrani; Muhammed Ibrahim Panhwar; Rafique Akthar Kazi

    2011-01-01

    Re-refining of waste lubricating oil by solvent extraction is one of the potential techniques. The advantages of solvent extraction technique practically offers from environmental and economic points of view have received due attention. In this paper selection of composite solvent and technique to upgrade the used lubricant oil into base oil has been made. The composite solvent 2-propanol, 1-butanol and butanone have two alcohols that make a binary system reasonably effective. ...

  15. Method for Predicting Solubilities of Solids in Mixed Solvents

    OpenAIRE

    Ellegaard, Martin Dela; Abildskov, Jens; O'Connell, J P

    2009-01-01

    A method is presented for predicting solubilities of solid solutes in mixed solvents, based on excess Henry's law constants. The basis is statistical mechanical fluctuation solution theory for composition derivatives of solute/solvent infinite dilution activity coefficients. Suitable approximations are made for a single parameter characterizing solute/solvent interactions. Comparisons with available data show that the method is successful in describing a variety of observed mixed solvent solu...

  16. Temperature-based on-column solute focusing in capillary liquid chromatography reduces peak broadening from pre-column dispersion and volume overload when used alone or with solvent-based focusing.

    Science.gov (United States)

    Groskreutz, Stephen R; Horner, Anthony R; Weber, Stephen G

    2015-07-31

    On-column focusing is essential for satisfactory performance using capillary scale columns. On-column focusing results from generating transient conditions at the head of the column that lead to high solute retention. Solvent-based on-column focusing is a well-known approach to achieve this. Temperature-assisted on-column focusing (TASF) can also be effective. TASF improves focusing by cooling a short segment of the column inlet to a temperature that is lower than the column temperature during the injection and then rapidly heating the focusing segment to the match the column temperature. A troublesome feature of an earlier implementation of TASF was the need to leave the capillary column unpacked in that portion of the column inside the fitting connecting it to the injection valve. We have overcome that problem in this work by packing the head of the column with solid silica spheres. In addition, technical improvements to the TASF instrumentation include: selection of a more powerful thermo-electric cooler to create faster temperature changes and electronic control for easy incorporation into conventional capillary instruments. Used in conjunction with solvent-based focusing and with isocratic elution, volumes of paraben samples (esters of p-hydroxybenzoic acid) up to 4.5-times the column liquid volume can be injected without significant bandspreading due to volume overload. Interestingly, the shapes of the peaks from the lowest volume injections that we can make, 30nL, are improved when using TASF. TASF is very effective at reducing the detrimental effects of pre-column dispersion using isocratic elution. Finally, we show that TASF can be used to focus the neuropeptide galanin in a sample solvent with elution strength stronger than the mobile phase. Here, the stronger solvent is necessitated by the need to prevent peptide adsorption prior to and during analysis.

  17. Influence of solute-solvent coordination on the orientational relaxation of ion assemblies in polar solvents

    Science.gov (United States)

    Ji, Minbiao; Hartsock, Robert W.; Sung, Zheng; Gaffney, Kelly J.

    2012-01-01

    We have investigated the rotational dynamics of lithium thiocyanate (LiNCS) dissolved in various polar solvents with time and polarization resolved vibrational spectroscopy. LiNCS forms multiple distinct ionic structures in solution that can be distinguished with the CN stretch vibrational frequency of the different ionic assemblies. By varying the solvent and the LiNCS concentration, the number and type of ionic structures present in solution can be controlled. Control of the ionic structure provides control over the volume, shape, and dipole moment of the solute, critical parameters for hydrodynamic and dielectric continuum models of friction. The use of solutes with sizes comparable to or smaller than the solvent molecules also helps amplify the sensitivity of the measurement to the short-ranged solute-solvent interaction. The measured orientational relaxation dynamics show many clear and distinct deviations from simple hydrodynamic behavior. All ionic structures in all solvents exhibit multi-exponential relaxation dynamics that do not scale with the solute volume. For Lewis base solvents such as benzonitrile, dimethyl carbonate, and ethyl acetate, the observed dynamics strongly show the effect of solute-solvent complex formation. For the weak Lewis base solvent nitromethane, we see no evidence for solute-solvent complex formation, but still see strong deviation from the predictions of simple hydrodynamic theory.

  18. Development of a microfluidic-chip system for liquid-phase microextraction based on two immiscible organic solvents for the extraction and preconcentration of some hormonal drugs.

    Science.gov (United States)

    Asl, Yousef Abdossalami; Yamini, Yadollah; Seidi, Shahram

    2016-11-01

    In the present study, for the first time, an on-chip liquid phase microextraction (LPME) coupled with high performance liquid chromatography was introduced for the analysis of levonorgestrel (Levo), dydrogesterone (Dydo) and medroxyprogesterone (Medo) as the model analytes in biological samples. The chip-based LPME set-up was composed of two polymethyl methacrylate (PMMA) plates with microfabricated channels and a microporous membrane sandwiched between them to separate the sample solution and acceptor phase. These channels were used as a flow path for the sample solution and a thin compartment for the acceptor phase, respectively. In this system, two immiscible organic solvents were used as supported liquid membrane (SLM) and acceptor phase, respectively. During extraction, the model analytes in the sample solution were transported through the SLM (n-dodecane) into the acceptor organic solvent (methanol). The new set-up provided effective and reproducible extractions using low volumes of the sample solution. The effective parameters on the extraction efficiency of the model analytes were optimized using one variable at a time method. Under the optimized conditions, the new set-up provided good linearity in the range of 5.0-500µgL(-1) for the model analytes with the coefficients of determination (r(2)) higher than 0.9909. The relative standard deviations (RSDs%) and limits of detection (LODs) values were less than 6.5% (n=5) and 5.0µgL(-1), respectively. The preconcentration factors (PFs) were obtained using 1.0mL of the sample solution and 20.0µL of the acceptor solution higher than 19.9-fold. Finally, the proposed method was successfully applied for the extraction and determination of the model analytes in urine samples. PMID:27591655

  19. Comparative study of corn stover pretreated by dilute acid and cellulose solvent-based lignocellulose fractionation: Enzymatic hydrolysis, supramolecular structure, and substrate accessibility.

    Science.gov (United States)

    Zhu, Zhiguang; Sathitsuksanoh, Noppadon; Vinzant, Todd; Schell, Daniel J; McMillan, James D; Zhang, Y-H Percival

    2009-07-01

    Liberation of fermentable sugars from recalcitrant biomass is among the most costly steps for emerging cellulosic ethanol production. Here we compared two pretreatment methods (dilute acid, DA, and cellulose solvent and organic solvent lignocellulose fractionation, COSLIF) for corn stover. At a high cellulase loading [15 filter paper units (FPUs) or 12.3 mg cellulase per gram of glucan], glucan digestibilities of the corn stover pretreated by DA and COSLIF were 84% at hour 72 and 97% at hour 24, respectively. At a low cellulase loading (5 FPUs per gram of glucan), digestibility remained as high as 93% at hour 24 for the COSLIF-pretreated corn stover but reached only approximately 60% for the DA-pretreated biomass. Quantitative determinations of total substrate accessibility to cellulase (TSAC), cellulose accessibility to cellulase (CAC), and non-cellulose accessibility to cellulase (NCAC) based on adsorption of a non-hydrolytic recombinant protein TGC were measured for the first time. The COSLIF-pretreated corn stover had a CAC of 11.57 m(2)/g, nearly twice that of the DA-pretreated biomass (5.89 m(2)/g). These results, along with scanning electron microscopy images showing dramatic structural differences between the DA- and COSLIF-pretreated samples, suggest that COSLIF treatment disrupts microfibrillar structures within biomass while DA treatment mainly removes hemicellulose. Under the tested conditions COSLIF treatment breaks down lignocellulose structure more extensively than DA treatment, producing a more enzymatically reactive material with a higher CAC accompanied by faster hydrolysis rates and higher enzymatic digestibility.

  20. Solvent-mediated secondary building units (SBUs) diversification in a series of MnII-based metal-organic frameworks (MOFs)

    Science.gov (United States)

    Niu, Yan-Fei; Cui, Li-Ting; Han, Jie; Zhao, Xiao-Li

    2016-09-01

    The role of auxiliary solvents in the formation of MOFs has been investigated for a series of MnII-based framework systems. Reactions of 4,4‧,4″-nitrilotribenzoic acid (H3L) with MnII through varying auxiliary solvents of the medium resulted in the formation of diversified multinuclear MnII subunits in four new coordination polymers: [Mn3(L)(HCOO)3(DEF)3] (1), [Mn3(L)2(EtOH)2]·DMF (2), [Mn5(L)4(H2O)2]·2(H2NMe2)+·4DMF·2H2O (3), and [Mn3(L)2(py)4(H2O)]·H2O (4) (H3L=4,4‧,4‧-nitrilotribenzoic acid, DMF=dimethylformamide, DEF=N,N-diethylformamide, py=pyridine). These four compounds were fully characterized by single-crystal X-ray diffraction, showing interesting SBUs variations. For compound 1, it displays a (3,6)-connected kgd net with wheel [Mn6] cluster serving as SBU, whereas in 2, the sequence of Mn3(COO)9(EtOH)2 is repeated by inversion centers located between Mn1 and Mn3 to form an infinite Mn-carboxylate chain, which are further interlinked by L3- ligands to form a 3D architecture. In 3, the pentanuclear Mn5(CO2)12 clusters are interlinked to form a layer, which are further pillared by L3- to generate a 3D network. Compound 4 has a (3,6)-connected network in which the SBU is a linear trimeric Mn3(COO)6(py)4(H2O) cluster. In addition, the thermal stabilities, X-ray powder diffraction of all the compounds were studied, photoluminescence behaviors of compounds 1, 3 and 4 are discussed.

  1. Development of a microfluidic-chip system for liquid-phase microextraction based on two immiscible organic solvents for the extraction and preconcentration of some hormonal drugs.

    Science.gov (United States)

    Asl, Yousef Abdossalami; Yamini, Yadollah; Seidi, Shahram

    2016-11-01

    In the present study, for the first time, an on-chip liquid phase microextraction (LPME) coupled with high performance liquid chromatography was introduced for the analysis of levonorgestrel (Levo), dydrogesterone (Dydo) and medroxyprogesterone (Medo) as the model analytes in biological samples. The chip-based LPME set-up was composed of two polymethyl methacrylate (PMMA) plates with microfabricated channels and a microporous membrane sandwiched between them to separate the sample solution and acceptor phase. These channels were used as a flow path for the sample solution and a thin compartment for the acceptor phase, respectively. In this system, two immiscible organic solvents were used as supported liquid membrane (SLM) and acceptor phase, respectively. During extraction, the model analytes in the sample solution were transported through the SLM (n-dodecane) into the acceptor organic solvent (methanol). The new set-up provided effective and reproducible extractions using low volumes of the sample solution. The effective parameters on the extraction efficiency of the model analytes were optimized using one variable at a time method. Under the optimized conditions, the new set-up provided good linearity in the range of 5.0-500µgL(-1) for the model analytes with the coefficients of determination (r(2)) higher than 0.9909. The relative standard deviations (RSDs%) and limits of detection (LODs) values were less than 6.5% (n=5) and 5.0µgL(-1), respectively. The preconcentration factors (PFs) were obtained using 1.0mL of the sample solution and 20.0µL of the acceptor solution higher than 19.9-fold. Finally, the proposed method was successfully applied for the extraction and determination of the model analytes in urine samples.

  2. Emulsification liquid-liquid microextraction based on deep eutectic solvent: An extraction method for the determination of benzene, toluene, ethylbenzene and seven polycyclic aromatic hydrocarbons from water samples.

    Science.gov (United States)

    Khezeli, Tahere; Daneshfar, Ali; Sahraei, Reza

    2015-12-18

    In this study, for the first time, a simple, inexpensive and sensitive method named emulsification liquid-liquid microextraction based on deep eutectic solvent (ELLME-DES) was used for the extraction of benzene, toluene, ethylbenzene (BTE) and seven polycyclic aromatic hydrocarbons (PAHs) from water samples. In a typical experiment, 100μL of DES (as water-miscible extraction solvent) was added to 1.5mL of sample solution containing target analytes. A homogeneous solution was formed immediately. Injection of 100μL of THF (as emulsifier agent) into homogeneous solution provided a turbid state. After extraction, phase separation (aqueous phase/DES rich phase) was performed by centrifugation. DES rich phase was withdrawn by a micro-syringe and submitted to isocratic reverse-phase HPLC with UV detection. Under optimum conditions obtained by response surface methodology (RSM) and desirability function (DF), the calibration graphs were linear in the concentration range from 10 to 200μg/L for benzene, 10-400μg/L for toluene, 1-400μg/L for ethylbenzene, biphenyl, chrysene and fluorene, and 0.1-400μg/L for anthracene, benzo[a]pyrene, phenanthrene and pyrene. The coefficients of determination (r(2)) and limits of detection were 0.9924-0.9997 and 0.02-6.8μg/L, respectively. This procedure was successfully applied to the determination of target analytes in spiked water samples. The relative mean recoveries ranged from 93.1 to 103.3%. PMID:26614169

  3. Coumarin-decorated Schiff base hydrolysis as an efficient driving force for the fluorescence detection of water in organic solvents.

    Science.gov (United States)

    Kim, Won Young; Shi, Hu; Jung, Hyo Sung; Cho, Daeheum; Verwilst, Peter; Lee, Jin Yong; Kim, Jong Seung

    2016-07-01

    A coumarin based Schiff base was found to be an excellent indicator of moisture, via rapid in situ hydrolysis. A structure-relationship examination of a small library of Schiff bases revealed the critical importance of hydrogen bond acceptors in close proximity to the imine bond, and this observation was further supported by theoretical calculations as well as the solid state structure analysis. The most sensitive compound demonstrated a limit of detection and quantification of 0.18% and 0.54% v/v water in DMSO, respectively. PMID:27333263

  4. Supercritical solvent coal extraction

    Science.gov (United States)

    Compton, L. E. (Inventor)

    1984-01-01

    Yields of soluble organic extract are increased up to about 50% by the supercritical extraction of particulate coal at a temperature below the polymerization temperature for coal extract fragments (450 C.) and a pressure from 500 psig to 5,000 psig by the conjoint use of a solvent mixture containing a low volatility, high critical temperature coal dissolution catalyst such as phenanthrene and a high volatility, low critical temperature solvent such as toluene.

  5. SOLVENT EXTRACTION OF RUTHENIUM

    Science.gov (United States)

    Hyman, H.H.; Leader, G.R.

    1959-07-14

    The separation of rathenium from aqueous solutions by solvent extraction is described. According to the invention, a nitrite selected from the group consisting of alkali nitrite and alkaline earth nitrite in an equimolecular quantity with regard to the quantity of rathenium present is added to an aqueous solution containing ruthenium tetrantrate to form a ruthenium complex. Adding an organic solvent such as ethyl ether to the resulting mixture selectively extracts the rathenium complex.

  6. The orientation of solvent-dipoles at the surface of the pure solvent

    NARCIS (Netherlands)

    Nedermeijer-Denessen, H.J.M.; Ligny, C.L. de

    1975-01-01

    A method is described for the assessment of the preferential orientation of solvent-dipoles at the surface of the solvent from the surface potential χ and its temperature coefficient, dχ/dT. The method is based on the model of Levine et al. of the Stern inner region at the mercury-water interface in

  7. Effect of solvents on propylene epoxidation over TS-1 catalyst

    Institute of Scientific and Technical Information of China (English)

    Yulong WU; Qingshan LIU; Xueli SU; Zhentao MI

    2008-01-01

    Solvents have an important effect on the epoxidation of propylene catalyzed by TS-1. The experimental results show that, in different solvents, the catalytic activity of epoxidation is in the following order: methanol > 2-propanol > 2-butanol > acetoni-trile > acetone > tetrahydrofuran. Based on the reaction mechanism, the effects of solvents on the epoxidation were studied from eight aspects, which included the electronic effect, the steric effect, the polarity of solvent, the effect of solvent on sorption and diffusion of reactant, the oxidation of alcohol, the etherification of PO, the deactivation of TS-1 and the solubility of propylene in the solvents. The electronic effect, steric effect and the polarity of solvent were considered to be the main aspects. This work may provide theoretical guidance for choosing solvents for these kinds of reactions and also may serve as basis for further industrialization.

  8. Chemical reactions in solvents and melts

    CERN Document Server

    Charlot, G

    1969-01-01

    Chemical Reactions in Solvents and Melts discusses the use of organic and inorganic compounds as well as of melts as solvents. This book examines the applications in organic and inorganic chemistry as well as in electrochemistry. Organized into two parts encompassing 15 chapters, this book begins with an overview of the general properties and the different types of reactions, including acid-base reactions, complex formation reactions, and oxidation-reduction reactions. This text then describes the properties of inert and active solvents. Other chapters consider the proton transfer reactions in

  9. A solvent/non-solvent system for achieving solution-processed multilayer organic light-emitting devices

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Yue; Wu, Zhaoxin, E-mail: zhaoxinwu@mail.xjtu.edu.cn; He, Lin; Jiao, Bo; Hou, Xun

    2015-08-31

    We developed a solvent/non-solvent system to fabricate the multilayer organic light-emitting devices (OLEDs) based on poly(N-vinylcarbazole) (PVK) by solution-process. This solvent system consists of both the solvent and non-solvent of PVK, in which fluorescent small molecules could be fully dissolved and directly spin-coated on top of the PVK layer; it could effectively avoid the redissolution of PVK during the spin-coating process of small molecules emitting layer. In the further investigation of this system, we also demonstrated the three-component solvent system, and found out that the third component, a less volatile solvent of PVK, was crucial for preparing a smoother interface between PVK and emitting layer. Compared with OLEDs through the vacuum deposition, the devices fabricated by solution-process from the solvent/non-solvent system showed comparable efficiency, which indicate that the solvent/non-solvent system can be used as an alternative process to prepare the polymer and small molecule multilayer devices through all-solution-process. - Highlights: • We fabricate the multilayer OLEDs by solution-process using a novel system. • We develop a solvent/non-solvent system of polymer (PVK) to avoid redissolution. • Small molecules could be fully dissolved and directly spin-coated on PVK layer. • The devices fabricated by the system and vacuum deposition show comparable efficiency.

  10. A solvent/non-solvent system for achieving solution-processed multilayer organic light-emitting devices

    International Nuclear Information System (INIS)

    We developed a solvent/non-solvent system to fabricate the multilayer organic light-emitting devices (OLEDs) based on poly(N-vinylcarbazole) (PVK) by solution-process. This solvent system consists of both the solvent and non-solvent of PVK, in which fluorescent small molecules could be fully dissolved and directly spin-coated on top of the PVK layer; it could effectively avoid the redissolution of PVK during the spin-coating process of small molecules emitting layer. In the further investigation of this system, we also demonstrated the three-component solvent system, and found out that the third component, a less volatile solvent of PVK, was crucial for preparing a smoother interface between PVK and emitting layer. Compared with OLEDs through the vacuum deposition, the devices fabricated by solution-process from the solvent/non-solvent system showed comparable efficiency, which indicate that the solvent/non-solvent system can be used as an alternative process to prepare the polymer and small molecule multilayer devices through all-solution-process. - Highlights: • We fabricate the multilayer OLEDs by solution-process using a novel system. • We develop a solvent/non-solvent system of polymer (PVK) to avoid redissolution. • Small molecules could be fully dissolved and directly spin-coated on PVK layer. • The devices fabricated by the system and vacuum deposition show comparable efficiency

  11. Effect of different solvents on the performance of organic light-emitting device based on red-fluorescent ACY dye by spin coating method

    Science.gov (United States)

    Yu, Shuangjiang; Yu, Junsheng; Wang, Hong; Jiang, Yadong

    2010-10-01

    A small-molecular red-fluorescent dye of [7-diethylamino-3-(2-thienyl)chronmen-2-ylidene]-2,2-dicyanoviny-lamine (ACY) has been blended into blue-emitting poly(N-vinylcarbazole) (PVK) by using different solvents of chloroform and 1,2-dichloroethane. Photoluminescence characteristic of solvent effects were investigated mainly from the aspect of solvent polarity. To demonstrate the solvent effects in organic light emitting devices (OLEDs), devices with a structure of indium-tin-oxide (ITO)/PVK: ACY (x wt %)/tris(8-quinolinolato) aluminum (Alq3)/Mg: Ag were fabricated, in which the weight doping ratios are x = 0.3, 0.5 and 0.7. Using spin coating method, a blending system of PVK: ACY is dissolved in both chloroform and 1,2-dichloroethane with various doping concentrations. As a result, by choosing chloroform as solvent, a high electroluminescent (EL) performance device with a maximum luminance of 7698 cd/m2 at a driving voltage of 15.5 V was obtained, with a concentration proportion of PVK: ACY at 1000: 7. In the EL spectra of the OLEDs, red and green fluorescence of ACY and Alq3 were detected. It was found that by using 1,2-dichloroethane as a solvent, fluorescent quenching emerged with the enhancement of doping concentration. Energy transfer and Alq3 cations quencher theories were used to discuss different solvent effects on OLEDs.

  12. Cost-Benefit Analysis of Nanoparticle Albumin-Bound Paclitaxel versus Solvent-Based Paclitaxel for the Treatment of Metastatic Breast Cancer in the United States

    Science.gov (United States)

    Vichansavakul, Kittaya

    Breast cancer is the second leading cause of death among women in the US. Although early detection and treatment help to increase survival rates, some unfortunate patients develop metastatic breast cancer that has no cure. Palliative treatment is the main objective in this group of patients in order to prolong life and reduce toxicities from interventions. In the advancement of treatment for metastatic breast cancer, solvent-based paclitaxel has been widely used. However, solvent-based paclitaxel often causes adverse reactions. Therefore, researchers have developed a new chemotherapy based on nanotechnology. One of these drugs is the Nanoparticle albumin-bound Paclitaxel. This nanodrug aims to increase therapeutic index by reducing adverse reactions from solvents and to improve efficacy of conventional cytotoxic chemotherapy. Breast cancer is a disease with high epidemiological and economic burden. The treatment of metastatic breast cancer has not only high direct costs but also high indirect costs. Breast cancer affects mass populations, especially women younger than 50 years of age. It relates to high indirect costs due to lost productivity and premature death because the majority of these patients are in the workforce. Because of the high cost of breast cancer therapies and short survival rates, the question is raised whether the costs and benefits are worth paying or not. Due to the rising costs in healthcare and new financing policies that have been developed to address this issue, economic evaluation is an important aspect of the development and use of any new interventions. To guide policy makers on how to allocate limited healthcare resources in the most efficient and effective manner, many economic evaluation methods can be used to measure the costs, benefits, and impacts of healthcare innovations. Currently, economic evaluation and health outcomes studies have focused greatly on cost-effectiveness and cost-utility analysis. However, the previous studies

  13. Solvent-treated PEDOT:PSS on the improvement PTB7 based on polymer solar cells performance

    Science.gov (United States)

    Huang, Di; Xu, Zheng; Zhao, Suling; Li, Yang; Zhao, Ling; Jin, Shi Qi

    2015-10-01

    In this manuscript, the effect of the 2-propanol(IPA)-treated poly(3,4-ethylenedioxy-thiophene):poly(styrenesulfonate) (PEDOT:PSS) on the performance enhancement of polymer solar cells(PSCs) based on poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b‧]dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl

  14. A comparison of chilled DI water/ozone and CO{sub 2}-based supercritical fluids as replacements for photoresist-stripping solvents

    Energy Technology Data Exchange (ETDEWEB)

    Rubin, J.B.; Davenhall, L.B.; Barton, J.; Taylor, C.M.V. [Los Alamos National Lab., NM (United States). Chemical Science and Technology Div.; Tiefert, K. [Hewlett-Packard Co., Santa Clara, CA (United States)

    1998-12-31

    Part of the Hewlett Packard Components Group`s Product Stewardship program is the ongoing effort to investigate ways to eliminate or reduce as much as possible the use of chemical substances from manufacturing processes. Currently used techniques to remove hard-baked photoresists from semiconductor wafers require the use of inorganic chemicals or organic strippers and associated organic solvents. Environmental, health and safety, as well as cost considerations prompted the search for alternative, more environmentally-benign, and cost-effective solutions. Two promising, emerging technologies were selected for evaluation: the chilled DI water/ozone technique and supercritical fluids based on carbon dioxide (CO{sub 2}). Evaluating chilled DI water/ozone shows this process to be effective for positive photoresist removal, but may not be compatible with all metallization systems. Testing of a closed-loop CO{sub 2}-based supercritical CO{sub 2} Resist Remover, or SCORR, at Los Alamos, on behalf of Hewlett-packard, shows that this treatment process is effective in removing photoresists, and is fully compatible with commonly used metallization systems. In this paper, the authors present details on the testing programs conducted with both the chilled DI H{sub 2}O/ozone and SCORR treatment processes.

  15. Development and optimization of a naphthoic acid-based ionic liquid as a "non-organic solvent microextraction" for the determination of tetracycline antibiotics in milk and chicken eggs.

    Science.gov (United States)

    Gao, Jiajia; Wang, Hui; Qu, Jingang; Wang, Huili; Wang, Xuedong

    2017-01-15

    In traditional ionic liquids (ILs)-based microextraction, ILs are often used as extraction and dispersive solvents; however, their functional effects are not fully utilized. Herein, we developed a novel ionic liquid 1-butyl-3-methylimidazolium naphthoic acid salt ([C4MIM][NPA]) with strong acidity. It was used as a mixed dispersive solvent with conventional [C2MIM][BF4] in "functionalized ionic liquid-based non-organic solvent microextraction (FIL-NOSM)" for determination of tetracycline antibiotics (TCs) in milk and eggs. Utilization of [C4MIM][NPA] in FIL-NOSM method increased extraction recoveries (ERs) of TCs by more than 20% and eliminated the pH adjustment step because of its strong acidity. Under optimized conditions based on central composite design, the ERs of four TCs were 94.1-102.1%, and the limitsofdetection were 0.08-1.12μgkg(-1) in milk and egg samples. This proposed method provides high extraction efficiency, less pretreatment time and requires non-organic solvents for determination of trace TC concentrations in complex animal-based food matrices. PMID:27542460

  16. Purex process solvent: literature review

    International Nuclear Information System (INIS)

    This document summarizes the data on Purex process solvent presently published in a variety of sources. Extracts from these various sources are presented herein and contain the work done, the salient results obtained, and the original, unaltered conclusions of the author of each paper. Three major areas are addressed: solvent stability, solvent quality testing, and solvent treatment processes. 34 references, 44 tables

  17. Bioavailability of Organic Solvents in soils: Input into Biologically Based Dose-Response Models for Human Risk Assessments

    Energy Technology Data Exchange (ETDEWEB)

    Wester, Ronald C.

    1999-06-01

    The purpose of this study was to develop methods to expose rats and humans percutaneously and to use PBPK modeling to assess the percutaneous permeability of volatile compounds from aqueous or soil exposures. To estimate dermal absorption under realistic environmental exposure conditions, a patch system was developed that allowed for the volatilization of the compounds from the soil without contamination of inhaled or exhaled breath. The end product for this research will be a tested framework for the rapid screening of real and potential exposures while simultaneously developing physiologically based pharmacokinetic (PBPK) models to comprehensively evaluate and compare exposures to volatile chemicals from either contaminated soil or water.

  18. Single-stranded DNA detection by solvent-induced assemblies of a metallo-peptide-based complex

    Science.gov (United States)

    Das, Priyadip; Reches, Meital

    2016-05-01

    DNA detection is highly important for the sensitive sensing of different pathogenic bacteria and viruses. The major challenge is to create a sensor that can selectively detect very small concentrations of DNA without the need for amplification or complicated equipment. Different technologies such as optical, electrochemical and microgravimetric approaches can detect DNA fragments. Here we show, for the first time, the use of self-assembled nanostructures generated by a metallo-peptide as an optical sensing platform for DNA detection. The system can selectively detect single stranded DNA fragments by fluorescence measurements as it can discriminate even one base mismatch and can perform in the presence of other interfering proteins. This system may be useful in lab-on-a-chip applications.DNA detection is highly important for the sensitive sensing of different pathogenic bacteria and viruses. The major challenge is to create a sensor that can selectively detect very small concentrations of DNA without the need for amplification or complicated equipment. Different technologies such as optical, electrochemical and microgravimetric approaches can detect DNA fragments. Here we show, for the first time, the use of self-assembled nanostructures generated by a metallo-peptide as an optical sensing platform for DNA detection. The system can selectively detect single stranded DNA fragments by fluorescence measurements as it can discriminate even one base mismatch and can perform in the presence of other interfering proteins. This system may be useful in lab-on-a-chip applications. Electronic supplementary information (ESI) available: Peptide and receptor synthesis, characterization of the final and intermediate products, experimental details and additional figures including SEM, TEM, DLS, XRD, UV analysis and AFM topographic analysis. See DOI: 10.1039/c5nr07714a

  19. Single Stage Contactor Testing Of The Next Generation Solvent Blend

    Energy Technology Data Exchange (ETDEWEB)

    Herman, D. T.; Peters, T. B.; Duignan, M. R.; Williams, M. R.; Poirier, M. R.; Brass, E. A.; Garrison, A. G.; Ketusky, E. T.

    2014-01-06

    The Modular Caustic Side Solvent Extraction (CSSX) Unit (MCU) facility at the Savannah River Site (SRS) is actively pursuing the transition from the current BOBCalixC6 based solvent to the Next Generation Solvent (NGS)-MCU solvent to increase the cesium decontamination factor. To support this integration of NGS into the MCU facility the Savannah River National Laboratory (SRNL) performed testing of a blend of the NGS (MaxCalix based solvent) with the current solvent (BOBCalixC6 based solvent) for the removal of cesium (Cs) from the liquid salt waste stream. This testing utilized a blend of BOBCalixC6 based solvent and the NGS with the new extractant, MaxCalix, as well as a new suppressor, tris(3,7dimethyloctyl) guanidine. Single stage tests were conducted using the full size V-05 and V-10 liquid-to-liquid centrifugal contactors installed at SRNL. These tests were designed to determine the mass transfer and hydraulic characteristics with the NGS solvent blended with the projected heel of the BOBCalixC6 based solvent that will exist in MCU at time of transition. The test program evaluated the amount of organic carryover and the droplet size of the organic carryover phases using several analytical methods. The results indicate that hydraulically, the NGS solvent performed hydraulically similar to the current solvent which was expected. For the organic carryover 93% of the solvent is predicted to be recovered from the stripping operation and 96% from the extraction operation. As for the mass transfer, the NGS solvent significantly improved the cesium DF by at least an order of magnitude when extrapolating the One-stage results to actual Seven-stage extraction operation with a stage efficiency of 95%.

  20. Optical properties of a long dynamic range chemical UV dosimeter based on solvent cast polyvinyl chloride (PVC).

    Science.gov (United States)

    Amar, Abdurazaq; Parisi, Alfio V

    2013-11-01

    The dosimetric properties of the recently introduced UV dosimeter based on 16 μm PVC film have been fully characterised. Drying the thin film in air at 50 °C for at least 28 days was found to be necessary to minimise the temperature effects on the dosimeter response. This research has found that the dosimeter response, previously reported to be mainly to UVB, has no significant dependence on either exposure temperature or dose rate. The dosimeter has negligible dark reaction and responds to the UV radiation with high reproducibility. The dosimeter angular response was found to have a similar pattern as the cosine function but deviates considerably at angles larger than 70°. Dose response curves exhibit monotonically increasing shape and the dosimeter can measure more than 900 SED. This is about 3 weeks of continuous exposure during summer at subtropical sites. Exposures measured by the PVC dosimeter for some anatomical sites exposed to solar radiation for twelve consecutive days were comparable with those concurrently measured by a series of PPO dosimeters and were in line with earlier results reported in similar studies.

  1. Safe battery solvents

    Science.gov (United States)

    Harrup, Mason K.; Delmastro, Joseph R.; Stewart, Frederick F.; Luther, Thomas A.

    2007-10-23

    An ion transporting solvent maintains very low vapor pressure, contains flame retarding elements, and is nontoxic. The solvent in combination with common battery electrolyte salts can be used to replace the current carbonate electrolyte solution, creating a safer battery. It can also be used in combination with polymer gels or solid polymer electrolytes to produce polymer batteries with enhanced conductivity characteristics. The solvents may comprise a class of cyclic and acyclic low molecular weight phosphazenes compounds, comprising repeating phosphorus and nitrogen units forming a core backbone and ion-carrying pendent groups bound to the phosphorus. In preferred embodiments, the cyclic phosphazene comprises at least 3 phosphorus and nitrogen units, and the pendent groups are polyethers, polythioethers, polyether/polythioethers or any combination thereof, and/or other groups preferably comprising other atoms from Group 6B of the periodic table of elements.

  2. Congenital anomalies in newborns to women employed in jobs with frequent exposure to organic solvents - a register-based prospective study

    Directory of Open Access Journals (Sweden)

    Talykova Ljudmila V

    2011-10-01

    Full Text Available Abstract Background The foetal effects of occupational exposure to organic solvents in pregnancy are still unclear. Our aim was to study the risk of non-chromosomal congenital anomalies at birth in a well-defined population of singletons born to women employed as painters and spoolers in early pregnancy, compared to women in non-hazardous occupations. Method The study population for this prospective cohort study was singleton newborns delivered to working mothers in the industrial community of Mončegorsk in the period 1973-2005. Occupational information and characteristics of the women and their newborns was obtained from the local population-based birth register. Results The 597 women employed as painters, painter-plasterers or spoolers had 712 singleton births, whereof 31 (4.4% were perinatally diagnosed with 37 malformations. Among the 10 561 newborns in the group classified as non-exposed, 397 (3.9% had one or more malformations. The overall prevalence in the exposed group was 520/10 000 births [95% confidence limits (CL: 476, 564], and 436/10 000 births (95% CL: 396, 476 in the unexposed. Adjusted for young maternal age, smoking during pregnancy, maternal congenital malformation and year of birth, the odds ratio (OR was 1.24 (95% CL: 0.85, 1.82; for multiple anomalies it was 1.54 (95% CL: 0.66, 3.59. The largest organ-system specific difference in prevalence between the two groups was observed for malformations of the circulatory system: 112/10 000 (95% CL: 35, 190 in the exposed group, and 42/10 000 (95% CL: 29, 54 in the unexposed, with an adjusted OR of 2.03 (95% CL: 0.85, 4.84. The adjusted ORs for malformations of the genital organs and musculoskeletal system were 2.24 (95% CI: 0.95, 5.31 and 1.12 (95% CI: (0.62, 2.02, respectively. Conclusion There appeared to be a higher risk of malformations of the circulatory system and genital organs at birth among newborns to women in occupations with organic solvent exposure during early

  3. Infrared studies of polyacrylonitrile-based polymer electrolytes incorporated with lithium bis(trifluoromethane)sulfonimide and urea as deep eutectic solvent

    Science.gov (United States)

    Sim, L. N.; Yahya, R.; Arof, A. K.

    2016-06-01

    In this work, urea is introduced into polyacrylonitrile (PAN)-based polymer electrolyte containing lithium bis(trifluoromethane)sulfonimide (LiTFSI) to form a deep eutectic solvent with urea and LiTFSI in the mole ratio of 1:3. The ambient ionic conductivity of the polymer electrolyte film is enhanced from 2.54 × 10-4 S cm-1 to 3.82 × 10-3 S cm-1 with the addition of urea. Infrared studies has revealed that urea interacts with the LiTFSI through coordination of Li+ ions onto the carbonyl (Cdbnd O) group of urea, and hydrogen bonding possibly to the O atoms in the SO2 groups of TFSI- ions. Hydrogen bonding interactions of urea with DMF and PAN are also evident. The enhancement in conductivity is believed to be due to urea being involved in the dissociation of LiTFSI and its role as an additional ion conduction pathway through its carbonyl group.

  4. Solvent Extraction Developments in Southern Africa

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The largest solvent-extraction plant in the world at the time, the Nchanga Copper Operation, was in Zambia. The first commercial process using solvent extraction for the refining of the platinum-group metals was in South Africa. More recently, the Southern African region has seen the implementation of solvent extraction for other base metals, precious metals, and specialty metals. These include the world firsts of primary production of zinc at Skorpion Zinc in Namibia and the large-scale refining of gold by Harmony Gold in South Africa. Several other flowsheets that use solvent-extraction technology are currently under commissioning, development, or feasibility study for implementation in this part of the world, including those for the recovery of copper, cobalt, nickel, tantalum, and niobium.

  5. [Shoe factory workers, solvents and health].

    Science.gov (United States)

    Foà, Vito; Martinotti, Irene

    2012-01-01

    Exposure to organic solvents in footwear manufacturing industry came from the glues used adhering the shoe parts to each other. Benzene was the first solvent used in shoe factories until the evidence of its capacity to cause leukaemia. Then, the demonstration that exposure to n-hexane was related to distal polyneuropathy limited the use of this substance. After that, results of neurotoxicological studies conducted on workers exposed to different mixtures of organic solvents make necessary prevention measure directed to a progressive reduction of air dispersion of these chemicals. Today exposure to solvents in workplaces is regulated by health based exposure limit values that should warranty absence of central nervous system effects. One of the most important rules of occupational medicine is verify that these exposure levels are really health protective also for workers with increased susceptibility. PMID:22697025

  6. Automated solvent concentrator

    Science.gov (United States)

    Griffith, J. S.; Stuart, J. L.

    1976-01-01

    Designed for automated drug identification system (AUDRI), device increases concentration by 100. Sample is first filtered, removing particulate contaminants and reducing water content of sample. Sample is extracted from filtered residue by specific solvent. Concentrator provides input material to analysis subsystem.

  7. Organic solvent topical report

    Energy Technology Data Exchange (ETDEWEB)

    Cowley, W.L.

    1998-04-30

    This report is the technical basis for the accident and consequence analyses used in the Hanford Tank Farms Basis for Interim Operation. The report also contains the scientific and engineering information and reference material needed to understand the organic solvent safety issue. This report includes comments received from the Chemical Reactions Subcommittee of the Tank Advisory Panel.

  8. Organic solvent topical report

    Energy Technology Data Exchange (ETDEWEB)

    COWLEY, W.L.

