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Sample records for acrylonitrile stanniciv tungstate

  1. Acrylonitrile butadiene rubber (NBR)/manganous tungstate (MnWO4) nanocomposites: Characterization, mechanical and electrical properties

    Science.gov (United States)

    Ramesan, M. T.; Abdu Raheem V., P.; Jayakrishnan, P.; Pradyumnan, P. P.

    2014-10-01

    Nanocomposites of NBR with manganous-tungstate nanoparticles were prepared through vulcanization process. The extent of interaction of nanoparticles with the polymer was studied by FTIR, SEM, XRD, TGA and AC conductivity. FTIR and XRD ascertain the interaction of NBR with MnWO4 nanoparticles. SEM analysis established that the nanopartilces were well dispersed in the macromolecular chain of NBR. The mechanical properties of the nanocomposites were studied as a function of filler loading. The nanocomposites exhibited enhanced thermal stability as seen in TGA. Conductivity and dielectric properties of nanocomposites increase with increase in concentration of MnWO4 nanoparticles (7phr) and thereafter the value decreases.

  2. Equilibrium Adsorption of heavy Metals from Aqueous Solutions onto Poly aniline Stannic(IV) Phosphate Composite

    International Nuclear Information System (INIS)

    El-Zahhar, A.A.; EI-Shourbagy, M.M.; Shady, S.A.

    2012-01-01

    An adsorbent material has been prepared by immobilization of stannic(IV) phosphate within poly aniline composite. The produced adsorbent exhibit a high adsorption potential for Pb(II), Cd(Il) and Zn(lI) from aqueous solutions. The influence of initial metal ion concentration, adsorbent dose, ph and temperature on metal ion removal has been studied. The process was found to follow a first order rate kinetics. Thc intra-particle diffusion of metal ions through pores in the adsorbent was to be the main rate limiting step. The equilibrium data fit well with Langmuir adsorption isotherm model. The selectivity order of the adsorbent towards the metal ions was Pb(Il) > Cd(Il) >Zn(II). The adsorption rate constant and thermodynamic parameters were also given to predict the nature of adsorption

  3. CMS lead tungstate crystals

    CERN Multimedia

    Laurent Guiraud

    2000-01-01

    These crystals are made from lead tungstate, a crystal that is as clear as glass yet with nearly four times the density. They have been produced in Russia to be used as scintillators in the electromagnetic calorimeter on the CMS experiment, part of the LHC project at CERN. When an electron, positron or photon passes through the calorimeter it will cause a cascade of particles that will then be absorbed by these scintillating crystals, allowing the particle's energy to be measured.

  4. Renewable Acrylonitrile Production

    Energy Technology Data Exchange (ETDEWEB)

    Beckham, Gregg T [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Karp, Eric M [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Eaton, Todd R [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Sanchez i Nogue, Violeta [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Vorotnikov, Vassili [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Biddy, Mary J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Tan, Eric C [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Brandner, David [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Manker, Lorenz [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Michener, William E [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Vardon, Derek R [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Bratis, Adam D [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Liu, Rongming [University of Colorado; Gill, Ryan T. [University of Colorado; Gilhespy, Michelle [Johnson Matthey Technology Centre; Skoufa, Zinovia [Johnson Matthey Technology Centre; Watson, Michael J. [Johnson Matthey Technology Centre; Fruchey, O. Stanley [MATRIC; Cywar, Robin M. [Formerly NREL

    2017-12-08

    Acrylonitrile (ACN) is a petroleum-derived compound used in resins, polymers, acrylics, and carbon fiber. We present a process for renewable ACN production using 3-hydroxypropionic acid (3-HP), which can be produced microbially from sugars. The process achieves ACN molar yields exceeding 90% from ethyl 3-hydroxypropanoate (ethyl 3-HP) via dehydration and nitrilation with ammonia over an inexpensive titanium dioxide solid acid catalyst. We further describe an integrated process modeled at scale that is based on this chemistry and achieves near-quantitative ACN yields (98 +/- 2%) from ethyl acrylate. This endothermic approach eliminates runaway reaction hazards and achieves higher yields than the standard propylene ammoxidation process. Avoidance of hydrogen cyanide as a by-product also improves process safety and mitigates product handling requirements.

  5. Synthesis and characterization of nanophased silver tungstate

    Indian Academy of Sciences (India)

    nanoparticles were examined with scanning electron microscope (A Lieca Stereoscan. 440 model SEM) at an ... SEM image of rod-like nanocrystalline silver tungstate. Figure 3. ... Thermal analysis shows that the compound is thermally stable ...

  6. Lead-Tungstate Crystal of the ALICE Photon Spectrometer (PHOS)

    CERN Multimedia

    2003-01-01

    The photon spectrometer (PHOS) is designed to measure the temperature of collisions by detecting photons emerging from them. It will be made of lead tungstate crystals like these. When high-energy photons strike lead tungstate, they make it glow, or scintillate, and this glow can be measured. Lead tungstate is extremely dense (denser than iron), stopping most photons that reach it.

  7. Vanadate, molybdate and tungstate for orthomolecular medicine.

    Science.gov (United States)

    Matsumoto, J

    1994-09-01

    Recent studies indicate that oxyanions, such as vanadate (V) or vanadyl (IV), cause insulin-like effects on rats by stimulating the insulin receptor tyrosine kinase. Tungstate (VI) and molybdate (VI) show the same effects on rat adipocytes and hepatocytes. Results of uncontrolled trials on volunteers accumulated in Japan also suggest that tungstate effectively regulates diabetes mellitus without detectable side effects. Since these oxyanions naturally exist in organisms, oxyanion therapy, the oral administration of vanadate, vanadyl, molybdate, or tungstate, can be considered to be orthomolecular medicine. Therefore, these oxyanions may provide a viable alternative to chemotherapy. Many diseases in addition to diabetes mellitus might also be treated since the implication of these results is that tyrosine kinases are involved in a variety of diseases.

  8. Application prospects of cadmium-containing crystals based on tungstates and double tungstates

    CERN Document Server

    Nagornaya, L; Apanasenko, A; Tupitsyna, I; Chernikov, V; Vostretsov, V

    2002-01-01

    Tungstate and double tungstate crystals of high scintillation efficiency and detectors based on them are applied widely in the medical imaging and radiation monitoring because of their high sensitivity to the ionizing radiation, small radiation length, high radiation hardness, low afterglow level. In this work a possibility to broaden the application field of CWO crystals have been investigated by improvement of their spectrometric quality and decreasing of their afterglow level. CWO crystals with improved characteristics have been obtained (resolution for sup 1 sup 3 sup 7 Cs <8%, afterglow <0.02% after 20 ms). A possibility is considered to use these crystals for spectrometry of thermal and resonance neutrons, which is possible due to the presence of nuclei with large cross-section for these neutrons in the crystal lattice. Compounds of a new type based on Cd, La-containing double tungstates doped with rare earth elements have been synthesized, and their luminescent characteristics have been studied. ...

  9. Polymerization of lanthanide acrylonitrile complexes.

    Science.gov (United States)

    el-Mossalamy, El-Sayed H; Khalil, Ahmed A

    2002-01-01

    The molecular complexes of some lanthanides scandium (Sc3+), yttrium (Y3+), lanthanum (La3+), gadolinium (Gd3+), cerium (Ce3+) and ytterbium (Yb3) have been studies in dimethyl formamide (DMF) spectrophtometrically equilibrium constants (K), molar extintion coefficient (epsilon), energy of transition (E) and free energy (delta G*) were calculated. The polymerization of acrylonitrile has been studied and investigated in the presence of Sc3+, Y3+, La3+, Gd3+, Ce3+, and Yb3+ ions. The IR spectra of the formed AN-M (III) Br3 polymer complexes show the absence of the C identical to N band and the presence of two new bands corresponding to NH2 and OH groups. Magnetic moment values and the thermal stabilities of homopolymer and the polymer complexes were studied by means of thermogravimetric analysis and the activation energies for degradation were calculated.

  10. Biobased synthesis of acrylonitrile from glutamic acid

    NARCIS (Netherlands)

    Notre, le J.E.L.; Scott, E.L.; Franssen, M.C.R.; Sanders, J.P.M.

    2011-01-01

    Glutamic acid was transformed into acrylonitrile in a two step procedure involving an oxidative decarboxylation in water to 3-cyanopropanoic acid followed by a decarbonylation-elimination reaction using a palladium catalyst

  11. Synthesis, structure characterization and catalytic activity of nickel tungstate nanoparticles

    Science.gov (United States)

    Pourmortazavi, Seied Mahdi; Rahimi-Nasrabadi, Mehdi; Khalilian-Shalamzari, Morteza; Zahedi, Mir Mahdi; Hajimirsadeghi, Seiedeh Somayyeh; Omrani, Ismail

    2012-12-01

    Taguchi robust design was applied to optimize experimental parameters for controllable, simple and fast synthesis of nickel tungstate nanoparticles. NiWO4 nanoparticles were synthesized by precipitation reaction involving addition of nickel ion solution to the tungstate aqueous reagent and then formation of nickel tungstate nucleolus which are insoluble in aqueous media. Effects of various parameters such as nickel and tungstate concentrations, flow rate of reagent addition and reactor temperature on diameter of synthesized nickel tungstate nanoparticles were investigated experimentally by the aid of orthogonal array design. The results for analysis of variance (ANOVA) showed that particle size of nickel tungstate can be effectively tuned by controlling significant variables involving nickel and tungstate concentrations and flow rate; while, temperature of the reactor has a no considerable effect on the size of NiWO4 particles. The ANOVA results proposed the optimum conditions for synthesis of nickel tungstate nanoparticles via this technique. Also, under optimum condition nanoparticles of NiWO4 were prepared and their structure and chemical composition were characterized by means of EDAX, XRD, SEM, FT-IR spectroscopy, UV-vis spectroscopy, and photoluminescence. Finally, catalytic activity of the nanoparticles in a cycloaddition reaction was examined.

  12. Products of tungstate ion interaction with primary aliphatic amines

    International Nuclear Information System (INIS)

    Skrylev, L.D.; Sejfullina, I.I.; Purich, A.N.; Babinets, S.K.

    1982-01-01

    Using the methods of conductometric titration, IR-spectroscopic and thermographic analyses precipitates formed in the process of interaction of diluted aqueous solutions of sodium tungstate with alcoholic solutions of dodecyl-, tetradecyl- and octadecylamine have been studied. It is shown that as a result of interaction tungstates of corresponding amines are formed. The structure and thermal stability of singled out products are determined

  13. Synthesis, structure characterization and catalytic activity of nickel tungstate nanoparticles

    International Nuclear Information System (INIS)

    Pourmortazavi, Seied Mahdi; Rahimi-Nasrabadi, Mehdi; Khalilian-Shalamzari, Morteza; Zahedi, Mir Mahdi; Hajimirsadeghi, Seiedeh Somayyeh; Omrani, Ismail

    2012-01-01

    Graphical abstract: NiWO 4 nanoparticles were prepared via precipitation technique. Experimental parameters of procedure were optimized statistically. Highlights: ► NiWO 4 spherical nanoparticles were synthesized via direct precipitation method. ► Taguchi robust design was used for optimization of synthesis reaction parameters. ► Composition and structural properties of NiWO 4 nanoparticles were characterized. ► EDAX, XRD, SEM, FT-IR, UV–vis and photoluminescence techniques were employed. ► Catalytic activity of the product in a cyclo-addition reaction was investigated. - Abstract: Taguchi robust design was applied to optimize experimental parameters for controllable, simple and fast synthesis of nickel tungstate nanoparticles. NiWO 4 nanoparticles were synthesized by precipitation reaction involving addition of nickel ion solution to the tungstate aqueous reagent and then formation of nickel tungstate nucleolus which are insoluble in aqueous media. Effects of various parameters such as nickel and tungstate concentrations, flow rate of reagent addition and reactor temperature on diameter of synthesized nickel tungstate nanoparticles were investigated experimentally by the aid of orthogonal array design. The results for analysis of variance (ANOVA) showed that particle size of nickel tungstate can be effectively tuned by controlling significant variables involving nickel and tungstate concentrations and flow rate; while, temperature of the reactor has a no considerable effect on the size of NiWO 4 particles. The ANOVA results proposed the optimum conditions for synthesis of nickel tungstate nanoparticles via this technique. Also, under optimum condition nanoparticles of NiWO 4 were prepared and their structure and chemical composition were characterized by means of EDAX, XRD, SEM, FT-IR spectroscopy, UV–vis spectroscopy, and photoluminescence. Finally, catalytic activity of the nanoparticles in a cycloaddition reaction was examined.

  14. Synthesis, structure characterization and catalytic activity of nickel tungstate nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Pourmortazavi, Seied Mahdi, E-mail: pourmortazavi@yahoo.com [Faculty of Material and Manufacturing Technologies, Malek Ashtar University of Technology, Tehran (Iran, Islamic Republic of); Rahimi-Nasrabadi, Mehdi, E-mail: rahiminasrabadi@gmail.com [Department of Chemistry, Imam Hossein University, Tehran (Iran, Islamic Republic of); Khalilian-Shalamzari, Morteza [Department of Chemistry, Imam Hossein University, Tehran (Iran, Islamic Republic of); Zahedi, Mir Mahdi; Hajimirsadeghi, Seiedeh Somayyeh [Islamic Azad University, Varamin Pishva Branch, Varamin (Iran, Islamic Republic of); Omrani, Ismail [Department of Chemistry, Imam Hossein University, Tehran (Iran, Islamic Republic of)

    2012-12-15

    Graphical abstract: NiWO{sub 4} nanoparticles were prepared via precipitation technique. Experimental parameters of procedure were optimized statistically. Highlights: Black-Right-Pointing-Pointer NiWO{sub 4} spherical nanoparticles were synthesized via direct precipitation method. Black-Right-Pointing-Pointer Taguchi robust design was used for optimization of synthesis reaction parameters. Black-Right-Pointing-Pointer Composition and structural properties of NiWO{sub 4} nanoparticles were characterized. Black-Right-Pointing-Pointer EDAX, XRD, SEM, FT-IR, UV-vis and photoluminescence techniques were employed. Black-Right-Pointing-Pointer Catalytic activity of the product in a cyclo-addition reaction was investigated. - Abstract: Taguchi robust design was applied to optimize experimental parameters for controllable, simple and fast synthesis of nickel tungstate nanoparticles. NiWO{sub 4} nanoparticles were synthesized by precipitation reaction involving addition of nickel ion solution to the tungstate aqueous reagent and then formation of nickel tungstate nucleolus which are insoluble in aqueous media. Effects of various parameters such as nickel and tungstate concentrations, flow rate of reagent addition and reactor temperature on diameter of synthesized nickel tungstate nanoparticles were investigated experimentally by the aid of orthogonal array design. The results for analysis of variance (ANOVA) showed that particle size of nickel tungstate can be effectively tuned by controlling significant variables involving nickel and tungstate concentrations and flow rate; while, temperature of the reactor has a no considerable effect on the size of NiWO{sub 4} particles. The ANOVA results proposed the optimum conditions for synthesis of nickel tungstate nanoparticles via this technique. Also, under optimum condition nanoparticles of NiWO{sub 4} were prepared and their structure and chemical composition were characterized by means of EDAX, XRD, SEM, FT-IR spectroscopy, UV

  15. Radiation cured acrylonitrile--butadiene elastomers

    International Nuclear Information System (INIS)

    Eldred, R.J.

    1976-01-01

    In accordance with a preferred embodiment of this invention, the ultimate elongation of an electron beam radiation cured acrylonitrile-butadiene elastomer is significantly increased by the incorporation of a preferred noncrosslinking monomer, glycidyl methacrylate, in combination with the conventional crosslinking monomer, trimethylolpropanetrimethacrylate, prior to the radiation curing process

  16. Synthesis of cadmium tungstate films via sol-gel processing

    Energy Technology Data Exchange (ETDEWEB)

    Lennstrom, Kirk; Limmer, Steven J.; Cao Guozhong

    2003-06-23

    Cadmium tungstate is a scintillator material with excellent intrinsic photoluminescent properties. It is highly resistant to gamma radiation, has an almost non-existent afterglow and is highly efficient. Cadmium tungstate is also non-hydroscopic, unlike the more prevalent thallium-doped alkali halide scintillators. In order to create thin films of cadmium tungstate with precise stoichiometric control, a sol-gel processing technique has been applied to produce this material for the first time. In addition to lower processing temperatures, sol-gel-derived cadmium tungstate is cheaper and easier than other technologies, particularly for thin films. Furthermore, it has the potential to produce nanostructured materials with good optical quality. X-Ray diffraction results of sol-gel-derived materials fired at various temperatures imply crystallization of cadmium tungstate without the intermediate formation of either tungsten oxide or cadmium oxide. Scanning electron microscopy analysis shows the formation of nano-sized particles prior to heat treatment, which form meso-sized particles after the heat treatment. Photoluminesce analysis indicates emission of derived films at 480 nm, which agrees with other published data. Finally, the efficiency of derived films was approximately 6%{+-}1.8%.

  17. Highly phosphorescent hollow fibers inner-coated with tungstate nanocrystals

    Science.gov (United States)

    Ng, Pui Fai; Bai, Gongxun; Si, Liping; Lee, Ka I.; Hao, Jianhua; Xin, John H.; Fei, Bin

    2017-12-01

    In order to develop luminescent microtubes from natural fibers, a facile biomimetic mineralization method was designed to introduce the CaWO4-based nanocrystals into kapok lumens. The structure, composition, and luminescence properties of resultant fibers were investigated with microscopes, x-ray diffraction, thermogravimetric analysis, and fluorescence spectrometry. The yield of tungstate crystals inside kapok was significantly promoted with a process at high temperature and pressure—the hydrothermal treatment. The tungstate crystals grown on the inner wall of kapok fibers showed the same crystal structure with those naked powders, but smaller in crystal size. The resultant fiber assemblies demonstrated reduced phosphorescence intensity in comparison to the naked tungstate powders. However, the fibers gave more stable luminescence than the naked powders in wet condition. This approach explored the possibility of decorating natural fibers with high load of nanocrystals, hinting potential applications in anti-counterfeit labels, security textiles, and even flexible and soft optical devices.

  18. Synchrotron-based far-infrared spectroscopy of nickel tungstate

    International Nuclear Information System (INIS)

    Kalinko, A.; Kuzmin, A.; Roy, P.; Evarestov, R.A.

    2016-01-01

    Monoclinic antiferromagnetic NiWO 4 was studied by far-infrared (30-600 cm -1 ) absorption spectroscopy in the temperature range of 5-300 K using the synchrotron radiation from SOLEIL source. Two isomorphous CoWO 4 and ZnWO 4 tungstates were investigated for comparison. The phonon contributions in the far-infrared range of tungstates were interpreted using the first-principles spin-polarized linear combination of atomic orbital calculations. No contributions from magnetic excitations were found in NiWO 4 and CoWO 4 below their Neel temperatures down to 5 K.

  19. On surface reactions of iron tungstate with ethane

    International Nuclear Information System (INIS)

    Obrubov, V.A.; Shchukin, V.P.; Averbukh, A.Ya.

    1980-01-01

    Results of investigation of ethane oxidation reaction upon iron tungstate are presented. It is shown that catalytic oxidation of ethane is accompanied by the surface reaction of the catalyst reduction. Maximum reduction of surface depends upon temperature and considerably affects the direction of ethane oxidation process. Activation energies of ethane oxidation reactions and surface reaction of iron tungstate reduction depend on the surface actual state and at its reduction up to 5% from monolayer change in the limits 36.0-46.0 and 53.0-66.0 kcal/mol respectively

  20. Radiation induced graft copolymerization of acrylonitrile on natural rubber

    International Nuclear Information System (INIS)

    Claramma, N.M.; Mathew, N.M.; Thomas, E.V.

    1989-01-01

    Acrylonitrile graft natural rubber was prepared by initiating the polymerization of acrylonitrile in natural rubber field latex using γ-rays. The reaction was carried out at different rubber-monomer concentrations and the properties of the modified rubbers were compared with those of natural rubber and nitrile rubber. (author)

  1. [Migrants from disposable gloves and residual acrylonitrile].

    Science.gov (United States)

    Wakui, C; Kawamura, Y; Maitani, T

    2001-10-01

    Disposable gloves made from polyvinyl chloride with and without di(2-ethylhexyl) phthalate (PVC-DEHP, PVC-NP), polyethylene (PE), natural rubber (NR) and nitrile-butadiene rubber (NBR) were investigated with respect to evaporation residue, migrated metals, migrants and residual acrylonitrile. The evaporation residue found in n-heptane was 870-1,300 ppm from PVC-DEHP and PVC-NP, which was due to the plasticizers. Most of the PE gloves had low evaporation residue levels and migrants, except for the glove designated as antibacterial, which released copper and zinc into 4% acetic acid. For the NR and NBR gloves, the evaporation residue found in 4% acetic acid was 29-180 ppm. They also released over 10 ppm of calcium and 6 ppm of zinc into 4% acetic acid, and 1.68-8.37 ppm of zinc di-ethyldithiocarbamate and zinc di-n-butyldithiocarbamate used as vulcanization accelerators into n-heptane. The acrylonitrile content was 0.40-0.94 ppm in NBR gloves.

  2. Transport kinetics of hydrogen permeable lanthanum tungstate

    Energy Technology Data Exchange (ETDEWEB)

    Falkenstein, Andreas

    2017-01-24

    The electrical conductivity relaxation technique is a widely used method to determine the oxygen transport parameters of mixed ionic-electronic conductors. In recent years, it has been modified to investigate the hydration behavior of proton conducting mixed conductors, giving access to up to four transport parameters in a single relaxation experiment, the diffusion coefficients and surface reaction rates of hydrogen and oxygen. In this work, the transport properties of the fluorite type protonic conductor lanthanum tungstate have been investigated by means of electrical conductivity relaxation. The experiments were performed in a temperature range from 650 C to 950 C, in a pO{sub 2} range from 3 mbar to 100 mbar and in a pH{sub 2}O range from 10 mbar to 100 mbar and in dry atmosphere. At high temperatures, the conductivity relaxation curve follows the expected two-fold non-monotonic behavior upon hydration. At low temperatures, however, the contribution of the fast hydrogen kinetic decreases and by a further decrease of the temperature, the relaxation shows two-fold monotonic behavior. The power factors - the contribution of each single fold relaxation curve to the resulting two-fold relaxation curve, which is a superposition - have been derived to explain the behavior mentioned above. The activation energy of the oxygen incorporation is rather low. Hence, oxidation experiments were performed in dry atmospheres in order to investigate if the origin of the oxygen species is relevant. The results revealed higher activation energies, which was expected, but also higher absolute values of the surface reaction rate and the diffusion coefficient. Oxidation experiments with increasing humidity revealed that the increased diffusivity cannot be attributed to the total concentrations of electron holes and proton interstitials. First experiments using spectroscopic relaxation, which is dependent on the concentration of hydroxy-anions only, were performed. Absorption bands

  3. Review of health risks in acrylonitrile industry

    Energy Technology Data Exchange (ETDEWEB)

    Guirguis, S S; Cohen, M B; Rajhans, G S

    1984-05-01

    The Occupational Health Branch of the Ontario Ministry of Labour began a study in 1978 for the evaluation of health risks associated with acrylonitrile (AN) exposure. Detailed hygiene and medical investigations were conducted in fourteen plants for evaluating AN exposure in various industrial processes. For companies were also studied in relation to mixed chemical exposure representing acrylic fibres, nitrile rubber, ABS-resin, and acrylic emulsions production. The possible interaction between AN and other coexisting chemical exposures was reviewed since dimethyl formamide, styrene, and butadiene have similar pharmacokinetics and possible synergistic effects. Exposure in acrylic fibre production may be synergistic and carcinogenic. Results of air monitoring indicated exposure levels to AN below 2 ppm (TWA) in most cases. Exposure to other co-existing chemicals was evaluated. Results of medical tests indicated no significant abnormalities in chest x-rays or liver function tests in currently exposed workers.

  4. Measurement of the Muon Stopping Power in Lead Tungstate

    CERN Document Server

    Chatrchyan, S; Sirunyan, A M; Adam, W; Arnold, B; Bergauer, H; Bergauer, T; Dragicevic, M; Eichberger, M; Erö, J; Friedl, M; Frühwirth, R; Ghete, V M; Hammer, J; Hänsel, S; Hoch, M; Hörmann, N; Hrubec, J; Jeitler, M; Kasieczka, G; Kastner, K; Krammer, M; Liko, D; Magrans de Abril, I; Mikulec, I; Mittermayr, F; Neuherz, B; Oberegger, M; Padrta, M; Pernicka, M; Rohringer, H; Schmid, S; Schöfbeck, R; Schreiner, T; Stark, R; Steininger, H; Strauss, J; Taurok, A; Teischinger, F; Themel, T; Uhl, D; Wagner, P; Waltenberger, W; Walzel, G; Widl, E; Wulz, C E; Chekhovsky, V; Dvornikov, O; Emeliantchik, I; Litomin, A; Makarenko, V; Marfin, I; Mossolov, V; Shumeiko, N; Solin, A; Stefanovitch, R; Suarez Gonzalez, J; Tikhonov, A; Fedorov, A; Karneyeu, A; Korzhik, M; Panov, V; Zuyeuski, R; Kuchinsky, P; Beaumont, W; Benucci, L; Cardaci, M; De Wolf, E A; Delmeire, E; Druzhkin, D; Hashemi, M; Janssen, X; Maes, T; Mucibello, L; Ochesanu, S; Rougny, R; Selvaggi, M; Van Haevermaet, H; Van Mechelen, P; Van Remortel, N; Adler, V; Beauceron, S; Blyweert, S; D'Hondt, J; De Weirdt, S; Devroede, O; Heyninck, J; Kalogeropoulos, A; Maes, J; Maes, M; Mozer, M U; Tavernier, S; Van Doninck, W; Van Mulders, P; Villella, I; Bouhali, O; Chabert, E C; Charaf, O; Clerbaux, B; De Lentdecker, G; Dero, V; Elgammal, S; Gay, A P R; Hammad, G H; Marage, P E; Rugovac, S; Vander Velde, C; Vanlaer, P; Wickens, J; Grunewald, M; Klein, B; Marinov, A; Ryckbosch, D; Thyssen, F; Tytgat, M; Vanelderen, L; Verwilligen, P; Basegmez, S; Bruno, G; Caudron, J; Delaere, C; Demin, P; Favart, D; Giammanco, A; Grégoire, G; Lemaitre, V; Militaru, O; Ovyn, S; Piotrzkowski, K; Quertenmont, L; Schul, N; Beliy, N; Daubie, E; Alves, G A; Pol, M E; Souza, M H G; Carvalho, W; De Jesus Damiao, D; De Oliveira Martins, C; Fonseca De Souza, S; Mundim, L; Oguri, V; Santoro, A; Silva Do Amaral, S M; Sznajder, A; Fernandez Perez Tomei, T R; Ferreira Dias, M A; Gregores, E M; Novaes, S F; Abadjiev, K; Anguelov, T; Damgov, J; Darmenov, N; 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Ryan, M J; Seez, C; Sharp, P; Sidiropoulos, G; Stettler, M; Stoye, M; Takahashi, M; Tapper, A; Timlin, C; Tourneur, S; Vazquez Acosta, M; Virdee, T; Wakefield, S; Wardrope, D; Whyntie, T; Wingham, M; Cole, J E; Goitom, I; Hobson, P R; Khan, A; Kyberd, P; Leslie, D; Munro, C; Reid, I D; Siamitros, C; Taylor, R; Teodorescu, L; Yaselli, I; Bose, T; Carleton, M; Hazen, E; Heering, A H; Heister, A; John, J St; Lawson, P; Lazic, D; Osborne, D; Rohlf, J; Sulak, L; Wu, S; Andrea, J; Avetisyan, A; Bhattacharya, S; Chou, J P; Cutts, D; Esen, S; Kukartsev, G; Landsberg, G; Narain, M; Nguyen, D; Speer, T; Tsang, K V; Breedon, R; Calderon De La Barca Sanchez, M; Case, M; Cebra, D; Chertok, M; Conway, J; Cox, P T; Dolen, J; Erbacher, R; Friis, E; Ko, W; Kopecky, A; Lander, R; Lister, A; Liu, H; Maruyama, S; Miceli, T; Nikolic, M; Pellett, D; Robles, J; Searle, M; Smith, J; Squires, M; Stilley, J; Tripathi, M; Vasquez Sierra, R; Veelken, C; Andreev, V; Arisaka, K; Cline, D; Cousins, R; Erhan, S; Hauser, J; Ignatenko, M; Jarvis, C; Mumford, J; Plager, C; Rakness, G; Schlein, P; Tucker, J; Valuev, V; Wallny, R; Yang, X; Babb, J; Bose, M; Chandra, A; Clare, R; Ellison, J A; Gary, J W; Hanson, G; Jeng, G Y; Kao, S C; Liu, F; Liu, H; Luthra, A; Nguyen, H; Pasztor, G; Satpathy, A; Shen, B C; Stringer, R; Sturdy, J; Sytnik, V; Wilken, R; Wimpenny, S; Branson, J G; Dusinberre, E; Evans, D; Golf, F; Kelley, R; Lebourgeois, M; Letts, J; Lipeles, E; Mangano, B; Muelmenstaedt, J; Norman, M; Padhi, S; Petrucci, A; Pi, H; Pieri, M; Ranieri, R; Sani, M; Sharma, V; Simon, S; Würthwein, F; Yagil, A; Campagnari, C; D'Alfonso, M; Danielson, T; Garberson, J; Incandela, J; Justus, C; Kalavase, P; Koay, S A; Kovalskyi, D; Krutelyov, V; Lamb, J; Lowette, S; Pavlunin, V; Rebassoo, F; Ribnik, J; Richman, J; Rossin, R; Stuart, D; To, W; Vlimant, J R; Witherell, M; Apresyan, A; Bornheim, A; Bunn, J; Chiorboli, M; Gataullin, M; Kcira, D; Litvine, V; Ma, Y; Newman, H B; Rogan, C; Timciuc, V; Veverka, J; Wilkinson, R; Yang, Y; Zhang, L; Zhu, K; Zhu, R Y; Akgun, B; Carroll, R; Ferguson, T; Jang, D W; Jun, S Y; Paulini, M; Russ, J; Terentyev, N; Vogel, H; Vorobiev, I; Cumalat, J P; Dinardo, M E; Drell, B R; Ford, W T; Heyburn, B; Luiggi Lopez, E; Nauenberg, U; Stenson, K; Ulmer, K; Wagner, S R; Zang, S L; Agostino, L; Alexander, J; Blekman, F; Cassel, D; Chatterjee, A; Das, S; Gibbons, L K; Heltsley, B; Hopkins, W; Khukhunaishvili, A; Kreis, B; Kuznetsov, V; Patterson, J R; Puigh, D; Ryd, A; Shi, X; Stroiney, S; Sun, W; Teo, W D; Thom, J; Vaughan, J; Weng, Y; Wittich, P; Beetz, C P; Cirino, G; Sanzeni, C; Winn, D; Abdullin, S; Afaq, M A; Albrow, M; Ananthan, B; Apollinari, G; Atac, M; Badgett, W; Bagby, L; Bakken, J A; Baldin, B; Banerjee, S; Banicz, K; Bauerdick, L A T; Beretvas, A; Berryhill, J; Bhat, P C; Biery, K; Binkley, M; Bloch, I; Borcherding, F; Brett, A M; Burkett, K; Butler, J N; Chetluru, V; Cheung, H W K; Chlebana, F; Churin, I; Cihangir, S; Crawford, M; Dagenhart, W; Demarteau, M; Derylo, G; Dykstra, D; Eartly, D P; Elias, J E; Elvira, V D; Evans, D; Feng, L; Fischler, M; Fisk, I; Foulkes, S; Freeman, J; Gartung, P; Gottschalk, E; Grassi, T; Green, D; Guo, Y; Gutsche, O; Hahn, A; Hanlon, J; Harris, R M; Holzman, B; Howell, J; Hufnagel, D; James, E; Jensen, H; Johnson, M; Jones, C D; Joshi, U; Juska, E; Kaiser, J; Klima, B; Kossiakov, S; Kousouris, K; Kwan, S; Lei, C M; Limon, P; Lopez Perez, J A; Los, S; Lueking, L; Lukhanin, G; Lusin, S; Lykken, J; Maeshima, K; Marraffino, J M; Mason, D; McBride, P; Miao, T; Mishra, K; Moccia, S; Mommsen, R; Mrenna, S; Muhammad, A S; Newman-Holmes, C; Noeding, C; O'Dell, V; Prokofyev, O; Rivera, R; Rivetta, C H; Ronzhin, A; Rossman, P; Ryu, S; Sekhri, V; Sexton-Kennedy, E; Sfiligoi, I; Sharma, S; Shaw, T M; Shpakov, D; Skup, E; Smith, R P; Soha, A; Spalding, W J; Spiegel, L; Suzuki, I; Tan, P; Tanenbaum, W; Tkaczyk, S; Trentadue, R; Uplegger, L; Vaandering, E W; Vidal, R; Whitmore, J; Wicklund, E; Wu, W; Yarba, J; Yumiceva, F; Yun, J C; Acosta, D; Avery, P; Barashko, V; Bourilkov, D; Chen, M; Di Giovanni, G P; Dobur, D; Drozdetskiy, A; Field, R D; Fu, Y; Furic, I K; Gartner, J; Holmes, D; Kim, B; Klimenko, S; Konigsberg, J; Korytov, A; Kotov, K; Kropivnitskaya, A; Kypreos, T; Madorsky, A; Matchev, K; Mitselmakher, G; Pakhotin, Y; Piedra Gomez, J; Prescott, C; Rapsevicius, V; Remington, R; Schmitt, M; Scurlock, B; Wang, D; Yelton, J; Ceron, C; Gaultney, V; Kramer, L; Lebolo, L M; Linn, S; Markowitz, P; Martinez, G; Rodriguez, J L; Adams, T; Askew, A; Baer, H; Bertoldi, M; Chen, J; Dharmaratna, W G D; Gleyzer, S V; Haas, J; Hagopian, S; Hagopian, V; Jenkins, M; Johnson, K F; Prettner, E; Prosper, H; Sekmen, S; Baarmand, M M; Guragain, S; Hohlmann, M; Kalakhety, H; Mermerkaya, H; Ralich, R; Vodopiyanov, I; Abelev, B; Adams, M R; Anghel, I M; Apanasevich, L; Bazterra, V E; Betts, R R; Callner, J; Castro, M A; Cavanaugh, R; Dragoiu, C; Garcia-Solis, E J; Gerber, C E; Hofman, D J; Khalatian, S; Mironov, C; Shabalina, E; Smoron, A; Varelas, N; Akgun, U; Albayrak, E A; Ayan, A S; Bilki, B; Briggs, R; Cankocak, K; Chung, K; Clarida, W; Debbins, P; Duru, F; Ingram, F D; Lae, C K; McCliment, E; Merlo, J P; Mestvirishvili, A; Miller, M J; Moeller, A; Nachtman, J; Newsom, C R; Norbeck, E; Olson, J; Onel, Y; Ozok, F; Parsons, J; Schmidt, I; Sen, S; Wetzel, J; Yetkin, T; Yi, K; Barnett, B A; Blumenfeld, B; Bonato, A; Chien, C Y; Fehling, D; Giurgiu, G; Gritsan, A V; Guo, Z J; Maksimovic, P; Rappoccio, S; Swartz, M; Tran, N V; Zhang, Y; Baringer, P; Bean, A; Grachov, O; Murray, M; Radicci, V; Sanders, S; Wood, J S; Zhukova, V; Bandurin, D; Bolton, T; Kaadze, K; Liu, A; Maravin, Y; Onoprienko, D; Svintradze, I; Wan, Z; Gronberg, J; Hollar, J; Lange, D; Wright, D; Baden, D; Bard, R; Boutemeur, M; Eno, S C; Ferencek, D; Hadley, N J; Kellogg, R G; Kirn, M; Kunori, S; Rossato, K; Rumerio, P; Santanastasio, F; Skuja, A; Temple, J; Tonjes, M B; Tonwar, S C; Toole, T; Twedt, E; Alver, B; Bauer, G; Bendavid, J; Busza, W; Butz, E; Cali, I A; Chan, M; D'Enterria, D; Everaerts, P; Gomez Ceballos, G; Hahn, K A; Harris, P; Jaditz, S; Kim, Y; Klute, M; Lee, Y J; Li, W; Loizides, C; Ma, T; Miller, M; Nahn, S; Paus, C; Roland, C; Roland, G; Rudolph, M; Stephans, G; Sumorok, K; Sung, K; Vaurynovich, S; Wenger, E A; Wyslouch, B; Xie, S; Yilmaz, Y; Yoon, A S; Bailleux, D; Cooper, S I; Cushman, P; Dahmes, B; De Benedetti, A; Dolgopolov, A; Dudero, P R; Egeland, R; Franzoni, G; Haupt, J; Inyakin, A; Klapoetke, K; Kubota, Y; Mans, J; Mirman, N; Petyt, D; Rekovic, V; Rusack, R; Schroeder, M; Singovsky, A; Zhang, J; Cremaldi, L M; Godang, R; Kroeger, R; Perera, L; Rahmat, R; Sanders, D A; Sonnek, P; Summers, D; Bloom, K; Bockelman, B; Bose, S; Butt, J; Claes, D R; Dominguez, A; Eads, M; Keller, J; Kelly, T; Kravchenko, I; Lazo-Flores, J; Lundstedt, C; Malbouisson, H; Malik, S; Snow, G R; Baur, U; Iashvili, I; Kharchilava, A; Kumar, A; Smith, K; Strang, M; Alverson, G; Barberis, E; Boeriu, O; Eulisse, G; Govi, G; McCauley, T; Musienko, Y; Muzaffar, S; Osborne, I; Paul, T; Reucroft, S; Swain, J; Taylor, L; Tuura, L; Anastassov, A; Gobbi, B; Kubik, A; Ofierzynski, R A; Pozdnyakov, A; Schmitt, M; Stoynev, S; Velasco, M; Won, S; Antonelli, L; Berry, D; Hildreth, M; Jessop, C; Karmgard, D J; Kolberg, T; Lannon, K; Lynch, S; Marinelli, N; Morse, D M; Ruchti, R; Slaunwhite, J; Warchol, J; Wayne, M; Bylsma, B; Durkin, L S; Gilmore, J; Gu, J; Killewald, P; Ling, T Y; Williams, G; Adam, N; Berry, E; Elmer, P; Garmash, A; Gerbaudo, D; Halyo, V; Hunt, A; Jones, J; Laird, E; Marlow, D; Medvedeva, T; Mooney, M; Olsen, J; Piroué, P; Stickland, D; Tully, C; Werner, J S; Wildish, T; Xie, Z; Zuranski, A; Acosta, J G; Bonnett Del Alamo, M; Huang, X T; Lopez, A; Mendez, H; Oliveros, S; Ramirez Vargas, J E; Santacruz, N; Zatzerklyany, A; Alagoz, E; Antillon, E; Barnes, V E; Bolla, G; Bortoletto, D; Everett, A; Garfinkel, A F; Gecse, Z; Gutay, L; Ippolito, N; Jones, M; Koybasi, O; Laasanen, A T; Leonardo, N; Liu, C; Maroussov, V; Merkel, P; Miller, D H; Neumeister, N; Sedov, A; Shipsey, I; Yoo, H D; Zheng, Y; Jindal, P; Parashar, N; Cuplov, V; Ecklund, K M; Geurts, F J M; Liu, J H; Maronde, D; Matveev, M; Padley, B P; Redjimi, R; Roberts, J; Sabbatini, L; Tumanov, A; Betchart, B; Bodek, A; Budd, H; Chung, Y S; de Barbaro, P; Demina, R; Flacher, H; Gotra, Y; Harel, A; Korjenevski, S; Miner, D C; Orbaker, D; Petrillo, G; Vishnevskiy, D; Zielinski, M; Bhatti, A; Demortier, L; Goulianos, K; Hatakeyama, K; Lungu, G; Mesropian, C; Yan, M; Atramentov, O; Bartz, E; Gershtein, Y; Halkiadakis, E; Hits, D; Lath, A; Rose, K; Schnetzer, S; Somalwar, S; Stone, R; Thomas, S; Watts, T L; Cerizza, G; Hollingsworth, M; Spanier, S; Yang, Z C; York, A; Asaadi, J; Aurisano, A; Eusebi, R; Golyash, A; Gurrola, A; Kamon, T; Nguyen, C N; Pivarski, J; Safonov, A; Sengupta, S; Toback, D; Weinberger, M; Akchurin, N; Berntzon, L; Gumus, K; Jeong, C; Kim, H; Lee, S W; Popescu, S; Roh, Y; Sill, A; Volobouev, I; Washington, E; Wigmans, R; Yazgan, E; Engh, D; Florez, C; Johns, W; Pathak, S; Sheldon, P; Andelin, D; Arenton, M W; Balazs, M; Boutle, S; Buehler, M; Conetti, S; Cox, B; Hirosky, R; Ledovskoy, A; Neu, C; Phillips II, D; Ronquest, M; Yohay, R; Gollapinni, S; Gunthoti, K; Harr, R; Karchin, P E; Mattson, M; Sakharov, A; Anderson, M; Bachtis, M; Bellinger, J N; Carlsmith, D; Crotty, I; Dasu, S; Dutta, S; Efron, J; Feyzi, F; Flood, K; Gray, L; Grogg, K S; Grothe, M; Hall-Wilton, R; Jaworski, M; Klabbers, P; Klukas, J; Lanaro, A; Lazaridis, C; Leonard, J; Loveless, R; Magrans de Abril, M; Mohapatra, A; Ott, G; Polese, G; Reeder, D; Savin, A; Smith, W H; Sourkov, A; Swanson, J; Weinberg, M; Wenman, D; Wensveen, M; White, A

    2010-01-01

    A large sample of cosmic ray events collected by the CMS detector is exploited to measure the specific energy loss of muons in the lead tungstate of the electromagnetic calorimeter. The measurement spans a momentum range from 5 GeV/c to 1 TeV/c. The results are consistent with the expectations over the entire range. The calorimeter energy scale, set with 120 GeV/c electrons, is validated down to the sub-GeV region using energy deposits, of order 100 MeV, associated with low-momentum muons. The muon critical energy in lead tungstate is measured to be 160+5/-6 plus or minus 8 GeV, in agreement with expectations. This is the first experimental determination of muon critical energy.

  5. Lead tungstate crystal of the ALICE Photon Spectrometer (PHOS)

    CERN Document Server

    Patrice Loïez

    2002-01-01

    A consignment of 500 lead tungstate crystals arrived at CERN from the northern Russian town of Apatity in May. Destined for the ALICE heavy-ion experiment in preparation for the Large Hadron Collider, each crystal is an 18 cm long rod with a 2.2 cm square section, and weighs some 750 g. A total of 17 000 crystals will make up the experiment's photon spectrometer.

  6. Dual-Readout Calorimetry with Lead Tungstate Crystals

    OpenAIRE

    Akchurin, N.

    2007-01-01

    Results are presented of beam tests in which a small electromagnetic calorimeter consisting of lead tungstate crystals was exposed to 50 GeV electrons and pions. This calorimeter was backed up by the DREAM Dual-Readout calorimeter, which measures the scintillation and \\v{C}erenkov light produced in the shower development, using two different media. The signals from the crystal calorimeter were analyzed in great detail in an attempt to determine the contributions from these two types of light ...

  7. Effect of acrylonitrile on the electrode processes ivolving copper cations

    Directory of Open Access Journals (Sweden)

    Viktor F. Vargalyuk

    2016-03-01

    Full Text Available Based on the results of cyclic voltammetry and study of deposits morphology, it has been shown that acrylonitrile does not have significant effect on the mechanism of Cu2+ + 2ē → Cu0 reaction. This distinguishes acrylonitrile from the unsaturated polyfunctional organic substances (acrylic acid, acrylamide which forms stable complexes with Cu2+ ions. Acrylonitrile just inhibits cathodic process by adsorbing on the surface of electrode thus blocking its active sites. But the presence of acrylonitrile significantly changes the mechanism of the anodic process. It has been found that acrylonitrile interacts with surface copper atoms thus forming thermodynamically stable [Cu π-AN]0 π‑complexes. Ionization potential of these π‑complexes is more negative if compare to copper atoms. As the result acceleration of anodic process takes place in the low polarization area. However, since the chemisorption is a slow process the presence of acrylonitrile mainly affects dissolution of the first surface layers of copper atoms. Further ionization of copper atoms runs out directly and requires higher polarization.

  8. Seven up. The incorporation of Li{sup +} cations in yttrium tungstate and silicate tungstate

    Energy Technology Data Exchange (ETDEWEB)

    Dorn, Katharina V.; Schustereit, Tanja; Strobel, Sabine; Hartenbach, Ingo [Institute for Inorganic Chemistry, University of Stuttgart (Germany)

    2017-12-13

    Lithium yttrium(III) oxidotungstate(VI), LiY{sub 5}W{sub 8}O{sub 32}, was synthesized by solid-state reaction of a mixture of lithium chloride, yttrium sesquioxide, and tungsten trioxide. It crystallizes monoclinically in space group C2/c (a = 1908.34(5) pm, b = 561.80(1) pm, c = 1147.22(3) pm, β = 111.255(2) , Z = 2). The structure comprises one mixed Li{sup +}/Y{sup 3+} cationic position (molar ratio Li:Y1 = 1:1) and one cationic position exclusively occupied by Y{sup 3+} cations. All W{sup 6+} cations are surrounded by six O{sup 2-} anions, forming distorted octahedral coordination polyhedra, which are mutually linked by both edges and vertices to cascaded {sup 2}{sub ∞}{[W_4O_1_6]"8"-} layers. Lithium yttrium(III) oxidosilicate(IV) oxidotungstate(VI), LiY{sub 5}[SiO{sub 4}]{sub 2}[WO{sub 4}]{sub 4}, was obtained as by-product in the synthesis of YF[WO{sub 4}] by sintering a mixture of Y{sub 2}O{sub 3}, YF{sub 3}, and WO{sub 3} with lithium chloride as fluxing agent in sealed silica ampoules. It crystallizes orthorhombically in space group Pban (a = 512.08(4) pm, b = 1673.35(12) pm, c = 493.68(4) pm, Z = 1) bearing one mixed crystallographic position occupied by Li{sup +} and Y{sup 3+} cations in a molar ratio of 1:3 and one exclusive Y{sup 3+} position in its structure. The coordination polyhedra around the Si{sup 4+} and W{sup 6+} cations are isolated tetrahedra built up by four O{sup 2-} anions each. The crystal structure of this silicate tungstate can be derived from the scheelite-type structure by inserting anionic {sup 2}{sub ∞}{(Y2[SiO_4])"-} layers between cationic {sup 2}{sub ∞}{[(Li/Y1)_2[WO_4]_2]"+} double layers. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  9. Testing the radiation hardness of lead tungstate scintillating crystals

    CERN Document Server

    Shao, M; Li Chuan; Chen, H; Xu, Z Z; Wang, Z M

    2000-01-01

    Large Hadron Collider operation will produce a high radiation background. PbWO/sub 4/ crystals are selected as scintillators for the CMS electromagnetic calorimeter. To reach the precise requirement for energy measurements, a strict requirement for the radiation hardness is needed. In this paper, we present a method for evaluating the radiation hardness and its measurement. Results for several full size (23 cm length) lead tungstate crystals under Co/sup 60/ gamma - ray irradiation are given, investigating the light yield loss and its longitudinal uniformity. (8 refs).

  10. High performance lignin-acrylonitrile polymer blend materials

    Energy Technology Data Exchange (ETDEWEB)

    Naskar, Amit K.; Tran, Chau D.

    2017-11-14

    A polymer blend material comprising: (i) a lignin component having a weight-average molecular weight of up to 1,000,000 g/mol; and (ii) an acrylonitrile-containing copolymer rubber component comprising acrylonitrile units in combination with diene monomer units, and having an acrylonitrile content of at least 20 mol %; wherein said lignin component is present in an amount of at least 5 wt % and up to about 95 wt % by total weight of components (i) and (ii); and said polymer blend material possesses a tensile yield stress of at least 5 MPa, or a tensile stress of at least 5 MPa at 10% elongation, or a tensile stress of at least 5 MPa at 100% elongation. Methods for producing the polymer blend, molded forms thereof, and articles thereof, are also described.

  11. Double tungstates of metals of scandium and ammonium subgroups

    Energy Technology Data Exchange (ETDEWEB)

    Maksin, V I [AN Ukrainskoj SSR, Kiev. Inst. Kolloidnoj Khimii i Khimii Vody

    1980-06-01

    The methods of pH-potentiometry, conductometry, determination of residual concentrations of liquid phases and precipitations, selected by chemical analysis have been used for investigation R(NO/sub 3/)/sub 3/-(NH/sub 4/)/sub 2/WO/sub 2/-H/sub 2/O systems, (where R=Sc, Y, La). The formation of double tungstates NH/sub 4/R(WO/sub 4/)/sub 2/xnH/sub 2/O is established. The NH/sub 4/Sc(WO/sub 4/)/sub 2/x4.5H/sub 2/O, NH/sub 4/Yx(WO/sub 4/)/sub 2/x3H/sub 2/O, NH/sub 4/La(WO/sub 4/)/sub 2/x1.5H/sub 2/O compounds are synthesized in individual form. Precipitation conditions (pH, concentration ratio) and composition of the solid phase are determined. The behaviour of synthesized slats at thermolysis up to 880 deg C is studied. Physicochemical properties (color, solubility of the simple and double tungstates of scandium, yttrium and lanthanum with ammonium) is studied. IR spectra and X-ray diffraction analysis give idea about double salts structural transformations.

  12. Tungstate adsorption onto Italian soils with different characteristics.

    Science.gov (United States)

    Petruzzelli, Gianniantonio; Pedron, Francesca

    2017-08-01

    The study of tungsten in the environment is currently of considerable interest because of the growing concerns resulting from its possible toxicity and carcinogenicity. Adsorption reactions are some of the fundamental processes governing the fate and transport of tungsten compounds in soil. This paper reports data on the adsorption of tungstate ions in three different Italian soils, which are characteristic of the Mediterranean region. The results show that pH is the most important factor governing the adsorption of tungstate in these soils. The data interpreted according to the Langmuir equation show that the maximum value of adsorption is approximately 30 mmol kg -1 for the most acidic soil (pH = 4.50) and approximately 9 mmol kg -1 for the most basic soil (pH = 7.40). In addition, soil organic matter is shown to play a fundamental role in adsorption processes, which are favored in soils with a higher organic matter content. The data could contribute to a better understanding of the behavior of tungsten compounds in Italian soils for which current knowledge is very scarce, also in view of environmental regulations, which are currently lacking.

  13. Interaction of cadmium and indium nitrate mixture with sodium tungstate in aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Belousova, E E; Krivobok, V I; Gruba, A I [Donetskij Gosudarstvennyj Univ. (Ukrainian SSR)

    1982-01-01

    The interaction of the mixture of cadmium and indium nitrates with sodium tungstate in aqueous solution is studied using the methods of ''residual concentrations'', pH potentiometry and conductometry. Independent of the ratio of components in the initial solution a mixture of coprecipitated normal tungstates of cadmium and indium is formed in the system. Heat treatment of the precipitates at 800 deg C for 50 hrs with subsequent hardening results in the formation of solid solutions on the basis of normal cadmium and indium tungstates.

  14. Polyacrylamide polymers derived from acrylonitrile without intermediate isolation

    Energy Technology Data Exchange (ETDEWEB)

    Norton, C.J.; Falk, D.O.