    1999-05-13

    This report provides the basis for closing the organic solvent safety issue. Sufficient information is presented to conclude that risk posed by an organic solvent fire is within risk evaluation guidelines. This report updates information contained in Analysis of Consequences of Postulated Solvent Fires in Hanford Site Waste Tanks. WHC-SD-WM-CN-032. Rev. 0A (Cowley et al. 1996). However, this document will not replace Cowley et al (1996) as the primary reference for the Basis for Interim Operation (BIO) until the recently submitted BIO amendment (Hanson 1999) is approved by the US Department of Energy. This conclusion depends on the use of controls for preventing vehicle fuel fires and for limiting the use of flame cutting in areas where hot metal can fall on the waste surface.The required controls are given in the Tank Waste Remediation System Technical Safety Requirements (Noorani 1997b). This is a significant change from the conclusions presented in Revision 0 of this report. Revision 0 of this calcnote concluded that some organic solvent fire scenarios exceeded risk evaluation guidelines, even with controls imposed.

  9. Organic solvent topical report

    International Nuclear Information System (INIS)

    This report provides the basis for closing the organic solvent safety issue. Sufficient information is presented to conclude that risk posed by an organic solvent fire is within risk evaluation guidelines. This report updates information contained in Analysis of Consequences of Postulated Solvent Fires in Hanford Site Waste Tanks. WHC-SD-WM-CN-032. Rev. 0A (Cowley et al. 1996). However, this document will not replace Cowley et al (1996) as the primary reference for the Basis for Interim Operation (BIO) until the recently submitted BIO amendment (Hanson 1999) is approved by the US Department of Energy. This conclusion depends on the use of controls for preventing vehicle fuel fires and for limiting the use of flame cutting in areas where hot metal can fall on the waste surface.The required controls are given in the Tank Waste Remediation System Technical Safety Requirements (Noorani 1997b). This is a significant change from the conclusions presented in Revision 0 of this report. Revision 0 of this calcnote concluded that some organic solvent fire scenarios exceeded risk evaluation guidelines, even with controls imposed

  10. Organic solvent topical report

    International Nuclear Information System (INIS)

    This report is the technical basis for the accident and consequence analyses used in the Hanford Tank Farms Basis for Interim Operation. The report also contains the scientific and engineering information and reference material needed to understand the organic solvent safety issue. This report includes comments received from the Chemical Reactions Subcommittee of the Tank Advisory Panel

  11. Hazardous Solvent Substitution Data System tutorial

    International Nuclear Information System (INIS)

    This manual is the tutorial for the Hazardous Solvent Substitution Data System (HSSDS), an online, comprehensive system of information on alternatives to hazardous solvents and related subjects. The HSSDS data base contains product information, material safety data sheets, toxicity reports, usage reports, biodegradable data, product chemical element lists, and background information on solvents. HSSDS use TOPIC reg-sign to search for information based on a query defined by the user. TOPIC provides a full text retrieval of unstructured source documents. In this tutorial, a series of lessons is provided that guides the user through basic steps common to most queries performed with HSSDS. Instructions are provided for both window-based and character-based applications

  12. Ab initio study of solvent-dependent one-, two- and three-photon absorption properties of PRODAN-based chemo-sensors

    Indian Academy of Sciences (India)

    Md Mehboob Alam; Mausumi Chattopadhyaya

    2014-07-01

    In this work, we study the solvent-dependent one-, two- and three-photon absorption (1PA, 2PA and 3PA) properties of 2-propionyl-6-dimethylamino naphthalene (PRODAN) and three newly synthesized20 cyclopenta[b]naphthalene derivatives, in gas phase and three different solvents, namely cyclohexane, dichloromethane and ethanol. A comparison between the calculated and the available experimental data shows that the results obtained with B3LYP/cc-pVDZ level of theory matches well with the experimental absorption data for all of these compounds. The 2P and 3P transition probabilities, for all of these systems, are found to be maximum in solvents of intermediate polarity (here, dichloromethane), which is in accordance with the experimental observation for various other systems. All the 1P, 2P and 3P transition probabilities are found to be the maximum for PRODAN as compared to other three molecules in both the gas as well as the different solvent phases (except for 3PA in gas and cyclohexane solvents). We have explained these results by meticulously inspecting the components of different transition moment vectors and the tensor elements involved.

  13. An attempt towards simultaneous biobased solvent based extraction of proteins and enzymatic saccharification of cellulosic materials from distiller's grains and solubles.

    Science.gov (United States)

    Datta, Saurav; Bals, B D; Lin, Yupo J; Negri, M C; Datta, R; Pasieta, L; Ahmad, Sabeen F; Moradia, Akash A; Dale, B E; Snyder, Seth W

    2010-07-01

    Distiller's grains and solubles (DGS) is the major co-product of corn dry mill ethanol production, and is composed of 30% protein and 30-40% polysaccharides. We report a strategy for simultaneous extraction of protein with food-grade biobased solvents (ethyl lactate, d-limonene, and distilled methyl esters) and enzymatic saccharification of glucan in DGS. This approach would produce a high-value animal feed while simultaneously producing additional sugars for ethanol production. Preliminary experiments on protein extraction resulted in recovery of 15-45% of the protein, with hydrophobic biobased solvents obtaining the best results. The integrated hydrolysis and extraction experiments showed that biobased solvent addition did not inhibit hydrolysis of the cellulose. However, only 25-33% of the total protein was extracted from DGS, and the extracted protein largely resided in the aqueous phase, not the solvent phase. We hypothesize that the hydrophobic solvent could not access the proteins surrounded by the aqueous phase inside the fibrous structure of DGS due to poor mass transfer. Further process improvements are needed to overcome this obstacle.

  14. Simultaneous dispersive liquid-liquid microextraction based on a low-density solvent and derivatization followed by gas chromatography for the simultaneous determination of chloroanisoles and the precursor 2,4,6-trichlorophenol in water samples.

    Science.gov (United States)

    Bai, Xiuzhi; Zhang, Ting; Li, Haipu; Yang, Zhaoguang

    2016-06-01

    Chloroanisoles, particularly 2,4,6-trichloroanisole, are commonly identified as major taste and odor compounds in water. In the present study, a simple and efficient method was established for the simultaneous determination of chloroanisoles and the precursor 2,4,6-trichlorophenol in water by using low-density-solvent-based simultaneous dispersive liquid-liquid microextraction and derivatization followed by gas chromatography with electron capture detection. 2,4-Dichloroanisole, 2,6-dichloroanisole, 2,4,6-trichloroanisole, 2,3,4-trichloroanisole, and 2,3,6-trichloroanisole were the chloroanisoles evaluated. Several important parameters of the extraction-derivatization procedures, including the types and volumes of extraction solvent and disperser solvent, concentrations of derivatization agent and base, salt addition, extraction-derivatization time, and temperature were optimized. Under the optimized conditions (80 μL of isooctane as extraction solvent, 500 μL of methanol as disperser solvent, 60 μL of acetic anhydride as derivatization agent, 0.75% of Na2 CO3 addition w/v, extraction-derivatization temperature of 25°C, without salt addition), a good linearity of the calibration curve was observed by the square of correlation coefficients (R(2) ) ranging from 0.9936 to 0.9992. Repeatability and reproducibility of the method were < 4.5% and <7.3%, respectively. Recovery rates ranged from 85.2 to 101.4%, and limits of detection ranged from 3.0 to 8.7 ng/L. The proposed method was applied successfully for the determination of chloroanisoles and 2,4,6-trichlorophenol in water samples.

  15. "Abnormal" salt and solvent effects on anion/cation electron-transfer reactions: an interpretation based on Marcus-Hush treatment.

    Science.gov (United States)

    Garcia-Fernandez, E; Prado-Gotor, R; Sanchez, F

    2005-08-11

    Salt and solvent effects on the kinetics of the reactions [Fe(CN)6]3- + [Ru(NH3)5pz](2+) right arrow over left arrow [Fe(CN)6]4- + [Ru(NH3)5pz]3+ (pz = pyrazine) have been studied through T-jump measurements. The forward and reverse reactions show different behaviors: "abnormal" salt and solvent effects in the first case and normal effects in the second one. These facts imply an asymmetric behavior of anion/cation reactions depending on the charge of the oxidant. The results can be rationalized by using the Marcus-Hush treatment for electron-transfer reactions.

  16. Solvent Immersion Imprint Lithography

    Energy Technology Data Exchange (ETDEWEB)

    Vasdekis, Andreas E.; Wilkins, Michael J.; Grate, Jay W.; Kelly, Ryan T.; Konopka, Allan; Xantheas, Sotiris S.; Chang, M. T.

    2014-06-21

    The mechanism of polymer disolution was explored for polymer microsystem prototyping, including microfluidics and optofluidics. Polymer films are immersed in a solvent, imprinted and finally brought into contact with a non-modified surface to permanently bond. The underlying polymer-solvent interactions were experimentally and theoretically investigated, and enabled rapid polymer microsystem prototyping. During imprinting, small molecule integration in the molded surfaces was feasible, a principle applied to oxygen sensing. Polystyrene (PS) was employed for microbiological studies at extreme environmental conditions. The thermophile anaerobe Clostridium Thermocellum was grown in PS pore-scale micromodels, revealing a double mean generation lifetime than under ideal culture conditions. Microsystem prototyping through directed polymer dissolution is simple and accessible, while simultaneous patterning, bonding, and surface/volume functionalization are possible in less than one minute.

  17. Poor-solvent polyelectrolytes

    International Nuclear Information System (INIS)

    Using extensive molecular dynamics simulations we study the behaviour of polyelectrolytes (PEs) in poor solvents, explicitly taking the counterions into account. The resulting pearl-necklace structures are subject to strong conformational fluctuations. These lead to small signatures in the form factor and the force-extension relation, which is a severe obstacle to experimental observations. In addition, we study how the necklace collapses as a function of the Bjerrum length. Finally, we demonstrate that the position of the first peak in the inter-chain structure factor varies with the monomer density as ∼ ρm0.35 for all densities, which shows a pertinent different behaviour as compared to that of PE solutions in good solvent

  18. A comparative study on the thermophysical properties for two bis[(trifluoromethyl)sulfonyl]imide-based ionic liquids containing the trimethyl-sulfonium or the trimethyl-ammonium cation in molecular solvents.

    Science.gov (United States)

    Couadou, Erwan; Jacquemin, Johan; Galiano, Hervé; Hardacre, Christopher; Anouti, Mérièm

    2013-02-01

    Herein, we present a comparative study of the thermophysical properties of two homologous ionic liquids, namely, trimethyl-sulfonium bis[(trifluoromethyl)sulfonyl]imide, [S(111)][TFSI], and trimethyl-ammonium bis[(trifluoromethyl)sulfonyl]imide, [HN(111)][TFSI], and their mixtures with propylene carbonate, acetonitrile, or gamma butyrolactone as a function of temperature and composition. The influence of solvent addition on the viscosity, conductivity, and thermal properties of IL solutions was studied as a function of the solvent mole fraction from the maximum solubility of IL, x(s), in each solvent to the pure solvent. In this case, x(s) is the composition corresponding to the maximum salt solubility in each liquid solvent at a given temperature from 258.15 to 353.15 K. The effect of temperature on the transport properties of each binary mixture was then investigated by fitting the experimental data using Arrhenius' law and the Vogel-Tamman-Fulcher (VTF) equation. The experimental data shows that the residual conductivity at low temperature, e.g., 263.15 K, of each binary mixture is exceptionally high. For example, conductivity values up to 35 and 42 mS·cm(-1) were observed in the case of the [S(111)][TFSI] + ACN and [HN(111)][TFSI] + ACN binary mixtures, respectively. Subsequently, a theoretical approach based on the conductivity and on the viscosity of electrolytes was formulated by treating the migration of ions as a dynamical process governed by ion-ion and solvent-ion interactions. Within this model, viscosity data sets were first analyzed using the Jones-Dole equation. Using this theoretical approach, excellent agreement was obtained between the experimental and calculated conductivities for the binary mixtures investigated at 298.15 K as a function of the composition up to the maximum solubility of the IL. Finally, the thermal characterization of the IL solutions, using DSC measurements, showed a number of features corresponding to different solid

  19. Hazardous solvent substitution

    International Nuclear Information System (INIS)

    Eliminating hazardous solvents is good for the environment, worker safety, and the bottom line. However, even though we are motivated to find replacements, the big question is 'What can we use as replacements for hazardous solvents?'You, too, can find replacements for your hazardous solvents. All you have to do is search for them. Search through the vendor literature of hundreds of companies with thousands of products. Ponder the associated material safety data sheets, assuming of course that you can obtain them and, having obtained them, that you can read them. You will want to search the trade magazines and other sources for product reviews. You will want to talk to users about how well the product actually works. You may also want to check US Environmental Protection Agency (EPA) and other government reports for toxicity and other safety information. And, of course, you will want to compare the product's constituent chemicals with the many hazardous constituency lists to ensure the safe and legal use of the product in your workplace

  20. Next Generation Solvent Performance in the Modular Caustic Side Solvent Extraction Process - 15495

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Tara E. [Savannah River Remediation, LLC., Aiken, SC (United States); Scherman, Carl [Savannah River Remediation, LLC., Aiken, SC (United States); Martin, David [Savannah River Remediation, LLC., Aiken, SC (United States); Suggs, Patricia [Savannah River Site (SRS), Aiken, SC (United States)

    2015-01-14

    Changes to the Modular Caustic Side Solvent Extraction Unit (MCU) flow-sheet were implemented in the facility. Implementation included changing the scrub and strip chemicals and concentrations, modifying the O/A ratios for the strip, scrub, and extraction contactor banks, and blending the current BoBCalixC6 extractant-based solvent in MCU with clean MaxCalix extractant-based solvent. During the successful demonstration period, the MCU process was subject to rigorous oversight to ensure hydraulic stability and chemical/radionuclide analysis of the key process tanks (caustic wash tank, solvent hold tank, strip effluent hold tank, and decontaminated salt solution hold tank) to evaluate solvent carryover to downstream facilities and the effectiveness of cesium removal from the liquid salt waste. Results indicated the extraction of cesium was significantly more effective with an average Decontamination Factor (DF) of 1,129 (range was 107 to 1,824) and that stripping was effective. The contactor hydraulic performance was stable and satisfactory, as indicated by contactor vibration, contactor rotational speed, and flow stability; all of which remained at or near target values. Furthermore, the Solvent Hold Tank (SHT) level and specific gravity was as expected, indicating that solvent integrity and organic hydraulic stability were maintained. The coalescer performances were in the range of processing results under the BOBCalixC6 flow sheet, indicating negligible adverse impact of NGS deployment. After the Demonstration period, MCU began processing via routine operations. Results to date reiterate the enhanced cesium extraction and stripping capability of the Next Generation Solvent (NGS) flow sheet. This paper presents process performance results of the NGS Demonstration and continued operations of MCU utilizing the blended BobCalixC6-MaxCalix solvent under the NGS flowsheet.

  1. Method for Selection of Solvents for Promotion of Organic Reactions

    DEFF Research Database (Denmark)

    Gani, Rafiqul; Jiménez-González, Concepción; Constable, David J.C.

    2005-01-01

    A method to select appropriate green solvents for the promotion of a class of organic reactions has been developed. The method combines knowledge from industrial practice and physical insights with computer-aided property estimation tools for selection/design of solvents. In particular, it employs...... estimates of thermodynamic properties to generate a knowledge base of reaction, solvent and environment related properties that directly or indirectly influence the rate and/or conversion of a given reaction. Solvents are selected using a rules-based procedure where the estimated reaction-solvent properties...... and the solvent-environmental properties guide the decision making process. The current method is applicable only to organic reactions occurring in the liquid phase. Another gas or solid phase, which may or may not be at equilibrium with the reacting liquid phase, may also be present. The objective of this method...

  2. Effect of Solvent and Acid-Base on Palladium(ll)-catalyzed Dicarbonylation of Terminal Acetylenes: a General, Efficient andStereoselective Synthesis of Maleic Diesters and Maleic Anhydrides

    Institute of Scientific and Technical Information of China (English)

    JIANG, Huan-Feng; LI, JiN-Heng; CHEN, Ming-Cai

    2001-01-01

    The productions of maleic diesters and maleic anhydrises depend on the effect of solvint and acid-bade of solvent and acid-base in palladium-catalyzed dicarbonylation of terminal acetylenes. For primaryand secondary alcohol in benzene.only maleic diesters wereobtained stereospecifically from the sicabonylation ofacetylenes in the presence of PdCl2,and NaHCO3.For tERTIARy alcohols,maleic anhydrides were synthesized selectively.

  3. Silica-based sulfonic acid (MCM-41-SO3H: a practical and efficient catalyst for the synthesis of highly substituted quinolines under solvent-free conditions at ambient temperature

    Directory of Open Access Journals (Sweden)

    Ali Maleki

    2014-06-01

    Full Text Available In this work, a variety of highly substituted quinolines were readily synthesized via Friedlander annulation using Brönsted acid silica-based sulfonic acid as a modified catalyst under solvent-free conditions at room temperature. This efficient procedure has the advantages of giving the target compounds in high yields, short reaction times, simple workup procedure, reusability of the catalyst, and environmentally benign conditions.

  4. Solvent cavitation under solvophobic confinement.

    Science.gov (United States)

    Ashbaugh, Henry S

    2013-08-14

    The stability of liquids under solvophobic confinement can tip in favor of the vapor phase, nucleating a liquid-to-vapor phase transition that induces attractive forces between confining surfaces. In the case of water adjacent to hydrophobic surfaces, experimental and theoretical evidence support confinement-mediated evaporation stabilization of biomolecular and colloidal assemblies. The macroscopic thermodynamic theory of cavitation under confinement establishes the connection between the size of the confining surfaces, interfacial free energies, and bulk solvent pressure with the critical evaporation separation and interfacial forces. While molecular simulations have confirmed the broad theoretical trends, a quantitative comparison based on independent measurements of the interfacial free energies and liquid-vapor coexistence properties has, to the best of our knowledge, not yet been performed. To overcome the challenges of simulating a large number of systems to validate scaling predictions for a three-dimensional fluid, we simulate both the forces and liquid-vapor coexistence properties of a two-dimensional Lennard-Jones fluid confined between solvophobic plates over a range of plate sizes and reservoir pressures. Our simulations quantitatively agree with theoretical predictions for solvent-mediated forces and critical evaporation separations once the length dependence of the solvation free energy of an individual confining plate is taken into account. The effective solid-liquid line tension length dependence results from molecular scale correlations for solvating microscopic plates and asymptotically decays to the macroscopic value for plates longer than 150 solvent diameters. The success of the macroscopic thermodynamic theory at describing two-dimensional liquids suggests application to surfactant monolayers to experimentally confirm confinement-mediated cavitation. PMID:23947875

  5. Advanced integrated solvent extraction systems

    Energy Technology Data Exchange (ETDEWEB)

    Horwitz, E.P.; Dietz, M.L.; Leonard, R.A. [Argonne National Lab., IL (United States)

    1997-10-01

    Advanced integrated solvent extraction systems are a series of novel solvent extraction (SX) processes that will remove and recover all of the major radioisotopes from acidic-dissolved sludge or other acidic high-level wastes. The major focus of this effort during the last 2 years has been the development of a combined cesium-strontium extraction/recovery process, the Combined CSEX-SREX Process. The Combined CSEX-SREX Process relies on a mixture of a strontium-selective macrocyclic polyether and a novel cesium-selective extractant based on dibenzo 18-crown-6. The process offers several potential advantages over possible alternatives in a chemical processing scheme for high-level waste treatment. First, if the process is applied as the first step in chemical pretreatment, the radiation level for all subsequent processing steps (e.g., transuranic extraction/recovery, or TRUEX) will be significantly reduced. Thus, less costly shielding would be required. The second advantage of the Combined CSEX-SREX Process is that the recovered Cs-Sr fraction is non-transuranic, and therefore will decay to low-level waste after only a few hundred years. Finally, combining individual processes into a single process will reduce the amount of equipment required to pretreat the waste and therefore reduce the size and cost of the waste processing facility. In an ongoing collaboration with Lockheed Martin Idaho Technology Company (LMITCO), the authors have successfully tested various segments of the Advanced Integrated Solvent Extraction Systems. Eichrom Industries, Inc. (Darien, IL) synthesizes and markets the Sr extractant and can supply the Cs extractant on a limited basis. Plans are under way to perform a test of the Combined CSEX-SREX Process with real waste at LMITCO in the near future.

  6. Properties and thermal behavior of natural deep eutectic solvents

    OpenAIRE

    Craveiro, R.; Aroso, Ivo Manuel Ascensão; Flammia, V.; Carvalho, T.; Viciosa, M. T.; Dionísio, M.; Barreiros, S.; Reis, R. L.; Duarte, Ana Rita C.; Paiva, A.

    2016-01-01

    Natural deep eutectic solvents (NADES) have shown to be promising sustainable media for a wide range of applications. Nonetheless, very limited data is available on the properties of these solvents. A more comprehensive body of data on NADES is required for a deeper understanding of these solvents at molecular level, which will undoubtedly foster the development of new applications. NADES based on choline chloride, organic acids, amino acids and sugars were prepared, and their density, therma...

  7. Alcohols as hydrogen-donor solvents for treatment of coal

    Science.gov (United States)

    Ross, David S.; Blessing, James E.

    1981-01-01

    A method for the hydroconversion of coal by solvent treatment at elevated temperatures and pressure wherein an alcohol having an .alpha.-hydrogen atom, particularly a secondary alcohol such as isopropanol, is utilized as a hydrogen donor solvent. In a particular embodiment, a base capable of providing a catalytically effective amount of the corresponding alcoholate anion under the solvent treatment conditions is added to catalyze the alcohol-coal reaction.

  8. Electrospinning of Grooved Polystyrene Fibers: Effect of Solvent Systems

    Science.gov (United States)

    Liu, Wanjun; Huang, Chen; Jin, Xiangyu

    2015-05-01

    Secondary surface texture is of great significance to morphological variety and further expands the application areas of electrospun nanofibers. This paper presents the possibility of directly electrospinning grooved polystyrene (PS) fibers using both single and binary solvent systems. Solvents were classified as low boiling point solvent (LBPS): dichloromethane (DCM), acetone (ACE), and tetrahydrofuran (THF); high boiling point solvent (HBPS): N, N-dimethylformamide (DMF) and cyclohexanone (CYCo); and non-solvent (NS): 1-butanol (BuOH). By the systematic selection and combination of these solvents at given parameters, we found that single solvent systems produced non-grooved fibers. LBPS/DMF solvent systems resulted in fibers with different grooved textures, while LBPS/CYCo led to fibers with double grooved texture. Grooved fibers can also be fabricated from LBPS/LBPS, NS/LBPS, and NS/HBPS systems under specific conditions. The results indicated that the difference of evaporation rate (DER) between the two solvents played a key role in the formation of grooved texture. The formation of this unique texture should be attributed to three separate mechanisms, namely void-based elongation, wrinkle-based elongation, and collapsed jet-based elongation. Our findings can serve as guidelines for the preparation of ultrafine fibers with grooved secondary texture.

  9. Occupational solvent exposure and cognition

    Science.gov (United States)

    Sabbath, E.L.; Glymour, M.M.; Berr, C.; Singh-Manoux, A.; Zins, M.; Goldberg, M.

    2012-01-01

    Objective: Chronic occupational solvent exposure is associated with long-term cognitive deficits. Cognitive reserve may protect solvent-exposed workers from cognitive impairment. We tested whether the association between chronic solvent exposure and cognition varied by educational attainment, a proxy for cognitive reserve. Methods: Data were drawn from a prospective cohort of French national gas and electricity (GAZEL) employees (n = 4,134). Lifetime exposure to 4 solvent types (chlorinated solvents, petroleum solvents, benzene, and nonbenzene aromatic solvents) was assessed using a validated job-exposure matrix. Education was dichotomized at less than secondary school or below. Cognitive impairment was defined as scoring below the 25th percentile on the Digit Symbol Substitution Test at mean age 59 (SD 2.8; 88% of participants were retired at testing). Log-binomial regression was used to model risk ratios (RRs) for poor cognition as predicted by solvent exposure, stratified by education and adjusted for sociodemographic and behavioral factors. Results: Solvent exposure rates were higher among less-educated patients. Within this group, there was a dose-response relationship between lifetime exposure to each solvent type and RR for poor cognition (e.g., for high exposure to benzene, RR = 1.24, 95% confidence interval 1.09–1.41), with significant linear trends (p < 0.05) in 3 out of 4 solvent types. Recency of solvent exposure also predicted worse cognition among less-educated patients. Among those with secondary education or higher, there was no significant or near-significant relationship between any quantification of solvent exposure and cognition. Conclusions: Solvent exposure is associated with poor cognition only among less-educated individuals. Higher cognitive reserve in the more-educated group may explain this finding. PMID:22641403

  10. A novel digestion method based on a choline chloride–oxalic acid deep eutectic solvent for determining Cu, Fe, and Zn in fish samples

    Energy Technology Data Exchange (ETDEWEB)

    Habibi, Emadaldin [Department of Marine Chemistry, Faculty of Marine Science, Khorramshahr University of Marine Science and Technology, P.O. BOX 669, Khorramshahr (Iran, Islamic Republic of); Ghanemi, Kamal, E-mail: Kamal.ghanemi@kmsu.ac.ir [Department of Marine Chemistry, Faculty of Marine Science, Khorramshahr University of Marine Science and Technology, P.O. BOX 669, Khorramshahr (Iran, Islamic Republic of); Marine Science Research Institute, Khorramshahr University of Marine Science and Technology, Khorramshahr (Iran, Islamic Republic of); Fallah-Mehrjardi, Mehdi [Department of Marine Chemistry, Faculty of Marine Science, Khorramshahr University of Marine Science and Technology, P.O. BOX 669, Khorramshahr (Iran, Islamic Republic of); Marine Science Research Institute, Khorramshahr University of Marine Science and Technology, Khorramshahr (Iran, Islamic Republic of); Dadolahi-Sohrab, Ali [Department of Marine Environment, Faculty of marine natural resources, Khorramshahr University of Marine Science and Technology, Khorramshahr (Iran, Islamic Republic of)

    2013-01-31

    Highlights: ► A novel digestion method: lack of concentrated acids or oxidizing reagents. ► First report of using choline chloride–oxalic acid (ChCl–Ox) for digestion. ► Complete dissolution of biological samples in ChCl–Ox for solubilization metals. ► Extraction recoveries greater than 95%: validated by the fish protein CRM. ► Successfully applied in different fish tissues (Muscle, Liver, and Gills). -- Abstract: A novel and efficient digestion method based on choline chloride–oxalic acid (ChCl–Ox) deep eutectic solvent (DES) was developed for flame atomic absorption spectrometry (FAAS) determination of Cu, Zn, and Fe in biological fish samples. Key parameters that influence analyte recovery were investigated and optimized, using the fish protein certified reference material (CRM, DORM-3) throughout the procedure. In this method, 100 mg of the sample was dissolved in ChCl–Ox (1:2, molar ratio) at 100 °C for 45 min. Then, 5.0 mL HNO{sub 3} (1.0 M) was added. After centrifugation, the supernatant solution was filtered, diluted to a known volume, and analyzed by FAAS. Under optimized conditions, an excellent agreement between the obtained results and the certified values was observed, using Student's t-test (P = 0.05); the extraction recovery of the all elements was greater than 95.3%. The proposed method was successfully applied to the determination of analytes in different tissues (muscle, liver, and gills) having a broad concentration range in a marine fish sample. The reproducibility of the method was validated by analyzing all samples by our method in a different laboratory, using inductively coupled plasma optical emission spectrometry (ICP-OES). For comparison, a conventional acid digestion (CAD) method was also used for the determination of analytes in all studied samples. The simplicity of the proposed experimental procedure, high extraction efficiency, short analysis time, lack of concentrated acids and oxidizing agents, and the

  11. A novel digestion method based on a choline chloride–oxalic acid deep eutectic solvent for determining Cu, Fe, and Zn in fish samples

    International Nuclear Information System (INIS)

    Highlights: ► A novel digestion method: lack of concentrated acids or oxidizing reagents. ► First report of using choline chloride–oxalic acid (ChCl–Ox) for digestion. ► Complete dissolution of biological samples in ChCl–Ox for solubilization metals. ► Extraction recoveries greater than 95%: validated by the fish protein CRM. ► Successfully applied in different fish tissues (Muscle, Liver, and Gills). -- Abstract: A novel and efficient digestion method based on choline chloride–oxalic acid (ChCl–Ox) deep eutectic solvent (DES) was developed for flame atomic absorption spectrometry (FAAS) determination of Cu, Zn, and Fe in biological fish samples. Key parameters that influence analyte recovery were investigated and optimized, using the fish protein certified reference material (CRM, DORM-3) throughout the procedure. In this method, 100 mg of the sample was dissolved in ChCl–Ox (1:2, molar ratio) at 100 °C for 45 min. Then, 5.0 mL HNO3 (1.0 M) was added. After centrifugation, the supernatant solution was filtered, diluted to a known volume, and analyzed by FAAS. Under optimized conditions, an excellent agreement between the obtained results and the certified values was observed, using Student's t-test (P = 0.05); the extraction recovery of the all elements was greater than 95.3%. The proposed method was successfully applied to the determination of analytes in different tissues (muscle, liver, and gills) having a broad concentration range in a marine fish sample. The reproducibility of the method was validated by analyzing all samples by our method in a different laboratory, using inductively coupled plasma optical emission spectrometry (ICP-OES). For comparison, a conventional acid digestion (CAD) method was also used for the determination of analytes in all studied samples. The simplicity of the proposed experimental procedure, high extraction efficiency, short analysis time, lack of concentrated acids and oxidizing agents, and the use of safe

  12. Solvent effects in chemistry

    CERN Document Server

    Buncel, Erwin

    2015-01-01

    This book introduces the concepts, theory and experimental knowledge concerning solvent effects on the rate and equilibrium of chemical reactions of all kinds.  It begins with basic thermodynamics and kinetics, building on this foundation to demonstrate how a more detailed understanding of these effects may be used to aid in determination of reaction mechanisms, and to aid in planning syntheses. Consideration is given to theoretical calculations (quantum chemistry, molecular dynamics, etc.), to statistical methods (chemometrics), and to modern day concerns such as ""green"" chemistry, where ut

  13. Effects of solvent and structure on the reactivity of 6-substituted nicotinic acids with diazodiphenylmethane in aprotic solvents

    Directory of Open Access Journals (Sweden)

    BRATISLAV Ž. JOVANOVIĆ

    2009-12-01

    Full Text Available The rate constants for the reactions of diazodiphenylmethane (DDM with 6-substituted nicotinic acids in aprotic solvents at 30 °C were determined. The obtained second order rate constants in aprotic solvents, together with literature data for benzoic and nicotinic acids in protic solvents, were used for the calculation of solvent effects, employing the Kamlet-Taft solvatochromic equation (linear solvation energy relationship – LSER in the form: log k = log k0 + s* + a + b. The correlations of the kinetic data were performed by means of multiple linear regression analysis taking appropriate solvent parameters. The sign of the equation coefficients (s, a and b were in agreement with the postulated reaction mechanism, and the mode of the solvent influences on the reaction rate is discussed based on the correlation results. A similar contribution of the non-specific solvent effect and electrophilic solvation was observed for all acids, while the highest contribution of nucleophilic solvation was influenced by their high acidity. Correlation analysis of the rate data with substituent p parameters in an appropriate solvent using the Hammett equation was also performed. The substituent effect on the acid reactivity was higher in aprotic solvents of higher dipolarity/polarizability. The mode of the transmission of the substituent effect is discussed in light of the contribution of solute–solvent interaction on the acid reactivity.

  14. Solvent effects on optical excitations of poly para phenylene ethynylene studied by QM/MM simulations based on Many-Body Green's Functions Theory

    CERN Document Server

    Bagheri, Behnaz; Baumeier, Björn

    2016-01-01

    Electronic excitations in dilute solutions of poly para phenylene ethynylene (poly-PPE) are studied using a QM/MM approach combining many-body Green's functions theory within the $GW$ approximation and the Bethe-Salpeter equation with polarizable force field models. Oligomers up to a length of 7.5\\,nm (10 repeat units) functionalized with nonyl side chains are solvated in toluene and water, respectively. After equilibration using atomistic molecular dynamics (MD), the system is partitioned into a quantum region (backbone) embedded into a classical (side chains and solvent) environment. Optical absorption properties are calculated solving the coupled QM/MM system self-consistently and special attention is paid to the effects of solvents. The model allows to differentiate the influence of oligomer conformation induced by the solvation from electronic effects related to local electric fields and polarization. It is found that the electronic environment contributions are negligible compared to the conformational ...

  15. Halogen-free water-immiscible ionic liquids based on tetraoctylammonium cation and dodecylsulfate and dodecylbenzenesulfonate anions, and their application as chelate extraction solvent

    OpenAIRE

    Tsukatani, Toshihide; Katano, Hajime; Tatsumi, Hirosuke; Deguchi, Mika; Hirayama, Naoki

    2006-01-01

    The tetraoctylammonium cation forms water-immiscible room temperature ionic liquids with dodecylsulfate and dodecylbenzenesulfonate anions. The ionic liquids are halogen-free and can be considered environmentally friendly solvents. At 25°C, the solubilities of water in tetraoctylammonium dodecylsulfate and tetraoctylammonium dodecylbenzenesulfonate were 2.8 and 4.0%, respectively, and the densities were 0.92 and 0.93 g cm 3. The ionic liquids formed stable interfaces with water at 25°C. The p...

  16. CO2-Binding Organic Liquids Gas Capture with Polarity-Swing-Assisted Regeneration Full Technology Feasibility Study B1 - Solvent-based Systems

    Energy Technology Data Exchange (ETDEWEB)

    Heldebrant, David J

    2014-08-31

    PNNL, Fluor Corporation and Queens University (Kingston, ON) successfully completed a three year comprehensive study of the CO2BOL water-lean solvent platform with Polarity Swing Assisted Regeneration (PSAR). This study encompassed solvent synthesis, characterization, environmental toxicology, physical, thermodynamic and kinetic property measurements, Aspen Plus™ modeling and bench-scale testing of a candidate CO2BOL solvent molecule. Key Program Findings The key program findings are summarized as follows: • PSAR favorably reduced stripper duties and reboiler temperatures with little/no impact to absorption column • >90% CO2 capture was achievable at reasonable liquid-gas ratios in the absorber • High rich solvent viscosities (up to 600 cP) were successfully demonstrated in the bench-scale system. However, the projected impacts of high viscosity to capital cost and operational limits compromised the other levelized cost of electricity benefits. • Low thermal conductivity of organics significantly increased the required cross exchanger surface area, and potentially other heat exchange surfaces. • CO2BOL had low evaporative losses during bench-scale testing • There was no evidence of foaming during bench scale testing • Current CO2BOL formulation costs project to be $35/kg • Ecotoxicity (Water Daphnia) was comparable between CO2BOL and MEA (169.47 versus 103.63 mg/L) • Full dehydration of the flue gas was determined to not be economically feasible. However, modest refrigeration (13 MW for the 550 MW reference system) was determined to be potentially economically feasible, and still produce a water-lean condition for the CO2BOLs (5 wt% steady-state water loading). • CO2BOLs testing with 5 wt% water loading did not compromise anhydrous performance behavior, and showed actual enhancement of CO2 capture performance. • Mass transfer of CO2BOLs was not greatly impeded by viscosity • Facile separation of antisolvent from lean CO2BOL was

  17. Low-density-solvent-based air-assisted liquid-liquid microextraction followed by gas chromatography with flame ionization detection for the determination of synthetic phenolic antioxidants in milk samples.

    Science.gov (United States)

    Farajzadeh, Mir Ali; Afshar Mogaddam, Mohammad Reza

    2016-03-01

    A simple and rapid sample pretreatment technique termed low-density-solvent-based air-assisted liquid-liquid microextraction has been developed for the extraction and preconcentration of three synthetic phenolic antioxidants including butylated hydroxyanisole, butylated hydroxytoluene, and tert-butyl hydroquinone from milk samples prior to their analysis by gas chromatography with flame ionization detection. In this method, initially trichloroacetic acid as a proteins precipitation agent is added to the sample, and then it is sonicated and centrifuged. The obtained aqueous phase is removed and the analytes extracted by the proposed method using a low-density organic solvent. Some important parameters such as type and volume of extraction solvent, ionic strength, pH, and centrifugation rate and time were studied. Under the optimum conditions, enrichment factors were obtained in the range of 501-614. LODs and quantification were between 0.76-1.16 and 2.66-3.96 ng mL(-1) , respectively. This method is rapid and requires less than 15 min for sample preparation. PMID:26763356

  18. A green ultrasonic-assisted liquid-liquid microextraction based on deep eutectic solvent for the HPLC-UV determination of ferulic, caffeic and cinnamic acid from olive, almond, sesame and cinnamon oil.

    Science.gov (United States)

    Khezeli, Tahere; Daneshfar, Ali; Sahraei, Reza

    2016-04-01

    A simple, inexpensive and sensitive ultrasonic-assisted liquid-liquid microextraction method based on deep eutectic solvent (UALLME-DES) was used for the extraction of three phenolic acids (ferulic, caffeic and cinnamic) from vegetable oils. In a typical experiment, deep eutectic solvent as green extraction solvent was added to n-hexane (as a typical oil medium) containing target analytes. Subsequently, the extraction was accelerated by sonication. After the extraction, phase separation (DES rich phase/n-hexane phase) was performed by centrifugation. DES rich phase (lower phase) was withdrawn by a micro-syringe and submitted to isocratic reverse-phase HPLC with UV detection. Under optimum conditions obtained by response surface methodology (RSM) and desirability function (DF), the method has good linear calibration ranges (between 1.30 and 1000 µg L(-1)), coefficients of determination (r(2)>0.9949) and low limits of detection (between 0.39 and 0.63 µg L(-1)). This procedure was successfully applied to the determination of target analytes in olive, almond, sesame and cinnamon oil samples. The relative mean recoveries ranged from 94.7% to 104.6%. PMID:26838445

  19. Organic solvent-free air-assisted liquid-liquid microextraction for optimized extraction of illegal azo-based dyes and their main metabolite from spices, cosmetics and human bio-fluid samples in one step.