    1977-04-05

    Hydrolyzed and neutralized acrylonitrile is polymerized in solution without isolation to produce a high molecular weight polyacrylamide useful for mobility control in secondary recovery of petroleum. The polyacrylamide optionally may be hydrolyzed, methylolated, and sulfomethylated to further enhance its water-thickening properties. This procedure reduces the cost of making polyacrylamide. (5 claims)

  15. 21 CFR 181.32 - Acrylonitrile copolymers and resins.

    Science.gov (United States)

    2010-04-01

    .../styrene copolymer—for use only as piping for handling food products and for repeated-use articles intended... acrylonitrile monomer extraction for finished food-contact articles, determined by using the method of analysis... from the Center for Food Safety and Applied Nutrition (HFS-200), Food and Drug Administration, 5100...

  16. Performance of an electromagnetic calorimeter with lead-tungstate crystals

    International Nuclear Information System (INIS)

    Kohara, R.; Sugitate, T.; Sugita, N.; Tsuchimoto, Y.; Toyoda, D.; Homma, K.; Yamazaki, H.

    2003-01-01

    The performance of an electromagnetic calorimeter with lead-tungstate (PWO) crystals was tested by using 1 GeV photons. The calorimeter consisted of nine crystals of 20 x 20 x 200 mm in size arranged in a 3 x 3 array. The energy resolution was obtained to be σ E /E = (2.50 ± 0.75%) / √E + (1.25 ± 0.34%) with a photomultiplier tube (PMT) reading all signals. Another setup, reading the central cell with an avalanche photo diode (APD) and the surrounding 8 cells with the PMT, was also studied, however, its energy resolution was not scaled with the stochastic function and we found the resolution of about 10% around 1 GeV. (author)

  17. Luminescence spectra of lead tungstate, spodumene and topaz crystals

    International Nuclear Information System (INIS)

    Ramachandran, Vasuki

    2002-01-01

    A detailed set of thermoluminescence, cathodoluminescence and radioluminescence (TL, CLTL and RLTL) data of lead tungstate, Spodumene and Topaz have been reported for the first time over a wide temperature range from 25 to 500K. Lead tungstate (PbWO 4 ), a widely known scintillating material, gives TL glow peaks which are related to complex defect centres. Doping of this crystal with trivalent rare earth ions (La 3+ , Y 3+ ) reduces the slow component of the emission thereby making it more suitable for its applications. The pentavalent dopants on the other hand, enhance the green emission and quench the blue emission at temperatures 100K. The origin and the irradiation temperature definitely have an effect on the spectrum. No strong relationship could be derived from the dose dependence data. Two less studied minerals, Spodumene and Topaz have also been investigated with the luminescence techniques. The glow peak near 250degC is thought to have originated from Mn 2+ centres. As there are no ESR data available, the assignment of defect centres is rather difficult. Cr + acts as the quencher in green spodumene. Topaz had the same treatment as the other two sets of samples and the defect centre characterisation looks complex as each coloured sample gave different patterns of glow peaks. Cathodoluminescence whilst heating (CLTL) of all these samples showed some unusual features in the form of a luminescence intensity step which is believed to have originated from the presence of ice. Water, in nanoparticle size quantities, is present as a contaminant in the lattice and undergoes a phase transition at 170K from hexagonal to cubic structures. This phase change influences the luminescence efficiency of the host material and is reflected in the spectrum as a discontinuity in intensity. (author)

  18. Phosphorylation events implicating p38 and PI3K mediate tungstate-effects in MIN6 beta cells

    International Nuclear Information System (INIS)

    Piquer, Sandra; Barcelo-Batllori, Silvia; Julia, Marta; Marzo, Nuria; Nadal, Belen; Guinovart, Joan J.; Gomis, Ramon

    2007-01-01

    Oral administration of sodium tungstate is an effective treatment for diabetes in animal models. Several lines of evidence indicate the pancreatic beta cell as one of the targets of tungstate action. Here, we examined the molecular mechanism by which this compound exerts its effects on the beta cell line MIN6. Tungstate treatment induced phosphorylation and subsequent activation of p38 and PI3K which in turn are implicated in tungstate PDX-1 nuclear localization and activation. Although no effect was observed in glucose-induced insulin secretion we found that tungstate activates basal insulin release, a process driven, at least in part, by activation of p38. These results show a direct involvement of p38 and PI3K phosphorylation in the mechanism of action of tungstate in the beta cell

  19. Radiation initiated copolymerization of allyl alcohol with acrylonitrile

    International Nuclear Information System (INIS)

    Solpan, Dilek; Guven, Olgun

    1996-01-01

    Copolymerization of allyl alcohol (AA) with acrylonitrile (AN) initiated by γ-rays has been investigated to determine the respective reactivity ratios. Three different experimental techniques, namely Fourier Transform Infrared (FTIR), Ultraviolet (UV/vis) and elemental analysis (EA) have been used for the determination of copolymer compositions. Fineman-Ross (FR), Kelen-Tudos (KT), Non-Linear Least Square (NLLS) Analysis and Q-e methods have been applied to the three sets of experimental data. It has been concluded that data obtained from elemental analysis as applied to the Non-Linear Least Square approach gave the most reliable reactivity ratios as 2.09 and 0.40 for acrylonitrile and allyl alcohol, respectively. (Author)

  20. Study on irradiated polymerization of acrylonitrile by NMR

    International Nuclear Information System (INIS)

    Zhao Xin; Lin Hao

    1999-01-01

    Sup 13 C CP/MAS spectra and nuclear Overhauser effects (NOE) at room temperature have been measured for acrylonitrile (AN) in homophase irradiated polymerization. With the increase of radiation dose the chemical shift of cracking peaks and NOE are variation. This implies that the polymerized mechanism of AN were changed with the variation of irradiated doses and dose rate. There is the stronger affinity electron group (-CN) in acrylonitrile monomer. It may be polymerized by various ways and mechanism and be gained the polymer of difference structures and molecular weight of polyacrylonitrile (PAN). Starmicarbon and Starker obtained higher molecular weight of polyacrylonitrile by peroxysulfate-pyrosulfite in oxidation-reduction system. The superhigh molecular weight of PAN was synthesized chemically according to the method of Wu et. al. by suspension polymerization. In this paper we discussed that the relative concentrations of steric dyads and triads in the chain structure in PAN and the irradiation polymerized mechanism of acrylonitrile monomer in room temperature by different dose and dose rate

  1. Stereospecific polymerization of acrylonitrile using acrylonitrile-urea canal complex initiated by γ-ray irradiation

    International Nuclear Information System (INIS)

    Yamazaki, Hitoshi; Miyazaki, Yukio; Kamide, Kenji

    1991-01-01

    An attempt was made to clarify the effect of polymerization conditions (e.g., the content of chain transfer reagent, irradiation dose, acrylonitrile (AN)-urea ratio, aging time) on the stereoregularity, the viscosity-average molecular weight M ν , and the conversion in the radiation-induced polymerization of AN-urea canal complex in the presence of radical chain transfer reagent including alkyl mercaptans, alkylamines, alkyl alcohols and chloroform. The addition of n-butyl mercaptan (n-BM) to AN-urea system slowed down the rate of the canal complex formation and decreased the amount of the canal complexes formed. The role of n-BM on the formation of AN-urea canal complex was also examined by DSC. The enthalpy of fusion (ΔH) of AN solid in AN-n-BM-urea system decreased with elapse of aging time, although ΔH of n-BM was almost constant in the whole range of aging time. From these findings, it was concluded that n-BM is not included in the AN-urea canal complex. The conversion decreased remarkably with an increase in n-BM content. When 2 mol%/AN of n-BM was added to AN, M ν was almost constant (ca. M ν = 2.0 x 10 5 ), irrespective of the amount of n-BM added. Addition of n-BM to AN-urea system brings about a small, but significant increase in the content of isotactic triad (mm) by 5 to 14%. (author)

  2. Tungstate-targeting of BKαβ1 channels tunes ERK phosphorylation and cell proliferation in human vascular smooth muscle.

    Directory of Open Access Journals (Sweden)

    Ana Isabel Fernández-Mariño

    Full Text Available Despite the substantial knowledge on the antidiabetic, antiobesity and antihypertensive actions of tungstate, information on its primary target/s is scarce. Tungstate activates both the ERK1/2 pathway and the vascular voltage- and Ca2+-dependent large-conductance BKαβ1 potassium channel, which modulates vascular smooth muscle cell (VSMC proliferation and function, respectively. Here, we have assessed the possible involvement of BKαβ1 channels in the tungstate-induced ERK phosphorylation and its relevance for VSMC proliferation. Western blot analysis in HEK cell lines showed that expression of vascular BKαβ1 channels potentiates the tungstate-induced ERK1/2 phosphorylation in a Gi/o protein-dependent manner. Tungstate activated BKαβ1 channels upstream of G proteins as channel activation was not altered by the inhibition of G proteins with GDPβS or pertussis toxin. Moreover, analysis of Gi/o protein activation measuring the FRET among heterologously expressed Gi protein subunits suggested that tungstate-targeting of BKαβ1 channels promotes G protein activation. Single channel recordings on VSMCs from wild-type and β1-knockout mice indicated that the presence of the regulatory β1 subunit was essential for the tungstate-mediated activation of BK channels in VSMCs. Moreover, the specific BK channel blocker iberiotoxin lowered tungstate-induced ERK phosphorylation by 55% and partially reverted (by 51% the tungstate-produced reduction of platelet-derived growth factor (PDGF-induced proliferation in human VSMCs. Our observations indicate that tungstate-targeting of BKαβ1 channels promotes activation of PTX-sensitive Gi proteins to enhance the tungstate-induced phosphorylation of ERK, and inhibits PDGF-stimulated cell proliferation in human vascular smooth muscle.

  3. Ammonium-tungstate-promoted growth of boron nitride nanotubes

    Science.gov (United States)

    E, Songfeng; Li, Chaowei; Li, Taotao; Geng, Renjie; Li, Qiulong; Lu, Weibang; Yao, Yagang

    2018-05-01

    Ammonium tungstate ((NH4)10W12O41 · xH2O) is a kind of oxygen-containing ammonium salt. The following study proves that it can be successfully used as a metal oxide alternative to produce boron oxide (B2O2) by oxidizing boron (B) in a traditional boron oxide chemical vapor deposition (BOCVD) process. This special oxidant promotes the simplistic fabrication of boron nitride nanotubes (BNNTs) in a conventional horizontal tube furnace, an outcome which may have resulted from its strong oxidizability. The experimental results demonstrate that the mole ratio of B and (NH4)10W12O41 · xH2O is a key parameter in determining the formation, quality and quantity of BNNTs when stainless steel is employed as a catalyst. We also found that Mg(NO3)2 and MgO nanoparticles (NPs) can be used as catalysts to grow BNNTs with the same precursor. The BNNTs obtained from the Mg(NO3)2 catalyst were straighter than those obtained from the MgO NP catalyst. This could have been due to the different physical forms of the catalysts that were used.

  4. Synthesis of lanthanum tungstate interconnecting nanoparticles by high voltage electrospinning

    Energy Technology Data Exchange (ETDEWEB)

    Keereeta, Yanee, E-mail: ynkeereeta@gmail.com [Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thongtem, Titipun, E-mail: ttpthongtem@yahoo.com [Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Materials Science Research Center, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thongtem, Somchai [Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Materials Science Research Center, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand)

    2015-10-01

    Graphical abstract: - Highlights: • La{sub 2}(WO{sub 4}){sub 3} as one of semiconducting materials. • H.V. electrospinning was used to synthesize La{sub 2}(WO{sub 4}){sub 3} interconnecting nanoparticles. • A promising material for photoemission. - Abstract: Lanthanum tungstate (La{sub 2}(WO{sub 4}){sub 3}) interconnecting nanoparticles in the shape of fibers were successfully synthesized by electrospinning in combination with high temperature calcination. In this research, calcination temperature for the synthesis of the fibers evidently influenced the diameter, morphology and crystalline degree. The crystalline monoclinic La{sub 2}(WO{sub 4}){sub 3} fibers with 200–700 nm in diameter, two main Raman peaks at 945 and 927 cm{sup −1}, FTIR stretching modes at 936 and 847 cm{sup −1}, 2.02 eV energy gap and 415–430 nm blue emission were synthesized by calcination of inorganic/organic hybrid fibers at 750 °C for 5 h, characterized by X-ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy (TEM), selected area electron diffraction (SAED), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, UV–visible spectroscopy and photoluminescence (PL) spectroscopy. The surface of the composite fibers before calcination was very smooth. Upon calcination the composite fibers at 750 °C for 5 h, they were transformed into nanoparticles join together in the shape of fibers with rough surface.

  5. Investigation of behaviour of iron (3) microimpurity in ammonium tungstate solutions

    International Nuclear Information System (INIS)

    Vasil'ev, M.A.; Taushkanov, V.P.; Rumyantsev, V.K.; Andronov, E.A.

    1978-01-01

    To determine the purification optimum conditions of ammonium tungstate concentrated solutions from iron(3) microimpurities the behaviour of iron(3) with 10 -5 -10 -4 mol/l concentration in these solutions is studied. Concentration of hydrolyzed iron forms has been determined by spectrophotometric and radiometric methods. It is stated, that the processes of hydrolysis and aggregation of dispersed-colloid iron particles in tungstate solutions is generally over during the first 50 hours. It is shown, that a part of iron hydroxide particles of dimension less than 200 A increases with ammonium tungstate concentration increasing. Residual iron concentration also increases under the same conditions. The increasing of efficiency of solution purification is due to decreasing of carbon dispersion, applied for this purpose, and also modification of their surface by hydroxides of multivalent metas as zirconium for example

  6. 21 CFR 177.1020 - Acrylonitrile/butadiene/sty-rene co-polymer.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acrylonitrile/butadiene/sty-rene co-polymer. 177... SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances.../butadiene/sty-rene co-polymer. Acrylonitrile/butadiene/styrene copolymer identified in this section may be...

  7. Hydrothermal syntheses and characterization of uranyl tungstates with electro-neutral structural units

    Energy Technology Data Exchange (ETDEWEB)

    Balboni, Enrica; Burns, Peter C. [Univ. of Notre Dame, IN (United States). Dept. of Civil and Enviromental Engineering and Earth Sciences; Univ. of Notre Dame, IN (United States). Dept. of Chemistry and Biochemistry

    2015-11-01

    Two uranyl tungstates, (UO{sub 2})(W{sub 2}O{sub 7})(H{sub 2}O){sub 3} (1) and (UO{sub 2}){sub 3}(W{sub 2}O{sub 8})F{sub 2}(H{sub 2}O){sub 3} (2), were synthesized under hydrothermal conditions at 220 C and were structurally, chemically, and spectroscopically characterized. 1 Crystallizes in space group Pbcm, a = 6.673(5) Aa, b = 12.601(11) Aa, c = 11.552 Aa; 2 is in C2/m, a = 13.648(1) Aa, b = 16.852(1) Aa, c = 9.832(1) Aa, β = 125.980(1) {sup circle}. In 1 the U(VI) cations are present as (UO{sub 2}){sup 2+} uranyl ions that are coordinated by five oxygen atoms to give pentagonal bipyramids. These share two edges with two tungstate octahedra and single vertices with four additional octahedra, resulting in a sheet with the iriginite-type anion topology. Only water molecules are located in the interlayer. The structural units of 2 consist of (UO{sub 2}){sup 2+} uranyl oxy-fluoride pentagonal bipyramids present as either [UO{sub 2}F{sub 2}O{sub 3}]{sup -6} or [UO{sub 2}FO{sub 4}]{sup -5}, and strongly distorted tungstate octahedra. The linkage of uranyl pentagonal bipyramids and tungstate octahedra gives a unique sheet anion topology consisting of pentagons, squares and triangles. In 2, the uranyl tungstates sheets are connected into a novel electro-neutral three-dimensional framework through dimers of uranyl pentagonal bipyramids. These dimers connecting the sheets share an edge defined by F anions. 2 is the first example of a uranyl tungstate oxy-fluoride, and 1 and 2 are rare examples of uranyl compounds containing electro-neutral structural units.

  8. Kinetic and equilibrium studies of acrylonitrile binding to cytochrome c peroxidase and oxidation of acrylonitrile by cytochrome c peroxidase compound I

    Energy Technology Data Exchange (ETDEWEB)

    Chinchilla, Diana, E-mail: Diana_Chinchilla@yahoo.com; Kilheeney, Heather, E-mail: raindropszoo@yahoo.com; Vitello, Lidia B., E-mail: lvitello@niu.edu; Erman, James E., E-mail: jerman@niu.edu

    2014-01-03

    Highlights: •Cytochrome c peroxidase (CcP) binds acrylonitrile in a pH-independent fashion. •The spectrum of the CcP/acrylonitrile complex is that of a 6c–ls ferric heme. •The acrylonitrile/CcP complex has a K{sub D} value of 1.1 ± 0.2 M. •CcP compound I oxidizes acrylonitrile with a maximum turnover rate of 0.61 min{sup −1}. -- Abstract: Ferric heme proteins bind weakly basic ligands and the binding affinity is often pH dependent due to protonation of the ligand as well as the protein. In an effort to find a small, neutral ligand without significant acid/base properties to probe ligand binding reactions in ferric heme proteins we were led to consider the organonitriles. Although organonitriles are known to bind to transition metals, we have been unable to find any prior studies of nitrile binding to heme proteins. In this communication we report on the equilibrium and kinetic properties of acrylonitrile binding to cytochrome c peroxidase (CcP) as well as the oxidation of acrylonitrile by CcP compound I. Acrylonitrile binding to CcP is independent of pH between pH 4 and 8. The association and dissociation rate constants are 0.32 ± 0.16 M{sup −1} s{sup −1} and 0.34 ± 0.15 s{sup −1}, respectively, and the independently measured equilibrium dissociation constant for the complex is 1.1 ± 0.2 M. We have demonstrated for the first time that acrylonitrile can bind to a ferric heme protein. The binding mechanism appears to be a simple, one-step association of the ligand with the heme iron. We have also demonstrated that CcP can catalyze the oxidation of acrylonitrile, most likely to 2-cyanoethylene oxide in a “peroxygenase”-type reaction, with rates that are similar to rat liver microsomal cytochrome P450-catalyzed oxidation of acrylonitrile in the monooxygenase reaction. CcP compound I oxidizes acrylonitrile with a maximum turnover number of 0.61 min{sup −1} at pH 6.0.

  9. Periodic Sorption of Tungstate Ions on Anionite AV-17-8

    Directory of Open Access Journals (Sweden)

    D’yachenko Aleksandr

    2017-01-01

    Full Text Available The multiple sorption of sodium tungstate resulting from the autoclave-soda digestion of a tungsten-bearing concentrate was studied using anion-exchange resin AV-17-8. The choice of ion exchange resin was carried out under static conditions using highly basic anionites. The sorption and desorption plots for tungstate and carbonate ions were demonstrated under dynamic conditions. The total dynamic capacity of the resin was estimated for each species of the ions in three sorption cycles. The applicability of the AV-17-8 resin as a sorbent in the autoclave-soda process flowsheet was determined.

  10. Equivalent lifetime prediction of acrylonitrile butadiene rubber for thermal aging

    Energy Technology Data Exchange (ETDEWEB)

    Kim, K. Y.; Jang, H. K. [KAERI, Taejon (Korea, Republic of); Ryu, B. H. [Dongguk Universty, Gyeongju (Korea, Republic of); Lee, C. [Chungbuk University, Cheongju (Korea, Republic of)

    2003-07-01

    Thermal degradation of acrylonitrile butadiene rubber(NBR), which is used for O-ring material as elastomeric sealed diaphragm valve in the nuclear power plants, is examined. The thermal degradation is accelerated at 130 .deg. C by arrhenius exploit method using the activation energy calculated by thermogravimetric analysis. The weight loss temperature and glass transition temperature are verified for thermally aged NBR. The relationship between dynamic mechanical properties and elongation at break are also investigated. The threshold valued of thermally aged NBR is a ten year in the change of elongation at break.

  11. Equivalent lifetime prediction of acrylonitrile butadiene rubber for thermal aging

    International Nuclear Information System (INIS)

    Kim, K. Y.; Jang, H. K.; Ryu, B. H.; Lee, C.

    2003-01-01

    Thermal degradation of acrylonitrile butadiene rubber(NBR), which is used for O-ring material as elastomeric sealed diaphragm valve in the nuclear power plants, is examined. The thermal degradation is accelerated at 130 .deg. C by arrhenius exploit method using the activation energy calculated by thermogravimetric analysis. The weight loss temperature and glass transition temperature are verified for thermally aged NBR. The relationship between dynamic mechanical properties and elongation at break are also investigated. The threshold valued of thermally aged NBR is a ten year in the change of elongation at break

  12. Role of sodium tungstate as a potential antiplatelet agent

    Directory of Open Access Journals (Sweden)

    Fernández-Ruiz R

    2015-05-01

    Full Text Available Rebeca Fernández-Ruiz,1,2 Marc Pino,3 Begoña Hurtado,4 Pablo García de Frutos,4 Carolina Caballo,3 Ginés Escolar,3 Ramón Gomis,1,2,5 Maribel Diaz-Ricart3 1Diabetes and Obesity Research Laboratory, Institut d'Investigacions Biomediques August Pi i Sunyer (IDIBAPS, Rosellón, Barcelona, 2Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas, Barcelona, 3Hemotherapy–Hemostasis, Hospital Clínic, Universidad de Barcelona, IDIBAPS, Villarroel, Barcelona, 4Institutode Investigaciones Biomédicas de Barcelona, Consejo Superior de Investigaciones Científicas, Institut d’Investigacions Biomediques August Pi i Sunyer, Rosellón, Barcelona, 5Hospital Clinic, Universitat de Barcelona, Villarroel, Barcelona, Spain Purpose: Platelet inhibition is a key strategy in the management of atherothrombosis. However, the large variability in response to current strategies leads to the search for alternative inhibitors. The antiplatelet effect of the inorganic salt sodium tungstate (Na2O4W, a protein tyrosine phosphatase 1B (PTP1B inhibitor, has been investigated in this study.Methods: Wild-type (WT and PTP1B knockout (PTP1B-/- mice were treated for 1 week with Na2O4W to study platelet function with the platelet function analyzer PFA-100, a cone-and-plate analyzer, a flat perfusion chamber, and thrombus formation in vivo. Human blood aliquots were incubated with Na2O4W for 1 hour to measure platelet function using the PFA-100 and the annular perfusion chamber. Aggregometry and thromboelastometry were also performed.Results: In WT mice, Na2O4W treatment prolonged closure times in the PFA-100 and decreased the surface covered (%SC by platelets on collagen. Thrombi formed in a thrombosis mice model were smaller in animals treated with Na2O4W (4.6±0.7 mg vs 8.9±0.7 mg; P<0.001. Results with Na2O4W were similar to those in untreated PTP1B-/- mice (5.0±0.3 mg. Treatment of the PTP1B-/- mice with Na2O4W modified only

  13. Sodium Tungstate for Promoting Mesenchymal Stem Cell Chondrogenesis.

    Science.gov (United States)

    Khader, Ateka; Sherman, Lauren S; Rameshwar, Pranela; Arinzeh, Treena L

    2016-12-15

    Articular cartilage has a limited ability to heal. Mesenchymal stem cells (MSCs) derived from the bone marrow have shown promise as a cell type for cartilage regeneration strategies. In this study, sodium tungstate (Na 2 WO 4 ), which is an insulin mimetic, was evaluated for the first time as an inductive factor to enhance human MSC chondrogenesis. MSCs were seeded onto three-dimensional electrospun scaffolds in growth medium (GM), complete chondrogenic induction medium (CCM) containing insulin, and CCM without insulin. Na 2 WO 4 was added to the media leading to final concentrations of 0, 0.01, 0.1, and 1 mM. Chondrogenic differentiation was assessed by biochemical analyses, immunostaining, and gene expression. Cytotoxicity using human peripheral blood mononuclear cells (PBMCS) was also investigated. The chondrogenic differentiation of MSCs was enhanced in the presence of low concentrations of Na 2 WO 4 compared to control, without Na 2 WO 4 . In the induction medium containing insulin, cells in 0.01 mM Na 2 WO 4 produced significantly higher sulfated glycosaminoglycans, collagen type II, and chondrogenic gene expression than all other groups at day 28. Cells in 0.1 mM Na 2 WO 4 had significantly higher collagen II production and significantly higher sox-9 and aggrecan gene expression compared to control at day 28. Cells in GM and induction medium without insulin containing low concentrations of Na 2 WO 4 also expressed chondrogenic markers. Na 2 WO 4 did not stimulate PBMC proliferation or apoptosis. The results demonstrate that Na 2 WO 4 enhances chondrogenic differentiation of MSCs, does not have a toxic effect, and may be useful for MSC-based approaches for cartilage repair.

  14. Poly(acrylonitrile)chitosan composite membranes for urease immobilization.

    Science.gov (United States)

    Gabrovska, Katya; Georgieva, Aneliya; Godjevargova, Tzonka; Stoilova, Olya; Manolova, Nevena

    2007-05-10

    (Poly)acrylonitrile/chitosan (PANCHI) composite membranes were prepared. The chitosan layer was deposited on the surface as well as on the pore walls of the base membrane. This resulted in the reduction of the pore size of the membrane and in an increase of their hydrophilicity. The pore structure of PAN and PANCHI membranes were determined by TEM and SEM analyses. It was found that the average size of the pore under a selective layer base PAN membrane is 7 microm, while the membrane coated with 0.25% chitosan shows a reduced pore size--small or equal to 5 microm and with 0.35% chitosan--about 4 microm. The amounts of the functional groups, the degree of hydrophilicity and transport characteristics of PAN/Chitosan composite membranes were determined. Urease was covalently immobilized onto all kinds of PAN/chitosan composite membranes using glutaraldehyde. Both the amount of bound protein and relative activity of immobilized urease were measured. The highest activity (94%) was measured for urease bound to PANCHI2 membranes (0.25% chitosan). The basic characteristics (pH(opt), pH(stability), T(opt), T(stability), heat inactivation and storage stability) of immobilized urease were determined. The obtained results show that the poly(acrylonitrile)chitosan composite membranes are suitable for enzyme immobilization.

  15. The effects of tungstate on skin lesions caused by PPD in rats.

    Science.gov (United States)

    Lee, Sang-Hee; Cho, Hyun-Gug; Lee, Sang-Il

    2008-04-01

    P-phenylenediamine (PPD) has been used as one of the ingredients in hair dye. The purpose of this study is to investigate the skin toxicity of PPD application in a tungstate-induced xanthine oxidase (XO) deficient animal model. PPD (2.5% PPD in 2% NH4OH) was applied to rat skin (25 mg/16.5 cm2) five times every other day in rats fed a standard diet (SD) or a tungstate supplemented diet (TD). The skin structure in the SD and the TD group was intact, whereas XO activity was not detected in the TD group during experimental periods. Furthermore, there were no differences between the SD and the TD group in dermal reactive oxygen species (ROS) scavenging enzymes. In these experimental conditions, although XO activity was not detected in the applied PPD rats fed a tungstate supplemented diet (PTD) group, it showed more severe tissue damage compared with the applied PPD rats fed a standard diet (PSD) group. In addition, the PTD group showed higher increased rates of ROS scavenging enzyme activity and lipid peroxide (LPO) content, and decreased glutathione (GSH) content than in the PSD group. In conclusion, the increase of PPD dermal toxicity in tungstate-induced XO deficient animals may be due to excessive ROS via ROS imbalance during PPD skin application.

  16. Distorted octahedral coordination of tungstate in a subfamily of specific binding proteins

    NARCIS (Netherlands)

    Hollenstein, K.; Comellas-Bigler, M.; Bevers, L.E.; Feiters, M.C.; Meyer-Klaucke, W.; Hagedoorn, P.L.; Locher, K.P.

    2009-01-01

    Bacteria and archaea import molybdenum and tungsten from the environment in the form of the oxyanions molybdate (MoO4 2?) and tungstate (WO4 2?). These substrates are captured by an external, high-affinity binding protein, and delivered to ATP binding cassette transporters, which move them across

  17. Tungstate-Targeting of BKαβ1 Channels Tunes ERK Phosphorylation and Cell Proliferation in Human Vascular Smooth Muscle

    OpenAIRE

    López López, José Ramón; Fernández Mariño, Ana Isabel; Cidad, Pilar; Zafra, Delia; Nocito, Laura; Domínguez, Jorge; Oliván Viguera, Aida; Köhler, Ralf; Pérez García, María Teresa; Valverde, Miguel Ángel; Guinovart, Joan J.; Fernández Fernández, José Manuel

    2015-01-01

    Producción Científica Despite the substantial knowledge on the antidiabetic, antiobesity and antihypertensive actions of tungstate, information on its primary target/s is scarce. Tungstate activates both the ERK1/2 pathway and the vascular voltage- and Ca2+-dependent large-conductance BKαβ1 potassium channel, which modulates vascular smooth muscle cell (VSMC) proliferation and function, respectively. Here, we have assessed the possible involvement of BKαβ1 channels in the tungstate-induced...

  18. Kinetic and equilibrium studies of acrylonitrile binding to cytochrome c peroxidase and oxidation of acrylonitrile by cytochrome c peroxidase compound I.

    Science.gov (United States)

    Chinchilla, Diana; Kilheeney, Heather; Vitello, Lidia B; Erman, James E

    2014-01-03

    Ferric heme proteins bind weakly basic ligands and the binding affinity is often pH dependent due to protonation of the ligand as well as the protein. In an effort to find a small, neutral ligand without significant acid/base properties to probe ligand binding reactions in ferric heme proteins we were led to consider the organonitriles. Although organonitriles are known to bind to transition metals, we have been unable to find any prior studies of nitrile binding to heme proteins. In this communication we report on the equilibrium and kinetic properties of acrylonitrile binding to cytochrome c peroxidase (CcP) as well as the oxidation of acrylonitrile by CcP compound I. Acrylonitrile binding to CcP is independent of pH between pH 4 and 8. The association and dissociation rate constants are 0.32±0.16 M(-1) s(-1) and 0.34±0.15 s(-1), respectively, and the independently measured equilibrium dissociation constant for the complex is 1.1±0.2 M. We have demonstrated for the first time that acrylonitrile can bind to a ferric heme protein. The binding mechanism appears to be a simple, one-step association of the ligand with the heme iron. We have also demonstrated that CcP can catalyze the oxidation of acrylonitrile, most likely to 2-cyanoethylene oxide in a "peroxygenase"-type reaction, with rates that are similar to rat liver microsomal cytochrome P450-catalyzed oxidation of acrylonitrile in the monooxygenase reaction. CcP compound I oxidizes acrylonitrile with a maximum turnover number of 0.61 min(-1) at pH 6.0. Copyright © 2013 Elsevier Inc. All rights reserved.

  19. Selective Vulnerability of the Cochlear Basal Turn to Acrylonitrile and Noise

    International Nuclear Information System (INIS)

    Pouyatos, B.; Gearhart, C.A.; Miller, A.N.; Fulton, S.; Fechter, L.D.; Pouyatos, B.

    2009-01-01

    Exposure to acrylonitrile, a high-production industrial chemical, can promote noise-induced hearing loss (NIHL) in the rat even though this agent does not itself produce permanent hearing loss. The mechanism by which acrylonitrile promotes NIHL includes oxidative stress as antioxidant drugs can partially protect the cochlea from acrylonitrile + noise. Acrylonitrile depletes glutathione levels while noise can increase the formation of reactive oxygen species. It was previously noted that the high-frequency or basal turn of the cochlea was particularly vulnerable to the combined effects of acrylonitrile and noise when the octave band noise (OBN) was centered at 8 k Hz. Normally, such a noise would be expected to yield damage at a more apical region of the cochlea. The present study was designed to determine whether the basal cochlea is selectively sensitive to acrylonitrile or whether, by adjusting the frequency of the noise band, it would be possible to control the region of the auditory impairment. Rats were exposed to one of three different OBNs centered at different frequencies (4 k Hz, 110 dB and 8 or 16 k Hz at 97 dB) for 5 days, with and without administration of acrylonitrile (50 mg/kg/day). The noise was set to cause limited NIHL by itself. Auditory function was monitored by recording distortion products, by compound action potentials, and by performing cochlear histology. While the ACN-only and noise-only exposures induced no or little permanent auditory loss, the three exposures to acrylonitrile + noise produced similar auditory and cochlear impairments above 16 k Hz, despite the fact that the noise exposures covered 2 octaves. These observations show that the basal cochlea is much more sensitive to acrylonitrile + noise than the apical partition. They provide an initial basis for distinguishing the pattern of cochlear injury that results from noise exposure from that which occurs due to the combined effects of noise and a chemical contaminant.

  20. A general strategy toward the rational synthesis of metal tungstate nanostructures using plasma electrolytic oxidation method

    International Nuclear Information System (INIS)

    Jiang, Yanan; Liu, Baodan; Zhai, Zhaofeng; Liu, Xiaoyuan; Yang, Bing; Liu, Lusheng; Jiang, Xin

    2015-01-01

    Graphical abstract: A general strategy for the rational synthesis of tungstate nanostructure has been developed based on plasma electrolytic oxidation (PEO) technology (up). Using this method, ZnWO 4 and NiWO 4 nanostructures with controllable morphologies and superior crystallinity can be easily obtained (down), showing obvious advantage in comparison with conventional hydrothermal and sol–gel methods. - Highlights: • Plasma electrolyte oxidation (PEO) method has been used for the rational synthesis of tungstate nanostructures. • ZnWO 4 nanoplates have strong mechanical adhesion with porous TiO 2 film substrate. • The morphology and dimensional size of ZnWO 4 nanostructures can be selectively tailored by controlling the annealing temperature and growth time. • The PEO method can be widely applied to the growth of various metal oxides. - Abstract: A new method based on conventional plasma electrolytic oxidation (PEO) technology has been developed for the rational synthesis of metal tungstate nanostructures. Using this method, ZnWO 4 and NiWO 4 nanostructures with controllable morphologies (nanorods, nanosheets and microsheets) and superior crystallinity have been synthesized. It has been found that the morphology diversity of ZnWO 4 nanostructures can be selectively tailored through tuning the electrolyte concentration and annealing temperatures, showing obvious advantages in comparison to traditional hydrothermal and sol–gel methods. Precise microscopy analyses on the cross section of the PEO coating and ZnWO 4 nanostructures confirmed that the precursors initially precipitated in the PEO coating and its surface during plasma discharge process are responsible for the nucleation and subsequent growth of metal tungstate nanostructures by thermal annealing. The method developed in this work represents a general strategy toward the rational synthesis of metal oxide nanostructures and the formation mechanism of metal tungstate nanostructures fabricated by

  1. A general strategy toward the rational synthesis of metal tungstate nanostructures using plasma electrolytic oxidation method

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Yanan; Liu, Baodan, E-mail: baodanliu@imr.ac.cn; Zhai, Zhaofeng; Liu, Xiaoyuan; Yang, Bing; Liu, Lusheng; Jiang, Xin, E-mail: xjiang@imr.ac.cn

    2015-11-30

    Graphical abstract: A general strategy for the rational synthesis of tungstate nanostructure has been developed based on plasma electrolytic oxidation (PEO) technology (up). Using this method, ZnWO{sub 4} and NiWO{sub 4} nanostructures with controllable morphologies and superior crystallinity can be easily obtained (down), showing obvious advantage in comparison with conventional hydrothermal and sol–gel methods. - Highlights: • Plasma electrolyte oxidation (PEO) method has been used for the rational synthesis of tungstate nanostructures. • ZnWO{sub 4} nanoplates have strong mechanical adhesion with porous TiO{sub 2} film substrate. • The morphology and dimensional size of ZnWO{sub 4} nanostructures can be selectively tailored by controlling the annealing temperature and growth time. • The PEO method can be widely applied to the growth of various metal oxides. - Abstract: A new method based on conventional plasma electrolytic oxidation (PEO) technology has been developed for the rational synthesis of metal tungstate nanostructures. Using this method, ZnWO{sub 4} and NiWO{sub 4} nanostructures with controllable morphologies (nanorods, nanosheets and microsheets) and superior crystallinity have been synthesized. It has been found that the morphology diversity of ZnWO{sub 4} nanostructures can be selectively tailored through tuning the electrolyte concentration and annealing temperatures, showing obvious advantages in comparison to traditional hydrothermal and sol–gel methods. Precise microscopy analyses on the cross section of the PEO coating and ZnWO{sub 4} nanostructures confirmed that the precursors initially precipitated in the PEO coating and its surface during plasma discharge process are responsible for the nucleation and subsequent growth of metal tungstate nanostructures by thermal annealing. The method developed in this work represents a general strategy toward the rational synthesis of metal oxide nanostructures and the formation mechanism of

  2. Tungsten transport protein A (WtpA) in Pyrococcus furiosus: the first member of a new class of tungstate and molybdate transporters.

    Science.gov (United States)

    Bevers, Loes E; Hagedoorn, Peter-Leon; Krijger, Gerard C; Hagen, Wilfred R

    2006-09-01

    A novel tungstate and molybdate binding protein has been discovered from the hyperthermophilic archaeon Pyrococcus furiosus. This tungstate transport protein A (WtpA) is part of a new ABC transporter system selective for tungstate and molybdate. WtpA has very low sequence similarity with the earlier-characterized transport proteins ModA for molybdate and TupA for tungstate. Its structural gene is present in the genome of numerous archaea and some bacteria. The identification of this new tungstate and molybdate binding protein clarifies the mechanism of tungstate and molybdate transport in organisms that lack the known uptake systems associated with the ModA and TupA proteins, like many archaea. The periplasmic protein of this ABC transporter, WtpA (PF0080), was cloned and expressed in Escherichia coli. Using isothermal titration calorimetry, WtpA was observed to bind tungstate (dissociation constant [K(D)] of 17 +/- 7 pM) and molybdate (K(D) of 11 +/- 5 nM) with a stoichiometry of 1.0 mol oxoanion per mole of protein. These low K(D) values indicate that WtpA has a higher affinity for tungstate than do ModA and TupA and an affinity for molybdate similar to that of ModA. A displacement titration of molybdate-saturated WtpA with tungstate showed that the tungstate effectively replaced the molybdate in the binding site of the protein.

  3. Structure and activity of tellurium-cerium oxide acrylonitrile catalysts

    International Nuclear Information System (INIS)

    Bart, J.C.J.; Giordano, N.

    1982-01-01

    Ammoxidation of propylene to acrylonitrile (ACN) was investigated over various silica-supported (Te,Ce)O catalysts at 360 and 440 0 C. The binary oxide system used consists of a single nonstoichiometric fluorite-type phase α-(Ce,Te)O 2 up to about 80 mole% TeO 2 and a tellurium-saturated solid solution β-(Ce,Te)O 2 at higher tellurium concentrations. The ACN yield varies almost linearly with the tellurium content of (Ce,Te)O 2 . The β-(Ce,Te)O 2 phase is the most active component of the system (propylene conversion and ACN selectivity at 440 C of 76.7 and 74%, respectively) and is slightly more selective to ACN than α-Te0 2 . Tellurium reduces the overoxidation properties of cerium and selective oxidation occurs through Te(IV)-bonded oxygen

  4. Studies of lead tungstate crystal matrices in high energy beams for the CMS electromagnetic calorimeter at the LHC

    CERN Document Server

    Alexeev, G; Baillon, Paul; Barney, D; Bassompierre, Gabriel; Bateman, E; Bell, K W; Benhammou, Ya; Bloch, P; Bomestar, D; Borgia, B; Bourotte, J; Burge, S R; Cameron, W; Chipaux, Rémi; Cockerill, D J A; Connolly, J; Dafinei, I; Denes, P; Depasse, P; Deiters, K; Dobrzynski, Ludwik; El-Mamouni, H; Faure, J L; Felcini, Marta; Finger, M H; Flügel, T; Gautheron, F; Givernaud, Alain; Gninenko, S N; Godinovic, N; Graham, D J; Guillaud, J P; Guschin, E; Haguenauer, Maurice; Hillemanns, H; Hofer, H; Ille, B; Jääskeläinen, S; Katchanov, V A; Kennedy, B W; Kirn, T; Korzhik, M V; Lassila-Perini, K M; Lebeau, M; Lebrun, P; Lecoq, P; Lecoeur, Gérard; Lecomte, P; Leonardi, E; Locci, E; Loos, R; Ma, D; Martin, F; Mendiburu, J P; Musienko, Yu V; Nédélec, P; Nessi-Tedaldi, F; Newbold, D; Newman, H; Oukhanov, M; Pacciani, L; Peigneux, J P; Pirro, S; Popov, S; Puljak, I; Purves, C; Renker, D; Rondeaux, F; Rosso, E; Rusack, R W; Rykaczewski, H; Schmitz, D; Schneegans, M; Schwenke, J; Seez, Christopher J; Semeniouk, I N; Shagin, P M; Shevchenko, S; Shi, X; Sillou, D; Simohand, D; Singovsky, A V; Soric, I; Smith, B; Stephenson, R; Verrecchia, P; Vialle, J P; Virdee, Tejinder S; Zhu, R Y

    1997-01-01

    Using matrices of lead tungstate crystals energy resolutions better than 0.6% at 100 GeV have been achieved in the test beam in 1995. It has been demonstrated that a lead tungstate electromagnetic calorimeter read out by avalanche photodiodes can consistently achieve the excellent energy resolutions necessary to justify its construction in the CMS detector. The performance achieved has been understood in terms of the properties of the crystals and photodetectors.

  5. Determination of potentially carcinogenic compounds in food : trace analysis of vinylchloride, vinylidenechloride, acrylonitrile, epichlorohydrin and diethylpyrocarbonate

    NARCIS (Netherlands)

    Lierop, van J.B.H.

    1979-01-01

    Toxicological evidence shows that some monomers present in packaging materials may be carcinogenic. These monomers, notably vinylchloride, vinylidenechloride, acrylonitrile and epichlorohydrin, may migrate from the packaging material into the food. Therefore, severe limits are set to the contents of

  6. Pre-irradiation induced emulsion graft polymerization of acrylonitrile onto polyethylene nonwoven fabric

    International Nuclear Information System (INIS)

    Liu Hanzhou; Yu Ming; Deng Bo; Li Linfan; Jiang Haiqing; Li Jingye

    2012-01-01

    Acrylonitrile has been widely used in the modification of polymers by graft polymerization. In the present work, pre-irradiation induced emulsion graft polymerization method is used to introduce acrylonitrile onto PE nonwoven fabric instead of the traditional reaction in organic solvents system. The degree of grafting (DG) is measured by gravimetric method and the kinetics of the graft polymerization is studied. The existence of the graft chains is proven by Fourier transform infrared spectroscopy (FT-IR) analysis. Thermal stability of the grafted polymer is measured by Thermogravimetric analysis (TGA). - Highlights: → Acrylonitrile is grafted onto pre-irradiated polyethylene (PE) nonwoven fabrics. → Emulsion system is applied, for the graft polymerization avoids organic solvent. → Kinetic of the pre-irradiation induced graft polymerization is studied. → Optimal condition is determined at the temperature below the b.p. of acrylonitrile.

  7. Reactive magnetron sputtering deposition of bismuth tungstate onto titania nanoparticles for enhancing visible light photocatalytic activity

    Energy Technology Data Exchange (ETDEWEB)

    Ratova, Marina, E-mail: marina_ratova@hotmail.com [Surface Engineering Group, School of Engineering, Manchester Metropolitan University, Manchester, M1 5GD (United Kingdom); Kelly, Peter J.; West, Glen T. [Surface Engineering Group, School of Engineering, Manchester Metropolitan University, Manchester, M1 5GD (United Kingdom); Tosheva, Lubomira; Edge, Michele [School of Science and the Environment, Manchester Metropolitan University, Manchester M1 5GD (United Kingdom)

    2017-01-15

    Highlights: • Bismuth tungstate coatings were deposited by reactive magnetron sputtering. • Oscillating bowl was introduced to the system to enable coating of nanopartulates. • Deposition of Bi{sub 2}WO{sub 6} enhanced visible light activity of titania nanoparticles. • The best results were obtained for coating with Bi:W ratio of approximately 2:1. • Deposition of Bi{sub 2}WO{sub 6} onto TiO{sub 2} resulted in more efficient electron-hole separation. - Abstract: Titanium dioxide − bismuth tungstate composite materials were prepared by pulsed DC reactive magnetron sputtering of bismuth and tungsten metallic targets in argon/oxygen atmosphere onto anatase and rutile titania nanoparticles. The use of an oscillating bowl placed beneath the two magnetrons arranged in a co-planar closed field configuration enabled the deposition of bismuth tungstate onto loose powders, rather than a solid substrate. The atomic ratio of the bismuth/tungsten coatings was controlled by varying the power applied to each target. The effect of the bismuth tungstate coatings on the phase, optical and photocatalytic properties of titania was investigated by X-ray diffraction, energy-dispersive X-ray spectroscopy (EDX), Brunauer–Emmett–Teller (BET) surface area measurements, transmission electron microscopy (TEM), UV–vis diffuse reflectance spectroscopy and an acetone degradation test. The latter involved measurements of the rate of CO{sub 2} evolution under visible light irradiation of the photocatalysts, which indicated that the deposition of bismuth tungstate resulted in a significant enhancement of visible light activity, for both anatase and rutile titania particles. The best results were achieved for coatings with a bismuth to tungsten atomic ratio of 2:1. In addition, the mechanism by which the photocatalytic activity of the TiO{sub 2} nanoparticles was enhanced by compounding it with bismuth tungstate was studied by microwave cavity perturbation. The results of these

  8. Synthesis, Characterization and Photophysical Properties of Pyridine-Carbazole Acrylonitrile Derivatives

    Science.gov (United States)

    Pérez-Gutiérrez, Enrique; Percino, M. Judith; Chapela, Víctor M.; Cerón, Margarita; Maldonado, José Luis; Ramos-Ortiz, Gabriel

    2011-01-01

    We synthesized three novel highly fluorescent compounds, 2-(2’-pyridyl)-3-(N-ethyl-(3’-carbazolyl))acrylonitrile, 2-(3”-pyridyl)-3-(N-ethyl-(3’-carbazolyl))acrylonitrile, and 2-(4-pyridyl)-3-(N-ethyl-(3’-carbazolyl))acrylonitrile by Knoevenagel condensation. The first two were synthesized without solvent in the presence of piperidine as a catalyst; the third was synthesized without a catalyst and with N,N-dimethylformamide as a solvent. In solution, the molar absorption coefficients showed absorptions at 380, 378, and 396 nm, respectively; in solid state, absorptions were at 398, 390, and 442 nm, respectively. The fluorescence emission was at 540, 540 and 604 nm, respectively, the 2-(4-pyridyl)-3-(N-ethyl-(3’-carbazolyl))acrylonitrile showed a red shift in the emission of 64 nm compared to the other two compounds. The fluorescence quantum yield for the compounds in powder form showed values of 0.05, 0.14, and 0.006, respectively; compared with the value measured for the Alq3 reference, 2-(3”-pyridyl)-3-(N-ethyl-(3’-carbazolyl))acrylonitrile had a lightly higher value. The third harmonic generation measurement for 2-(2’-pyridyl)-3-(N-ethyl-(3’-carbazolyl))acrylonitrile yielded a χ(3) value of 5.5 × 10−12 esu, similar to that reported for commercial polymers. PMID:28880006

  9. Nickel tungstate (NiWO4) nanoparticles/graphene composites: preparation and photoelectrochemical applications

    Science.gov (United States)

    Hosseini, Seyyedamirhossein; Farsi, Hossein; Moghiminia, Shokufeh; Zubkov, Tykhon; Lightcap, Ian V.; Riley, Andrew; Peters, Dennis G.; Li, Zhihai

    2018-05-01

    Nickel tungstate/graphene composite was synthesized in various compositions with application of a hydrothermal method. Chemical composition and morphology of each sample was studied via application of x-ray diffraction and transmission electron microscopy techniques. In the continuous, a photosystem was obtained by deposition of composite sample on a fluorine-doped tin oxide electrode with application of electrophoretic method. Electrode morphology was studied by employment of atomic force microscopy and SEM techniques. Eventually, light conversion properties and involved mechanism of fabricated photosystem was studied with application of the Mott–Schottky method. Our results confirmed that the optimum ratio between graphene and nickel tungstate is in the regime of 1:1.

  10. Distribution of tungstate in pregnant mice and effects on embryonic cells in vitro

    International Nuclear Information System (INIS)

    Wide, M.; Danielsson, B.R.G.; Dencker, L.

    1986-01-01

    Whole-body autoradiography and impulse counting experiments were used to study the distribution and retention of radioactivity in the pregnant mouse after administration of [ 185 W]tungstate. A rapid uptake was found in a number of tissues - skeleton, red pulp of the spleen, adrenal, liver, thyroid, pituitary, and ovary - and in the intestine and kidneys, through which it was rapidly excreted. 185 W was also readily transported from mother to fetus, although more in late than in early gestation. The largest metal retention was found in the maternal skeleton, kidneys, and spleen and in visceral yolk sac epithelium and the skeleton of the fetus. Furthermore, in vitro cytotoxicity experiments showed inhibition by tungstate of cartilage production in limb bud mesenchymal cultures at concentrations similar to those found in vivo

  11. High-power Yb- and Tm-doped double tungstate channel waveguide lasers

    NARCIS (Netherlands)

    van Dalfsen, Koop; Geskus, D.; Ay, F.; Worhoff, Kerstin; Aravazhi, S.; Pollnau, Markus

    The potassium double tungstates KGd(WO4)2, KY(WO4)2, and KLu(WO4)2 are excellent candidates for solid-state lasers because of their high refractive index of ~2.0-2.1, the large transition cross-sections of rare-earth (RE3+) ions doped into these hosts, and a reasonably large thermal conductivity of

  12. Mechanism of chlorination of some actinide and fission product phosphates and tungstates in chloride melts

    International Nuclear Information System (INIS)

    Kryukova, A.I.; Chernikov, A.A.; Skiba, O.V.; Kazantsev, G.N.

    1989-01-01

    Results of kinetic studies on the chlorination of crystalline phosphates and tungstates of uranium, cerium, zirconium, and plutonium by gaseous carbon tetrachloride in melts of alkali metal chlorides at 973-1073 degree K are analyzed. A mathematical model of the process is proposed. Analysis of regression models allowed solution of the problem by statistical evaluation of the effective factors and prediction within the limits of the factors studied of the optimal conditions for the process

  13. Recycling of Chrome Tanned Leather Dust in Acrylonitrile Butadiene Rubber

    Science.gov (United States)

    El-Sabbagh, Salwa H.; Mohamed, Ola A.

    2010-06-01

    Concerns on environmental waste problem caused by chrome tanned leather wastes in huge amount have caused an increasing interest in developing this wastes in many composite formation. This leather dust was used as filler in acrylonitrile butadiene rubber (NBR) before treatment and after treatment with ammonia solution and sod. formate. Different formulations of NBR/ leather dust (untreated-treated with ammonia solution—treated with sod. formate) composites are prepared. The formed composite exhibit a considerable improvement in some of their properties such as rheometric characteristics especially with composites loaded with treated leather dust. Tensile strength, modulus at 100% elongation, hardness and youngs modulus were improved then by further loading start to be steady or decrease. Cross linking density in toluene were increased by incorporation of leather dust treated or untreated resulting in decreases in equilibrium swelling. Distinct increase in the ageing coefficient of both treated and untreated leather with drop in NBR vulcanizates without leather dust. Addition of leather dust treated or untreated exhibit better thermal stability.

  14. Development of Polythiophene/Acrylonitrile-Butadiene Rubbers for Artificial Muscle

    Science.gov (United States)

    Thipdech, Pacharavalee; Sirivat, Anuvat

    2007-03-01

    Electroactive polymers (EAPs) can respond to the applied electrical field by an extension or a retraction. In this work, we are interested in using an elastomeric blend for electroactive applications, acrylonitirle-butadiene rubber (NBR) containing a conductive polymer (Poly(3-thiopheneacetic acid, PTAA); the latter can be synthesized via oxidative polymerization. FT-IR, Thermogravimetric analysis (TGA), ^1H-NMR, UV-visible spectroscopy, and SEM are used to characterize the conductive polymer. Electrorheological properties are measured and investigated in terms of acrylonitrile content, blending ratio, doping level, and temperature. Experiments are carried out under oscillatory shear mode and with applied electric field strength varying from 0 to 2 kV/mm. Dielectric properties, conductivities are measured and correlated with the storage modulus responses. The storage modulus sensitivity, δG'G'0of the pure rubbers increases with increasing electric field strength. They attain the maximum values of about 30% and become constant at electric strength at and above 1000 V/mm.

  15. Fatigue Characteristics of 3D Printed Acrylonitrile Butadiene Styrene (ABS)

    Science.gov (United States)

    Padzi, M. M.; Bazin, M. M.; Muhamad, W. M. W.

    2017-11-01

    Recently, the use of 3D printer technology has become significant to industries, especially when involving the new product development. 3D printing is a technology, which produces the 3D product or prototype using a layer-by-layer technique. However, there becomes less research on the mechanical performance of the 3D printed component. In the present work, fatigue characteristics of 3D printed specimen have been studied. Acrylonitrile butadiene styrene (ABS) has been chosen as a material research due to its wide applications. Two types of specimen used, which is the 3D printing and moulding specimens. Fused deposition modelling (FDM) technique was used to produce the specimens. The dog bone shape part was produced based on ASTM D638 standard and the tensile test has been carried out to get the mechanical properties. Fatigue test was carried out at 40%, 60% and 80% of the tensile strength. The moulded part shows higher fatigue cycles compared to 3D printed part for all loading percentages. Fatigue lives for 40%, 60% and 80%, were 911, 2645 and 26948 cycles, respectively. The results indicated that 3D printed part has a lower fatigue life, which may not suitable for industrial applications. However, the 3D printed part could be improved by using various parameters and may be introduced in low strength application.

  16. Tungstate-induced color-pattern modifications of butterfly wings are independent of stress response and ecdysteroid effect.

    Science.gov (United States)

    Otaki, Joji M; Ogasawara, Tsuyoshi; Yamamoto, Haruhiko

    2005-06-01

    Systemic injections of sodium tungstate, a protein-tyrosine phosphatase (PTPase) inhibitor, to pupae immediately after pupation have been shown to efficiently produce characteristic color-pattern modifications on the wings of many species of butterflies. Here we demonstrated that the tungstate-induced modification pattern was entirely different from other chemically-induced ones in a species of nymphalid butterfly Junonia (Precis) orithya. In this species, the systemic injections of tungstate produced characteristic expansion of black area and shrinkage of white area together with the move of parafocal elements toward the wing base. Overall, pattern boundaries became obscure. In contrast, an entirely different modification pattern, overall darkening of wings, was observed by the injections of stress-inducing chemicals, thapsigargin, ionomycin, or geldanamycin, to pupae under the rearing conditions for the adult summer form. On the ventral wings, this darkening was due to an increase of the proportion of peppered dark scales, which was reminiscent of the natural fall form of this species. Under the same rearing conditions, the injections of ecdysteroid, which is a well-known hormone being responsible for the seasonal polyphenism of nymphalid butterflies, yielded overall expansion of orange area especially around eyespots. Taken together, we conclude that the tungstate-induced modifications are clearly distinguishable from those of stress response and ecdysteroid effect. This conclusion then suggests that the putative PTPase signaling pathway that is sensitive to tungstate uniquely contributes to the wing-wide color-pattern development in butterflies.

  17. Chrome-tanned leather shavings as a filler of butadiene-acrylonitrile rubber.

    Science.gov (United States)

    Przepiórkowska, A; Chrońska, K; Zaborski, M

    2007-03-06

    The noxious wastes from the tanning industry such as chrome-tanned leather shavings were used as the only filler of rubber mixes containing carboxylated butadiene-acrylonitrile rubber (XNBR) or butadiene-acrylonitrile rubber (NBR), and a dispersing agent Limanol PEV (Schill & Seilacher). The best form addition of leather powder to the rubber mixes is mixed the waste protein with zinc oxide. The leather powder added to the rubber mixes improves the mechanical properties: tensile strength (T(s)), elongation at break (epsilon(b)) and increase the cross-linking density of carboxylated XNBR and NBR rubber mixes. Satisfactory results of these studies are presented in this work.

  18. TupA: A Tungstate Binding Protein in the Periplasm of Desulfovibrio alaskensis G20

    Directory of Open Access Journals (Sweden)

    Ana Rita Otrelo-Cardoso

    2014-07-01

    Full Text Available The TupABC system is involved in the cellular uptake of tungsten and belongs to the ABC (ATP binding cassette-type transporter systems. The TupA component is a periplasmic protein that binds tungstate anions, which are then transported through the membrane by the TupB component using ATP hydrolysis as the energy source (the reaction catalyzed by the ModC component. We report the heterologous expression, purification, determination of affinity binding constants and crystallization of the Desulfovibrio alaskensis G20 TupA. The tupA gene (locus tag Dde_0234 was cloned in the pET46 Enterokinase/Ligation-Independent Cloning (LIC expression vector, and the construct was used to transform BL21 (DE3 cells. TupA expression and purification were optimized to a final yield of 10 mg of soluble pure protein per liter of culture medium. Native polyacrylamide gel electrophoresis was carried out showing that TupA binds both tungstate and molybdate ions and has no significant interaction with sulfate, phosphate or perchlorate. Quantitative analysis of metal binding by isothermal titration calorimetry was in agreement with these results, but in addition, shows that TupA has higher affinity to tungstate than molybdate. The protein crystallizes in the presence of 30% (w/v polyethylene glycol 3350 using the hanging-drop vapor diffusion method. The crystals diffract X-rays beyond 1.4 Å resolution and belong to the P21 space group, with cell parameters a = 52.25 Å, b = 42.50 Å, c = 54.71 Å, β = 95.43°. A molecular replacement solution was found, and the structure is currently under refinement.

  19. Investigation into interaction of mixture of zinc and neodymium nitrates with sodium tungstates in aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    Rozantsev, G M; Krivobok, V I [Donetskij Gosudarstvennyj Univ. (Ukrainian SSR)

    1978-09-01

    The methods of residual concentrations, pH-potentiometry, and conductometry have been used for studying interaction between the mixture of zinc and neodymium nitrates with sodium tungstate in aqueous solutions. It has been established that independent of the ratio between the components the reaction product is a mixture of simultaneously precipitated zinc and neodymium orthotungstates. Thermal treatment of such mixtures at 650-700 deg C for 40 h and subsequent hardening yields solid solution of the structure ..cap alpha..-Eu/sub 2/(WO/sub 4/)/sub 3/ within the concentration range 85-100 mol % of Nd/sub 2/(WO/sub 4/)/sub 3/.

  20. Synthesis and characterization of ceramic powders of pure and doped with trivalent erbium barium tungstate

    International Nuclear Information System (INIS)

    Sousa, R.B. de; Nascimento, V.A. do; Matos, J. M.E. de; Santos, M.R.M.C.

    2014-01-01

    This research proposes the synthesis and characterization of pure and doped with Er"3"+ (1 and 2 %) barium tungstate powders prepared by the coprecipitation method. In order to characterize the obtained powders were used X-Ray Diffractometry, Raman Spectroscopy and Fourier Transform Infrared Spectroscopy. According to the standard XRD spectra, the crystals exhibited the presence of tetragonal scheelite structure without the presence of secondary phases. Raman spectra showed the presence of eleven vibrational modes and two modes were observed in the infrared spectra. The synthesized oxides showed good crystallinity and structurally ordered at short and long-range. (author)

  1. Optical lines in europium-terbium double activated calcium tungstate phosphor

    Energy Technology Data Exchange (ETDEWEB)

    Nazarov, M.V. [Department of Material Science and Engineering, Korea Advanced Institute of Science and Technology, 373-1 Guseong-dong, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Tsukerblat, B.S. [Department of Chemistry, Ben-Gurion University of the Negev, 84105 Beer-Sheva (Israel)]. E-mail: tsuker@bgumail.bgu.ac.il; Popovici, E.-J. [' Raluca Ripan' Institute for Research in Chemistry, Cluj-Napoca (Romania); Jeon, D.Y. [Department of Material Science and Engineering, Korea Advanced Institute of Science and Technology, 373-1 Guseong-dong, Yuseong-gu, Daejeon 305-701 (Korea, Republic of)

    2004-09-20

    The Letter is devoted to the problem of the optical anisotropy of the rare-earth ions occupying low-symmetry positions in crystals. The crystal field multiplets arising from LSJ terms of Eu{sup 3+} and Tb{sup 3+} ions in the crystal field of calcium tungstate scheelite (CaWO{sub 4}) are analyzed with regard to the experimental data on the low temperature photoluminescence and cathodoluminescence spectra. The selection rules as well as an angular (polarization) dependence of the two-photon absorption are discussed.

  2. Synthesis and Thermal Properties of Acrylonitrile/Butyl Acrylate/Fumaronitrile and Acrylonitrile/Ethyl Hexyl Acrylate/Fumaronitrile Terpolymers as a Potential Precursor for Carbon Fiber

    OpenAIRE

    Jamil, Siti Nurul Ain Md; Daik, Rusli; Ahmad, Ishak

    2014-01-01

    A synthesis of acrylonitrile (AN)/butyl acrylate (BA)/fumaronitrile (FN) and AN/EHA (ethyl hexyl acrylate)/FN terpolymers was carried out by redox polymerization using sodium bisulfite (SBS) and potassium persulphate (KPS) as initiator at 40 °C. The effect of comonomers, BA and EHA and termonomer, FN on the glass transition temperature (Tg) and stabilization temperature was studied using Differential Scanning Calorimetry (DSC). The degradation behavior and char yield were obtained by Thermog...

  3. Influence of acrylonitrile butadiene rubber on recyclability of blends prepared from poly(vinyl chloride) and poly(methyl methacrylate).

    Science.gov (United States)

    Suresh, Sunil S; Mohanty, Smita; Nayak, Sanjay K

    2018-06-01

    The current investigation deals with the recycling possibilities of poly(vinyl chloride) and poly(methyl methacrylate) in the presence of acrylonitrile butadiene rubber. Recycled blends of poly(vinyl chloride)/poly(methyl methacrylate) are successfully formed from the plastic constituents, those are recovered from waste computer products. However, lower impact performance of the blend and lower stability of the poly(vinyl chloride) phase in the recycled blend restricts its further usage in industrial purposes. Therefore, effective utilisation acrylonitrile butadiene rubber in a recycled blend was considered for improving mechanical and thermal performance. Incorporation of acrylonitrile butadiene rubber resulted in the improvement in impact performance as well as elongation-at-break of the recycled blend. The optimum impact performance was found in the blend with 9 wt% acrylonitrile butadiene rubber, which shows 363% of enhancement as compared with its parent blend. Moreover, incorporated acrylonitrile butadiene rubber also stabilises the poly(vinyl chloride) phase present in the recycled blend, similarly Fourier transform infrared spectroscopy studies indicate the interactions of various functionalities present in the recycled blend and acrylonitrile butadiene rubber. In addition to this, thermogravimetric analysis indicates the improvement in the thermal stability of the recycled blend after the addition of acrylonitrile butadiene rubber into it. The existence of partial miscibility in the recycled blend was identified using differential scanning calorimetry and scanning electron microscopy.

  4. New Star-Branched Poly(acrylonitrile) Architectures : ATRP Synthesis and Solution Properties

    NARCIS (Netherlands)

    Pitto, Valentina; Voit, Brigitte I.; Loontjens, Ton J.A.; Benthem, Rolf A.T.M. van

    2004-01-01

    Atom transfer radical polymerization (ATRP) has been chosen as ‘‘living’’/controlled free radical polymerization system to synthesize a number of novel poly(acrylonitrile) (PAN) architectures. The reaction conditions for the synthesis of linear samples with control over molar mass and molar mass

  5. Synthesis and flocculation properties of gum ghatti andpoly(acrylamide-co-acrylonitrile) based biodegradable hydrogels

    CSIR Research Space (South Africa)

    Mittal, H

    2014-12-01

    Full Text Available This article reports the development of biodegradable flocculants based on graft co-polymers of gum ghatti (Gg) and a mixture of acrylamide and acrylonitrile co-monomers (AAm-co-AN). The hydrogel polymer exhibited an excellent swelling capacity...

  6. Dynamic Evaluation of Acrylonitrile Butadiene Styrene Subjected to High-Strain-Rate Compressive Loads

    Science.gov (United States)

    2014-12-01

    Riddick, J. C.; Hall, A. J.; Haile, M. A.; Von Wahlde, R.; Cole, D. P.; Biggs S. J. Effect of Manufacturing Parameters on Failure in Acrylonitrile...for Tensile Properties of Plastics Annu. Book ASTM Stand. 2004, 1–15. 17. Zukas, J. High Velocity Impact Dynamics; John Wiley & Sons, Inc.: New York

  7. Distribution of [1-14C]acrylonitrile in rat and monkey

    International Nuclear Information System (INIS)

    Sandberg, E.Ch.; Slanina, P.

    1980-01-01

    The distribution of [1- 14 C]acrylonitrile (ACN) in rat and monkey has been studied by whole-body autoradiography, after being administered orally and intravenously to rats and orally to monkeys. Uptake of radioactivity was seen in the blood, liver, kidney, lung, adrenal cortex and stomach mucosa. (Auth.)

  8. Dimensional accuracy of Acrylonitrile Butadiene Styrene injection molded parts produced in a pilot produc

    DEFF Research Database (Denmark)

    Mischkot, Michael; Davoudinejad, Ali; Charalambis, Alessandro

    of a geometry including micro-features have been injection-molded in Acrylonitrile Butadiene Styrene (ABS) with a single 20x20x2.5 mm^3 injection molding insert manufactured in a photopolymer composite material. This research investigates the dimensional accuracy of the injection molded parts as a function...

  9. 21 CFR 177.1040 - Acrylonitrile/styrene copoly-mer.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acrylonitrile/styrene copoly-mer. 177.1040 Section 177.1040 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as Basic Components of Single and Repeated Use Food...

  10. Double aberration-corrected TEM/STEM of tungstated zirconia nanocatalysts for the synthesis of paracetamol

    International Nuclear Information System (INIS)

    Yoshida, K; Boyes, E D; Gai, P L; Shiju, N R; Brown, D R

    2010-01-01

    We report highly active tungstated zirconia nanocatalysts for the synthesis of paracetamol by Beckmann rearrangement of 4-hydroxyacetophenone oxime. Double aberration-corrected (2AC)-TEM/STEM studies were performed in a JEOL 2200FS FEG TEM/STEM at the 1 Angstrom (1 A = 0.1 nanometer) level. Observations at close to zero defocus were carried out using the AC-TEM as well as AC-STEM including high angle annular dark field (HAADF) imaging, from the same areas of the catalyst crystallites. The studies from the same areas have revealed the location and the nanostructure of the polytungstate species (clusters) and the nanograins of zirconia. The AC (S)TEM was crucial to observe the nanostructure and location of polytungstate clusters on the zirconia grains. Polytungstate clusters as small as 0.5 nm have been identified using the HAADF-STEM. The nanostructures of the catalyst and the W surface density have been correlated with paracetamol reaction studies. The results demonstrate the nature of active sites and high activity of the tungstated zirconia nanocatalyst, which is an environmentally clean alternative to the current homogeneous process.

  11. Double aberration-corrected TEM/STEM of tungstated zirconia nanocatalysts for the synthesis of paracetamol

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, K; Boyes, E D; Gai, P L [York JEOL Nanocentre (United Kingdom); Shiju, N R; Brown, D R, E-mail: pgb500@york.ac.u [Department of Chemical and Biological Sciences, University of Huddersfield, Huddersfield, HD1 3DH (United Kingdom)

    2010-07-01

    We report highly active tungstated zirconia nanocatalysts for the synthesis of paracetamol by Beckmann rearrangement of 4-hydroxyacetophenone oxime. Double aberration-corrected (2AC)-TEM/STEM studies were performed in a JEOL 2200FS FEG TEM/STEM at the 1 Angstrom (1 A = 0.1 nanometer) level. Observations at close to zero defocus were carried out using the AC-TEM as well as AC-STEM including high angle annular dark field (HAADF) imaging, from the same areas of the catalyst crystallites. The studies from the same areas have revealed the location and the nanostructure of the polytungstate species (clusters) and the nanograins of zirconia. The AC (S)TEM was crucial to observe the nanostructure and location of polytungstate clusters on the zirconia grains. Polytungstate clusters as small as 0.5 nm have been identified using the HAADF-STEM. The nanostructures of the catalyst and the W surface density have been correlated with paracetamol reaction studies. The results demonstrate the nature of active sites and high activity of the tungstated zirconia nanocatalyst, which is an environmentally clean alternative to the current homogeneous process.

  12. Study on preparation of ultrafine lead tungstate for radiation protection and γ-ray shielding of the gloves

    International Nuclear Information System (INIS)

    Du Licheng; He Ping; Zhou Yuanlin; Song Kaiping; Yang Kuihua

    2012-01-01

    Lead tungstate combines the radiation shielding properties of tungsten and lead, and it is quite distinctive to manufacture lead tungstate with ultra-fine granularity to enhance its capacity of radiation shielding. The grain size of lead tungstate has direct impact on the ability of its protection from radioactive materials. the smaller the grain size and more uniform dispersion of lead tungstate, the better protective ability it is going to be. In this paper, soft-template synthesis was introduced to prepare ultra-fine PbWO 4 . Rigorous experiment conditions are settled to ensure the access to obtain ultra-fine, homogeneous lead tungstate product, and it is better than other physical and chemical preparation methods. The surface-active agent for the soft template, with S-60 for the water system W/O microemulsion zone, was used to synthesize successfully ultra-fine PbWO 4 . It was shown that dispersing agent S-60 in the soft template method produced ultra-fine PbWO 4 with uniform granularity distribution. By using orthogonal experimental method, the best experimental conditions were obtained as follows: S-60 as surfactant dispersant with diluted 30 times concentration, solutions with pH9, 0.01 mol/L concentration of reactant, 1300 rpm of stirring speed and slowly adding drops of Na 2 WO 4 solution into Pb (Ac) 2 solution. Based on the optimal experimental conditions, the product of ultra-fine product for the anti-radiation protection filler has been made. The fine packing for the preparation of tungsten the gamma rays on the gloves is an average capacity of 5% or so. (authors)

  13. Vanadia-based SCR Catalysts Supported on Tungstated and Sulfated Zirconia: Influence of Doping with Potassium

    DEFF Research Database (Denmark)

    Due-Hansen, Johannes; Boghosian, Soghomon; Kustov, Arkadii

    2007-01-01

    A series of vanadium-based SCR catalysts supported on sulfated or tungstated ZrO2 were synthesized and characterized by means of N2-BET, XRD, NH3-TPD and in situ Raman spectroscopy. The effect of potassium doping on the properties of vanadia species is studied in detail. A number of catalyst...... and morphology, the surface composition and the molecular configuration of the dispersed vanadates. It was observed that poisoning with potassium had a negligible effect on the surface vanadate species (especially the V=O stretching frequency observed by in situ Raman spectroscopy) if supported on the sulfated...... the observed decrease in V=O stretching frequency and the higher proportion of dimers and higher polymers through coordination between K+ and two neighbouring V=O. The results suggest an increased resistance towards potassium doping for the vanadia-based catalysts supported on sulfated zirconia....

  14. Synthesis and characterization of rare-earth-doped calcium tungstate nanocrystals

    Science.gov (United States)

    Suneeta, P.; Rajesh, Ch.; Ramana, M. V.

    2018-02-01

    In this paper, we report synthesis and characterization of rare-earth-ion-doped calcium tungstate (CaWO4) nanocrystals (NCs). Rare-earth ions, such as gadolinium (Gd), neodymium (Nd), praseodymium (Pr), samarium (Sm) and holmium (Ho), were successfully doped in the CaWO4 NCs by changing the synthesis conditions. The adopted synthesis route was found to be fast and eco-friendly. Structural characterizations, such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and compositional analysis, were performed using energy dispersive analysis of X-rays (EDAX) on as-synthesized NCs. The results indicate the size of the NCs ranging between 47 to 68nm and incorporation of rare-earth ions in CaWO4 NCs.

  15. Tungstated zirconia as promising carrier for DeNOx catalysts with improved resistance towards alkali poisoning

    DEFF Research Database (Denmark)

    Due-Hansen, Johannes; Kustov, Arkadii; Rasmussen, Søren Birk

    2006-01-01

    Use of biomass as an alternative to fossil fuels has achieved increasing interest since it is considered neutral regarding CO2 accumulation in the atmosphere. The by far most energy-efficient use of solid bio-resources in energy production is combustion in combined biomass and coal or oilfired...... of new alternative catalysts that are more resistant towards poisoning with potassium. Vanadia-based catalysts supported on traditional and tungstated zirconia has been prepared and tested in selective catalytic reduction of NO with ammonia. All prepared catalysts were characterized using N2-BET, XRD......, and NH3-TPD methods. The influence of calcination temperature of zirconia modified with tungsten oxide on the textural characteristics, acidity and catalytic performance was studied. The resistance of the catalysts towards model poisoning with potassium was found to depend dramatically...

  16. Synthesis of gels with basis of titanium tungstates as matrixes of radioactive generators

    International Nuclear Information System (INIS)

    Galico C, L.

    2005-01-01

    The heteropolyanions, compounds formed by the union of molybdates or tungstates polyanions with atoms of metals like zirconium, titanium, cerium, thorium, tin, etc., have been used as generator matrixes of 99m Tc or 188 Re. Particularly they have been studied and produced successfully in our laboratory, generators of 99 Mo/ 99 m Tc at basis of gels zirconium molybdates and titanium molybdates. Considering that the molybdenum and tungsten, as well as the technetium and the rhenium, its belong to the same groups of transition metals, it is feasible that gels can be synthesized at basis of titanium tungstates, continuing a methodology similar to that of the gels titanium molybdates or zirconium molybdates, to produce generators 188 W/ 188 Re. The 188 Re possess nuclear characteristics that make it attractive for therapeutic applications, since, it emits β - particles of a great energy (2.12 MeV); joined to the possibility of being able to unite to different ligands (bifunctional agents) and biomolecules (antibodies or fragments of proteins), as it makes the 99m Tc, useful in radioimmunotherapy. Commercially the 188 Re generators use a chromatographic column loaded with alumina where the 188 Re, it is adsorbed and eluted the 188 ReO 4 - by means of a saline solution The alumina adsorbs around 0.2% of the 188 Re, situation that forces to use 188 Re of a high specific activity. The use of the gels technology, allows to work with medium or low specific activities of 188 Re, opening the possibility of their production in countries whose nuclear capacity is medium or low. In particular, the synthesized gels with basis of titanium offer the possibility of being synthesized with non active material, for later on to be irradiated and directly produce the generator, since, the titanium 51 Ti, unique radioisotope produced by the titanium, has a half life of 5.79 min. This synthesis method avoids the manipulation of radioactive material during the synthesis of the gels, process

  17. Integrated lasers in crystalline double tungstates with focused-ion-beam nanostructured photonic cavities

    International Nuclear Information System (INIS)

    Ay, F; Iñurrategui, I; Geskus, D; Aravazhi, S; Pollnau, M

    2011-01-01

    Deeply etched Bragg gratings were fabricated by focused ion beam (FIB) milling in KGd x Lu 1-x (WO 4 ) 2 :Yb 3+ to obtain photonic cavity structures. By optimizing parameters such as dose per area, dwell time and pixel resolution the redeposition effects were minimized and grating structures more than 4 μm in depth with an improved sidewall angle of ∼ 5° were achieved. Fabry-Perot microcavities were defined and used to assess the optical performance of the grating structures at ∼ 1530 nm. An on-chip integrated laser cavity at ∼ 980 nm was achieved by defining a FIB reflective grating and FIB polished waveguide end-facet. With this cavity, an on-chip integrated waveguide laser in crystalline potassium double tungstate was demonstrated

  18. Experimental Study of the Lead Tungstate Scintillator Proton-Induced Damage and Recovery

    CERN Document Server

    Auffray, Etiennette; Singovski , A

    2011-01-01

    Lead tungstate (PbWO4, or PWO) scintillating crystals are used by two of the four experiments at the Large Hadron Collider (LHC): 75848 in CMS and 17920 in ALICE. For the CMS electromagnetic calorimeter, one of the most important crystal properties is its radiation hardness. With the increase of luminosity, the radiation level will increase drastically, particularly in the high pseudorapidity regions of the calorimeter. Beside the effects of color-centre formation caused by gamma-radiation, additional measurable effect originated by hadron irradiation could appear, which will further deteriorate the optical transmission of the crystals and therefore their efficiency. In this paper, we will present results of the proton-induced damage in PWO and a study of optical transmission recovery at different temperatures and under different light-induced "bleaching" conditions for proton-irradiated crystals.

  19. Improvement of several properties of lead tungstate crystals with different doping ions

    CERN Document Server

    Auffray, Etiennette; Baccaro, Stefania; Cecilia, Angelica; Dafinei, Ioan; Diemoz, Marcella; Jarolímek, O; Korzhik, Mikhail; Lecoq, Paul; Nikl, M

    1998-01-01

    A very good radiation resistance of Lead Tungstate crystals is mandatory for their use in the high precision electromagnetic calorimeter of the CMS experiment at LHC. Since the beginning of 1996 we have organised systematic investigations of the parameters influencing the radiation hardness of this crystal. Two classes of parameters have been particularly studied, the first one related to the control of the stoichiometry and structure associated defects, the second one connected with the suppression and the charge compensation of existing defects with different kinds of doping ions. This paper reports about the second part of this study and complements a first paper where the role of the stoichiometry was already discussed. Results of tests are given on a significant statistical sample of full size crystals ( 23cm) which show a considerable improvement in the optical properties and the radiation resistance of appropriately doped crystals.

  20. Scintillation of lead tungstate crystal studied with single-electron beam from KUFEL

    Energy Technology Data Exchange (ETDEWEB)

    Rizwan, Mohamad, E-mail: rizwan@nucl.kyushu-u.ac.jp; Uozumi, Yusuke; Matsuo, Kazuki [Department of Applied Quantum Physics and Nuclear Engineering, Kyushu University, Fukuoka (Japan); Ohgaki, Hideaki; Kii, Toshiteru; Zen, Heishun [Institute of Advanced Energy, Kyoto University, Gokasho, Uji, Kyoto (Japan); Tsamalaidze, Zviadi; Evtoukhovitch, Petr; Valentin, Samoilov [Joint Institute for Nuclear Research, JINR, Joliot-Curie Str.6, Dubna (Russian Federation)

    2015-04-29

    Lead tungstate (PWO) crystal has a very fast response, high atomic density and high radiation hardness. Therefore, they are suitable to be used for high-energy nuclear data measurements under high-background circumstances. Although a good electron-ion separation with a pulse shape analysis technique is essential, scintillation pulse shapes have not been observed with electron beams of a wide energy range. A single-electron beam technique has been developed at Kyoto University Free Electron Laser (KUFEL), and electron beams of 4-38 MeV are available. During the experiments, single electron beams bombarded a PWO crystal. By using oscilloscope we observed scintillation pulses of a PWO crystal coupled with a photomultiplier tube. Measured spectra were compared with the simulation code of EGS5 to analyze scattering effects. As the result, the pulse amplitudes show good linearity and the pulse shapes are almost constant in the observed energy range.

  1. Monitoring light source for CMS lead tungstate crystal calorimeter at LHC

    CERN Document Server

    Zhang Li Yuan; Zhu Ren Yuan; Liu Dun Can

    2000-01-01

    Light monitoring will serve as an inter calibration for CMS lead tungstate crystals in situ at LHC, which is crucial for maintaining crystal calorimeter's sub percent constant term in the energy resolution. This paper presents the design of the CMS ECAL monitoring light source and high level distribution system. The correlations between variations of the light output and the transmittance for the CMS choice of Y doped PbWO//4 crystals were investigated, and were used to study monitoring linearity and sensitivity as a function of the wavelength. The monitoring wavelength was determined so that a good linearity as well as adequate sensitivity can be achieved. The performance of a custom manufactured tunable laser system is presented. Issues related to monitoring precision are discussed. 29 Refs.

  2. Monitoring light source for CMS lead tungstate crystal calorimeter at LHC

    CERN Document Server

    Zhang Liang Ying; Zhu, R Y; Liu, D T

    2001-01-01

    Light monitoring will serve as an intercalibration for Compact Muon Solenoid (CMS) lead tungstate crystals in situ at the Large Hadronic Collider, which is crucial for maintaining crystal calorimeter's subpercent constant term in the energy resolution. This paper presents the design of the CMS electromagnetic calorimeter monitoring light source and high-level distribution system. The correlations between variations of the light output and the transmittance for the CMS choice of yttrium-doped PbWO/sub 4/ crystals were investigated and were used to study monitoring linearity and sensitivity as a function of wavelength. The monitoring wavelength was determined so that a good linearity as well as adequate sensitivity can be achieved. The performance of a custom manufactured tunable laser system is presented. Issues related to monitoring precision are discussed. (12 refs).

  3. Properties of complex tungstates, niobates, translated with fluorite-like structure

    International Nuclear Information System (INIS)

    Vetkina, S.N.; Zolin, V.F.; Sirotinkin, V.P.; Smirnov, S.A.

    1989-01-01

    Spectra of ternary tungstates, niobates and tantalates (MeLa 2 WO 7 , La 3 TO 7 ; Me=Ba, Sr; T=Ta, Nb) related to the layered fluorite group are analyzed. The laser pumping and time resolved luminescence are used for selecting spectra of unequivalent centers. The symmetry of the first center is near to the distorted cubic one. The vibrational spectra of europium in Eu 3 NbO 7 and SrLa 2 WO 7 are due to the chain-like structure of niobates and to the net-like structure of tantalates. The stimulated emission of Nd 3+ in powders of BaLa 2 WO 7 and La 3 NbO 7 is observed at wavelengths of 1.07 and 1.063 μm, respectively

  4. Reduction of tungstates and molybdates by hydrogen and thermodynamic properties of these salts

    International Nuclear Information System (INIS)

    Gerasimov, Ya.I.; Rezukhina, T.N.; Simanov, Yu.P.; Vasil'eva, I.A.; Kurshakova, R.D.

    1988-01-01

    Study of thermodynamic properties of a series of tungstates of bivalent metals (Mg, Ca, Sr, Ba, Mn, Co, Fe, Ni, Cu, Zn, Cd and Pb) as well as of some molybdates- of Mg, Ca, Sr, Ba is carried out. The obtained values are compared with magnetic characteristics of compounds and parameters of their crystal lattices. Thermodynamic properties were studied by measuring constants of their reduction with hydrogen in the 500-1350 deg C temperature range. It is concluded that dependence of thermodynamic values on geometric parameters of the lattice is not definitive. Comparison of salt formation atomic entropies with deviations of salt magnetic moments from theoretical ionic moments points to the fact of existence of some accordance between these two series of values. 25 refs.; 10 figs.; 6 tabs

  5. Synthesis and Characterization of Tin (IV Tungstate Nanoparticles – A Solid Acid Catalyst

    Directory of Open Access Journals (Sweden)

    Manoj Sadanandan

    2012-12-01

    Full Text Available Tin (IV tungstate, a tetravalent metal acid salt was synthesized in the nanoform by chemical coprecipitation method using EDTA as capping agent. The material was found to be stable in mineral acids, bases and organic solvents except  in HF and aquaregia. The material was characterized using EDS, TG/DTA, FTIR, XRD, SEM, HRTEM and BET surface area measurement. The molecular formula of the compound is 2SnO2 3WO3.5H2O determined from elemental analysis using TG/DTA. Surface morphology and particle size were obtained using SEM and HRTEM. The surface area was found to be 205-225m2/g. The Na+ exchange capacity found to be 3.8 meq/g, indicates the presence of surface hydroxyl group and hence the presence of Bronsted acid sites. The catalytic activity of the material was tested by using esterification and oxidation as model reactions. For the esterification of different alcohols, the percentage yield was found to be high for n-alcohol compared to isomeric alcohols. Oxidation of benzyl alcohol gives benzaldehyde and benzoic acid as the only products. Copyright © 2012 by BCREC UNDIP. All rights reservedReceived: 12nd June 2012, Revised: 23rd July 2012, Accepted: 29th July 2012[How to Cite: S. Manoj, R. Beena, (2012. Synthesis and Characterization of tin(IV Tungstate Nanoparticles – A Solid Acid Catalyst. Bulletin of Chemical Reaction Engineering & Catalysis, 7 (2: 105-111. doi:10.9767/bcrec.7.2.3622.105-111] [How to Link / DOI: http://dx.doi.org/10.9767/bcrec.7.2.3622.105-111 ] | View in 

  6. Novel rattling of K atoms in aluminium-doped defect pyrochlore tungstate

    International Nuclear Information System (INIS)

    Shoko, Elvis; Kearley, Gordon J; Peterson, Vanessa K; Thorogood, Gordon J; Mutka, Hannu; Koza, Michael M; Yamaura, Jun-ichi; Hiroi, Zenji

    2014-01-01

    Rattling dynamics have been identified as fundamental to superconductivity in defect pyrochlore osmates and aluminium vanadium intermetallics, as well as low thermal conductivity in clathrates and filled skutterudites. Combining inelastic neutron scattering (INS) measurements and ab initio molecular dynamics (MD) simulations, we use a new approach to investigate rattling in the Al-doped defect pyrochlore tungstates: AAl 0.33 W 1.67 O 6 (A = K, Rb, Cs). We find that although all the alkali metals rattle, the rattling of the K atoms is unique, not only among the tungstates but also among the analogous defect osmates, KOs 2 O 6 and RbOs 2 O 6 . Detailed analysis of the MD trajectories reveals that two unique features set the K dynamics apart from the rest, namely, (1) quasi one-dimensional local diffusion within a cage, and (2) vibration at a range of frequencies. The local diffusion is driven by strongly anharmonic local potentials around the K atoms exhibiting a double-well structure in the direction of maximum displacement, which is also the direction of local diffusion. On the other hand, vibration at a range of frequencies is a consequence of the strong anisotropy in the local potentials around the K atoms as revealed by directional magnitude spectra. We present evidence to show that it is the smaller size rather than the smaller mass of the K rattler which leads to the unusual dynamics. Finally, we suggest that the occurrence of local diffusion and vibration at a range of frequencies in the dynamics of a single rattler, as found here for the K atoms, may open new possibilities for phonon engineering in thermoelectric materials. (paper)

  7. Tungstate-based glass-ceramics for the immobilization of radio cesium

    Science.gov (United States)

    Drabarek, Elizabeth; McLeod, Terry I.; Hanna, John V.; Griffith, Christopher S.; Luca, Vittorio

    2009-02-01

    The preparation of tungstate-containing glass-ceramic composites (GCC) for the potential immobilization of radio cesium has been considered. The GCC materials were prepared by blending two oxide precursor compositions in various proportions. These included a preformed Cs-containing hexagonal tungsten bronze (HTB) phase (Cs 0.3Ti 0.2W 0.8O 3, P6 3/ mcm) and a blend of silica and other oxides. The use of the HTB phase was motivated on the assumption that a HTB-based adsorbent could be used to remove cesium directly from aqueous high level liquid waste feeds. In the absence of the HTB, glass-ceramics were relatively easily prepared from the Cs-containing glass-forming oxide blend. On melting the mixture a relative complex GCC phase assemblage formed. The principal components of this phase assemblage were determined using X-ray powder diffraction, 133Cs MAS-NMR, and cross-sectional SEM and included glass, various zeolites, scheelite (CaWO 4) and a range of other oxide phases and Cs-containing aluminosilicate. Importantly, under no circumstance was cesium partitioned into the glass phase irrespective of whether or not the composition included the preformed Cs-containing HTB compound. For compositions containing the HTB, cesium was partitioned into one of four major phases including zeolite; Cs-silica-tungstate bronze, pollucite (CsAlSi 2O 6), and an aluminosilicate with an Al/Si ratio close to one. The leach resistance of all materials was evaluated and related to the cesium distribution within the GCC phase assemblages. In general, the GCCs prepared from the HTB had superior durability compared with materials not containing tungsten. Indeed the compositions in many cases had leach resistances comparable to the best ceramics or glass materials.

  8. Preparation of poly(acrylonitrile-butyl acrylate) gel electrolyte for lithium-ion batteries

    International Nuclear Information System (INIS)

    Tian Zheng; He Xiangming; Pu Weihua; Wan Chunrong; Jiang Changyin

    2006-01-01

    Poly(acrylonitrile-butyl acrylate) gel polymer electrolyte was prepared for lithium ion batteries. The preparation started with synthesis of poly(acrylonitrile-butyl acrylate) by radical emulsion polymerization, followed by phase inversion to produce microporous membrane. Then, the microporous gel polymer electrolytes (MGPEs) was prepared with the microporous membrane and LiPF 6 in ethylene carbonate/diethyl carbonate. The dry microporous membrane showed a fracture strength as high as 18.98 MPa. As-prepared gel polymer electrolytes presented ionic conductivity in excess of 3.0 x 10 -3 S cm -1 at ambient temperature and a decomposition voltage over 6.6 V. The results showed that the as-prepared gel polymer electrolytes were promising materials for Li-ion batteries

  9. Preparation and characterization of zinc sulphide nanocomposites based on acrylonitrile butadiene rubber

    Science.gov (United States)

    Ramesan, M. T.; Nihmath, A.; Francis, Joseph

    2013-06-01

    Rubber composite based on acrylonitrile butadiene rubber (NBR) reinforced with nano zinc sulphide (ZnS) have been prepared via vulcanization process and characterized by several techniques. Processing characteristics such as scorch time, optimum cure time decreases with increase in concentration of nano filler in acrylonitrile butadiene rubber. Mechanical properties such as tensile and tear strength increases with increase in concentration of nano filler up to 7 phr of loading thereafter the value decreases, whereas hardness, and flame resistance increases with the dosage of fillers. These enhanced properties are due to the homogenous dispersion of nano fillers in NBR matrix, which is evidenced from the structure that evaluated using X-ray diffraction (XRD) and scanning electron microscopy (SEM).

  10. Synthesis and Characterization of Solution and Melt Processible Poly(Acrylonitrile-Co-Methyl Acrylate) Statistical Copolymers

    Science.gov (United States)

    Pisipati, Padmapriya

    Polyacrylonitrile (PAN) and its copolymers are used in a wide variety of applications ranging from textiles to purification membranes, packaging material and carbon fiber precursors. High performance polyacrylonitrile copolymer fiber is the most dominant precursor for carbon fibers. Synthesis of very high molecular weight poly(acrylonitrile-co-methyl acrylate) copolymers with weight average molecular weights of at least 1.7 million g/mole were synthesized on a laboratory scale using low temperature, emulsion copolymerization in a closed pressure reactor. Single filaments were spun via hybrid dry-jet gel solution spinning. These very high molecular weight copolymers produced precursor fibers with tensile strengths averaging 954 MPa with an elastic modulus of 15.9 GPa (N = 296). The small filament diameters were approximately 5 im. Results indicated that the low filament diameter that was achieved with a high draw ratio, combined with the hybrid dry-jet gel spinning process lead to an exponential enhancement of the tensile properties of these fibers. Carbon fibers for polymer matrix composites are currently derived from polyacrylonitrile copolymer fiber precursors where solution spinning accounts for ˜40 % of the total fiber production cost. To expand carbon fiber applications into the automotive industry, the cost of the carbon fiber needs to be reduced from 8 to ˜3-5. In order to develop an alternative melt processing route several benign plasticizers have been investigated. A low temperature, persulfate-metabisulfite initiated emulsion copolymerization was developed to synthesize poly(acrylonitrile-co-methyl acrylate) copolymers with acrylonitrile contents between 91-96 wt% with a molecular weight range of 100-200 kg/mol. This method was designed for a potential industrial scale up. Furthermore, water was investigated as a potential melting point depressant for these copolymers. Twenty-five wt% water lead to a decrease in the Tm of a 93/7 wt/wt % poly(acrylonitrile

  11. Preparation of poly(acrylonitrile-butyl acrylate) gel electrolyte for lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Tian Zheng [Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China); He Xiangming [Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China)]. E-mail: hexm@tsinghua.edu.cn; Pu Weihua [Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China); Wan Chunrong [Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China); Jiang Changyin [Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China)

    2006-10-25

    Poly(acrylonitrile-butyl acrylate) gel polymer electrolyte was prepared for lithium ion batteries. The preparation started with synthesis of poly(acrylonitrile-butyl acrylate) by radical emulsion polymerization, followed by phase inversion to produce microporous membrane. Then, the microporous gel polymer electrolytes (MGPEs) was prepared with the microporous membrane and LiPF{sub 6} in ethylene carbonate/diethyl carbonate. The dry microporous membrane showed a fracture strength as high as 18.98 MPa. As-prepared gel polymer electrolytes presented ionic conductivity in excess of 3.0 x 10{sup -3} S cm{sup -1} at ambient temperature and a decomposition voltage over 6.6 V. The results showed that the as-prepared gel polymer electrolytes were promising materials for Li-ion batteries.

  12. Radical copolymerization in homogenous medium and emulsion system monomers acrylonitrile/styrene

    Directory of Open Access Journals (Sweden)

    Boussehel H.

    2013-09-01

    Full Text Available This study examines the radical copolymerization in homogeneous and emulsion of the monomer system acrylonitrile/styrene. These copolymers are of great interest to the plastics industry, because they combine the good mechanical properties and implementation provided by the styrene units in the very high solvent resistance and extreme gas impermeability provided by the acrylonitrile units. The properties of a copolymer are directly related to its composition and distribution of monomer units in its macromolecular chains. Based on the reports of the couple reactivity's of monomers (AN/S found in the literature, the objective of the work is to provide theoretical simulation (by analytical and numerical integration of the equation of copolymerization: The kinetics of the reaction copolymerization of AN/S in a homogeneous medium and emulsion (drift composition, azeotropic and the microstructure (distribution of monomer sequences and the glass transition property of the macromolecular chains instant formed throughout the copolymerization reaction.

  13. Detection of acrolein and acrylonitrile with a pulsed room temperature quantum cascade laser

    Science.gov (United States)

    Manne, J.; Jäger, W.; Tulip, J.

    2010-06-01

    We investigated the use of a pulsed, distributed feedback quantum cascade laser centered at 957 cm-1 in combination with an astigmatic Herriot cell with 250 m path length for the detection of acrolein and acrylonitrile. These molecules have been identified as hazardous air-pollutants because of their adverse health effects. The spectrometer utilizes the intra-pulse method, where a linear frequency down-chirp, that is induced when a top-hat current pulse is applied to the laser, is used for sweeping across the absorption line. Up to 450 ns long pulses were used for these measurements which resulted in a spectral window of ~2.2 cm-1. A room temperature mercury-cadmium-telluride detector was used, resulting in a completely cryogen free spectrometer. We demonstrated detection limits of ~3 ppb for acrylonitrile and ~6 ppb for acrolein with ~10 s averaging time. Laser characterization and optimization of the operational parameters for sensitivity improvement are discussed.

  14. The surface reactivity of acrylonitrile with oxygen atoms on an analogue of interstellar dust grains

    Science.gov (United States)

    Kimber, Helen J.; Toscano, Jutta; Price, Stephen D.

    2018-06-01

    Experiments designed to reveal the low-temperature reactivity on the surfaces of interstellar dust grains are used to probe the heterogeneous reaction between oxygen atoms and acrylonitrile (C2H3CN, H2C=CH-CN). The reaction is studied at a series of fixed surface temperatures between 14 and 100 K. After dosing the reactants on to the surface, temperature-programmed desorption, coupled with time-of-flight mass spectrometry, reveals the formation of a product with the molecular formula C3H3NO. This product results from the addition of a single oxygen atom to the acrylonitrile reactant. The oxygen atom attack appears to occur exclusively at the C=C double bond, rather than involving the cyano(-CN) group. The absence of reactivity at the cyano site hints that full saturation of organic molecules on dust grains may not always occur in the interstellar medium. Modelling the experimental data provides a reaction probability of 0.007 ± 0.003 for a Langmuir-Hinshelwood style (diffusive) reaction mechanism. Desorption energies for acrylonitrile, oxygen atoms, and molecular oxygen, from the multilayer mixed ice their deposition forms, are also extracted from the kinetic model and are 22.7 ± 1.0 kJ mol-1 (2730 ± 120 K), 14.2 ± 1.0 kJ mol-1 (1710 ± 120 K), and 8.5 ± 0.8 kJ mol-1 (1020 ± 100 K), respectively. The kinetic parameters we extract from our experiments indicate that the reaction between atomic oxygen and acrylonitrile could occur on interstellar dust grains on an astrophysical time-scale.

  15. Innovative Application of Biopolymer Keratin as a Filler of Synthetic Acrylonitrile-Butadiene Rubber NBR

    OpenAIRE

    Prochoń, Mirosława; Przepiórkowska, Anita

    2013-01-01

    The current investigations show the influence of keratin, recovered from the tanning industry, on the thermal and mechanical properties of vulcanizates with synthetic rubber acrylonitrile-butadiene rubber NBR. The addition of waste protein to NBR vulcanizates influences the improvement of resistance at high temperatures and mechanical properties like tensile strength and hardness. The introduction of keratin to the mixes of rubber previously blended with zinc oxide (ZnO) before vulcanization ...

  16. Degradation of acrylonitrile butadiene rubber and fluoroelastomers in rapeseed biodiesel and hydrogenated vegetable oil

    OpenAIRE

    Akhlaghi, Shahin

    2017-01-01

    Biodiesel and hydrotreated vegetable oil (HVO) are currently viewed by the transportation sector as the most viable alternative fuels to replace petroleum-based fuels. The use of biodiesel has, however, been limited by the deteriorative effect of biodiesel on rubber parts in automobile fuel systems. This work therefore aimed at investigating the degradation of acrylonitrile butadiene rubber (NBR) and fluoroelastomers (FKM) on exposure to biodiesel and HVO at different temperatures and oxygen ...

  17. Design and Testing of Digitally Manufactured Paraffin Acrylonitrile-Butadiene-Styrene Hybrid Rocket Motors

    OpenAIRE

    McCulley, Jonathan M.

    2013-01-01

    This research investigates the application of additive manufacturing techniques for fabricating hybrid rocket fuel grains composed of porous Acrylonitrile-butadiene-styrene impregnated with paraffin wax. The digitally manufactured ABS substrate provides mechanical support for the paraffin fuel material and serves as an additional fuel component. The embedded paraffin provides an enhanced fuel regression rate while having no detrimental effect on the thermodynamic burn properties of the fuel g...

  18. Investigation of magnetic nanoparticles in acrylonitrile-methyl methacrylate-divinylbenzene mesoporous template

    Energy Technology Data Exchange (ETDEWEB)

    Rabelo, D. E-mail: denilson@quimica.ufg.br; Lima, E.C.D.; Barbosa, D.P.; Silva, V.J.; Silva, O.; Azevedo, R.B.; Silva, L.P.; Lemos, A.P.C.; Morais, P.C

    2002-11-01

    Preparation and characterization of nanosized magnetic particles using alkaline oxidation of ferrous ion retained in acrylonitrile-methyl methacrylate-divinylbenzene (AN-MMA-DVB) spherical micron-sized polymer template is described. Atomic absorption, transmission electron microscopy and magnetic resonance were used to investigate chemically cycled nanoparticle-based composites. The resonance field shifts towards higher values as the nanoparticle concentration reduces in the polymeric template, following two very distinct regimes.

  19. Recovery of recycled acrylonitrile-butadiene-styrene, through mixing with styrene-ethylene/butylene-styrene

    OpenAIRE

    Peydro, M. A.; Parres, F.; Crespo Amorós, José Enrique; Navarro Vidal, Raúl

    2013-01-01

    Recovery of recycled acrylonitrile-butadiene-styrene (ABS) through mixing with styrene-ethylene/butylene-styrene (SEBS) has been studied in this paper. To simulate recycled ABS, virgin ABS was processed through 5 cycles, at extreme processing temperatures, 220 degrees C and 260 degrees C. The virgin ABS, the virgin SEBS, the recycled ABS and the mixtures were mechanically, thermally and rheologically characterized after the various cycles of reprocessing in order to evaluate their correspondi...

  20. Electromechanical responses of poly(3-thiopheneacetic acid/acrylonitrile-butadiene rubbers

    Directory of Open Access Journals (Sweden)

    2008-12-01

    Full Text Available Acrylonitrile-butadiene rubber (NBR and blends of poly(3-thiopheneacetic acid/ acrylonitrile-butadiene rubber, P3TAA/NBR, were fabricated, and the electrorheological properties, dielectric, and electrical conductivities were investigated . The electrorheological properties were determined under an oscillatory shear mode in a frequency range of 0.1 to 100 rad/s at various electric field strengths, from 0 to 2 kV/mm, at a fixed 27°C to observe the effects of acrylonitrile content (ACN in the rubber systems and the conductive particle concentration in the blends. For the pure rubber systems, the storage modulus response (ΔG′ is linearly dependent on its dielectric constant (ε′, and increases with the ACN content. For the NBR/P3TAA blends, the storage modulus response varies nonlinearly with the dielectric constant. The bending responses of the rubbers and the blends were investigated in a vertical cantilever fixture. For the pure rubber system, the bending angle and the dielectrophoresis force vary linearly with electric field strength. For the blend system, the bending angle and the dielectrophoresis force vary nonlinearly with electric field strength.

  1. Stepwise mechanism of oxidative ammonolysis of propane to acrylonitrile over gallium-antimony oxide catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Osipova, Z.G.; Sokolovskii, V.D.

    1979-03-01

    The stepwise mechanism of oxidative ammonolysis of propane to acrylonitrile over gallium-antimony oxide catalysts GaSb/sub 19/O/sub x/, GaSb/sub 3/Ni/sub 1.5/0/sub x/, and GaSb/sub 2.5/Ni/sub 1.5/PW/sub 0//sub 0.25/O/sub x/ was studied at 450/sup 0/ and 550/sup 0/C by introducing alternating pulses of 0.5Vertical Bar3< propane/0.6Vertical Bar3< ammonia/helium (to reduce the steady-state catalytic surface) and 0.5Vertical Bar3< propane/0.6Vertical Bar3< ammonia/1.86Vertical Bar3< oxygen/helium mixtures into a fluidized-bed catalytic reactor. Over all the catalysts studied, the rates of acrylonitrile formation during the two types of pulses were very similar, but carbon dioxide was formed much faster during the reducing pulses, particularly at 450/sup 0/C. These findings suggested that acrylonitrile is formed by a stepwise redox mechanism involving consecutive interaction of propane and ammonia with the surface oxygen of the catalysts and oxidation of the reduced catalyst surface by gas-phase oxygen. The formation of carbon dioxide proceeds by both stepwise and associative mechanisms, the latter being more important at higher temperatures. The results are similar to published results for ammoxidation of propylene and olefins.

  2. Correlation of beam electron and LED signal losses under irradiation and long-term recovery of lead tungstate crystals

    International Nuclear Information System (INIS)

    Batarin, V.A.; Butler, J.; Davidenko, A.M.; Derevschikov, A.A.; Goncharenko, Y.M.; Grishin, V.N.; Kachanov, V.A.; Konstantinov, A.S.; Kravtsov, V.I.; Kubota, Y.; Lukanin, V.S.; Matulenko, Y.A.; Melnick, Y.M.; Meschanin, A.P.; Mikhalin, N.E.; Minaev, N.G.; Mochalov, V.V.; Morozov, D.A.; Nogach, L.V.; Ryazantsev, A.V.; Semenov, P.A.; Semenov, V.K.; Shestermanov, K.E.; Soloviev, L.F.; Stone, S.; Uzunian, A.V.; Vasiliev, A.N.; Yakutin, A.E.; Yarba, J.