    Science.gov (United States)

    Barfi, Behruz; Asghari, Alireza; Rajabi, Maryam; Sabzalian, Sedigheh

    2015-08-15

    Air-assisted liquid-liquid microextraction (AALLME) has unique capabilities to develop as an organic solvent-free and one-step microextraction method, applying ionic-liquids as extraction solvent and avoiding centrifugation step. Herein, a novel and simple eco-friendly method, termed one-step air-assisted liquid-liquid microextraction (OS-AALLME), was developed to extract some illegal azo-based dyes (including Sudan I to IV, and Orange G) from food and cosmetic products. A series of experiments were investigated to achieve the most favorable conditions (including extraction solvent: 77μL of 1-Hexyl-3-methylimidazolium hexafluorophosphate; sample pH 6.3, without salt addition; and extraction cycles: 25 during 100s of sonication) using a central composite design strategy. Under these conditions, limits of detection, linear dynamic ranges, enrichment factors and consumptive indices were in the range of 3.9-84.8ngmL(-1), 0.013-3.1μgmL(-1), 33-39, and 0.13-0.15, respectively. The results showed that -as well as its simplicity, fastness, and use of no hazardous disperser and extraction solvents- OS-AALLME is an enough sensitive and efficient method for the extraction of these dyes from complex matrices. After optimization and validation, OS-AALLME was applied to estimate the concentration of 1-amino-2-naphthol in human bio-fluids as a main reductive metabolite of selected dyes. Levels of 1-amino-2-naphthol in plasma and urinary excretion suggested that this compound may be used as a new potential biomarker of these dyes in human body.

  20. Solvent Blending Strategy to Upgrade MCU CSSX Solvent to Equivalent Next-Generation CSSX Solvent

    Energy Technology Data Exchange (ETDEWEB)

    Delmau, Laetitia Helene [ORNL; Moyer, Bruce A [ORNL

    2012-12-01

    The results of the present study have validated an equal-volume blending strategy for upgrading freshly prepared CSSX solvent to a blended solvent functionally equivalent to NG-CSSX solvent. It is shown that blending fresh CSSX solvent as currently used in MCU with an equal volume of an NG-CSSX solvent concentrate of appropriate composition yields a blended solvent composition (46.5 mM of MaxCalix, 3.5 mM of BOBCalixC6, 0.5 M of Cs-7SB, 3 mM of guanidine suppressor, and 1.5 mM of TOA in Isopar L) that exhibits equivalent batch ESS performance to that of the NG-CSSX solvent containing 50 mM of MaxCalix, 0.5 M of Cs-7SB, and 3 mM of guanidine suppressor in Isopar L. The solvent blend composition is robust to third-phase formation. Results also show that a blend containing up to 60% v/v of CSSX solvent could be accommodated with minimal risk. Extraction and density data for the effect of solvent concentration mimicking diluent evaporation or over-dilution of the equal-volume blended solvent are also given, providing input for setting operational limits. Given that the experiments employed all pristine chemicals, the results do not qualify a blended solvent starting with actual used MCU solvent, which can be expected to have undergone some degree of degradation. Consequently, further work should be considered to evaluate this risk and implement appropriate remediation if needed.

  1. 热处理对不同溶剂制备的共混体系太阳电池性能影响%Annealing treatment effects on the performances of solar cells based on different solvent blend systems

    Institute of Scientific and Technical Information of China (English)

    於黄忠; 周晓明; 邓俊裕

    2011-01-01

    The solar cells based on different solvent blends of poly(3-hexylthiophene) (P3HT) and [6,6 ]-phenyl C61-butyric acid methyl ester (PCBM) as acceptors are fabricated. Annealing treatment effects on the performances of solar cells based on different solvent blend systems are analyzed by UV-vis absorption spectroscopy and photoluminescence (PL) spectroscopy. The results show that high boiling point solvent leads to an enhanced P3HT ordering in the P3HT:PCBM blend system, and causes an increased incident light absorption and PL spectrum, which contributes to the enhancement of device performance. After 130 ~C thermal annealing, The UV-Vis absorption, PL spectrum and the performance of the device are further enhanced. The performance of the device prepared with low boiling point chloroform solvent increases obviously after thermal annealing. The solar cell prepared with chlorobenzene solvent after 130 ~C thermal annealing achieves an open circuit voltage(Voo) of O. 57 V, short circuit current density (Iso) of 8.74 mA/cm2 , fill factor (FF) of 59.2% and power conversion efficiency (PCE) of 2.95% under 100 mW/cm2 air-mass 1.5 solar simulator illumination.%本文以poly(3-hexylthiophene)(P3HT)为电子给体材料,[6,6]-phenyl C61-butyric acid methyl ester(PCBM)为电子受体材料,制备出不同溶剂形成的共混体系太阳电池.从薄膜的紫外一可见吸收光谱(uV—vis)、光致发光谱(PL)、原子力表面图形(AFM)等方面,分析了热处理对不同溶剂制备的共混体系太阳电池性能的影响.结果表明较高沸点的溶剂有利于P3HT:PCBM共混体系中P3HT的有序化排列,薄膜的紫外一可见吸收和光致发光增强,太阳电池的能量转

  2. Comparative study of solvent properties for carbon dioxide absorption

    Energy Technology Data Exchange (ETDEWEB)

    Aschenbrenner, O.; Styring, P. [University of Sheffield, Sheffield (United Kingdom)

    2010-07-01

    Several inexpensive and non-toxic solvents with low vapour pressures were investigated for their suitability as alternative solvents for the absorption of carbon dioxide from flue gas. The solvents include poly(ethylene glycol)s, poly(ethylene glycol) ethers, poly(ethylenimine) and glycerol-based substances. Solvent properties such as thermal stability, solubility of carbon dioxide and selectivity over nitrogen were investigated in a systematic study using a thermogravimetric analyser. Absorption results are reported for pure carbon dioxide and nitrogen as well as a mixture of both gases. Desorption and long-term sorption behaviour are also discussed. Glycerol and poly(ethylene glycol)s show a high solubility of carbon dioxide. Due to the high viscosity of the solvent, carbon dioxide absorption in poly(ethylenimine) is very slow in spite of the presence of favourable amine groups. PEG 300 was found to be the best solvent in this study and shows a high carbon dioxide solubility as well as good selectivity over nitrogen. The advantages of high stability, low solvent loss and low desorption energy of PEG 300 may outweigh its lower absorption capacity compared to the state-of-the-art solvent monoethanolamine, making it a potentially advantageous solvent for industrial carbon dioxide absorption processes.

  3. New Efficient Synthesis of 3,4-Dihydropyrimidin-2(1H-ones Catalyzed by Benzotriazolium-Based Ionic Liquids under Solvent-Free Conditions

    Directory of Open Access Journals (Sweden)

    Zhiqing Liu

    2016-04-01

    Full Text Available An efficient synthesis of novel 3,4-dihydropyrimidin-2(1H-ones (DHPMs and their derivatives, using Brønsted acidic ionic liquid [C2O2BBTA][TFA] as a catalyst, from the condensation of aryl aldehyde, β-ketoester and urea was described. Reactions proceeded smoothly for 40 min under solvent-free conditions and gave the desirable products with good to excellent yields (up to 99%. The catalyst could be easily recycled and reused with similar efficacies for at least six cycles.

  4. New Efficient Synthesis of 3,4-Dihydropyrimidin-2(1H)-ones Catalyzed by Benzotriazolium-Based Ionic Liquids under Solvent-Free Conditions.

    Science.gov (United States)

    Liu, Zhiqing; Ma, Rong; Cao, Dawei; Liu, Chenjiang

    2016-01-01

    An efficient synthesis of novel 3,4-dihydropyrimidin-2(1H)-ones (DHPMs) and their derivatives, using Brønsted acidic ionic liquid [C₂O₂BBTA][TFA] as a catalyst, from the condensation of aryl aldehyde, β-ketoester and urea was described. Reactions proceeded smoothly for 40 min under solvent-free conditions and gave the desirable products with good to excellent yields (up to 99%). The catalyst could be easily recycled and reused with similar efficacies for at least six cycles. PMID:27070558

  5. Sonochemical heating profile for solvents and ionic liquid doped solvents, and their application in the N-alkylation of pyrazoles.

    Science.gov (United States)

    Frizzo, Clarissa P; Bacim, Carolini; Moreira, Dayse N; Rodrigues, Leticia V; Zimmer, Geórgia C; Bonacorso, Hélio G; Zanatta, Nilo; Martins, Marcos A P

    2016-09-01

    The heating profile for 25 solvents was determined in ultrasonic probe equipment at amplitudes of 20%, 25%, and 30%. Each solvent was heated in accordance with its boiling point. The effect of vapor pressure, surface tension, and viscosity of the solvents in dissipated ultrasonic power (Up) was evaluated. Multiple regression analysis of these solvent properties and dissipated Up reveals that solvent viscosity is the property that most strongly affected dissipated Up. Experimentation involving acetonitrile doped with [BMIM][BF4] indicated faster heating than MeCN. Aprotic polar solvents such as DMSO, DMF, and MeCN were tested in the N-alkylation of pyrazoles under ultrasonic conditions. After 5min at 90°C, the reactants had been totally converted into product in these solvents. Solvents, with low dissipated Up (e.g., toluene) were tested. Conversions were lower compared to those of aprotic polar solvents. When the reactions were done in hexane, no conversion to product was observed. To check the effect of doping in solvents with low Up, [BMIM][BF4], DMSO, and DMF were selected. The conversions for toluene doped with [BMIM][BF4], DMSO, and DMF were 100%, 59%, and 25%, respectively. These conversions were greater than when done in just toluene (46%). Thus, [BMIM][BF4] was the best polar doping solvent, followed by DMSO. DMF was not considered to be a satisfactory doping solvent. No conversion was observed for reactions in the absence of base performed in DMSO, DMF, and MeCN doped with [BMIM][BF4]. PMID:27150789

  6. Determining an Efficient Solvent Extraction Parameters for Re-Refining of Waste Lubricating Oils

    OpenAIRE

    Hassan Ali Durrani; Muhammed Ibrahim Panhwar; Rafique Akthar Kazi

    2012-01-01

    Re-refining of vehicle waste lubricating oil by solvent extraction is one of the efficient and cheapest methods. Three extracting solvents MEK (Methyl-Ethyl-Ketone), 1-butanol, 2-propanol were determined experimentally for their performance based on the parameters i.e. solvent type, solvent oil ratio and extraction temperature. From the experimental results it was observed the MEK performance was highest based on the lowest oil percent losses and highest sludge removal. Further, w...

  7. Review of glycol ether and glycol ether ester solvents used in the coating industry.

    OpenAIRE

    Smith, R.L.

    1984-01-01

    Ethylene oxide-based glycol ether and glycol ether ester solvents have been used in the coatings industry for the past fifty years. Because of their excellent performance properties (evaporation rate, blush resistance, flow-out and leveling properties, solubility for coating resins, solvent activity, mild odor, good coupling ability, good solvent release) a complete line of ethylene oxide-based solvents of various molecular weights has been developed. These glycol ether and glycol ether ester...

  8. Effect of mixed solvents on P3HT:PCBM based solar cell%混合溶剂对P3HT:PCBM基太阳能电池的影响

    Institute of Scientific and Technical Information of China (English)

    杨少鹏; 李娜; 李光; 史江波; 李晓苇; 傅广生

    2013-01-01

    We fabricate solar cells based on blends of poly(3-hexylthiophene) (P3HT) as the donor and [6, 6]-phenyl-C60-butyric acid methyl ester (PCBM) as the acceptor using various solvents such as pure chlorobenzene (CB), pure chloroform (CF) and mixed solvent (CB/CF) with different ratios.We investigate the influences of various solvents and mixed solvents with different ratios on the performances of solar cells. The results show that for the device by using a mixed solvent of CB/CF (3/1), its UV-Vis absorption spectrum and external quantum efficiency show a red-shift and its AFM image shows finely structured phase segregation between P3HT and PCBM. We obtain an open circuit voltage of 0.61 V, short circuit current density of 9 mA/cm2, fill factor of 57.9%, and power conversion efficiency of 3.2% under irratiation of light with a strength of 100 mW/cm2.%以poly(3-hexylthiophene)(P3HT)为电子给体材料,[6,6]-phenyl-C60-butyric acid methyl ester (PCBM)为电子受体材料,制备了纯氯苯(CB)溶剂、纯氯仿(CF)溶剂和氯苯/氯仿(CB/CF)不同比例混合溶剂的共混体系太阳能电池.研究了不同溶剂及不同比例混合的混合溶剂对电池性能的影响.结果表明:以CB/CF(3/1)为溶剂制备的器件,紫外可见吸收光谱和器件外量子效率曲线显示出红移现象,原子力显微图表明P3HT和PCBM间形成良好的相分离结构.在100 mW/cm2强度光照射下,其开路电压Voc为0.61 V短路电流密度Jsc为9mA/cm2,填充因子FF为57.9%,能量转换效率PCE为3.2%.

  9. Catalyst-free Synthesis of Betti Bases under Solvent-free Conditions%无溶剂无催化剂条件下合成betti碱

    Institute of Scientific and Technical Information of China (English)

    张婷; 熊武鑫; 丁文强; 周忠强

    2015-01-01

    在无溶剂无催化剂条件下,无论是含有吸电子基团还是含有供电子基团的芳香醛都能与2-萘酚以及仲胺反应,短时间内以高产率生成氨基烷基萘酚.该方法实验操作简单,不需要使用催化剂和溶剂,减少了废物排放,降低了成本,是一种绿色合成氨基烷基萘酚的方法.%Aromatic aldehyde containing electron-donating and electron-withdrawing substituents was reacted with 2-naphthol and secondary amine to furnish aminoalkylnaphthols in short time with high yield under solvent-free conditions in the absence of catalyst. The advantages of these reactions were simplicity of the reaction procedure, simple work-up, catalyst-and solvent-free conditions, reducing the amount of waste, and lower cost. The present method provides a green route for synthesis of aminoalkylnaphthols.

  10. Equation for Calculating the Concentration of Solvent in Air That Discriminates between Exposure and Non-exposure Based on Biomarker Concentrations in the Urine of Workers

    Directory of Open Access Journals (Sweden)

    Kondo,Yoshiro

    2006-12-01

    Full Text Available To develop a new method for evaluating the intensity of workers’ exposures to toluene alone or toluene in mixed solvents, regression equations were calculated between the concentrations of toluene to which workers were exposed and the concentrations of hippuric acid or toluene in workers’ urine samples taken at the end of their shifts. Thereafter, the discriminant exposure concentration of the solvents in air, which was the concentration considered to discriminate exposure from non-exposure within a fi xed level of error using fi ducial ranges of individual specimens (DEC-I or using confi dence ranges of regression equation (DEC-R, was measured by a scale. The devised equations were applied to calculate DEC-I or DEC-R accurately using the formulas expressing a regression line and its fi ducial ranges or confi dence ranges. The equations can calculate not only more precise values of DEC-I or DEC-R than can be measured by a scale, but can also calculate values corresponding to any level of error. Moreover, DEC-I and DEC-R can be defi ned by the equations. The concentration capable of discriminating TLV (threshold limit value exposure from non-TLV exposure was estimated using fi ducial ranges (DTL-I and then using confi dence ranges of the regression equation (DTL-R.

  11. Solvent effects on optical excitations of poly para phenylene ethynylene studied by QM/MM simulations based on many-body Green's functions theory

    Science.gov (United States)

    Bagheri, B.; Karttunen, M.; Baumeier, B.

    2016-07-01

    Electronic excitations in dilute solutions of poly para phenylene ethynylene (poly-PPE) are studied using a QM/MM approach combining many-body Green's functions theory within the GW approximation and the Bethe-Salpeter equation with polarizable force field models. Oligomers up to a length of 7.5 nm (10 repeat units) functionalized with nonyl side chains are solvated in toluene and water, respectively. After equilibration using atomistic molecular dynamics (MD), the system is partitioned into a quantum region (backbone) embedded into a classical (side chains and solvent) environment. Optical absorption properties are calculated solving the coupled QM/MM system self-consistently and special attention is paid to the effects of solvents. The model allows to differentiate the influence of oligomer conformation induced by the solvation from electronic effects related to local electric fields and polarization. It is found that the electronic environment contributions are negligible compared to the conformational dynamics of the conjugated PPE. An analysis of the electron-hole wave function reveals a sensitivity of energy and localization characteristics of the excited states to bends in the global conformation of the oligomer rather than to the relative of phenyl rings along the backbone.

  12. Supercritical multicomponent solvent coal extraction

    Science.gov (United States)

    Corcoran, W. H.; Fong, W. S.; Pichaichanarong, P.; Chan, P. C. F.; Lawson, D. D. (Inventor)

    1983-01-01

    The yield of organic extract from the supercritical extraction of coal with larger diameter organic solvents such as toluene is increased by use of a minor amount of from 0.1 to 10% by weight of a second solvent such as methanol having a molecular diameter significantly smaller than the average pore diameter of the coal.

  13. Laboratory solvent reuse -- Liquid chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Quinlin, W.T.; Schaffer, C.L.

    1992-11-01

    The objective of this work was to develop a method for reduction of waste solvent in the Process Engineering Chemistry Laboratory. The liquid chromatographs are the largest generators of explosive-contaminated waste in the laboratory. We developed a successful process for the reuse of solvents from the liquid chromatographs and demonstrated the utility of the process in the assay of hexanitrostilbene.

  14. SOLVENT EXTRACTION OF URANIUM VALUES

    Science.gov (United States)

    Feder, H.M.; Ader, M.; Ross, L.E.

    1959-02-01

    A process is presented for extracting uranium salt from aqueous acidic solutions by organic solvent extraction. It consists in contacting the uranium bearing solution with a water immiscible dialkylacetamide having at least 8 carbon atoms in the molecule. Mentioned as a preferred extractant is dibutylacetamide. The organic solvent is usually used with a diluent such as kerosene or CCl/sub 4/.

  15. Shrinkage in propellant Manufactured by Solvent Process

    Directory of Open Access Journals (Sweden)

    K.M. Agrawal

    1991-04-01

    Full Text Available The propellant manufacturers select the dimensions of die-pin for extrusion of dough by trial and error method based on their experience. This paper presents a general equation applicable for any propellant composition processed by solvent process, in any shape, i.e., cord, monotubular or the multitubular. To illustrate the relationship, calculation for outer radius for a few typical single-base propellants is given.

  16. A New Method to Grow SiC: Solvent-Laser Heated Floating Zone

    Science.gov (United States)

    Woodworth, Andrew A.; Neudeck, Philip G.; Sayir, Ali

    2012-01-01

    The solvent-laser heated floating zone (solvent-LHFZ) growth method is being developed to grow long single crystal SiC fibers. The technique combines the single crystal fiber growth ability of laser heated floating zone with solvent based growth techniques (e.g. traveling solvent method) ability to grow SiC from the liquid phase. Initial investigations reported in this paper show that the solvent-LHFZ method readily grows single crystal SiC (retains polytype and orientation), but has a significant amount of inhomogeneous strain and solvent rich inclusions.

  17. Solvent degradation products in nuclear fuel processing solvents

    Energy Technology Data Exchange (ETDEWEB)

    Shook, H.E. Jr.

    1988-06-01

    The Savannah River Plant uses a modified Purex process to recover enriched uranium and separate fission products. This process uses 7.5% tri-n-butyl phosphate (TBP) dissolved in normal paraffin hydrocarbons for the solvent extraction of a nitric acid solution containing the materials to be separated. Periodic problems in product decontamination result from solvent degradation. A study to improve process efficiency has identified certain solvent degradation products and suggested mitigation measures. Undecanoic acid, lauric acid, and tridecanoic acid were tentatively identified as diluent degradation products in recycle solvent. These long-chain organic acids affect phase separation and lead to low decontamination factors. Solid phase extraction (SPE) was used to concentrate the organic acids in solvent prior to analysis by high performance liquid chromatography (HPLC). SPE and HPLC methods were optimized in this work for analysis of decanoic acid, undecanoic acid, and lauric acid in solvent. Accelerated solvent degradation studies with 7.5% TBP in normal paraffin hydrocarbons showed that long-chain organic acids and long-chain alkyl butyl phosphoric acids are formed by reactions with nitric acid. Degradation of both tributyl phosphate and hydrocarbon can be minimized with purified normal paraffin replacing the standard grade presently used. 12 refs., 1 fig., 3 tabs.

  18. COMPUTER AIDED SOLVENT DESIGN FOR THE ENVIRONMENT

    Science.gov (United States)

    Solvent substitution is an effective and useful means of eliminating the use of harmful solvents, but finding substitute solvents which are less harmful and as effective as currently used solvents presents significant difficulties. Solvent substitution is a form of reverse engin...

  19. New Approach to QSPR Modeling of Fullerene C60 Solubility in Organic Solvents: An Application of SMILES-Based Optimal Descriptors

    Science.gov (United States)

    Toropov, A. A.; Rasulev, B. F.; Leszczynska, D.; Leszczynski, J.

    Optimal descriptors, calculated with simplified molecular input line entry system (SMILES), have been used for modeling solubility of fullerene C60 in organic solvents. Local and global attributes of the SMILES have been involved in the modeling algorithm. Local attributes represent symbols, which are images of chemical elements ("O", "N", "Cl", "Br", etc) or chemical environment (double bonds, i.e., the " = "; triple bonds, i.e., "#", etc.) Global SMILES attributes are expressed as number of a given chemical element in given SMILES as well as superposition of chemical elements (for instance, SMILES contains both "Cl" and "Br"). Statistical characteristics of the derived model are given by n = 92, r2 = 0.8865, q2 = 0.8807, s = 0.363, F = 703 (training set); and n = 30, r2 = 0.9069, q2 = 0.8932, s = 0.399, F = 273 (test set).

  20. Exploring the aryl esterase catalysis of paraoxonase-1 through solvent kinetic isotope effects and phosphonate-based isosteric analogues of the tetrahedral reaction intermediate.

    Science.gov (United States)

    Bavec, Aljoša; Knez, Damijan; Makovec, Tomaž; Stojan, Jure; Gobec, Stanislav; Goličnik, Marko

    2014-11-01

    Although a recent study of Debord et al. in Biochimie (2014; 97:72-77) described the thermodynamics of the catalysed hydrolysis of phenyl acetate by human paraoxonase-1, the mechanistic details along the reaction route of this enzyme remain unclear. Therefore, we briefly present the solvent kinetic isotope effects on the phenyl acetate esterase activity of paraoxonase-1 and its inhibition with the phenyl methylphosphonate anion, which is a stable isosteric analogue that mimics the high-energy tetrahedral intermediate on the hydroxide-promoted hydrolysis pathway. The data show normal isotope effects, while proton inventory analysis indicates that two protons contribute to the kinetic isotope effect. Coherently, moderate competitive inhibition with the phenyl methylphosphonate anion reveals that the rate-limiting transition state suboptimally resembles the tetrahedral intermediate. The implications of these findings can be attributed to two possible reaction mechanisms that might occur during the paraoxonase-1-catalysed hydrolysis of phenyl acetate.

  1. Droplet Formation via Solvent Shifting in a Microfluidic Device

    CERN Document Server

    Hajian, Ramin

    2014-01-01

    Solvent shifting is a process in which a non-solvent is added to a solvent/solute mixture and extracts the solvent. The solvent and the non-solvent are miscible. Because of solution supersaturation a portion of the solute transforms to droplets. In this paper, based on this process, we present an investigation on droplet formation and their radial motion in a microfluidic device in which a jet is injected in a co-flowing liquid stream. Thanks to the laminar flow, the microfluidic setup enables studying diffusion mass transfer in radial direction and obtaining well-defined concentration distributions. Such profiles together with Ternary Phase Diagram (TPD) give detailed information about the conditions for droplet formation condition as well as their radial migration in the channel. The ternary system is composed of ethanol (solvent), de-ionized water (non-solvent) and divinyle benzene (solute). We employ analytical/numerical solutions of the diffusion equation to obtain concentration profiles of the component...

  2. A novel extraction method for β-carotene and other carotenoids in fruit juices using air-assisted, low-density solvent-based liquid-liquid microextraction and solidified floating organic droplets.

    Science.gov (United States)

    Sricharoen, Phitchan; Limchoowong, Nunticha; Techawongstien, Suchila; Chanthai, Saksit

    2016-07-15

    Green extraction using air-assisted, low-density solvent-based liquid-liquid microextraction and solidified floating organic droplets (AA-LDS-LLME-SFOD) prior to spectrophotometry was successfully applied for quantitation of carotenoids in fruit juices. Under optimal conditions, β-carotene could be quantified with a linear response up to a concentration of 60 μg mL(-1). The procedure was performed in a microcentrifuge tube with 40 μL of 1-dodecanol as the extraction solvent and a 1.0 mL juice sample containing 8% NaCl under seven extraction cycles of air pumping by syringe. This method was validated based on linearity (0.2-30 μg mL(-1), R(2) 0.998), limit of detection (0.04 μg mL(-1)) and limit of quantification (0.13 μg mL(-1)). The precision, expressed as the relative standard deviation (RSD) of the calibration curve slope (n=12), for inter-day and intra-day analysis was 4.85% and 7.92%, respectively. Recovery of β-carotene was in the range of 93.6-101.5%. The newly proposed method is simple, rapid and environmentally friendly, particularly as a useful screening test for food analysis. PMID:26948629

  3. The influence of a solvent on the crystal morphology of RDX

    NARCIS (Netherlands)

    Horst, J.H. ter; Geertman, R.M.; Heijden, A.E.D.M. van der; Rosmalen, G.M. van

    1999-01-01

    A solvent can have a large influence on the crystal morphology. A molecular modeling technique based on the adsorption of solvent molecules on a crystal surface has been used to predict the influence of a solvent on the morphology of RDX. The predicted morphology has been compared with the experimen

  4. Program for Assisting the Replacement of Industrial Solvents PARIS III User’s Guide

    Science.gov (United States)

    PARIS III is a third generation Windows-based computer software to assist the design of less harmful solvent replacements by estimating values of the solvent properties that characterize the static, dynamic, performance, and environmental behavior of the original solvent mixture ...

  5. Selection and design of solvents

    DEFF Research Database (Denmark)

    Gani, Rafiqul

    and design of solvents will be presented together with application examples. The selection problem is defined as finding known chemicals that match the desired functions of a solvent for a specified set of applications. The design problem is defined as finding the molecular structure (or mixture of molecules....... With increasing interest on issues such as waste, sustainability, environmental impact and green chemistry, the selection and design of solvents have become important problems that need to be addressed during chemical product-process design and development. Systematic methods and tools suitable for selection...

  6. Handbook of organic solvent properties

    CERN Document Server

    Smallwood, Ian

    2012-01-01

    The properties of 72 of the most commonly used solvents are given, tabulated in the most convenient way, making this book a joy for industrial chemists to use as a desk reference. The properties covered are those which answer the basic questions of: Will it do the job? Will it harm the user? Will it pollute the air? Is it easy to handle? Will it pollute the water? Can it be recovered or incinerated? These are all factors that need to be considered at the early stages of choosing a solvent for a new product or process.A collection of the physical properties of most commonly used solvents, their

  7. The Solvent Selection framework: solvents for organic synthesis, separation processes and ionic-organic synthesis

    DEFF Research Database (Denmark)

    Mitrofanov, Igor; Sansonetti, Sascha; Abildskov, Jens;

    2012-01-01

    problems are presented: 1) solvent selection and design for organic synthesis, 2) solvent screening and design of solvent mixtures for pharmaceutical applications and 3) ionic liquids selection and design as solvents. The application of the framework is highlighted successfully through case studies...... focusing on solvent replacement problem in organic synthesis and solvent mixture design for ibuprofen respectively....

  8. Mathematical modelling of simultaneous solvent evaporation and chemical curing in thermoset coatings: A parameter study

    DEFF Research Database (Denmark)

    Kiil, Søren

    2011-01-01

    A mathematical model, describing the curing behaviour of a two-component, solvent-based, thermoset coating, is used to conduct a parameter study. The model includes curing reactions, solvent intra-film diffusion and evaporation, film gelation, vitrification, and crosslinking. A case study...... concentration of solvent. Simulations of solvent evaporation are compared to experimental data from a previous investigation. As part of the parameter study, mechanisms of this complex coating system are discussed....

  9. Indentation of polydimethylsiloxane submerged in organic solvents

    OpenAIRE

    Hu, Yuhang; Chen, Xin; Whitesides, George McClelland; Vlassak, Joost J.; Suo, Zhigang

    2011-01-01

    This work uses a method based on indentation to characterize a polydimethylsiloxane (PDMS) elastomer submerged in an organic solvent (decane, heptane, pentane, or cyclohexane). An indenter is pressed into a disk of a swollen elastomer to a fixed depth, and the force on the indenter is recorded as a function of time. By examining how the relaxation time scales with the radius of contact, one can differentiate the poroelastic behavior from the viscoelastic behavior. By matching the relaxation c...

  10. Functionalization of graphene using deep eutectic solvents

    OpenAIRE

    Hayyan, Maan; Abo-Hamad, Ali; AlSaadi, Mohammed AbdulHakim; Hashim, Mohd Ali

    2015-01-01

    Deep eutectic solvents (DESs) have received attention in various applications because of their distinctive properties. In this work, DESs were used as functionalizing agents for graphene due to their potential to introduce new functional groups and cause other surface modifications. Eighteen different types of ammonium- and phosphonium-salt-based DESs were prepared and characterized by FTIR. The graphene was characterized by FTIR, STA, Raman spectroscopy, XRD, SEM, and TEM. Additional experim...

  11. Hansen Cleaning Solvent Research Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Environmental regulation will force current baseline  precision cleaning solvent (AK-225) to be phased out starting 2015. We plan to develop  a new...

  12. 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.

    Science.gov (United States)

    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. PMID:24672876

  13. Probing solute-solvent interaction in 1-ethyl-3-methylimidazolium-based room temperature ionic liquids: A time-resolved fluorescence anisotropy study.

    Science.gov (United States)

    Das, Sudhir Kumar; Sarkar, Moloy

    2014-03-01

    Rotational diffusion of two organic solutes, coumarin153 (C153) and 4-aminophthalimide (AP) has been investigated in four ionic liquids (ILs), viz. 1-ethyl-3-methylimidazolium trifluoroacetate (EMIMTFA), 1-ethyl-3-methylimidazolium ethylsulfate (EMIMESU), 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIMTFB) and 1-ethyl-3-methylimidazolium tetracyanoborate (EMIMTCB), as a function of temperature. Between the two probes, AP can act as hydrogen-bond-donor to the solvents having hydrogen bond acceptor ability. The results indicate that the rotational dynamics of C153 is mainly governed by the viscosity of the medium. On the other hand, the rotational motion of AP is found to be significantly hindered in the ILs depending on the nature of anions of the ILs. Rotational coupling constant values for AP in the ILs follow the order TFA > ESU > TCB > TFB. The slower rotational motion of AP in these ILs has been attributed to the specific hydrogen bonding interaction between AP and anions of ILs. PMID:24158315

  14. Solvent induced synthesis, structure and properties of coordination polymers based on 5-hydroxyisophthalic acid as linker and 1,10-phenanthroline as auxiliary ligand

    Science.gov (United States)

    Kariem, Mukaddus; Yawer, Mohd; Sheikh, Haq Nawaz

    2015-11-01

    Three new coordination polymers [Mn(hip)(phen) (H2O)]n (1), [Co(hip)(phen) (H2O)]n (2), and [Cd(hip) (phen) (H2O)]n (3) (H2hip=5-hydroxyisophthalic acid; phen=1,10-phenanthroline) have been synthesized by solvo-hydrothermal method using diethyl formamide-water (DEF-H2O) as solvent system. Single-crystal X-ray diffraction analysis reveals that all three coordination polymers 1, 2 and 3 crystallize in monoclinic space group P2/n. Metal ions are inter-connected by hydroxyisophthalate anions forming zig-zag 1D chain. 1D chains are further inter-connected by hydrogen bonding and π-π stacking interactions leading to 3D supramolecular architecture. Hydrogen-bonding and π-π stacking provide thermal stability to polymers. Compounds 1 and 2 are paramagnetic at room temperature and variable temperature magnetic moment measurements revealed weak ferromagnetic interactions between metal ions at low temperature. Compound 3 exhibits excellent photoluminescence with large Stokes shift.

  15. Determination of organophosphorus pesticides in ginseng by carbon nanotube envelope-based solvent extraction combined with ultrahigh-performance liquid chromatography mass spectrometry.

    Science.gov (United States)

    Su, Rui; Li, Dan; Wang, Xinghua; Yang, Hongmei; Shi, Xiaoyu; Liu, Shuying

    2016-06-01

    A miniature extraction envelope containing multiwall carbon nanotubes, diatomite, neutral alumina, and anhydrous magnesium sulfate was developed for the solvent extraction of organophosphorus pesticides in dried ginseng. After the powder of dried ginseng sample was introduced into the envelope, the envelope was heat sealed and sonicated in acetonitrile for the extraction and clean-up of analytes. The resulting extracts were analyzed by an ultrahigh-performance liquid chromatograph with an electrospray ion source and a quadrupole orbitrap mass spectrometer (UHPLC-ESI/Q-Orbitrap MS) under target-MS(2) mode, and the analytes were quantified by matrix-match calibration. Finally, the simultaneous identification and quantification of 19 pesticide residues were carried out by the present method. It is noteworthy that in this method the processes of extraction and clean-up for the analytes could be carried out and accomplished in one step. The recoveries and relative standard deviations (RSDs) of analytes were in the range of 82.6-110.8% and 1.0-10.6%, respectively. The limits of detection (LODs) and quantification (LOQs) for analytes were determined to be 0.08-0.29μgkg(-1) and 0.26-0.98μgkg(-1), respectively. Several pesticide residues investigated in this study were found in 4 real samples, with the concentrations lower than the maximum residue limit (0.050mgkg(-1)) established by European Union. PMID:27093495

  16. Solvent/Non-Solvent Sintering To Make Microsphere Scaffolds

    Science.gov (United States)

    Laurencin, Cato T.; Brown, Justin L.; Nair, Lakshmi

    2011-01-01

    A solvent/non-solvent sintering technique has been devised for joining polymeric microspheres to make porous matrices for use as drug-delivery devices or scaffolds that could be seeded with cells for growing tissues. Unlike traditional sintering at elevated temperature and pressure, this technique is practiced at room temperature and pressure and, therefore, does not cause thermal degradation of any drug, protein, or other biochemical with which the microspheres might be loaded to impart properties desired in a specific application. Also, properties of scaffolds made by this technique are more reproducible than are properties of comparable scaffolds made by traditional sintering. The technique involves the use of two miscible organic liquids: one that is and one that is not a solvent for the affected polymer. The polymeric microspheres are placed in a mold having the size and shape of the desired scaffold, then the solvent/non-solvent mixture is poured into the mold to fill the void volume between the microspheres, then the liquid mixture is allowed to evaporate. Some of the properties of the resulting scaffold can be tailored through choice of the proportions of the liquids and the diameter of the microspheres.

  17. Functionalization of graphene using deep eutectic solvents

    Science.gov (United States)

    Hayyan, Maan; Abo-Hamad, Ali; AlSaadi, Mohammed AbdulHakim; Hashim, Mohd Ali

    2015-08-01

    Deep eutectic solvents (DESs) have received attention in various applications because of their distinctive properties. In this work, DESs were used as functionalizing agents for graphene due to their potential to introduce new functional groups and cause other surface modifications. Eighteen different types of ammonium- and phosphonium-salt-based DESs were prepared and characterized by FTIR. The graphene was characterized by FTIR, STA, Raman spectroscopy, XRD, SEM, and TEM. Additional experiments were performed to study the dispersion behavior of the functionalized graphene in different solvents. The DESs exhibited both reduction and functionalization effects on DES-treated graphene. Dispersion stability was investigated and then characterized by UV-vis spectroscopy and zeta potential. DES-modified graphene can be used in many applications, such as drug delivery, wastewater treatment, catalysts, composite materials, nanofluids, and biosensors. To the best of our knowledge, this is the first investigation on the use of DESs for graphene functionalization.

  18. Formation of Embedded Microstructures by Thermal Activated Solvent Bonding

    CERN Document Server

    Ng, S H; Wang, Z F; Lu, A C W; Rodriguez, I; De Rooij, N

    2008-01-01

    We present a thermal activated solvent bonding technique for the formation of embedded microstrucutres in polymer. It is based on the temperature dependent solubility of polymer in a liquid that is not a solvent at room temperature. With thermal activation, the liquid is transformed into a solvent of the polymer, creating a bonding capability through segmental or chain interdiffusion at the bonding interface. The technique has advantages over the more commonly used thermal bonding due to its much lower operation temperature (30 degrees C lower than the material's Tg), lower load, as well as shorter time. Lap shear test indicated bonding shear strength of up to 2.9 MPa. Leak test based on the bubble emission technique showed that the bonded microfluidic device can withstand at least 6 bars (87 psi) of internal pressure (gauge) in the microchannel. This technique can be applied to other systems of polymer and solvent.

  19. Physical properties of a new Deep Eutectic Solvent based on lithium bis[(trifluoromethyl)sulfonyl]imide and N-methylacetamide as superionic suitable electrolyte for lithium ion batteries and electric double layer capacitors

    International Nuclear Information System (INIS)

    Highlights: • Preparation of new Deep Eutectic Solvent (DES) based on N-methylacetamide and TFSI. • Characterization of conductivity, viscosity and thermal properties of DES. • DES presents a superionic character in Walden classification. • DES is suitable electrolyte for lithium ion batteries and electric double layer capacitors. -- Abstract: Herein we present a study on the physical/chemical properties of a new Deep Eutectic Solvent (DES) based on N-methylacetamide (MAc) and lithium bis[(trifluoromethyl)sulfonyl]imide (LiTFSI). Due to its interesting properties, such as wide liquid-phase range from −60 °C to 280 °C, low vapor pressure, and high ionic conductivity up to 28.4 mS cm−1 at 150 °C and at xLiTFSI = 1/4, this solution can be practically used as electrolyte for electrochemical storage systems such as electric double-layer capacitors (EDLCs) and/or lithium ion batteries (LiBs). Firstly, relationships between its transport properties (conductivity and viscosity) as a function of composition and temperature were discussed through Arrhenius’ Law and Vogel–Tamman–Fulcher (VTF) equations, as well as by using the Walden classification. From this investigation, it appears that this complex electrolyte possesses a number of excellent transport properties, like a superionic character for example. Based on which, we then evaluated its electrochemical performances as electrolyte for EDLCs and LiBs applications by using activated carbon (AC) and lithium iron phosphate (LiFePO4) electrodes, respectively. These results demonstrate that this electrolyte has a good compatibility with both electrodes (AC and LiFePO4) in each testing cell driven also by excellent electrochemical properties in specific capacitance, rate and cycling performances, indicating that the LiTFSI/MAc DES can be a promising electrolyte for EDLCs and LiBs applications especially for those requiring high safety and stability

  20. Ultrasonic aqueous cleaning as a replacement for chlorinated solvent cleaning

    International Nuclear Information System (INIS)

    The Oak Ridge Y-12 Plant has been involved in the replacement of chlorinated solvents since 1982. One of the most successful replacement efforts has been the substitution of vapor degreasers or soak tanks using chlorinated solvents with ultrasonic cleaning using aqueous detergents. Recently, funding was obtained from the Department of Energy Office (DOE) of Technology Development to demonstrate this technology. A unit has been procured and installed in the vacuum pump shop area to replace the use of a solvent soak tank. Initially, the solvents used in the shop were CFC-113 and a commercial brand cleaner which contained both perchloroethylene and methylene chloride. While the ultrasonic unit was being procured, a terpene-based solvent was used. Generally, parts were soaked overnight in order to soften baked-on vanish. Many times, wire brushing was used to help remove remaining contamination. Initial testing with the ultrasonic cleaner indicated cleaning times of 20 min were as effective as the overnight solvent soaks in removing contamination. Wire brushing was also not required following the ultrasonic cleaning as was sometimes required with the solvent soak

  1. Handbook of green chemistry, green solvents, supercritical solvents

    CERN Document Server

    Anastas, Paul T; Jessop, Philip G

    2014-01-01

    Green Chemistry is a vitally important subject area in a world where being as green and environmentally sound as possible is no longer a luxury but a necessity. Its applications include the design of chemical products and processes that help to reduce or eliminate the use and generation of hazardous substances. The Handbook of Green Chemistry comprises 12 volumes, split into subject-specific sets as follows: Set I: Green Catalysis Set II: Green Solvents Volume 4: Supercritical Solvents Volume 5: Reactions in Water Volume 6: Ionic Liquids

  2. Impairment of colour vision in workers exposed to organic solvents

    OpenAIRE

    Semple, S.; Dick, F.; Osborne, A.; Cherrie, J; Soutar, A; Seaton, A.; Haites, N.