    2005-01-01

    Radiation damage in lead tungstate crystals reduces their transparency. The calibration that relates the amount of light detected in such crystals to incident energy of photons or electrons is of paramount importance to maintaining the energy resolution the detection system. We report on tests of lead tungstate crystals, read out by photomultiplier tubes, exposed to irradiation by monoenergetic electron or pion beams. The beam electrons themselves were used to measure the scintillation light output, and a blue light emitting diode (LED) was used to track variations of crystals transparency. We report on the correlation of the LED measurement with radiation damage by the beams and also show that it can accurately monitor the crystal recovery from such damage

  3. Solvent-Free Biginelli Condensation using Tungstate Sulfuric Acid: a Powerful and Reusable Catalyst for Selective Synthesis

    Directory of Open Access Journals (Sweden)

    Rezvan Rezaee Nasab

    2014-07-01

    Full Text Available Tungstate sulfuric acid (TSA has been prepared and used as a recyclable catalyst for the Biginelli syn-thesis of some biologically active quinazolinones/thiones under solvent-free conditions. This method has advantages such as the avoidance of organic solvents, high yield of pure products, short reaction times, and operational simplicity.  © 2014 BCREC UNDIP. All rightsReceived: 28th April 2014; Revised: 15th May 2014; Accepted: 26th May 2014[ How to Cite: Nasab, R.R., Karami, B., Khodabakhshi, S. (2014. Selective Solvent‐free Biginelli Condensation using Tungstate Sulfuric Acid as Powerful and Reusable Catalyst. Bulletin of Chemical Reaction Engineering & Catalysis, 9 (2: 142-154. (doi:10.9767/bcrec.9.2.6794.148-154][ Permalink/DOI: http://dx.doi.org/10.9767/bcrec.9.2.6794.148-154

  4. Assessing the performance under ionising radiation of lead tungstate scintillators for EM calorimetry in the CLAS12 Forward Tagger

    Science.gov (United States)

    Fegan, S.; Auffray, E.; Battaglieri, M.; Buchanan, E.; Caiffi, B.; Celentano, A.; Colaneri, L.; D`Angelo, A.; De Vita, R.; Dormenev, V.; Fanchini, E.; Lanza, L.; Novotny, R. W.; Parodi, F.; Rizzo, A.; Sokhan, D.; Tarasov, I.; Zonta, I.

    2015-07-01

    The well-established technology of electromagnetic calorimetry using Lead Tungstate crystals has recently seen an upheaval, with the closure of one of the most experienced large-scale suppliers of such crystals, the Bogoroditsk Technical Chemical Plant (BTCP), which was instrumental in the development of mass production procedures for PWO-II, the current benchmark for this scintillator. Obtaining alternative supplies of Lead Tungstate crystals matching the demanding specifications of contemporary calorimeter devices now presents a significant challenge to detector research and development programmes. In this paper we describe a programme of assessment carried out for the selection, based upon the performance under irradiation, of Lead Tungstate crystals for use in the Forward Tagger device, part of the CLAS12 detector in Hall B at Jefferson Lab. The crystals tested were acquired from SICCAS, the Shanghai Institute of Ceramics, Chinese Academy of Sciences. The tests performed are intended to maximise the performance of the detector within the practicalities of the crystal manufacturing process. Results of light transmission, before and after gamma ray irradiation, are presented and used to calculate dk, the induced radiation absorption coefficient, at 420 nm, the peak of the Lead Tungstate emission spectrum. Results for the SICCAS crystals are compared with identical measurements carried out on Bogoroditsk samples, which were acquired for the Forward Tagger development program before the closure of the facility. Also presented are a series of tests performed to determine the feasibility of recovering radiation damage to the crystals using illumination from an LED, with such illumination available in the Forward Tagger from a light monitoring system integral to the detector.

  5. Assessing the performance under ionising radiation of lead tungstate scintillators for EM calorimetry in the CLAS12 Forward Tagger

    Energy Technology Data Exchange (ETDEWEB)

    Fegan, S., E-mail: fegan@ge.infn.it [Istituto Nazionale di Fisica Nucleare, Sezione di Genova and Dipartimento di Fisica dell' Universitá, Via Dodecaneso 33, 16146 Genova (Italy); Auffray, E. [CERN, European Organisation for Nuclear Research, Geneva (Switzerland); Battaglieri, M. [Istituto Nazionale di Fisica Nucleare, Sezione di Genova and Dipartimento di Fisica dell' Universitá, Via Dodecaneso 33, 16146 Genova (Italy); Buchanan, E. [University of Glasgow, Glasgow G12 8QQ (United Kingdom); Caiffi, B.; Celentano, A. [Istituto Nazionale di Fisica Nucleare, Sezione di Genova and Dipartimento di Fisica dell' Universitá, Via Dodecaneso 33, 16146 Genova (Italy); Colaneri, L.; D' Angelo, A. [Istituto Nazionale di Fisica Nucleare, Sezione Roma2 Tor Vergata and Università degli studi di Roma Tor Vergata, Via Scientifica 1, 00133 Roma (Italy); De Vita, R. [Istituto Nazionale di Fisica Nucleare, Sezione di Genova and Dipartimento di Fisica dell' Universitá, Via Dodecaneso 33, 16146 Genova (Italy); Dormenev, V. [II. Physikalisches Institut, Universität Gießen, 35392 Gießen (Germany); Fanchini, E. [Istituto Nazionale di Fisica Nucleare, Sezione di Genova and Dipartimento di Fisica dell' Universitá, Via Dodecaneso 33, 16146 Genova (Italy); Lanza, L. [Istituto Nazionale di Fisica Nucleare, Sezione Roma2 Tor Vergata and Università degli studi di Roma Tor Vergata, Via Scientifica 1, 00133 Roma (Italy); Novotny, R.W. [II. Physikalisches Institut, Universität Gießen, 35392 Gießen (Germany); and others

    2015-07-21

    The well-established technology of electromagnetic calorimetry using Lead Tungstate crystals has recently seen an upheaval, with the closure of one of the most experienced large-scale suppliers of such crystals, the Bogoroditsk Technical Chemical Plant (BTCP), which was instrumental in the development of mass production procedures for PWO-II, the current benchmark for this scintillator. Obtaining alternative supplies of Lead Tungstate crystals matching the demanding specifications of contemporary calorimeter devices now presents a significant challenge to detector research and development programmes. In this paper we describe a programme of assessment carried out for the selection, based upon the performance under irradiation, of Lead Tungstate crystals for use in the Forward Tagger device, part of the CLAS12 detector in Hall B at Jefferson Lab. The crystals tested were acquired from SICCAS, the Shanghai Institute of Ceramics, Chinese Academy of Sciences. The tests performed are intended to maximise the performance of the detector within the practicalities of the crystal manufacturing process. Results of light transmission, before and after gamma ray irradiation, are presented and used to calculate dk, the induced radiation absorption coefficient, at 420 nm, the peak of the Lead Tungstate emission spectrum. Results for the SICCAS crystals are compared with identical measurements carried out on Bogoroditsk samples, which were acquired for the Forward Tagger development program before the closure of the facility. Also presented are a series of tests performed to determine the feasibility of recovering radiation damage to the crystals using illumination from an LED, with such illumination available in the Forward Tagger from a light monitoring system integral to the detector.

  6. Regularities of the chlorination process of phosphates and tungstates of some actinide and fission elements in chloride melts

    International Nuclear Information System (INIS)

    Kryukova, A.I.; Chernikov, A.A.; Skiba, O.V.; Kazantsev, G.N.

    1988-01-01

    Results of kinetic studies of chlorination process of crystal phosphates and tungstates of uranium, cerium, zirconium, plutonium by vapours of carbon tetrachloride in the melts of alkali element chlorides at of 973-1073 K have been analyzed. Mathematical models for the process description are suggested. Analysis of adequate models of regression type permitted to solve the problem of statistical evaluation of affecting factors and to predict within factor space studied the conditions for the optimal process course

  7. The roles of phosphate and tungstate species in surface acidities of TiO2-ZrO2 binary oxides - A comparison study

    Science.gov (United States)

    Chaudhary, Manchal; Shen, Po-fan; Chang, Sue-min

    2018-05-01

    Porous tungstated and phosphated TiO2-ZrO2 (TZ) binary oxides with high and strong acidity were successfully prepared by means of sol-gel or impregnation approaches. In addition, the influences of the two types of modifiers on the microstructures and acidity were systematically examined, compared, and clarified. The TZ oxide derived from a surfactant-templating method exhibited a high surface area of 195 m2/g with a pore size of 6.3 nm. Moreover, it had a high acidity of 859 μmol/g with a density of 4.4 μmol/nm2 because of defective surface. Phosphation significantly increased the acidity to 1547 μmol/g and showed the highest acid density of 6.7 μmol/nm2 at a surface P density of 22.7P/nm2. On the other hand, tungstated compounds just showed the highest acidity of 972 μmol/g and the highest acid density of 4.8 μmol/nm2 at 4.7 W/nm2. Compared to tungstate species, phosphate anions are more capable of promoting the acidity because they are able to distort the host network and inhibit elemental rearrangement. While Lewis acidity prevailed in the tungstated compounds, Brønsted acidity was dominant in the phosphated oxides. The Wdbnd O and Psbnd OH groups were responsible for strong acidity in the modified compounds. Phosphated compounds formed strong Brønsted acid sites on the Psbnd OH groups with a particular strength, and tungstation produced Lewis acid sites with a continuous strength on the metal ions adjacent to the tungstate moieties. Cyclic NH3 adsorption-desorption processes revealed that the active sites for NH3 adsorption were stable in both the tungstate and phosphate modified compounds, revealing that these solid acids are promising as the adsorbents for removal of base gases.

  8. Tungsten Trioxide/Zinc Tungstate Bilayers: Electrochromic Behaviors, Energy Storage and Electron Transfer

    International Nuclear Information System (INIS)

    Wei, Huige; Ding, Daowei; Yan, Xingru; Guo, Jiang; Shao, Lu; Chen, Haoran; Sun, Luyi; Colorado, Henry A.; Wei, Suying; Guo, Zhanhu

    2014-01-01

    Highlights: • Tungsten oxide and zinc tungstate bilayers have been prepared via a facile sol-gel method for integrated applications of electrochromic behaviors and energy storage;. • Electron transfer behaviors between the semiconductor bilayer films have been found dependent on the bilayer assembly sequence;. • Methylene blue (MB) has been employed for the first time as an indicator to study the electron transfer phenomenon in the bilayer films. - Abstract: Pair-sequentially spin-coated tungsten trioxide (WO 3 ) and zinc tungstate (ZnWO 4 ) bilayer films onto indium tin oxide (ITO) coated glass slides have been prepared via sol-gel methods followed by annealing. The bilayers (ZnWO 4 /WO 3 denoting the bilayer film with the inner layer of ZnWO 4 and the outer layer of WO 3 on the ITO while WO 3 /ZnWO 4 standing for the bilayer film with the inner layer of WO 3 and the outer layer of ZnWO 4 on the ITO) exhibit integrated functions of electrochromic and energy storage behaviors as indicated by the in situ spectroelectrochemistry and cyclic voltammetry (CV) results. Accordingly, blue color was observed for the bilayer films at -1 V in 0.5 M H 2 SO 4 solution. An areal capacitance of 140 and 230 μF/cm 2 was obtained for the ZnWO 4 /WO 3 , and WO 3 /ZnWO 4 film, respectively, at a scan rate of 0.05 V/s in the CV measurements. The CV results also unveiled the electron transfer behavior between the semiconductor films in the oxidation process, suggesting a sequence-dependent electrochemical response in the bilayer films. Meanwhile, methylene blue (MB) was used as an indicator to study the electron transfer phenomenon during the reduction process at negative potentials of -0.4 and -0.8 V, in 0.5 M Na 2 SO 4 . The results indicated that the electrons transfer across the bilayers was enhanced at more negative potentials

  9. Haemoglobin adducts of acrylonitrile and ethylene oxide in acrylonitrile workers, dependent on polymorphisms of the glutathione transferases GSTT1 and GSTM1.

    Science.gov (United States)

    Thier, R; Lewalter, J; Kempkes, M; Selinski, S; Brüning, T; Bolt, H M

    1999-01-01

    Fifty-nine persons with industrial handling of low levels of acrylonitrile (AN) were studied. As part of a medical surveillance programme an extended haemoglobin adduct monitoring [N-(cyanoethyl)valine, CEV; N-(methyl)valine. MV: N-(hydroxyethyl)valine, HEV] was performed. Moreover, the genetic states of the polymorphic glutathione transferases GSTM1 and GSTT1 were assayed by polymerase chain reaction (PCR). Repetitive analyses of CEV and MV in subsequent years resulted in comparable values (means, 59.8 and 70.3 microg CEV/1 blood; 6.7 and 6.7 microg MV/1 blood). Hence, the industrial AN exposures were well below current official standards. Monitoring the haemoglobin adduct CEV appears as a suitable means of biomonitoring and medical surveillance under such exposure conditions. There was also no apparent correlation between the CEV and HEV or CEV and MV adduct levels. The MV and HEV values observed represented background levels, which apparently are not related to any occupational chemical exposure. There was no consistent effect of the genetic GSTM1 or GSTT1 state on CEV adduct levels induced by acrylonitrile exposure. Therefore, neither GSTM1 nor GSTT1 appears as a major AN metabolizing isoenzyme in humans. The low and physiological background levels of MV were also not influenced by the genetic GSTM1 state, but the MV adduct levels tended to be higher in GSTT1- individuals compared to GSTT1 + persons. With respect to the background levels of HEV adducts observed, there was no major influence of the GSTM1 state, but GST- individuals displayed adduct levels that were about 1/3 higher than those of GSTT1 + individuals. The coincidence with known differences in rates of background sister chromatid exchange between GSTT1- and GSTT1 + persons suggests that the lower ethylene oxide (EO) detoxification rate in GSTT1- persons, indicated by elevated blood protein hydroxyethyl adduct levels, leads to an increased genotoxic effect of the physiological EO background.

  10. Control of insects with fumigants at low temperatures: toxicity of mixtures of methyl bromide and acrylonitrile to three species of insects

    Energy Technology Data Exchange (ETDEWEB)

    Bond, E.J.; Buckland, C.T.

    1976-12-15

    Acrylonitrile can be mixed with methyl bromide to increase toxicity so that the quantity of methyl bromide required for control of Sitophilus granarius (L.), Tenebrio molitor L., and Tribolium confusum Jacquelin duval is reduced by one half. Mixtures of methyl bromide and acrylonitrile are considerably more effective at low temperatures than methyl bromide alone.

  11. Synthesis of alkaline-earth metal tungstates in melts of [NaNO3-M(NO3)2]eut-Na2WO4 (M=Ca, Sr, Ba) system

    International Nuclear Information System (INIS)

    Shurdumov, G.K.; Shurdumova, Z.V.; Cherkesov, Z.A.; Karmokov, A.M.

    2006-01-01

    Synthesis of alkaline earth metal tungstates in melts of eutectics of NaNO 3 -M(NO 3 ) 2 ] (M=Ca, Sr, Ba) is done. Synthesis is based in exchange reaction of calcium, strontium, and barium nitrates with sodium tungstate [ru

  12. Use of rice straw and radiation-modified maize starch/acrylonitrile in the treatment of wastewater

    International Nuclear Information System (INIS)

    Abdel-Aal, S.E.; Gad, Y.H.; Dessouki, A.M.

    2006-01-01

    Graft copolymerization of acrylonitrile onto maize starch by a simultaneous irradiation technique using gamma-rays as the initiator was studied with regard to the various parameters of importance: the monomer-to-maize starch ratio and total dose (kGy). The water absorption of the modified maize starch was measured. The starch modified by acrylonitrile gives low water absorbance. Conversion of the copolymer to the amidoxime form gives high swelling. The gel (%) and the grafting efficiency were measured. An investigation was carried out to study the adsorption of basic violet 7, basic blue 3, direct yellow 50 and acid red 37 from aqueous solutions by the water-insoluble modified starch containing amidoxime groups and rice straw. The effects of initial pH of the solution, pollutant concentration and treatment time on the adsorption were studied and it was found that the maximum adsorption was at 1:2 (starch/acrylonitrile) at irradiation dose 30 kGy

  13. Optimization of process parameters for acrylonitrile removal by a low-cost adsorbent using Box-Behnken design

    International Nuclear Information System (INIS)

    Kumar, Arvind; Prasad, B.; Mishra, I.M.

    2008-01-01

    In the present work, acrylonitrile removal from wastewater was investigated using an agri-based adsorbent-sugarcane bagasse fly ash (BFA). The effect of such parameters as adsorbent dose (w), temperature (T) and time of contact (t) on the sorption of acrylonitrile by BFA was investigated using response surface methodology (RSM) based on Box-Behnken surface statistical design at an initial acrylonitrile concentration, C 0 = 100 mg/l as a fixed input parameter. The results of RSM indicate that the proposed models predict the responses adequately within the limits of input parameters being used. The isotherm shows a two-step adsorption, well represented by a two-step Langmuir isotherm equation. Thermodynamic parameters indicate the sorption process to be spontaneous and exothermic

  14. Elevated gamma-rays shielding property in lead-free bismuth tungstate by nanofabricating structures

    Science.gov (United States)

    Liu, Jun-Hua; Zhang, Quan-Ping; Sun, Nan; Zhao, Yang; Shi, Rui; Zhou, Yuan-Lin; Zheng, Jian

    2018-01-01

    Radiation shielding materials have attracted much attention across academia and industry because of the increasing of nuclear activities. To achieve the materials with low toxicity but good protective capability is one of the most significant goals for personal protective articles. Here, bismuth tungstate nanostructures are controllably fabricated by a versatile hydrothermal treatment under various temperatures. The crystals structure and morphology of products are detailedly characterized with X-ray diffraction, electron microscope and specific surface area. It is noteworthy that desired Bi2WO6 nanosheets treated with 190 °C show the higher specific surface area (19.5 m2g-1) than that of the other two products. Importantly, it has a close attenuating property to lead based counterpart for low energy gamma-rays. Due to the less toxicity, Bi2WO6 nanosheets are more suitable than lead based materials to fabricate personal protective articles for shielding low energy radiations and have great application prospect as well as market potential.

  15. Sonochemical synthesis of terbium tungstate for developing high power supercapacitors with enhanced energy densities.

    Science.gov (United States)

    Sobhani-Nasab, Ali; Rahimi-Nasrabadi, Mehdi; Naderi, Hamid Reza; Pourmohamadian, Vafa; Ahmadi, Farhad; Ganjali, Mohammad Reza; Ehrlich, Hermann

    2018-07-01

    Sonochemically prepared nanoparticles of terbium tungstate (TWNPs) were evaluated through scanning electron microscopy (SEM), thermogravimetric analysis (TGA), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR), UV-Vis spectroscopy, and the optimal products were further characterized in terms of their electrochemical properties using conventional and continuous cyclic voltammetry (CV, and CCV), galvanostatic charge/discharge technique, and electrochemical impedance spectroscopy (EIS). The CV studies indicated the TWNPs to have specific capacitance (SC) values of 336 and 205 F g -1 at 1 and 200 mV s -1 , and galvanostatic charge-discharge tests revealed the SC of the TWNP-based electrodes to be 300 F g -1 at 1 Ag -1 . Also continuous cyclic voltammetry evaluations proved the sample as having a capacitance retention value of 95.3% after applying 4000 potential cycles. In the light of the results TWNPs were concluded as favorable electrode materials for use in hybrid vehicle systems. Copyright © 2018 Elsevier B.V. All rights reserved.

  16. Vapour phase dehydration of glycerol to acrolein over tungstated zirconia catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Rao Ginjupalli, Srinivasa; Mugawar, Sowmya; Rajan, Pethan N.; Kumar Balla, Putra; Chary Komandur, V.R., E-mail: kvrchary@iict.res.in

    2014-08-01

    Tetragonal (TZ) and monoclinic (MZ) polymorphs of zirconia supports were synthesised by sol–gel method followed by variation of the calcination temperature. Tungstated (10 wt% WO{sub 3}) supported on the zirconia polymorphs were prepared by impregnation method by using ammonium metatungstate precursor. The physico-chemical properties of the calcined catalysts were characterised by X-ray diffraction, UV–vis diffused reflectance spectroscopy, X-ray photoelectron spectroscopy (XPS), surface area and pore size distribution measurements to gain insight into the effect of morphology of the catalyst textural properties, and structure. The surface acidic properties have been determined by NH{sub 3} TPD method and also with FT-IR spectra of pyridine adsorption. Vapour phase dehydration of glycerol to acrolein was employed to investigate the catalytic functionalities. Glycerol conversion and acrolein selectivity was mainly dependent on the fraction of moderate acid sites with majority of them are due to Brønsted acidic sites. Monoclinic zirconia based catalysts have shown the highest activity and acrolein selectivity compared to the corresponding tetragonal zirconia catalysts.

  17. redox reactions of uranium in the presence of potassium 2-phospho-17-tungstate

    International Nuclear Information System (INIS)

    Maslov, L.P.; Rykov, A.G.; Sirotinkina, L.V.

    1986-01-01

    The redox reactions of uranium in the presence of potassium 2-phospho-17-tungstate (17W2P) - K 10 P 2 W 17 O 61 - were studied by the methods of spectrophotometry and potentiometry. It was established that in the presence of 17W2P the UO /SUP 2/2/ + ion is reduced by iron(II) to uranium(IV) as a result of the binding of U(IV) into a strong complex with composition (U(p 2 W 17 O 61 ) 2 ) 16- . The peculiarities of the coordination of uranium(IV) by voluminous 17W2P ligands are the cause of the different nature of its interaction with various types of oxidizing agents. It was established that under the action of oxidizing agents (K 2 Cr 2 O 7 , KMnO 4 ), the reduced form of which is a complex with 17W2P, there is a conversion of the complex of uranium(IV) to the corresponding complex of uranium(V), evidently with conservation of a structure analogous to that for uranium(IV). It was also shown that uranium(IV) in complex with 17W2P is practically not oxidized in the cold by persulfate ions which react according to a radical mechanism, whereas weaker oxidizing agents, for example, H 2 O 2 , oxidize it to the UO /SUP 2/2/ + ion. Hypotheses are advanced on the possible mechanisms of the occurrence of the corresponding reactions

  18. Compton profiles and Mulliken’s populations of cobalt, nickel and copper tungstates: Experiment and theory

    Energy Technology Data Exchange (ETDEWEB)

    Meena, B.S. [Department of Physics, M.L. Sukhadia University, Udaipur 313001, Rajasthan (India); Heda, N.L. [Department of Pure and Applied Physics, University of Kota, Kota 324010, Rajasthan (India); Kumar, Kishor; Bhatt, Samir; Mund, H.S. [Department of Physics, M.L. Sukhadia University, Udaipur 313001, Rajasthan (India); Ahuja, B.L., E-mail: blahuja@yahoo.com [Department of Physics, M.L. Sukhadia University, Udaipur 313001, Rajasthan (India)

    2016-03-01

    We present the first ever studies on Compton profiles of AWO{sub 4} (A=Co, Ni and Cu) using 661.65 keV γ-rays emitted by {sup 137}Cs source. The experimental momentum densities have been employed to validate exchange and correlation potentials within linear combination of atomic orbitals (LCAO) method. Density functional theory (DFT) with local density approximation and generalized gradient approximation and also the hybridization of Hartree-Fock and DFT (B3LYP and PBE0) have been considered under LCAO scheme. The LCAO-B3LYP scheme is found to be in better agreement with the experimental data than other approximations considered in this work, suggesting applicability of B3LYP approach in predicting the electronic properties of these tungstates. The Mulliken’s population (MP) data show charge transfer from Co/Ni/Cu and W to O atoms. The experimental profiles when normalized to same area show almost similar localization of 3d electrons (in real space) of Ni and Cu which is lower than that of Co in their AWO{sub 4} environment.

  19. Ion-exchange properties of microporous tungstates: novel adsorbents for nuclear waste management applications

    International Nuclear Information System (INIS)

    Griffith, C.S.; Luca, V.; Eddowes, R.C.; Keegan, E.A.; Scales, N.

    2003-01-01

    A hydrothermally prepared tungsten oxide-based phase, ATS-1 (ANSTO Tungstate Sorbent), of nominal composition, Na 0.3 Mo 0.1 W 0.9O3 .χH 2 O, has been shown to display promising selectivity for both Cs + and Sr 2+ cations from acidic simulant, indicative of the Intermediate Level Liquid Waste (ILLW) produced from 99 Mo radioisotope production at the ANSTO site. The development of an inorganic ion-exchanger that displays such selectivity for both Cs + and Sr 2+ in acidic solutions has previously eluded researchers in the field of inorganic ion-exchangers. The ATS-1 adsorbent also displays exquisite selectivity for lead (and polonium) in low to high acidity solutions, and as such is being further investigated as a method to reduce the radiological hazard from 210 Pb and 210 Po during the processing of uranium ore bodies. The adsorption of Cs + , Sr 2+ and Pb 2+ cations by ATS-1 has been extensively investigated with respect to the kinetics of adsorption, capacity and the effect of competing cations viz. Na + , K + . The ATS-1 adsorbent has also been successfully granulated with an inert, organic matrix, which has consequently allowed the study of cation adsorption using more application-based, column separations. The results of these investigations suggest that these materials have potential application in several nuclear waste management issues in Australia at the present

  20. Efficient photo-catalytic degradation of malachite green using nickel tungstate material as photo-catalyst.

    Science.gov (United States)

    Helaïli, N; Boudjamaa, A; Kebir, M; Bachari, K

    2017-03-01

    The present study focused on the evaluation of photo-catalytic and photo-electrochemical properties of the photo-catalyst based on nickel tungstate material prepared by a nitrate method through the degradation of malachite green (MG) dye's. The effect of catalyst loading and dye concentration was examined. Physico-chemical, optical, electrical, electrochemical, and photo-electrochemical properties of the prepared material were analyzed by X-ray diffraction (XRD), fourier transform-infrared spectroscopy (FTIR), BET analysis, optical reflectance diffuse (DR), scanning electron microscopy (SEM/EDX), electrical conductivity, cyclic voltammetry (CV), current intensity, mott-shottky, and nyquist. XRD revealed the formation of monoclinic structure with a small particle size. BET surface area of the sample was around 10 m 2 /g. The results show that the degradation of MG was more than 80%, achieved after 3 h of irradiation at pH 4.6 and with a catalyst loading of 75 mg. Also, it was found that the dye photo-degradation obeyed the pseudo-first order kinetic via Langmuir Hinshelwood model.

  1. Investigation on the photophysical properties of tungsten trioxide and tungstate based nanocomposites

    Science.gov (United States)

    Palanisamy, G.; Pazhanivel, T.

    2018-04-01

    Tungsten trioxide (WO3), Metal tungstates (SrWO4, Cr2WO6), WO3/SrWO4 and WO3/Cr2WO6 nanocomposites were successfully prepared by microwave irradiation method at relatively low temperature (500 °C). The synthesized samples were subjected to different investigation techniques, to know the materials physical and chemical properties. The structural and phase change formation of nanoparticles were investigated through XRD analysis. It shows that, the nanoparticles have highly crystalline nature. The shape and composition of the prepared nanoparticles were investigated through SEM and EDAX analysis. The optical properties of the synthesized samples were verified by Ultraviolet-diffuse reflectance spectroscopy and photoluminescence spectrometer. The emission intensity maximum of WO3 nanoparticle was red shifted when compared to composites. It may be due to the effect of delocalized electrons in the parent material. Simultaneously, the emission intensity was decreased because of trap states occurred on the surface of the composite nanoparticles. The photoluminescence spectra of the synthesized samples exhibit different emission (violet and blue) behavior. Hence, it may be useful for light emitting diode (LED) applications.

  2. Transport and dielectric studies on silver based molybdo-tungstate quaternary superionic conducting glasses

    International Nuclear Information System (INIS)

    Prasad, P.S.S.; Radhakrishna, S.

    1988-01-01

    The molybdo-tungstate (MoO 3 -WO 3 ) combination of glass formers with silver oxide (Ag 2 O) as glass modifier and silver iodide (AgI) as ionic conductor were prepared to study the transport and dielectric properties of 60% AgI-40% (x Ag 2 O-y(WO 3 -MoO 3 )) for x/y=0.33 to 3.0 and establish the feasibility of using these glasses as electrolytes in the fabrication and characterisation of solid state batteries and potential memory devices. The details of the preparation of glasses and methods of measurement of their capacitance, dielectric loss factor and ac conductivity in the frequency range 100 Hz - 100 kHz from 30-120 C have been reported. The electronic contribution to the total conductivity, the ionic and electronic transport numbers were determined using Wagners dc polarisation technique. The observed high ionic and low electronic conductivities were attributed to the formation of ionic clusters in the glass and the effect of mixing two glass formers. The observed total ionic conductivity and its temperature dependence was explained using Arrhenius relation σ=σ 0 /T exp(-E/RT) and the measured dielectric constant and dielectric loss were explained on the basis of Jonschers theory. The frequency dependence of dielectric constant obeys the theory based on the polarisation of ions. 25 refs.; 8 figs

  3. Some peculiarities of zirconium tungstate synthesis by thermal decomposition of hydrothermal precursors

    International Nuclear Information System (INIS)

    Gubanov, Alexander I.; Dedova, Elena S.; Plyusnin, Pavel E.; Filatov, Eugeny Y.; Kardash, Tatyana Y.; Korenev, Sergey V.; Kulkov, Sergey N.

    2014-01-01

    Highlights: • Synthesis of ZrW 2 O 8 using hydrothermal method. • On hydrothermal synthesis optimal conc. of HCl in the reaction mixture is 2.3 M. • Thermal decomposition of ZrW 2 O 7 ((OH) 1.5 ,Cl 0.5 )·2H 2 O begins are 200 °S. • Amorphous intermediate crystallizes into cubic single-phase ZrW 2 O 8 above 550 °S. • ZrW 2 O 8 destructed at temperatures above 700 °S. - Abstract: This article discusses some peculiarities of the synthesis of ZrW 2 O 8 (1) using thermal decomposition of the precursor ZrW 2 O 7 ((OH) 1.5 ,Cl 0.5 )·2H 2 O (2) prepared by hydrothermal method. On hydrothermal synthesis of 2 the optimal concentration of hydrochloric acid in the reaction mixture is about 2.3 M. TG approach to determine the chemical composition of the precursor was suggested. It has been found that the precursor for the synthesis of zirconium tungstate has chemical formula 2. Thermal decomposition of the precursor 2 begins at 200 °S and affords an amorphous intermediate, which crystallizes as a cubic phase 1 above 550 °S with an exoeffect. The temperature of the beginning of the transition from amorphous to the crystalline state is 350 ± 25 °S

  4. Vapour phase dehydration of glycerol to acrolein over tungstated zirconia catalysts

    Science.gov (United States)

    Rao Ginjupalli, Srinivasa; Mugawar, Sowmya; Rajan N., Pethan; Kumar Balla, Putra; Chary Komandur, V. R.

    2014-08-01

    Tetragonal (TZ) and monoclinic (MZ) polymorphs of zirconia supports were synthesised by sol-gel method followed by variation of the calcination temperature. Tungstated (10 wt% WO3) supported on the zirconia polymorphs were prepared by impregnation method by using ammonium metatungstate precursor. The physico-chemical properties of the calcined catalysts were characterised by X-ray diffraction, UV-vis diffused reflectance spectroscopy, X-ray photoelectron spectroscopy (XPS), surface area and pore size distribution measurements to gain insight into the effect of morphology of the catalyst textural properties, and structure. The surface acidic properties have been determined by NH3 TPD method and also with FT-IR spectra of pyridine adsorption. Vapour phase dehydration of glycerol to acrolein was employed to investigate the catalytic functionalities. Glycerol conversion and acrolein selectivity was mainly dependent on the fraction of moderate acid sites with majority of them are due to Brønsted acidic sites. Monoclinic zirconia based catalysts have shown the highest activity and acrolein selectivity compared to the corresponding tetragonal zirconia catalysts.

  5. Vapour phase dehydration of glycerol to acrolein over tungstated zirconia catalysts

    International Nuclear Information System (INIS)

    Rao Ginjupalli, Srinivasa; Mugawar, Sowmya; Rajan, Pethan N.; Kumar Balla, Putra; Chary Komandur, V.R.

    2014-01-01

    Tetragonal (TZ) and monoclinic (MZ) polymorphs of zirconia supports were synthesised by sol–gel method followed by variation of the calcination temperature. Tungstated (10 wt% WO 3 ) supported on the zirconia polymorphs were prepared by impregnation method by using ammonium metatungstate precursor. The physico-chemical properties of the calcined catalysts were characterised by X-ray diffraction, UV–vis diffused reflectance spectroscopy, X-ray photoelectron spectroscopy (XPS), surface area and pore size distribution measurements to gain insight into the effect of morphology of the catalyst textural properties, and structure. The surface acidic properties have been determined by NH 3 TPD method and also with FT-IR spectra of pyridine adsorption. Vapour phase dehydration of glycerol to acrolein was employed to investigate the catalytic functionalities. Glycerol conversion and acrolein selectivity was mainly dependent on the fraction of moderate acid sites with majority of them are due to Brønsted acidic sites. Monoclinic zirconia based catalysts have shown the highest activity and acrolein selectivity compared to the corresponding tetragonal zirconia catalysts.

  6. Monitoring and Correcting for Response Changes in the CMS Lead-tungstate Electromagnetic Calorimeter

    International Nuclear Information System (INIS)

    Ferri, Federico

    2012-01-01

    The CMS Electromagnetic Calorimeter (ECAL) comprises 75848 lead-tungstate scintillating crystals. Changes in the ECAL response, due to crystal radiation damage or changes in photo-detector output, are monitored in real time with a sophisticated system of lasers to allow corrections to the energy measurements to be calculated and used. The excellent intrinsic resolution of the CMS ECAL requires the monitoring system itself to be calibrated to a high precision and its stability to be controlled and understood. The components of the CMS ECAL monitoring system, and how it has evolved to include modern solid-state lasers, are described. Several physics channels are exploited to normalise the ECAL response to the changes measured by the monitoring system. These include low energy diphoton resonances, electrons from W and Z decays (using shower energy versus track momentum measurements), and the azimuthal symmetry of low energy deposits in minimum bias events. This paper describes how the monitoring system is operated, how the corrections are obtained, and the resulting ECAL performance.

  7. An investigation on the preparation of nanocrystalline hydrous zirconia from zirconium tungstate

    Science.gov (United States)

    Antunes, M.; Perottoni, C. A.; Gouvêa, D.; Machado, G.; Zorzi, J. E.

    2018-02-01

    Hydrous nanocrystalline zirconia was prepared from an unusual precursor—the bimetallic oxide zirconium tungstate (ZrW2O8)—in alkaline medium. Different experimental conditions (NaOH concentration, time and temperature) were used to investigate the effects on crystallographic, morphological, chemical and thermal characteristics of the products. The resulting materials are composed of particles with a crystal structure similar to that of cubic ZrO2 (or a mixture of tetragonal and cubic phases, depending on the synthesis conditions), with particle size around 5 nm and crystallites around 3 nm in diameter. These particles form high surface area agglomerates, exhibiting mesoporosity and capacity for adsorption of water and carbon dioxide. The synthesis mechanism appears to be constituted, first, by a chemical substitution reaction between the WO4 tetrahedra and hydroxyl ions, with subsequent solubilization of the structure. Indeed, excess hydroxyls in the medium form colloidal zirconium ions which polymerize/condense, generating crystalline nuclei in a process facilitated by heterogeneous nucleation and supersaturation. The presence of residual tungsten in all samples appears to be a key element for stabilizing the size and crystalline structure of the materials produced.

  8. Zirconium tungstate/epoxy nanocomposites: effect of nanoparticle morphology and negative thermal expansivity.

    Science.gov (United States)

    Wu, Hongchao; Rogalski, Mark; Kessler, Michael R

    2013-10-09

    The ability to tailor the coefficient of thermal expansion (CTE) of a polymer is essential for mitigating thermal residual stress and reducing microcracks caused by CTE mismatch of different components in electronic applications. This work studies the effect of morphology and thermal expansivity of zirconium tungstate nanoparticles on the rheological, thermo-mechanical, dynamic-mechanical, and dielectric properties of ZrW2O8/epoxy nanocomposites. Three types of ZrW2O8 nanoparticles were synthesized under different hydrothermal conditions and their distinct properties were characterized, including morphology, particle size, aspect ratio, surface area, and CTE. Nanoparticles with a smaller particle size and larger surface area led to a more significant reduction in gel-time and glass transition temperature of the epoxy nanocomposites, while a higher initial viscosity and significant shear thinning behavior was found in prepolymer suspensions containing ZrW2O8 with larger particle sizes and aspect ratios. The thermo- and dynamic-mechanical properties of epoxy-based nanocomposites improved with increasing loadings of the three types of ZrW2O8 nanoparticles. In addition, the introduced ZrW2O8 nanoparticles did not negatively affect the dielectric constant or the breakdown strength of the epoxy resin, suggesting potential applications of ZrW2O8/epoxy nanocomposites in the microelectronic insulation industry.

  9. Radiation-induced in-source polymerization of acrylonitrile in urea canal complex

    International Nuclear Information System (INIS)

    Yoshii, Fumio; Abe, Toshihiko; Kobayashi, Yasushi.

    1975-01-01

    Effect of reaction conditions on the radiation-induced in-source polymerization of acrylonitrile in urea canal complex and the properties of obtained polyacrylonitriles were investigated. The results were discussed in comparison with previously reported of the post-polymerization experiments. 1) Rate of polymerization and viscosity (eta sub(sp)/C) were the highest when the molar ratio of acrylonitrile to urea in canal complex was unity. Similar results were also obtained in the post-polymerization. However, eta sub(sp)/C exhibited different behavior on polymerization time in comparison with post-polymerization. 2) The initial rate (Rsub(p)) of polymerization is proportional to the dose rate (I) at low dose rate, but at high dose rates (above 2x10 5 r/hr) makes Rsub(p) proportional to Isup(0.5). 3) Molecular weight distribution become broader with increasing polymerization time and is broad as compared with those obtained by the post-polymerization. G-value of initiation of polymerization decreased with increasing polymerization time. These value was larger than the that obtained in the post-polymerization. 4) The stereoregularity of the polyacrylonitriles was independent of the molar ratio of acrylonitrile to urea in the canal complex and conversion. 5) The appearance of the polyacrylonitriles observed by the scanning electron microscope changed from curled string to extended one as the polymerization proceed. 6) Infrared spectrum revealed the ketenimine and cyclization structure in the polyacrylonitriles obtained below -100 0 C. The content of these abnormal structures increased with increasing conversion. (auth.)

  10. Ion exchange membranes based on vinylphosphonic acid-co-acrylonitrile copolymers for fuel cells

    Czech Academy of Sciences Publication Activity Database

    Žitka, Jan; Bleha, Miroslav; Schauer, Jan; Galajdová, Barbora; Paidar, M.; Hnát, J.; Bouzek, K.

    2015-01-01

    Roč. 56, č. 12 (2015), s. 3167-3173 ISSN 1944-3994. [International Conference on Membrane and Electromembrane Processes - MELPRO 2014. Prague, 18.05.2014-21.05.2014] R&D Projects: GA ČR(CZ) GPP106/12/P643 EU Projects: European Commission(XE) 608931 - MAT4BAT Institutional support: RVO:61389013 Keywords : vinylphosphonic acid * poly(vinylphosphonic acid-co-acrylonitrile) * ionic conductivity Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.272, year: 2015

  11. On the some reactions of mixed ethers of phosphorus acid with acrylonitrile and methyl iodide

    International Nuclear Information System (INIS)

    Gusev, Yu.K.; Chistokletov, V.N.; Petrov, A.A.

    1977-01-01

    The bimolecular mechanism has been confirmed of the redgrouping stage of Arbuzov's classical reactions for phosphites containing primary and secondary radicals in reactions of acrylonitrile and methyl iodide with some mixed ethers of phosphoric acid. It is suggested that dealcylation of the intermediate products formed on interaction of olefins activated by electron-acceptor groups with phosphites containing primary radicals occurs according to the Ssub(N)2-mechanism, secondary radicals, according to the mixed Ssub(N)2 and Ssub(N)1-mechanism,and radicals capable of forming stable carbonium ions, according to the Ssub(N)1-mechanism

  12. Detection of hydrogen dissolved in acrylonitrile butadiene rubber by 1H nuclear magnetic resonance

    Science.gov (United States)

    Nishimura, Shin; Fujiwara, Hirotada

    2012-01-01

    Rubber materials, which are used for hydrogen gas seal, can dissolve hydrogen during exposure in high-pressure hydrogen gas. Dissolved hydrogen molecules were detected by solid state 1H NMR of the unfilled vulcanized acrylonitrile butadiene rubber. Two signals were observed at 4.5 ppm and 4.8 ppm, which were assignable to dissolved hydrogen, in the 1H NMR spectrum of NBR after being exposed 100 MPa hydrogen gas for 24 h at room temperature. These signals were shifted from that of gaseous hydrogen molecules. Assignment of the signals was confirmed by quantitative estimation of dissolved hydrogen and peak area of the signals.

  13. Grafting of polyethylene films with acrylic acid and acrylonitril using gamma radiation

    International Nuclear Information System (INIS)

    Ajji, Z.; Al-Nesr, E.

    2003-12-01

    Acrylic acid (AAc) and acrylonitrile (AN) and their binary mixtures were graft copolymerized onto low density polyethylene (LDPE) films using gamma irradiation. The effects of different parameters on the graft yield were studies such as monomer concentration, inhibitor concentration, and irradiation dose. The obtained grafted films were characterized using FTIR spectroscopy, thermal gravimetry, and differential scanning calorimetry. Water uptake and the ion uptake were also evaluated, and the ability of grafted films to uptake heavy ions such as Ni 2+ and Cu 2+ was discussed. (author)

  14. Study of PVC membrane grafted by Acrylic Acid, Acrylonitrile and Acrylamide using preirradiation method

    International Nuclear Information System (INIS)

    Kattan, M.; Al-Kasseri, H.

    2015-03-01

    Grafting of acrylic acid, acrylamide and acrylonitrile onto poly vinyl chloride (PVC) films using gamma radiation has been carried out by both type direct and preirradiation methods. The effect of different parameter such as monomer concentration, inhibitor concentration, reaction temperature, reaction time and irradiation dose on the grafting yield were investigated. It was found that the grafting yield depends on these parameters. The grafting yield was strongly monomer dependent and grafting method: the highest was found for AAc by the preirradiation method. The samples were characterized by tensile strength measurement, swilling and ion uptake. The highest increase in swilling was observed on samples grafted with AAc by the preirradiation method.(author)

  15. Use of Biomass as a Sustainable and Green Fuel with Alkali-Resistant DeNOx Catalysts based on Sulfated or Tungstated Zirconia

    DEFF Research Database (Denmark)

    Due-Hansen, Johannes; Fehrmann, Rasmus; Christensen, Claus H.

    poisons is the use of supports with highly acidic properties, which would interact stronger with potassium than the vanadium species. Among those, sulfated and tungstated zirconica appears very attractive, since their surface acidity can be tuned in a wide range by varying the preparation procedure, WOX......, sulfated, and tungstated zirconia were prepared and tested. The influence of potassium additives on the acidity and activity was studied and the results were compared with traditional V2O5-WO3/TiO2 catalyst. Resistance of the catalysts towards poisoning with potassium was found to depend dramatically...... on the crystallinity and surface acidity of the support used. Better resistance of the samples based on sulfated and tungstated zirconia seems to be connected with the fact that a significant part of the potassium on the surface of the catalyst preferentially interact with strong acid sites of the support thus...

  16. Proton magnetic resonance in hydrates of tungstates of 2-4th group elements of D.I. Mendeleev periodic system

    International Nuclear Information System (INIS)

    Pitsyuga, V.T.; Potarskaya, L.A.; Mokhosoev, M.V.

    1979-01-01

    By the methods of PMR and infrared-spectroscopy studied are the tungstate hydrates of Mg, Li, Cd, Al, Ge, In, Ti, Ln, Hf. The PMR spectra have been taken for air-dry and partly hydrated samples in the temperature range from 93 to 295 K. In tungstate hydrates of the 2nd and 4th groups found are the distorted moleculas of H 2 O with the intermolecular interproton distances different from 1.53 A, namely, increased up to 2.69 A and decreased to 1.38 A. Determined is the quantitative content of OH - groups and H 2 O moleculas, with different interproton distance. A formula content of the compounds studied is proposed. In tungstates of the 3d group the distorted moleculas are found only in compounds with H - /Me 2 O distortion is confirmed by the data of infrared spectr. The process of dehydration of distorted H 2 O moleculas is studied

  17. Studies in crystal structure and luminescence properties of Eu3+-doped metal tungstate phosphors for white LEDs

    International Nuclear Information System (INIS)

    Lee, Gwan-Hyoung; Kang, Shinhoo

    2011-01-01

    The correlation between the crystal structure and luminescent properties of Eu 3+ -doped metal tungstate phosphors for white LEDs was investigated. Red-emitting A 4-3x (WO 4 ) 2 :Eu x 3+ (A=Li, Na, K) and B (4-3x)/2 (WO 4 ) 2 :Eu x 3+ (B=Mg, Ca, Sr) phosphors were synthesized by solid-state reactions. The findings confirmed that these phosphors exhibited a strong absorption in the near UV to green range, due to the intra-configurational 4f-4f electron transition of Eu 3+ ions. The high doping concentration of Eu 3+ enhanced the absorption of near UV light and red emission without any detectable concentration quenching. Based on the results of a Rietveld refinement, it was attributed to the unique crystal structure. In the crystal structure of the Eu 3+ -doped metal tungstate phosphor, the critical energy transfer distance is larger than 5 A so that exchange interactions between Eu 3+ ions would occur with difficulty, even at a high doping concentration. The energy transfer between Eu 3+ ions, which causes a decrease in red emission with increasing concentration of Eu 3+ , appears to be due to electric multi-polar interactions. In addition, the Eu-O distance in the host lattice affected the shape of emission spectrum by splitting of emission peak at the 5 D 0 → 7 F 2 transition of Eu 3+ . - Highlights: → Eu 3+ -doped metal tungstate was synthesized as a red phosphor for white LEDs. → Crystal structure is tetragonal with a space group of I4 1 /c. → A strong absorption in the near UV to green range was observed. → High doping of Eu 3+ enhanced the absorption of near UV light and red emission.

  18. Luminescence investigation of R{sup 3+}-doped alkaline earth tungstates prepared by a soft chemistry method

    Energy Technology Data Exchange (ETDEWEB)

    Barbosa, Helliomar P. [Instituto de Química, Universidade de São Paulo, São Paulo, SP (Brazil); Kai, Jiang [Pontifícia Universidade Católica do Rio de Janeiro, Departamento de Química, Rio de Janeiro, RJ, Brazil (Brazil); Silva, Ivan G.N.; Rodrigues, Lucas C.V. [Instituto de Química, Universidade de São Paulo, São Paulo, SP (Brazil); Felinto, Maria C.F.C. [Centro de Química e Meio Ambiente, Instituto de Pesquisas Energéticas e Nucleares, São Paulo, SP (Brazil); Hölsä, Jorma [Instituto de Química, Universidade de São Paulo, São Paulo, SP (Brazil); Department of Chemistry, University of Turku,FI-20014 Turku (Finland); Turku University Centre for Materials and Surfaces (MatSurf), Turku (Finland); Malta, Oscar L. [Departamento de Química Fundamental, Universidade Federal de Pernambuco, Recife, PE (Brazil); Brito, Hermi F., E-mail: hefbrito@iq.usp.br [Instituto de Química, Universidade de São Paulo, São Paulo, SP (Brazil)

    2016-02-15

    Highly luminescent rare earth (R{sup 3+}) doped alkaline-earth tungstates MWO{sub 4}:R{sup 3+} (M{sup 2+}: Ca, Sr and Ba, R{sup 3+}: Eu, Tb, Gd) were prepared with a room temperature coprecipitation method. The phosphors were characterized by X-ray powder diffraction (XPD), thermal analysis (TG), infrared absorption spectroscopy (FTIR) and UV excited photoluminescence. The as-prepared MWO{sub 4}:R{sup 3+} particles belong to the tetragonal scheelite phase, and are well crystallized and are of the average size of 16–48 nm. The excitation and emission spectra of the materials were recorded at 300 and 77 K temperatures. The luminescent materials exhibit intense red (Eu{sup 3+}) and green (Tb{sup 3+}) colors under UV excitation. The excitation spectra of the Eu{sup 3+} doped materials show broad bands arising from the ligand-to-metal charge transfer transitions (O{sup 2−}→W{sup VI} and O{sup 2−}→Eu{sup 3+}) as well as narrow bands from 4f–4f intraconfigurational transitions of Eu{sup 3+}. 4f–4f emission data of the Eu{sup 3+} and Tb{sup 3+} in the MWO{sub 4} host matrices as well as the values of emission quantum efficiencies of the {sup 5}D{sub 0} level and the 4f–4f experimental intensity parameters of Eu{sup 3+} ion are presented and discussed. - Highlights: • Highly red Europium and green Terbium doped tungstate under UV excitation. • Efficient energy transfer process from tungstate to R{sup 3+} ion. • Promising candidates for a red (Eu{sup 3+}) and green (Tb{sup 3+}) emitting phosphors. • Ligand Metal charge transfer to R{sup 3+} ion. • Charge compensation with Na{sup +}.

  19. Two-dimensional spectra of electron collisions with acrylonitrile and methacrylonitrile reveal nuclear dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Regeta, K., E-mail: khrystyna.regeta@unifr.ch; Allan, M., E-mail: michael.allan@unifr.ch [Department of Chemistry, University of Fribourg, Chemin du Musée 9, CH-1700 Fribourg (Switzerland)

    2015-05-14

    Detailed experimental information on the motion of a nuclear packet on a complex (resonant) anion potential surface is obtained by measuring 2-dimensional (2D) electron energy loss spectra. The cross section is plotted as a function of incident electron energy, which determines which resonant anion state is populated, i.e., along which normal coordinate the wave packet is launched, and of the electron energy loss, which reveals into which final states each specific resonant state decays. The 2D spectra are presented for acrylonitrile and methacrylonitrile, at the incident energy range 0.095-1.0 eV, where the incoming electron is temporarily captured in the lowest π{sup ∗} orbital. The 2D spectra reveal selectivity patterns with respect to which vibrations are excited in the attachment and de-excited in the detachment. Further insight is gained by recording 1D spectra measured along horizontal, vertical, and diagonal cuts of the 2D spectrum. The methyl group in methacrylonitrile increases the resonance width 7 times. This converts the sharp resonances of acrylonitrile into boomerang structures but preserves the essence of the selectivity patterns. Selectivity of vibrational excitation by higher-lying shape resonances up to 8 eV is also reported.

  20. Novel in situ coordinated cerium salt/acrylonitrile-butadiene rubber composite

    Energy Technology Data Exchange (ETDEWEB)

    Han, Jianjun [Key Laboratory of Special Functional Aggregated Materials, Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100 (China); Lu, Haifeng, E-mail: lhf@sdu.edu.cn [Key Laboratory of Special Functional Aggregated Materials, Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100 (China); Zhang, Jie [Key Laboratory of Special Functional Aggregated Materials, Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100 (China); Feng, Shengyu, E-mail: fsy@sdu.edu.cn [Key Laboratory of Special Functional Aggregated Materials, Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100 (China)

    2012-09-14

    A novel rubber composite of acrylonitrile-butadiene rubber (NBR) filled with cerium salt particles was vulcanized via in situ coordination for the first time. The resulting materials exhibit good mechanical properties. Curing characteristics analysis, differential scanning calorimetry, X-ray photoelectron spectroscopy, tensile testing, and an equilibrium swelling method were used for the characterization of the composite. The results in this paper indicate that the composite is a kind of elastomer based on the in situ coordination crosslinking interactions between the nitrile groups (-CN) of NBR and cerium ions. The mechanical properties of vulcanized cerium salt/ NBR rubber are altered when changing the sorts of cerium salt. Moreover, these materials show good irradiation resistance because of the introduction of the cerium salt. -- Highlights: Black-Right-Pointing-Pointer Cerium salts were firstly used to vulcanize the acrylonitrile-butadiene rubber. Black-Right-Pointing-Pointer Cerium salts act as not only crosslink agents but also reinforcing fillers in the matrix. Black-Right-Pointing-Pointer These materials show good irradiation resistance and mechanical properties at same time.

  1. Novel in situ coordinated cerium salt/acrylonitrile-butadiene rubber composite

    International Nuclear Information System (INIS)

    Han, Jianjun; Lu, Haifeng; Zhang, Jie; Feng, Shengyu

    2012-01-01

    A novel rubber composite of acrylonitrile-butadiene rubber (NBR) filled with cerium salt particles was vulcanized via in situ coordination for the first time. The resulting materials exhibit good mechanical properties. Curing characteristics analysis, differential scanning calorimetry, X-ray photoelectron spectroscopy, tensile testing, and an equilibrium swelling method were used for the characterization of the composite. The results in this paper indicate that the composite is a kind of elastomer based on the in situ coordination crosslinking interactions between the nitrile groups (–CN) of NBR and cerium ions. The mechanical properties of vulcanized cerium salt/ NBR rubber are altered when changing the sorts of cerium salt. Moreover, these materials show good irradiation resistance because of the introduction of the cerium salt. -- Highlights: ► Cerium salts were firstly used to vulcanize the acrylonitrile-butadiene rubber. ► Cerium salts act as not only crosslink agents but also reinforcing fillers in the matrix. ► These materials show good irradiation resistance and mechanical properties at same time.

  2. Resonant Auger electron-photoion coincidence study of the fragmentation dynamics of an acrylonitrile molecule

    Energy Technology Data Exchange (ETDEWEB)

    Kooser, K; Ha, D T; Granroth, S; Itaelae, E; Nommiste, E; Kukk, E [Department of Physics, University of Turku, FIN-20014 Turku (Finland); Partanen, L; Aksela, H, E-mail: kunkoo@utu.f [Department of Physics, University of Oulu, Box 3000, FIN-90014 Oulu (Finland)

    2010-12-14

    Monochromatic synchrotron radiation was used to promote K-shell electrons of nitrogen and carbon from the cyano group (C {identical_to} N) of gaseous acrylonitrile (C{sub 2}H{sub 3}-CN) to the unoccupied antibonding {pi}*{sub C} {sub {identical_to} N} orbital. Photofragmentation of acrylonitrile molecules following selective resonant core excitations of carbon and nitrogen core electrons to the {pi}*{sub C} {sub {identical_to} N} orbital was investigated using the electron-energy-resolved photoelecton-photoion coincidence technique. The fragment ion mass spectra were recorded in coincidence with the resonant Auger electrons, emitted in the decay process of the core-excited states. Singly and triply deuterated samples were used for fragment identification. The results showed the initial core-hole localization to be of minor importance in determining the dissociation pattern of the molecular cation. The participator and spectator Auger transitions produce entirely different fragmentation patterns and the latter indicates that complex nuclear rearrangements take place. It is suggested that the calculated kinetic energy releases are caused by the existence of metastable states, which appear with the opening of the spectator Auger channels.

  3. Sensitive detection of acrolein and acrylonitrile with a pulsed quantum-cascade laser

    Science.gov (United States)

    Manne, J.; Lim, A.; Tulip, J.; Jäger, W.

    2012-05-01

    We report on spectroscopic measurements of acrolein and acrylonitrile at atmospheric pressure using a pulsed distributed feedback quantum-cascade laser in combination with intra- and inter-pulse techniques and compare the results. The measurements were done in the frequency region around 957 cm-1. In the inter-pulse technique, the laser is excited with short current pulses (5-10 ns), and the pulse amplitude is modulated with an external current ramp resulting in a ˜2.3 cm-1 frequency scan. In the intra-pulse technique, a linear frequency down-chirp during the pulse is used for sweeping across the absorption line. Long current pulses up to 500 ns were used for these measurements which resulted in a spectral window of ˜2.2 cm-1 during the down-chirp. These comparatively wide spectral windows facilitated the measurements of the relatively broad absorption lines (˜1 cm-1) of acrolein and acrylonitrile. The use of a room-temperature mercury-cadmium-telluride detector resulted in a completely cryogen-free spectrometer. We demonstrate ppb level detection limits within a data acquisition time of ˜10 s with these methodologies.

  4. Acrylonitrile-methyl Methacrylate Copolymer Films Containing Microencapsulated n-Octadecane

    Institute of Scientific and Technical Information of China (English)

    LI Jun; HAN Na; ZHANG Xing-xiang

    2006-01-01

    Acrylonitrile-methyl methacrylate copolymer was synthesized in aqueous solution by Redox. The copolymer was mixed with 10 - 40 wt% of microencapsulated n-octadecane (MicroPCMs) in water. Copolymer films containing MicroPCMs were cast at room temperature in N, N-Dimethylformamide solution. The copolymer of acrylonitrile-methyl methacrylate and the copolymer films containing MicroPCMs were characterized by using Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), Thermogravimetric Analyzer (TG), X-ray Diffrac tion (XRD) and Scanning Electron Microscopy (SEM), etc.The microcapsules in the films are evenly distributed in the copolymer matrix. The heat-absorbing temperatures and heat-evolving temperatures of the films are almost the same as that of the MicroPCMs, respectively, and fluctuate in a slight range. In addition, the enthalpy efficiency of MicroPCMs rises with the contents of MicroPCMs increasing.The crystallinity of the film increases with the contents of MicroPCMs increasing.

  5. Beam tests of lead tungstate crystal matrices and a silicon strip preshower detector for the CMS electromagnetic calorimeter

    CERN Document Server

    Auffray, Etiennette; Barney, D; Bassompierre, Gabriel; Benhammou, Ya; Blick, A M; Bloch, P; Bonamy, P; Bourotte, J; Buiron, L; Cavallari, F; Chipaux, Rémi; Cockerill, D J A; Dafinei, I; Davies, G; Depasse, P; Deiters, K; Diemoz, M; Dobrzynski, Ludwik; Donskov, S V; Mamouni, H E; Ercoli, C; Faure, J L; Felcini, Marta; Gautheron, F; Géléoc, M; Givernaud, Alain; Gninenko, S N; Godinovic, N; Graham, D J; Guillaud, J P; Guschin, E; Haguenauer, Maurice; Hillemanns, H; Hofer, H; Ille, B; Inyakin, A V; Jääskeläinen, S; Katchanov, V A; Kirn, T; Kloukinas, Kostas C; Korzhik, M V; Lassila-Perini, K M; Lebrun, P; Lecoq, P; Lecoeur, Gérard; Lecomte, P; Leonardi, E; Locci, E; Loos, R; Longo, E; MacKay, C K; Martin, E; Mendiburu, J P; Musienko, Yu V; Nédélec, P; Nessi-Tedaldi, F; Organtini, G; Paoletti, S; Pansart, J P; Peigneux, J P; Puljak, I; Qian, S; Reid, E; Renker, D; Rosowsky, A; Rosso, E; Rusack, R W; Rykaczewski, H; Schneegans, M; Seez, Christopher J; Semeniouk, I N; Shagin, P M; Sillou, D; Singovsky, A V; Sougonyaev, V; Soric, I; Verrecchia, P; Vialle, J P; Virdee, Tejinder S; Zhu, R Y

    1998-01-01

    Tests of lead tungstate crystal matrices carried out in high-energy electron beams in 1996, using new crystals, new APDs and an improved test set-up, confirm that an energy resolution of better than 0 .6% at 100 GeV can be obtained when the longitudinal uniformity of the struck crystal is adequate. Light loss measurements under low dose irradiation are reported. It is shown that there is no loss of energy resolution after irradiation and that the calibration change due to light loss can be tracked with a precision monitoring system. Finally, successuful tests with a preshower device, equipped wi th silicon strip detector readout, are described.

  6. Effect of tungstate on acetate and ethanol production by the electrosynthetic bacterium Sporomusa ovata

    DEFF Research Database (Denmark)

    Ammam, Fariza; Tremblay, Pier-Luc; Lizak, Dawid Mariusz

    2016-01-01

    successfully converted to their corresponding alcohols 1-propanol and 1-butanol by S. ovata during gas fermentation. Increasing tungstate concentration enhanced conversion efficiency for both propionate and butyrate. Gene expression analysis suggested that tungsten-containing aldehyde ferredoxin...... oxidoreductases (AORs) and a tungsten-containing formate dehydrogenase (FDH) were involved in the improved biosynthesis of acetate, ethanol, 1-propanol, and 1-butanol. AORs and FDH contribute to the fatty acids re-assimilation pathway and the Wood-Ljungdahl pathway, respectively. This study presented here shows...

  7. Test results from a prototype lead tungstate crystal calorimeter with vacuum phototriode readout for the CMS experiment

    Energy Technology Data Exchange (ETDEWEB)

    Apollonio, M; Barber, G; Bell, K; Britton, D; Brooke, J; Brown, R; Bourotte, J; Camanzi, B; Cockerill, D; Davies, G; Devitsin, E; Gninenko, S; Golubev, N; Goussev, Y; Grafstroem, P; Haguenauer, M; Head, R; Heath, H; Hobson, P; Inyakin, A; Katchanov, V; Kirsanov, M; Lintern, L; Lodge, A; Mcleod, E; Nash, S; Newbold, D; Ukhanov, M; Postoev, V; Patalakha, D; Presland, A; Probert, M; Seez, C; Semeniouk, I; Seliverstov, D; Smith, B; Sproston, M; Tapper, R; Tchuiko, B

    2002-05-21

    Tests of a prototype for the electromagnetic calorimeter (ECAL) of the compact muon solenoid experiment (CMS) at the large hadron collider are described. The basic unit for the endcap ECAL in CMS is a 'supercrystal' of 25 lead tungstate crystals. Results are presented from tests of the first full-sized supercrystal in electron beams and in a 3 T magnetic field. The supercrystal was exposed to electron beams with energies from 25 to 180 GeV. An energy resolution ({sigma}{sub E}/E) of (0.48{+-}0.01)% was measured at 180 GeV.

  8. Synthesis and characterization of hydroxyapatite (HAp) for binder tungstate in 188W/188Re generator system

    International Nuclear Information System (INIS)

    Eni Hartati; Yati B Yuliyati; Duyeh Setiawan

    2014-01-01

    In this study, the synthesis of hydroxyapatite has been carried out through a process of precipitation of calcium hydroxide (Ca(OH) 2 ) with phosphoric acid (H 3 PO 4 ) based on acid base reaction process that produce crystalline solid and then it will be used for binder tungstate in 188 W/ 188 Re generator system. The purpose of this study were to characterize the results of synthesized hydroxyapatite and to determine the optimum conditions on generator 188 W/ 188 Re performance such as activation of the heating hydroxyapatite, pH of Na 2 WO 4 , reaction temperature, distribution coefficient and the adsorption capacity (adsorption coefficient) of hydroxyapatite. The characterization of synthesized hydroxyapatite was done using FTIR, XRD and SEM-EDAX, while the determination of the optimum condition of each parameters based on distribution coefficient and adsorption capacity hydroxyapatite using spectrophotometric method. The FTIR results of hydroxyapatite (Ca 10 (PO 4 ) 6 (OH) 2 ) showed the appearance of peaks in the O-H stretching wave number (υ) and 3434.9 cm -1 and 563.8 cm -1 , while the group PO 4 -3 is shown by the P-O bond in (υ) 1033.8 cm -1 . The XRD results indicate that hydroxyapatite had three peaks at 2θ region is 31,875° , 32,205° and 33,080°. Characterization by SEM showed columnar morphology with a particle size of 200 nm. The optimum conditions of each parameter obtained at hydroxyapatite heating temperature 100 °C, Na 2 WO 4 solution pH 3, and the reaction temperature of 60 °C, which gave result on distribution coefficients of 193.74 mL/g and adsorption capacity (adsorption coefficient) of 5.20 mg W/g HAp. (author)

  9. On tungstates of divalent cations (II). Polymorphy of Pb{sub 2}WO{sub 5}

    Energy Technology Data Exchange (ETDEWEB)

    Jantz, Stephan G.; Dialer, Marwin; Hoeppe, Henning A. [Lehrstuhl fuer Festkoerperchemie, Universitaet Augsburg (Germany); Pielnhofer, Florian [Abteilung Nanochemie, Max-Planck-Institut fuer Festkoerperforschung, Stuttgart (Germany)

    2017-12-13

    The phase transition from the low temperature form Pb{sub 2}[WO{sub 5}] to its high temperature form Pb{sub 2}O[WO{sub 4}] was monitored by means of temperature dependent powder XRD. Single-crystals of Pb{sub 2}[WO{sub 5}], suitable for a structure determination by single-crystal X-ray diffraction, were obtained by quenching a sample from 500 C to room temperature. The low-temperature phase Pb{sub 2}[WO{sub 5}] comprises the structural motive of infinite zigzag chains built by cornersharing WO{sub 6} octahedra, known from the tungstates M{sub 2}[WO{sub 5}] (M = Sr, Ba), but crystallizes in a new structure type [C2/c, a = 14.0996(4) Aa, b = 5.8579(2) Aa, c = 12.6877(4) Aa, β = 114.3569(13) , Z = 8, R{sub int} = 0.042, R{sub 1} = 0.040, wR{sub 2} = 0.068]. The crystal structure of the high-temperature phase Pb{sub 2}O[WO{sub 4}] [C2/m, a = 14.2126(4) Aa, b = 5.80150(10) Aa, c = 7.3477(2) Aa, β = 113.9402(7) , Z = 4, R{sub 1} = 0.035, wR{sub 2} = 0.055] is revised, based on single-crystal XRD data. Furthermore spectroscopic data (IR, Raman and UV/Vis spectra) are presented. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  10. Some peculiarities of zirconium tungstate synthesis by thermal decomposition of hydrothermal precursors

    Energy Technology Data Exchange (ETDEWEB)

    Gubanov, Alexander I., E-mail: gubanov@niic.nsc.su [Nikolaev Institute of Inorganic Chemistry, Siberian Branch of the Russian Academy of Sciences, Akad. Lavrentiev Prospekt 3, 630090 Novosibirsk (Russian Federation); Novosibirsk State University, Pirogova str. 2, 630090 Novosibirsk (Russian Federation); Dedova, Elena S. [Institute of Strength Physics and Materials Science, Siberian Branch of the Russian Academy of Sciences, pr. Akademicheskii 2/4, 634021 Tomsk (Russian Federation); Tomsk Polytechnic University, Lenin Avenue 30, 634050 Tomsk (Russian Federation); Plyusnin, Pavel E.; Filatov, Eugeny Y. [Nikolaev Institute of Inorganic Chemistry, Siberian Branch of the Russian Academy of Sciences, Akad. Lavrentiev Prospekt 3, 630090 Novosibirsk (Russian Federation); Novosibirsk State University, Pirogova str. 2, 630090 Novosibirsk (Russian Federation); Kardash, Tatyana Y. [Boreskov Institute of Catalysis, Siberian Branch of the Russian Academy of Sciences, Akad. Lavrentiev Prospekt 5, 630090 Novosibirsk (Russian Federation); Korenev, Sergey V. [Nikolaev Institute of Inorganic Chemistry, Siberian Branch of the Russian Academy of Sciences, Akad. Lavrentiev Prospekt 3, 630090 Novosibirsk (Russian Federation); Novosibirsk State University, Pirogova str. 2, 630090 Novosibirsk (Russian Federation); Kulkov, Sergey N. [Institute of Strength Physics and Materials Science, Siberian Branch of the Russian Academy of Sciences, pr. Akademicheskii 2/4, 634021 Tomsk (Russian Federation); Tomsk Polytechnic University, Lenin Avenue 30, 634050 Tomsk (Russian Federation)

    2014-12-10

    Highlights: • Synthesis of ZrW{sub 2}O{sub 8} using hydrothermal method. • On hydrothermal synthesis optimal conc. of HCl in the reaction mixture is 2.3 M. • Thermal decomposition of ZrW{sub 2}O{sub 7}((OH){sub 1.5},Cl{sub 0.5})·2H{sub 2}O begins are 200 °S. • Amorphous intermediate crystallizes into cubic single-phase ZrW{sub 2}O{sub 8} above 550 °S. • ZrW{sub 2}O{sub 8} destructed at temperatures above 700 °S. - Abstract: This article discusses some peculiarities of the synthesis of ZrW{sub 2}O{sub 8} (1) using thermal decomposition of the precursor ZrW{sub 2}O{sub 7}((OH){sub 1.5},Cl{sub 0.5})·2H{sub 2}O (2) prepared by hydrothermal method. On hydrothermal synthesis of 2 the optimal concentration of hydrochloric acid in the reaction mixture is about 2.3 M. TG approach to determine the chemical composition of the precursor was suggested. It has been found that the precursor for the synthesis of zirconium tungstate has chemical formula 2. Thermal decomposition of the precursor 2 begins at 200 °S and affords an amorphous intermediate, which crystallizes as a cubic phase 1 above 550 °S with an exoeffect. The temperature of the beginning of the transition from amorphous to the crystalline state is 350 ± 25 °S.

  11. Synthesis of diblock copolymers comprising poly(2-vinylpyridine-co-acrylonitrile) and polystyrene blocks by nitroxide-mediated radical polymerization

    Czech Academy of Sciences Publication Activity Database

    Lokaj, Jan; Poláková, Lenka; Holler, Petr; Starovoytova, Larisa; Štěpánek, Petr; Diat, O.

    2007-01-01

    Roč. 105, č. 3 (2007), s. 1616-1622 ISSN 0021-8995 R&D Projects: GA ČR GESON/03/E001 Institutional research plan: CEZ:AV0Z40500505 Keywords : 2-vinylpyridine-acrylonitrile copolymers * nitroxide-mediated radical copolymerization * chain extension Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.008, year: 2007

  12. Ultrasonic velocity and absorption study of binary mixtures of cyclohexane with acrylonitrile by interferometric method at different frequencies

    Science.gov (United States)

    Pawar, N. R.; Chimankar, O. P.; Bhandakkar, V. D.; Padole, N. N.

    2012-12-01

    The ultrasonic velocity (u), absorption (α), density (ρ), and viscosity (η) has been measured at different frequencies (1MHz to 10MHz) in the binary mixtures of cyclohexane with acrylonitriile over the entire range of composition at temperature 303K. Vander Waal's constant (b), adiabatic compressibility (βa), acoustic impedance (Z), molar volume (V), free length (Lf), free volume, internal pressure, intermolecular radius and relative association have been also calculated. A special application for acrylonitrile is in the manufacture of carbon fibers. These are produced by paralysis of oriented poly acrylonitrile fibers and are used to reinforce composites for high-performance applications in the aircraft, defense and aerospace industries. Other applications of acrylonitrile are in the production of fatty amines, ion exchange resins and fatty amine amides used in cosmetics, adhesives, corrosion inhibitors and water-treatment resins. Cyclohexane derivatives can be used for the synthesis of pharmaceuticals, dyes, herbicides, plant growth regulator, plasticizers, rubber chemicals, nylon, cyclamens and other organic compounds. In the view of these extensive applications of acrylonitrile and cyclohexane in the engineering process, textile and pharmaceutical industries present study provides qualitative information regarding the nature and strength of interaction in the liquid mixtures through derive parameters from ultrasonic velocity and absorption measurement.

  13. Synthesis and gas permeability of block copolymers composed of poly(styrene-co-acrylonitrile) and polystyrene blocks

    Czech Academy of Sciences Publication Activity Database

    Lokaj, Jan; Brožová, Libuše; Holler, Petr; Pientka, Zbyněk

    2002-01-01

    Roč. 67, č. 2 (2002), s. 267-278 ISSN 0010-0765 R&D Projects: GA ČR GA203/99/0572 Institutional research plan: CEZ:AV0Z4050913 Keywords : azeotropic styrene-acrylonitrile copolymers * block copolymers * nitroxide-mediated copolymerization Subject RIV: CD - Macromolecular Chemistry Impact factor: 0.848, year: 2002

  14. Fuel oil from acrylonitrile-butadiene-styrene copolymers using a tandem PEG-enhanced denitrogenation-pyrolysis method

    NARCIS (Netherlands)

    Zhou, Q.; Yang, J.W.; Du, A.K.; Wang, Y.Z.; Kasteren, van J.M.N.

    2009-01-01

    Acrylonitrile-butadiene-styrene (ABS) was treated using a tandem poly(ethylene glycol) (PEG)-enhanced alkaline denitrogenation-pyrolysis method according to the structure and thermal degradation properties of ABS. This denitrogenated ABS (DABS) were pyrolyzed to produce clean fuels, such as fuel

  15. Optimization of the scintillation parameters of the lead tungstate crystals for their application in high precision electromagnetic calorimetry; Optimisation des parametres de scintillation des cristaux de tungstate de plomb pour leur application dans la calorimetrie electromagnetique de haute precision

    Energy Technology Data Exchange (ETDEWEB)

    Drobychev, G

    2000-04-12

    In the frame of this dissertation work scintillation properties of the lead tungstate crystals (PWO) and possibilities of their use were studied foreseeing their application for electromagnetic calorimetry in extreme radiation environment conditions of new colliders. The results of this work can be summarized in the following way. 1. A model of the scintillations origin in the lead tungstate crystals which includes processes influencing on the crystals radiation hardness and presence of slow components in scintillations was developed. 2. An analysis of the influences of the PWO scintillation properties changes on the parameters of the electromagnetic calorimeter was done. 3. Methods of the light collection from the large scintillation elements of complex shape made of the birefringent scintillation crystal with high refraction index and low light yield in case of signal registration by a photodetector with sensitive surface small in compare with the output face of scintillator were Studied. 4. Physical principles of the methodology of the scintillation crystals certification during their mass production foreseeing their installation into a calorimeter electromagnetic were developed. Correlations between the results of measurements of the PWO crystals parameters by different methods were found. (author)

  16. Synergetic effect of copper-plating wastewater as a catalyst for the destruction of acrylonitrile wastewater in supercritical water oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Young Ho; Lee, Hong-shik; Lee, Young-Ho [School of Chemical and Biological Engineering and Institute of Chemical Processes, Seoul National University, 599 Gwanangno, Gwanak-gu, Seoul 151-744 (Korea, Republic of); Kim, Jaehoon; Kim, Jae-Duck [Supercritical Fluid Research Laboratory, Energy and Environment Research Division, Korea Institute of Science and Technology (KIST), 39-1 Hawolgok-dong, Seongbuk-gu, Seoul 136-791 (Korea, Republic of); Lee, Youn-Woo, E-mail: ywlee@snu.ac.kr [School of Chemical and Biological Engineering and Institute of Chemical Processes, Seoul National University, 599 Gwanangno, Gwanak-gu, Seoul 151-744 (Korea, Republic of)

    2009-08-15

    A new supercritical water oxidation process for the simultaneous treatment of mixed wastewater containing wastewater from acrylonitrile manufacturing processes and copper-plating processes was investigated using a continuous tubular reactor system. Experiments were carried out at temperatures ranging from 400 to 600 deg. C and a pressure of 25 MPa. The residence time was fixed at 2 s by changing the flow rates of feeds, depending on reaction temperature. The initial total organic carbon (TOC) concentration of the wastewaters and the O{sub 2} concentration at the reactor inlet were kept constant at 0.49 and 0.74 mol/L. It was confirmed that the copper-plating wastewater accelerated the TOC conversion of acrylonitrile wastewater from 17.6% to 67.3% at a temperature of 450 deg. C. Moreover, copper and copper oxide nanoparticles were generated in the process of supercritical water oxidation (SCWO) of mixed wastewater. 99.8% of copper in mixed wastewater was recovered as solid copper and copper oxides at a temperature of 600 deg. C, with their average sizes ranging from 150 to 160 nm. Our study showed that SCWO provides a synergetic effect for simultaneous treatment of acrylonitrile and copper-plating wastewater. During the reaction, the oxidation rate of acrylonitrile wastewater was enhanced due to the in situ formation of nano-catalysts of copper and/or copper oxides, while the exothermic decomposition of acrylonitrile wastewater supplied enough heat for the recovery of solid copper and copper oxides from copper-plating wastewater. The synergetic effect of wastewater treatment by the newly proposed SCWO process leads to full TOC conversion, color removal, detoxification, and odor elimination, as well as full recovery of copper.

  17. Progress in the Development of the Lead Tungstate Crystals for EM-Calorimetry in High-Energy Physics

    Science.gov (United States)

    Novotny, R. W.; Brinkmann, K.-T.; Borisevich, A.; Dormenev, V.; Houzvicka, J.; Korjik, M.; Zaunick, H.-G.

    2017-11-01

    Even at present time there is a strong interest and demand for high quality lead tungstate crystals (PbWO4, PWO) for electromagnetic (EM) calorimetry. PWO is implemented into the EM calorimeter of the CMS-ECAL detector at LHC [1] and required for the completion of the PANDA EMC [2] and various ongoing detector projects at Jefferson Lab. The successful mass production of PWO using the Czochralski method was stopped after bankruptcy of the Bogoroditsk Technical Chemical Plant (BTCP) in Russia as major producer so far. The Shanghai Institute of Ceramics, Chinese Academy of Science (China) was considered as an alternative producer using the modified Bridgman method. The company CRYTUR (Turnov, Czech Republic) with good experience in the development and production of different types of inorganic oxide crystals has restarted at the end of 2014 the development of lead tungstate for mass production based on the Czochralski method. An impressive progress was achieved since then. The growing technology was optimized to produce full size samples with the quality meeting the PANDA-EMC specifications for PWO-II. We will present a detailed progress report on the research program in collaboration with groups at Orsay and JLab. The full size crystals will be characterized with respect to optical performance, light yield, kinetics and radiation hardness.

  18. Optimization of the scintillation parameters of the lead tungstate crystals for their application in high precision electromagnetic calorimetry

    International Nuclear Information System (INIS)

    Drobychev, G.

    2000-01-01

    In the frame of this dissertation work scintillation properties of the lead tungstate crystals PWO) and possibilities of their use were studied foreseeing their application for electromagnetic calorimetry in extreme radiation environment conditions of new colliders. The results of this work can be summarized in the following way. 1. A model of the scintillations origin in the lead tungstate crystals which includes processes influencing on the crystals radiation hardness and presence of slow components in scintillations was developed. 2. An analysis of the influences of the PWO scintillation properties changes on the parameters of the electromagnetic calorimeter was done. 3. Methods of the light collection from the large scintillation elements of complex shape made of the birefringent scintillation crystal with high refraction index and low light yield in case of signal registration by a photodetector with sensitive surface small in compare with the output face of scintillator were Studied. 4. Physical principles of the methodology of the scintillation crystals certification during their mass production foreseeing their installation into a calorimeter electromagnetic were developed. Correlations between the results of measurements of the PWO crystals parameters by different methods were found. (author)

  19. A comparative study of ion exchange properties of antimony (III) tungstoselenite with those of antimony (III) tungstate and antimony (III) selenite

    International Nuclear Information System (INIS)

    Janardanan, C.; Nair, S.M.K.

    1996-01-01

    A new inorganic ion exchanger, antimony (III) tungstoselenite, has been prepared and characterised. Its exchange capacity and distribution coefficients for various metal ions and the effects of temperature and electrolyte concentrations on ion exchange capacity have been compared with antimony (III) tungstate and antimony (III) selenite. Six binary separations using the exchanger have been carried out. (author). 7 refs., 1 tab

  20. Low-temperature flux growth of sulfates, molybdates, and tungstates of Ca, Sr, and Ba and investigation of doping with Mn6+

    NARCIS (Netherlands)

    Romanyuk, Y.E.; Ehrentraut, D.; Pollnau, Markus; Garcia-Revilla, S.; Valiente, R.

    The growth of undoped and $Mn^{6+}$-doped molybdates and tungstates of alkali-earth metals and BaSO4 has been investigated. Single crystals were grown by the flux method within the temperature range of 600–475 °C, using the ternary NaCl–KCl–CsCl solvent. Sizes of undoped crystals increase within the

  1. Design and length optimization of an adiabatic coupler for on-chip vertical integration of rare-earth-doped double tungstate waveguide amplifiers

    NARCIS (Netherlands)

    Mu, Jinfeng; Sefünç, Mustafa; García Blanco, Sonia Maria

    2014-01-01

    The integration of rare-earth doped double tungstate waveguide amplifiers onto passive technology platforms enables the on-chip amplification of very high bit rate signals. In this work, a methodology for the optimized design of vertical adiabatic couplers between a passive Si3N4 waveguide and the

  2. Modification on liquid retention property of cassava starch by radiation grafting with acrylonitrile: Pt. 1

    International Nuclear Information System (INIS)

    Kiatkamjornwong, S.; Nakason, C.; Chvajarempun, J.

    1993-01-01

    Radiation modification on liquid retention properties of native cassava starch, gelatinized at 85 o C, by graft copolymerization with acrylonitrile was carried out by mutual irradiation to gamma-rays. A thin aluminium foil was used to cover the inner wall of the reaction vessel, so that the homopolymer concentration was reduced to be less than 1.0% with a distilled water retention value of 665 g/g of the dry weight of the saponified grafted product. Confirmation of graft copolymerization and saponification reactions was made by the infrared spectrophotometric technique. The combined effect of radiation parameters in terms of an irradiation time and a dose rate to the total dose on the extent of the grafting reaction expressed in terms of grafting parameters which directly influenced liquid retention values was evaluated in conjunction with statistical analysis. (author)

  3. Experimental study on behaviors of dielectric elastomer based on acrylonitrile butadiene rubber

    Science.gov (United States)

    An, Kuangjun; Chuc, Nguyen Huu; Kwon, Hyeok Yong; Phuc, Vuong Hong; Koo, Jachoon; Lee, Youngkwan; Nam, Jaedo; Choi, Hyouk Ryeol

    2010-04-01

    Previously, the dielectric elastomer based on Acrylonitrile Butadiene Rubber (NBR), called synthetic elastomer has been reported by our group. It has the advantages that its characteristics can be modified according to the requirements of performances, and thus, it is applicable to a wide variety of applications. In this paper, we address the effects of additives and vulcanization conditions on the overall performance of synthetic elastomer. In the present work, factors to have effects on the performances are extracted, e.g additives such as dioctyl phthalate (DOP), barium titanium dioxide (BaTiO3) and vulcanization conditions such as dicumyl peroxide (DCP), cross-linking times. Also, it is described how the performances can be optimized by using DOE (Design of Experiments) technique and experimental results are analyzed by ANOVA (Analysis of variance).

  4. Stretchable Fluorescent Polyfluorene/Acrylonitrile Butadiene Rubber Blend Electrospun Fibers through Physical Interaction and Geometrical Confinement.

    Science.gov (United States)

    Hsieh, Hui-Ching; Chen, Jung-Yao; Lee, Wen-Ya; Bera, Debaditya; Chen, Wen-Chang

    2018-03-01

    Stretchable light-emitting polymers are important for wearable electronics; however, the development of intrinsic stretchable light-emitting materials with great performance under large applied strain is the most critical challenge. Herein, this study demonstrates the fabrication of stretchable fluorescent poly[(9,9-bis(3'-(N,N-dimethylamino)propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctyl-fluorene)]/acrylonitrile butadiene rubber (PFN/NBR) blend nanofibers using the uniaxial electrospinning technique. The physical interaction of PFN with NBR and the geometrical confinement of nanofibers are employed to reduce PFN aggregation, leading to the high photoluminescence quantum yield of 35.7%. Such fiber mat film shows stable blue emission at the 50% strain for 200 stretching/release cycles, which has potential applications in smart textiles. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Innovative Application of Biopolymer Keratin as a Filler of Synthetic Acrylonitrile-Butadiene Rubber NBR

    Directory of Open Access Journals (Sweden)

    Mirosława Prochoń

    2013-01-01

    Full Text Available The current investigations show the influence of keratin, recovered from the tanning industry, on the thermal and mechanical properties of vulcanizates with synthetic rubber acrylonitrile-butadiene rubber NBR. The addition of waste protein to NBR vulcanizates influences the improvement of resistance at high temperatures and mechanical properties like tensile strength and hardness. The introduction of keratin to the mixes of rubber previously blended with zinc oxide (ZnO before vulcanization process leads to an increase in the cross-linking density of vulcanizates. The polymer materials received including addition of proteins will undergo biodecomposition in natural conditions. After soil test, vulcanizates with keratin especially keratin with ZnO showed much more changes on the surface area than vulcanizates without protein. In that aerobic environment, microorganisms, bacteria, and fungus digested better polymer materials containing natural additives.

  6. Tensile, swelling and morphological properties of bentonite-filled acrylonitrile butadiene rubber composites

    Science.gov (United States)

    Lotfi, Muhamad Nadhli Amin; Ismail, Hanafi; Othman, Nadras

    2017-10-01

    Tensile, swelling and morphological properties of bentonite filled acrylonitrile butadiene rubber (NBR/Bt) composites were studied. The experiments were conducted at room temperature by using two rolled mill, universal testing machine (INSTRON), and American Standard Testing Method (ASTM) D471 for compounding, tensile testing, and swelling test, respectively. Results obtained indicated that a better tensile strength, elongation at break and tensile modulus were recorded as compared to the pure NBR particularly up to 90 phr of Bt loading. However, swelling (%) exhibited the opposite trend where the liquid uptake by the composites was indirectly proportional with the increasing of Bt loading. Scanning electron microscopy (SEM) used on the tensile fractured surface of the NBR/Bt composites have shown that the fillers were well embedded in the NBR matrix, for Bt loading up to 90 phr. The agglomeration of fillers occurred for Bt loading exceeding 90 phr.

  7. Synthesis and thermal studies of acrylonitrile terpolymers as carbon fiber precursor

    International Nuclear Information System (INIS)

    Hakeem, W.A.; Rusli Daik; Ahmad, I.

    2010-01-01

    Acrylonitrile (AN) and 2-dimethylaminoethyl methacrylate (DMAEM) terpolymers with fumaronitrile (FN) or itaconic acid (IA) as the termonomer have been synthesized. The solvent-water suspension polymerization was carried out at 65 degree Celsius, using α, α-azobisisobutyronitrile (AIBN) as the initiator in a mixture of dimethylformamide (DMF) and deionized water. Composition of AN and DMAEM was fixed at 98:2 in all the terpolymers, while the amount of FN and IA was carried out on the terpolymers by means of Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA). The glass transition temperature (T g ), initial temperature of cyclization (T i ), heat evolved (ΔH), and the char yield of the terpolymers are compared with that of the copolymer of AN and DMAEM. (author)

  8. Certification of mercury in acrylonitrile butadiene styrene by using isotope dilution mass spectrometry

    International Nuclear Information System (INIS)

    Hu Hai; Ma Liandi; Wei Chao; Zhou Tao; Wang Jun; Zhao Motian; Li Jinying

    2008-01-01

    Under the framework of a co-certification system for the development of Certified Reference Materials (CRMs) among China, Japan and Korea, the 1st co-certification campaign of mercury in acrylonitrile butadiene styrene (ABS) for Japanese CRMs was taken. In this campaign isotope dilution mass spectrometry (IDMS) was used. First, all abundances of Hg in spike 202 Hg, CRM and ABS were analyzed by MC-ICP-MS before the certification. Then the concentrations of 202 Hg and Hg in ABS were determined with IDMS by Q-ICP-MS. A new procedure to reduce memory effect was used. first, dilute with 5 μg/g Au solution for 1 min; then, 5 μg/g EDTA solution for 2 min. The results accord to each other very well and this implies that the co-certification system can run swimmingly. (authors)

  9. Gloves against mineral oils and mechanical hazards: composites of carboxylated acrylonitrile-butadiene rubber latex.

    Science.gov (United States)

    Krzemińska, Sylwia; Rzymski, Władysław M; Malesa, Monika; Borkowska, Urszula; Oleksy, Mariusz

    2016-09-01

    Resistance to permeation of noxious chemical substances should be accompanied by resistance to mechanical factors because the glove material may be torn, cut or punctured in the workplace. This study reports on glove materials, protecting against mineral oils and mechanical hazards, made of carboxylated acrylonitrile-butadiene rubber (XNBR) latex. The obtained materials were characterized by a very high resistance of the produced materials to oil permeation (breakthrough time > 480 min). The mechanical properties, and especially tear resistance, of the studied materials were improved after the addition of modified bentonite (nanofiller) to the XNBR latex mixture. The nanocomposite meets the requirements in terms of parameters characterizing tear, abrasion, cut and puncture resistance. Therefore, the developed material may be used for the production of multifunctional protective gloves.

  10. Immobilization of catalase on poly(acrylonitrile)-g.co-hydroxyethyl methacrylate

    International Nuclear Information System (INIS)

    Cavaco, M.C.; Andrade, M.E.

    1991-01-01

    Various poly(acrylonitrile)-g.co-hydroxyethyl methacrylate graft copolymers were prepared by using gamma irradiation at 400 Gy.h -1 . The influence of monomer concentration and time of irradiation on the level of grafting were analysed. The hydrophilicity of the polymeric supports was calculated by determining the water sorption. From the results obtained, we could conclude that the hydrophilicity was dependent on the yield of grafting. Some of the graft copolymers prepared were used for the immobilization of catalase. This enzyme was covalently coupled to the hydroxyl groups of the support after activation either with epichlorohydrin or with p-toluene sulphonyl chloride. The yield of enzyme coupling increases when hexamethylenediamine was used as a 'spacer'. (author) 5 refs.; 3 figs.; 2 tabs

  11. Thermo-Physical Properties of Kenaf-Filled Acrylonitrile Butadiene Styrene Composites

    Directory of Open Access Journals (Sweden)

    Nikmatin Siti

    2017-01-01

    Full Text Available Studies on advantageous of natural fillers incorporated into polymer composites on thermo-physical and mechanical properties are still intensively investigated. Several evidences suggest that the natural fillers with small contents combined with polymer increase their composite properties. We thus investigate thermo-physical properties of kenaf-filled acrylonitrile butadiene styrene (ABS composites. ABS with 5% kenaf microparticle size (ABS/K5, ABS with 5% kenaf short fiber (ABS/KSF5, and recycled ABS with 5% kenaf microparticle size (RABS/K5 were manufactured. Granular composites were manufactured by the twin screw extruder. Composite properties in terms of X-ray diffractions, surface morphologies, and thermal behaviors were investigated. The present work found that ABS/KSF5 has the highest degree of crystallinity compared to others. No significant difference was found in terms of thermal properties of the composites.

  12. Free volume dependence on electrical properties of Poly (styrene co-acrylonitrile)/Nickel oxide polymer nanocomposites

    Science.gov (United States)

    Ningaraju, S.; Hegde, Vinayakaprasanna N.; Prakash, A. P. Gnana; Ravikumar, H. B.

    2018-04-01

    Polymer nanocomposites of Poly (styrene co-acrylonitrile)/Nickel Oxide (PSAN/NiO) have been prepared. The increased free volume sizes up to 0.4 wt% of NiO loading indicates overall reduction in packing density of polymer network. The decreased o-Ps lifetime (τ3) at higher concentration of NiO indicates improved interfacial interaction between the surface of NiO nanoparticles and side chain of PSAN polymer matrix. The increased AC/DC conductivity at lower wt% of NiO loading demonstrates increased number of electric charge carriers/mobile ions and their mobility. The increased dielectric constant and dielectric loss up to 0.4 wt% of NiO loading suggests the increased dipoles polarization.

  13. Laser micromachining of cadmium tungstate scintillator for high energy X-ray imaging

    Science.gov (United States)

    Richards, Sion Andreas

    Pulsed laser ablation has been investigated as a method for the creation of thick segmented scintillator arrays for high-energy X-ray radiography. Thick scintillators are needed to improve the X-ray absorption at high energies, while segmentation is required for spatial resolution. Monte-Carlo simulations predicted that reflections at the inter-segment walls were the greatest source of loss of scintillation photons. As a result of this, fine pitched arrays would be inefficient as the number of reflections would be significantly higher than in large pitch arrays. Nanosecond and femtosecond pulsed laser ablation was investigated as a method to segment cadmium tungstate (CdWO_4). The effect of laser parameters on the ablation mechanisms, laser induced material changes and debris produced were investigated using optical and electron microscopy, energy dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy for both types of lasers. It was determined that nanosecond ablation was unsuitable due to the large amount of cracking and a heat affected zone created during the ablation process. Femtosecond pulsed laser ablation was found to induce less damage. The optimised laser parameters for a 1028 nm laser was found to be a pulse energy of 54 μJ corresponding to a fluence of 5.3 J cm. -2 a pulse duration of 190 fs, a repetition rate of 78.3 kHz and a laser scan speed of 707 mm s. -1 achieving a normalised pulse overlap of 0.8. A serpentine scan pattern was found to minimise damage caused by anisotropic thermal expansion. Femtosecond pulsed ablation was also found to create a layer of tungsten and cadmium sub-oxides on the surface of the crystals. The CdWO_4 could be cleaned by immersing the CdWO_4 in ammonium hydroxide at 45°C for 15 minutes. However, XPS indicated that the ammonium hydroxide formed a thin layer of CdCO_3 and Cd(OH)_2 on the surface. Prototype arrays were shown to be able to resolve features as small as 0.5 mm using keV energy X-rays. The most

  14. Photoinitiated decomposition of substituted ethylenes: The photodissociation of vinyl chloride and acrylonitrile at 193 nm

    Energy Technology Data Exchange (ETDEWEB)

    Blank, D.A.; Suits, A.G.; Lee, Y.T. [Lawrence Berkeley National Lab., CA (United States)] [and others

    1997-04-01

    Ethylene and its substituted analogues (H{sub 2}CCHX) are important molecules in hydrogen combustion. As the simplest {pi}-bonded hydrocarbons these molecules serve as prototypical systems for understanding the decomposition of this important class of compounds. The authors have used the technique of photofragment translational spectroscopy at beamline 9.0.2.1 to investigate the dissociation of vinyl chloride (X=Cl) and acrylonitrile (X=CN) following absorption at 193 nm. The technique uses a molecular beam of the reactant seeded in helium which is crossed at 90 degrees with the output of an excimer laser operating on the ArF transition, 193.3 nm. The neutral photoproducts which recoil out of the molecular beam travel 15.1 cm where they are photoionized by the VUV undulator radiation, mass selected, and counted as a function of time. The molecular beam source is rotatable about the axis of the dissociation laser. The authors have directly observed all four of the following dissociation channels for both systems: (1) H{sub 2}CCHX {r_arrow} H + C{sub 2}H{sub 2}X; (2) H{sub 2}CCHX {r_arrow} X + C{sub 2}H{sub 3}; (3) H{sub 2}CCHX {r_arrow} H{sub 2} + C{sub 2}HX; and (4) H{sub 2}CCHX {r_arrow} HX + C{sub 2}H{sub 2}. They measured translational energy distributions for all of the observed channels and measured the photoionization onset for many of the photoproducts which provided information about their chemical identity and internal energy content. In the case of acrylonitrile, selective product photoionization provided the ability to discriminate between channels 2 and 4 which result in the same product mass combination.

  15. Photoinitiated decomposition of substituted ethylenes: The photodissociation of vinyl chloride and acrylonitrile at 193 nm

    International Nuclear Information System (INIS)

    Blank, D.A.; Suits, A.G.; Lee, Y.T.

    1997-01-01

    Ethylene and its substituted analogues (H 2 CCHX) are important molecules in hydrogen combustion. As the simplest π-bonded hydrocarbons these molecules serve as prototypical systems for understanding the decomposition of this important class of compounds. The authors have used the technique of photofragment translational spectroscopy at beamline 9.0.2.1 to investigate the dissociation of vinyl chloride (X=Cl) and acrylonitrile (X=CN) following absorption at 193 nm. The technique uses a molecular beam of the reactant seeded in helium which is crossed at 90 degrees with the output of an excimer laser operating on the ArF transition, 193.3 nm. The neutral photoproducts which recoil out of the molecular beam travel 15.1 cm where they are photoionized by the VUV undulator radiation, mass selected, and counted as a function of time. The molecular beam source is rotatable about the axis of the dissociation laser. The authors have directly observed all four of the following dissociation channels for both systems: (1) H 2 CCHX → H + C 2 H 2 X; (2) H 2 CCHX → X + C 2 H 3 ; (3) H 2 CCHX → H 2 + C 2 HX; and (4) H 2 CCHX → HX + C 2 H 2 . They measured translational energy distributions for all of the observed channels and measured the photoionization onset for many of the photoproducts which provided information about their chemical identity and internal energy content. In the case of acrylonitrile, selective product photoionization provided the ability to discriminate between channels 2 and 4 which result in the same product mass combination

  16. Ionizing radiation effect study by electron beam on acrylonitrile butadiene styrene - ABS terpolymer

    International Nuclear Information System (INIS)

    Landi, Tania Regina Lourenco

    2003-01-01

    The great advantage in the researches involving development has as objective to increase significantly the quality of the products. The ABS (acrylonitrile, butadiene, styrene) resins are terpolymers formed by an elastomer and two thermoplastics amorphous components. The three different monomeric units from the terpolymer ABS contribute separately to the material characteristics exhibited. The molecular stiffness originating from polystyrene and the benzene ring hanging on the chain is responsible for the flexion module ABS. The acrylonitrile and the styrene incorporated butadiene exercises strong influence in the resistance to the impact because it reduces the bonding among them. The engineering use of this terpolymer became important due their mechanical properties and mainly, for the responses of this to tensions or deformations applied. The polymeric materials, when submitted to the ionizing radiation are modified by the transference of energy to these materials, introducing excitation and ionization of the molecules, generating chemical reactions that can produce permanent modifications in the polymeric physicochemical structure. The induced modifications can result in the polymeric material degradation or crosslinking, which can result in the improvement of some properties. This work has, as objective, to study the electron beam ionizing radiation effect, at different doses, in the properties of the polymer ABS. The studied properties were: tensile strength at break, elongation at break, Izod impact strength, flexural strength, melt flow index, Vicat softening temperature and the thermic distortion temperature. Also researches on Differential Scanning Calorimetry (DSC) and Thermogravimetric Analyses (TGA) were accomplished. From the experimental results, it was showed that for doses until 500 kGy, at 22.6 kGy/s dose rate, in the presence of air, the crosslinking process of ABS prevails. (author)

  17. The adsorption of Pb(sup2+) and Cu(sup2+) onto gum ghatti-grafted poly(acrylamide-co-acrylonitrile) biodegradable hydrogel: isotherms and kinetic models

    CSIR Research Space (South Africa)

    Mittal, H

    2015-01-01

    Full Text Available A biodegradable hydrogel polymer of gum ghatti (Gg) with a copolymer mixture of acrylamide (AAm) and acrylonitrile (AN) was synthesized using the free-radical graft copolymerization technique. The effect of graft copolymerization on the surface area...

  18. Synthesis and Thermal Properties of Acrylonitrile/Butyl Acrylate/Fumaronitrile and Acrylonitrile/Ethyl Hexyl Acrylate/Fumaronitrile Terpolymers as a Potential Precursor for Carbon Fiber

    Directory of Open Access Journals (Sweden)

    Siti Nurul Ain Md Jamil

    2014-09-01

    Full Text Available A synthesis of acrylonitrile (AN/butyl acrylate (BA/fumaronitrile (FN and AN/EHA (ethyl hexyl acrylate/FN terpolymers was carried out by redox polymerization using sodium bisulfite (SBS and potassium persulphate (KPS as initiator at 40 °C. The effect of comonomers, BA and EHA and termonomer, FN on the glass transition temperature (Tg and stabilization temperature was studied using Differential Scanning Calorimetry (DSC. The degradation behavior and char yield were obtained by Thermogravimetric Analysis. The conversions of AN, comonomers (BA and EHA and FN were 55%–71%, 85%–91% and 76%–79%, respectively. It was found that with the same comonomer feed (10%, the Tg of AN/EHA copolymer was lower at 63 °C compared to AN/BA copolymer (70 °C. AN/EHA/FN terpolymer also exhibited a lower Tg at 63 °C when compared to that of the AN/BA/FN terpolymer (67 °C. By incorporating BA and EHA into a PAN system, the char yield was reduced to ~38.0% compared to that of AN (~47.7%. It was found that FN reduced the initial cyclization temperature of AN/BA/FN and AN/EHA/FN terpolymers to 228 and 221 °C, respectively, in comparison to that of AN/BA and AN/EHA copolymers (~260 °C. In addition, FN reduced the heat liberation per unit time during the stabilization process that consequently reduced the emission of volatile group during this process. As a result, the char yields of AN/BA/FN and AN/EHA/FN terpolymers are higher at ~45.1% and ~43.9%, respectively, as compared to those of AN/BA copolymer (37.1% and AN/EHA copolymer (38.0%.

  19. Synthesis and Thermal Properties of Acrylonitrile/Butyl Acrylate/Fumaronitrile and Acrylonitrile/Ethyl Hexyl Acrylate/Fumaronitrile Terpolymers as a Potential Precursor for Carbon Fiber.

    Science.gov (United States)

    Jamil, Siti Nurul Ain Md; Daik, Rusli; Ahmad, Ishak

    2014-09-01

    A synthesis of acrylonitrile (AN)/butyl acrylate (BA)/fumaronitrile (FN) and AN/EHA (ethyl hexyl acrylate)/FN terpolymers was carried out by redox polymerization using sodium bisulfite (SBS) and potassium persulphate (KPS) as initiator at 40 °C. The effect of comonomers, BA and EHA and termonomer, FN on the glass transition temperature (T g ) and stabilization temperature was studied using Differential Scanning Calorimetry (DSC). The degradation behavior and char yield were obtained by Thermogravimetric Analysis. The conversions of AN, comonomers (BA and EHA) and FN were 55%-71%, 85%-91% and 76%-79%, respectively. It was found that with the same comonomer feed (10%), the T g of AN/EHA copolymer was lower at 63 °C compared to AN/BA copolymer (70 °C). AN/EHA/FN terpolymer also exhibited a lower T g at 63 °C when compared to that of the AN/BA/FN terpolymer (67 °C). By incorporating BA and EHA into a PAN system, the char yield was reduced to ~38.0% compared to that of AN (~47.7%). It was found that FN reduced the initial cyclization temperature of AN/BA/FN and AN/EHA/FN terpolymers to 228 and 221 °C, respectively, in comparison to that of AN/BA and AN/EHA copolymers (~260 °C). In addition, FN reduced the heat liberation per unit time during the stabilization process that consequently reduced the emission of volatile group during this process. As a result, the char yields of AN/BA/FN and AN/EHA/FN terpolymers are higher at ~45.1% and ~43.9%, respectively, as compared to those of AN/BA copolymer (37.1%) and AN/EHA copolymer (38.0%).

  20. Incipient crystallization of transition-metal tungstates under microwaves probed by Raman scattering and transmission electron microscopy

    International Nuclear Information System (INIS)

    Siqueira, Kisla P. F.; Dias, Anderson

    2011-01-01

    Microwave synthesis was used to produce nanosized transition-metal tungstates in environmentally friendly conditions not yet reported by the literature: 110 and 150 °C, for times of 10 and 20 min. X-ray diffraction evidenced incipient crystallized materials, while transmission electron microscopy indicates nanostructured regions of about 2–5 nm inside an amorphous matrix. Raman spectroscopy was used to probe short-range ordering in the achieved samples and also to obtain a reliable set of spectra containing all the Raman-active bands predicted by group-theory calculations. The vibrational spectra showed no extra feature, indicating that the microwave processing was able to produce short-range ordered materials without tetrahedral distortions. These distortions are frequently reported when commercially modified kitchen microwave units are employed. In this work, the syntheses were conducted in a commercial apparatus especially designed for fully controlled temperature–time–pressure conditions.