    2000-01-01

    OBJECTIVES—To investigate loss of colour vision related to exposure to solvents and the role of three enzyme polymorphisms in modifying the risk in exposed workers.
METHODS—A sample was studied of 68 male dockyard workers and 42 male community controls with and without neuropsychological symptoms from a previous cross sectional study. Indices of cumulative and intensity based exposure to solvents were calculated for all subjects. Alcohol, drug, and smoking histories were obtained. Colour visi...

  3. An electrolyte CPA equation of state for mixed solvent electrolytes

    DEFF Research Database (Denmark)

    Maribo-Mogensen, Bjørn; Thomsen, Kaj; Kontogeorgis, Georgios M.

    2015-01-01

    Despite great efforts over the past decades, thermodynamic modeling of electrolytes in mixed solvents is still a challenge today. The existing modeling frameworks based on activity coefficient models are data-driven and require expert knowledge to be parameterized. It has been suggested that the ...... depression. Finally, the model is applied to predict VLE, LLE, and SLE in aqueous salt mixtures as well as in mixed solvents....

  4. Redox reactions in deep eutectic solvents: characterisation and application

    OpenAIRE

    Lloyd, David

    2013-01-01

    Ionic liquids are a field of intense chemical research activity due to their potential to facilitate a wide range of chemical innovations. Due to the cost of ionic liquids alternative materials which exhibit similar properties, but are less expensive, are also the subject of interest and deep eutectic solvents are a prime example. Deep eutectic solvents are commonly based on quaternary ammonium chloride salts and therefore allow the ready dissolution of a range of metal chloride salts to ...

  5. Self-healing Microencapsulation of Biomacromolecules without Organic Solvents**

    Science.gov (United States)

    Reinhold, Samuel E.; Desai, Kashappa-Goud H.; Zhang, Li; Olsen, Karl F.

    2012-01-01

    Microencapsulation of biomacromolecules in PLGA is routinely performed with organic solvent through multiple complex steps deleterious to the biomacromolecule. The new self-healing based PLGA microencapsulation obviates micronization- and organic solvent-induced protein damage, provides very high encapsulation efficiency, exhibit stabilization and slow release of labile tetanus protein antigen, and provides long-term testosterone suppression in rats following a single injection of encapsulated leuprolide. PMID:23011773

  6. Efficient extraction and preparative separation of four main isoflavonoids from Dalbergia odorifera T. Chen leaves by deep eutectic solvents-based negative pressure cavitation extraction followed by macroporous resin column chromatography.

    Science.gov (United States)

    Li, Lu; Liu, Ju-Zhao; Luo, Meng; Wang, Wei; Huang, Yu-Yan; Efferth, Thomas; Wang, Hui-Mei; Fu, Yu-Jie

    2016-10-15

    In this study, green and efficient deep eutectic solvent-based negative pressure cavitation-assisted extraction (DES-NPCE) followed by macroporous resin column chromatography was developed to extract and separate four main isoflavonoids, i.e. prunetin, tectorigenin, genistein and biochanin A from Dalbergia odorifera T. Chen leaves. The extraction procedure was optimized systematically by single-factor experiments and a Box-Behnken experimental design combined with response surface methodology. The maximum extraction yields of prunetin, tectorigenin, genistein and biochanin A reached 1.204, 1.057, 0.911 and 2.448mg/g dry weight, respectively. Moreover, the direct enrichment and separation of four isoflavonoids in DES extraction solution was successfully achieved by macroporous resin AB-8 with recovery yields of more than 80%. The present study provides a convenient and efficient method for the green extraction and preparative separation of active compounds from plants.

  7. Cross-aldol Condensation of Cycloalkanones and Aromatic Aldehydes in the Presence of Nanoporous Silica-based Sulfonic Acid (SiO2-Pr-SO3H) under Solvent Free Conditions

    Institute of Scientific and Technical Information of China (English)

    MOHAMMADI ZIARANI Ghodsi; BADIEI Alireza; ABBASI Alireza; FARAHANI Zahra

    2009-01-01

    The aromatic aldehydes underwent cross aldol condensation with cycloalkanones in the presence of a catalytic amount of nanoporous silica-based sulfonic acid (SiO2-Pr-SO3H) under solvent-free conditions to afford the corresponding a,a'-bis(substituted benzylidene)cycloalkanones in excellent yields with short reaction time without any side reactions.This method is very general,simple and environmentally friendly in contrast with other existing methods.SiO2-Pr-SO3H was proved to be an efficient heterogeneous solid acid catalyst,which could be easily handled and removed from the reaction mixture by simple filtration,and also recovered and reused without loss of reactivity.

  8. Efficient extraction and preparative separation of four main isoflavonoids from Dalbergia odorifera T. Chen leaves by deep eutectic solvents-based negative pressure cavitation extraction followed by macroporous resin column chromatography.

    Science.gov (United States)

    Li, Lu; Liu, Ju-Zhao; Luo, Meng; Wang, Wei; Huang, Yu-Yan; Efferth, Thomas; Wang, Hui-Mei; Fu, Yu-Jie

    2016-10-15

    In this study, green and efficient deep eutectic solvent-based negative pressure cavitation-assisted extraction (DES-NPCE) followed by macroporous resin column chromatography was developed to extract and separate four main isoflavonoids, i.e. prunetin, tectorigenin, genistein and biochanin A from Dalbergia odorifera T. Chen leaves. The extraction procedure was optimized systematically by single-factor experiments and a Box-Behnken experimental design combined with response surface methodology. The maximum extraction yields of prunetin, tectorigenin, genistein and biochanin A reached 1.204, 1.057, 0.911 and 2.448mg/g dry weight, respectively. Moreover, the direct enrichment and separation of four isoflavonoids in DES extraction solution was successfully achieved by macroporous resin AB-8 with recovery yields of more than 80%. The present study provides a convenient and efficient method for the green extraction and preparative separation of active compounds from plants. PMID:27517524

  9. New observation on a class of old reactions:Chemoselectivity for the solvent-free reaction of aromatic aldehydes with alkylketones catalyzed by a double-component inorganic base system

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Solvent-free reactions of aromatic aldehydes with three representative ketones,including acetophenone,acetone and cyclohexanone,have been examined under the catalysis of a low-cost inorganic base system consisting of NaOH and K2CO3.It was found that the chemoselectivity of the reactions is in close relationship with the composition of the reactants and the doublecomponent catalyst.Under the optimized experimental conditions,1,2,3,4,5-pentasubstituted cyclohexanols,α,β-unsaturated ketones and Claisen-Schmidt bicondensation products were obtained in high yields.Two Kostanecki’s triketones were separated,The composition and structure were affirmed by X-ray crystallographic analysis.

  10. Multiple sclerosis and organic solvents

    DEFF Research Database (Denmark)

    Mortensen, J T; Brønnum-Hansen, Henrik; Rasmussen, K

    1998-01-01

    We investigated a possible causal relation between exposure to organic solvents in Danish workers (housepainters, typographers/printers, carpenters/cabinetmakers) and onset of multiple sclerosis. Data on men included in the Danish Multiple Sclerosis Register (3,241 men) were linked with data from......, and butchers. Over a follow-up period of 20 years, we observed no increase in the incidence of multiple sclerosis among men presumed to be exposed to organic solvents. It was not possible to obtain data on potential confounders, and the study design has some potential for selection bias. Nevertheless......, the study does not support existing hypotheses regarding an association between occupational exposure to organic solvents and multiple sclerosis....

  11. Solvent extraction of Southern US tar sands

    Energy Technology Data Exchange (ETDEWEB)

    Penney, W.R.

    1990-01-01

    The Department of Chemical Engineering at the University of Arkansas, in association with Diversified Petroleum Recovery, Inc. (DPR) of Little Rock, Arkansas, has been developing a solvent extraction process for the recovery of bitumen from tar sands for the past five years. The unique feature of the process is that the bitumen is recovered from the solvent by contacting with a co-solvent, which causes the bitumen to precipitate. The overall purpose of this project is to study both the technical and economic feasibility of applying this technology for recovery of bitumen from tar sands by (1) investigating the socioeconmic factors which affect (a) plant siting and (b) the market value of recovered bitumen; (2) operating a process demonstration unit at the rate of 1 lb/hr recovered bitumen while producing clean sand and recyclable solvents; and (3) determine the economic conditions which will make a bitumen recovery project economical. DPR has analyzed the historical trends of domestic production, consumption, discoveries and reserves of crude oil. They have started an investigation of the volatility in the price of crude oil and of gasoline prices and of the differential between gasoline and crude oil. DPR continues to analyze the geographical movement and demand for asphalt products. Utah does not appear economically attractive as a site for a bitumen from tar sands asphalt plant. Oklahoma sites are now being studied. This report also contains the quarterly progress report from a University of Nevada study to determine bitumen composition, oxygen uptake rates, and viscosities of Alabama and Utah bitumens. Both reports have been indexed separately for inclusion on the data base.

  12. Scenarios Evaluation Tool for Chlorinated Solvent MNA

    Energy Technology Data Exchange (ETDEWEB)

    Vangelas, Karen; Michael J. Truex; Charles J. Newell; Brian Looney

    2007-02-28

    Over the past three decades, much progress has been made in the remediation of chlorinated solvents from the subsurface. Yet these pervasive contaminants continue to present a significant challenge to the U.S. Department of Energy (DOE), other federal agencies, and other public and private organizations. The physical and chemical properties of chlorinated solvents make it difficult to rapidly reach the low concentrations typically set as regulatory limits. These technical challenges often result in high costs and long remediation time frames. In 2003, the DOE through the Office of Environmental Management funded a science-based technical project that uses the U.S. Environmental Protection Agency's technical protocol (EPA, 1998) and directives (EPA, 1999) on Monitored Natural Attenuation (MNA) as the foundation on which to introduce supporting concepts and new scientific developments that will support remediation of chlorinated solvents based on natural attenuation processes. This project supports the direction in which many site owners want to move to complete the remediation of their site(s), that being to complete the active treatment portion of the remedial effort and transition into MNA. The overarching objective of the effort was to examine environmental remedies that are based on natural processes--remedies such as Monitored Natural Attenuation (MNA) or Enhanced Attenuation (EA). The research program did identify several specific opportunities for advances based on: (1) mass balance as the central framework for attenuation based remedies, (2) scientific advancements and achievements during the past ten years, (3) regulatory and policy development and real-world experience using MNA, and (4) exploration of various ideas for integrating attenuation remedies into a systematic set of ''combined remedies'' for contaminated sites. These opportunities are summarized herein and are addressed in more detail in referenced project documents and

  13. Solvent sorting in (mixed solvent + electrolyte) systems: Time-resolved fluorescence measurements and theory

    Indian Academy of Sciences (India)

    Harun Al Rasidgazi; Hemant K Kashyap; Ranjit Biswas

    2015-01-01

    In this manuscriptwe explore electrolyte-induced modification of preferential solvation of a dipolar solute dissolved in a binary mixture of polar solvents. Composition dependence of solvation characteristics at a fixed electrolyte concentration has been followed. Binary mixtures of two different polarities have been employed to understand the competition between solute-ion and solute-solvent interactions. Time-resolved fluorescence Stokes shift and anisotropy have been measured for coumarin 153 (C153) in moderately polar (ethyl acetate + 1-propanol) and strongly polar (acetonitrile + propylene carbonate) binary mixtures at various mixture compositions, and in the corresponding 1.0M solutions of LiClO4. Both the mixtures show red shifts in C153 absorption and fluorescence emission upon increase of mole fraction of the less polar solvent component in presence of the electrolyte. In addition, measured average solvation times become slower and rotation times faster for the above change in the mixture composition. A semi-molecular theory based on solution density fluctuations has been developed and found to successfully capture the essential features of the measured Stokes shift dynamics of these complex multi-component mixtures. Dynamic anisotropy results have been analyzed by using both Stokes-Einstein-Debye (SED) and Dote-Kivelson-Schwartz (DKS) theories. The importance of local solvent structure around the dissolved solute has been stressed.

  14. Universal iso-density polarizable continuum model for molecular solvents

    CERN Document Server

    Gunceler, Deniz

    2014-01-01

    Implicit electron-density solvation models based on joint density-functional theory offer a computationally efficient solution to the problem of calculating thermodynamic quantities of solvated systems from first-principles quantum mechanics. However, despite much recent interest in such models, to date the applicability of such models to non-aqueous solvents has been limited because the determination of the model parameters requires fitting to a large database of experimental solvation energies for each new solvent considered. This work presents an alternate approach which allows development of new solvation models for a large class of protic and aprotic solvents from only simple, single-molecule ab initio calculations and readily available bulk thermodynamic data. We find that this model is accurate to nearly 1.7 kcal/mol even for solvents outside our development set.

  15. Improved Purex solvent scrubbing methods

    Energy Technology Data Exchange (ETDEWEB)

    Mailen, J.C.; Tallent, O.K.

    1984-01-01

    Studies of hydrazine and hydroxylamine salts as solvent scrubbing agents that can be decomposed into gases are summarized. Results from testing of countercurrent scrubbers and solid sorber columns that produce lesser amounts of permanent salts are reported. The status of studies of the acid-degradation of paraffin diluent and the options for removal of long-chain organic acids is given.

  16. Which solvent for olfactory testing?

    Science.gov (United States)

    Philpott, C M; Goodenough, P C; Wolstenholme, C R; Murty, G E

    2004-12-01

    The physical properties of any carrier can deteriorate over time and thus alter the results in any olfactory test. The aim of this study was to evaluate clinically potential solvents as a clean odourless carrier for olfactory testing. Sweet almond oil, pure coconut oil, pure peach kernel oil, dipropylene glycol, monopropylene glycol, mineral oil and silicone oil were studied. The experimentation was conducted in two parts. First, an olfactory device was used to conduct air through the solvents on a weekly basis using a cohort of six volunteers to assess the perceived odour of each solvent at weekly intervals. Secondly a cross-reference test was performed using small bottled solutions of phenylethyl-alcohol and 1-butanol in 10-fold dilutions to compare any perceived difference in concentrations over a period of 8 weeks. We concluded that mineral oil is the most suitable carrier for the purpose of olfactory testing, possessing many desirable characteristics of an olfactory solvent, and that silicone oil may provide a suitable alternative for odorants with which it is miscible.

  17. Nanopapers for organic solvent nanofiltration.

    OpenAIRE

    Mautner, A.; Lee, K Y; P. Lahtinen; Hakalahti, M.; Tammelin, T. (Tuija); Li, K.; Bismarck, A.

    2014-01-01

    Would it not be nice to have an organic solvent nanofiltration membrane made from renewable resources that can be manufactured as simply as producing paper? Here the production of nanofiltration membranes made from nanocellulose by applying a papermaking process is demonstrated. Manufacture of the nanopapers was enabled by inducing flocculation of nanofibrils upon addition of trivalent ions.

  18. Anthracene/phenothiazine π-conjugated sensitizers for dye-sensitized solar cells using redox mediator in organic and water-based solvents.

    Science.gov (United States)

    Lin, Ryan Yeh-Yung; Chuang, Tzu-Man; Wu, Feng-Ling; Chen, Pei-Yu; Chu, Te-Chun; Ni, Jen-Shyang; Fan, Miao-Syuan; Lo, Yih-Hsing; Ho, Kuo-Chuan; Lin, Jiann T

    2015-01-01

    Metal-free dyes (MD1 to MD5) containing an anthracene/phenothiazine unit in the spacer have been synthesized. The conversion efficiency (7.13 %) of the dye-sensitized solar cell using MD3 as the sensitizer reached approximately 85 % of the N719-based standard cell (8.47 %). The cell efficiency (8.42 %) of MD3-based dye-sensitized solar cells (DSSCs) with addition of chenodeoxycholic acid is comparable with that of N719-based standard cell. The MD3 water-based DSSCs using a dual-TEMPO (2,2,6,6-tetramethylpiperidine-N-oxyl)/iodide electrolyte exhibited very promising cell performance of 4.96 % with an excellent Voc of 0.77 V.

  19. ODC-Free Solvent Implementation Issues for Vulcanized Rubber and Bond Systems

    Science.gov (United States)

    Hodgson, James R.; McCool, Alex (Technical Monitor)

    2001-01-01

    Thiokol Propulsion has worked extensively to replace 1,1,1-trichloroethane (TCA) with ozone depleting chemicals (ODC)-free solvents for use in the manufacture of the Reusable Solid Rocket Motor (RSRM) for the Space Shuttle Program. As Thiokol has transitioned from sub-scale to full-scale testing and implementation of these new solvents, issues have been discovered which have required special attention. The original intent of Thiokol's solvent replacement strategy was to replace TCA with a single drop-in solvent for all equivalent applications. We have learned that a single candidate does not exist for replacing TCA. Solvent incompatibility with process materials has caused us to seek for niche solvents and/or processing changes that provide an ODC-free solution for special applications. This paper addresses some of the solvent incompatibilities, which have lead to processes changes and possible niche solvent usage. These incompatibilities were discovered during full-scale testing of ODC-free solvents and relate to vulcanized rubber and bond systems in the RSRM. Specifically, the following items are presented: (1) Cure effects of d-limonene based solvents on Silica Filled Ethylene Propylene Diene Monomer (SF-EPDM) rubber. During full-scale test operations, Thiokol discovered that d-limonene (terpene) based solvents inhibit the cure of EPDM rubber. Subsequent testing showed the same issue with Nitrile Butadiene Rubber (NBR). Also discussed are efforts to minimize uncured rubber exposure to solvents; and (2) Cured bond system sensitivity to ODC-free solvents. During full scale testing it was discovered that a natural rubber to steel vulcanized bond could degrade after prolonged exposure to ODC-free solvents. Follow on testing showed that low vapor pressure and residence time seemed to be most likely cause for failure.

  20. Oak Ridge K-25 Site chlorinated solvent pollution prevention opportunity assessment

    International Nuclear Information System (INIS)

    A pollution prevention opportunity assessment (PPOA) was conducted at the Oak Ridge K-25 Site to identify opportunities to reduce and better manage the use of chlorinated solvents. At the K-25 Site, 67 control areas were examined for their potential use of chlorinated solvents. Of these areas, 27 were found to be using (1) chlorinated solvents for cleaning, degreasing, and lubricating; (2) laboratory standards and solvents; and (3) test medium. Current management practices encourage the identification and use of nonhazardous chemicals, including the use of chlorinated solvents. The main pollution prevention principles are source reduction and recycling, and a number of pollution prevention options based on these principles were identified and evaluated as part of this chlorinated solvent PPOA. Source reduction options evaluated for the K-25 Site include the substitution of chlorinated solvents with nonchlorinated solvents. Recycling was identified for those areas that would benefit most from the reuse of the chlorinated solvents in use. The pollution prevention options that offer the greatest opportunity for success at the K-25 Site are the implementation of substitutes at the 10 control areas using chlorinated solvents for cleaning, degreasing, and lubrication. A change in the process may be all that is needed to eliminate the use of a chlorinated solvent. Once a decision is made to implement a substitution, the information should be communicated to all shops and laboratories. Another option to consider is the installation of recycling units to recycle the large amounts of methylene chloride used in the analytical sampling procedure

  1. Determining an Efficient Solvent Extraction Parameters for Re-Refining of Waste Lubricating Oils

    Directory of Open Access Journals (Sweden)

    Hassan Ali Durrani

    2012-04-01

    Full Text Available Re-refining of vehicle waste lubricating oil by solvent extraction is one of the efficient and cheapest methods. Three extracting solvents MEK (Methyl-Ethyl-Ketone, 1-butanol, 2-propanol were determined experimentally for their performance based on the parameters i.e. solvent type, solvent oil ratio and extraction temperature. From the experimental results it was observed the MEK performance was highest based on the lowest oil percent losses and highest sludge removal. Further, when temperature of extraction increased the oil losses percent also decreased. This is due to the solvent ability that dissolves the base oil in waste lubricating oil and determines the best SOR (Solvent Oil Ratio and extraction temperatures.

  2. Supercritical Fluid Extraction versus Traditional Solvent Extraction of Caffeine from Tea Leaves: A Laboratory-Based Case Study for an Organic Chemistry Course

    Science.gov (United States)

    Schaber, Peter M.; Larkin, Judith E.; Pines, Harvey A.; Berchou, Kelly; Wierchowski, Elizabeth; Marconi, Andrew; Suriani, Allison

    2012-01-01

    In this case-based laboratory, an instrument sales person attempts to convince an analysis laboratory of the virtues of supercritical fluid extraction (SFE). The sales person deals directly with the laboratory technicians who will make the decision. Arrangements are made to have SFE instrumentation brought into the laboratory for a comparative…

  3. Dipolar correlations in structured solvents under nanoconfinement.

    Science.gov (United States)

    Buyukdagli, Sahin; Blossey, Ralf

    2014-06-21

    We study electrostatic correlations in structured solvents confined to nanoscale systems. We derive variational equations of Netz-Orland type for a model liquid composed of finite size dipoles. These equations are solved for both dilute solvents and solvents at physiological concentrations in a slit nanopore geometry. Correlation effects are of major importance for the dielectric reduction and anisotropy of the solvent resulting from dipole image interactions and also lead to a reduction of van der Waals attractions between low dielectric bodies. Finally, by comparison with other recently developed self-consistent theories and experiments, we scrutinize the effect of solvent-membrane interactions on the differential capacitance of the charged liquid in contact with low dielectric substrates. The interfacial solvent depletion driven by solvent-image interactions plays the major role in the observed low values of the experimental capacitance data, while non-locality associated with the extended charge structure of solvent molecules only brings a minor contribution. PMID:24952564

  4. Environmental Friendly Synthesis of Novel Isatin Ketal and Isatin Schiff Base Derivatives Using Michael Addition Reaction under Solvent-Free Conditions

    Institute of Scientific and Technical Information of China (English)

    Imanzadeh, Ghotamhassan; Soltanizadeh, Zahra; Khodayari, Ali; Zamanloo, Mohammadreza; Mansoori, Yagoub; Salehzadeh, Jaber

    2012-01-01

    An efficient and simple procedure for the synthesis of novel isatin derivatives is described. Michael addition of aniline Schiff bases of isatin or p-toluidine Schiff bases of isatin to fumaric esters affords the Michael adduct com- pounds in good to high yields in the presence of K2CO3 and tetrabutylammonium bromide (TBAB) under sol- vent-free conditions. Repeating of this reaction about spiro[l,3-dioxolane-2,3'-indol]-2'(l'H)-one, as a Michael do- nor, in the presence of 1,4-diazabicyclo[2.2.2]octane (DABCO) gives Michael adducts in remarkable yields under the same conditions.

  5. Novel homo- and hetero-nuclear copper(II) complexes of tetradentate Schiff bases: Synthesis, characterization, solvent-extraction and catalase-like activity studies

    Energy Technology Data Exchange (ETDEWEB)

    Dede, Buelent [Sueleyman Demirel University, Department of Chemistry, Isparta, 32260 (Turkey)], E-mail: dbulent@fef.sdu.edu.tr; Karipcin, Fatma; Cengiz, Mustafa [Sueleyman Demirel University, Department of Chemistry, Isparta, 32260 (Turkey)

    2009-04-30

    Twelve homo- and hetero-nuclear copper(II) complexes of tetradentate Schiff base ligands containing N{sub 4} donor sets have been prepared by employing several steps. The characterization and nature of bonding of the complexes have been deduced from elemental analysis, FT-IR, molar conductivity, magnetic moment measurements and thermal analysis. The three Schiff base ligands were further identified using {sup 1}H and {sup 13}C NMR spectra. All copper(II) complexes are 1:2 electrolytes as shown by their molar conductivities ({lambda}{sub M}) in DMF and paramagnetic. The subnormal magnetic moment values of the di- and tri-nuclear complexes explained by a very strong anti-ferromagnetic interaction. The extraction ability of the ligands has been examined by the liquid-liquid extraction of selected transition metal (Mn{sup 2+}, Co{sup 2+}, Ni{sup 2+}, Cu{sup 2+}, Zn{sup 2+}, Pb{sup 2+}, Cd{sup 2+}, Hg{sup 2+}) cations. The ligands show strong binding ability toward copper(II) ion. Furthermore the homo- and hetero-nuclear copper(II) complexes were each tested for their ability to catalyse the disproportionation of hydrogen peroxide in the presence of the added base imidazole.

  6. 碳基固体酸催化剂上溶剂上条件下酮和芳香醛交叉羟醛缩合反应%Carbon-Based Solid Acid as an Efficient and Reusable Catalyst for Cross-Aldol Condensation of Ketones with Aromatic Aldehydes under Solvent-Free Conditions

    Institute of Scientific and Technical Information of China (English)

    Abbas ZALI; Kamal GHANI; Arash SHOKROLAHI; Mohammad Hossein KESHAVARZ

    2008-01-01

    Aromatic aldehydes undergo cross-aldol condensation with ketones in the presence of carbon-based solid acid under solvent-free conditions to afford the corresponding α,β-unsaturated aldol products in excellent yields. The catalyst is reusable several times without any decrease in the yield of the reactions.

  7. Dipolar correlations in structured solvents under nanoconfinement

    OpenAIRE

    Buyukdagli, Sahin; Blossey, Ralf

    2014-01-01

    We study electrostatic correlations in structured solvents confined to nanoscale systems. We derive variational equations of Netz-Orland type for a model liquid composed of finite size dipoles. These equations are solved for both dilute solvents and solvents at physiological concentrations in a slit nanopore geometry. Correlation effects are of major importance for the dielectric reduction and anisotropy of the solvent resulting from dipole image interactions and also lead to a reduction of v...

  8. Third generation capture system: precipitating amino acid solvent systems

    NARCIS (Netherlands)

    Sanchez Fernandez, E.; Misiak, K.; Ham, L. van der; Goetheer, E.L.V.

    2013-01-01

    This work summarises the results of the design of novel separation processes for CO2 removal from flue gas based on precipitating amino acid solvents. The processes here described (DECAB, DECAB Plus and pH-swing) use a combination of enhanced CO2 absorption (based on the Le Chatelier’s principle) an

  9. Weekly nanoparticle albumin bound-paclitaxel in combination with cisplatin versus weekly solvent-based paclitaxel plus cisplatin as first-line therapy in Chinese patients with advanced esophageal squamous cell carcinoma

    Directory of Open Access Journals (Sweden)

    Wang HY

    2016-09-01

    Full Text Available Hai-ying Wang, Zhi-hua Yao, Hong Tang, Yan Zhao, Xiao-san Zhang, Shu-na Yao, Shu-jun Yang, Yan-yan Liu Department of Internal Medicine, Affiliated Cancer Hospital of Zhengzhou University, Henan Cancer Hospital, Zhengzhou, Henan, People’s Republic of China Objective: More effective regimens for advanced esophageal squamous cell carcinoma (ESCC are urgently needed. Therefore, a retrospective study concerning the efficacy and safety of nanoparticle albumin-bound paclitaxel plus cisplatin (nab-TP versus solvent-based paclitaxel plus cisplatin (sb-TP as a first-line therapy was conducted in Chinese patients with advanced ESCC.Methods: From June 2009 to June 2015, 32 patients were treated with nab-paclitaxel (125 mg/m2 on the first and eighth days (30 minutes infusion and cisplatin (75 mg/m2 on the second day every 21 days (nab-TP arm. Also, 43 patients were treated with solvent-based paclitaxel (80 mg/m2 intravenously on the first and eighth days and the same dose of cisplatin (sb-TP arm. The two groups were compared in terms of objective response rate (ORR, disease control rate, progression-free survival (PFS, overall survival (OS, and safety profile. OS and PFS were estimated using Kaplan–Meier methods to determine associations between chemotherapy regimens and survival outcomes.Results: Nab-TP demonstrated a higher ORR (50% vs 30%; P=0.082 and disease control rate (81% vs 65%; P=0.124 than sb-TP. Median OS was similar for nab-TP and sb-TP (12.5 vs 10.7 months; P=0.269. However, nab-TP resulted in a longer median PFS (6.1 months [95% confidence interval: 5.3–6.9] than sb-TP (5.0 months [95% confidence interval: 4.4–5.6] (P=0.029. The most common adverse events included anemia, leukopenia, neutropenia, febrile neutropenia, and thrombocytopenia in both the groups and no statistically significant differences were observed between the groups. With statistically significant differences, significantly less grade ≥3 peripheral neuropathy

  10. Weekly nanoparticle albumin-bound paclitaxel in combination with cisplatin versus weekly solvent-based paclitaxel plus cisplatin as first-line therapy in Chinese patients with advanced esophageal squamous cell carcinoma

    Science.gov (United States)

    Wang, Hai-ying; Yao, Zhi-hua; Tang, Hong; Zhao, Yan; Zhang, Xiao-san; Yao, Shu-na; Yang, Shu-jun; Liu, Yan-yan

    2016-01-01

    Objective More effective regimens for advanced esophageal squamous cell carcinoma (ESCC) are urgently needed. Therefore, a retrospective study concerning the efficacy and safety of nanoparticle albumin-bound paclitaxel plus cisplatin (nab-TP) versus solvent-based paclitaxel plus cisplatin (sb-TP) as a first-line therapy was conducted in Chinese patients with advanced ESCC. Methods From June 2009 to June 2015, 32 patients were treated with nab-paclitaxel (125 mg/m2) on the first and eighth days (30 minutes infusion) and cisplatin (75 mg/m2) on the second day every 21 days (nab-TP arm). Also, 43 patients were treated with solvent-based paclitaxel (80 mg/m2) intravenously on the first and eighth days and the same dose of cisplatin (sb-TP arm). The two groups were compared in terms of objective response rate (ORR), disease control rate, progression-free survival (PFS), overall survival (OS), and safety profile. OS and PFS were estimated using Kaplan–Meier methods to determine associations between chemotherapy regimens and survival outcomes. Results Nab-TP demonstrated a higher ORR (50% vs 30%; P=0.082) and disease control rate (81% vs 65%; P=0.124) than sb-TP. Median OS was similar for nab-TP and sb-TP (12.5 vs 10.7 months; P=0.269). However, nab-TP resulted in a longer median PFS (6.1 months [95% confidence interval: 5.3–6.9]) than sb-TP (5.0 months [95% confidence interval: 4.4–5.6]) (P=0.029). The most common adverse events included anemia, leukopenia, neutropenia, febrile neutropenia, and thrombocytopenia in both the groups and no statistically significant differences were observed between the groups. With statistically significant differences, significantly less grade ≥3 peripheral neuropathy, arthralgia, and myalgia occurred in the nab-TP arm (all Pline therapy were similar between the two regimens. There were no treatment-related deaths in either group. Conclusion Nab-paclitaxel plus cisplatin is found to be an effective and tolerable option for advanced

  11. Solvent Extraction of Furfural From Biomass

    Science.gov (United States)

    Humphrey, M. F.

    1984-01-01

    Solvent-extraction method reduces energy required to remove furfural produced during acid hydrolysis of biomass. Acid hydrolysis performed in vessel containing both solvents and reacting ingredients. With intimate contact between solvents and aqueous hydrolyis liqour, furfural removed form liquor almost as fast as it forms.

  12. The hype with ionic liquids as solvents

    Science.gov (United States)

    Kunz, Werner; Häckl, Katharina

    2016-09-01

    In this mini review, we give our personal opinion about the present state of the art concerning Ionic Liquids, proposed as alternative solvents. In particular, we consider their different drawbacks and disadvantages and discuss the critical aspects of the research of Ionic Liquids as solvents. Finally, we point out some aspects on potentially promising Ionic Liquid solvents.

  13. The solvent component of macromolecular crystals

    Energy Technology Data Exchange (ETDEWEB)

    Weichenberger, Christian X. [European Academy of Bozen/Bolzano (EURAC), Viale Druso 1, Bozen/Bolzano, I-39100 Südtirol/Alto Adige (Italy); Afonine, Pavel V. [Lawrence Berkeley National Laboratory (LBNL), 1 Cyclotron Road, Mail Stop 64R0121, Berkeley, CA 94720 (United States); Kantardjieff, Katherine [California State University, San Marcos, CA 92078 (United States); Rupp, Bernhard, E-mail: br@hofkristallamt.org [k.-k. Hofkristallamt, 991 Audrey Place, Vista, CA 92084 (United States); Medical University of Innsbruck, Schöpfstrasse 41, A-6020 Innsbruck (Austria)

    2015-04-30

    On average, the mother liquor or solvent and its constituents occupy about 50% of a macromolecular crystal. Ordered as well as disordered solvent components need to be accurately accounted for in modelling and refinement, often with considerable complexity. The mother liquor from which a biomolecular crystal is grown will contain water, buffer molecules, native ligands and cofactors, crystallization precipitants and additives, various metal ions, and often small-molecule ligands or inhibitors. On average, about half the volume of a biomolecular crystal consists of this mother liquor, whose components form the disordered bulk solvent. Its scattering contributions can be exploited in initial phasing and must be included in crystal structure refinement as a bulk-solvent model. Concomitantly, distinct electron density originating from ordered solvent components must be correctly identified and represented as part of the atomic crystal structure model. Herein, are reviewed (i) probabilistic bulk-solvent content estimates, (ii) the use of bulk-solvent density modification in phase improvement, (iii) bulk-solvent models and refinement of bulk-solvent contributions and (iv) modelling and validation of ordered solvent constituents. A brief summary is provided of current tools for bulk-solvent analysis and refinement, as well as of modelling, refinement and analysis of ordered solvent components, including small-molecule ligands.

  14. Cation exchange-based post-processing of 68Ga-eluate: A comparison of three solvent systems for labelling of DOTATOC, NO2APBP and DATAm

    International Nuclear Information System (INIS)

    Interest in 68Ga has led to a number of innovations for its provision suitable for clinical application. Several post-processing methods are available to reduce eluate volume and remove metal trace impurities. In this work three cation exchange resin based post-processing methods (acetone, ethanol and NaCl) have been compared, using three model precursors (DOTATOC, NO2APBP and DATAm), in terms of labelling yield and reproducibility. The acetone and ethanol based methods provided greater reproducibility and yields that makes subsequent purification unnecessary. - Highlights: • Comparison of different 68Ga post-processing methods through the labelling of DOTATOC, NO2APBP and DATAm. • Comparison in terms of radiochemical yield, reproducibility and radiolysis. • Ethanol and acetone post-processed 68Ga facilitated the highest yields and reproducibility. • Ethanol post-processed 68Ga resulted in the lowest degree of radiolysis of 68Ga-DOTATOC. • Experimenting with different post-processing methods is an important optimisation step. • Ethanol-post processed 68Ga is suitable for clinical application

  15. Highly porous lithium-ion conducting solvent-free poly(vinylidene fluoride-co-hexafluoropropylene)/poly(ethyl methacrylate) based polymer blend electrolytes for Li battery applications

    International Nuclear Information System (INIS)

    Plasticised polymer blend electrolytes based on poly(vinylidenefluoride-co-hexafluoropropylene) (PVdF-co-HFP) and poly(ethyl methacrylate) (PEMA) were prepared for different lithium salts LiX (X = ClO4, CF3SO3, BF4 and N[CF3SO2]2) using facile solution casting. To confirm the structures and complexations of the electrolyte films, the prepared electrolytes were subjected to XRD and FTIR analysis. TG–DTA was used to ascertain the thermal stability of the electrolytes, and the porous nature of the electrolytes was identified using scanning electron microscopy via ion-hopping conduction. AC impedance analysis was performed for all the electrolyte samples at various temperatures from 303 to 363 K. The results suggest that among the various lithium salts, LiN[CF3SO2]2-based electrolytes exhibited the highest ionic conductivity (0.918 × 10−3 S cm−1). The temperature dependence of the ionic conductivity also complies with the VTF relation

  16. Reverse Schreinemakers Method for Experimental Analysis of Mixed-Solvent Electrolyte Systems

    DEFF Research Database (Denmark)

    Fosbøl, Philip Loldrup; Thomsen, Kaj; Stenby, Erling Halfdan

    2009-01-01

    A method based on Schreinemakers's tie-line theory of 1893 is derived for determining the composition and phase amounts in solubility experiments for multi-solvent electrolyte systems. The method uses the lever rule in reverse compared to Schreinemakers's wet residue method, and is therefore called...... the reverse Schreinemakers (RS) method. The method is based on simple mass balance principles similar to the wet residues method. It allows for accurate determination of the mixed-solvent phase composition even though part of the solvent may precipitate as complexes between solvent and salt. Discrepancies...

  17. Calculating the binding free energies of charged species based on explicit-solvent simulations employing lattice-sum methods: An accurate correction scheme for electrostatic finite-size effects

    Energy Technology Data Exchange (ETDEWEB)

    Rocklin, Gabriel J. [Department of Pharmaceutical Chemistry, University of California San Francisco, 1700 4th St., San Francisco, California 94143-2550, USA and Biophysics Graduate Program, University of California San Francisco, 1700 4th St., San Francisco, California 94143-2550 (United States); Mobley, David L. [Departments of Pharmaceutical Sciences and Chemistry, University of California Irvine, 147 Bison Modular, Building 515, Irvine, California 92697-0001, USA and Department of Chemistry, University of New Orleans, 2000 Lakeshore Drive, New Orleans, Louisiana 70148 (United States); Dill, Ken A. [Laufer Center for Physical and Quantitative Biology, 5252 Stony Brook University, Stony Brook, New York 11794-0001 (United States); Hünenberger, Philippe H., E-mail: phil@igc.phys.chem.ethz.ch [Laboratory of Physical Chemistry, Swiss Federal Institute of Technology, ETH, 8093 Zürich (Switzerland)

    2013-11-14

    The calculation of a protein-ligand binding free energy based on molecular dynamics (MD) simulations generally relies on a thermodynamic cycle in which the ligand is alchemically inserted into the system, both in the solvated protein and free in solution. The corresponding ligand-insertion free energies are typically calculated in nanoscale computational boxes simulated under periodic boundary conditions and considering electrostatic interactions defined by a periodic lattice-sum. This is distinct from the ideal bulk situation of a system of macroscopic size simulated under non-periodic boundary conditions with Coulombic electrostatic interactions. This discrepancy results in finite-size effects, which affect primarily the charging component of the insertion free energy, are dependent on the box size, and can be large when the ligand bears a net charge, especially if the protein is charged as well. This article investigates finite-size effects on calculated charging free energies using as a test case the binding of the ligand 2-amino-5-methylthiazole (net charge +1 e) to a mutant form of yeast cytochrome c peroxidase in water. Considering different charge isoforms of the protein (net charges −5, 0, +3, or +9 e), either in the absence or the presence of neutralizing counter-ions, and sizes of the cubic computational box (edges ranging from 7.42 to 11.02 nm), the potentially large magnitude of finite-size effects on the raw charging free energies (up to 17.1 kJ mol{sup −1}) is demonstrated. Two correction schemes are then proposed to eliminate these effects, a numerical and an analytical one. Both schemes are based on a continuum-electrostatics analysis and require performing Poisson-Boltzmann (PB) calculations on the protein-ligand system. While the numerical scheme requires PB calculations under both non-periodic and periodic boundary conditions, the latter at the box size considered in the MD simulations, the analytical scheme only requires three non

  18. Natural deep eutectic solvents: cytotoxic profile.

    Science.gov (United States)

    Hayyan, Maan; Mbous, Yves Paul; Looi, Chung Yeng; Wong, Won Fen; Hayyan, Adeeb; Salleh, Zulhaziman; Mohd-Ali, Ozair

    2016-01-01

    The purpose of this study was to investigate the cytotoxic profiles of different ternary natural deep eutectic solvents (NADESs) containing water. For this purpose, five different NADESs were prepared using choline chloride as a salt, alongside five hydrogen bond donors (HBD) namely glucose, fructose, sucrose, glycerol, and malonic acid. Water was added as a tertiary component during the eutectics preparation, except for the malonic acid-based mixture. Coincidentally, the latter was found to be more toxic than any of the water-based NADESs. A trend was observed between the cellular requirements of cancer cells, the viscosity of the NADESs, and their cytotoxicity. This study also highlights the first time application of the conductor-like screening model for real solvent (COSMO-RS) software for the analysis of the cytotoxic mechanism of NADESs. COSMO-RS simulation of the interactions between NADESs and cellular membranes' phospholipids suggested that NADESs strongly interacted with cell surfaces and that their accumulation and aggregation possibly defined their cytotoxicity. This reinforced the idea that careful selection of NADESs components is necessary, as it becomes evident that organic acids as HBD highly contribute to the increasing toxicity of these neoteric mixtures. Nevertheless, NADESs in general seem to possess relatively less acute toxicity profiles than their DESs parents. This opens the door for future large scale utilization of these mixtures. PMID:27386357

  19. Solvent transport through hard-soft segmented polymer nanocomposites.

    Science.gov (United States)

    Rath, Sangram K; Edatholath, Saji S; Patro, T Umasankar; Sudarshan, Kathi; Sastry, P U; Pujari, Pradeep K; Harikrishnan, G

    2016-01-28

    We conducted transport studies of a common solvent (toluene) in its condensed state, through a model hard-soft segmented polyurethane-clay nanocomposite. The solvent diffusivity is observed to be non-monotonic in a functional relationship with a filler volume fraction. In stark contrast, both classical tortuous path theory based geometric calculations and free volume measurements suggest the normally expected monotonic decrease in diffusivity with increase in clay volume fraction. Large deviations between experimentally observed diffusivity coefficients and those theoretically estimated from geometric theory are also observed. However, the equilibrium swelling of a nanocomposite as indicated by the solubility coefficient did not change. To gain an insight into the solvent interaction behavior, we conducted a pre- and post swollen segmented phase analysis of pure polymers and nanocomposites. We find that in a nanocomposite, the solvent has to interact with a filler altered hard-soft segmented morphology. In the altered phase separated morphology, the spatial distribution of thermodynamically segmented hard blocks in the continuous soft matrix becomes a strong function of filler concentration. Upon solvent interaction, this spatial distribution gets reoriented due to sorption and de-clustering. The results indicate strong non-barrier influences of nanoscale fillers dispersed in phase segmented block co-polymers, affecting solvent diffusivity through them. Based on pre- and post swollen morphological observations, we postulate a possible mechanism for the non-monotonic behaviour of solvent transport for hard-soft segmented co-polymers, in which the thermodynamic phase separation is influenced by the filler. PMID:26726752

  20. Elucidation of adsorption mechanisms of solvent molecules with distinct functional groups on amylose tris(3,5-dimethylphenylcarbamate)-based sorbent.

    Science.gov (United States)

    Wu, Shyuan-Guey; Lin, Ang-Yen; Hsieh, Han-Yu; Tsui, Hung-Wei

    2016-08-19

    Although polysaccharide derivative-based sorbents have been widely used for chiral separation, for a long time it remained unclear how these CSPs interact with the molecules associated with different functional groups. In this study, six molecules were chosen for retention behavior studies: acetone (AC), tetrahydrofuran (THF), methanol (MET), isopropanol (IPA), tert-butanol (TBA), and benzene (BZN). An immobilized amylose carbamate stationary phase, amylose tris(3,5-dimethylphenylcarbamate)-based sorbent, or Chiralpak IA, was used. Van't Hoff plots of ln k versus 1/T showed that alcohol molecules may simultaneously form two H-bonds with the IA sorbent. The results of density functional theory simulations and IR spectra support this inference showing that alcohol may bind with amide groups in three possible configurations. Frontal tests of AC and IPA were performed to estimate adsorbed solute concentration. Langmuir isotherm for IPA adsorption and mass action model for IPA self-aggregation were used for analyzing the IPA frontal results. Average IPA aggregation numbers range from 1.4 to 2.3. More than fifty percent of IPA molecules were found to be in aggregate form. From the frontal test results, thermodynamic properties of the adsorptions were determined. Retention behaviors of the five solutes as a function of IPA concentration were investigated. The absolute values B of the slopes from plots of the logarithms of the retention factor versus the logarithms of the IPA concentration increase in the order THF

  1. Elucidation of adsorption mechanisms of solvent molecules with distinct functional groups on amylose tris(3,5-dimethylphenylcarbamate)-based sorbent.

    Science.gov (United States)

    Wu, Shyuan-Guey; Lin, Ang-Yen; Hsieh, Han-Yu; Tsui, Hung-Wei

    2016-08-19

    Although polysaccharide derivative-based sorbents have been widely used for chiral separation, for a long time it remained unclear how these CSPs interact with the molecules associated with different functional groups. In this study, six molecules were chosen for retention behavior studies: acetone (AC), tetrahydrofuran (THF), methanol (MET), isopropanol (IPA), tert-butanol (TBA), and benzene (BZN). An immobilized amylose carbamate stationary phase, amylose tris(3,5-dimethylphenylcarbamate)-based sorbent, or Chiralpak IA, was used. Van't Hoff plots of ln k versus 1/T showed that alcohol molecules may simultaneously form two H-bonds with the IA sorbent. The results of density functional theory simulations and IR spectra support this inference showing that alcohol may bind with amide groups in three possible configurations. Frontal tests of AC and IPA were performed to estimate adsorbed solute concentration. Langmuir isotherm for IPA adsorption and mass action model for IPA self-aggregation were used for analyzing the IPA frontal results. Average IPA aggregation numbers range from 1.4 to 2.3. More than fifty percent of IPA molecules were found to be in aggregate form. From the frontal test results, thermodynamic properties of the adsorptions were determined. Retention behaviors of the five solutes as a function of IPA concentration were investigated. The absolute values B of the slopes from plots of the logarithms of the retention factor versus the logarithms of the IPA concentration increase in the order THF

  2. Sustainable efficient way for opioid peptide LVV-h7 preparation from enzymatic proteolysis in a microfluidic-based reaction-extraction process with solvent recycling.

    Science.gov (United States)

    Elagli, Adil; Belhacene, Kalim; Dhulster, Pascal; Froidevaux, Renato

    2016-05-01

    LVV-h7 (LVVYPWTQFR) is a bioactive peptide that can be obtained from blood as waste of food industry, more precisely from hemoglobin hydrolysis by pepsin. This opioid peptide belongs to the hemorphins family and have strong physiological effects that bring its use in pharmaceutics and various therapeutic treatments attractive, in particular for substituting its costly chemically synthetized analogous. Hemoglobin hydrolysis by pepsin generates a huge variety of peptides among whose LVV-h7 can be purified by liquid-liquid extraction (LLE). Herein, selective preparation of this peptide is proposed by a microfluidic-based continuous reaction-separation process. Hemoglobin hydrolysis in microreactor was firstly coupled to LVV-h7 LLE in octan-1-ol and then coupled to LVV-h7 back LLE in acidic water. This continuous process allowed to prepare pure LVV-h7, as confirmed by liquid chromatography and mass spectrometry. The microfluidic circuit also allowed octan-1-ol recycling in a closed loop, making this method more sustainable than similar biphasic batch process. PMID:26998857

  3. Synthesis, crystal structure and effect of deuterated solvents and temperature on visible and near infrared luminescence of N4-donor Schiff base lanthanide complexes

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Shuo; Fan, Rui-Qing; Gao, Song; Wang, Xinming; Yang, Yu-Lin, E-mail: ylyang@hit.edu.cn

    2014-05-01

    A series of lanthanide complexes [LnL(NO{sub 3}){sub 3}]·CH{sub 3}CN [Ln=Ce, (1• Ce); Nd, (2• Nd); Tb, (3• Tb); Dy, (4• Dy); Ho, (5• Ho); Er, (6• Er); Tm, (7• Tm); Yb (8• Yb)] have been synthesized by the reaction of N4 chelate ligand N,N'-bis(2-pyridinylmethylene)cyclohexane-1,2-diamine (L) with lanthanide salts. Photoluminescence spectra of complexes 2• Nd, 3• Tb, 4• Dy, and 8• Yb show the strong characteristic luminescence from visible to near infrared (NIR) region. Further, the singlet state (32,467 cm{sup −1}) and the lowest triplet (23,202 cm{sup −1}) energy level of L are calculated, indicating that the energy transfer from L to Tb{sup 3+} ion is more effective than that to Dy{sup 3+} ion. An extended work is developed to discuss on the effect of deuterated reagent and temperature on luminescent properties of 3• Tb and 8• Yb. - Highlights: • A series of N4-donor Schiff base lanthanide complex are designed and synthesized. • The characteristic luminescence from visible to near infrared region could be revealed. • The influence of deuterated reagent and temperature on luminescent properties is described.

  4. Modelling the surface free energy parameters of polyurethane coats-part 1. Solvent-based coats obtained from linear polyurethane elastomers.

    Science.gov (United States)

    Król, Piotr; Lechowicz, Jaromir B; Król, Bożena

    2013-04-01

    Polyurethane elastomers coating were synthesised by using typical diisocyanates, polyether and polyester polyols and HO-tertiary amines or diols as a chain extenders. Mole fractions of structural fragments (κ exp) responsible for the polar interactions within polyurethane chains were calculated by (1)H NMR method. Obtained results were confronted with the analogous parameter values (κ theor) calculated on the basis of process stoichiometry, considering the stage of the production of isocyanate prepolymers and reaction of their extension for polyurethanes. Trials of linear correlation between the κ exp parameters and surface free energy (SFE) values of investigated coatings were presented. SFE values were determined by Owens-Wendt method, using contact angles measured with the goniometric method. Based on achieved results, another empirical models, allowing for prediction the influence of the kind of polyurethane raw materials on SFE values of received coatings were determined. It was found that it is possible to regulate the SFE in the range millijoules per cubic metre by the selection of appropriate substrates. It has been found that use of 2,2,3,3-tetrafluoro-1,4-butanediol as a fluorinated extender of prepolymer chains is essential to obtain coatings with increased hydrophobicity, applied among others as biomaterials-next to diphenylmethane diisocyanate and polyoxyethylene glycol. PMID:23525512

  5. Alternatives to Organic Solvents in Industrial Cleaning Processes

    DEFF Research Database (Denmark)

    Jacobsen, Thomas

    1998-01-01

    industry, and vehicle repair and maintenance. There are, however, other elements that influence the possibility to substitute. The requirements to the resulting surface, depending on the following treatment of the surface. The character of the soilings to be removed. The possible presence of other...... cleaning agents in offset printing companies instead of volatile, toxic organic solvents. The present study is based on a project with the aim of defining other industrial processes, where organic solvents used for cleaning or degreasing can be replaced by non-volatile, low-toxic products, which are based...... on esters from fatty acids of vegetable origin (vegetable esters - VE).The study indicates that industrial cleaning/degreasing with organic solvents may be substituted with VEs on metal surfaces and on some coated surfaces, in manufacture of paints and inks, use of paints, use of inks (printing), metal...

  6. Insecticide solvents: interference with insecticidal action.

    Science.gov (United States)

    Brattsten, L B; Wilkinson, C F

    1977-06-10

    Several commercial solvent mixtures commonly used as insecticide carriers in spray formulations increase by more than threefold the microsomal N-demethylation of p-chloro N-methylaniline in midgut preparations of southern army-worm (Spodoptera eridania) larvae exposed orally to the test solvents. Under laboratory conditions, the same solvent mixtures exhibit a protective action against the in vivo toxicity of the insecticide carbaryl to the larvae. The data are discussed with respect to possible solvent-insecticide interactions occurring under field conditions and, more broadly, to potential toxicological hazards of these solvents to humans. PMID:860135

  7. Residual solvent determination by head space gas chromatography with flame ionization detector in omeprazole API

    OpenAIRE

    Saurabh Pandey; Preeti Pandey; Raj Kumar; Narendra Pal Singh

    2011-01-01

    Residual solvents in pharmaceutical samples are monitored using gas chromatography with head space. Based on good manufacturing practices, measuring residual solvents is mandatory for the release testing of all active pharmaceutical ingredients (API). The analysis of residual organic solvents (methanol, acetone, cyclohexane, dichloromethane, toluene) in Omeprazole, an active pharmaceutical ingredient was investigated. Omeprazole is a potent reversible inhibitor of the gastric proton pump H+/K...

  8. ELECTROCHEMICAL BEHAVIOUR OF METHYLENE BLUE IN NON-AQUEOUS SOLVENTS

    International Nuclear Information System (INIS)

    Graphical abstract: Display Omitted - Highlights: • The dye is electro-reduced in two separated monoelectronic charge transfers. • Solvent/supporting electrolyte/acid/base modifies the electrochemical parameters. • A dissociation equilibrium of the dye in non-aqueous solvent is proposed. • The electro-generated and stable dye-radical is also chemically produced in EDA or KOH/DMF. • A new species is reversibly formed in KOH/EtOH or ACN. - Abstract: The electrochemical behaviour of methylene blue in solution of non-aqueous solvents with different supporting electrolytes was studied by cyclic voltammetry. Dye electro-reduction presents two well-defined processes of monoelectronic charge transfer yielding a free radical in the first process and an anion in the second electron transfer. Free radical and anion are long living species in some of the studied media. Effects of supporting electrolyte and solvent on the peak potentials, the peak current functions and the reversibility of the charge transfer processes are reported. A dissociation equilibrium of the dye in solution of non-aqueous solvents and the acid or base added determine markedly the electrochemical responses. In the particular cases of KOH/DMF or EDA basic media the chemical formation of the stable methylene blue radical was detected and it was characterized by EPR spectroscopy. A general reaction scheme is proposed

  9. Renewable feedstocks in green solvents: thermodynamic study on phase diagrams of D-sorbitol and xylitol with dicyanamide based ionic liquids.

    Science.gov (United States)

    Paduszyński, Kamil; Okuniewski, Marcin; Domańska, Urszula

    2013-06-13

    Experimental and theoretical studies on thermodynamic properties of three ionic liquids based on dicyanamide anion (namely, 1-butyl-3-methylimidazolium dicyanamide, 1-butyl-1-methylpyrrolidinium dicyanamide, and 1-butyl-1-methylpiperidinium dicyanamide) and their binary mixtures with sugar alcohols (D-sorbitol and xylitol) were conducted in order to assess the applicability of the salts ionic liquids for dissolution of those biomass-related materials. Density and dynamic viscosity (at ambient pressure) of pure ionic liquids are reported in the temperature range from T = 293.15 to 363.15 K. Solid-liquid equilibrium phase diagrams in binary systems {sugar alcohol + ionic liquid} were measured with dynamic method up to the fusion temperature of sugar alcohol. The impact of the chemical structure of both the ionic liquid and sugar alcohol were established and discussed. For the very first time, the experimental solubility data were reproduced and analyzed in terms of equation of state rooted in statistical mechanics. For this purpose, perturbed-chain statistical associating fluid theory (PC-SAFT) was employed. In particular, new molecular schemes for the ionic liquids, D-sorbitol, and xylitol were proposed, and then the pure chemicals were parametrized by using available density and vapor pressure data. The model allowed accurate correlation of pure fluid properties for both ionic liquids and sugar alcohols, when the association term is taken into account. The results of solid-liquid equilibria modeling were also satisfactory. However, one or two adjustable binary corrections to the adopted combining rules were required to be adjusted in order to accurately capture the phase behavior. It was shown that a consistent thermodynamic description of extremely complex systems can be achieved by using relatively simple (but physically grounded) theoretical tools and molecular schemes.

  10. How membrane permeation is affected by donor delivery solvent.

    Science.gov (United States)

    Binks, Bernard P; Fletcher, Paul D I; Johnson, Andrew J; Elliott, Russell P

    2012-11-28

    We investigate theoretically and experimentally how the rate and extent of membrane permeation is affected by switching the donor delivery solvent from water to squalane for different permeants and membranes. In a model based on rate-limiting membrane diffusion, we derive explicit equations showing how the permeation extent and rate depend mainly on the membrane-donor and membrane-receiver partition coefficients of the permeant. Permeation results for systems containing all combinations of hydrophilic or hydrophobic donor solvents (aqueous solution or squalane), permeants (caffeine or testosterone) and polymer membranes (cellulose or polydimethylsiloxane) have been measured using a cell with stirred donor and re-circulating receiver compartments and continuous monitoring of the permeant concentration in the receiver phase. Relevant partition coefficients are also determined. Quantitative comparison of model and experimental results for the widely-differing permeation systems successfully enables the systematic elucidation of all possible donor solvent effects in membrane permeation. For the experimental conditions used here, most of the permeation systems are in agreement with the model, demonstrating that the model assumptions are valid. In these cases, the dominant donor solvent effects arise from changes in the relative affinities of the permeant for the donor and receiver solvents and the membrane and are quantitatively predicted using the separately measured partition coefficients. We also show how additional donor solvent effects can arise when switching the donor solvent causes one or more of the model assumptions to be invalid. These effects include a change in rate-limiting step, permeant solution non-ideality and others.

  11. Solvent viscosity dependence for enzymatic reactions

    CERN Document Server

    Sitnitsky, A E

    2008-01-01

    A mechanism for relationship of solvent viscosity with reaction rate constant at enzyme action is suggested. It is based on fluctuations of electric field in enzyme active site produced by thermally equilibrium rocking (cranckshaft motion) of the rigid plane (in which the dipole moment $\\approx 3.6 D$ lies) of a favourably located and oriented peptide group (or may be a few of them). Thus the rocking of the plane leads to fluctuations of the electric field of the dipole moment. These fluctuations can interact with the reaction coordinate because the latter in its turn has transition dipole moment due to separation of charges at movement of the reacting system along it. The rocking of the plane of the peptide group is sensitive to the microviscosity of its environment in protein interior and the latter is a function of the solvent viscosity. Thus we obtain an additional factor of interrelationship for these characteristics with the reaction rate constant. We argue that due to the properties of the cranckshaft ...

  12. Solvents in Organic Synthesis: Replacement and Multi-step Reaction Systems

    DEFF Research Database (Denmark)

    Gani, Rafiqul; Gómez, Paola Arenas; Folic, Milica;

    2008-01-01

    with the principles of green chemistry, highlight the need to minimize and optimize the use of organic solvents as much as possible. One important step in optimizing organic solvent use is the identification of suitable ‘greener' solvents that can help to minimize the environmental, health and safety concerns during...... design and commercial manufacture of chemical products. A method for selecting appropriate ‘greener' solvents for the promotion of a class of organic reactions has been previously developed by Gani et al. This method employs estimates of thermodynamic properties to generate a knowledge base of reaction...

  13. [Generic method for determination of volatile organic solvents in cosmetics].

    Science.gov (United States)

    Da, Jing; Huang, Xianglu; Wang, Gangli; Cao, Jin; Zhang, Qingsheng

    2014-11-01

    A generic screening, confirmation and determination method was established based on 36 commonly used volatile organic solvents in cosmetics by headspace gas chromatography- mass spectrometry (GC-MS). This method included a database for pilot screening and identifi- cation of those solvents and their quantitative method. Pilot screening database was composed by two sections, one was household section built by two columns with opposite polarities (col- umn VF-1301 ms and DB-5 ms) using retention index in different column systems as qualitative parameter, and the other was NIST MS search version 2.0. Meanwhile, the determination method of the 36 volatile solvents was developed with GC-MS. Cosmetic samples were dissolved in water and transferred to a headspace vial. After 30 min equilibration at 60 °C, the samples were analyzed by GC-MS equipped with a capillary chromatographic column VF-1301 ms. The external calibration was used for quantification. The limits of detection were from 0.01 to 3.3 μg/g, and the recoveries were from 60.77% to 126.6%. This study provided a generic method for pilot screening, identification, and quantitation of volatile organic solvents in cosmetics, and may solve the problem that different analytical methods need to be developed for different targeted compounds and pilot screening for potential candidate solvent residues.

  14. Green Solvents for Precision Cleaning

    Science.gov (United States)

    Grandelli, Heather; Maloney, Phillip; DeVor, Robert; Surma, Jan; Hintze, Paul

    2013-01-01

    Aerospace machinery used in liquid oxygen (LOX) fuel systems must be precision cleaned to achieve a very low level of non-volatile residue (solvent-replacement is non-flammable, environmentally benign, non-corrosive, inexpensive, effective and evaporates completely, leaving no residue. Highlighted is a green precision cleaning process, which is contaminant removal using supercritical carbon dioxide as the environmentally benign solvent. In this process, the contaminant is dissolved in carbon dioxide, and the parts are recovered at the end of the cleaning process completely dry and ready for use. Typical contaminants of aerospace components include hydrocarbon greases, hydraulic fluids, silicone fluids and greases, fluorocarbon fluids and greases and fingerprint oil. Metallic aerospace components range from small nuts and bolts to much larger parts, such as butterfly valves 18 in diameter. A fluorinated grease, Krytox, is investigated as a model contaminant in these preliminary studies, and aluminum coupons are employed as a model aerospace component. Preliminary studies are presented in which the experimental parameters are optimized for removal of Krytox from aluminum coupons in a stirred-batch process. The experimental conditions investigated are temperature, pressure, exposure time and impeller speed. Temperatures of 308 - 423 K, pressures in the range of 8.3 - 41.4 MPa, exposure times between 5 - 60 min and impeller speeds of 0 - 1000 rpm were investigated. Preliminary results showed up to 86 cleaning efficiency with the moderate processing conditions of 323 K, 13.8 MPa, 30 min and 750 rpm.

  15. Tuning the Morphology of Pharmaceutical Compounds via Model Based Solvent Selection%通过模型为基础的溶液选择来调控药品化合物的形貌

    Institute of Scientific and Technical Information of China (English)

    A.T.Karunanithi; C.Acquah; L.E.K.Achenie

    2008-01-01

    In this paper we present a strategy for tuning the crystal morphology of pharmaceutical compounds by the appropriate choice of solvent via an optimization model. A three-stage approach involving a pre-design stage, a product design stage and a post-design experimental verification stage is presented. The pre-design stage addresses the formulation of the property constraint for crystal morphology. This involves crystallization experiments and development of property models and constraints for morphology. In the design stage various property requirements for the solvent along with crystal morphology are considered and the product design problem is formulated as a mixed integer nonlinear programming model. The design stage provides an optimal solvent/list of candidate solvents. Similar to the pre-design stage, in the post design experimental verification stage, the morphology of the crystals (precipitated from the designed solvent) is verified through crystallization experiments followed by productcharacterization via scanning electron microscopy, powder X-ray diffraction imaging and Fourier transform spectra analysis.

  16. Development of novel contactor for nuclear solvent extraction

    International Nuclear Information System (INIS)

    For current designs of radiochemical plants, solvent-extraction contactors with no periodic maintenance like pulse column are the first choice. In addition, as costs of specialty solvents for nuclear extraction are quite high, there is a demand for operation at extreme phase ratios. Recently a novel mixer-settler was visualized and developed for this kind of service. The mixer of the novel contactor is based on rotated helical tubes and does not involve any mechanical moving part. Mass-transfer runs were carried out with aqueous nitric acid and 30% TBP solvent at A/O of 0.25-200 (in extraction) and A/O of 0.25-10 (in back-extraction mode). The developed contactor exhibited nearly 100% efficiency for all the cases. (authors)

  17. New Process for Preparation of Anisaldehyde Based on Ozonolysis of Anethole in Mixture Solvent System%水复合溶剂体系茴脑臭氧化反应合成茴香醛新工艺

    Institute of Scientific and Technical Information of China (English)

    于静; 哈成勇; 沈敏敏; 邓莲丽

    2012-01-01

    At room temperature, the anisaldehyde (4-methoxybenzaldehyde) was synthesized by the ozonolysis of anethole (1-methoxy-4-(1-propenyl)-benzene) in a novel and environmentally friendly mixture solvent system which was composed of organic solvent and water. The product was characterized by GC-MS, FT-IR and 1H-NMR spectra. The yields of anisaldehyde from organic solvent / water systems were compared with those from traditional solvent systems. The acetone / water solvent was chosen to be the optimal solvent system. Meanwhile, the effects of the solvent species, solvent quantity, O3 / O2 flow, water content in the mixture solvent and the reaction time on the reaction were investigated. By FT-IR and UV spectra, the reaction mechanism was investigated. It was found that, when O3 / O2 flow is 0.06 m3·h-1, the highest yield up to 82.70% can be obtained under the condition of using water / acetone as solvent system (water ratio in this solvent is 15%, m (anethole) / m (solvent) is 1 / 3), reaction time of 100 minutes and at room temperature. Compared with the traditional ozonolysis process, with the presence of water, ozonolysis of anethole results in the direct formation of anisaldehyde at room temperature and avoids the isolation or decomposition of ozonide. It is a convenient and environment friendly technology.%以茴脑为原料,有机溶剂与水复合溶剂为溶剂,室温下通过臭氧化分解反应制取茴香醛,并通过GC-MS、FT-IR和1H-NMR对产品进行了表征.对该溶剂体系与传统溶剂体系下茴香醛的产率进行了对比,并确定了丙酮/水体系为最佳溶剂体系.实验详细考察了溶剂用量、臭氧气流量、混合溶剂中水含量和反应时间等工艺参数.优化的工艺条件为:丙酮和水为溶剂,m(茴脑)∶m(混合溶剂)=1∶3,臭氧气流量0.06 m3·h-1,混合溶剂中水的质量含量为15%,反应时间100 min,茴香醛产率82.70%.该反应在水的存在下实现了室温下一步法合成茴香醛,避

  18. Solvent-free microwave extraction of bioactive compounds provides a tool for green analytical chemistry

    OpenAIRE

    Ying LI; Fabiano-Tixier, Anne-Sylvie; Vian, Maryline; Chemat, Farid

    2013-01-01

    We present an overview on solvent-free microwave-extraction techniques of bioactive compounds from natural products. This new technique is based on the concept of green analytical chemistry. It has proved to be an alternative to other techniques with the advantages of reducing extraction times, energy consumption, solvent use and CO2 emissions.

  19. Model development and process simulation of postcombustion carbon capture technology with aqueous AMP/PZ solvent

    NARCIS (Netherlands)

    van der Spek, Mijndert; Arendsen, Richard; Ramirez, Andrea; Faaij, André

    2016-01-01

    This study presents the development, application, and uncertainty analysis of a process simulation model for postcombustion CO2 capture with an AMP/PZ solvent blend based on state of the art knowledge on AMP/PZ solvent technology. The development includes the improvement of the physical property mod

  20. Remediation of Contaminated Soils by Solvent Flushing

    OpenAIRE

    Augustijn, Denie C.M.; Jessup, Ron E.; Rao, P. Suresh C.; Wood, A. Lynn

    1994-01-01

    Solvent flushing is a potential technique for remediating a waste disposal/spill site contaminated with organic chemicals. This technique involves the injection of a solvent mixture (e.g., water plus alcohols) that enhances contaminant solubility, reduces the retardation factor, and increases the release rates of the contaminants. A simulation model is developed to predict contaminant elution curves during solvent flushing for the case of one‐dimensional, steady flow through a contaminated me...

  1. Modeling of salt solubilities in mixed solvents

    OpenAIRE

    Chiavone Filho O.; Rasmussen P.

    2000-01-01

    A method to correlate and predict salt solubilities in mixed solvents using a UNIQUAC+Debye-Hückel model is developed. The UNIQUAC equation is applied in a form with temperature-dependent parameters. The Debye-Hückel model is extended to mixed solvents by properly evaluating the dielectric constants and the liquid densities of the solvent media. To normalize the activity coefficients, the symmetric convention is adopted. Thermochemical properties of the salt are used to estimate the solubilit...

  2. Bio-refinery of orange peels waste: A new concept based on integrated green and solvent free extraction processes using ultrasound and microwave techniques to obtain essential oil, polyphenols and pectin

    OpenAIRE

    Boukroufa, Meryem; Petigny, Loic; Rakotomanomana, Njara

    2015-01-01

    In this study, extraction of essential oil, polyphenols and pectin from orange peel has been optimized using microwave and ultrasound technology without adding any solvent but only ‘‘in situ’’ water which was recycled and used as solvent. The essential oil extraction performed by Microwave Hydrodiffusion and Gravity (MHG) was optimized and compared to steam distillation extraction (SD). No significant changes in yield were noticed: 4.22 ± 0.03% and 4.16 ± 0.05% for MHG and SD, respectively. A...

  3. OCCUPATIONAL SOLVENT EXPOSURE ASSOCIATED WITH DEVELOPMENTAL TOXICITY

    Directory of Open Access Journals (Sweden)

    Alina-Costina LUCA

    2016-05-01

    Full Text Available Organic solvent is a broad term that applies to many classes of chemicals. The solvent (benzene, toluene etc. aspects of occupational exposure are reviewed via the examination of the use, occurrence, and disposition as well as population’s potential of risk. The general public can be exposed to solvent in ambient air as a result of its occurrence in paint process. Solvents are primarily irritants to the skin and mucous membranes and have narcotic properties at high concentrations. Published epidemiological data identified various types of birth defects in certain occupations.

  4. Extractive Distillation with Salt in Solvent

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Extractive distillation with salt in solvent is a new process for producing anhydrous ethanol by combining the principle of "salt effect" and some traditional extractive distillation methods. Compared with the common extractive distillation the performance of solvent is improved, the recycling amount of solvent is reduced to 1/4-1/5, and the number of theoretical plates is reduced to 1/3. Energy consumption and cost of equipment are also reduced and continuous production is realized. High efficiency and low solvent wastage make this technique feasible.

  5. Modeling of salt solubilities in mixed solvents

    Directory of Open Access Journals (Sweden)

    O. Chiavone Filho

    2000-06-01

    Full Text Available A method to correlate and predict salt solubilities in mixed solvents using a UNIQUAC+Debye-Hückel model is developed. The UNIQUAC equation is applied in a form with temperature-dependent parameters. The Debye-Hückel model is extended to mixed solvents by properly evaluating the dielectric constants and the liquid densities of the solvent media. To normalize the activity coefficients, the symmetric convention is adopted. Thermochemical properties of the salt are used to estimate the solubility product. It is shown that the proposed procedure can describe with good accuracy a series of salt solubility measurements in aqueous organic solvent mixtures.

  6. Interactions between polyacrylonitrile and solvents: density functional theory study and two-dimensional infrared correlation analysis.

    Science.gov (United States)

    Wu, Qing-Yun; Chen, Xiao-Na; Wan, Ling-Shu; Xu, Zhi-Kang

    2012-07-19

    Polyacrylonitrile (PAN) is a semicrystalline polymer with high polarity and is usually processed from solutions. Selected solvents for processing influence both the structure and properties of PAN products. We describe the interactions between PAN and various solvents by theoretical calculation based on density functional theories (DFT), and by experimental methods of Fourier transform infrared (FTIR) spectra and two-dimensional infrared (2D-IR) correlation analysis. The selected solvents include dimethyl sulfone (DMSO2), dimethyl sulfoxide (DMSO), ethylene carbonate (EC), propylene carbonate (PC), N,N-dimethyl formamide (DMF), and N,N-dimethyl acetamide (DMAc). Calculation results show that the PAN model monomer (PAN') interacts with each solvent through dipole-dipole interaction and formed PAN'-solvent complexes. Each complex displays an antiparallel alignment of interacting pair between the C≡N group of PAN' and the polar group of solvent molecule (S═O or C═O group). The calculated binding energies (ΔE) reveal that PAN' preferentially interacts with solvent in the order of DMSO2 > DMSO > EC > PC > DMF > DMAc. Red shifts of vibration frequencies are observed for C≡N, S═O, and C═O stretching bands. The C≡N stretching band shifts from 2245 cm(-1) in PAN to 2240, 2242, and 2241 cm(-1) in PAN-DMSO, PAN-EC, and PAN-DMF mixtures, respectively, indicating the existence of PAN-solvent interactions. Moreover, 2D-IR correlation analysis shows that as the PAN content increases, DMSO molecules vary prior to PAN-DMSO complexes, and change earlier than PAN bulk. However, PAN-EC and PAN-DMF mixtures follow the order of PAN bulk > PAN-solvent complexes > solvent molecules. This combination of theoretical simulation and experimental characterization is useful in selection of solvents for PAN or even other polar polymers and can provide an insight into the physical behavior of PAN-solvent complexes. PMID:22702536

  7. Issues Related to Cleaning Complex Geometry Surfaces with ODC-Free Solvents

    Science.gov (United States)

    Bradford, Blake F.; Wurth, Laura A.; Nayate, Pramod D.; McCool, Alex (Technical Monitor)

    2001-01-01

    Implementing ozone depleting chemicals (ODC)-free solvents into full-scale reusable solid rocket motor cleaning operations has presented problems due to the low vapor pressures of the solvents. Because of slow evaporation, solvent retention is a problem on porous substrates or on surfaces with irregular geometry, such as threaded boltholes, leak check ports, and nozzle backfill joints. The new solvents are being evaluated to replace 1,1,1-trichloroethane, which readily evaporates from these surfaces. Selection of the solvents to be evaluated on full-scale hardware was made based on results of subscale tests performed with flat surface coupons, which did not manifest the problem. Test efforts have been undertaken to address concerns with the slow-evaporating solvents. These concerns include effects on materials due to long-term exposure to solvent, potential migration from bolthole threads to seal surfaces, and effects on bolt loading due to solvent retention in threads. Tests performed to date have verified that retained solvent does not affect materials or hardware performance. Process modifications have also been developed to assist drying, and these can be implemented if additional drying becomes necessary.

  8. Quantification of residual solvents in antibody drug conjugates using gas chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Medley, Colin D., E-mail: medley.colin@gene.com [Genentech Inc., Small Molecule Pharmaceutical Sciences, 1 DNA Way, South San Francisco, CA 94080 (United States); Kay, Jacob [Research Pharmaceutical Services, 520 Virginia Dr. Fort, Washington, PA (United States); Li, Yi; Gruenhagen, Jason; Yehl, Peter; Chetwyn, Nik P. [Genentech Inc., Small Molecule Pharmaceutical Sciences, 1 DNA Way, South San Francisco, CA 94080 (United States)

    2014-11-19

    Highlights: • Sensitive residual solvents detection in ADCs. • 125 ppm QL for common conjugation solvents. • Generic and validatable method. - Abstract: The detection and quantification of residual solvents present in clinical and commercial pharmaceutical products is necessary from both patient safety and regulatory perspectives. Head-space gas chromatography is routinely used for quantitation of residual solvents for small molecule APIs produced through synthetic processes; however residual solvent analysis is generally not needed for protein based pharmaceuticals produced through cultured cell lines where solvents are not introduced. In contrast, antibody drug conjugates and other protein conjugates where a drug or other molecule is covalently bound to a protein typically use solvents such as N,N-dimethylacetamide (DMA), N,N‑dimethylformamide (DMF), dimethyl sulfoxide (DMSO), or propylene glycol (PG) to dissolve the hydrophobic small molecule drug for conjugation to the protein. The levels of the solvent remaining following the conjugation step are therefore important to patient safety as these parental drug products are introduced directly into the patients bloodstream. We have developed a rapid sample preparation followed by a gas chromatography separation for the detection and quantification of several solvents typically used in these conjugation reactions. This generic method has been validated and can be easily implemented for use in quality control testing for clinical or commercial bioconjugated products.