  1. Synthesis and quaternization of nitroxide-terminated poly(4-vinylpyridine-co-acrylonitrile) macroinitiators and related diblock copolymers

    Czech Academy of Sciences Publication Activity Database

    Poláková, Lenka; Lokaj, Jan; Holler, Petr; Starovoytova, Larisa; Pekárek, Michal; Štěpánek, Petr

    -, 065 (2010), s. 1-10 ISSN 1618-7229 R&D Projects: GA ČR GESON/06/E005; GA ČR GA203/07/0659 Institutional research plan: CEZ:AV0Z40500505 Keywords : 4-vinylpyridine-acrylonitrile copolymers * block copolymers * nitroxide-mediated radical polymerization Subject RIV: CD - Macromolecular Chemistry Impact factor: 0.574, year: 2010 http://www.e-polymers.org/journal/papers/lpolakova_240710.pdf

  2. Influence of La/W ratio on electrical conductivity of lanthanum tungstate with high La/W ratio

    International Nuclear Information System (INIS)

    Kojo, Gen; Shono, Yohei; Ushiyama, Hiroshi; Oshima, Yoshito; Otomo, Junichiro

    2017-01-01

    The proton-conducting properties of lanthanum tungstates (LWOs) with high La/W ratios were investigated using electrochemical measurements and quantum chemical calculations. Single phases of LWOs with high La/W ratios (6.3≤La/W≤6.7) were synthesized by high-temperature sintering at around 1700 °C. The electrical conductivity of LWO increased with increasing La/W ratio in the single-phase region. The LWO synthesized at the optimum sintering temperature and time, and with the optimum La/W ratio gave the maximum conductivity, i.e., 2.7×10 −3 S cm −1 with La/W=6.7 at 500 °C. Density functional theory calculations, using the nudged elastic band method, were performed to investigate the proton diffusion barrier. The results suggest that the proton diffusion paths around La sites have the lowest proton diffusion barrier. These findings improve our understanding of LWO synthesis and the proton-conducting mechanism and provide a strategy for improving proton conduction in LWOs. - Graphical abstract: The LWOs with high La/W ratios were synthesized for the first time. The optimum La/W ratio gave the maximum conductivity with La/W=6.7 at 500 °C. The proton diffusion paths were also considered with density functional theory calculations. - Highlights: • The proton-conducting properties of lanthanum tungstates (LWOs) were investigated. • Single phase LWOs with high La/W ratios (6.3≤La/W≤6.7) were synthesized successfully. • LWOs with the high La/W ratios showed high proton conductivity. • The DFT calculation suggested the lowest proton diffusion barrier in the path around La sites.

  3. Structural characterization of hydrogen separating membranes based on lanthanide-tungstates

    International Nuclear Information System (INIS)

    Scherb, Tobias

    2011-01-01

    The global energy supply is currently the most controversial issue discussed in our society. Despite the increasing importance of renewable energies, the largest portion of electrical energy has its origin in fossil fuels. CO 2 , emitted during combustion in power plants is known to be one of the greenhouse gases that contributes significantly to global climate change. The development of technologies for environmentally friendly power generation from coal and gas is an area of significant interest. One possibility is the capture and long-term storage of CO 2 from the exhaust stream of fossil fuel power plants. In the pre-combustion process, CO 2 and H 2 can be separated after gasification of the fossil fuel. For this purpose gas-tight ceramic membranes with mixed electronic-protonic conductivity can be used. However, these materials have high requirements due to the extreme conditions in power plants. Mixed electronic-protonic conducting lanthanide tungstates (Ln 6 WO 12 Ln = lanthanide or yttrium) are promising materials, which are stable in CO 2 -containing harsh environments. This work presents a study on structure-property relationships of Ln 6 WO 12 . The structural analysis was performed by the use of neutron and high-resolution X-ray diffraction methods for three exemplary systems (Ln = La, Nd, Y). Samples were prepared via solid state reaction (SSR), and also via a sol-gel approach (Pechini). For the systems LaWO and NdWO, new structural models were developed by combined Rietveld analysis and Fourier density maps. The latter was applied to determine the electron and nuclear density distribution. LaWO with a La/W ratio from 5.3 to 5.7 crystallizes with the space group F-43m and forms a superstructure due to a partially ordered arrangement of cations. On Wyckoff site 48h, up to 4.6 % W can be substituted by La. The oxygen atoms around tungsten are highly delocalized and 6 out of 24 possible split positions are occupied. Thus, W has an octahedral coordination

  4. Improved Method for Preparation of Amidoxime Modified Poly(acrylonitrile-co-acrylic acid: Characterizations and Adsorption Case Study

    Directory of Open Access Journals (Sweden)

    Nur Amirah Mohd Zahri

    2015-07-01

    Full Text Available Redox polymerization of poly(acrylonitrile-co-acrylic acid (poly(AN-co-AA is performed at 40 °C under N2 gas by varying the ratio of acrylonitrile (AN and acrylic acid (AA in the feed. The yield production of poly(acrylonitrile (PAN is 73% and poly(AN-co-AA with a feed ratio of 93:7 is the highest yield (72%. The PAN and poly(AN-co-AA are further chemically modify with hydroxylamine hydrochloride. The FTIR spectroscopy is used to confirm the copolymerization of poly(AN-co-AA and chemical modification of poly(AN-co-AA. Elemental microanalysis shows that the overall trend percentage of carbon, hydrogen, and nitrogen for all feed ratios are slightly decreasing as the feed ratio of AA is increasing except for poly(AN-co-AA 93:7. The SEM images shows that spherical diameter of poly(AN-co-AA is smaller compared to the PAN and amidoxime (AO modified poly(AN-co-AA. The TGA (thermogravimetric analysis analysis reveals that the poly(AN-co-AA degrades at lower temperatures compared to the PAN but higher than AO modified poly(AN-co-AA. The case study adsorption test showed that the AO modified poly(AN-co-AA 93:7 had the highest percentage removal of Cd2+ and Pb2+.

  5. Preparation and evaluation of some investigated natural and acrylonitrile rubber vulcanizations for physiotherapeutic purposes

    International Nuclear Information System (INIS)

    Helaly, F.M; El-Sawy, S.M.

    2005-01-01

    A trial was made to design and prepare rubber article that can be used to reactivate, strengthen and reinforce the hand muscles and fingers which had suffered from trouble movement.The investigated rubber article was prepared from natural and acrylonitrile rubber formulations. These formulations were processed in the form of compounds which contain significant quantities of fillers as Hisil, CaCO 3 and TiO 2 .The rheological characteristics and physicochemical properties of the vulcanizations were determined according to standard tests. It was found that it is possible to prepare the designated rubber article for the desired purpose. The test results show that the prepared rubber article has a good chemical resistant against acid, alkali, and salt. Also it possesses high resistance to deterioration and deformation. The prepared article has an ability to retain its elastic property after the action of compressive forces at 70 degree C for 24 hours.This was conformed with applied commercial hand exercise therapeutic article

  6. Poly (acrylonitrile-co-methyl methacrylate nanoparticles: I. Preparation and characterization

    Directory of Open Access Journals (Sweden)

    M.S. Mohy Eldin

    2017-12-01

    Full Text Available This work concerns the preparation and characterization of poly (acrylonitrile-co-methyl methacrylate Copolymer, P(AN-co-MMA, nano-particles using precipitation polymerization technique. Potassium per-sulfate redox initiation system was used to perform polymerization process in an alcoholic aqueous system. The impact of different polymerization conditions such as comonomer concentration and ratio, polymerization time, polymerization temperatures, initiator concentration and co-solvent composition on the polymerization yield and particle size was studied. Maximum polymerization yield, 70%, was obtained with MMA:AN (90%:10% comonomer composition. Particle sizes ranging from 16 nm to 1483 nm were obtained and controlled by variation of polymerization conditions. The co-polymerization process was approved by FT-IR and TGA analysis. The copolymer composition was investigated by nitrogen content analysis. Copolymers with a progressive percentage of PAN show thermal stabilities close to PAN Homopolymer. SEM photographs prove spherical structure of the produced copolymers. The investigated system shows promising future in the preparation of nanoparticles from comonomers without using emulsifiers or dispersive agents.

  7. Synergetic effect of graphene oxide-carbon nanotube on nanomechanical properties of acrylonitrile butadiene styrene nanocomposites

    Science.gov (United States)

    Jyoti, Jeevan; Pratap Singh, Bhanu; Chockalingam, Sreekumar; Joshi, Amish G.; Gupta, Tejendra K.; Dhakate, S. R.

    2018-04-01

    Herein, multiwall carbon nanotubes (MWCNTs), reduced graphene oxide (rGO), graphene oxide-carbon nanotubes (GCNTs) hybrid reinforced acrylonitrile butadiene styrene (ABS) nanocomposites have been prepared by micro twin screw extruder with back flow channel and the effect of different type of fillers on the nanomechanical properties are studied. The combination of both graphene oxide and CNT has enhanced the dispersion in polymer matrix and lower the probability of CNTs aggregation. GCNTs hybrid have been synthesized via novel chemical route and well characterized using Raman spectroscopic technique. The nanoindentation hardness and elastic modulus of GCNTs-ABS hybrid nanocomposites were improved from 211.3 MPa and 4.12 GPa of neat ABS to 298.9 MPa and 6.02 GPa, respectively at 5wt% GCNTs loading. In addition to hardness and elastic modulus, other mechanical properties i.e. plastic index parameter, elastic recovery, ratio of residual displacement after load removal and displacement at the maximum load and plastic deformation energy have also been investigated. These results were correlated with Raman and X-ray photoelectron spectroscopic (XPS) techniques and microstructural characterizations (scanning electron microscopy). Our demonstration would provide guidelines for the fabrication of hard and scratches nanocomposite materials for potential use in, automotive trim components and bumper bars, carrying cases and electronic industries and electromagnetic interference shielding.

  8. Latex stage blending of multiwalled carbon nanotube in carboxylated acrylonitrile butadiene rubber: Mechanical and electrical properties

    International Nuclear Information System (INIS)

    Preetha Nair, K.; Thomas, Paulbert; Joseph, Rani

    2012-01-01

    Highlights: ► MWCNT can act as a reinforcing filler in XNBR at very low concentration. ► SEM and XRD analysis confirm uniform distribution of nanotube in the matrix. ► Mechanical properties showed considerable improvement. ► Thermal stability of the composite is marginally improved. -- Abstract: Multiwalled carbon nanotube (MWCNT) was dispersed in sodium dodecyl benzene sulphonate (SDBS) by sonication. The dispersed MWCNT (0.05–0.3 gm) was incorporated in carboxylated acrylonitrile butadiene rubber (XNBR) latex. Mechanical, electrical and thermal properties of these composites were studied. Mechanical properties of the composites increased up to an optimum concentration and then decreased. Dielectric properties of the composites were studied in the S band (frequency range 2–4 GHz) by Cavity Perturbation method. Direct current (DC) electrical conductivity shows a percolation behaviour and conductivity increased by about 10 orders of magnitude. Thermal studies were conducted using Differential Scanning Calorimetry (DSC) and Thermo Gravimetric Analysis (TGA). As expected with the very small concentration of multiwalled carbon nanotube, glass transition temperature (T g ) and thermal stability of the composite showed a marginal increase. Composites were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and Scanning electron microscope (SEM) analysis.

  9. THERMAL DECOMPOSITION AND FLAMMABILITY OF ACRYLONITRILE-BUTADIENE-STYRENE/MULTI-WALLED CARBON NANOTUBES COMPOSITES

    Institute of Scientific and Technical Information of China (English)

    Li-fang Tong; Hai-yun Ma; Zheng-ping Fang

    2008-01-01

    Thermal and flammability properties of acrylonitrile-butadiene-styrene copolymer (ABS) with the addition of multi-walled carbon nanotubes (MWNTs) were studied. ABS/MWNTs composites were prepared via melt blending with the MWNTs content varied from 0.2% to 4.0% by mass. Thermogravimetry results showed that the addition of MWNTs accelerated the degradation of ABS during the whole process under air atmosphere, and both onset and maximum degradation temperature were lower than those of pure ABS. The destabilization effect of MWNTs on the thermal stability of the composites became unobvious under nitrogen, and the addition of MWNTs could improve the maximum degradation temperature. The heat release rate and time of ignition (tign) for the composites reduced greatly with the addition of MWNTs especially when the concentration of nanotubes was higher than 1.0%. The accumulation of carbon nanotubes with a network structure was observed and the char layer became thicker with increasing nanotubes concentration. Results from Raman spectra showed a higher degree of graphitization for the residues of ABS/MWNTs composites.

  10. Redox polymerization of acrylonitrile-methyl acrylate-fumaronitrile terpolymer as precursor for carbon fiber

    International Nuclear Information System (INIS)

    Jamil, S.N.A.M.; Rusli Daik; Ahmad, I.

    2010-01-01

    Synthesis of acrylonitrile (AN) with methyl acrylate and fumaronitrile as comonomer and termonomer respectively, were carried out by redox polymerization using sodium bisulfite (SBS) and potassium persulphate (KPS) as initiator at 40 degree Celsius. The effect of methyl acrylate (MA) and fumaronitrile (FN) on the glass transition temperature (T g ) and stabilization temperature has been studied by Differential Scanning Calorimetry (DSC). The degradation behavior and char yield were obtained by Thermogravimetric Analysis. The T g of poly (AN/ MA) copolymers were found to be lower (∼70 degree Celsius) as compared with polyacrylonitrile (PAN) (210 degree Celsius). However, by incorporating MA into PAN system, the char yield reduced significantly. It was found that FN reduced the initial cyclization temperature of poly (AN/ MA/ FN) terpolymer to ∼230 degree Celsius as compared with poly(AN/ MA) copolymer (∼260 degree Celsius). In addition, FN reduced the heat liberation per unit time during the stabilization process that consequently reduced the emission of volatile group during this process. Thereby, the char yield of poly(AN/ MA/ FN) 90/ 4/ 6 terpolymer is higher at 51 % as compared with poly(AN/ MA) 90/ 10 copolymer (45 %). (author)

  11. Microstructure evolution and tribological properties of acrylonitrile-butadiene rubber surface modified by atmospheric plasma treatment

    Science.gov (United States)

    Shen, Ming-xue; Zhang, Zhao-xiang; Peng, Xu-dong; Lin, Xiu-zhou

    2017-09-01

    For the purpose of prolonging the service life for rubber sealing elements, the frictional behavior of acrylonitrile-butadiene rubber (NBR) surface by dielectric barrier discharge plasma treatments was investigated in this paper. Surface microstructure and chemical composition were measured by atomic force microscopy, field-emission scanning electron microscopy, and X-ray photoelectron spectroscopy, respectively. Water contact angles of the modified rubber surface were also measured to evaluate the correlation between surface wettability and tribological properties. The results show that plasma treatments can improve the properties of the NBR against friction and wear effectively, the surface microstructure and roughness of plasma-modified NBR surface had an important influence on the surface tribological behavior, and the wear depth first decreased and then increased along with the change of plasma treatment time. It was found that the wettability of the modified surface was gradually improved, which was mainly due to the change of the chemical composition after the treatment. This study suggests that the plasma treatment could effectively improve the tribological properties of the NBR surface, and also provides information for developing wear-resistant NBR for industrial applications.

  12. Zinc chelates as new activators for sulphur vulcanization of acrylonitrile-butadiene elastomer

    Directory of Open Access Journals (Sweden)

    2009-04-01

    Full Text Available The goal of this work was to apply several zinc chelates as activators for sulphur vulcanization of acrylonitrilebutadiene elastomer (NBR, in order to find alternatives for the conventionally used zinc oxide. In this article, we discuss the effects of different zinc complexes on the cure characteristics, crosslinks distribution in the elastomer network and mechanical properties of acrylonitrile-butadiene rubber. Zinc chelates seem to be good substitutes for zinc oxide as activators for sulphur vulcanization of NBR rubber, without detrimental effects on the crosslinking process and physical properties of the obtained vulcanizates. Moreover, application of zinc complexes allows to reduce the amount of zinc ions in rubber compounds by 40% compared to conventionally crosslinked vulcanizates with zinc oxide. It is a very important ecological goal since zinc oxide is classified as toxic to aquatic species and its amount in rubber products must be reduced below 2.5% at least. From a technological point of view it is a very important challenge.

  13. Study of the Effect of Grafted Antioxidant on the Acrylonitrile-Butadiene Copolymer Properties

    Directory of Open Access Journals (Sweden)

    Abdulaziz Ibrahim Al-Ghonamy

    2010-01-01

    Full Text Available The grafting of ADPEA onto natural rubber was executed with UV radiation. Benzoyl peroxide was used to initiate the free-radical grafting copolymerization. Natural rubber-graft-N-(4-aminodiphenylether acrylamide (NR-g-ADPEA was characterized with an IR technique. The paper aims interested to determine the crosslinking density by using the ultrasonic technique. The ultrasonic velocities of both longitudinal and shear waves were measured in thermoplastic discs of NBR vulcanizates as a function of aging time. Ultrasonic velocity measurements were taken at 2 MHz ultrasonic frequency using the pulse echo method. We studied the effect of aging on the mechanical properties, crosslinking density, and the swelling and extraction phenomena for acrylonitrile-butadiene copolymer (NBR vulcanizates, which contained the prepared NR-g-ADPEA and a commercial antioxidant, N-isopropyl-−-phenyl-p-phenylenediamine. The prepared antioxidant enhanced both the mechanical properties of the NBR vulcanizates and the permanence of the ingredients in these vulcanizates.

  14. An investigation on chloroprene-compatibilized acrylonitrile butadiene rubber/high density polyethylene blends.

    Science.gov (United States)

    Ahmed, Khalil

    2015-11-01

    Blends of acrylonitrile butadiene rubber/high density polyethylene (NBR/HDPE) compatibilized by Chloroprene rubber (CR) were prepared. A fixed quantity of industrial waste such as marble waste (MW, 40 phr) was also included. The effect of the blend ratio and CR on cure characteristics, mechanical and swelling properties of MW-filled NBR/HDPE blends was investigated. The results showed that the MW-filled NBR/HDPE blends revealed an increase in tensile strength, tear, modulus, hardness and cross-link density for increasing weight ratio of HDPE. The minimum torque (M L) and maximum torque (M H) of blends increased with increasing weight ratio of HDPE while scorch time (ts2) cure time (tc90), compression set and abrasion loss of blends decreased with increasing weight ratio of HDPE. The blends also showed a continuous reduction in elongation at break as well as swelling coefficient with increasing HDPE amount in blends. MW filled blends based on CR provided the most encouraging balance values of overall properties.

  15. Nanocomposites prepared from acrylonitrile butadiene rubber and organically modified montmorillonite with vinyl groups

    Science.gov (United States)

    Han, Mijeong; Kim, Hoonjung; Kim, Eunkyoung

    2006-01-01

    Nanocomposites were prepared from acrylonitrile-butadiene rubber (NBR), vinyl groups containing organically modified montmorillonite and additives, such as zinc oxide, stearic acid, and sulfur. The organically modified montmorillonites used in these nanocomposites were prepared by ion exchange reactions of N,N'-dimethylalkyl-(p-vinylbenzyl)-ammonium chlorides (DAVBAs, alkyl = octyl, dodecyl, and octadecyl) with sodium montmorillonite (Na+-MMT). NBR nanocomposites were obtained by controlling both the mixing and vulcanization conditions, by using a Brabender mixer and hot-press process. X-ray diffraction (XRD) analysis shows that, depending on the amount of montmorillonite that is added, both exfoliated and intercalated nanocomposite structures are formed. The NBR/DAVBA-MMT nanocomposites exhibit much higher mechanical properties (e.g., tensile strength, Young's modulus, 300% modulus, and hardness) as well as gas barrier properties as compared to NBR Na+-MMT or NBR composites generated from modified montmorillonites without vinyl groups. Consistent with the results of XRD, transmission electron microscopy (TEM) reveals that the intercalation and exfoliation structures of the nanocomposites coexist and that the DAVBA-MMT layers are well dispersed in NBR.

  16. Acrylonitrile-Butadiene Rubber (NBR) Prepared via Living/Controlled Radical Polymerization (RAFT).

    Science.gov (United States)

    Kaiser, Andreas; Brandau, Sven; Klimpel, Michael; Barner-Kowollik, Christopher

    2010-09-15

    In the current work we present results on the controlled/living radical copolymerization of acrylonitrile (AN) and 1,3-butadiene (BD) via reversible addition fragmentation chain transfer (RAFT) polymerization techniques. For the first time, a solution polymerization process for the synthesis of nitrile butadiene rubber (NBR) via the use of dithioacetate and trithiocarbonate RAFT agents is described. It is demonstrated that the number average molar mass, $\\overline M _{\\rm n} $, of the NBR can be varied between a few thousand and 60 000 g · mol(-1) with polydispersities between 1.2 and 2.0 (depending on the monomer to polymer conversion). Excellent agreement between the experimentally observed and the theoretically expected molar masses is found. Detailed information on the structure of the synthesized polymers is obtained by variable analytical techniques such as infrared spectroscopy (IR), nuclear magnetic resonance (NMR) spectroscopy, differential scanning calorimetry, and electrospray ionization-mass spectrometry (ESI-MS). Copyright © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. An investigation on chloroprene-compatibilized acrylonitrile butadiene rubber/high density polyethylene blends

    Directory of Open Access Journals (Sweden)

    Khalil Ahmed

    2015-11-01

    Full Text Available Blends of acrylonitrile butadiene rubber/high density polyethylene (NBR/HDPE compatibilized by Chloroprene rubber (CR were prepared. A fixed quantity of industrial waste such as marble waste (MW, 40 phr was also included. The effect of the blend ratio and CR on cure characteristics, mechanical and swelling properties of MW-filled NBR/HDPE blends was investigated. The results showed that the MW-filled NBR/HDPE blends revealed an increase in tensile strength, tear, modulus, hardness and cross-link density for increasing weight ratio of HDPE. The minimum torque (ML and maximum torque (MH of blends increased with increasing weight ratio of HDPE while scorch time (ts2 cure time (tc90, compression set and abrasion loss of blends decreased with increasing weight ratio of HDPE. The blends also showed a continuous reduction in elongation at break as well as swelling coefficient with increasing HDPE amount in blends. MW filled blends based on CR provided the most encouraging balance values of overall properties.

  18. Novel blends of acrylonitrile butadiene rubber and polyurethane-silica hybrid networks

    Directory of Open Access Journals (Sweden)

    X. P. Wang

    2012-07-01

    Full Text Available Novel blends of acrylonitrile butadiene rubber (NBR and polyurethane-silica (PU-SiO2 hybrid networks have been prepared by melt blending. The PU-SiO2 hybrid networks were formed via the reaction of NCO groups of NCO-terminated PU prepolymer and OH groups of SiO2 in the absence of an external crosslinking agent (i.e. alcohols and amines during the curing process of NBR. Both in the neat PU-SiO2 system and the NBR/(PU-SiO2 system, the NCO-terminated PU prepolymer could be crosslinked by SiO2 to form PU-SiO2 hybrid networks. The effects of PU-SiO2 introduction into the NBR, on the properties of the resulting blends were studied. It was found that the vulcanization was activated by the incorporation of PU-SiO2. Transmission electronic microscopy (TEM studies indicated that the interpenetration and entanglement structures between NBR and PU-SiO2 increased with increasing PU-SiO2 content and the quasi-interpenetrating polymer networks (quasi-IPN structures were formed when the PU-SiO2 was 50 wt% in the NBR/(PU-SiO2 systems. The microstructures formed in the blends led to good compatibility between NBR and PU-SiO2 and significantly improved the mechanical properties, abrasion resistance and flex-fatigue life of the blends.

  19. Mechanical and Morphological Properties of Short Nylon Fiber Reinforced Acrylonitrile-Butadiene Rubber Composites

    Directory of Open Access Journals (Sweden)

    S.H. Mohseniyan

    2010-12-01

    Full Text Available Acrylonitrile butadiene rubber (NBR composites are prepared from waste nylon 66 short fiber using a two-roll mill mixer. The effects of fiber content and bonding agent on the mechanical and morphological properties of the composites are studied. The curing characteristics of the composites have been studied by using cure rheometer. The cure and scorch time of the composites decrease while cure rate is increased when short fiber content is increased. The mechanical properties of the composites show improvement in both longitudinal and transverse directions with increase in short fiber content. The adhesion between the fiber and rubber is enhanced by using a dry bonding system consisting of resorcinol, xamethylenetetramine and hydrated silica (HRH. The swelling behavior of the composites in N,N-dimethylformamide is tested to find the effect of bonding agent on adhesion strength of the matrix and fibers. Fracture surface morphology of composites is studied by scanning electron microscopy. The restriction to swelling is higher for composites containing bonding agent, especially, in the longitudinal direction. The morphology of the fracture surface shows less fiber pull out when the bonding agent is introduced.

  20. Hg(II) adsorption using amidoximated porous acrylonitrile/itaconic copolymers prepared by suspended emulsion polymerization.

    Science.gov (United States)

    Ji, Chunnuan; Qu, Rongjun; Chen, Hou; Liu, Xiguang; Sun, Changmei; Ma, Caixia

    2016-01-01

    Initially, porous acrylonitrile/itaconic acid copolymers (AN/IA) were prepared by suspended emulsion polymerization. Successively, the cyano groups in AN/IA copolymers were converted to amidoxime (AO) groups by the reaction with hydroxylamine hydrochloride. The structures of the AN/IA and amidoximated AN/IA (AO AN/IA) were characterized by infrared spectroscopy, scanning electron microscopy, and porous structural analysis. The adsorption properties of AO AN/IA for Hg(II) were investigated. The results show that AO AN/IA has mesopores and macropores, and surface area of 11.71 m(2) g(-1). It was found that AO AN/IA has higher affinity for Hg(II), with the maximum adsorption capacity of 84.25 mg g(-1). The AO AN/IA also can effectively remove Hg(II) from different binary metal ion mixture systems. Furthermore, the adsorption kinetics and thermodynamics were studied in detail. The adsorption equilibrium can quickly be achieved in 4 h determined by an adsorption kinetics study. The adsorption process is found to belong to the second-order model, and can be described by the Freundlich model.

  1. Peroxydisulfate initiated synthesis of potato starch-graft-poly(acrylonitrile under microwave irradiation

    Directory of Open Access Journals (Sweden)

    2007-01-01

    Full Text Available Potato starch-graft-poly(acrylonitrile could be efficiently synthesized using small concentration of ammonium peroxydisulfate (0.0014M in aqueous medium under microwave irradiation. A representative microwave synthesized graft copolymer was characterized using Fourier Transform Infrared Spectroscopy, X-ray Diffraction, Scanning Electron Microscopy and Thermogravimetric Analysis. Under microwave conditions oxygen removal from the reaction vessel was not required and the graft copolymer was obtained in high yield using very small amount of ammonium peroxydisulfate, however using the same amount of ammonium peroxydisulfate (0.0014M on thermostatic water bath no grafting was observed up to 98°C (even in inert atmosphere. Raising the concentration of the initiator to 0.24 M resulted into 10% grafting at 50 °C but in inert atmosphere.The viscosity/shear stability of the grafted starch (aqueous solution and water/saline retention ability of the microwave synthesized graft copolymer were also studied and compared with that of the native potato starch.

  2. Kinetic studies of uranyl ion adsorption on acrylonitrile (AN) / polyethylene glycol (PEG) interpenetrating networks (IPN)

    International Nuclear Information System (INIS)

    Aycik, G.A.; Gurellier, R.

    2004-01-01

    The kinetics of the adsorption of uranyl ions on amidoximated acrylonitrile (AN)/ polyethylene glycol (PEG) interpenetrating network (IPNs) from aqueous solutions was studied as a function of time and temperature. Adsorption analyses were performed for definite uranyl ion concentrations of 1x10 -2 M and at four different temperatures as 290K, 298K, 308K and 318K. Adsorption time was increased from zero to 48 hours. Adsorption capacities of uranyl ions by PEG/AN IPNS were determined by gamma spectrometer. The results indicate that adsorption capacity increases linearly with increasing temperature. The max adsorption capacity was found as 602 mgu/g IPN at 308K. Adsorption rate was evaluated from the curve plotted of adsorption capacity versus time, for each temperature. Rate constants for uranyl ions adsorption on amidoximated ipns were calculated for 290K, 298K, 308K and 318K at the solution concentration of 1x10 -2 M . The results showed that as the temperature increases the rate constant increases exponentially too. The mean activation energy of uranyl ions adsorption was found as 34.6 kJ/mole by using arrhenius equation. (author)

  3. Synthesis of Ethylene Bis-stearamide for Acrylonitrile-Butadiene-Styrene Polymer

    Directory of Open Access Journals (Sweden)

    M.A. Sayyadnejad

    2009-12-01

    Full Text Available Ethylene bis-stearamide is one of the important acrylonitrile-butadiene-styrene (ABS( polymer additives, which is used as lubricant, slip agent and mold release agent. In this research, ethylene bis-stearamide for ABS application was synthesized using stearic acid and ethylene diamine under reflux condition. Refluxing prevented ethylenediamine from evaporation and thus the initial molar ratio was maintained unchanged. The other role of refluxing was to prevent the oxidation of ethylene diamine by removal of oxygen which might have been present inside the reactor. The synthesized samples were characterized by Fourier transform infrared spectroscopy (FTIR(, total acid number and melting point. The total acid number of the synthesized samples in the lab, bench scale 1 kg( and pilot scale 30 kg( were 6.5, 8.7 and 8.6 mgKOH/g, respectively, and their melting points were in 141-144 °C range. It was found that total acid number values of samples are inversely proportional with reaction time. The longer the reaction time, the higher was the total acid number and sample purity. Compounding was carried out using ABS containing synthesized and reference ethylene bis-stearamide and the physical-mechanical properties of the samples were measured. The obtained results showed that, the measured properties such as melt flow index, impact resistance, softening temperature, heat deflection temperature, tensile strength and hardness for the compound prepared using synthesized ethylene bis-stearamide match very well with those of reference compound.

  4. Nanostructured synthetic carbons obtained by pyrolysis of spherical acrylonitrile/divinylbenzene copolymers.

    Directory of Open Access Journals (Sweden)

    Danish J Malik

    Full Text Available Novel carbon materials have been prepared by the carbonization of acrylonitrile (AN/divinylbenzene (DVB suspension porous copolymers having nominal crosslinking degrees in the range of 30-70% and obtained in the presence of various amounts of porogens. The carbons were obtained by pre-oxidation of AN/DVB copolymers at 250-350°C in air followed by pyrolysis at 850°C in an N(2 atmosphere. Both processes were carried out in one furnace and the resulting material needed no further activation. Resulting materials were characterized by XPS and low temperature nitrogen adsorption/desorption. It was found that maximum pyrolysis yield was ca. 50% depending on the oxidation conditions but almost independent of the crosslinking degree of the polymers. Porous structure of the carbons was characterized for the presence of micropores and macropores, when obtained from highly crosslinked polymers or polymers oxidized at 350°C and meso- and macropores in all other cases. The latter pores are prevailing in the structure of carbons obtained from less porous AN/DVB resins. Specific surface area (BET of polymer derived carbons can vary between 440 m(2/g and 250 m(2/g depending on the amount of porogen used in the synthesis of the AN/DVB polymeric precursors.

  5. Crack initiation and propagation on the polymeric material ABS (Acrylonitrile Butadiene Styrene, under ultrasonic fatigue testing

    Directory of Open Access Journals (Sweden)

    G. M. Domínguez Almaraz

    2015-10-01

    Full Text Available Crack initiation and propagation have been investigated on the polymeric material ABS (Acrylonitrile Butadiene Styrene, under ultrasonic fatigue testing. Three controlled actions were implemented in order to carry out fatigue tests at very high frequency on this material of low thermal conductivity, they are: a The applying load was low to limit heat dissipation at the specimen neck section, b The dimensions of testing specimen were small (but fitting the resonance condition, in order to restraint the temperature gradient at the specimen narrow section, c Temperature at the specimen neck section was restrained by immersion in water or oil during ultrasonic fatigue testing. Experimental results are discussed on the basis of thermo-mechanical behaviour: the tail phenomenon at the initial stage of fatigue, initial shear yielding deformation, crazed development on the later stage, plastic strain on the fracture surface and the transition from low to high crack growth rate. In addition, a numerical analysis is developed to evaluate the J integral of energy dissipation and the stress intensity factor K, with the crack length

  6. Experimental Investigations on Tribological Behaviour of Alumina Added Acrylonitrile Butadiene Styrene (ABS Composites

    Directory of Open Access Journals (Sweden)

    T. Panneerselvam

    2016-09-01

    Full Text Available Composite materials are multifunctional in nature, which can be custom-made based on the nature of the applications. The challenge of composite materials lie on complementing the properties of one another i.e. materials which go in the making of composites strengthen each other by inhibiting their weaknesses. Polymers are one of the widely used materials which serve a wide spectrum of engineering needs. In the present work, the tribological behaviour of a composite containing Acrylonitrile Butadiene Styrene (ABS and traces of Alumina is experimentally investigated. Alumina is added to ABS in various percentages such as 1%, and 3% by weight in order to improve the wear resistance of the polymer. Central Composite Design was used to design the experiments and a standard Pin-On-Disk apparatus was used to conduct the experiments. It is observed from the test results that the addition of alumina significantly enhances the wear behavior of the polymer. However, adding more percentage of alumina has led to adverse effect on wear resistance of polymer materials. Abrasive wear mechanism is found to be predominant in the case of alumina added composite materials. It is also found that 1% alumina added composite exhibits excellent wear properties compared to other materials.

  7. Tensile, Creep, and Fatigue Behaviors of 3D-Printed Acrylonitrile Butadiene Styrene

    Science.gov (United States)

    Zhang, Hanyin; Cai, Linlin; Golub, Michael; Zhang, Yi; Yang, Xuehui; Schlarman, Kate; Zhang, Jing

    2018-01-01

    Acrylonitrile butadiene styrene (ABS) is a widely used thermoplastics in 3D printing. However, there is a lack of thorough investigation of the mechanical properties of 3D-printed ABS components, including orientation-dependent tensile strength and creep fatigue properties. In this work, a systematic characterization is conducted on the mechanical properties of 3D-printed ABS components. Specifically, the effect of printing orientation on the tensile and creep properties is investigated. The results show that, in tensile tests, the 0° printing orientation has the highest Young's modulus of 1.81 GPa, and ultimate strength of 224 MPa. In the creep test, the 90° printing orientation has the lowest k value of 0.2 in the plastics creep model, suggesting 90° is the most creep resistant direction. In the fatigue test, the average cycle number under load of 30 N is 3796 cycles. The average cycle number decreases to 128 cycles when the load is 60 N. Using the Paris law, with an estimated crack size of 0.75 mm, and stress intensity factor is varied from 352 to 700 N√ m, the derived fatigue crack growth rate is 0.0341 mm/cycle. This study provides important mechanical property data that is useful for applying 3D-printed ABS in engineering applications.

  8. Local pharmacological effects of tungstate on the color-pattern determination of butterfly wings: a possible relationship between the eyespot and parafocal element.

    Science.gov (United States)

    Dhungel, Bidur; Otaki, Joji M

    2009-11-01

    Butterfly wing color patterns can be changed by the application of a temperature shock or pharmacological agents such as tungstate, producing a distinctive type of elemental modification called the TS (temperature shock) type. Heterochronic uncoupling between the signaling and reception steps during the color-pattern determination process has been proposed as a mechanism for TS-type changes. As an extension of this hypothesis, both the parafocal element (PFE) and the eyespot in the same wing compartment are considered to be determined by morphogenic signal(s) emitted from the same eyespot focus. However, these models need to be examined with additional experimental data. Furthermore, there is controversy as to whether the action of tungstate on wing color patterns is direct or Indirect. Using a species of nymphalid butterfly (Junonia orithya), we have devised a simple method for the local application of pharmacological agents directly on developing wings of pupae. Local tungstate application resulted in reduced eyespots and circular dislocated PFEs in the eyespot-less compartments only on the treated wing, demonstrating that tungstate directly induces color-pattern changes on wings. We further examined the eyespot-PFE relationship in normal and cold-shocked Individuals, showing that an eyespot can be superimposed on a PFE and vice versa, probably depending on the timing of their fate determination. Taken together, we propose a two-morphogen model for the normal color-pattern determination, in which the morphogenic signals for the eyespot and PFE are different from each other despite their Identical origin. This two-morphogen model is compatible with the heterochronic uncoupling model for TS-type changes.

  9. Computational Investigation of the Competition between the Concerted Diels-Alder Reaction and Formation of Diradicals in Reactions of Acrylonitrile with Non-Polar Dienes

    Science.gov (United States)

    James, Natalie C.; Um, Joann M.; Padias, Anne B.; Hall, H. K.; Houk, K. N.

    2013-01-01

    The energetics of the Diels-Alder cycloaddition reactions of several 1,3-dienes with acrylonitrile, and the energetics of formation of diradicals, were investigated with density functional theory (B3LYP and M06-2X) and compared to experimental data. For the reaction of 2,3-dimethyl-1,3-butadiene with acrylonitrile, the concerted reaction is favored over the diradical pathway by 2.5 kcal/mol using B3LYP/6-31G(d); experimentally this reaction gives both cycloadduct and copolymer. The concerted cycloaddition of cyclopentadiene with acrylonitrile is preferred computationally over the stepwise pathway by 5.9 kcal/mol; experimentally, only the Diels-Alder adduct is formed. For the reactions of (E)-1,3-pentadiene and acrylonitrile, both cycloaddition and copolymerization were observed experimentally; these trends were mimicked by the computational results, which showed only a 1.2 kcal/mol preference for the concerted pathway. For the reactions of (Z)-1,3-pentadiene and acrylonitrile, the stepwise pathway is preferred by 3.9 kcal/mol, in agreement with previous experimental findings that only polymerization occurs. M06-2X is known to give more accurate activation and reaction energetics but the energies of diradicals are too high. PMID:23758325

  10. Analysis of acrylonitrile, 1,3-butadiene, and related compounds in acrylonitrile-butadiene-styrene copolymers for kitchen utensils and children's toys by headspace gas chromatography/mass spectrometry.

    Science.gov (United States)

    Ohno, Hiroyuki; Kawamura, Yoko

    2010-01-01

    A headspace gas chromatography/mass spectrometry method was developed for the simultaneous determination of the residual levels of acrylonitrile (AN), 1,3-butadiene (1,3-BD), and their related compounds containing propionitrile (PN) and 4-vinyl-1-cyclohexene (4-VC) in acrylonitrile-butadiene-styrene (ABS) copolymers for kitchen utensils and children's toys. A sample was cut into small pieces, then N,N-dimethylacetamide and an internal standard were added in a sealed headspace vial. The vial was incubated for 1 h at 90 degrees C and the headspace gas was analyzed by gas chromatography/mass spectrometry. The recovery rates of the analytes were 93.3-101.8% and the coefficients of variation were 0.3-6.5%. In ABS copolymers, the levels were 0.3-50.4 microg/g for AN, ND-4.5 microg/g for PN, 0.06-1.58 microg/g for 1,3-BD, and 1.1-295 microg/g for 4-VC. The highest level was found for 4-VC, which is a dimer of 1,3-BD, and the next highest was for AN, which is one of the monomers of the ABS copolymer. Furthermore, the method was also applied to acrylonitrile-styrene (AS) copolymers and polystyrenes (PS) for kitchen utensils, and nitrile-butadiene rubber (NBR) gloves. In AS copolymers, AN and PN were detected at 16.8-54.5 and 0.8-6.9 microg/g, respectively. On the other hand, the levels in PS and NBR samples were all low.

  11. Screening-level risk assessment for styrene-acrylonitrile (SAN) trimer detected in soil and groundwater.

    Science.gov (United States)

    Kirman, C R; Gargas, M L; Collins, J J; Rowlands, J C

    2012-01-01

    A screening-level risk assessment was conducted for styrene-acrylonitrile (SAN) Trimer detected at the Reich Farm Superfund site in Toms River, NJ. Consistent with a screening-level approach, on-site and off-site exposure scenarios were evaluated using assumptions that are expected to overestimate actual exposures and hazards at the site. Environmental sampling data collected for soil and groundwater were used to estimate exposure point concentrations. Several exposure scenarios were evaluated to assess potential on-site and off-site exposures, using parameter values for exposures to soil (oral, inhalation of particulates, and dermal contact) and groundwater (oral, dermal contact) to reflect central tendency exposure (CTE) and reasonable maximum exposure (RME) conditions. Three reference dose (RfD) values were derived for SAN Trimer for short-term, subchronic, and chronic exposures, based upon its effects on the liver in exposed rats. Benchmark (BMD) methods were used to assess the relationship between exposure and response, and to characterize appropriate points of departure (POD) for each RfD. An uncertainty factor of 300 was applied to each POD to yield RfD values of 0.1, 0.04, and 0.03 mg/kg-d for short-term, subchronic, and chronic exposures, respectively. Because a chronic cancer bioassay for SAN Trimer in rats (NTP 2011a) does not provide evidence of carcinogenicity, a cancer risk assessment is not appropriate for this chemical. Potential health hazards to human health were assessed using a hazard index (HI) approach, which considers the ratio of exposure dose (i.e., average daily dose, mg/kg-d) to toxicity dose (RfD, mg/kg-d) for each scenario. All CTE and RME HI values are well below 1 (where the average daily dose is equivalent to the RfD), indicating that there is no concern for potential noncancer effects in exposed populations even under the conservative assumptions of this screening-level assessment.

  12. Microporous poly(acrylonitrile-methyl methacrylate) membrane as a separator of rechargeable lithium battery

    International Nuclear Information System (INIS)

    Zhang, S.S.; Ervin, M.H.; Xu, K.; Jow, T.R.

    2004-01-01

    We studied microporous poly(acrylonitrile-methyl methacrylate), AMMA, membrane as the separator of Li/LiMn 2 O 4 cell. The porous AMMA membrane was prepared by the phase inversion method with N,N-dimethylformamide (DMF) as the solvent and water as the non-solvent. We observed that morphology of the resulting membrane was strongly affected by the concentration of polymer solution: low concentration produced finger-like pores with dense skin on two surfaces of the membrane, while high concentration yielded open voids with dense layer on the other surface of the membrane. Regardless of their morphology, both membranes could be rapidly wetted by the liquid electrolyte (1.0 m LiBF 4 dissolved in 1:3 wt.% mixture of ethylene carbonate (EC) and γ-butyrolactone (GBL)), and could be swollen at elevated temperatures, which resulted in the formation of a microporous gel electrolyte (MGE). It was shown that the resulting MGE not only had high ionic conductivity and but also had good compatibility with metal lithium even at 60 deg. C. Cyclic voltammetric test showed that the MGE had an electrochemical window of 4.9 V versus Li + /Li. At room temperature, the Li/MGE/LiMn 2 O 4 cell showed excellent cycliability with a specific capacity of 121-125 mA h g -1 LiMn 2 O 4 . It was shown that even at 60 deg. C good mechanical strength of the MGE remained. Therefore, the MGE is suitable for the application of battery separator at elevated temperatures

  13. Bonding properties of acrylonitrile butadiene rubber with polyamide mediated by a functional layer of silane coupling agent

    International Nuclear Information System (INIS)

    Sang, J.; Aisawa, S.; Hirahara, H.; Mori, K.

    2017-01-01

    This study demonstrates that coating layers, expected to be formed as self-assembled monolayers, of silane coupling agents can act as adhesion layers as the hydrogenated acrylonitrile butadiene rubber (HNBR) and polyamide (PA6) plate interfaces. The resulting PA6/HNBR joints showed excellent adhesion properties with cohesive failure and the interfaces were jointed through chemical bonds, which were confirmed by swelling tests. The surfaces and bonding properties of rubber and PA6 were studied by means of peel tests, X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and nanoscale infrared microscopy and chemical imaging (AFM-IR). (authors)

  14. Impact behavior of f-silica and amine terminated polybutadiene co-acrylonitrile rubber modified novolac epoxy/Kevlar nanocomposites

    Science.gov (United States)

    Kavita, Pal, Vijayeta; Tiwari, R. K.

    2018-05-01

    In the present work, nano-fumed silica treated with 3-Glycidoxypropyl trimethoxy silane (f-silica) was used as a nanoreinforcement in the fabrication of amine terminated polybutadiene co-acrylonitrile rubber (ATBN) modified Kevlar/epoxy based nanocomposites. Nanocomposites with different f-silica loading (0, 0.5, 1.0 and 2.0 wt. %) and having same ATBN (10 wt. %) were made and characterized by Izod impact test for evaluating impact strength values. All the nanocomposites showed better impact strength than neat Kevlar/novolac epoxy based composite.

  15. Synthesis of Novel Benzimidazolyl-substituted Acrylonitriles and Amidino-substituted Benzimidazo[1,2-a]Quinolines

    Directory of Open Access Journals (Sweden)

    Grace Karminski-Zamola

    2006-08-01

    Full Text Available A series of novel benzimidazole derivatives 3-10 were synthesized. Benzimidazolyl-substituted acrylonitriles 3 and 4 underwent a photochemical dehydrocyclization reaction to give the corresponding mono- and dicyano-substituted benzimidazo[1,2-a] quinolines 5 and 6. Pinner reaction of these compounds did not give the expected mono- and diamidines, but rather only compounds 7-10, with amido groups at 6-position were isolated. A mechanism for the reaction is proposed. Acyclic compounds 3 and 4, as well as cyclic benzimidazo[1,2-a]quinolines 5-8, exhibit interesting spectroscopic properties and are potential biologically active compounds.

  16. Study of the Influence of adding styrene-ethylene/butadiene-styrene in acrylonitrile-butadiene-styrene and polyethylene blends

    OpenAIRE

    Peydro, M. A.; Parres, F.; Navarro Vidal, Raúl; Sanchez-Caballero, Samuel

    2014-01-01

    This work studies the recovery of two grades of acrylonitrile butadiene styrene (ABS) contaminated with low-density polyethylene (LDPE), by adding styrene ethylene/butadiene styrene (SEBS). To simulate contaminated ABS, virgin ABS was mixed with 1, 2, 4, and 8% of LDPE and then extruded at 220°C. After this, the ABS with the highest percentage of LDPE (8%) was mixed with 1, 2, 4, and 8% of SEBS and then extruded. Different blends were mechanically, rheologically, optically, and dimensionally ...

  17. Quality inspection of anisotropic scintillating lead tungstate (PbWO 4) crystals through measurement of interferometric fringe pattern parameters

    Science.gov (United States)

    Cocozzella, N.; Lebeau, M.; Majni, G.; Paone, N.; Rinaldi, D.

    2001-08-01

    Scintillating crystals are widely used as detectors in radiographic systems, computerized axial tomography devices and in calorimeters employed in high-energy physics. This paper results from a project motivated by the development of the CMS calorimeter at CERN, which will make use of a large number of scintillating crystals. In order to prevent crystals from breaking because of internal residual stress, a quality control system based on optic inspection of interference fringe patterns was developed. The principle of measurement procedures was theoretically modelled, and then a dedicated polariscope was designed and built, in order to observe the crystals under induced stresses or to evaluate the residual internal stresses. The results are innovative and open a new perspective for scintillating crystals quality control: the photoelastic constant normal to the optic axis of the lead tungstate crystals (PbWO 4) was measured, and the inspection procedure developed is applicable to mass production, not only to optimize the crystal processing, but also to establish a quality inspection procedure.

  18. Decoration of nitrogen-doped reduced graphene oxide with cobalt tungstate nanoparticles for use in high-performance supercapacitors

    Science.gov (United States)

    Naderi, Hamid Reza; Sobhani-Nasab, Ali; Rahimi-Nasrabadi, Mehdi; Ganjali, Mohammad Reza

    2017-11-01

    A composite of cobalt tungstate nanoparticles coated on nitrogen-doped reduced graphene oxide (CoWO4/NRGO) was prepared through an in situ sonochemical approach. The composite was next evaluated as an electrode material for use supercapacitors electrodes. The characterization of the various CoWO4/NRGO nanocomposite samples was carried out through field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), X-ray photoemission spectroscopy (XPS), Brunauer-Emmett-Teller (BET) method and Raman spectroscopy. Complementary studies were also performed through cyclic voltammetry (CV), galvanostatic charge/discharge, electrochemical impedance spectroscopy (EIS), and continues cyclic voltammetry (CCV). The electrochemical evaluations were carried out in a 2 M H2SO4 solution as the electrolyte. The electrochemical evaluations on the nano-composite samples indicated that CoWO4/NRGO-based electrodes reveal enhanced supercapacitive characteristics (i.e. a high specific capacitance (SC) of 597 F g-1 at a scan rate of 5 mV s-1, an energy density (ED) value of 67.9 W h kg-1, and high rate capability). CCV studies indicated that CoWO4/NRGO-based electrodes keep 97.1% of their original capacitance after 4000 cycles. The results led to the conclusion that CoWO4/NRGO effectively merge the merits of CoWO4 and CoWO4/RGO in one new nanocomposite material.

  19. Quality inspection of anisotropic scintillating lead tungstate (PbWO4) crystals through measurement of interferometric fringe pattern parameters

    International Nuclear Information System (INIS)

    Cocozzella, N.; Lebeau, M.; Majni, G.; Paone, N.; Rinaldi, D.

    2001-01-01

    Scintillating crystals are widely used as detectors in radiographic systems, computerized axial tomography devices and in calorimeters employed in high-energy physics. This paper results from a project motivated by the development of the CMS calorimeter at CERN, which will make use of a large number of scintillating crystals. In order to prevent crystals from breaking because of internal residual stress, a quality control system based on optic inspection of interference fringe patterns was developed. The principle of measurement procedures was theoretically modelled, and then a dedicated polariscope was designed and built, in order to observe the crystals under induced stresses or to evaluate the residual internal stresses. The results are innovative and open a new perspective for scintillating crystals quality control: the photoelastic constant normal to the optic axis of the lead tungstate crystals (PbWO 4 ) was measured, and the inspection procedure developed is applicable to mass production, not only to optimize the crystal processing, but also to establish a quality inspection procedure

  20. Photoluminescence in solid solutions and thin films of tungstates CaWO{sub 4}-CdWO{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Taoufyq, A.; Mauroy, V.; Guinneton, F.; Valmalette, J-C. [University of Toulon, IM2NP, UMR CNRS 7334, La Garde, (France); Fiorido, T. [Aix Marseille University, IM2NP, UMR CNRS, 7334, Marseille, (France); Benlhachemi, A. [IBN ZOHR University, Faculty of sciences, Environment and Materials Laboratory, Agadir, (Morocco); Lyoussi, A. [CEA of Cadarache, DEN, Departement of reactors studies, experimental physics, Instrumentation Sensors and Dosimetry Laboratory, (France); Nolibe, G. [Cesigma society, signals and systems, La Garde, (France); Gavarri, J-R. [University of Toulon, IM2NP, UMR CNRS 7334, La Garde, (France)

    2015-07-01

    In this study, we present two types of studies on the luminescence properties under UV and X-ray excitations of solid solutions Ca{sub 1-x}Cd{sub x}WO{sub 4} and of thin layers of CaWO{sub 4} and CdWO{sub 4}. These tungstate based solid solutions are susceptible to be integrated into new radiation sensors, in order to be used in different fields of applications such as reactor measurements, safeguards, homeland security, nuclear nondestructive assays, LINAC emission radiation measurement. However these complex materials were rarely investigated in the literature. One first objective of our studies was to establish correlations between luminescence efficiency, chemical substitution and the degree of crystallization resulting from elaboration conditions. A second objective will be to determine the efficiency of luminescence properties of thin layers of these materials. In the present work, we focus our attention on the role of chemical substitution on photon emissions under UV and X-ray irradiations. The luminescence spectra of Ca{sub 1-x}Cd{sub x}WO{sub 4} polycrystalline materials have been investigated at room temperature as a function of composition (0≤x≤1). In addition, we present a preliminary study of the luminescence of CaWO{sub 4} and CdWO{sub 4} thin layers: oscillations observed in the case of X-ray excitations in the luminescence spectra are discussed. (authors)

  1. Enhanced structural and optical properties of the polyaniline-calcium tungstate (PANI-CaWO4 nanocomposite for electronics applications

    Science.gov (United States)

    Sabu, N. Aloysius; Francis, Xavier; Anjaly, Jose; Sankararaman, S.; Varghese, Thomas

    2017-06-01

    In this article, we report the synthesis and characterization of polyaniline-calcium tungstate nanocomposite, a novel material for potential applications. The PANI-CaWO4 nanocomposite was prepared by in situ oxidative polymerization of aniline in the presence of CaWO4 nanoparticles dispersed in ethanol. Investigations using X-ray diffraction, Fourier-transformed infrared spectroscopy, UV-visible, photoluminescence and Raman spectroscopy confirmed the formation of the nanocomposite of PANI with CaWO4 nanoparticles. Scanning electron microscopy revealed almost uniform distribution of CaWO4 nanoparticles in the polyaniline matrix. These studies also confirmed electronic structure modification as a result of incorporating CaWO4 nanoparticles in PANI. Composite formation resulted in large decrease in the optical band gap and enhanced photoluminescence. The augmented structural, optical and photoluminescence properties of the PANI-CaWO4 nanocomposite can be used to explore potential applications in micro- and optoelectronics. This is the first report presenting synthesis and characterization of the PANI-CaWO4 nanocomposite.

  2. Structural study of thin films prepared from tungstate glass matrix by Raman and X-ray absorption spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Montanari, Bianca; Barbosa, Anne J.; Ribeiro, Sidney J.L.; Messaddeq, Younes [Departamento de Quimica Geral e Inorganica, Instituto de Quimica, UNESP, CP 355, CEP 14800-900 Araraquara, SP (Brazil); Poirier, Gael [Departamento de Ciencias Exatas, UNIFAL-MG, CEP 37130-000 Alfenas, MG (Brazil)], E-mail: gael@unifal-mg.edu.br; Li, Maximo S. [Instituto de Fisica, USP, CP 369, CEP 13560-970 Sao Carlos, SP (Brazil)

    2008-06-30

    Thin films were prepared using glass precursors obtained in the ternary system NaPO{sub 3}-BaF{sub 2}-WO{sub 3} and the binary system NaPO{sub 3}-WO{sub 3} with high concentrations of WO{sub 3} (above 40% molar). Vitreous samples have been used as a target to prepare thin films. Such films were deposited using the electron beam evaporation method onto soda-lime glass substrates. Several structural characterizations were performed by Raman spectroscopy and X-ray Absorption Near Edge Spectroscopy (XANES) at the tungsten L{sub I} and L{sub III} absorption edges. XANES investigations showed that tungsten atoms are only sixfold coordinated (octahedral WO{sub 6}) and that these films are free of tungstate tetrahedral units (WO{sub 4}). In addition, Raman spectroscopy allowed identifying a break in the linear phosphate chains as the amount of WO{sub 3} increases and the formation of P-O-W bonds in the films network indicating the intermediary behavior of WO{sub 6} octahedra in the film network. Based on XANES data, we suggested a new attribution of several Raman absorption bands which allowed identifying the presence of W-O{sup -} and W=O terminal bonds and a progressive apparition of W-O-W bridging bonds for the most WO{sub 3} concentrated samples (above 40% molar) attributed to the formation of WO{sub 6} clusters.

  3. Fire and Gas Barrier Properties of Poly(styrene-co-acrylonitrile Nanocomposites Using Polycaprolactone/Clay Nanohybrid Based-Masterbatch

    Directory of Open Access Journals (Sweden)

    S. Benali

    2008-01-01

    Full Text Available Exfoliated nanocomposites are prepared by dispersion of poly(ε-caprolactone (PCL grafted montmorillonite nanohybrids used as masterbatches in poly(styrene-co-acrylonitrile (SAN. The PCL-grafted clay nanohybrids with high inorganic content are synthesized by in situ intercalative ring-opening polymerization of ε-caprolactone between silicate layers organomodified by alkylammonium cations bearing two hydroxyl functions. The polymerization is initiated by tin alcoholate species derived from the exchange reaction of tin(II bis(2-ethylhexanoate with the hydroxyl groups borne by the ammonium cations that organomodified the clay. These highly filled PCL nanocomposites (25 wt% in inorganics are dispersed as masterbatches in commercial poly(styrene-co-acrylonitrile by melt blending. SAN-based nanocomposites containing 3 wt% of inorganics are accordingly prepared. The direct blend of SAN/organomodified clay is also prepared for sake of comparison. The clay dispersion is characterized by wide-angle X-ray diffraction (WAXD, atomic force microscopy (AFM, and solid state NMR spectroscopy measurements. The thermal properties are studied by thermogravimetric analysis. The flame retardancy and gas barrier resistance properties of nanocomposites are discussed both as a function of the clay dispersion and of the matrix/clay interaction.

  4. Fabrication of Acrylonitrile-Butadiene-Styrene Nanostructures with Anodic Alumina Oxide Templates, Characterization and Biofilm Development Test for Staphylococcus epidermidis.

    Directory of Open Access Journals (Sweden)

    Camille Desrousseaux

    Full Text Available Medical devices can be contaminated by microbial biofilm which causes nosocomial infections. One of the strategies for the prevention of such microbial adhesion is to modify the biomaterials by creating micro or nanofeatures on their surface. This study aimed (1 to nanostructure acrylonitrile-butadiene-styrene (ABS, a polymer composing connectors in perfusion devices, using Anodic Alumina Oxide templates, and to control the reproducibility of this process; (2 to characterize the physico-chemical properties of the nanostructured surfaces such as wettability using captive-bubble contact angle measurement technique; (3 to test the impact of nanostructures on Staphylococcus epidermidis biofilm development. Fabrication of Anodic Alumina Oxide molds was realized by double anodization in oxalic acid. This process was reproducible. The obtained molds present hexagonally arranged 50 nm diameter pores, with a 100 nm interpore distance and a length of 100 nm. Acrylonitrile-butadiene-styrene nanostructures were successfully prepared using a polymer solution and two melt wetting methods. For all methods, the nanopicots were obtained but inside each sample their length was different. One method was selected essentially for industrial purposes and for better reproducibility results. The flat ABS surface presents a slightly hydrophilic character, which remains roughly unchanged after nanostructuration, the increasing apparent wettability observed in that case being explained by roughness effects. Also, the nanostructuration of the polymer surface does not induce any significant effect on Staphylococcus epidermidis adhesion.

  5. Kinetic studies of uranyl ion adsorption on acrylonitrile (AN)/polyethylene glycol (PEG) interpenetrating networks (IPN)

    International Nuclear Information System (INIS)

    Aycik, G.A.; Gurellier, R.

    2004-01-01

    Full text: The kinetics of the adsorption of uranyl ions on amidoximated acrylonitrile (AN)/ polyethylene glycol (PEG) interpenetrating network (IPNs) from aqueous solutions was studied as a function of time and temperature. The IPNs were prepared by irradiation initiated gamma polymerisation using Co-60 gamma source. Adsorption capacities were performed for definite uranyl ion concentrations of 1x10 -2 M and at four different temperatures as 290K, 298K, 308K and 318K by gamma spectrometer. Adsorption time was increased from zero to 48 hours. The results indicate that adsorption capacity increases linearly with increasing temperature. Temperature and agitation hardly influence equilibrium and kinetics and decreasing of temperature results in a slightly greater time to reach equilibrium. The adsorption of uranyl ions has been studied in a multi step mechanism processes thus comparing chemical sorption and diffusion sorption processes. The experimental data was analysed using various kinetic models to determine the best-fit equation for the adsorption mechanisms. However, it was shown that all models, in general according to the reaction time and uranyl ion concentration in the solution, could describe the adsorption of uranyl ion onto amidoximated IPN, the adsorption kinetics was best described by zeroth order and intraparticle diffusion model whereas that of in increasing time by pseudo first and pseudo second order response respectively. External-intraparticle diffusion and zeroth order process in the IPN structure is proposed as a mass transfer mechanism and the results indicate a diffusion-controlled process. The Mean Activation Energy Of Uranyl Ions Adsorption Was Found As 4,1 Kj/Mole By Using Arrhenius Equation. The Rate Constant, The Equilibrium Adsorption Capacity And The Initial Adsorption Rate Were Calculated For All Models At Each Temperature. Kinetic Parameters Of All Models And The Normalized Standard Deviations Between The Measured And Predicted

  6. Acrylonitrile potentiates hearing loss and cochlear damage induced by moderate noise exposure in rats

    International Nuclear Information System (INIS)

    Pouyatos, BenoIt; Gearhart, Caroline A.; Fechter, Laurence D.

    2005-01-01

    The diversity of chemical and drugs that can potentiate noise-induced hearing loss (NIHL) has impeded efforts to predict such interactions. We have hypothesized that chemical contaminants that disrupt intrinsic antioxidant defenses hold significant risk for potentiating NIHL. If this is true, then acrylonitrile (ACN) would be expected to potentiate NIHL. ACN, one of the 50 most commonly used chemicals in the United States, is metabolized via two pathways that are likely to disrupt intrinsic reactive oxygen species (ROS) buffering systems: (1) it conjugates glutathione, depleting this important antioxidant rapidly; (2) a second pathway involves the formation of cyanide, which can inhibit superoxide dismutase. We hypothesized that moderate noise exposure, that does not produce permanent hearing loss by itself, could initiate oxidative stress and that ACN could render the inner ear more sensitive to noise by disrupting intrinsic antioxidant defenses. Temporary and persistent effects of ACN alone (50 mg/kg, sc 5 days), noise alone (95 or 97 dB octave band noise, 4 h/day for 5 days), or ACN in combination with noise were determined using distortion product otoacoustic emissions (DPOAEs) and compound action potential (CAP) amplitudes. Histopathological damage to hair cells resulting from these treatments was also investigated using surface preparations of the organ of Corti. Individually, neither ACN nor noise exposures caused any permanent hearing or hair cell loss; only a reversible temporary threshold shift was measured in noise-exposed animals. However, when given in combination, ACN and noise induced permanent threshold shifts (13-16 dB between 7 and 40 kHz) and a decrease in DPOAE amplitudes (up to 25 dB at 19 kHz), as well as significant outer hair cell (OHC) loss (up to 20% in the first row between 13 and 47 kHz). This investigation demonstrates that ACN can potentiate NIHL at noise levels that are realistic in terms of human exposure, and that the OHCs are the

  7. Screening-Level Risk Assessment for Styrene-Acrylonitrile (SAN) Trimer Detected in Soil and Groundwater

    Science.gov (United States)

    Kirman, C. R.; Gargas, M. L.; Collins, J. J.; Rowlands, J. C.

    2012-01-01

    A screening-level risk assessment was conducted for styrene-acrylonitrile (SAN) Trimer detected at the Reich Farm Superfund site in Toms River, NJ. Consistent with a screening-level approach, on-site and off-site exposure scenarios were evaluated using assumptions that are expected to overestimate actual exposures and hazards at the site. Environmental sampling data collected for soil and groundwater were used to estimate exposure point concentrations. Several exposure scenarios were evaluated to assess potential on-site and off-site exposures, using parameter values for exposures to soil (oral, inhalation of particulates, and dermal contact) and groundwater (oral, dermal contact) to reflect central tendency exposure (CTE) and reasonable maximum exposure (RME) conditions. Three reference dose (RfD) values were derived for SAN Trimer for short-term, subchronic, and chronic exposures, based upon its effects on the liver in exposed rats. Benchmark (BMD) methods were used to assess the relationship between exposure and response, and to characterize appropriate points of departure (POD) for each RfD. An uncertainty factor of 300 was applied to each POD to yield RfD values of 0.1, 0.04, and 0.03 mg/kg-d for short-term, subchronic, and chronic exposures, respectively. Because a chronic cancer bioassay for SAN Trimer in rats (NTP 2011a) does not provide evidence of carcinogenicity, a cancer risk assessment is not appropriate for this chemical. Potential health hazards to human health were assessed using a hazard index (HI) approach, which considers the ratio of exposure dose (i.e., average daily dose, mg/kg-d) to toxicity dose (RfD, mg/kg-d) for each scenario. All CTE and RME HI values are well below 1 (where the average daily dose is equivalent to the RfD), indicating that there is no concern for potential noncancer effects in exposed populations even under the conservative assumptions of this screening-level assessment. PMID:23030654

  8. The potential reproductive, neurobehavioral and systemic effects of soluble sodium tungstate exposure in Sprague-Dawley rats

    International Nuclear Information System (INIS)

    McInturf, S.M.; Bekkedal, M.Y.V.; Wilfong, E.; Arfsten, D.; Chapman, G.; Gunasekar, P.G.

    2011-01-01

    The debate on tungsten (W) is fostered by its continuous usage in military munitions. Reports demonstrate W solubilizes in soil and can migrate into drinking water supplies and, therefore, is a potential health risk to humans. This study evaluated the reproductive, systemic and neurobehavioral effects of sodium tungstate (NaW) in rats following 70 days of daily pre-and postnatal exposure via oral gavage to 5, 62.5 and 125 mg/kg/day of NaW through mating, gestation and weaning (PND 0-20). Daily administration of NaW produced no overt evidence of toxicity and had no apparent effect on mating success or offspring physical development. Distress vocalizations were elevated in F 1 offspring from the high dose group, whereas righting reflex showed unexpected sex differences where males demonstrated faster righting than females; however, the effects were not dose-dependent. Locomotor activity was affected in both low and high-dose groups of F 1 females. Low-dose group showed increased distance traveled, more time in ambulatory movements and less time in stereotypic behavior than controls or high dose animals. The high-dose group had more time in stereotypical movements than controls, and less time resting than controls and the lowest exposure group. Maternal retrieval was not affected by NaW exposure. Tungsten analysis showed a systemic distribution of NaW in both parents and offspring, with preferential uptake within the immune organs, including the femur, spleen and thymus. Histopathological evidence suggested no severe chronic injury or loss of function in these organs. However, the heart showed histological lesions, histiocytic inflammation from minimal to mild with cardiomyocyte degeneration and necrosis in several P 0 animals of 125 mg NaW dose group. The result of this study suggests that pre and postnatal exposure to NaW may produce subtle neurobehavioral effects in offspring related to motor activity and emotionality.

  9. On halide derivatives of rare-earth metal(III) oxidomolybdates(VI) and -tungstates(VI)

    International Nuclear Information System (INIS)

    Schleid, Thomas; Hartenbach, Ingo

    2016-01-01

    Halide derivatives of rare-earth metal(III) oxidomolybdates(VI) have been investigated comprehensively over the last decade comprising the halogens fluorine, chlorine, and bromine. Iodide-containing compounds are so far unknown. The simple composition REXMoO 4 (RE=rare-earth element, X=halogen) is realized for X=F almost throughout the complete lanthanide series as well as for yttrium. While ytterbium and lutetium do not form any fluoride derivative, for lanthanum, only a fluoride-deprived compound with the formula La 3 FMo 4 O 16 is realized. Moreover, molybdenum-rich compounds with the formula REXMo 2 O 7 are also known for yttrium and the smaller lanthanoids. For X=Cl the composition REClMoO 4 is known for yttrium and the whole lanthanide series, although, four different structure types were identified. Almost the same holds for X=Br, however, only two different structure types are realized in this class of compounds. In the case of halide derivatives of rare-earth metal(III) oxidotungstates(VI) the composition REXWO 4 is found for chlorides and bromides only, so far. Due to the similar size of Mo 6+ and W 6+ cations, the structures found for the tungstates are basically the same as for the molybdates. With the larger lanthanides, the representatives for both chloride and bromide derivates exhibit similar structural motifs as seen in the molybdates, however, the crystal structure cannot be determined reliably. In case of the smaller lanthanoids, the chloride derivatives are isostructural with the respective molybdates, although the existence ranges differ slightly. The same is true for rare-earth metal(III) bromide oxidotungstates(VI).

  10. Proposal for the award of a contract for the supply of 26 000 lead-tungstate scintillation crystals for the CMS electromagnetic calorimeter

    CERN Document Server

    2001-01-01

    This document concerns the award of a contract for the supply of 26 000 lead-tungstate scintillation crystals for the barrel part of the CMS Electromagnetic Calorimeter (ECAL). Following a CERN market survey (MS-2727/EP/CMS) carried out among seven firms in four Member States and two firms in two non-Member States, the Eidgenössische Technische Hochschule in Z rich (ETHZ) published on 15 February 2001 an open call for tenders and, in addition, invited tenders from four firms in two non-Member States, including the two firms identified in the CERN market survey. By the closing date, the ETHZ had received one bid from a firm in a CERN Member State and three bids from three firms in two non-Member States. The Finance Committee is invited to agree to the negotiation of a contract to be placed by CERN, on behalf of the ETHZ, with the lowest bidder, SCIONIX (NL), for the supply of 26 000 lead-tungstate crystals for the barrel part of the CMS ECAL for a total amount of 9 392 000 US dollars (16 060 320 Swiss francs)...

  11. Enhancing both the mechanical and chemical properties of paper sheet by graft co-polymerization with acrylonitrile/methyl methacrylate

    Directory of Open Access Journals (Sweden)

    H.M. Abd El Salam

    2014-09-01

    Full Text Available The chemical graft copolymerization reaction of acrylonitrile (AN and methyl methacrylate (MMA binary mixture onto paper sheet was performed. The effect of initiator concentration, monomer concentration and temperature on the reaction rate was studied. The reaction rate equation of the graft copolymerization reaction is found to be RP = K2 [Initiator]0.795[Monomer]2.007. The apparent activation energy (Ea of the copolymerization reaction is found to be 75.01 kJ/mol. The infrared characteristic absorption bands for cellulosic paper structure and the paper gr-AN-MMA are investigated. Tensile break load, porosity and burst strength were measured for the grafted and pure paper sheet. It was found that the mechanical properties are improved by grafting copolymerization. The chemical resistance of the graft product against a strong acid a strong alkali, polar and nonpolar solvents was investigated. It was found that the resistance to these chemicals is enhanced by grafting.

  12. The use of poly(vinylpyridine-co-acrylonitrile) in polymer electrolytes for quasi-solid dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Li, Minyu; Feng, Shujing; Fang, Shibi; Xiao, Xurui; Li, Xueping; Zhou, Xiaowen; Lin, Yuan

    2007-01-01

    Poly(vinylpyridine-co-acrylonitrile) (P(VP-co-AN)) was used to form polymer electrolytes for dye-sensitized solar cells (DSSCs). The effects of P(VP-co-AN) on the photovoltaic performances of DSSCs have been investigated with nonaqueous electrolytes containing alkali-iodide and iodine. It was found that the effect of P(VP-co-AN) on V oc closely related to its amount in the electrolyte. Lower amount of P(VP-co-AN) was benefit for the construction of a solar cell containing P(VP-co-AN) with higher energy conversion efficiency. Chemically crosslinking solidification with backbone polymer P(VP-co-AN) amount of 3% fabricated quasi-solid DSSCs with 10% increased conversion efficiencies with relative to that of the initial liquid DSSCs

  13. Effect of concentration of polyfunctional monomers on physical properties of acrylonitrile-butadiene rubber under electron-beam irradiation

    International Nuclear Information System (INIS)

    Yasin, T.; Ahmed, S.; Yoshii, F.; Makuuchi, K.

    2003-01-01

    The effect of concentration of different polyfunctional monomers (PFMs) on the physical properties of electron-beam irradiated acrylonitrile-butadiene rubber (NBR) has been investigated. The PFMs used were diethylene glycol dimethacrylate (2G), tetraethylene glycol dimethacrylate (4G), trimethylol propane triacrylate (A-TMPT), trimethylol propane trimethacrylate (TMPT) and tetramethylol methane tetraacrylate (A-TMMT). The physical properties of EB irradiated NBR sheets were evaluated by measurement of tensile strength, elongation %, hardness and gel fraction etc. The results show a remarkable increase in all physical properties as the concentration of PFMs increases from 1 phr to 5 phr in the NBR samples. The improvement in physical properties of radiation crosslinked NBR in the presence of PFMs may be attributed to its increased crosslinking density as observed by corresponding increase in gel content

  14. Effect of concentration of polyfunctional monomers on physical properties of acrylonitrile butadiene rubber under electron-beam irradiation

    Science.gov (United States)

    Yasin, Tariq; Ahmed, Shamshad; Ahmed, Munir; Yoshii, Fumio

    2005-06-01

    An investigation has been undertaken to find out the effect of concentration of different polyfunctional monomers (PFMs) on the physical properties of the acrylonitrile-butadiene rubber (NBR) crosslinked by electron beam (EB). The PFMs used were diethylene glycol dimethacrylate, trimethylol propane trimethacrylate and trimethylol propane triacrylate. The physical properties of EB-irradiated NBR sheets were evaluated by measuring the tensile strength, elongation percent at break, hardness and gel fraction. The results showed a remarkable increase in tensile strength, hardness and gel fraction as the concentration of PFMs was increased from 1 part per hundred (phr) to 5 phr in the NBR samples whereas elongation percent decreased in a steady manner. The improvement in physical properties of radiation crosslinked NBR in the presence of PFMs may be attributed to its increased crosslinking density as observed by the corresponding increase in gel content.

  15. Effect of concentration of polyfunctional monomers on physical properties of acrylonitrile-butadiene rubber under electron-beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Yasin, Tariq [Polymer Processing and Radiation Technology Laboratory, Applied Chemistry Division, Pakistan Institute of Nuclear Science and Technology, P.O. Nilore, Islamabad (Pakistan)]. E-mail: yasintariq@yahoo.com; Ahmed, Shamshad [Polymer Processing and Radiation Technology Laboratory, Applied Chemistry Division, Pakistan Institute of Nuclear Science and Technology, P.O. Nilore, Islamabad (Pakistan); Ahmed, Munir [Polymer Processing and Radiation Technology Laboratory, Applied Chemistry Division, Pakistan Institute of Nuclear Science and Technology, P.O. Nilore, Islamabad (Pakistan); Yoshii, Fumio [Takasaki Radiation Chemistry Research Establishment, JAERI, Takasaki, Gunma-Ken 370-12 (Japan)

    2005-06-01

    An investigation has been undertaken to find out the effect of concentration of different polyfunctional monomers (PFMs) on the physical properties of the acrylonitrile-butadiene rubber (NBR) crosslinked by electron beam (EB). The PFMs used were diethylene glycol dimethacrylate, trimethylol propane trimethacrylate and trimethylol propane triacrylate. The physical properties of EB-irradiated NBR sheets were evaluated by measuring the tensile strength, elongation percent at break, hardness and gel fraction. The results showed a remarkable increase in tensile strength, hardness and gel fraction as the concentration of PFMs was increased from 1 part per hundred (phr) to 5 phr in the NBR samples whereas elongation percent decreased in a steady manner. The improvement in physical properties of radiation crosslinked NBR in the presence of PFMs may be attributed to its increased crosslinking density as observed by the corresponding increase in gel content.

  16. The Effect of Concentration of P-phenylenediamine Antioxidant on the Acrylonitrile-Butadiene Rubber Seals under High Gamma Irradiation

    International Nuclear Information System (INIS)

    Hegazi, E.M.; Abd El-megeed, A.A.

    2016-01-01

    Acrylonitrile- butadiene rubber (NBR) seals are one of the classified seals used in nuclear facilities. But at high irradiation doses the physical and mechanical properties of NBR are adversely affected due to the degradation induced by radiation and hence affect the sealing performance reducing their service life. The present work is focused on studying the effect of concentration of N-(1, 3-dimethylbutyl)-N’-phenyl-p-phenylene diamine (6PPD) on the physical and mechanical properties of the NBR rubber at high doses of γ-irradiation up to 2 MGy. The physical properties, mechanical properties, hardness, and abrasion of the NBR rubber under γ-radiation were investigated. The optimum amount of 6PPD required to resist deterioration is also estimated. The results showed a remarkable increase in the physical and mechanical properties as the concentration of 6PPD was increased from 1 phr (part per hundred) to 3 phr in NBR samples

  17. Effect of Silane Coupling Agent on the Creep Behavior and Mechanical Properties of Carbon Fibers/Acrylonitrile Butadiene Rubber Composites.

    Science.gov (United States)

    Choi, Woong-Ki; Park, Gil-Young; Kim, Byoung-Shuk; Seo, Min-Kang

    2018-09-01

    In this study, we investigated the effect of the silane coupling agent on the relationship between the surface free energy of carbon fibers (CFs) and the mechanical strength of CFs/acrylonitrile butadiene rubber (NBR) composites. Moreover, the creep behavior of the CF/NBR composites at surface energetic point of view were studied. The specific component of the surface free energy of the carbon fibers was found to increase upon grafting of the silane coupling agent, resulting in an increase in the tensile strength of the CF/NBR composites. On the other hand, the compressive creep strength was found to follow a slightly different trend. These results indicate the possible formation of a complex interpenetrating polymer network depending on the molecular size of the organic functional groups of the silane coupling agent.

  18. Effect of concentration of polyfunctional monomers on physical properties of acrylonitrile-butadiene rubber under electron-beam irradiation

    International Nuclear Information System (INIS)

    Yasin, Tariq; Ahmed, Shamshad; Ahmed, Munir; Yoshii, Fumio

    2005-01-01

    An investigation has been undertaken to find out the effect of concentration of different polyfunctional monomers (PFMs) on the physical properties of the acrylonitrile-butadiene rubber (NBR) crosslinked by electron beam (EB). The PFMs used were diethylene glycol dimethacrylate, trimethylol propane trimethacrylate and trimethylol propane triacrylate. The physical properties of EB-irradiated NBR sheets were evaluated by measuring the tensile strength, elongation percent at break, hardness and gel fraction. The results showed a remarkable increase in tensile strength, hardness and gel fraction as the concentration of PFMs was increased from 1 part per hundred (phr) to 5 phr in the NBR samples whereas elongation percent decreased in a steady manner. The improvement in physical properties of radiation crosslinked NBR in the presence of PFMs may be attributed to its increased crosslinking density as observed by the corresponding increase in gel content

  19. Hardness and swelling behaviour of epoxidized natural rubber/recycled acrylonitrile-butadiene rubber (ENR 50/NBRr) blends

    Science.gov (United States)

    Ahmad, Hazwani Syaza; Ismail, Hanafi; Rashid, Azura A.

    2017-07-01

    This recent work is to investigate the hardness and swelling behaviour of epoxidized natural rubber/recycled acrylonitrile-butadiene rubber (ENR 50/NBRr) blends. ENR 50/NBRr blends were prepared by two-roll mills with five different loading of NBRr from 5 to 35 phr. Results indicated that the hardness of ENR 50/NBRr blends increased as recycled NBR increased due to the improvement in crosslink density of the blends. Increasing NBRr content gives ENR 50/NBRr blends better resistance towards swelling. Higher degree of crosslinking will increase the swelling resistance and reduce the penetration of toluene into the blends. The presence of polar group in ENR 50 and NBRr give better hardness properties and swelling behaviour of the ENR 50/NBRr blends compared to the NR/NBRr blends.

  20. Effect of Graphene Oxide Mixed Epoxy on Mechanical Properties of Carbon Fiber/Acrylonitrile-Butadiene-Styrene Composites.

    Science.gov (United States)

    Wang, Cuicui; Ge, Heyi; Ma, Xiaolong; Liu, Zhifang; Wang, Ting; Zhang, Jingyi

    2018-04-01

    In this study, the watersoluble epoxy resin was prepared via the ring-opening reaction between diethanolamine and epoxy resin. The modified resin mixed with graphene oxide (GO) as a sizing agent was coated onto carbon fiber (CF) and then the GO-CF reinforced acrylonitrile-butadienestyrene (ABS) composites were prepared. The influences of the different contents of GO on CF and CF/ABS composite were explored. The combination among epoxy, GO sheets and maleic anhydride grafted ABS (ABSMA) showed a synergistic effect on improving the properties of GO-CF and GO-CF/ABS composite. The GO-CF had higher single tensile strength than the commercial CF. The maximum ILSS of GO-CF/ABS composite obtained 19.2% improvement as compared with that of the commercial CF/ABS composite. Such multiscale enhancement method and the synergistic reinforced GO-CF/ABS composite show good prospective applications in many industry areas.

  1. UV shielding with visible transparency based properties of poly (styrene-co-acrylonitrile)/Ag doped ZnO nanocomposite

    Science.gov (United States)

    Singh, Rajender; Verma, Karan; Singh, Tejbir; Barman, P. B.; Sharma, Dheeraj

    2018-02-01

    Development of ultraviolet (UV) shielding with visible transparency based thermoplastic polymer nanocomposite (PNs) presents an important requisite in terms of their efficiency and cost. Present study contributed for the same approach by dispersion of Ag doped ZnO nanoparticles upto 10 wt% in poly (styrene-co-acrylonitrile) matrix by insitu emulsion polymerization method. The crystal and chemical structure of PNs has been analyzed by x-ray diffraction (XRD) and fourier infrared spectrometer (FTIR) techniques. The morphological and elemental information of synthesized nanomaterial has been studied by field emission scanning electron microscope (FESEM) and energy dispersive spectroscopy (EDS) technique. The optical properties of PNs has been studied by UV-visible spectroscopy technique. The incorporation of nanoparticles in polymer matrix absorb the complete UV light with visible transparency. The present reported polymer nanocomposite (PNs) have tuned refractive index with UV blocking and visible transparency based properties which can serve as a viable alternative as compared to related conventional materials.

  2. Nature of hydrocarbon activation in oxidative ammonolysis of propane to acrylonitrile over a gallium-antimony oxide catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Osipova, Z.G.; Sokolovskii, V.D.

    1979-03-01

    The nature of hydrocarbon activation in oxidative ammonolysis of propane to acrylonitrile over a gallium-antimony oxide catalyst GaSbNiPOx (1:3:1.5:1 atomic ratios of the elements) was studied by comparing the rate of this reaction at 550/sup 0/C and 5Vertical Bar3< by vol propane/6Vertical Bar3< ammonia/18.6Vertical Bar3< oxygen/70.4Vertical Bar3< helium reactant mixture with that of isobutane ammoxidation to methacrylonitrile under the same conditions, at low (Vertical Bar3; 20Vertical Bar3<) conversions that prevent secondary oxidation of the products. Both the over-all hydrocarbon conversion rate and that of nitrile formation were higher for propane, suggesting that the reactions proceed via the respective carbanions (probably primary carbanions), rather than carbocations or uncharged radicals.

  3. Superhydrophilic poly (styrene co acrylonitrile)-ZnO nanocomposite surfaces for UV shielding and self-cleaning applications

    Science.gov (United States)

    Singh, Rajender; Sharma, Ramesh; Barman, P. B.; Sharma, Dheeraj

    2017-11-01

    UV shielding based super hydrophilic material is developed in the present formulation by in situ emulsion polymerization of poly (styrene-acrylonitrile) with ZnO nanoparticles. The ESI-MS technique confirms the structure of polymer nanocomposite by their mass fragments. The XRD study confirms the presence of ZnO phase in polymer matrix. PSAN/ZnO nanocomposite leads to give effective UV shielding (upto 375 nm) and visible luminescence with ZnO content in polymer matrix. The FESEM and TEM studies confirm the symmetrical, controlled growth of PNs. The incorporation of ZnO nanofillers into PSAN matrix lead to restructuring the PNs surfaces into superhydrophilic surfaces in water contact angle (WCA) from 70° to 10°. We believe our synthesized PSAN/ZnO nanocomposite could be potential as UV shielding, luminescent and super hydrophilic nature based materials in related commercial applications.

  4. Photodissociation of acrylonitrile at 193 nm: A photofragment translational spectroscopy study using synchrotron radiation for product photoionization

    International Nuclear Information System (INIS)

    Blank, D.A.; Suits, A.G.; Lee, Y.T.; North, S.W.; Hall, G.E.

    1998-01-01

    We have investigated the photodissociation of acrylonitrile (H 2 CCHCN) at 193 nm using the technique of photofragment translational spectroscopy. The experiments were performed at the Chemical Dynamics Beamline at the Advanced Light Source and used tunable vacuum ultraviolet synchrotron radiation for product photoionization. We have identified four primary dissociation channels including atomic and molecular hydrogen elimination, HCN elimination, and CN elimination. There is significant evidence that all of the dissociation channels occur on the ground electronic surface following internal conversion from the initially optically prepared state. The product translational energy distributions reflect near statistical simple bond rupture for the radical dissociation channels, while substantial recombination barriers mediate the translational energy release for the two molecular elimination channels. Photoionization onsets have provided additional insight into the chemical identities of the products and their internal energy content. copyright 1998 American Institute of Physics

  5. Environmentally benign electroless nickel plating using supercritical carbon-dioxide on hydrophilically modified acrylonitrile-butadiene-styrene

    Science.gov (United States)

    Tengsuwan, Siwach; Ohshima, Masahiro

    2014-08-01

    Electroless Ni-P plating using supercritical carbon dioxide (scCO2) in conjunction with copolymer-based hydrophilic modification was applied to an acrylonitrile-butadiene-styrene (ABS) substrate. The surface of ABS substrate was hydrophilically modified by blending with a multi-block copolymer, poly(ether-ester-amide)s (PEEA), in injection molding process. The substrate was then impregnated with Pd(II)-hexafluoroacetylacetonate, Pd(hfa)2, using scCO2, followed by the electroless plating reaction. ABS/PEEA substrates with different PEEA to ABS blend ratios and different volume ratios of butadiene to the styrene-acrylonitrile copolymer (SAN) matrix were prepared to investigate how the dispersed PEEA and butadiene domains affected the blend morphology and the adhesive strength of the plating metal-to-polymer contact. Increasing the PEEA copolymer to ABS blend ratio increased the mass transfer rate of the plating solution in the ABS substrate. Consequently, the metal-polymer composite layer became thicker, which increased the adhesive strength of the metal-to-polymer contact because of the anchoring effect. The butadiene domains appeared to attract the Pd catalyst precursor, and thus, the proportion of butadiene in the ABS matrix also affected the adhesive strength of the contact between the metal layer and the substrate. The ABS substrate was successfully plated with a Ni-P metal layer with an average adhesive strength of 9.1 ± 0.5 N cm-1 by choosing appropriate ABS/PEEA blend ratios and a Pd(hfa)2 concentration.

  6. Study on Exothermic Oxidation of Acrylonitrile-butadiene-styrene (ABS Resin Powder with Application to ABS Processing Safety

    Directory of Open Access Journals (Sweden)

    Jenq-Renn Chen

    2010-08-01

    Full Text Available Oxidative degradation of commercial grade ABS (Acrylonitrile-butadiene-styrene resin powders was studied by thermal analysis. The instabilities of ABS containing different polybutadiene (PB contents with respect to temperature were studied by Differential Scanning Calorimeter (DSC. Thermograms of isothermal test and dynamic scanning were performed. Three exothermic peaks were observed and related to auto-oxidation, degradation and oxidative decomposition, respectively. Onset temperature of the auto-oxidation was determined to be around 193 °C. However, threshold temperature of oxidation was found to be as low as 140 °C by DSC isothermal testing. Another scan of the powder after degeneration in air showed an onset temperature of 127 °C. Reactive hazards of ABS powders were verified to be the exothermic oxidation of unsaturated PB domains, not the SAN (poly(styrene-acrylonitrile matrix. Heat of oxidation was first determined to be 2,800 ± 40 J per gram of ABS or 4,720 ± 20 J per gram of PB. Thermal hazards of processing ABS powder are assessed by adiabatic temperature rise at process conditions. IR spectroscopy associated with heat of oxidation verified the oxidative mechanism, and these evidences excluded the heat source from the degradation of SAN. A specially prepared powder of ABS without adding anti-oxidant was analyzed by DSC for comparing the exothermic behaviors. Exothermic onset temperatures were determined to be 120 °C and 80 °C by dynamic scanning and isothermal test, respectively. The assessment successfully explained fires and explosions in an ABS powder dryer and an ABS extruder.

  7. Genotoxicity of Styrene–Acrylonitrile Trimer in Brain, Liver, and Blood Cells of Weanling F344 Rats

    Science.gov (United States)

    Hobbs, Cheryl A.; Chhabra, Rajendra S.; Recio, Leslie; Streicker, Michael; Witt, Kristine L.

    2012-01-01

    Styrene–acrylonitrile Trimer (SAN Trimer), a by-product in production of acrylonitrile styrene plastics, was identified at a Superfund site in Dover Township, NJ, where childhood cancer incidence rates were elevated for a period of several years. SAN Trimer was therefore tested by the National Toxicology Program in a 2-year perinatal carcinogenicity study in F344/N rats and a bacterial mutagenicity assay; both studies gave negative results. To further characterize its genotoxicity, SAN Trimer was subsequently evaluated in a combined micronucleus (MN)/Comet assay in juvenile male and female F344 rats. SAN Trimer (37.5, 75, 150, or 300 mg/kg/day) was administered by gavage once daily for 4 days. Micronucleated reticulocyte (MN-RET) frequencies in blood were determined by flow cytometry, and DNA damage in blood, liver, and brain cells was assessed using the Comet assay. Highly significant dose-related increases (P < 0.0001) in MN-RET were measured in both male and female rats administered SAN Trimer. The RET population was reduced in high dose male rats, suggesting chemical-related bone marrow toxicity. Results of the Comet assay showed significant, dose-related increases in DNA damage in brain cells of male (P < 0.0074) and female (P < 0.0001) rats; increased levels of DNA damage were also measured in liver cells and leukocytes of treated rats. Chemical-related cytotoxicity was not indicated in any of the tissues examined for DNA damage. The results of this subacute MN/Comet assay indicate induction of significant genetic damage in multiple tissues of weanling F344 male and female rats after oral exposure to SAN Trimer. PMID:22351108

  8. Fittings of unplasticized polyvinyl chloride (PVC-U), chlorinated polyvinyl chloride (PVC-C) or acrylonitrile/butadiene/styrene (ABS) with plain sockets for pipes under pressure - Dimensions of sockets - Metric series

    CERN Document Server

    International Organization for Standardization. Geneva

    1985-01-01

    Fittings of unplasticized polyvinyl chloride (PVC-U), chlorinated polyvinyl chloride (PVC-C) or acrylonitrile/butadiene/styrene (ABS) with plain sockets for pipes under pressure - Dimensions of sockets - Metric series

  9. Plastics piping systems for industrial applications – Acrylonitrile-butadiene-styrene (ABS), unplasticized poly(vinyl chloride) (PVC-U) and chlorinated poly(vinyl chloride) (PVC-C) – Specifications for components and the system – Metric series

    CERN Document Server

    Deutsches Institut für Normung. Berlin

    2003-01-01

    Plastics piping systems for industrial applications – Acrylonitrile-butadiene-styrene (ABS), unplasticized poly(vinyl chloride) (PVC-U) and chlorinated poly(vinyl chloride) (PVC-C) – Specifications for components and the system – Metric series

  10. Plastics piping systems for industrial applications : acrylonitrile-butadiene- styrene (ABS), unplasticized poly(vinyl chloride) (PVC-U) and chlorinated poly(vinyl chloride) (PVC-C) : specifications for components and the system : metric series

    CERN Document Server

    International Organization for Standardization. Geneva

    2003-01-01

    Plastics piping systems for industrial applications : acrylonitrile-butadiene- styrene (ABS), unplasticized poly(vinyl chloride) (PVC-U) and chlorinated poly(vinyl chloride) (PVC-C) : specifications for components and the system : metric series

  11. Development of proton conducting materials and membranes based on lanthanum tungstate for hydrogen separation from gas mixtures

    International Nuclear Information System (INIS)

    Seeger, Janka

    2013-01-01

    Lanthanum tungstate La 6-x WO 12-δ (named LWO) is a ceramic material with mixed protonic electronic conductivity. Thereby it is a good candidate membrane material for hydrogen separation from synthesis gas in a fossil pre-combustion power plant. This work shows a material optimization by substitution targeted to clearly enhance the mixed conductivity and thereby the hydrogen flow through the LWO membrane. The first part of the work shows the synthesis and characterization of unsubstituted LWO. It points out that monophase LWO powder can be reproducibly synthesized. The La/W-ratio has to be considerably smaller than the nominal ratio of La/W = 6.0. It also depends on the used sintering conditions. Different relevant properties of LWO like stability in conditions close to application, thermal expansion, sintering behavior or microstructure were determined. Furthermore, the electrical conductivity of the material was investigated. LWO exhibits a prevailing protonic conductivity up to 750 C in wet atmospheres. Under dry atmospheres n-type conductivity was dominating. Oxygen ion and n-type conductivity dominated in wet and dry atmospheres above 750 C. The main part of the work is concerned with the development of new LWO based materials by substitutions. The aim is to achieve an improved mixed protonic electronic conductivity. Substitution elements for lanthanum side were Mg, Ca, Sr, Ba, Ce, Nd, Tb, Y and Al, while for the tungsten side Mo, Re and Ir were used. The total conductivity of the developed materials was investigated and compared to that of the unsubstituted LWO. The substitution of lanthanum led to no appreciable enhancement of the conductivity whereas the substitution of tungsten with 20 mol% molybdenum or 20 mol% rhenium clearly improved it. This caused a hydrogen flow about seven times higher for 20 mol% molybdenum- and about ten times higher for 20 mol% rhenium-substituted LWO in comparison with the unsubstituted LWO at 700 C. In the last part of the

  12. Nitrate ({sup 13}NO{sub 3}{sup -}) flux studies and response to tungstate treatments in wild type barley and in an NR-deficient mutant

    Energy Technology Data Exchange (ETDEWEB)

    Wieneke, J.

    1994-07-01

    Hydroponic experiments were conducted with seedlings of barley (Hordeum vulgare L.), comparing the wild type and an NR-deficient mutant (AZ 12/70), to monitor the NO{sub 3}{sup -} influx/efflux relations and the response to tungstate treatment using {sup 13}N-labelling. Upon treatment with the arginyl-residue-binding inhibitor phenylglyoxal both genotypes responded with an immediate depression of NO{sub 3}{sup -} influx. At low external NO{sub 3}{sup -} concentrations efflux was small (5-15% of the influx) and did not differ substantially between the two genotypes. Although the mutant was distinguished from the wild type by a thinner root system and a reduced shoot length, the total N distribution between roots and shoots and the N concentrations in the root and shoot tissues were fairly comparable. Substantially higher extractable NO{sub 3}{sup -} concentration in the shoots (but not roots) of the mutant may indicate that the capacity to reduce NO{sub 3}{sup -} was restricted due to the very low but still detectable NR activity in the root and shoot tissue. Nevertheless, the mutant must have had supplementary means of assimilating considerable amounts of NO{sub 3}{sup -} over the experimental growth period. At the induced stage, both barley genotypes responded to tungstate treatments with a comparable but not complete depression of the NO{sub 3}{sup -} influx. Part of the NO{sub 3}{sup -} influx appears to be independent of the function of NR since an acceleration of the NO{sub 3}{sup -} uptake capacity to almost half the level of the controls occurred in both cultivars upon induction in spite of pretreatment with 150 micromolar WO{sub 4}{sup 2-} in a molybdenum-free solution prior to NO{sub 3}{sup -} induction. However, 600 micromolar tungstate treatment during the induction phase reduced NO{sub 3}{sup -} influx further (below 20%), but the plants of both cultivars were still able to recover almost completely. (author)

  13. Nitrile, amide and temperature effects on amidase-kinetics during acrylonitrile bioconversion by nitrile-hydratase/amidase in situ cascade system.

    Science.gov (United States)

    Cantarella, Laura; Gallifuoco, Alberto; Spera, Agata; Cantarella, Maria

    2013-08-01

    In this study the amidase kinetics of an in situ NHase/AMase cascade system was explored as a function of operational parameters such as temperature, substrate concentration and product formation. The results indicated that controlling amidase inactivation, during acrylonitrile bioconversion, makes it possible to recover the intermediate product of the two-step reaction in almost a pure form, without using purified enzyme. It has been demonstrated, in long-term experiments performed in continuous stirred UF-membrane bioreactors, that amidase is kinetically controlled by its proper substrate, depending on the structure, and by acrylonitrile. Using acrylamide, AMase-stability is temperature dependent (5°C, kd=0.008 h(-1); 30°C kd=0.023 h(-1)). Using benzamide, amidase is thermally stable up to 50°C and no substrate inhibition/inactivation occurs. With acrylonitrile, AMase-activity and -stability remain unchanged at concentrations <200 mM but at 200 mM, 35°C, after 70 h process, 90% irreversible inactivation occurs as no AMase-activity on benzamide revives. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. Synthesis of gels with basis of titanium tungstates as matrixes of radioactive generators; Sintesis de geles a base de titanio tungstenatos como matrices de generadores radiactivos

    Energy Technology Data Exchange (ETDEWEB)

    Galico C, L

    2005-07-01

    The heteropolyanions, compounds formed by the union of molybdates or tungstates polyanions with atoms of metals like zirconium, titanium, cerium, thorium, tin, etc., have been used as generator matrixes of {sup 99m} Tc or {sup 188} Re. Particularly they have been studied and produced successfully in our laboratory, generators of {sup 99} Mo/ {sup 99}m Tc at basis of gels zirconium molybdates and titanium molybdates. Considering that the molybdenum and tungsten, as well as the technetium and the rhenium, its belong to the same groups of transition metals, it is feasible that gels can be synthesized at basis of titanium tungstates, continuing a methodology similar to that of the gels titanium molybdates or zirconium molybdates, to produce generators {sup 188} W/ {sup 188} Re. The {sup 188} Re possess nuclear characteristics that make it attractive for therapeutic applications, since, it emits {beta}{sup -} particles of a great energy (2.12 MeV); joined to the possibility of being able to unite to different ligands (bifunctional agents) and biomolecules (antibodies or fragments of proteins), as it makes the {sup 99m} Tc, useful in radioimmunotherapy. Commercially the {sup 188} Re generators use a chromatographic column loaded with alumina where the {sup 188} Re, it is adsorbed and eluted the {sup 188} ReO{sub 4}{sup -} by means of a saline solution The alumina adsorbs around 0.2% of the {sup 188} Re, situation that forces to use {sup 188} Re of a high specific activity. The use of the gels technology, allows to work with medium or low specific activities of {sup 188} Re, opening the possibility of their production in countries whose nuclear capacity is medium or low. In particular, the synthesized gels with basis of titanium offer the possibility of being synthesized with non active material, for later on to be irradiated and directly produce the generator, since, the titanium {sup 51} Ti, unique radioisotope produced by the titanium, has a half life of 5.79 min. This

  15. Production of barium molybdate and tungstate on the base of ternary reciprocal Na, Ba long Cl, EhO4 (Eh - Mo, W) systems

    International Nuclear Information System (INIS)

    Garkushin, I.K.; Sechnoj, A.I.; Dibirov, M.A.; Trunin, A.S.

    1984-01-01

    Possibilities of the syntnesis of barium molybdate and tungstate on the base of ternary reciprocal Na, Ba parallel Cl, EhO 4 (Eh=Mo, W) system state diagrams are under study. It is shown that on the basis of these reciprocal state diagrams syntnesis of not only BaO 4 but also of other suhstances is possible. Purity of obtained chemical agents is basically dependent on qualification of initial components. Synthesis temperature is decreased and time is reduced as compared to other known methods. For substance synthesis, state diagrams examination (reaction type confirmation and component crystallization fields separation from compound crystallization fields) is necessary along with the calculation of the conventional thermochemical effect

  16. Synthesis, crystal structure and luminescent properties of a new pyrochlore type tungstate CsGa0.333W1.667O6

    Science.gov (United States)

    Zhao, Dan; Zhao, Ji; Fan, Yun-Chang; Ma, Zhao; Zhang, Rui-Juan; Liu, Bao-Zhong

    2018-06-01

    High temperature solution reaction leads to a new tungstate compound CsGa0.333W1.667O6, whose structure was determined by single-crystal X-ray diffraction analysis. The results show that it crystallizes in pyrochlore structure with cubic space group Fd-3m and a = 10.2529 (13) Å. In this structure, Ga and W atoms are in a statistical disorder manner. The self-activated luminescent properties CsGa0.333W1.667O6 were studied. Under the excitation of 323 nm, the emission spectrum exhibits a blue emission centered at 466 nm with the chromaticity coordinates (0.1838, 0.1814).

  17. Properties of complex tungstates, niobates, translated with fluorite-like structure. Svojstva slozhnykh vol'framatov, niobatov, tantalatov s flyuoritopodobnoj strukturoj

    Energy Technology Data Exchange (ETDEWEB)

    Vetkina, S N; Zolin, V F; Sirotinkin, V P; Smirnov, S A

    1989-04-01

    Spectra of ternary tungstates, niobates and tantalates (MeLa{sub 2}WO{sub 7}, La{sub 3}TO{sub 7}; Me=Ba, Sr; T=Ta, Nb) related to the layered fluorite group are analyzed. The laser pumping and time resolved luminescence are used for selecting spectra of unequivalent centers. The symmetry of the first center is near to the distorted cubic one. The vibrational spectra of europium in Eu{sub 3}NbO{sub 7} and SrLa{sub 2}WO{sub 7} are due to the chain-like structure of niobates and to the net-like structure of tantalates. The stimulated emission of Nd{sup 3+} in powders of BaLa{sub 2}WO{sub 7} and La{sub 3}NbO{sub 7} is observed at wavelengths of 1.07 and 1.063 {mu}m, respectively.

  18. Melt-processable hydrophobic acrylonitrile-based copolymer systems with adjustable elastic properties designed for biomedical applications.