  9. Quantification of residual solvents in antibody drug conjugates using gas chromatography

    International Nuclear Information System (INIS)

    Highlights: • Sensitive residual solvents detection in ADCs. • 125 ppm QL for common conjugation solvents. • Generic and validatable method. - Abstract: The detection and quantification of residual solvents present in clinical and commercial pharmaceutical products is necessary from both patient safety and regulatory perspectives. Head-space gas chromatography is routinely used for quantitation of residual solvents for small molecule APIs produced through synthetic processes; however residual solvent analysis is generally not needed for protein based pharmaceuticals produced through cultured cell lines where solvents are not introduced. In contrast, antibody drug conjugates and other protein conjugates where a drug or other molecule is covalently bound to a protein typically use solvents such as N,N-dimethylacetamide (DMA), N,N‑dimethylformamide (DMF), dimethyl sulfoxide (DMSO), or propylene glycol (PG) to dissolve the hydrophobic small molecule drug for conjugation to the protein. The levels of the solvent remaining following the conjugation step are therefore important to patient safety as these parental drug products are introduced directly into the patients bloodstream. We have developed a rapid sample preparation followed by a gas chromatography separation for the detection and quantification of several solvents typically used in these conjugation reactions. This generic method has been validated and can be easily implemented for use in quality control testing for clinical or commercial bioconjugated products

  10. Single polymer chains in poor solvent: using the bond fluctuation method with explicit solvent.

    Science.gov (United States)

    Jentzsch, Christoph; Werner, Marco; Sommer, Jens-Uwe

    2013-03-01

    We use the bond fluctuation model with explicit solvent to study single polymer chains under poor solvent conditions. Static and dynamic properties of the bond fluctuation model with explicit solvent are compared with the implicit solvent model, and the Θ-temperatures are determined for both solvent models. We show that even in the very poor solvent regime, dynamics is not frozen for the explicit solvent model. We investigate some aspects of the structure of a single collapsed globule and show that rather large chain lengths are necessary to reach the scaling regime of a dense sphere. The force-extension curve of a single polymer chain under poor solvent conditions in the fixed end-to-end distance ensemble is analyzed. We find that the transition of the tadpole conformation to the stretched chain conformation is rather smooth because of fluctuation effects, which is in agreement with recent experimental results. PMID:23485321

  11. REMEDIATION OF CONTAMINATED SOILS BY SOLVENT FLUSHING

    Science.gov (United States)

    Solvent flushing is a potential technique for remediating a waste disposal/spill site contaminated with organic chemicals. This technique involves the injection of a solvent mixture (e.g., water plus alcohols) that enhances contaminant solubility, reduces the retardation factor, ...

  12. REMEDIATING PESTICIDE CONTAMINATED SOILS USING SOLVENT EXTRACTION

    Science.gov (United States)

    Bench-scale solvent extraction studies were performed on soil samples obtained from a Superfund site contaminated with high levels of p,p'-DDT, p,p'-DDD,, p,p'-DDE and toxaphene. The effectiveness of the solvent extraction process was assessed using methanol and 2-propanol as sol...

  13. Modeling of Salt Solubilities in Mixed Solvents

    DEFF Research Database (Denmark)

    Chiavone-Filho, O.; Rasmussen, Peter

    2000-01-01

    A method to correlate and predict salt solubilities in mixed solvents using a UNIQUAC+Debye-Huckel model is developed. The UNIQUAC equation is applied in a form with temperature-dependent parameters. The Debye-Huckel model is extended to mixed solvents by properly evaluating the dielectric consta...

  14. Structuring of polymer solutions upon solvent evaporation

    NARCIS (Netherlands)

    Schaefer, C.; van der Schoot, P.; Michels, J. J.

    2015-01-01

    The morphology of solution-cast, phase-separated polymers becomes finer with increasing solvent evaporation rate. We address this observation theoretically for a model polymer where demixing is induced by steady solvent evaporation. In contrast to what is the case for a classical, thermal quench inv

  15. Improved Supercritical-Solvent Extraction of Coal

    Science.gov (United States)

    Compton, L.

    1982-01-01

    Raw coal upgraded by supercritical-solvent extraction system that uses two materials instead of one. System achieved extraction yields of 20 to 49 weight percent. Single-solvent yields are about 25 weight percent. Experimental results show extraction yields may be timedependent. Observed decreases in weight of coal agreed well with increases in ash content of residue.

  16. Supercritical-Multiple-Solvent Extraction From Coal

    Science.gov (United States)

    Corcoran, W.; Fong, W.; Pichaichanarong, P.; Chan, P.; Lawson, D.

    1983-01-01

    Large and small molecules dissolve different constituents. Experimental apparatus used to test supercritical extraction of hydrogen rich compounds from coal in various organic solvents. In decreasing order of importance, relevant process parameters were found to be temperature, solvent type, pressure, and residence time.

  17. SCENARIOS EVALUATION TOOL FOR CHLORINATED SOLVENT MNA

    Energy Technology Data Exchange (ETDEWEB)

    Vangelas, K; Brian02 Looney, B; Michael J. Truex; Charles J. Newell

    2006-08-16

    Over the past three decades, much progress has been made in the remediation of chlorinated solvents from the subsurface. Yet these pervasive contaminants continue to present a significant challenge to the U.S. Department of Energy (DOE), other federal agencies, and other public and private organizations. The physical and chemical properties of chlorinated solvents make it difficult to rapidly reach the low concentrations typically set as regulatory limits. These technical challenges often result in high costs and long remediation time frames. In 2003, the DOE through the Office of Environmental Management funded a science-based technical project that uses the U.S. Environmental Protection Agency's technical protocol (EPA, 1998) and directives (EPA, 1999) on Monitored Natural Attenuation (MNA) as the foundation on which to introduce supporting concepts and new scientific developments that will support remediation of chlorinated solvents based on natural attenuation processes. This project supports the direction in which many site owners want to move to complete the remediation of their site(s), that being to complete the active treatment portion of the remedial effort and transition into MNA. The overarching objective of the effort was to examine environmental remedies that are based on natural processes--remedies such as Monitored Natural Attenuation (MNA) or Enhanced Attenuation (EA). The research program did identify several specific opportunities for advances based on: (1) mass balance as the central framework for attenuation based remedies, (2) scientific advancements and achievements during the past ten years, (3) regulatory and policy development and real-world experience using MNA, and (4) exploration of various ideas for integrating attenuation remedies into a systematic set of ''combined remedies'' for contaminated sites. These opportunities are summarized herein and are addressed in more detail in referenced project documents and

  18. On the Road to Biopolymer Aerogels—Dealing with the Solvent

    Directory of Open Access Journals (Sweden)

    Raman Subrahmanyam

    2015-12-01

    Full Text Available Aerogels are three-dimensional ultra-light porous structures whose characteristics make them exciting candidates for research, development and commercialization leading to a broad scope of applications ranging from insulation and catalysis to regenerative medicine and pharmaceuticals. Biopolymers have recently entered the aerogel foray. In order to fully realize their potential, progressive strategies dealing with production times and costs reduction must be put in place to facilitate the scale up of aerogel production from lab to commercial scale. The necessity of studying solvent/matrix interactions during solvent exchange and supercritical CO2 drying is presented in this study using calcium alginate as a model system. Four frameworks, namely (a solvent selection methodology based on solvent/polymer interaction; (b concentration gradient influence during solvent exchange; (c solvent exchange kinetics based on pseudo second order model; and (d minimum solvent concentration requirements for supercritical CO2 drying, are suggested that could help assess the role of the solvent in biopolymer aerogel production.

  19. Organic solvent regeneration of granular activated carbon

    Science.gov (United States)

    Cross, W. H.; Suidan, M. T.; Roller, M. A.; Kim, B. R.; Gould, J. P.

    1982-09-01

    The use of activated carbon for the treatment of industrial waste-streams was shown to be an effective treatment. The high costs associated with the replacement or thermal regeneration of the carbon have prohibited the economic feasibility of this process. The in situ solvent regeneration of activated carbon by means of organic solvent extraction was suggested as an economically alternative to thermal regeneration. The important aspects of the solvent regeneration process include: the physical and chemical characteristics of the adsorbent, the pore size distribution and energy of adsorption associated with the activated carbon; the degree of solubility of the adsorbate in the organic solvent; the miscibility of the organic solvent in water; and the temperature at which the generation is performed.

  20. Variational Optimization of an All-Atom Implicit Solvent Force Field to Match Explicit Solvent Simulation Data.

    Science.gov (United States)

    Bottaro, Sandro; Lindorff-Larsen, Kresten; Best, Robert B

    2013-12-10

    The development of accurate implicit solvation models with low computational cost is essential for addressing many large-scale biophysical problems. Here, we present an efficient solvation term based on a Gaussian solvent-exclusion model (EEF1) for simulations of proteins in aqueous environment, with the primary aim of having a good overlap with explicit solvent simulations, particularly for unfolded and disordered states - as would be needed for multiscale applications. In order to achieve this, we have used a recently proposed coarse-graining procedure based on minimization of an entropy-related objective function to train the model to reproduce the equilibrium distribution obtained from explicit water simulations. Via this methodology, we have optimized both a charge screening parameter and a backbone torsion term against explicit solvent simulations of an α-helical and a β-stranded peptide. The performance of the resulting effective energy function, termed EEF1-SB, is tested with respect to the properties of folded proteins, the folding of small peptides or fast-folding proteins, and NMR data for intrinsically disordered proteins. The results show that EEF1-SB provides a reasonable description of a wide range of systems, but its key advantage over other methods tested is that it captures very well the structure and dimension of disordered or weakly structured peptides. EEF1-SB is thus a computationally inexpensive (~ 10 times faster than Generalized-Born methods) and transferable approximation for treating solvent effects. PMID:24748852

  1. The chemistry of nonaqueous solvents v.4 solution phenomena and aprotic solvents

    CERN Document Server

    Lagowski, J J

    1976-01-01

    The Chemistry of Nonaqueous Solvents, Volume IV: Solution Phenomena and Aprotic Solvents focuses on the chemistry of nonaqueous solvents, with emphasis on solution phenomena and aprotic solvents such as tetramethylurea, inorganic acid chlorides, cyclic carbonates, and sulfolane. This book is organized into seven chapters and begins with an overview of the theory of electrical conductivity and elementary experimental considerations, along with some of the interesting research on nonaqueous solvents. It then turns to a discussion on hydrogen bonding phenomena in nonaqueous systems as probed

  2. PARIS II: Computer Aided Solvent Design for Pollution Prevention

    Science.gov (United States)

    This product is a summary of U.S. EPA researchers' work developing the solvent substitution software tool PARIS II (Program for Assisting the Replacement of Industrial Solvents, version 2.0). PARIS II finds less toxic solvents or solvent mixtures to replace more toxic solvents co...

  3. Predicting the Solubility of Pharmaceutical Cocrystals in Solvent/Anti-Solvent Mixtures.

    Science.gov (United States)

    Lange, Linda; Heisel, Stefan; Sadowski, Gabriele

    2016-01-01

    In this work, the solubilities of pharmaceutical cocrystals in solvent/anti-solvent systems were predicted using PC-SAFT in order to increase the efficiency of cocrystal formation processes. Modeling results and experimental data were compared for the cocrystal system nicotinamide/succinic acid (2:1) in the solvent/anti-solvent mixtures ethanol/water, ethanol/acetonitrile and ethanol/ethyl acetate at 298.15 K and in the ethanol/ethyl acetate mixture also at 310.15 K. The solubility of the investigated cocrystal slightly increased when adding small amounts of anti-solvent to the solvent, but drastically decreased for high anti-solvent amounts. Furthermore, the solubilities of nicotinamide, succinic acid and the cocrystal in the considered solvent/anti-solvent mixtures showed strong deviations from ideal-solution behavior. However, by accounting for the thermodynamic non-ideality of the components, PC-SAFT is able to predict the solubilities in all above-mentioned solvent/anti-solvent systems in good agreement with the experimental data. PMID:27164075

  4. Predicting the Solubility of Pharmaceutical Cocrystals in Solvent/Anti-Solvent Mixtures

    Directory of Open Access Journals (Sweden)

    Linda Lange

    2016-05-01

    Full Text Available In this work, the solubilities of pharmaceutical cocrystals in solvent/anti-solvent systems were predicted using PC-SAFT in order to increase the efficiency of cocrystal formation processes. Modeling results and experimental data were compared for the cocrystal system nicotinamide/succinic acid (2:1 in the solvent/anti-solvent mixtures ethanol/water, ethanol/acetonitrile and ethanol/ethyl acetate at 298.15 K and in the ethanol/ethyl acetate mixture also at 310.15 K. The solubility of the investigated cocrystal slightly increased when adding small amounts of anti-solvent to the solvent, but drastically decreased for high anti-solvent amounts. Furthermore, the solubilities of nicotinamide, succinic acid and the cocrystal in the considered solvent/anti-solvent mixtures showed strong deviations from ideal-solution behavior. However, by accounting for the thermodynamic non-ideality of the components, PC-SAFT is able to predict the solubilities in all above-mentioned solvent/anti-solvent systems in good agreement with the experimental data.

  5. Solvents and Parkinson disease: A systematic review of toxicological and epidemiological evidence

    Energy Technology Data Exchange (ETDEWEB)

    Lock, Edward A., E-mail: e.lock@ljmu.ac.uk [Liverpool John Moores University, School of Pharmacy and Biomolecular Sciences, Byrom Street, Liverpool (United Kingdom); Zhang, Jing [University of Washington, Department of Pathology, School of Medicine, Seattle, WA (United States); Checkoway, Harvey [University of Washington, Department of Environmental and Occupational Health Sciences, Seattle, WA (United States)

    2013-02-01

    Parkinson disease (PD) is a debilitating neurodegenerative motor disorder, with its motor symptoms largely attributable to loss of dopaminergic neurons in the substantia nigra. The causes of PD remain poorly understood, although environmental toxicants may play etiologic roles. Solvents are widespread neurotoxicants present in the workplace and ambient environment. Case reports of parkinsonism, including PD, have been associated with exposures to various solvents, most notably trichloroethylene (TCE). Animal toxicology studies have been conducted on various organic solvents, with some, including TCE, demonstrating potential for inducing nigral system damage. However, a confirmed animal model of solvent-induced PD has not been developed. Numerous epidemiologic studies have investigated potential links between solvents and PD, yielding mostly null or weak associations. An exception is a recent study of twins indicating possible etiologic relations with TCE and other chlorinated solvents, although findings were based on small numbers, and dose–response gradients were not observed. At present, there is no consistent evidence from either the toxicological or epidemiologic perspective that any specific solvent or class of solvents is a cause of PD. Future toxicological research that addresses mechanisms of nigral damage from TCE and its metabolites, with exposure routes and doses relevant to human exposures, is recommended. Improvements in epidemiologic research, especially with regard to quantitative characterization of long-term exposures to specific solvents, are needed to advance scientific knowledge on this topic. -- Highlights: ► The potential for organic solvents to cause Parkinson's disease has been reviewed. ► Twins study suggests etiologic relations with chlorinated solvents and Parkinson's. ► Animal studies with TCE showed potential to cause damage to dopaminergic neurons. ► Need to determine if effects in animals are relevant to human

  6. 基于乙酸为溶剂和催化剂的芳乙酮Mannich反应%Mannich Reaction of Aromatic Ketones Based on Acetic Acid as Solvent and Catalyst

    Institute of Scientific and Technical Information of China (English)

    卜辉娟; 张静; 穆博帅; 李媛

    2014-01-01

    Mannich reaction is one of the most important methods for preparation ofβ-amino ketones and alde-hydes and α,β-unsaturated carbonyl compounds, as well as one of the most important basic reaction types in organic chemistry and it is widely applied as a key step in the synthesis of numerous pharmaceuticals and natu-ral products. However, during the synthesis of 1-aryl acrylic ketone 2 by the Mannich reaction of aromatic ke-tones, formaldehyde and secondary amine using acetic acid as solvent and catalyst, the Mannich base and ex-pectedα,β-unsaturated ketones 2 were not obtained and another kind of compounds 3 , 2-aryl formyl allyl ace-tate were obtained in moderate to good yields(65%-73%) . The structure of compounds 3 was confirmed by 1 H NMR, 13 C NMR, HRMS and IR spectra. The reasons of producing compounds 3 were studied and the re-sults suggested that the special structure of aromatic ketones and excess acetic acid in reaction are responsible for the exceptional Mannich reaction. In addition, the reaction mechanism was postulated.%采用乙酸作溶剂和催化剂,将芳乙酮与甲醛和二级胺进行Mannich反应及热解反应,并未得到预期的Mannich碱或α,β-不饱和酮(2),而是以较高产率(65%~73%)生成了乙酸(2-芳甲酰基)烯丙酯(3a~3o)。通过核磁共振波谱、高分辨质谱和红外光谱表征了化合物3a~3o的结构,研究了此“异常”反应的发生条件,并提出了可能的反应机理。结果表明,芳乙酮的特殊结构及反应中过量的乙酸是产生化合物3a~3o的决定因素。

  7. 溶剂型涂料中16种有害物质的气相色谱-质谱同时检测方法%Determination of 16 Harmful Substances in Solvent Based Coatings by GC -MS Method

    Institute of Scientific and Technical Information of China (English)

    薛希妹; 薛秋红; 刘心同; 单宝田; 牛增元

    2011-01-01

    A GC - MS method was developed for the determination of 16 kinds of harmful substances (e. g. methanol, volatile halohydrocarbons, benzene homologues, the free toluene diisocyanate and hexane diisocyanate)in solvent based coatings. The extraction and separation efficiencies of targeted compounds by using organic solutions of ethyl acetate, n-hexane, tetrahydrofuran and acetonitrile were investigated. The procedure of sample pre-treatment and the conditions of instruments were optimized. The quantitative analysis of compounds were carried out by using 2-bromopropane and 1, 2,4-trichlorobenzene as the internal standard, and acetonitrile as extraction reagent. The result indicated that the calibration curves of the 16 harmful substances were linear in the range of 5 -200 mg/L with correlation coefficients no less than 0. 999. The spiked recoveries ranged from 80% to 105%with relative standard deviations less than 5.0%. The detection limits ranged from 0. 08 mg/L to 1.41 mg/L. The method was rapid, sensitive and accurate.%建立了溶剂型涂料中16种有害物质(甲醇、卤代烃、苯系物和游离二异氰酸酯)的GC-MS同时检测方法,研究了乙酸乙酯、正己烷、四氢呋喃和乙腈对各有害物质的提取和分离效果,并对样品前处理和色谱条件进行了优化.样品中加入2-溴丙烷和1,2,4-三氯苯作内标,用乙腈超声萃取并经有机膜过滤后,用.GC-MS进行测定,内标法定量.结果表明:16种有害物质在5~200mg/L范围内线性关系良好,相关系数均不低于0.999;样品的加标回收率为80%~105%,相对标准偏差小于5.0%,检出限为0.08~1.41 mg/L.

  8. Computer-aided tool for solvent selection in pharmaceutical processes: Solvent swap

    DEFF Research Database (Denmark)

    Papadakis, Emmanouil; K. Tula, Anjan; Gernaey, Krist V.;

    swap solvents is developed and is used to retrieve information for the most commonly used solvent candidates typically found in the pharmaceutical industry. The selection is verified by simulation. The framework for the solvent selection and solvent swap is part of an integrated computer......-aided framework with the objective to assist the pharmaceutical industry in gaining better process understanding. A software interface to improve the usability of the tool has been created also.......In the pharmaceutical processes, solvents have a multipurpose role since different solvents can be used in different stages (such as chemical reactions, separations and purification) in the multistage active pharmaceutical ingredients (APIs) production process. The solvent swap and selection tasks...

  9. Permeability of commercial solvents through living human skin

    DEFF Research Database (Denmark)

    Ursin, C; Hansen, C M; Van Dyk, J W;

    1995-01-01

    was characterized by calculation of the "percent error of the slope." The following permeability rates (g/m2h) of single solvents were measured: dimethyl sulfoxide (DMSO), 176; N-methyl-2-pyrrolidone, 171; dimethyl acetamide, 107; methyl ethyl ketone, 53; methylene chloride, 24; [3H]water, 14.8; ethanol, 11.......3; butyl acetate, 1.6; gamma-butyrolactone, 1.1; toluene, 0.8; propylene carbonate, 0.7; and sulfolane, 0.2. The effect of [3H]water saturation on the shape of the presteady state portion of the permeation curve was determined and found to be very dependent on the solvent. The permeability of mixtures...... of DMSO and octyl acetate were measured. No octyl acetate was detected and the permeability of DMSO was proportional to its mole fraction in the mixture. The effect of two hours of solvent exposure on the viability of skin (based on DNA synthesis) was measured and found to be very dependent on the solvent....

  10. Solvent effects on photophysical properties of copper and zinc porphyrins

    Institute of Scientific and Technical Information of China (English)

    LI Ye

    2008-01-01

    The photophysics of Zn(tetraphenylporphyrin,TPP), Zn(tetra-2,4,6-trimethylphenyl porphyrin, TMP), Zn (tetra-(o-dichlorophenyl) porphyrin, TPPCI8), Cu(tetraphenylporphyrin,TPP), Cu(tetra-2,4,6-trimethyl-phenyl porphyrin,TMP), and Cu(tetra-(o-dichlorophenyl) porphyrin, TPPCI8,TPPCI8) in several solvents have been investigated on steady state and time-resolved spectroscopy. The Cu(TPPCI8) is normal and shows no evidence of CT transition in the visible or near UV regions in nonpolar solvent. However,Cu(TPPCI8)shows a blue shift in the absorption spectrum and intramolecular CT bands at absorption spectra in polar solvent, which shows a fluorescence maximum emission at 650 nm and 8.4 ns lifetime.The reason can be attributed to two points. Firstly, the increase of solvent polarity can enlarge outer reorganisational energy, which is favorable to reduce the activation free energy of charger-transfer transition based on Marcus theory of electron transfer. Moreover, the internal heavy-atom effect on Cu(TPPCI8) is encouraging to stabilize the 2T1 state also, which increases the possibility of population to CT band from 2T1 state. This result is in accord with an earlier estimate of a 10 ns lifetime and CT absorption at 640 nm bands for the CT state of Cu (Ⅱ) octethylporphyrins. Other possible reasons arousing unusual fluorescence like H-bonding, axial ligands, molecular aggregation are excluded.

  11. Preparation of Candesartan and Atorvastatin Nanoparticles by Solvent Evaporation

    Directory of Open Access Journals (Sweden)

    Josef Jampilek

    2012-11-01

    Full Text Available The solubility, absorption and distribution of a drug are involved in the basic aspects of oral bioavailability Solubility is an essential characteristic and influences the efficiency of the drug. Over the last ten years, the number of poorly soluble drugs has steadily increased. One of the progressive ways for increasing oral bioavaibility is the technique of nanoparticle preparation, which allows many drugs to thus reach the intended site of action. Candesartan cilexetil and atorvastatin, belonging to class II of the biopharmaceutical classification system, were chosen as model active pharmaceutical ingredients in this study. Forty samples were prepared either by antisolvent precipitation/solvent evaporation method or by the emulsion/solvent evaporation technique with various commonly used surface-active excipients as nanoparticle stabilizers. All samples were analyzed by means of dynamic light scattering. The particle size of the determined 36 nanoparticle samples was to 574 nm, whereas 32 samples contained nanoparticles of less than 200 nm. Relationships between solvents and excipients used and their amount are discussed. Based on the results the investigated solvent evaporation methods can be used as an effective and an affordable technique for the preparation of nanoparticles.

  12. Sequentially solution-processed, nanostructured polymer photovoltaics using selective solvents

    KAUST Repository

    Kim, Do Hwan

    2014-01-01

    We demonstrate high-performance sequentially solution-processed organic photovoltaics (OPVs) with a power conversion efficiency (PCE) of 5% for blend films using a donor polymer based on the isoindigo-bithiophene repeat unit (PII2T-C10C8) and a fullerene derivative [6,6]-phenyl-C[71]-butyric acid methyl ester (PC71BM). This has been accomplished by systematically controlling the swelling and intermixing processes of the layer with various processing solvents during deposition of the fullerene. We find that among the solvents used for fullerene deposition that primarily swell but do not re-dissolve the polymer underlayer, there were significant microstructural differences between chloro and o-dichlorobenzene solvents (CB and ODCB, respectively). Specifically, we show that the polymer crystallite orientation distribution in films where ODCB was used to cast the fullerene is broad. This indicates that out-of-plane charge transport through a tortuous transport network is relatively efficient due to a large density of inter-grain connections. In contrast, using CB results in primarily edge-on oriented polymer crystallites, which leads to diminished out-of-plane charge transport. We correlate these microstructural differences with photocurrent measurements, which clearly show that casting the fullerene out of ODCB leads to significantly enhanced power conversion efficiencies. Thus, we believe that tuning the processing solvents used to cast the electron acceptor in sequentially-processed devices is a viable way to controllably tune the blend film microstructure. © 2014 The Royal Society of Chemistry.

  13. Water-enhanced solubility of carboxylic acids in organic solvents and its applications to extraction processes

    Energy Technology Data Exchange (ETDEWEB)

    Starr, J.N.; King, C.J.

    1991-11-01

    The solubilities of carboxylic acids in certain organic solvents increase remarkably with an increasing amount of water in the organic phase. This phenomenon leads to a novel extract regeneration process in which the co-extracted water is selectively removed from an extract, and the carboxylic acid precipitates. This approach is potentially advantageous compared to other regeneration processes because it removes a minor component of the extract in order to achieve a large recovery of acid from the extract. Carboxylic acids of interest include adipic acid, fumaric acid, and succinic acid because of their low to moderate solubilities in organic solvents. Solvents were screened for an increase in acid solubility with increased water concentration in the organic phase. Most Lewis-base solvents were found to exhibit this increased solubility phenomena. Solvents that have a carbonyl functional group showed a very large increase in acid solubility. 71 refs., 52 figs., 38 tabs.

  14. Thin-film composite crosslinked polythiosemicarbazide membranes for organic solvent nanofiltration (OSN)

    KAUST Repository

    Aburabie, Jamaliah

    2015-01-01

    In this work we report a new class of solvent stable thin-film composite (TFC) membrane fabricated on crosslinked polythiosemicarbazide (PTSC) as substrate that exhibits superior stability compared with other solvent stable polymeric membranes reported up to now. Integrally skinned asymmetric PTSC membranes were prepared by the phase inversion process and crosslinked with an aromatic bifunctional crosslinker to improve the solvent stability. TFC membranes were obtained via interfacial polymerization using trimesoyl chloride (TMC) and diaminopiperazine (DAP) monomers. The membranes were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and contact angle measurement.The membranes exhibited high fluxes toward solvents like tetrahydrofuran (THF), dimethylformamide (DMF) and dimethylsulfoxide (DMSO) ranging around 20L/m2 h at 5bar with a molecular weight cut off (MWCO) of around 1000g/mol. The PTSC-based thin-film composite membranes are very stable toward polar aprotic solvents and they have potential applications in the petrochemical and pharmaceutical industry.

  15. Environmental Impacts on Nuclear Reprocessing Solvents

    Science.gov (United States)

    Gillens, A. R.; Fessenden, J. E.

    2009-12-01

    Nuclear tests have been employed ever since the first nuclear explosion in Alamogordo, NM during the mid-1940s. Nuclear weapons pose a threat to civil society and result in extensive biological (medical) damages. For this reason, treaties banning nuclear tests and weapons have been employed since the 1960s to cease proliferation of weapons. However, as nuclear tests continue in secrecy and actinides, such as plutonium and uranium, are eligible for theft, nuclear forensics is needed to prevent weapons proliferation. In this study, solvents [tributyl phosphate (TBP), dodecane, decanol] used in reprocessing spent nuclear fuel are analyzed using an isotope ratio mass spectrometer, which provides indisputable evidence in identifying the operation in which solvents were used. Solvent samples are observed under variable conditions in the laboratory for different time periods. It is assumed that their carbon isotope values (δ13C) will become more positive (shift heavy) with time. It is found that the solvents are hygroscopic. TBP leaves the most robust signature compared to the other solvents studied and the isotope values for all solvents under all conditions become more positive with time. This study serves as primary research in understanding how solvents behave under variable conditions in the laboratory and how this could be translated to the environment in fate and transport studies.

  16. Organic Solvent Tolerant Lipases and Applications

    Directory of Open Access Journals (Sweden)

    Shivika Sharma

    2014-01-01

    Full Text Available Lipases are a group of enzymes naturally endowed with the property of performing reactions in aqueous as well as organic solvents. The esterification reactions using lipase(s could be performed in water-restricted organic media as organic solvent(s not only improve(s the solubility of substrate and reactant in reaction mixture but also permit(s the reaction in the reverse direction, and often it is easy to recover the product in organic phase in two-phase equilibrium systems. The use of organic solvent tolerant lipase in organic media has exhibited many advantages: increased activity and stability, regiospecificity and stereoselectivity, higher solubility of substrate, ease of products recovery, and ability to shift the reaction equilibrium toward synthetic direction. Therefore the search for organic solvent tolerant enzymes has been an extensive area of research. A variety of fatty acid esters are now being produced commercially using immobilized lipase in nonaqueous solvents. This review describes the organic tolerance and industrial application of lipases. The main emphasis is to study the nature of organic solvent tolerant lipases. Also, the potential industrial applications that make lipases the biocatalysts of choice for the present and future have been presented.

  17. A smooth and differentiable bulk-solvent model for macromolecular diffraction

    International Nuclear Information System (INIS)

    A new method for modeling the bulk solvent in macromolecular diffraction data based on Babinet’s principle is presented. The proposed models offer the advantage of differentiability with respect to atomic coordinates. Inclusion of low-resolution data in macromolecular crystallography requires a model for the bulk solvent. Previous methods have used a binary mask to accomplish this, which has proven to be very effective, but the mask is discontinuous at the solute–solvent boundary (i.e. the mask value jumps from zero to one) and is not differentiable with respect to atomic parameters. Here, two algorithms are introduced for computing bulk-solvent models using either a polynomial switch or a smoothly thresholded product of Gaussians, and both models are shown to be efficient and differentiable with respect to atomic coordinates. These alternative bulk-solvent models offer algorithmic improvements, while showing similar agreement of the model with the observed amplitudes relative to the binary model as monitored using R, Rfree and differences between experimental and model phases. As with the standard solvent models, the alternative models improve the agreement primarily with lower resolution (>6 Å) data versus no bulk solvent. The models are easily implemented into crystallographic software packages and can be used as a general method for bulk-solvent correction in macromolecular crystallography

  18. Fast molecular beacon hybridization in organic solvents with improved target specificity.

    Science.gov (United States)

    Dave, Neeshma; Liu, Juewen

    2010-12-01

    DNA hybridization is of tremendous importance in biology, bionanotechnology, and biophysics. Molecular beacons are engineered DNA hairpins with a fluorophore and a quencher labeled on each of the two ends. A target DNA can open the hairpin to give an increased fluorescence signal. To date, the majority of molecular beacon detections have been performed only in aqueous buffers. We describe herein DNA detection in nine different organic solvents, methanol, ethanol, isopropanol, acetonitrile, formamide, dimethylformamide (DMF), dimethyl sulfoxide (DMSO), ethylene glycol, and glycerol, varying each up to 75% (v/v). In comparison with detection in water, the detection in organic solvents showed several important features. First, the molecular beacon hybridizes to its target DNA in the presence of all nine solvents up to a certain percentage. Second, the rate of this hybridization was significantly faster in most organic solvents compared with water. For example, in 56% ethanol, the beacon showed a 70-fold rate enhancement. Third, the ability of the molecular beacon to discriminate single-base mismatch is still maintained. Lastly, the DNA melting temperature in the organic solvents showed a solvent concentration-dependent decrease. This study suggests that molecular beacons can be used for applications where organic solvents must be involved or organic solvents can be intentionally added to improve the molecular beacon performance.

  19. A NOVEL HYDROPHILIC POLYMER MEMBRANE FOR THE DEHYDRATION OF ORGANIC SOLVENTS

    Science.gov (United States)

    Novel hydrophilic polymer membranes based on polyallylamine ydrochloride- polyvinylalcohol are developed. The high selectivity and flux characteristics of these membranes for the dehydration of organic solvents are evaluated using pervaporation technology and are found to be ver...

  20. TRUEX process solvent cleanup with solid sorbents

    Energy Technology Data Exchange (ETDEWEB)

    Tse, Pui-Kwan; Reichley-Yinger, L.; Vandegrift, G.F.

    1989-01-01

    Solid sorbents, alumina, silica gel, and Amberlyst A-26 have been tested for the cleanup of degraded TRUEX-NPH solvent. A sodium carbonate scrub alone does not completely remove acidic degradation products from highly degraded solvent and cannot restore the stripping performance of the solvent. By following the carbonate scrub with either neutral alumina or Amberlyst A-26 anion exchange resin, the performance of the TRUEX-NPH is substantially restored. The degraded TRUEX-NPH was characterized before and after treatment by supercritical fluid chromatography. Its performance was evaluated by americium distribution ratios, phase-separation times, and lauric acid distribution coefficients. 17 refs., 2 figs., 5 tabs.

  1. Genomic and Genetic Approaches to Solvent Tolerance

    Energy Technology Data Exchange (ETDEWEB)

    Eleftherios T. Papoutsakis

    2005-06-10

    The proposed research is to understand and exploit the molecular basis that determines tolerance of the industrially important anaerobic clostridia to solvents. Furthermore, we aim to develop general genomic and metabolic engineering strategies for understanding the molecular basis of tolerance to chemicals and for developing tolerant strains. Our hypothesis is that the molecular basis of what makes bacterial cells able to withstand high solvent concentrations can be used to metabolically engineer cells so that they can tolerate higher concentrations of solvents and related chemicals.

  2. Solvent Handbook Database System user's manual

    International Nuclear Information System (INIS)

    Industrial solvents and cleaners are used in maintenance facilities to remove wax, grease, oil, carbon, machining fluids, solder fluxes, mold release, and various other contaminants from parts, and to prepare the surface of various metals. However, because of growing environmental and worker-safety concerns, government regulations have already excluded the use of some chemicals and have restricted the use of halogenated hydrocarbons because they affect the ozone layer and may cause cancer. The Solvent Handbook Database System lets you view information on solvents and cleaners, including test results on cleaning performance, air emissions, recycling and recovery, corrosion, and non-metals compatibility. Company and product safety information is also available

  3. Study on the regeneration of waste lubricating oil based on solvent refining with sulfolance%环丁砜溶剂精制再生废润滑油的研究

    Institute of Scientific and Technical Information of China (English)

    吴亮; 刘莹; 孙彦祥; 杨藏军; 宋宇翔; 陈文艺

    2015-01-01

    Sulfolance was used as solvent to regenerate waste lubricating oil. The influence of refining tem-perature,refining time and solvent to oil volume ratio of waste oil refining effect was investigated. The re-sult showed that the optimal condition of sulfolance refining:the solvent to oil volume ratio of 1. 4,the re-fine temperature of 120 ℃,the refine time of 30 min. Under this process condition,the yield of the recov-ered oil was 85. 89% ,the viscosity index was 103. 62. Meanwhile,in the time of 30 min constant refining, studied refining temperature,solvent to oil volume ratio on recycled oil viscosity index and linear regres-sion using SPSS software,derived regenerative refined oil viscosity index and refining temperature,solvent to oil volume ratio the regression equation.%以环丁砜为溶剂进行再生废润滑油的研究。考察了精制温度、精制时间及剂油体积比对废润滑油精制效果的影响。结果表明,环丁砜精制的最佳工艺条件为:剂油体积比为1.4,精制温度120℃,精制时间为30 min。在该工艺条件下,再生精制油收率达到85.89%,再生油的黏度指数达103.62。同时,在精制时间为30 min 恒定时,研究了精制温度、剂油体积比对再生油黏度指数的影响,并采用 SPSS 软件进行线性回归,得出了再生油黏度指数与精制温度、剂油体积比的回归方程。

  4. Review of recent ORNL studies in solvent cleanup and diluent degradation. Consolidated Fuel-Reprocessing Program

    Energy Technology Data Exchange (ETDEWEB)

    Mailen, J.C.; Tallent, O.K.

    1982-01-01

    Testing of solvent cleanup methods to replace the use of sodium carbonate in the Purex process has been ongoing for several years in order to reduce the quantity of waste sodium nitrate generated and to improve phase separation. Alternate solvent cleanup methods include the use of packed columns of base-treated silica gel or solvent scrubbing with hydrazine oxalate. Degradation of the diluent was shown to generate long-chain organic acids which appear to be the major culprits in the phase separation problems encountered in sodium carbonate scrubbers. Solvent scrubbing with hydrazine oxalate gives improved phase separations. Solvent cleanup in columns packed with base-treated silica gel avoids the phase separation problem since a dispersable aqueous phase is not present. Removals of TBP degradation products and metal-ion complexes by sodium carbonate, hydrazine salts, or by packed beds of base-treated silica gel are all satisfactory. Solvent scrubbing by hydrazine oxalate solutions is the prime candidate for solvent cleanup in fuel reprocessing plants.

  5. Interdependence of conformational and chemical reaction dynamics during ion assembly in polar solvents.

    Science.gov (United States)

    Ji, Minbiao; Hartsock, Robert W; Sun, Zheng; Gaffney, Kelly J

    2011-10-01

    We have utilized time-resolved vibrational spectroscopy to study the interdependence of the conformational and chemical reaction dynamics of ion assembly in solution. We investigated the chemical interconversion dynamics of the LiNCS ion pair and the (LiNCS)(2) ion-pair dimer, as well as the spectral diffusion dynamics of these ionic assemblies. For the strongly coordinating Lewis base solvents benzonitrile, dimethyl carbonate, and ethyl acetate, we observe Li(+) coordination by both solvent molecules and NCS(-) anions, while the weak Lewis base solvent nitromethane shows no evidence for solvent coordination of Li(+) ions. The strong interaction between the ion-pair dimer structure and the Lewis base solvents leads to ion-pair dimer solvation dynamics that proceed more slowly than the ion-pair dimer dissociation. We have attributed the slow spectral diffusion dynamics to electrostatic reorganization of the solvent molecules coordinated to the Li(+) cations present in the ion-pair dimer structure and concluded that the dissociation of ion-pair dimers depends more critically on longer length scale electrostatic reorganization. This unusual inversion of the conformational and chemical reaction rates does not occur for ion-pair dimer dissociation in nitromethane or for ion pair association in any of the solvents.

  6. First title: Ionic liquids-useful reaction green solvents for the future Second title: ionic liquids are the replacements for environmentally damaging solvents in a wide range of chemical processes.

    OpenAIRE

    K.Vijaya Bhaskar

    2012-01-01

    Ionic liquids (IL) represent fascinating new class of solvents with unusual physical and chemical properties; low melting salts (up to 1000C). The main driving force for research in this area is the need to find replacement for environmentally damaging solvents in a wide range of chemical processes. To date, most chemical reactions have been carried out in molecular solvents. For the past twenty years, most of our understanding of our chemistry has been based upon the behavior of molecules in...

  7. Prediction of the solubility in lipidic solvent mixture: Investigation of the modeling approach and thermodynamic analysis of solubility.

    Science.gov (United States)

    Patel, Shruti V; Patel, Sarsvatkumar

    2015-09-18

    Self-micro emulsifying drug delivery system (SMEDDS) is one of the methods to improve solubility and bioavailability of poorly soluble drug(s). The knowledge of the solubility of pharmaceuticals in pure lipidic solvents and solvent mixtures is crucial for designing the SMEDDS of poorly soluble drug substances. Since, experiments are very time consuming, a model, which allows for solubility predictions in solvent mixtures based on less experimental data is desirable for efficiency. Solvents employed were Labrafil® M1944CS and Labrasol® as lipidic solvents; Capryol-90®, Capryol-PGMC® and Tween®-80 as surfactants; Transcutol® and PEG-400 as co-solvents. Solubilities of both drugs were determined in single solvent systems at temperature (T) range of 283-333K. In present study, we investigated the applicability of the thermodynamic model to understand the solubility behavior of drugs in the lipiodic solvents. By using the Van't Hoff and general solubility theory, the thermodynamic functions like Gibbs free energy, enthalpy and entropy of solution, mixing and solvation for drug in single and mixed solvents were understood. The thermodynamic parameters were understood in the framework of drug-solvent interaction based on their chemical similarity and dissimilarity. Clotrimazole and Fluconazole were used as active ingredients whose solubility was measured in single solvent as a function of temperature and the data obtained were used to derive mathematical models which can predict solubility in multi-component solvent mixtures. Model dependent parameters for each drug were calculated at each temperature. The experimental solubility data of solute in mixed solvent system were measured experimentally and further correlated with the calculates values obtained from exponent model and log-linear model of Yalkowsky. The good correlation was observed between experimental solubility and predicted solubility. PMID:26092370

  8. Organic fragments from graphene oxide: Isolation, characterization and solvent effects

    Indian Academy of Sciences (India)

    Ravula Thirupathi; Y Jayasubba Reddy; Erode N Prabhakaran; Hanudatta S Atreya

    2014-05-01

    As-prepared graphene oxide (GO) contains oxidative debris which can be washed using basic solutions. We present the isolation and characterization of these debris. Dynamic light scattering (DLS) is used to monitor the separation of the debris in various solvents in the presence of different protic and aprotic alkylamino bases. The study reveals that the debris are rich in carbonyl functional groups and water is an essential component for separation and removal of the debris from GO under oxidative reaction conditions.

  9. Full scale solvent extraction remedial results

    International Nuclear Information System (INIS)

    Sevenson Extraction Technology, Inc. has completed the development of the Soil Restoration Unit (initially developed by Terra-Kleen Corporation), a mobile, totally enclosed solvent extraction treatment facility for the removal of organic contaminated media is greater by a closed loop, counter current process that recycles all solvents. The solvents used are selected for the individual site dependant upon the contaminants, such as PCB's, oil, etc. and the soil conditions. A mixture of up to fourteen non-toxic solvents can be used for complicated sites. The full scale unit has been used to treat one superfund site, the Traband Site in Tulsa, Oklahoma, and is currently treating another superfund site, the Pinette's Salvage Yard Site in Washburn, Maine. The full scale Soil Restoration Unit has also been used at a non-superfund site, as part of a TSCA Research and Development permit. The results from these sites will be discussed in brief herein, and in more detail in the full paper

  10. Solvent-Free Synthesis of New Coumarins

    Directory of Open Access Journals (Sweden)

    Redah I. Al-Bayati

    2012-01-01

    Full Text Available A solvent-free synthesis of five series of coumarin derivatives using microwave assistant is presented herein. The synthesized compounds are fully characterized by UV-VIS, FT-IR, and NMR spectroscopy.

  11. Computer-Aided Solvent Screening for Biocatalysis

    DEFF Research Database (Denmark)

    Abildskov, Jens; Leeuwen, M.B. van; Boeriu, C.G.;

    2013-01-01

    constrained properties related to chemical reaction equilibrium, substrate and product solubility, water solubility, boiling points, toxicity and others. Two examples are provided, covering the screening of solvents for lipase-catalyzed transesterification of octanol and inulin with vinyl laurate...

  12. Implicit solvent methods for free energy estimation.

    Science.gov (United States)

    Decherchi, Sergio; Masetti, Matteo; Vyalov, Ivan; Rocchia, Walter

    2015-02-16

    Solvation is a fundamental contribution in many biological processes and especially in molecular binding. Its estimation can be performed by means of several computational approaches. The aim of this review is to give an overview of existing theories and methods to estimate solvent effects giving a specific focus on the category of implicit solvent models and their use in Molecular Dynamics. In many of these models, the solvent is considered as a continuum homogenous medium, while the solute can be represented at the atomic detail and at different levels of theory. Despite their degree of approximation, implicit methods are still widely employed due to their trade-off between accuracy and efficiency. Their derivation is rooted in the statistical mechanics and integral equations disciplines, some of the related details being provided here. Finally, methods that combine implicit solvent models and molecular dynamics simulation, are briefly described. PMID:25193298

  13. Predicting the Activity Coefficients of Free-Solvent for Concentrated Globular Protein Solutions Using Independently Determined Physical Parameters

    OpenAIRE

    McBride, Devin W; Rodgers, Victor G. J.

    2013-01-01

    The activity coefficient is largely considered an empirical parameter that was traditionally introduced to correct the non-ideality observed in thermodynamic systems such as osmotic pressure. Here, the activity coefficient of free-solvent is related to physically realistic parameters and a mathematical expression is developed to directly predict the activity coefficients of free-solvent, for aqueous protein solutions up to near-saturation concentrations. The model is based on the free-solvent...

  14. Method of stripping metals from organic solvents

    Science.gov (United States)

    Todd, Terry A.; Law, Jack D.; Herbst, R. Scott; Romanovskiy, Valeriy N.; Smirnov, Igor V.; Babain, Vasily A.; Esimantovski, Vyatcheslav M.

    2009-02-24

    A new method to strip metals from organic solvents in a manner that allows for the recycle of the stripping agent. The method utilizes carbonate solutions of organic amines with complexants, in low concentrations, to strip metals from organic solvents. The method allows for the distillation and reuse of organic amines. The concentrated metal/complexant fraction from distillation is more amenable to immobilization than solutions resulting from current practice.

  15. Hydrogen recovery by novel solvent systems

    Energy Technology Data Exchange (ETDEWEB)

    Shinnar, R.; Ludmer, Z.; Ullmann, A.

    1991-08-01

    The objective of this work is to develop a novel method for purification of hydrogen from coal-derived synthesis gas. The study involved a search for suitable mixtures of solvents for their ability to separate hydrogen from the coal derived gas stream in significant concentration near their critical point of miscibility. The properties of solvent pairs identified were investigated in more detail to provide data necessary for economic evaluation and process development.

  16. Solvent management in a reprocessing plant

    International Nuclear Information System (INIS)

    Solvent management in large capacity reprocessing plant is studied to limit production of organic wastes. Chemical processing increases life time of solvent. Low pressure distillation allows the recycling of TBP and diluent at a low activity level. Besides heavy degradation products are eliminated. For the safety the flash point of distillated diluent increases slightly. Tests on an industrial scale started in 1985 and since more than 500 cubic meters were treated

  17. Solvent Hold Tank Sample Results For MCU-15-710-711-712: June 2015 Monthly Sample

    Energy Technology Data Exchange (ETDEWEB)

    Fondeur, F. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Taylor-Pashow, K. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-10-07

    Savannah River National Laboratory (SRNL) received one set of Solvent Hold Tank (SHT) samples (MCU-15-710, MCU-15-711, and MCU-15-712), pulled on 06/15/2015 for analysis. The samples were combined and analyzed for composition. Analysis of the composite sample MCU-15-710-711-712 indicated a low concentration (~ 55 % of nominal) of the suppressor (TiDG) and concentrations of the extractant (MaxCalix), and of the modifier (Cs-7SB) in the solvent that were slightly lower than nominal. This analysis confirms the addition of TiDG, MaxCalix, and modifier (92 % of nominal) to the solvent in February 2015. Based on the current monthly sample, the levels of TiDG, MaxCalix, and modifier were sufficient when this solvent sample was collected from MCU. A higher cesium concentration (9.3 E6 dpm/mL) was observed in this sample relative to recent samples. In the past, this level of cesium appeared to correlate with upsets in the MCU operation. It is not known at this time the reason for the higher cesium level in this solvent. No impurities above the 1000 ppm level were found in this solvent by the Semi-Volatile Organic Analysis (SVOA). In addition, the sample contains up to 10.4 micrograms of mercury per gram of solvent (or 8.7 µg/mL). A relatively large cesium concentration (9.3 E 6 dpm/mL) was measured in this solvent and it may indicate poor cesium stripping. The laboratory will continue to monitor the quality of the solvent in particular for any new impurities or degradation of the solvent components.

  18. Hazardous Solvent Substitution Data System reference manual

    International Nuclear Information System (INIS)

    Concern for the environment, in addition to Federal regulation, mandate the replacement of hazardous solvents with safer cleaning agents. Manufacturers are working to produce these replacement solvents. As these products are developed, potential users need to be informed of their availability. To promote the use of these new products instead of traditional solvents, the Idaho National Engineering Laboratory (INEL) has developed the Hazardous Solvent Substitution Data System (HSSDS). The HSSDS provides a comprehensive system of information on alternatives to hazardous solvents and related subjects, and it makes that information available to solvent users, industrial hygienists, and process engineers. The HSSDS uses TOPIC reg-sign, a text retrieval system produced by Verity, Inc., to allow a user to search for information on a particular subject. TOPIC reg-sign produces a listing of the retrieved documents and allows the use to examine the documents individually and to use the information contained in them. This reference manual does not replace the comprehensive TOPIC reg-sign user documentation (available from Verity, Inc.), or the HSSDS Tutorial (available from the INEL). The purpose of this reference manual is to provide enough instruction on TOPIC reg-sign so the user may begin accessing the data contained in the HSSDS

  19. Solvent dependent photophysical properties of dimethoxy curcumin

    Science.gov (United States)

    Barik, Atanu; Indira Priyadarsini, K.

    2013-03-01

    Dimethoxy curcumin (DMC) is a methylated derivative of curcumin. In order to know the effect of ring substitution on photophysical properties of curcumin, steady state absorption and fluorescence spectra of DMC were recorded in organic solvents with different polarity and compared with those of curcumin. The absorption and fluorescence spectra of DMC, like curcumin, are strongly dependent on solvent polarity and the maxima of DMC showed red shift with increase in solvent polarity function (Δf), but the above effect is prominently observed in case of fluorescence maxima. From the dependence of Stokes' shift on solvent polarity function the difference between the excited state and ground state dipole moment was estimated as 4.9 D. Fluorescence quantum yield (ϕf) and fluorescence lifetime (τf) of DMC were also measured in different solvents at room temperature. The results indicated that with increasing solvent polarity, ϕf increased linearly, which has been accounted for the decrease in non-radiative rate by intersystem crossing (ISC) processes.

  20. Recycling of solvent used in a solvent extraction of petroleum hydrocarbons contaminated soil.

    OpenAIRE

    Wu, Guozhong; Li, XinGang; Coulon, Frederic; LI Hong; Lian, Jingyan; Sui, Hong

    2011-01-01

    The application of water washing technology for recycling an organic composite solvent consisting of hexane and pentane (4:1; TU-A solvent) was investigated for extracting total petroleum hydrocarbons (TPH) from contaminated soil. The effects of water volume, water temperature, washing time and initial concentration of solvent were evaluated using orthogonal experiments followed by single factor experiments. Our results showed that the water volume was a statistically signif...

  1. Enantioselective solvent-free Robinson annulation reactions

    Indian Academy of Sciences (India)

    D Rajagopal; R Narayanan; S Swaminathan

    2001-06-01

    The enantioselective cyclization of the prochiral cyclic substrates 1 to 7 and 26, can be carried out in the neat using -proline as catalyst. The substrates 18 to 22 and 27 could not be cyclized with S-proline but could be cyclized with a mixture of -phenylalanine and -camphorsulphonic acid. The enantioselective cyclization of prochiral acyclic triones 45 and 47 and also the racemic tricarbonyl compounds 54 to 57 could also be carried out in the \\text{neat} using -proline as catalyst. The optically active enediones obtained in the above cyclizations could also be obtained directly from 1,3-diones or 2-hydroxymethylene cycloalkanones in a one-pot reaction with methyl vinyl ketone (MVK) and S-proline in the absence of solvents. 13C NMR studies of the one-pot synthesis of S-11 and S-14 reveal that the annulations involve initial formation of an acid-base complex followed by a Michael reaction and then an enantioselective cyclization. Such enantioselective cyclizations probably occur on the surface of -proline crystals.

  2. Bio-refinery of orange peels waste: a new concept based on integrated green and solvent free extraction processes using ultrasound and microwave techniques to obtain essential oil, polyphenols and pectin.

    Science.gov (United States)

    Boukroufa, Meryem; Boutekedjiret, Chahrazed; Petigny, Loïc; Rakotomanomana, Njara; Chemat, Farid

    2015-05-01

    In this study, extraction of essential oil, polyphenols and pectin from orange peel has been optimized using microwave and ultrasound technology without adding any solvent but only "in situ" water which was recycled and used as solvent. The essential oil extraction performed by Microwave Hydrodiffusion and Gravity (MHG) was optimized and compared to steam distillation extraction (SD). No significant changes in yield were noticed: 4.22 ± 0.03% and 4.16 ± 0.05% for MHG and SD, respectively. After extraction of essential oil, residual water of plant obtained after MHG extraction was used as solvent for polyphenols and pectin extraction from MHG residues. Polyphenols extraction was performed by ultrasound-assisted extraction (UAE) and conventional extraction (CE). Response surface methodology (RSM) using central composite designs (CCD) approach was launched to investigate the influence of process variables on the ultrasound-assisted extraction (UAE). The statistical analysis revealed that the optimized conditions of ultrasound power and temperature were 0.956 W/cm(2) and 59.83°C giving a polyphenol yield of 50.02 mgGA/100 g dm. Compared with the conventional extraction (CE), the UAE gave an increase of 30% in TPC yield. Pectin was extracted by conventional and microwave assisted extraction. This technique gives a maximal yield of 24.2% for microwave power of 500 W in only 3 min whereas conventional extraction gives 18.32% in 120 min. Combination of microwave, ultrasound and the recycled "in situ" water of citrus peels allow us to obtain high added values compounds in shorter time and managed to make a closed loop using only natural resources provided by the plant which makes the whole process intensified in term of time and energy saving, cleanliness and reduced waste water.

  3. CHEMICAL STABILITY OF POLYPHENYLENE SULFIDE IN THE NEXT GENERATION SOLVENT FOR CAUSTIC-SIDE SOLVENT EXTRACTION

    Energy Technology Data Exchange (ETDEWEB)

    Fondeur, F.; Fink, S.

    2011-12-08

    The Office of Waste Processing, within the Office of Technology Innovation and Development, is funding the development of an enhanced solvent for deployment at the Savannah River Site for removal of cesium from High Level Waste. For simplicity, this solvent is referred to as the Next Generation Solvent (NGS). The technical effort is collaboration between Oak Ridge National Laboratory (ORNL), Savannah River National Laboratory (SRNL), and Argonne National Laboratory. The initial deployment target envisioned for the technology was within the Modular Caustic-Side Solvent Extraction Unit (MCU). Deployment of a new chemical within an existing facility requires verification that the chemical components are compatible with the installed equipment. In the instance of a new organic solvent, the primary focus is on compatibility of the solvent with polyphenylene sulfide (PPS), the polymer used in the coalescers within MCU. This report provides the data from exposing PPS polymer to NGS. The test was conducted over a three month period. PPS is remarkably stable in the presence of the next generation solvent. Testing showed no indication of swelling or significant leaching. Preferential sorption of the Modifier on PPS was observed but the same behavior occurs with the baseline solvent. Therefore, PPS coalescers exposed to the NGS are expected to perform comparably to those in contact with the baseline solvent.

  4. The use of environmentally sustainable bio-derived solvents in solvent extraction applications-A review

    Institute of Scientific and Technical Information of China (English)

    Zheng Li; Kathryn H. Smith; Geoffrey W. Stevens

    2016-01-01

    Replacement of volatile organic compounds (VOCs) by greener or more environmental y sustainable solvents is becoming increasingly important due to the increasing health and environmental concerns as wel as economic pressures associated with VOCs. Solvents that are derived from biomass, namely bio-derived solvents, are a type of green solvent that have attracted intensive investigations in recent years because of their advantages over con-ventional VOCs, such as low toxicity, biodegradability and renewability. This review aims to summarize the use of bio-derived solvents in solvent extraction applications, with special emphasis given to utilization of biodiesels and terpenes. Compared with the conventional VOCs, the overall performance of these bio-derived solvents is comparable in terms of extraction yields and selectivity for natural product extraction and no difference was found for metal extraction. To date most researchers have focused on laboratory scale thermodynamics studies. Future work is required to develop and test new bio-derived solvents and understand the kinetic performance as well as solvent extraction pilot plant studies.

  5. Influence of Energy on Solvent Diffusion in Polymer/Solvent Systems

    Institute of Scientific and Technical Information of China (English)

    HUHuijun; JIANGWenhua; 等

    2002-01-01

    The Vrentas-Duda free-volume theory has been extensively used to correlate or predict the solvent diffusion coefficient of a polymer/solvent system.The energy term in the free volume diffusion equation is difficult to estimate,so the energy term was usually neglected in previous predictive versions of the free volume diffusion coefficient equation.Recent studies show that the energy effect is very important even above the glass transition temperature of the system. In this paper, a new evaluation method of the energy term is proposed,that is the diffusion energy at different solvent concentrations is assumed to be a linear function of the solvent diffusion energy in pure solvents and that in polymers under the condition that the solvent in infinite dilution.By taking consideration of the influence of energy on the solvent diffustion,the prediction of solvent diffusion coefficient was preformed for three polymer/solvent systems over a wide range of concentrations and temperatures.The results show an improvement on the predictive capability of the free volume diffusion theory.

  6. NMR Chemical Shift Ranges of Urine Metabolites in Various Organic Solvents

    Science.gov (United States)

    Görling, Benjamin; Bräse, Stefan; Luy, Burkhard

    2016-01-01

    Signal stability is essential for reliable multivariate data analysis. Urine samples show strong variance in signal positions due to inter patient differences. Here we study the exchange of the solvent of a defined urine matrix and how it affects signal and integral stability of the urinary metabolites by NMR spectroscopy. The exchange solvents were methanol, acetonitrile, dimethyl sulfoxide, chloroform, acetone, dichloromethane, and dimethyl formamide. Some of these solvents showed promising results with a single batch of urine. To evaluate further differences between urine samples, various acid, base, and salt solutions were added in a defined way mimicking to some extent inter human differences. Corresponding chemical shift changes were monitored. PMID:27598217

  7. Computational simulations on the fish-type-Ⅱ antifreeze protein-ice-solvent system

    Institute of Scientific and Technical Information of China (English)

    LIU Kai; WANG Yan; TAN Hongwei; CHEN Guangju; TONG Zhenhe

    2007-01-01

    Based on the computational simulation with the vacuum environment for the fish-type-Ⅱ antifreeze proteinice-solvent (water)system,the multi-complex system of the antifreeze protein-ice-water has been constructed and calculated.We have studied the interaction of such proteinice system with water solvent through the dynamics simulation with 350 ps.By employing the Molecular Dynamics simulation and semi-empirical method calculation,we have further investigated the interface properties of the antifreeze protein and ice crystal combined system.Consequently,a water solvent affects significantly the properties of this combined system.

  8. NMR Chemical Shift Ranges of Urine Metabolites in Various Organic Solvents

    Directory of Open Access Journals (Sweden)

    Benjamin Görling

    2016-09-01

    Full Text Available Signal stability is essential for reliable multivariate data analysis. Urine samples show strong variance in signal positions due to inter patient differences. Here we study the exchange of the solvent of a defined urine matrix and how it affects signal and integral stability of the urinary metabolites by NMR spectroscopy. The exchange solvents were methanol, acetonitrile, dimethyl sulfoxide, chloroform, acetone, dichloromethane, and dimethyl formamide. Some of these solvents showed promising results with a single batch of urine. To evaluate further differences between urine samples, various acid, base, and salt solutions were added in a defined way mimicking to some extent inter human differences. Corresponding chemical shift changes were monitored.

  9. NMR Chemical Shift Ranges of Urine Metabolites in Various Organic Solvents.

    Science.gov (United States)

    Görling, Benjamin; Bräse, Stefan; Luy, Burkhard

    2016-01-01

    Signal stability is essential for reliable multivariate data analysis. Urine samples show strong variance in signal positions due to inter patient differences. Here we study the exchange of the solvent of a defined urine matrix and how it affects signal and integral stability of the urinary metabolites by NMR spectroscopy. The exchange solvents were methanol, acetonitrile, dimethyl sulfoxide, chloroform, acetone, dichloromethane, and dimethyl formamide. Some of these solvents showed promising results with a single batch of urine. To evaluate further differences between urine samples, various acid, base, and salt solutions were added in a defined way mimicking to some extent inter human differences. Corresponding chemical shift changes were monitored. PMID:27598217

  10. Performance Comparison of Environmentally Friendly Water-based Chemical Milling Peelable Adhesive and Solvent-based Products in the Chemical Milling of Aerospace Aluminum Alloy%环保型水基化铣可剥胶与溶剂型产品在航天铝合金材料化铣加工中的性能对比研究

    Institute of Scientific and Technical Information of China (English)

    王帅; 于钦泰; 杜丽梅

    2012-01-01

    Performance test of chemical milling peelable adhesive and four kinds of solvent - based products of YXR-H01 non - toxic latex on the chemical milling of aerospace aluminum alloy with chemical milling depth of more than 15 mm was carried out. Alkali resistance, engraved type property and corrosion ratio of five kinds of chemical milling peelable adhesive were compared. The test proved that after 20 h boiled in alkali and 800rain worked in chemical milling, no phenomenon of drain erosion, through erosion and lift the plastic for YXR-H01 non-toxic latex chemical milling peelable adhesive was observed. The ratio of corrosion is 0.98. Its chemistry milling performance is better than that of the solvent products, and is en- vironmental non-toxic.%对YXR—H01型无毒胶乳化铣可剥胶与4种溶剂型产品,在化铣深度超过15mm的航天用铝合金材料上的使用性能进行了试验。主要对5种化铣可剥胶在化铣加工中的耐碱性、刻型性、腐蚀比等进行了对比测试。试验证明:YXR—H01型无毒胶乳化铣可剥胶在20h煮碱、800min化铣加工中,无漏蚀、透蚀、掀胶现象,腐蚀比为0.98,化铣性能优于溶剂型产品,并具有无毒环保特点。

  11. Stability of the Caustic-Side Solvent Extraction (CSSX) Process Solvent: Effect of High Nitrite on Solvent Nitration

    Energy Technology Data Exchange (ETDEWEB)

    Bonnesen, P.V.

    2002-06-26

    The purpose of this investigation was to determine whether nitrated organic compounds could be formed during operation of the Caustic-Side Solvent Extraction (CSSX) process, and whether such compounds would present a safety concern. The CSSX process was developed to remove cesium from alkaline high-level salt waste stored at the US Department of Energy Savannah River Site (SRS). The solvent is composed of the cesium extractant calix[4]arene-bis-(4-tert-octylbenzo-crown-6) (BOBCalixC6), a fluorinated alcohol phase modifier, tri-n-octylamine (TOA), and an isoparaffinic diluent (Iospar{reg_sign}). During the CSSX process, the solvent is expected to be exposed to high concentrations of nitrate and nitrite dissolved in the alkaline waste feed. The solvent will also be exposed to dilute (50 mM) nitric acid solutions containing low concentrations of nitrite during scrubbing, followed by stripping with 1 mM nitric acid. The solvent is expected to last for one year of plant operation, and the temperatures the solvent may experience during the process could range from as low as 15 C to as high as 35 C. Excursions from standard process conditions could result in the solvent experiencing higher temperatures, as well as concentrations of nitrate, nitrite, and most importantly nitric acid, that exceed normal operating conditions. Accordingly, conditions may exist where nitration reactions involving the solvent components, possibly leading to other chemical reactions stemming from nitration reactions, could occur. To model such nitration reactions, the solvent was exposed to the types of nitrate- and nitrite-containing solutions that might be expected to be encountered during the process (even under off-normal conditions), as a function of time, temperature, and concentration of nitrate, nitrite, and nitric acid. The experiments conducted as part of this report were designed to examine the more specific effect that high nitrite concentrations could have on forming nitrated

  12. Effect of solvent on crystallization behavior of xylitol

    Science.gov (United States)

    Hao, Hongxun; Hou, Baohong; Wang, Jing-Kang; Lin, Guangyu

    2006-04-01

    Effect of organic solvents content on crystallization behavior of xylitol was studied. Solubility and crystallization kinetics of xylitol in methanol-water system were experimentally determined. It was found that the solubility of xylitol at various methanol content all increases with increase of temperature. But it decreases when increasing methanol content at constant temperature. Based on the theory of population balance, the nucleation and growth rates of xylitol in methanol-water mixed solvents were calculated by moments method. From a series of experimental population density data of xylitol gotten from a batch-operated crystallizer, parameters of crystal nucleation and growth rate equations at different methanol content were got by the method of nonlinear least-squares. By analyzing, it was found that the content of methanol had an apparent effect on nucleation and growth rate of xylitol. At constant temperature, the nucleation and growth rate of xylitol all decrease with increase of methanol content.

  13. COMPUTER SIMULATION OF A SINGLE POLYMER CHAIN IN DIFFERENT SOLVENTS

    Institute of Scientific and Technical Information of China (English)

    Yue-li Zheng; Rong Chen; De-lu Zhao; Da-cheng Wu

    2002-01-01

    In the present paper, the behavior of a single polymer chain under various solvent conditions was modeled by self-avoiding walks (SAW) with nearest neighbors attraction △ε on a simple cubic lattice. Determination of the θ-condition was based on the numerical results of the mean square radius of gyration and end-to-end distance. It was found that at the θtemperature △ε/kT equals -0.27. The exponents α in the Mark-Houwink equation with different interaction parameters are consistent with the results of experiments: under θ-condition, α= 0.5, and for a good solvent α = 0.74-0.84, respectively.

  14. Assessing the toxicity and biodegradability of deep eutectic solvents.

    Science.gov (United States)

    Wen, Qing; Chen, Jing-Xin; Tang, Yu-Lin; Wang, Juan; Yang, Zhen

    2015-08-01

    Deep eutectic solvents (DESs) have emerged as a new type of promising ionic solvents with a broad range of potential applications. Although their ecotoxicological profile is still poorly known, DESs are generally regarded as "green" because they are composed of ammonium salts and H-bond donors (HBDs) which are considered to be eco-friendly. In this work, cholinium-based DESs comprised of choline chloride (ChCl) and choline acetate (ChAc) as the salt and urea (U), acetamide (A), glycerol (G) and ethylene glycol (EG) as the HBD were evaluated for their toxic effects on different living organisms such as Escherichia coli (a bacterium), Allium sativum (garlic, a plant) and hydra (an invertebrate), and their biodegradabilities were assessed by means of closed bottle tests. These DESs possessed an anti-bacterial property and exhibited inhibitory effects on the test organisms adopted, depending on the composition and concentration of the DES. The mechanism for the impact of DESs and their components on different living organisms can be associated to their interactions with the cellular membranes. Not all DESs can be considered readily biodegradable. By extending the limited knowledge about the toxicity and biodegradation of this particular solvent family, this investigation on DESs provides insight into our structure-based understanding of their ecotoxicological behavior. PMID:25800513

  15. Solvent Hold Tank Sample Results For MCU-15-750-751-752-: June Monthly Sample

    Energy Technology Data Exchange (ETDEWEB)

    Fondeur, F. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Taylor-Pashow, K. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-10-07

    Savannah River National Laboratory (SRNL) received one set of Solvent Hold Tank (SHT) samples (MCU-15-750, MCU-15-751, and MCU-15-752), pulled on 06/22/2015 for analysis. The samples were combined and analyzed for composition. Analysis of the composite sample MCU-15-750-751-752 indicated a low concentration (~ 49 % of nominal) of the suppressor (TiDG) and slightly lower than nominal concentrations of the extractant (MaxCalix), and of the modifier (Cs-7SB) in the solvent. This analysis confirms the addition of TiDG, MaxCalix, and modifier to the solvent in February 2015. Based on the current monthly sample, the levels of TiDG, MaxCalix, and modifier are sufficient for continuing operation without adding a trim at this time but it is recommended that an addition of TiDG, modifier and Isopar™L should be made in the near future. No impurities above the 1000 ppm level were found in this solvent by the Semi-Volatile Organic Analysis (SVOA). No impurities were observed in the Hydrogen Nuclear Magnetic Resonance (HNMR). In addition, up to 13.9 micrograms of mercury per gram of solvent (or 11.5 µg/mL) was detected in this sample. The laboratory will continue to monitor the quality of the solvent in particular for any new impurities or degradation of the solvent components.

  16. Solvent Hold Tank Sample Results for MCU-15-556-557-558. March 2015 Monthly Sample

    Energy Technology Data Exchange (ETDEWEB)

    Fondeur, F. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Taylor-Pashow, K. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-05-04

    Savannah River National Laboratory (SRNL) received one set of Solvent Hold Tank (SHT) samples (MCU-15-556, MCU-15-557, and MCU-15-558), pulled on 03/16/2015 for analysis. The samples were combined and analyzed for composition. Analysis of the composite sample MCU-15-556-557-558 indicated a low concentration (~ 78 % of nominal) of the suppressor (TiDG) and concentrations of the extractant (MaxCalix), and of the modifier (CS-7SB) in the solvent that were slightly lower than nominal. This analysis confirms the addition of TiDG, MaxCalix, and modifier to the solvent in February 2015. Based on the current monthly sample, the levels of TiDG, MaxCalix, and modifier are sufficient for continuing operation without adding a trim at this time. No impurities above the 1000 ppm level were found in this solvent by the Semi-Volatile Organic Analysis (SVOA). However, the p-nut vials that delivered the samples contained small (1 mm) droplets of oxidized modifier and amides (as detected by the FTIR analysis). In addition, up to 21 microgram of mercury per gram of solvent (or 17.4 µg/mL) was detected in this sample. The laboratory will continue to monitor the quality of the solvent in particular for any new impurities or degradation of the solvent components.

  17. Properties of polylactide inks for solvent-cast printing of three-dimensional freeform microstructures.

    Science.gov (United States)

    Guo, Shuang-Zhuang; Heuzey, Marie-Claude; Therriault, Daniel

    2014-02-01

    Solvent-cast printing is a highly versatile microfabrication technique that can be used to construct various geometries such as filaments, towers, scaffolds, and freeform circular spirals by the robotic deposition of a polymer solution ink onto a moving stage. In this work, we have performed a comprehensive characterization of the solvent-cast printing process using polylactide (PLA) solutions by analyzing the flow behavior of the solutions, the solvent evaporation kinetics, and the effect of process-related parameters on the crystallization of the extruded filaments. Rotational rheometry at low to moderate shear rates showed a nearly Newtonian behavior of the PLA solutions, while capillary flow analysis based on process-related data indicated shear thinning at high shear rates. Solvent vaporization tests suggested that the internal diffusion of the solvent through the filaments controlled the solvent removal of the extrudates. Different kinds of three-dimensional (3D) structures including a layer-by-layer tower, nine-layer scaffold, and freeform spiral were fabricated, and a processing map was given to show the proper ranges of process-related parameters (i.e., polymer content, applied pressure, nozzle diameter, and robot velocity) for the different geometries. The results of differential scanning calorimetry revealed that slow solvent evaporation could increase the ability of PLA to complete its crystallization process during the filament drying stage. The method developed here offers a new perspective for manufacturing complex structures from polymer solutions and provides guidelines to optimize the various parameters for 3D geometry fabrication.

  18. Phenolic Content and Antioxidant Activity of Hibiscus cannabinus L. Seed Extracts after Sequential Solvent Extraction

    OpenAIRE

    Shahid Iqbal; Maznah Ismail; Noordin Mohd Yusri; Kim Wei Chan

    2012-01-01

    A sequential solvent extraction scheme was employed for the extraction of antioxidant compounds from kenaf (Hibiscus cannabinus L.) seeds. Yield of extracts varied widely among the solvents and was the highest for hexane extract (16.6% based on dry weight basis), while water extract exhibited the highest total phenolic content (18.78 mg GAE/g extract), total flavonoid content (2.49 mg RE/g extract), and antioxidant activities (p < 0.05). DPPH and hydroxyl radical scavenging, β...

  19. Chlorinated solvent replacements recycle/recovery review report

    Energy Technology Data Exchange (ETDEWEB)

    Beal, M.; Hsu, D.; McAtee, R.E.; Weidner, J.R. (EG and G Idaho, Inc., Idaho Falls, ID (United States)); Berg, L.; McCandless, F.P.; Waltari, S.; Peterson, C. (Montana State Univ., Bozeman, MT (United States). Dept. of Chemical Engineering)

    1992-08-01

    This report is a literature review of waste solvents recycle/recovery methods and shows the results of solvent separations using membrane and distillation technologies. The experimental solvent recovery methods were conducted on solvent replacements for chlorinated solvents at Montana State University. The literature review covers waste solvents separation using distillation, membranes decantation, filtration, carbon adsorption, solvent extraction, and other vapor-phase separation techniques. The results of this study identify solvent distillation methods as the most common separation technique. The alternative separation methods typically supplement distillation. The study shows the need for industries to identify waste solvent disposal methods and investigate the economics of waste solvent recycling as a possible waste reduction method.

  20. Comparison between a Water-Based and a Solvent-Based Impregnation Method towards Dispersed CuO/SBA-15 Catalysts: Texture, Structure and Catalytic Performance in Automotive Exhaust Gas Abatement

    Directory of Open Access Journals (Sweden)

    Qi Xin

    2016-10-01

    Full Text Available Supported copper oxide nanoparticles are a potential candidate for replacing the rare and expensive precious metals within the automotive three-way catalyst. However, a well-designed dispersion method is necessary to allow a stable high loading of active material, compensating its lower intrinsic activity and stability. In this work, a CuO-loaded SBA-15 catalyst has been manufactured by two methods. The ammonia-driven deposition precipitation (ADP and the molecular designed dispersion (MDD methods are both considered as efficient deposition methods to provide well-dispersed copper oxide-based catalysts. Their morphology, copper dispersion and the chemical state of copper were characterized and compared. Due to the differences in the synthesis approach, a difference in the obtained copper oxide phases has been observed, leading to a distinct behavior in the catalytic performance. The structure-activity correlation of both catalysts has also been revealed for automotive exhaust gas abatement. Results demonstrate that various copper species can be formed depending on the precursor–support interaction, affecting selectivity and conversion during the catalytic reaction.

  1. Recommended methods for purification of solvents and tests for impurities

    CERN Document Server

    Coetzee, J F

    1982-01-01

    Recommended Methods for Purification of Solvents and Tests for Impurities is a compilation of recommended procedures for purification of solvents and tests for solvent impurities. Ten solvents are covered: acetonitrile, sulfolane, propylene carbonate, dimethyl sulfoxide, dimethylformamide, hexamethylphosphoramide, pyridine, ethylenediamine, N-methylacetamide, and N-methylpropionamide. This book is comprised of 12 chapters and opens with an introduction to general aspects of impurity effects. The rationale for the selection of solvent is explained, and the relative reactivities of solutes in di

  2. Alternative Solvents through Green Chemistry Project

    Science.gov (United States)

    Hintze, Paul E.; Quinn, Jacqueline

    2014-01-01

    Components in the aerospace industry must perform with accuracy and precision under extreme conditions, and surface contamination can be detrimental to the desired performance, especially in cases when the components come into contact with strong oxidizers such as liquid oxygen. Therefore, precision cleaning is an important part of a components preparation prior to utilization in aerospace applications. Current cleaning technologies employ a variety of cleaning agents, many of which are halogenated solvents that are either toxic or cause environmental damage. Thus, this project seeks to identify alternative precision cleaning solvents and technologies, including use of less harmful cleaning solvents, ultrasonic and megasonic agitation, low-pressure plasma cleaning techniques, and supercritical carbon dioxide extraction. Please review all data content found in the Public Data tab located at: https:techport.nasa.govview11697public

  3. Thermal Characterization of Nanofluids with Different Solvents

    Science.gov (United States)

    Jiménez-Pérez, J. L.; Cruz-Orea, A.; Sánchez-Ramírez, J. F.; Sánchez-Sinencio, F.; Martínez-Pérez, L.; López Muñoz, G. A.

    2009-08-01

    Thermal lens spectrometry (TLS) and photopyroelectric (PPE) techniques were used to obtain the thermal diffusivity and effusivity of different nanofluid samples. The thermal effusivity of these samples was obtained by the PPE technique in a front detection configuration. In the case of the determination of the thermal diffusivity, TLS was used for the different solvents in the presence of gold nanoparticles (nanofluids). In this technique, an Ar+ laser and intensity stabilized He-Ne laser were used as the heating source and probe beam, respectively. The experimental results showed that thermal diffusivity values of the studied solvents (water, ethanol, and ethylene glycol) were enhanced by the presence of gold nanoparticles. Comparisons with literature values show good agreement with pure solvents. These techniques are applicable for all kind of liquid samples, including semitransparent ones.

  4. 300 Area solvent evaporator closure plan

    International Nuclear Information System (INIS)

    This document describes activities for the closure of a dangerous waste treatment tank facility, owned and operated by the US Department of Energy-Richland Operations Office (DOE-RL) and co-operated by the Westinghouse Hanford Company (Westinghouse Hanford). This tank treatment facility is the 300 Area Solvent Evaporator (300 ASE), which was located in the 300 Area of the Hanford Site from 1975 to 1986, and was managed for the DOE-RL by UNC Nuclear Industries, Incorporated. The 300 ASE evaporator unit was a modified load lugger (dumpster) in which solvent wastes were evaporated, and the adjacent 333 East Concrete Pad, where 55-gallon barrels of waste solvents were temporarily stored while awaiting liquid transfers into the evaporator. 26 refs., 14 figs., 6 tabs

  5. Efficient organic solar cells processed from hydrocarbon solvents

    Science.gov (United States)

    Zhao, Jingbo; Li, Yunke; Yang, Guofang; Jiang, Kui; Lin, Haoran; Ade, Harald; Ma, Wei; Yan, He

    2016-02-01

    Organic solar cells have desirable properties, including low cost of materials, high-throughput roll-to-roll production, mechanical flexibility and light weight. However, all top-performance devices are at present processed using halogenated solvents, which are environmentally hazardous and would thus require expensive mitigation to contain the hazards. Attempts to process organic solar cells from non-halogenated solvents lead to inferior performance. Overcoming this hurdle, here we present a hydrocarbon-based processing system that is not only more environmentally friendly but also yields cells with power conversion efficiencies of up to 11.7%. Our processing system incorporates the synergistic effects of a hydrocarbon solvent, a novel additive, a suitable choice of polymer side chain, and strong temperature-dependent aggregation of the donor polymer. Our results not only demonstrate a method of producing active layers of organic solar cells in an environmentally friendly way, but also provide important scientific insights that will facilitate further improvement of the morphology and performance of organic solar cells.

  6. Effect of solvent extraction on Tunisian esparto wax composition

    Directory of Open Access Journals (Sweden)

    Saâd Inès

    2016-08-01

    Full Text Available The increase of needs for renewable and vegetable based materials will help to drive the market growth of vegetable waxes. Because of their highly variable composition and physicochemical properties, plant waxes have found numerous applications in the: food, cosmetic, candle, coating, polish etc... The aim of this project is to determine the effect of solvent extraction (petroleum ether and ethanol on Tunisian esparto wax composition. The GC-MS was applied in order to determine the waxes compositions. Then, physicochemical parameters of these two samples of waxes: acid value, saponification value, iodine value and melting point were measured in order to deduct their properties and possible fields of uses. Results showed that esparto wax composition depended on the solvent extraction and that major components of the two samples of waxes were: alkanes, esters of fatty acids and phenols. Furthermore, esparto waxes were characterized by an antioxidant and antibacterial activities but the potential of these activities depended on the solvent of wax extraction.

  7. Solvent-resistant microporous polymide membranes

    Science.gov (United States)

    Miller, Warren K.; McCray, Scott B.; Friesen, Dwayne T.

    1998-01-01

    An asymmetric microporous membrane with exceptional solvent resistance and highly desirable permeability is disclosed. The membrane is made by a solution-casting or solution-spinning process from a copolyamic acid comprising the condensation reaction product in a solvent of at least three reactants selected from certain diamines and dianhydrides and post-treated to imidize and in some cases cross-link the copolyamic acid. The membrane is useful as an uncoated membrane for ultrafiltration, microfiltration, and membrane contactor applications, or may be used as a support for a permselective coating to form a composite membrane useful in gas separations, reverse osmosis, nanofiltration, pervaporation, or vapor permeation.

  8. Thermal extraction of bamboo with various solvents

    OpenAIRE

    Kim, Junghee

    2010-01-01

    This thesis is to describe the potential of improvement by liquefaction with various solvents in pyrolysis in terms of conversion of bamboo to gas and liquid and quality of the bio-oils and residues produced. Fluidised sand bath and pressure gauge reactor were used for pyrolysis. The reactor was coupled with bamboo and a solvent and after 1 hour of pyrolysis and liquefaction at 410°C, the gas produced was collected in gas bag. To extract compounds uniformly from the chemically decomposed...

  9. Green extraction of grape skin phenolics by using deep eutectic solvents.

    Science.gov (United States)

    Cvjetko Bubalo, Marina; Ćurko, Natka; Tomašević, Marina; Kovačević Ganić, Karin; Radojčić Redovniković, Ivana

    2016-06-01

    Conventional extraction techniques for plant phenolics are usually associated with high organic solvent consumption and long extraction times. In order to establish an environmentally friendly extraction method for grape skin phenolics, deep eutectic solvents (DES) as a green alternative to conventional solvents coupled with highly efficient microwave-assisted and ultrasound-assisted extraction methods (MAE and UAE, respectively) have been considered. Initially, screening of five different DES for proposed extraction was performed and choline chloride-based DES containing oxalic acid as a hydrogen bond donor with 25% of water was selected as the most promising one, resulting in more effective extraction of grape skin phenolic compounds compared to conventional solvents. Additionally, in our study, UAE proved to be the best extraction method with extraction efficiency superior to both MAE and conventional extraction method. The knowledge acquired in this study will contribute to further DES implementation in extraction of biologically active compounds from various plant sources. PMID:26830574

  10. Vapor Transport of a Volatile Solvent for a Multicomponent Aerosol Droplet

    CERN Document Server

    Feng, James Q

    2015-01-01

    This work presents analytical formulas derived for evaluating vapor transport of a volatile solvent for an isolated multicomponent droplet in a quiescent environment, based on quasi-steady-state approximation. Among multiple solvent components, only one component is considered to be much more volatile than the rest such that other components are assumed to be nonvolatile remaining unchanged in the droplet during the process of (single-component) volatile solvent evaporation or condensation. For evaporating droplet, the droplet size often initially decreases following the familiar "d^2 law" at an accelerated rate. But toward the end, the rate of droplet size change diminishes due to the presence of nonvolatile cosolvent. Such an acceleration-deceleration reversal behavior is unique for evaporating multicomponent droplet, while the droplet of pure solvent has an accelerated rate of size change all the way through the end. This reversal behavior is also reflected in the droplet surface temperature evolution as "...

  11. A radiochemical technique for the establishment of a solvent-independent scale of ion activities in amphiprotic solvents

    International Nuclear Information System (INIS)

    The radiochemical determination of solubilities of hardly soluble compounds of silver (Ph4BAg, AgCl), by means of Ag-110m in amphiprotic solutions is used for setting-up a solvent-independent scale of ion activities based on the concept of the media effect. The media effects of the salts are calculated from the solubility data of the Ag compounds in question. The splitting into the media effects of single ions takes place with the extrathermodynamic assumption of the same media effects for large ions, such as Ph4B- = Ph4As-. A standardized ion activity scale in connection with the activity coefficients for the solvent in question can be established with water as the basic state of the chemical potential. As the sum of the media effects of the single ions gives the media effect of the salt concerned, which is easily obtained from data which are experimentally accessible (solubility, vapour pressure, ion exchange ect.), this method leads to single ion activities of a large number of ions in a multitude of solvents. (orig./LH)

  12. Solvent extraction studies with high-burnup Fast Flux Test Facility fuel in the Solvent Extraction Test Facility

    Energy Technology Data Exchange (ETDEWEB)

    Benker, D.E.; Bigelow, J.E.; Bond, W.D.; Chattin, F.R.; King, L.J.; Kitts, F.G.; Ross, R.G.; Stacy, R.G.

    1986-10-01

    A batch of high-burnup fuel from the Fast Flux Test Facility (FFTF) was processed in the Solvent Extraction Test Facility (SETF) during Campaign 9. The fuel had a burnup of {similar_to}0 MWd/kg and a cooling time of {similar_to} year. Two runs were made with this fuel; in the first, the solvent contained 30% tri-n-butyl phosphate (TBP) and partitioning of the uranium and plutonium was effected by reducing the plutonium with hydroxylamine nitrate (HAN); in the second, the solvent contained 10% TBP and a low operating temperature was used in an attempt to partition without reducing the plutonium valence. The plutonium reoxidation problem, which was present in previous runs that used HAN, may have been solved by lowering the temperature and acidity in the partition contactor. An automatic control system was used to maintain high loadings of heavy metals in the coextraction-coscrub contactor in order to increase its efficiency while maintaining low losses of uranium and plutonium to the aqueous raffinate. An in-line photometer system was used to measure the plutonium concentration in an intermediate extraction stage; and based on this data, a computer algorithm determined the appropriate adjustments in the addition rate of the extractant. The control system was successfully demonstrated in a preliminary run with purified uranium. However, a variety of equipment and start up problems prevented an extended demonstration from being accomplished during the runs with the FFTF fuel.

  13. Experimental approach versus COSMO-RS assisted solvent screening for predicting the solubility of rapeseed oil

    Directory of Open Access Journals (Sweden)

    Sicaire Anne-Gaëlle

    2015-07-01

    Full Text Available Vegetable oils take a large part in industry for food and non-food applications. However the extraction process of oil from oilseeds includes a solvent extraction step using hexane. Despite its various advantages it presents numerous drawbacks; it is sourced from petroleum, it has a high flammability and it appears to be dangerous for health and environment (CMR2. This study presents a theoretical screening using COSMO-RS simulations of the relative solubility of vegetable oil constituents regarding several bio-based solvents as well as an experimental screening of the efficiency of these solvents. The aim is to correlate simulations and experiments and give a preliminary evaluation for the substitution of hexane by bio-based solvents for the extraction of vegetable oils. Differences between theory and practice have been noticed for several solvents such as terpenes that appeared to be good candidates in theory and that were in fact the solvents that gave the lowest extraction yield.

  14. Rectification of nanopores in aprotic solvents - transport properties of nanopores with surface dipoles

    Science.gov (United States)

    Plett, Timothy; Shi, Wenqing; Zeng, Yuhan; Mann, William; Vlassiouk, Ivan; Baker, Lane A.; Siwy, Zuzanna S.

    2015-11-01

    Nanopores have become a model system to understand transport properties at the nanoscale. We report experiments and modeling of ionic current in aprotic solvents with different dipole moments through conically shaped nanopores in a polycarbonate film and through glass nanopipettes. We focus on solutions of the salt LiClO4, which is of great importance in modeling lithium based batteries. Results presented suggest ion current rectification observed results from two effects: (i) adsorption of Li+ ions to the pore walls, and (ii) a finite dipole moment rendered by adsorbed solvent molecules. Properties of surfaces in various solvents were probed by means of scanning ion conductance microscopy, which confirmed existence of an effectively positive surface potential in aprotic solvents with high dipole moments.Nanopores have become a model system to understand transport properties at the nanoscale. We report experiments and modeling of ionic current in aprotic solvents with different dipole moments through conically shaped nanopores in a polycarbonate film and through glass nanopipettes. We focus on solutions of the salt LiClO4, which is of great importance in modeling lithium based batteries. Results presented suggest ion current rectification observed results from two effects: (i) adsorption of Li+ ions to the pore walls, and (ii) a finite dipole moment rendered by adsorbed solvent molecules. Properties of surfaces in various solvents were probed by means of scanning ion conductance microscopy, which confirmed existence of an effectively positive surface potential in aprotic solvents with high dipole moments. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr06340j

  15. Organic solvent nanofiltration: prospects and application

    International Nuclear Information System (INIS)

    The key lines of research in a new field of the membrane science and technology, viz., organic solvent nanofiltration, are considered. The prospects for its use in chemical, petrochemical and food industries are discussed. Attention is focused on membranes developed for this method.

  16. Organic solvent nanofiltration: prospects and application

    Energy Technology Data Exchange (ETDEWEB)

    Volkov, A V; Korneeva, G A; Tereshchenko, Gennadii F [A. V. Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, Moscow (Russian Federation)

    2008-11-30

    The key lines of research in a new field of the membrane science and technology, viz., organic solvent nanofiltration, are considered. The prospects for its use in chemical, petrochemical and food industries are discussed. Attention is focused on membranes developed for this method.

  17. Mixed Solvent Reactive Recrystallization of Sodium Carbonate

    NARCIS (Netherlands)

    Gaertner, R.S.

    2005-01-01

    Investigation of the reactive recrystallization of trona (sodium sesquicarbonate) and sodium bicarbonate to sodium carbonate (soda) in a mixed solvent led to the design of several alternative, less energy consumptive, economically very attractive process routes for the production of soda from all pr

  18. Ferrier reaction in a deep eutectic solvent.

    Science.gov (United States)

    Rokade, Sunil M; Bhate, Prakash M

    2015-10-13

    A mild and efficient synthesis of 2,3-unsaturated sugar derivatives has been achieved by conducting the Ferrier reaction in a deep eutectic solvent (DES). A wide range of alcohols including primary, secondary, benzylic, and sugar-derived primary alcohols can be used. Advantages include good yields, shorter reaction times and recyclability of DES. PMID:26279523

  19. Structure and Solvent Properties of Microemulsions

    Science.gov (United States)

    Katz, Civia A.; Calzola, Zachary J.; Mbindyo, Jeremiah K. N.

    2008-01-01

    A microscale laboratory experiment to investigate the formation and utility of microemulsions is described. Microemulsions are technologically important fluids that can reduce the use of toxic organic solvents. In the experiment, students prepare a microemulsion and compare the solubility of sudan III dye in the microemulsion and in dodecane. They…

  20. Solvent-Free Synthesis of Chalcones

    Science.gov (United States)

    Palleros, Daniel R.

    2004-01-01

    The synthesis of twenty different chalcones in the absence of solvent is presented. The results indicated that out of the twenty different chalcones investigated seventeen can be obtained in a matter of minutes by mixing the corresponding benzaldehyde and acetophenone in the presence of solid NaOH in a mortar with pestle.

  1. Effect of solvent structure on election reactivity

    International Nuclear Information System (INIS)

    The reactivity of solvated electrons (es-) with efficient (nitrobenzene, acetone) and inefficient (phenol, toluene) scavengers is affected greatly by the solvent composition in 2-propanol/water mixed solvents. 2-Propanol is the only secondary alcohol that is completely miscible with water. The variation of the nitrobenzene rate constant k2 with solvent composition displays four viscosity zones, as in primary and tertiary alcohol/water mixtures. In zone (c), where the Stokes-Smoluchowski equation applies, the nitrobenzene k2 values in the secondary alcohol/water mixtures are situated between those in the primary and tertiary alcohols, due to the relative values of the dielectric permittivity ε. The charge-dipole attraction energy varies at ε-1. The two water-rich zones (c) and (d) are characterized by a large change of viscosity η and a small change in es- solvation energy (trap depth) Er; here k2 for all the scavengers correlates with the inverse of the viscosity. In the two alcohol-rich zones (a) and (b) the change of η is small but that of Er is large; here k2 of inefficient scavengers correlates with the inverse of Er, due to the difficulty of electron transfer out of deeper traps. Activation energies E2 and entropies ΔS2(double dagger) also show composition zone behaviour. The value of ΔS2(double dagger) is more negative for less efficient scavengers; E2 varies less and does not correlate with reactivity of Er. Electron transfer from solvent to inefficient scavenger is driven by solvent rearrangement around the reaction center, reflected in ΔS2(double dagger)

  2. Solvent density mode instability in non-polar solutions

    Indian Academy of Sciences (India)

    Susmita Kar; Ranjit Biswas; J Chakrabarti

    2008-08-01

    We analyse the origin of the multiple long time scales associated with the long time decay observed in non-polar solvation dynamics by linear stability analysis of solvent density modes where the effects of compressibility and solvent structure are systematically incorporated. The coupling of the solute–solvent interactions at both ground and excited states of the solute with the compressibility and solvent structure is found to have important effects on the time scales. The present theory suggests that the relatively longer time constant is controlled by the solvent compressibility, while the solvent structure at the nearest-neighbour length scale dominates the shorter time constant.

  3. Predicting the activity coefficients of free-solvent for concentrated globular protein solutions using independently determined physical parameters.

    Directory of Open Access Journals (Sweden)

    Devin W McBride

    Full Text Available The activity coefficient is largely considered an empirical parameter that was traditionally introduced to correct the non-ideality observed in thermodynamic systems such as osmotic pressure. Here, the activity coefficient of free-solvent is related to physically realistic parameters and a mathematical expression is developed to directly predict the activity coefficients of free-solvent, for aqueous protein solutions up to near-saturation concentrations. The model is based on the free-solvent model, which has previously been shown to provide excellent prediction of the osmotic pressure of concentrated and crowded globular proteins in aqueous solutions up to near-saturation concentrations. Thus, this model uses only the independently determined, physically realizable quantities: mole fraction, solvent accessible surface area, and ion binding, in its prediction. Predictions are presented for the activity coefficients of free-solvent for near-saturated protein solutions containing either bovine serum albumin or hemoglobin. As a verification step, the predictability of the model for the activity coefficient of sucrose solutions was evaluated. The predicted activity coefficients of free-solvent are compared to the calculated activity coefficients of free-solvent based on osmotic pressure data. It is observed that the predicted activity coefficients are increasingly dependent on the solute-solvent parameters as the protein concentration increases to near-saturation concentrations.

  4. Predicting the activity coefficients of free-solvent for concentrated globular protein solutions using independently determined physical parameters.

    Science.gov (United States)

    McBride, Devin W; Rodgers, Victor G J

    2013-01-01

    The activity coefficient is largely considered an empirical parameter that was traditionally introduced to correct the non-ideality observed in thermodynamic systems such as osmotic pressure. Here, the activity coefficient of free-solvent is related to physically realistic parameters and a mathematical expression is developed to directly predict the activity coefficients of free-solvent, for aqueous protein solutions up to near-saturation concentrations. The model is based on the free-solvent model, which has previously been shown to provide excellent prediction of the osmotic pressure of concentrated and crowded globular proteins in aqueous solutions up to near-saturation concentrations. Thus, this model uses only the independently determined, physically realizable quantities: mole fraction, solvent accessible surface area, and ion binding, in its prediction. Predictions are presented for the activity coefficients of free-solvent for near-saturated protein solutions containing either bovine serum albumin or hemoglobin. As a verification step, the predictability of the model for the activity coefficient of sucrose solutions was evaluated. The predicted activity coefficients of free-solvent are compared to the calculated activity coefficients of free-solvent based on osmotic pressure data. It is observed that the predicted activity coefficients are increasingly dependent on the solute-solvent parameters as the protein concentration increases to near-saturation concentrations.

  5. Solvent/Non-Solvent Sintering: A Novel Route to Create Porous Microsphere Scaffolds For Tissue Regeneration

    OpenAIRE

    Justin L Brown; Nair, Lakshmi S.; Laurencin, Cato T.

    2008-01-01

    Solvent/non-solvent sintering creates porous polymeric microsphere scaffolds suitable for tissue engineering purposes with control over the resulting porosity, average pore diameter and mechanical properties. Five different biodegradable biocompatible polyphosphazenes exhibiting glass transition temperatures from −8°C to 41oC and poly(lactide-co-glycolide), (PLAGA) a degradable polymer used in a number of biomedical settings, were examined to study the versatility of the process and benchmark...

  6. Understanding Solvent Effects on the Properties of Two-Dimensional Transition Metal Dichalcogenides.

    Science.gov (United States)

    Choi, Jungwook; Zhang, Hanyu; Du, Haodong; Choi, Jong Hyun

    2016-04-13

    Two-dimensional (2D) transition metal dichalcogenides (TMDCs) have emerged as attractive direct bandgap semiconducting materials with remarkable properties. Recently, TMDC-based electronic and optoelectronic systems have been demonstrated with various chemical doping and functionalization approaches for modulating their physical properties and enhancing device performances. However, the dependence of intrinsic properties of TMDCs on diverse solvents, which are used necessarily in fabrication processes and chemical doping, remains largely unaddressed. Here we report a charge transfer mechanism in TMDCs by commonly used solvents such as chloroform, toluene, acetone, and 2-propanol, which significantly changes the physical properties of monolayer MoS2 and WSe2. We find that the relative difference in electronegativity between solvents and TMDCs drives the transfer of electrons from or to the TMDCs, which results in photoluminescence (PL) enhancement or quenching depending on the change of carrier density in TMDCs. The analysis of exciton and trion spectral weights in MoS2 as a function of solvent electronegativity provides evidence of charge transfer. Finally, conductive atomic force microscopy (C-AFM) on TMDCs before and after immersion in the solvents further supports the charge transfer mechanism and resulting changes in carrier density. Our results highlight the importance of selection of solvents for solution-processed 2D TMDC devices and systems. PMID:27018600

  7. Crosslinked copolyazoles with a zwitterionic structure for organic solvent resistant membranes

    KAUST Repository

    Chisca, Stefan

    2015-01-01

    The preparation of crosslinked membranes with a zwitterionic structure based on a facile reaction between a newly synthesized copolyazole with free OH groups and (3-glycidyloxypropyl)trimethoxysilane (GPTMS) is reported. The new OH-functionalized copolyazole is soluble in common organic solvents, such as tetrahydrofuran (THF), dimethylsulfoxide (DMSO), N,N′-dimethylformamide (DMF) and N-methyl-2-pyrrolidone (NMP) and can be easily processed by phase inversion. After crosslinking with GPTMS, the membranes acquire high solvent resistance. We show the membrane performance and the influence of the crosslinking reaction conditions on the thermal stability, surface polarity, pore morphology, and solvent resistance. By using UV-spectroscopy we monitored the solvent resistance of the membranes in four aggressive solvents (THF, DMSO, DMF and NMP) for 30 days. After this time, only minor changes (less than 2%) were detected for membranes subjected to a crosslinking reaction for 6 hours or longer. Our data suggest that the novel crosslinked membranes can be used for industrial applications in wide harsh environments in the presence of organic solvents.

  8. Absorption and Emission Sensitivity of 2-(2'-Hydroxyphenyl)benzoxazole to Solvents and Impurities.

    Science.gov (United States)

    Yuan, Zhao; Tang, Qing; Sreenath, Kesavapillai; Simmons, J Tyler; Younes, Ali H; Jiang, De-En; Zhu, Lei

    2015-01-01

    2-(2'-Hydroxyphenyl)benzoxazole (HBO) is known for undergoing intramolecular proton transfer in the excited state to result in the emission of its tautomer. A minor long-wavelength absorption band in the range 370-420 nm has been reported in highly polar solvents such as dimethylsulfoxide (DMSO). However, the nature of this species has not been entirely clarified. In this work, we provide evidence that this long-wavelength absorption band might have been caused by base or metal salt impurities that are introduced into the spectral sample during solvent transport using glass Pasteur pipettes. The contamination by base or metal salt could be avoided by using borosilicate glass syringes or nonglass pipettes in sample handling. Quantum chemical calculations conclude that solvent-mediated deprotonation is too energetically costly to occur without the aid of a base of an adequate strength. In the presence of such a base, the deprotonation of HBO and its effect on emission are investigated in dichloromethane and DMSO, the latter of which facilitates deprotonation much more readily than the former. Finally, the absorption and emission spectra of HBO in 13 solvents are reported, from which it is concluded that ESIPT is hindered in polar solvents that are also strong hydrogen bond acceptors.

  9. Solvent hold tank sample results for MCU-16-53-55. January 2016 Monthly sample

    Energy Technology Data Exchange (ETDEWEB)

    Fondeur, F. F. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Jones, D. H. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-03-28

    Savannah River National Laboratory (SRNL) received one set of Solvent Hold Tank (SHT) samples (MCU-16-53-54-55), pulled on 01/25/2016 for analysis. The samples were combined and analyzed for composition. Analysis of the composite sample MCU-16-53-54-55 indicated the Isopar™L, and MaxCalix are at nominal levels. The modifier and TiDG concentrations are 3% and 23 % below their nominal concentrations. This analysis confirms the addition of TiDG, MaxCalix, and modifier to the solvent on November 28, 2015. Based on the current monthly sample, the levels of TiDG, Isopar™L, MaxCalix, and modifier are sufficient for continuing operation but are expected to decrease with time. Periodic characterization and trimming additions to the solvent are recommended. No impurities above the 1000 ppm level were found in this solvent by the Semi-Volatile Organic Analysis (SVOA). No impurities were observed in the Hydrogen Nuclear Magnetic Resonance (HNMR). However, the Fourier transform infra-red spectroscopy (FTIR) method detected trace levels (a few ppm) of amides (a possible degradation product of TiDG). In addition, up to 21 ± 4 micrograms of mercury per gram of solvent (or 17.5 μg/mL) was detected in this sample. There appears to be a possible correlation between the mercury level and the TiDG concentration in the solvent. The current gamma level (9.16 E4 dpm/mL) confirmed that the gamma concentration has returned to previous level where the process operated normally and as expected. The laboratory will continue to monitor the quality of the solvent in particular for any new impurities or degradation of the solvent components.

  10. Recurrent Acute Liver Failure Because of Acute Hepatitis Induced by Organic Solvents

    Science.gov (United States)

    Ito, Daisuke; Tanaka, Tomohiro; Akamatsu, Nobuhisa; Ito, Kyoji; Hasegawa, Kiyoshi; Sakamoto, Yoshihiro; Nakagawa, Hayato; Fujinaga, Hidetaka; Kokudo, Norihiro

    2016-01-01

    Abstract The authors present a case of recurrent acute liver failure because of occupational exposure to organic solvents. A 35-year-old man with a 3-week history of worsening jaundice and flu-like symptoms was admitted to our hospital. Viral hepatitis serology and autoimmune factors were negative. The authors considered liver transplantation, but the patient's liver function spontaneously recovered. Liver biopsy revealed massive infiltration of neutrophils, but the cause of the acute hepatitis was not identified. Four months after discharge, the patient's liver function worsened again. The authors considered the possibility of antinuclear antibody-negative autoimmune hepatitis and initiated steroid treatment, which was effective. Four months after discharge, the patient was admitted for repeated liver injury. The authors started him on steroid pulse therapy, but this time it was not effective. Just before the first admission, he had started his own construction company where he was highly exposed to organic solvents, and thus the authors considered organic solvent-induced hepatitis. Although urine test results for organic solvents were negative, a second liver biopsy revealed severe infiltration of neutrophils, compatible with toxic hepatitis. Again, his liver function spontaneously improved. Based on the pathology and detailed clinical course, including the patient's high exposure to organic solvents since just before the first admission, and the spontaneous recovery of his liver damage in the absence of the exposure, he was diagnosed with toxic hepatitis. The authors strongly advised him to avoid organic solvents. Since then, he has been in good health without recurrence. This is the first report of recurrent acute liver failure because of exposure to organic solvents, which was eventually diagnosed through a meticulous medical history and successfully recovered by avoiding the causative agents. In acute liver failure with an undetermined etiology, clinicians

  11. Recurrent Acute Liver Failure Because of Acute Hepatitis Induced by Organic Solvents: A Case Report.

    Science.gov (United States)

    Ito, Daisuke; Tanaka, Tomohiro; Akamatsu, Nobuhisa; Ito, Kyoji; Hasegawa, Kiyoshi; Sakamoto, Yoshihiro; Nakagawa, Hayato; Fujinaga, Hidetaka; Kokudo, Norihiro

    2016-01-01

    The authors present a case of recurrent acute liver failure because of occupational exposure to organic solvents. A 35-year-old man with a 3-week history of worsening jaundice and flu-like symptoms was admitted to our hospital. Viral hepatitis serology and autoimmune factors were negative. The authors considered liver transplantation, but the patient's liver function spontaneously recovered. Liver biopsy revealed massive infiltration of neutrophils, but the cause of the acute hepatitis was not identified. Four months after discharge, the patient's liver function worsened again. The authors considered the possibility of antinuclear antibody-negative autoimmune hepatitis and initiated steroid treatment, which was effective. Four months after discharge, the patient was admitted for repeated liver injury. The authors started him on steroid pulse therapy, but this time it was not effective. Just before the first admission, he had started his own construction company where he was highly exposed to organic solvents, and thus the authors considered organic solvent-induced hepatitis. Although urine test results for organic solvents were negative, a second liver biopsy revealed severe infiltration of neutrophils, compatible with toxic hepatitis. Again, his liver function spontaneously improved. Based on the pathology and detailed clinical course, including the patient's high exposure to organic solvents since just before the first admission, and the spontaneous recovery of his liver damage in the absence of the exposure, he was diagnosed with toxic hepatitis. The authors strongly advised him to avoid organic solvents. Since then, he has been in good health without recurrence. This is the first report of recurrent acute liver failure because of exposure to organic solvents, which was eventually diagnosed through a meticulous medical history and successfully recovered by avoiding the causative agents. In acute liver failure with an undetermined etiology, clinicians should rule

  12. Enhanced catalysis by solvent improvement. Quarterly technical progress report, 1 April-30 June 1983

    Energy Technology Data Exchange (ETDEWEB)

    Garg, D.; Miller, R.N.; Givens, E.N.; Tarrer, A.R.; Guin, J.A.; Curtis, C.W.

    1983-11-01

    This report describes the results from liquefaction solvent modification, coal liquefaction with original and modified solvents, catalyst selection, coal pretreatment, and pretreatment followed by liquefaction experiments. The effect of liquefaction reaction conditions on product distribution is also covered in this report. Significant removal of nitrogen compounds from coal-derived liquefaction solvent was obtained by treating it with anhydrous hydrochloric acid or silica gel. The removal of nitrogen compounds with HCl or silica gel was also accompanied by 25 to 40% removal of oxygen compounds. Treating liquefaction solvent with aqueous NaOH or zeolite removed significant amounts of phenolic compounds. Oxygen removal was also accompanied by a partial removal of nitrogen compounds. Sequential treatment of coal-derived liquefaction solvent with HCl followed by silica gel or NaOH followed by HCl resulted in complete removal of nitrogen compounds. Liquefying coals in the presence of coal-derived liquefaction solvents modified by the removal of nitrogen or oxygen compounds or both significantly increased the oil yield in the absence of catalyst. The overall coal conversion, however, decreased only slightly with these treated solvents. A significant increase in the oil yield was also noted during catalytic liquefaction with the pretreated solvents. The overall coal conversion also increased during catalytic liquefaction of coal. At a concentration level of 250 ppM metal based on coal molybdenum catalyst was more active than nickel. At this level the activity of molybdenum was also higher than that noted with 1 wt% iron or zinc. Combination of metals such as iron and molybdenum or zinc and molybdenum yielded significantly higher oil yield compared to individual metals alone. 1 ref., 2 figs., 28 tabs.

  13. Chemical approach to solvent removal during nanoencapsulation: its application to preparation of PLGA nanoparticles with non-halogenated solvent

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Youngme [Ewha Womans University, College of Pharmacy (Korea, Republic of); Sah, Eric [University of Notre Dame, College of Science (United States); Sah, Hongkee, E-mail: hsah@ewha.ac.kr [Ewha Womans University, College of Pharmacy (Korea, Republic of)

    2015-11-15

    The objective of this study was to develop a new oil-in-water emulsion-based nanoencapsulation method for the preparation of PLGA nanoparticles using a non-halogenated solvent. PLGA (60–150 mg) was dissolved in 3 ml of methyl propionate, which was vortexed with 4 ml of a 0.5–4 % polyvinyl alcohol solution. This premix was sonicated for 2 min, added into 30 ml of the aqueous polyvinyl alcohol solution, and reacted with 3 ml of 10 N NaOH. Solvent removal was achieved by the alkaline hydrolysis of methyl propionate dissolved in an aqueous phase into water-soluble methanol and sodium propionate. It was a simple but effective technique to quickly harden nanoemulsion droplets into nanoparticles. The appearing PLGA nanoparticles were recovered by ultracentrifugation and/or dialysis, lyophilized with trehalose, and redispersed by water. This nanoencapsulation technique permitted a control of their mean diameters over 151.7 ± 3.8 to 440.2 ± 22.2 nm at mild processing conditions. When the aqueous polyvinyl alcohol concentration was set at ≥1 %, nanoparticles showed uniform distributions with polydispersity indices below 0.1. There were no significant changes in their mean diameters and size distribution patterns before and after lyophilization. When mestranol was encapsulated into nanoparticles, the drug was completely nanoencapsulated: depending on experimental conditions, their encapsulation efficiencies were determined to be 99.4 ± 7.2 to 105.8 ± 6.3 %. This simple, facile nanoencapsulation technique might have versatile applications for the preparation of polymeric nanoparticulate dosage forms.Graphical AbstractSchematic illustration of an innovative chemical approach to solvent removal during nanoencapsulation. Methyl propionate present in the aqueous continuous phase reacts with sodium hydroxide, thereby producing methanol and sodium propionate. Its alkaline hydrolysis allows the continuous extraction of the solvent out of nanoemulsion

  14. Natural deep eutectic solvents as new potential media for green technology

    International Nuclear Information System (INIS)

    Highlights: ► Natural products were used as a source for deep eutectic solvents and ionic liquids. ► We define own chemical and physical properties of natural deep eutectic solvents. ► Interaction between natural deep eutectic solvents and solutes was confirmed by NMR. ► The developed natural deep eutectic solvents were applied as green media. - Abstract: Developing new green solvents is one of the key subjects in Green Chemistry. Ionic liquids (ILs) and deep eutectic solvents, thus, have been paid great attention to replace current harsh organic solvents and have been applied to many chemical processing such as extraction and synthesis. However, current ionic liquids and deep eutectic solvents have still limitations to be applied to a real chemical industry due to toxicity against human and environment and high cost of ILs and solid state of most deep eutectic solvents at room temperature. Recently we discovered that many plant abundant primary metabolites changed their state from solid to liquid when they were mixed in proper ratio. This finding made us hypothesize that natural deep eutectic solvents (NADES) play a role as alternative media to water in living organisms and tested a wide range of natural products, which resulted in discovery of over 100 NADES from nature. In order to prove deep eutectic feature the interaction between the molecules was investigated by nuclear magnetic resonance spectroscopy. All the tested NADES show clear hydrogen bonding between components. As next step physical properties of NADES such as water activity, density, viscosity, polarity and thermal properties were measured as well as the effect of water on the physical properties. In the last stage the novel NADES were applied to the solubilization of wide range of biomolecules such as non-water soluble bioactive natural products, gluten, starch, and DNA. In most cases the solubility of the biomolecules evaluated in this study was greatly higher than water. Based on the

  15. Natural deep eutectic solvents as new potential media for green technology

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Yuntao [Natural Products Laboratory, Institute of Biology, Leiden University, 2300 RA Leiden (Netherlands); Spronsen, Jaap van; Witkamp, Geert-Jan [Laboratory for Process Equipment, Delft University of Technology, Delft (Netherlands); Verpoorte, Robert [Natural Products Laboratory, Institute of Biology, Leiden University, 2300 RA Leiden (Netherlands); Choi, Young Hae, E-mail: y.choi@chem.leidenuniv.nl [Natural Products Laboratory, Institute of Biology, Leiden University, 2300 RA Leiden (Netherlands)

    2013-03-05

    Highlights: ► Natural products were used as a source for deep eutectic solvents and ionic liquids. ► We define own chemical and physical properties of natural deep eutectic solvents. ► Interaction between natural deep eutectic solvents and solutes was confirmed by NMR. ► The developed natural deep eutectic solvents were applied as green media. - Abstract: Developing new green solvents is one of the key subjects in Green Chemistry. Ionic liquids (ILs) and deep eutectic solvents, thus, have been paid great attention to replace current harsh organic solvents and have been applied to many chemical processing such as extraction and synthesis. However, current ionic liquids and deep eutectic solvents have still limitations to be applied to a real chemical industry due to toxicity against human and environment and high cost of ILs and solid state of most deep eutectic solvents at room temperature. Recently we discovered that many plant abundant primary metabolites changed their state from solid to liquid when they were mixed in proper ratio. This finding made us hypothesize that natural deep eutectic solvents (NADES) play a role as alternative media to water in living organisms and tested a wide range of natural products, which resulted in discovery of over 100 NADES from nature. In order to prove deep eutectic feature the interaction between the molecules was investigated by nuclear magnetic resonance spectroscopy. All the tested NADES show clear hydrogen bonding between components. As next step physical properties of NADES such as water activity, density, viscosity, polarity and thermal properties were measured as well as the effect of water on the physical properties. In the last stage the novel NADES were applied to the solubilization of wide range of biomolecules such as non-water soluble bioactive natural products, gluten, starch, and DNA. In most cases the solubility of the biomolecules evaluated in this study was greatly higher than water. Based on the

  16. A facile one-step solution deposition via non-solvent/solvent mixture for efficient organometal halide perovskite light-emitting diodes.

    Science.gov (United States)

    Jiao, Bo; Zhu, Xiaobo; Wu, Wen; Dong, Hua; Xia, Bin; Xi, Jun; Lei, Ting; Hou, Xun; Wu, Zhaoxin

    2016-06-01

    Although organometal halide perovskite materials have shown great potential in light-emitting diodes, their performance is greatly restricted by the poor morphology of the perovskite layer. In this work, we demonstrate a facile one-step solution method to improve the perovskite film morphology via a non-solvent/solvent mixture. An efficient CH3NH3PbBr3-based light-emitting diode was prepared with a chlorobenzene/N,N-dimethylformamide mixed solvent. A high efficiency of 0.54 cd A(-1) is demonstrated, which is 22 times higher than that of a device fabricated by a traditional one-step solution process. Furthermore, the uniformity of the emission region and the device stability are strongly improved by this facile one-step solution process. Our work paves a new way for the morphological control of perovskite films for application in light-emitting diodes.

  17. Selection and evaluation of alternative solvents for caprolactam extraction

    NARCIS (Netherlands)

    Delden, van Mathijs L.; Kuipers, Norbert J.M.; Haan, de André B.

    2006-01-01

    Because of the strict legislation for currently applied solvents in the industrial extraction of caprolactam, being benzene, toluene and chlorinated hydrocarbons, a need exists for alternative, environmentally benign solvents. An experimental screening procedure consisting of several steps was used

  18. Organic Solvent Tropical Report [SEC 1 and 2

    Energy Technology Data Exchange (ETDEWEB)

    COWLEY, W.L.

    2000-06-21

    This report provides the basis for closing the organic solvent safety issue. Sufficient information is presented to conclude that risk posed by an unmitigated organic solvent fire is within risk evaluation guidelines.

  19. Occupational exposure to chlorinated and petroleum solvents and mycosis fungoides

    DEFF Research Database (Denmark)

    Morales-Suárez-Varela, Maria M; Olsen, Jørn; Villeneuve, Sara;

    2013-01-01

    To evaluate the potential association between occupational exposure to chlorinated and petroleum solvents and mycosis fungoides (MF).......To evaluate the potential association between occupational exposure to chlorinated and petroleum solvents and mycosis fungoides (MF)....

  20. Charge-transfer complex formation in gelation: the role of solvent molecules with different electron-donating capacities.

    Science.gov (United States)

    Basak, Shibaji; Bhattacharya, Sumantra; Datta, Ayan; Banerjee, Arindam

    2014-05-01

    A naphthalenediimide (NDI)-based synthetic peptide molecule forms gels in a particular solvent mixture (chloroform/aromatic hydrocarbon, 4:1) through charge-transfer (CT) complex formation; this is evident from the corresponding absorbance and fluorescence spectra at room temperature. Various aromatic hydrocarbon based solvents, including benzene, toluene, xylene (ortho, meta and para) and mesitylene, have been used for the formation of the CT complex. The role of different solvent molecules with varying electron-donation capacities in the formation of CT complexes has been established through spectroscopic and computational studies. PMID:24677404