    Science.gov (United States)

    Cui, J; Trescher, K; Kratz, K; Jung, F; Hiebl, B; Lendlein, A

    2010-01-01

    Acrylonitrile-based polymer systems (PAN) are comprehensively explored as versatile biomaterials having various potential biomedical applications, such as membranes for extra corporal devices or matrixes for guided skin reconstruction. The surface properties (e.g. hydrophilicity or charges) of such materials can be tailored over a wide range by variation of molecular parameters such as different co-monomers or their sequence structure. Some of these materials show interesting biofunctionalities such as capability for selective cell cultivation. So far, the majority of AN-based copolymers, which were investigated in physiological environments, were processed from the solution (e.g. membranes), as these materials are thermo-sensitive and might degrade when heated. In this work we aimed at the synthesis of hydrophobic, melt-processable AN-based copolymers with adjustable elastic properties for preparation of model scaffolds with controlled pore geometry and size. For this purpose a series of copolymers from acrylonitrile and n-butyl acrylate (nBA) was synthesized via free radical copolymerisation technique. The content of nBA in the copolymer varied from 45 wt% to 70 wt%, which was confirmed by 1H-NMR spectroscopy. The glass transition temperatures (Tg) of the P(AN-co-nBA) copolymers determined by differential scanning calorimetry (DSC) decreased from 58 degrees C to 20 degrees C with increasing nBA-content, which was in excellent agreement with the prediction of the Gordon-Taylor equation based on the Tgs of the homopolymers. The Young's modulus obtained in tensile tests was found to decrease significantly with rising nBA-content from 1062 MPa to 1.2 MPa. All copolymers could be successfully processed from the melt with processing temperatures ranging from 50 degrees C to 170 degrees C, whereby thermally induced decomposition was only observed at temperatures higher than 320 degrees C in thermal gravimetric analysis (TGA). Finally, the melt processed P

  19. Self-supported poly(methyl methacrylate-acrylonitrile-vinyl acetate)-based gel electrolyte for lithium ion battery

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Y.H.; Zhou, D.Y.; Rao, M.M.; Cai, Z.P.; Liang, Y. [School of Chemistry and Environment, South China Normal University, Guangzhou 510006 (China); Li, W.S.; Tan, C.L. [School of Chemistry and Environment, South China Normal University, Guangzhou 510006 (China); Key Lab of Electrochemical Technology on Energy Storage and Power Generation in Guangdong Universities, Guangzhou 510006 (China)

    2009-04-01

    Self-supported gel polymer electrolyte (GPE) was prepared based on copolymer, poly(methyl methacrylate-acrylonitrile-vinyl acetate) (P(MMA-AN-VAc)). The copolymer P(MMA-AN-VAc) was synthesized by emulsion polymerization and the copolymer membrane was prepared through phase inversion. The structure and the performance of the copolymer, the membrane and the GPE were characterized by FTIR, NMR, SEM, XRD, DSC/TG, LSV, CA, and EIS. It is found that the copolymer was formed through the breaking of double bond C=C in each monomer. The membrane has low crystallinity and has low glass transition temperature, 39.1 C, its thermal stability is as high as 310 C, and its mechanical strength is improved compared with P(MMA-AN). The GPE is electrochemically stable up to 5.6 V (vs. Li/Li{sup +}) and its conductivity is 3.48 x 10{sup -3} S cm{sup -1} at ambient temperature. The lithium ion transference number in the GPE is 0.51 and the conductivity model of the GPE is found to obey the Vogel-Tamman-Fulcher (VTF) equation. (author)

  20. Hybrid joining of polyamide and hydrogenated acrylonitrile butadiene rubber through heat-resistant functional layer of silane coupling agent

    Science.gov (United States)

    Sang, Jing; Sato, Riku; Aisawa, Sumio; Hirahara, Hidetoshi; Mori, Kunio

    2017-08-01

    A simple, direct adhesion method was developed to join polyamide (PA6) to hydrogenated acrylonitrile butadiene rubber (HNBR) by grafting a functional layer of a silane coupling agent on plasma functionalized PA6 surfaces. The functional layer of the silane coupling agent was prepared using a self-assembly method, which greatly improved the heat resistance of PA6 from 153 °C up to 325 °C and the resulting PA6/HNBR joints showed excellent adhesion properties with cohesive failure between PA6 and HNBR. X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and nanoscale infrared microscopy and chemical imaging (Nano-IR, AFM-IR) were employed to characterize the surfaces and interfaces. The Nano-IR analysis method was employed for the first time to analyze the chemical structures of the adhesion interfaces between different materials and to establish the interface formation mechanism. This study is of significant value for interface research and the study of adhesion between resins and rubbers. There is a promising future for heat-resistant functional layers on resin surfaces, with potential application in fuel hose composite materials for the automotive and aeronautical industries.

  1. Carboxyl-terminated butadiene-acrylonitrile-toughened epoxy/carboxyl-modified carbon nanotube nanocomposites: Thermal and mechanical properties

    Directory of Open Access Journals (Sweden)

    H. F. Xie

    2012-09-01

    Full Text Available Carboxyl-modified multi-walled carbon nanotubes (MWCNT–COOHs as nanofillers were incorporated into diglycidyl ether of bisphenol A (DGEBA toughened with carboxyl-terminated butadiene-acrylonitrile (CTBN. The carboxyl functional carbon nanotubes were characterized by Fourier-transform infrared spectroscopy and thermogravimetric analysis. Furthermore, cure kinetics, glass transition temperature (Tg, mechanical properties, thermal stability and morphology of DGEBA/CTBN/MWCNT–COOHs nanocomposites were investigated by differential scanning calorimetry (DSC, dynamic mechanical analysis (DMA, universal test machine, thermogravimetric analysis and scanning electron microscopy (SEM. DSC kinetic studies showed that the addition of MWCNT–COOHs accelerated the curing reaction of the rubber-toughened epoxy resin. DMA results revealed that Tg of rubber-toughened epoxy nanocomposites lowered with MWCNT–COOH contents. The tensile strength, elongation at break, flexural strength and flexural modulus of DGEBA/CTBN/MWCNT-COOHs nanocomposites were increased at lower MWCNT-COOH concentration. A homogenous dispersion of nanocomposites at lower MWCNT–COOH concentration was observed by SEM.

  2. Some regularities of separate and simultaneous radiation polymerization of vinyl acetate and acrylonitrile in adsorption layer on aerosil surface

    International Nuclear Information System (INIS)

    Mund, S.L.; Bruk, M.A.; Abkin, A.D.

    1976-01-01

    The kinetics has been studied of initial stage radiation copolymerization and separate radiation polymerization of aerosil adsorbed vinylacetate (VA) and acrylonitrile (AN). The monomers were irradiated using a Co 60 gamma source or a RUP-400 X-ray unit. Infrared spectroscopy, nuclear magnetic resonance and gravimetry were used in the study. It has been found that in the dose rate interval studied (over 60-450 rad./sec) the break of kinetic chains during the polymerization of VA and its mixtures with AN is due to the reaction of degenerate transfer of the chains to the surface hydroxyl groups. When AN is polymerized, biomolecular break of chains prevails. The effective activation energy of polymerization is 1.5 kcal/mol for VA and 2.5 kcal/mol for AN. The order of polymerization rates by the concentration of adsorbed monomers at 50 deg, as well as by the irradiation dose rate is equal to 1 and 1 for VA and 3/2 and 0.7 for AN, respectively. The calculated values of copolymerization constants coincide with those characteristic of their radical polymerization in liquid phase. Isotherms for adsorption of VA and AN on aerosil at 30, 50 and 70 deg have been studied [ru

  3. Proposal of the Tubular Daylight System Using Acrylonitrile Butadiene Styrene (ABS Metalized with Aluminum for Reflective Tube Structure

    Directory of Open Access Journals (Sweden)

    Anderson Diogo Spacek

    2018-01-01

    Full Text Available In the search for alternatives to reduce the consumption of electric energy, the possibility of using natural light for lighting through TDD (tubular daylight devices or TDGS (tubular daylight guidance systems appears. These natural luminaires are used in rooms where you want to save electricity and enjoy the benefits of natural light. The present work proposes the construction of a tubular system for the conduction of natural light that replaces aluminum with silver (currently marketed by several companies by polymer metallized with aluminum, offering a low cost. The polymer acrylonitrile butadiene styrene (ABS, coated with aluminum by physical vapor deposition (ionization, was evaluated for some tests to verify characteristics of the structure and the metallized surface. After the tests, the construction of the reflective tube was performed and validated in a real scale of application. The results proved the technical viability of the proposed tube construction for the realization of direct sunlight for illumination using polymeric material. Although it has produced 35% less than the reference tube, it can be marketed at an estimated cost of 50% less.

  4. Free radical induced grafting of acrylonitrile on pre-treated rice straw for enhancing its durability and flame retardancy

    Directory of Open Access Journals (Sweden)

    Aparna Mukherjee

    2017-01-01

    Full Text Available The present investigation highlights the feasibility of a polymer grafting process to enhance the durability and flame retardancy of rice straw towards application as a low cost roofing material. The success of this grafting methodology was perceived to depend upon a bi-step pre-treatment process encompassing delignification and inorganic salts dispersion. Subsequently free radical polymer grafting of acrylonitrile onto rice straw was implemented by immersion mechanism initiated by oxalic acid-potassium permanganate initiator. The percentage of grafting, limiting oxygen index (LOI, biodegradability of the grafted rice straw and grafting yield percentage was estimated to be 57%, 27%, 0.02% and 136.67%, respectively. The weight loss of polymer grafted rice straw implied its less biodegradability over raw straw. Thus, the process of grafting contrived in the present analysis can be a promising and reliable technique for the efficient utilization of rice straw as an inexpensive roofing element through the augmentation of its durability and flame retardancy.

  5. Acrylonitrile exposure assessment in the emergency responders of a major train accident in Belgium: a human biomonitoring study.

    Science.gov (United States)

    Van Nieuwenhuyse, A; Fierens, S; De Smedt, T; De Cremer, K; Vleminckx, C; Mertens, B; Van Overmeire, I; Bader, M; De Paepe, P; Göen, T; Nemery, B; Schettgen, T; Stove, C; Van Oyen, H; Van Loco, J

    2014-12-15

    On May 4, 2013, a train transporting chemicals derailed in Wetteren, Belgium. Several tanks loaded with acrylonitrile (ACN) exploded, resulting in a fire and a leakage of ACN. To determine exposure to ACN and to assess discriminating factors for ACN exposure in the emergency responders involved in the on-site management of the train accident. The study population consisted of 841 emergency responders. Between May 21 and June 28, they gave blood for the determination of N-2-cyanoethylvaline (CEV) hemoglobin adducts and urine for the measurement of cotinine. They also filled in a short questionnaire. 163 (26%) non-smokers and 55 (27%) smokers showed CEV concentrations above the reference values of 10 and 200 pmol/g globin, respectively. The 95th percentile in the non-smokers was 73 pmol/g globin and the maximum was 452 pmol/g globin. ACN exposure among the non-smokers was predicted by (1) the distance to the accident, (2) the duration of exposure, and (3) the occupational function. Emergency responders involved in the on-site management of the train accident were clearly exposed to ACN from the accident. However, the extent of exposure remained relatively moderate with CEV concentrations staying within the ranges described in literature as background for a smoking population. Moreover, the exposure was less pronounced in the emergency responders as compared to that in the local population. Copyright © 2014. Published by Elsevier Ireland Ltd.

  6. Preparation of Mesoporous Carbons from Acrylonitrile-methyl Methacrylate Copolymer/Silica Nanocomposites Synthesized by in-situ Emulsion Polymerization

    Institute of Scientific and Technical Information of China (English)

    BAO Yongzhong; ZHAO Wenting; HUANG Zhiming

    2013-01-01

    Acrylonitrile-methyl methacrylate (AN-MMA) copolymer/silica nanocomposites were synthesized by in-situ emulsion polymerization initiated by 2,2′-azobis(2-amidinopropane) dihydrochloride absorbed onto colloidal silica particles,and the mesoporous carbon materials were prepared through carbonization of the obtained AN-MMA copolymer/silica nanocomposites,followed by HF etching.Thermogravimetric analysis of AN-MMA copolymer/silica nanocomposites showed that the carbon yield of copolymer was slightly decreased as silica particle incorporated.N2 adsorption-desorption,scan electron microscopy (SEM) and transmission electron microscopy (TEM) were used to characterize the structure and morphology of the mesoporous carbon materials.Both SEM and TEM results showed that disordered mesopores were formed in the obtained carbon material mainly through templating effect of silica nanoparticles.The diameter of mesopores was mainly distributed in the range from 5 nm to 15 nm.The mean pore diameter and total pore volume of the material increased as the mass fraction of silica in the nanocomposites increased from 0 to 24.93%.The significant increase of the mean pore diameter and the decrease of surface area for the carbon material prepared from the nanocomposite with 24.93% silica were caused by partial aggregation of silica nanoparticles in the polymer matrix.

  7. Electron Beam Damage in Poly(Vinyl Chloride) and Poly(Acrylonitrile) as Observed by Auger Electron Spectroscopy

    International Nuclear Information System (INIS)

    Lea, Alan S.; Engelhard, Mark H.; Baer, Donald R.

    2003-01-01

    AES spectra of spun-cast films of poly(vinyl chloride) (PVC) and poly(acrylonitrile) (PAN) were collected over a period of time to determine specimen damage during exposure to a 10kV electron beam. For the PVC, loss of chlorine was observed over a period of 203 minutes to the extent that the final chlorine concentration was only 20% of its original value. PAN exhibited a loss in nitrogen content over a period of 120 minutes, but the rate of damage to the polymer was significantly less than PVC. Figure 1 shows the atomic concentration in the PVC film as a function of dose (time). It takes a dose of approximately 7.0x10-5 Ccm-5 for the chlorine concentration to fall from its original value by 10% (one definition of critical dose). Figure 2 shows a similar drop in nitrogen concentration in the PAN film as a function of dose. For this polymer, it takes a dose of 1.3x10-3 Ccm-2 for the nitrogen concentration to fall by 10%

  8. Separation of polycarbonate and acrylonitrile-butadiene-styrene waste plastics by froth flotation combined with ammonia pretreatment.

    Science.gov (United States)

    Wang, Chong-Qing; Wang, Hui; Liu, Qun; Fu, Jian-Gang; Liu, You-Nian

    2014-12-01

    The objective of this research is flotation separation of polycarbonate (PC) and acrylonitrile-butadiene-styrene (ABS) waste plastics combined with ammonia pretreatment. The PC and ABS plastics show similar hydrophobicity, and ammonia treatment changes selectively floatability of PC plastic while ABS is insensitive to ammonia treatment. The contact angle measurement indicates the dropping of flotation recovery of PC is ascribed to a decline of contact angle. X-ray photoelectron spectroscopy demonstrates reactions occur on PC surface, which makes PC surface more hydrophilic. Separation of PC and ABS waste plastics was conducted based on the flotation behavior of single plastic. At different temperatures, PC and ABS mixtures were separated efficiently through froth flotation with ammonia pretreatment for different time (13 min at 23 °C, 18 min at 18 °C and 30 min at 23 °C). For both PC and ABS, the purity and recovery is more than 95.31% and 95.35%, respectively; the purity of PC and ABS is up to 99.72% and 99.23%, respectively. PC and ABS mixtures with different particle sizes were separated effectively, implying that ammonia treatment possesses superior applicability. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Surface treatment with Fenton for separation of acrylonitrile-butadiene-styrene and polyvinylchloride waste plastics by flotation.

    Science.gov (United States)

    Wang, Jian-Chao; Wang, Hui; Huang, Luo-Luo; Wang, Chong-Qing

    2017-09-01

    Surface treatment with Fenton was applied to flotation separation of acrylonitrile-butadienestyrene (ABS) and polyvinylchloride (PVC). After treatment, the floatability of ABS has a dramatic decrease, while the floatability of PVC is not affected. Fourier transform infrared spectroscopy (FT-IR) spectra and X-ray photoelectron spectroscopy (XPS) spectra were recorded to ascertain the mechanism of Fenton treatment. FT-IR and XPS analysis confirms that the introduction of oxygen-containing group occurs on the surface of ABS. The optimum conditions are molar ration (H 2 O 2 :Fe 2+ ) 10000, H 2 O 2 concentration 0.4M/L, pH 5.8, treatment time 2min and temperature 25°C, frother concentration 15mg/L and flotation time 3min. Particle sizes and mixing ratios were also investigated. Plastic mixtures of ABS and PVC with different particle sizes and mixing ratios can be effectively separated. The purity of ABS and PVC are up to 100% and 99.78%, respectively; the recovery of ABS and PVC are up to 99.89% and 100%, respectively. A practical, environmentally friendly and effective reagent, namely Fenton, was originally applied to surface treatment of ABS and PVC waste plastics for flotation separation of their mixtures. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Low content Ag-coated poly(acrylonitrile) microspheres and graphene for enhanced microwave absorption performance epoxy composites

    Science.gov (United States)

    Zhang, Bin; Wang, Jun; Chen, Xiaocheng; Su, Xiaogang; Zou, Yi; Huo, Siqi; Chen, Wei; Wang, Junpeng

    2018-04-01

    Silver nanoparticles was uniformly anchored on the surface of hollow poly(acrylonitrile) microspheres with a facile chemical method using hydrazine hydrate as reductant. Integrating these conducting hollow spheres (PANS@Ag) with chemical reduced graphene oxide (RGO) dispersed in epoxy resin, a lightweight microwave absorber was successfully prepared with enhanced microwave absorption performance. The chemical constitution and surface morphology of as-synthesized RGO and PANS@Ag powders were characterized by XRD, XPS, FE-SEM and SAED, while the electromagnetic properties of these different proportion PANS@Ag-RGO/EP samples were analyzed through vector network analyzer (VNA). The minimum reflection loss (RL) could reach up to ‑28.1 dB at 8.8 GHz with a layer thickness of 2 mm, and the corresponding effective absorption bandwidth (RL values less than ‑10 dB) was from 7.9 GHz to 9.8 GHz. However, the dosage of PANS@Ag and RGO was merely 3 wt% and 1 wt%, respectively. As the content of PANS@Ag powders decreased to 1 wt%, the PANS@Ag-RGO/EP samples still retained effective microwave absorption performance and the optimal RL was ‑14.7 dB. The density of as-prepared absorbers was in the range of 0.49 ∼ 0.87 g cm‑3. The low content, low density and enhanced microwave absorption performance endow the hybrid composites with competitive application prospect in stealth technology field.

  11. The effect of distribution of monomer moiety on the pH response and mechanical properties of poly(acrylonitrile-co-acrylic acid) copolymers

    International Nuclear Information System (INIS)

    Sahoo, Anasuya; Jassal, Manjeet; Agrawal, Ashwini K

    2010-01-01

    The pH response and mechanical properties of copolymer-based hydrogels such as poly(acrylonitrile-co-acrylic acid) are usually attributed to their chemical composition. In this study, it has been shown that the architecture of the polymer chains, i.e. the distribution of comonomers in the macromolecules, also plays a major role in controlling these properties. A series of four poly(acrylonitrile-co-acrylic acids) with fixed composition (i.e. ∼30 mol% acrylic acid moieties) were synthesized, where the block lengths of both AN (acrylonitrile) and AAc (acrylic acid) moieties in the copolymers were varied by controlling the feeding pattern of the monomers during free radical copolymerization. These copolymers were then converted into fine fibers of the same dimensions. The monomer distribution in the four copolymers was estimated using quantitative carbon 13 C nuclear magnetic resonance (NMR) and related to the mechanical and pH response properties of the resultant fibers. The pH response of the fibers with similar composition increased dramatically as the block length of the AAc moiety was increased, while the mechanical properties increased as a direct function of the block length of the AN moieties. The fiber's response at pH 10 in terms of the change in length increased by ∼four times while its response rate increased by ∼50 times with the increase in block length of the AAc moiety. On the other hand, the tensile properties and retractive stress increased by ∼four times with the increase in the block length of the AN moiety

  12. The effect of distribution of monomer moiety on the pH response and mechanical properties of poly(acrylonitrile-co-acrylic acid) copolymers

    Science.gov (United States)

    Sahoo, Anasuya; Jassal, Manjeet; Agrawal, Ashwini K.

    2010-02-01

    The pH response and mechanical properties of copolymer-based hydrogels such as poly(acrylonitrile-co-acrylic acid) are usually attributed to their chemical composition. In this study, it has been shown that the architecture of the polymer chains, i.e. the distribution of comonomers in the macromolecules, also plays a major role in controlling these properties. A series of four poly(acrylonitrile-co-acrylic acids) with fixed composition (i.e. ~30 mol% acrylic acid moieties) were synthesized, where the block lengths of both AN (acrylonitrile) and AAc (acrylic acid) moieties in the copolymers were varied by controlling the feeding pattern of the monomers during free radical copolymerization. These copolymers were then converted into fine fibers of the same dimensions. The monomer distribution in the four copolymers was estimated using quantitative carbon 13C nuclear magnetic resonance (NMR) and related to the mechanical and pH response properties of the resultant fibers. The pH response of the fibers with similar composition increased dramatically as the block length of the AAc moiety was increased, while the mechanical properties increased as a direct function of the block length of the AN moieties. The fiber's response at pH 10 in terms of the change in length increased by ~four times while its response rate increased by ~50 times with the increase in block length of the AAc moiety. On the other hand, the tensile properties and retractive stress increased by ~four times with the increase in the block length of the AN moiety.

  13. Hybrid joining of polyamide and hydrogenated acrylonitrile butadiene rubber through heat-resistant functional layer of silane coupling agent

    Energy Technology Data Exchange (ETDEWEB)

    Sang, Jing; Sato, Riku [Department of Frontier Materials and Function Engineering, Graduate School of Engineering, Iwate University, 4-3-5 Ueda, Morioka 020-8551 (Japan); Aisawa, Sumio, E-mail: aisawa@iwate-u.ac.jp [Department of Frontier Materials and Function Engineering, Graduate School of Engineering, Iwate University, 4-3-5 Ueda, Morioka 020-8551 (Japan); Hirahara, Hidetoshi [Department of Frontier Materials and Function Engineering, Graduate School of Engineering, Iwate University, 4-3-5 Ueda, Morioka 020-8551 (Japan); Mori, Kunio [Department of Frontier Materials and Function Engineering, Graduate School of Engineering, Iwate University, 4-3-5 Ueda, Morioka 020-8551 (Japan); Sulfur Chemical Institute, 210, Collabo MIU, 4-3-5, Ueda, Morioka 020-0066 (Japan)

    2017-08-01

    Highlights: • We modify PA6 surface using silane coupling agent layer of APTMS to link HNBR. • APTMS greatly improved heat resistance of PA6 from 153 °C up to 325 °C. • A PA6/HNBR joined body was obtained, and it exhibits high adhesion strength with cohesive failure. • Chemical structures of the adhesion interfaces of PA6/HNBR were confirmed by Nano-IR. - Abstract: A simple, direct adhesion method was developed to join polyamide (PA6) to hydrogenated acrylonitrile butadiene rubber (HNBR) by grafting a functional layer of a silane coupling agent on plasma functionalized PA6 surfaces. The functional layer of the silane coupling agent was prepared using a self-assembly method, which greatly improved the heat resistance of PA6 from 153 °C up to 325 °C and the resulting PA6/HNBR joints showed excellent adhesion properties with cohesive failure between PA6 and HNBR. X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and nanoscale infrared microscopy and chemical imaging (Nano-IR, AFM-IR) were employed to characterize the surfaces and interfaces. The Nano-IR analysis method was employed for the first time to analyze the chemical structures of the adhesion interfaces between different materials and to establish the interface formation mechanism. This study is of significant value for interface research and the study of adhesion between resins and rubbers. There is a promising future for heat-resistant functional layers on resin surfaces, with potential application in fuel hose composite materials for the automotive and aeronautical industries.

  14. Effects of ageing conditions on degradation of acrylonitrile butadiene rubber filled with heat-treated ZnO star-shaped particles in rapeseed biodiesel

    OpenAIRE

    Akhlaghi, Shahin; Pourrahimi, A. M.; Christian, Sjöstedt; Martin, Bellander; Mikael S., Hedenqvist; Ulf W., Gedde

    2017-01-01

    The degradation of acrylonitrile butadiene rubber (NBR) after exposure to biodiesel at different oxygen partial pressures in an automated ageing equipment at 80 °C, and in a high-pressure autoclave at 150 °C was studied. The oxidation of biodiesel was promoted by an increase in oxygen concentration, resulting in a larger uptake of fuel in the rubber due to internal cavitation, a greater decrease in the strain-at-break of NBR due to the coalescence of cavity, and a faster increase in the cross...

  15. Estimation of degree of polymerization of poly-acrylonitrile-grafted carbon nanotubes using Guinier plot of small angle x-ray scattering.

    Science.gov (United States)

    Cho, Hyunjung; Jin, Kyeong Sik; Lee, Jaegeun; Lee, Kun-Hong

    2018-07-06

    Small angle x-ray scattering (SAXS) was used to estimate the degree of polymerization of polymer-grafted carbon nanotubes (CNTs) synthesized using a 'grafting from' method. This analysis characterizes the grafted polymer chains without cleaving them from CNTs, and provides reliable data that can complement conventional methods such as thermogravimetric analysis or transmittance electron microscopy. Acrylonitrile was polymerized from the surface of the CNTs by using redox initiation to produce poly-acrylonitrile-grafted CNTs (PAN-CNTs). Polymerization time and the initiation rate were varied to control the degree of polymerization. Radius of gyration (R g ) of PAN-CNTs was determined using the Guinier plot obtained from SAXS solution analysis. The results showed consistent values according to the polymerization condition, up to a maximum R g  = 125.70 Å whereas that of pristine CNTs was 99.23 Å. The dispersibility of PAN-CNTs in N,N-dimethylformamide was tested using ultraviolet-visible-near infrared spectroscopy and was confirmed to increase as the degree of polymerization increased. This analysis will be helpful to estimate the degree of polymerization of any polymer-grafted CNTs synthesized using the 'grafting from' method and to fabricate polymer/CNT composite materials.

  16. Acrylonitrile exposure: the effect on p53 and p21WAF1 protein levels in the blood plasma of occupationally exposed workers and in vitro in human diploid lung fibroblasts

    Czech Academy of Sciences Publication Activity Database

    Rössner ml., Pavel; Binková, Blanka; Chvátalová, Irena; Šrám, Radim

    č. 517 (2002), s. 239-250 ISSN 0027-5107 R&D Projects: GA MŽP SI/340/1/97 Institutional research plan: CEZ:AV0Z5039906 Keywords : Acrylonitrile * p53 protein * p21WAF1 protein Subject RIV: DN - Health Impact of the Environment Quality Impact factor: 3.158, year: 2002

  17. Phase diagrams of KY(WO4)2-KEr(WO4)2, KGd(WO4)2-KEr(WO4)2 systems and single crystal growth for some tungstates

    International Nuclear Information System (INIS)

    Yudanova, L.I.; Pavlyuk, A.A.; Potapova, O.G.

    1992-01-01

    Phase diagrams of the KY(WO 4 ) 2 -KEr(WO 4 ) 2 , KGd(WO 4 ) 2 -KEr(WO 4 ) 2 systems were studied by differential thermal and X-ray diffraction analyses. Continuous variety of solid solutions are in the KY(WO 4 ) 2 -KEr(WO 4 ) 2 system. They occurred just as in the area of alphaso beta-modifications. Limited areas of the solid solutions based on components were in the KGd(WO 4 ) 2 -KEr(WO 4 ) 2 system. Monocrystals of potassium-yttrium and potassium-gadolinium tungstates activated by erbium were grown using modified low-gradient Czochralski method

  18. Use of combined ion exchangers on the basis of KU-23 and KM-2p cation exchangers for purification of ammonium molybdate and tungstate solutions from phosphate, arsenate, and silicate impurities

    International Nuclear Information System (INIS)

    Blokhin, A.A.; Majorov, D.Yu.; Kopyrin, A.A.; Taushkanov, V.P.

    2002-01-01

    Using the Tracer technique ( 32 P) and elementary analysis, potentiality of using combined ionites on the basis of macroporous cation-exchange resins KU-23 or KM-2p and hydrated zirconium oxide for purification of concentrated solutions of ammonium molybdate and tungstate from phosphate-, arsenate-, and silicate-ions impurities was studied. High selectivity of the combined ionites towards impurity ions was ascertained, which permits reducing the content of impurities by a factor of 50-100 compared with the initial one [ru

  19. Influences of Temperature on the Conversion of Ammonium Tungstate Pentahydrate to Tungsten Oxide Particles with Controllable Sizes, Crystallinities, and Physical Properties

    Directory of Open Access Journals (Sweden)

    Asep Bayu Dani Nandiyanto

    2016-08-01

    Full Text Available The purpose of this study was to investigate influences of temperature on the conversion of ammonium tungstate pentahydrate (ATP powder to tungsten trioxide (WO3 particles with controllable sizes, crystallinities, and physicochemical properties. In this study, we used a simple thermal decomposition method. In the experimental procedure, we explored the effect of temperature on the physicochemical properties of ATP by testing various heating temperatures (from 100 to 900 °C. The heated ATP samples were then characterized by a physical observation (i.e. color and various analysis methods (i.e. a thermal gravimetric and differential thermal analysis, infrared spectroscopy, an X-ray diffraction, and a scanning electron microscope. Experimental results showed that increases in temperature had an impact to the decreases in particle size, the change in material crystallinity, and the change in physical properties (e.g. change of color from white, orange, to yellowish green. The relationships between the reaction temperatures and the physicochemical properties of the ATP were also investigated in detail along with the theoretical consideration and the proposal of the WO3 particle formation mechanism. In simplification, the phenomena can be described into three zones of temperatures. (1 Below 250 °C (release of water molecules and some ammonium ions.; (2 At 250-400 °C (release of water molecules and ammonium ions, restructurization of tungsten and oxygen elements, and formation of amorphous tungsten trioxide. (3 At higher than 400 °C (crystallization of tungsten trioxide. Since ATP possessed reactivity on temperature, its physicochemical properties changing could be observed easily, and the experimental procedure could be done easily. The present study will benefit not only for “chemistry and material science” but also potentially to be used as a model material for explaining the thermal behavior of material to undergraduate students (suitable

  20. Technical Note: A simulation study on the feasibility of radiotherapy dose enhancement with calcium tungstate and hafnium oxide nano- and microparticles.

    Science.gov (United States)

    Sherck, Nicholas J; Won, You-Yeon

    2017-12-01

    To assess the radiotherapy dose enhancement (RDE) potential of calcium tungstate (CaWO 4 ) and hafnium oxide (HfO 2 ) nano- and microparticles (NPs). A Monte Carlo simulation study was conducted to gauge their respective RDE potentials relative to that of the broadly studied gold (Au) NP. The study was warranted due to the promising clinical and preclinical studies involving both CaWO 4 and HfO 2 NPs as RDE agents in the treatment of various types of cancers. The study provides a baseline RDE to which future experimental RDE trends can be compared to. All three materials were investigated in silico with the software Penetration and Energy Loss of Positrons and Electrons (PENELOPE 2014) developed by Francesc Salvat and distributed in the United States by the Radiation Safety Information Computational Center (RSICC) at Oak Ridge National Laboratory. The work utilizes the extensively studied Au NP as the "gold standard" for a baseline. The key metric used in the evaluation of the materials was the local dose enhancement factor (DEF loc ). An additional metric used, termed the relative enhancement ratio (RER), evaluates material performance at the same mass concentrations. The results of the study indicate that Au has the strongest RDE potential using the DEF loc metric. HfO 2 and CaWO 4 both underperformed relative to Au with lower DEF loc of 2-3 × and 4-100 ×, respectively. The computational investigation predicts the RDE performance ranking to be: Au > HfO 2 > CaWO 4 . © 2017 American Association of Physicists in Medicine.

  1. The influence of nano silica particles on gamma-irradiation ageing of elastomers based on chlorosulphonated polyethylene and acrylonitrile butadiene rubber

    Science.gov (United States)

    Marković, G.; Marinović-Cincović, M.; Tanasić, Lj.; Jovanović, V.; Samaržija-Jovanović, S.; Vukić, N.; Budinski-Simendić, J.

    2011-12-01

    The goal of this work was to study gamma irradiation ageing of rubber blends based on acrylonitrile butadiene rubber (NBR) and chlorosulphonated polyethylene rubber (CSM) reinforced by silica nano particles. The NBR/CSM compounds (50: 50, w/w) filled with different content of filler (0-100 phr) were crosslinked by sulfur. The vulcanization characteristics were assessed using the rheometer with an oscillating disk. The vulcanizates were prepared in a hydraulic press. The obtained materials were exposed to the different irradiation doses (100, 200, 300 and 400 kGy). The mechanical properties (hardness, modulus at 100% elongation, tensile strength and elongation at break) and swelling numbers were assessed before and after gamma irradiation ageing.

  2. Synchrotron-based FTIR microspectroscopy for the mapping of photo-oxidation and additives in acrylonitrile-butadiene-styrene model samples and historical objects.

    Science.gov (United States)

    Saviello, Daniela; Pouyet, Emeline; Toniolo, Lucia; Cotte, Marine; Nevin, Austin

    2014-09-16

    Synchrotron-based Fourier transform infrared micro-spectroscopy (SR-μFTIR) was used to map photo-oxidative degradation of acrylonitrile-butadiene-styrene (ABS) and to investigate the presence and the migration of additives in historical samples from important Italian design objects. High resolution (3×3 μm(2)) molecular maps were obtained by FTIR microspectroscopy in transmission mode, using a new method for the preparation of polymer thin sections. The depth of photo-oxidation in samples was evaluated and accompanied by the formation of ketones, aldehydes, esters, and unsaturated carbonyl compounds. This study demonstrates selective surface oxidation and a probable passivation of material against further degradation. In polymer fragments from design objects made of ABS from the 1960s, UV-stabilizers were detected and mapped, and microscopic inclusions of proteinaceous material were identified and mapped for the first time. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Compatibilization of acrylonitrile-butadiene-styrene terpolymer/poly(ethylene glycol-co-1,4-cyclohexanedimethanol terephthalate) blend: effect on morphology, interface, mechanical properties and hydrophilicity

    Science.gov (United States)

    Chen, Tingting; Zhang, Jun

    2018-04-01

    The compatibilization of acrylonitrile-butadiene-styrene terpolymer (ABS) and poly(ethylene glycol-co-1,4-cyclohexanedimethanol terephthalate) (PETG) blends was first investigated. Styrene-acrylonitrile-glycidyl methacrylate terpolymer (SAG) and ABS grafted with maleic anhydride (ABS-g-MAH) were selected as reactive compatibilizers for the ABS/PETG blends. The compatibilization effect was assessed by scanning electron microscope (SEM), differential scanning calorimetry (DSC) and mechanical properties. And the effect of compatibilizers on the hydrophilicity of the blends was evaluated as well. SEM observation and DSC analysis confirmed that both SAG and ABS-g-MAH compatibilizers could improve the compatibility between ABS and PETG, leading to an improvement in toughness of the blend. The possible cause for the improvement of compatibility was the reaction between compatibilizers and PETG, which could in situ turn out compatibilizers that acted as interfacial agents to enhance the interfacial interaction in the blend. Especially, the addition of SAG significantly decreased the dispersion phase size and the interface voids almost disappeared. Since the in situ reactions between the epoxy groups of SAG and the end groups (sbnd COOH or sbnd OH) of PETG generated PETG-co-SAG copolymer at the blend interface, and the cross-linking reactions proposed to take place between SAG and the PETG-co-SAG copolymer, acting as compatibilizer, could significantly increase the interfacial interaction. The addition of SAG also enhanced the stiffness of the blends. Moreover, the addition of SAG made the blend more hydrophilic, whereas the addition of ABS-g-MAH made the blend more hydrophobic. Therefore, SAG was a good compatibilizer for the ABS/PETG blends and could simultaneously provide the blends with toughening, stiffening and hydrophilic effects.

  4. Synthesis and characterization of poly-o-anisidine Sn(IV tungstate: A new and novel ‘organic–inorganic’ nano-composite material and its electro-analytical applications as Hg(II ion-selective membrane electrode

    Directory of Open Access Journals (Sweden)

    Asif A. Khan

    2012-07-01

    Full Text Available An organic–inorganic nano-composite poly-o-anisidine Sn(IV tungstate was chemically synthesized by sol–gel mixing of the incorporation of organic polymer o-anisidine into the matrices of inorganic ppt of Sn(IV tungstate in different mixing volume ratios. This composite material has been characterized using various analytical techniques like XRD (X-ray diffraction, FTIR (Fourier transform infrared, SEM (Scanning electron microscopy, TEM (Transmission electron microscopy and simultaneous TGA (Thermogravimetric analysis studies. On the basis of distribution studies, the material was found to be highly selective for Hg(II. Using this nano-composite cation exchanger as electro-active material, a new heterogeneous precipitate based on ion-sensitive membrane electrode was developed for the determination of Hg(II ions in solutions. The membrane electrode was mechanically stable, with a quick response time, and can be operated within a wide pH range. The electrode was also found to be satisfactory in electrometric titrations.

  5. Studies on {sup 99}Mo-{sup 99m}Tc adsorption and elution behaviors using the inorganic sorbent ceric tungstate and conventional organic resins

    Energy Technology Data Exchange (ETDEWEB)

    El-Sweify, Fatma H.; Fattah, Alaa El-Din A. Abdel; Aly, Shorouk M.; Ghamry, Mohamed A. [Atomic Energy Authority, Cairo (Egypt). Hot Laboratories Center; El-Sheikh, Ragaa [Zagazig Univ. (Egypt). Chemistry Dept.

    2017-09-01

    Adsorption behavior of {sup 99}Mo(VI) and {sup 99m}Tc(VII) was studied on ceric tungstate (CeW) and compared with the adsorption on the conventional cation and anion exchangers Dowex-50X8 and AG-2X8, respectively. The studies were carried out under static and dynamic conditions. The effect of contact time and pH on the adsorption was investigated under static conditions. High K{sub d}-values for sorption of {sup 99}Mo(VI) on (CeW) were obtained over the investigated pH range. {sup 99m}Tc was adsorbed with much lower K{sub d}-values. The K{sub d}-values were pH dependent. K{sub d}-values of {sup 99}Mo-adsorption on AG-2X8 were lower than those on (CeW) and vice versa for {sup 99m}Tc. Ionic species of both elements were not adsorbed on Dowex-50X8, indicating the absence of cationic species and the adsorption of both elements on AG-2X8 and (CeW) as anionic species. The loading and elution behaviors of {sup 99}Mo and {sup 99m}Tc on (CeW) were studied using different eluents. {sup 99}Mo remained strongly adsorbed under all conditions whereas {sup 99m}Tc was easily eluted. Adsorption of some fission products, i.e. {sup 95}Zr(IV) and {sup 95}Nb(V), in addition to {sup 123m}Te(IV) and {sup 75}Se(IV), as representatives of their corresponding fission product isotopes, as well as {sup 181}Hf, as probable radioactive contaminant was also studied. Solutions of the ionic species of those metals were loaded in mixtures together with {sup 99}Mo on (CeW) columns. Strong adsorption of those ionic species and {sup 99}Mo on (CeW) was found whereas {sup 99m}Tc was easily eluted. Different eluents were investigated for eluting {sup 99m}Tc from {sup 99}Mo-adsorbed on (CeW).

  6. Evaluation of image uniformity and radiolucency for computed tomography phantom made of 3-dimensional printing of fused deposition modeling technology by using acrylonitrile but audience styrene resin

    Energy Technology Data Exchange (ETDEWEB)

    Seoung, Youl Hun [Dept. of of Radiological Science, Cheongju University, Cheongju (Korea, Republic of)

    2016-09-15

    The purpose of this study was to evaluate the radiolucency for the phantom output to the 3D printing technology. The 3D printing technology was applied for FDM (fused deposition modeling) method and was used the material of ABS (acrylonitrile butadiene styrene) resin. The phantom was designed in cylindrical uniformity. An image uniformity was measured by a cross-sectional images of the 3D printed phantom obtained from the CT equipment. The evaluation of radiolucency was measured exposure dose by the inserted ion-chamber from the 3D printed phantom. As a results, the average of uniformity in the cross-sectional CT image was 2.70 HU and the correlation of radiolucency between PMMA CT phantom and 3D printed ABS phantom is found to have a high correlation to 0.976. In the future, this results will be expected to be used as the basis for the phantom production of the radiation quality control by used 3D printing technology.

  7. Successful startup of a full-scale acrylonitrile wastewater biological treatment plant (ACN-WWTP) by eliminating the inhibitory effects of toxic compounds on nitrification.

    Science.gov (United States)

    Han, Yuanyuan; Jin, Xibiao; Wang, Feng; Liu, Yongdi; Chen, Xiurong

    2014-01-01

    During the startup of a full-scale anoxic/aerobic (A/O) biological treatment plant for acrylonitrile wastewater, the removal efficiencies of NH(3)-N and total Kjeldahl nitrogen (TKN) were 1.29 and 0.83% on day 30, respectively. The nitrification process was almost totally inhibited, which was mainly caused by the inhibitory effects of toxic compounds. To eliminate the inhibition, cultivating the bacteria that degrade toxic compounds with patience was applied into the second startup of the biological treatment plant. After 75 days of startup, the inhibitory effects of the toxic compounds on nitrification were eliminated. The treatment plant has been operated stably for more than 3 years. During the last 100 days, the influent concentrations of chemical oxygen demand (COD), NH(3)-N, TKN and total cyanide (TCN) were 831-2,164, 188-516, 306-542 and 1.17-9.57 mg L(-1) respectively, and the effluent concentrations were 257 ± 30.9, 3.30 ± 1.10, 31.6 ± 4.49 and 0.40 ± 0.10 mg L(-1) (n = 100), respectively. Four strains of cyanide-degrading bacteria which were able to grow with cyanide as the sole carbon and nitrogen source were isolated from the full-scale biological treatment plant. They were short and rod-shaped under scanning electron microscopy (SEM) and were identified as Brevundimonas sp., Rhizobium sp., Dietzia natronolimnaea and Microbacterium sp., respectively.

  8. Flame retardancy mechanisms of bisphenol A bis(diphenyl phosphate) in combination with zinc borate in bisphenol A polycarbonate/acrylonitrile-butadiene-styrene blends

    International Nuclear Information System (INIS)

    Pawlowski, Kristin H.; Schartel, Bernhard; Fichera, Mario A.; Jaeger, Christian

    2010-01-01

    Bisphenol A polycarbonate/acrylonitrile-butadiene-styrene (PC/ABS) with and without bisphenol A bis(diphenyl phosphate) (BDP) and 5 wt.% zinc borate (Znb) were investigated. The pyrolysis was studied by thermogravimetry (TG), TG-FTIR and NMR, the fire behaviour with a cone calorimeter applying different heat fluxes, LOI and UL 94. Fire residues were examined with NMR. BDP affects the decomposition of PC/ABS and acts as a flame retardant in the gas and condensed phases. The addition of Znb results in an additional hydrolysis of PC. The fire behaviour is similar to PC/ABS, aside from a slightly increased LOI and a reduced peak heat release rate, both caused by borates improving the barrier properties of the char. In PC/ABS + BDP + Znb, the addition of Znb yields a borate network and amorphous phosphates. Znb also reacts with BDP to form alpha-zinc phosphate and borophosphates that suppress the original flame retardancy mechanisms of BDP. The inorganic-organic residue formed provides more effective flame retardancy, in particular at low irradiation in the cone calorimeter, and a clear synergy in LOI, whereas for more developed fires BDP + Znb become less effective than BDP in PC/ABS with respect to the total heat evolved.

  9. Heat shrinkable behavior, physico-mechanical and structure properties of electron beam cross-linked blends of high-density polyethylene with acrylonitrile-butadiene rubber

    Science.gov (United States)

    Reinholds, Ingars; Kalkis, Valdis; Merijs-Meri, Remo; Zicans, Janis; Grigalovica, Agnese

    2016-03-01

    In this study, heat-shrinkable composites of electron beam irradiated high-density polyethylene (HDPE) composites with acrylonitrile-butadiene rubber (NBR) were investigated. HDPE/NBR blends at a ratio of components 100/0, 90/10, 80/20, 50/50 and 20/80 wt% were prepared using a two-roll mill. The compression molded films were irradiated high-energy (5 MeV) accelerated electrons up to irradiation absorbed doses of 100-300 kGy. The effect of electron beam induced cross-linking was evaluated by the changes of mechanical properties, gel content and by the differences of thermal properties, detected by differential scanning calorimetry. The thermo-shrinkage forces were determined as the kinetics of thermorelaxation and the residual shrinkage stresses of previously oriented (stretched up to 100% at above melting temperature of HDPE and followed by cooling to room temperature) specimens of irradiated HDPE/NBR blends under isometric heating-cooling mode. The compatibility between the both components was enhanced due to the formation of cross-linked sites at amorphous interphase. The results showed increase of mechanical stiffness of composites with increase of irradiation dose. The values of gel fraction compared to thermorelaxation stresses increased with the growth of irradiation dose level, as a result of formation cross-linked sites in amorphous PP/NBR interphase.

  10. Effect of Short PET Fiber and Electron Beam Irradiation on The Properties of Acrylonitrile Butadiene Rubber-Poly(Vinyl Chloride) (NBR-PVC) Blend

    International Nuclear Information System (INIS)

    Youssef, H.A.; Shaltout, N.A.; EI Nemer, K.F.; EI Miligy, A.A.

    2009-01-01

    Blend of acrylonitrile-butadiene rubber (NBR ) and ploy vinyl chloride(PYV) (70-30) has been loaded with different concentrations of polyethylene terephthalate (PET) fibers waste ( 0.5 - 40 p hr); in the presence of resorcinol hexamethylenetetramine - precipitated silica (RHS) as bonding agent system and pentaeritheroal tetraacrylate (PET A) as co agent. Curing of the prepared composites has been carried out by electron beam irradiation (25 - 150 kGy) under atmospheric conditions. Evaluations of mechanical, physical, and thermal properties of uncured as well as cured composites have been undertaken. It has been found that the tensile strength, tensile modulus at 25 % elongation and hardness were increased with irradiation dose as well as fiber loading whereas the elongation at break and soluble fraction were decreased. Moreover, it has been found that the thermal stability of prepared composites at constant fiber loading of 10 p hr is improved on irradiation up to 100 kGy. Confirmation of latter data has been found through calculation of activation energy, Ea of the thermal degradation process

  11. Effect of Short PET Fiber and Electron Beam Irradiation on The Properties of Acrylonitrile Butadiene Rubber-Poly(Vinyl Chloride) (NBR-PVC) Blend

    International Nuclear Information System (INIS)

    Youssef, H.A.; Shaltout, N.A.; EI Nemer, K.F.; EI Miligy, A.A.

    2008-01-01

    Blend of acrylonitrile-butadiene rubber (NBR ) and ploy vinyl chloride(PYV) (70-30) has been loaded with different concentrations of polyethylene terephthalate (PET) fibers waste ( 0.5 - 40 p hr); in the presence of resorcinol hexamethylenetetramine - precipitated silica (RHS) as bonding agent system and pentaeritheroal tetraacrylate (PET A) as co agent. Curing of the prepared composites has been carried out by electron beam irradiation (25 - 150 kGy) under atmospheric conditions. Evaluations of mechanical, physical, and thermal properties of uncured as well as cured composites have been undertaken. It has been found that the tensile strength, tensile modulus at 25 % elongation and hardness were increased with irradiation dose as well as fiber loading whereas the elongation at break and soluble fraction were decreased. Moreover, it has been found that the thermal stability of prepared composites at constant fiber loading of 10 p hr is improved on irradiation up to 100 kGy. Confirmation of latter data has been found through calculation of activation energy, Ea of the thermal degradation process

  12. Evaluation of image uniformity and radiolucency for computed tomography phantom made of 3-dimensional printing of fused deposition modeling technology by using acrylonitrile but audience styrene resin

    International Nuclear Information System (INIS)

    Seoung, Youl Hun

    2016-01-01

    The purpose of this study was to evaluate the radiolucency for the phantom output to the 3D printing technology. The 3D printing technology was applied for FDM (fused deposition modeling) method and was used the material of ABS (acrylonitrile butadiene styrene) resin. The phantom was designed in cylindrical uniformity. An image uniformity was measured by a cross-sectional images of the 3D printed phantom obtained from the CT equipment. The evaluation of radiolucency was measured exposure dose by the inserted ion-chamber from the 3D printed phantom. As a results, the average of uniformity in the cross-sectional CT image was 2.70 HU and the correlation of radiolucency between PMMA CT phantom and 3D printed ABS phantom is found to have a high correlation to 0.976. In the future, this results will be expected to be used as the basis for the phantom production of the radiation quality control by used 3D printing technology

  13. Structure and properties of melt-spun high acrylonitrile copolymer fibers via continuous zone-drawing and zone-annealing processes

    International Nuclear Information System (INIS)

    Wu Zongquan; Zhang Anqiu; Percec, Simona; Jin Shi; Jing, Alexander J.; Ge, Jason J.; Cheng, Stephen Z.D.

    2003-01-01

    Continuous zone-drawing and zone-annealing processes have been utilized to probe improvements in mechanical performance of melt-spun high acrylonitrile copolymer fibers (AMLON TM ). The as-spun fibers were zone-drawn at different ratios in a narrow temperature range of 100-105 deg. C and then zone-annealed. As a result of these processes, the fibers show substantial increases in tensile strength and tensile modulus (about three times) and significant improvements in elongation-at-break (about two times) after zone annealing. The thermal transition behavior, dimensional stability and dynamic relaxation properties of the as-spun, zone-drawn and zone-annealed fibers have been studied using differential scanning calorimetry, thermal mechanical and dynamic mechanical experiments. Their mechanical and thermal property changes after the zone-drawing and zone-annealing processes can be associated with the microscopic structural evolution including crystallinity, crystal orientation and apparent crystallite size detected by wide angle X-ray diffraction experiments

  14. Preparation of a microporous polymer electrolyte based on poly(vinyl chloride)/poly(acrylonitrile-butyl acrylate) blend for Li-ion batteries

    International Nuclear Information System (INIS)

    Tian, Zheng; Pu, Weihua; He, Xiangming; Wan, Chunrong; Jiang, Changyin

    2007-01-01

    Poly(acrylonitrile-co-butyl acrylate) (P(AN-co-BuA))/poly(vinyl chloride) (PVC) blend-based gel polymer electrolyte (BGPE) was prepared for lithium-ion batteries. The P(AN-co-BuA)/PVC BGPE consists of an electrolyte-rich phase, which is mainly composed of P(AN-co-BuA) and liquid electrolyte, acting as a conducting channel and a PVC-rich phase that provides mechanical strength. The dual phase was just simply developed by the difference of miscibility properties in solvent, PC, between P(AN-co-BuA) and PVC. The mechanical strength of this new blend electrolyte was found to be much higher, with a fracture stress as high as 29 MPa in dry membrane and 21 MPa in gel state, than that of a previously reported P(AN-co-BuA)-based gel polymer electrolyte. The blended gel polymer electrolyte showed ionic conductivity of higher than 1.5 x 10 -3 S cm -1 and electrochemical stability up to at least 4.8 V. The results showed that the as-prepared gel polymer electrolytes were promising materials for lithium-ion batteries

  15. Preparation of a microporous polymer electrolyte based on poly(vinyl chloride)/poly(acrylonitrile-butyl acrylate) blend for Li-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Zheng; Pu, Weihua; He, Xiangming; Wan, Chunrong; Jiang, Changyin [Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China)

    2007-02-15

    Poly(acrylonitrile-co-butyl acrylate) (P(AN-co-BuA))/poly(vinyl chloride) (PVC) blend-based gel polymer electrolyte (BGPE) was prepared for lithium-ion batteries. The P(AN-co-BuA)/PVC BGPE consists of an electrolyte-rich phase, which is mainly composed of P(AN-co-BuA) and liquid electrolyte, acting as a conducting channel and a PVC-rich phase that provides mechanical strength. The dual phase was just simply developed by the difference of miscibility properties in solvent, PC, between P(AN-co-BuA) and PVC. The mechanical strength of this new blend electrolyte was found to be much higher, with a fracture stress as high as 29 MPa in dry membrane and 21 MPa in gel state, than that of a previously reported P(AN-co-BuA)-based gel polymer electrolyte. The blended gel polymer electrolyte showed ionic conductivity of higher than 1.5 x 10{sup -3} S cm{sup -1} and electrochemical stability up to at least 4.8 V. The results showed that the as-prepared gel polymer electrolytes were promising materials for lithium-ion batteries. (author)

  16. Effect of polypropylene maleic anhydride (PPMAH) on mechanical and morphological properties of polypropylene (PP)/recycled acrylonitrile butadiene rubber (NBRr)/empty fruit bunch (EFB) composites

    Science.gov (United States)

    Othman, Nurul Syazwani; Santiagoo, Ragunathan; Abdillahi, Khalid Mohamed; Ismail, Hanafi

    2017-07-01

    The fabrication of polypropylene (PP)/ recycled acrylonitrile butadiene rubber (NBRr)/ empty fruit bunch (EFB) composites were investigated. The effects of polypropylene maleic anhydride (PPMAH) as a compatibilizer on the mechanical and morphological properties of PP/NBRr/EFB composites were studied. Composites were prepared through melt mixing using heated two roll mill at 180 °C for 9 minutes and rotor speed of 15 rpm. NBRr loading were varied from 0 to 60 phr and PPMAH was fixed for 5 phr. The composites were moulded into a 1 mm thin sheet using hot press machine and then cut into dumbbell shape. The mechanical and morphological properties of composites were examined using universal tensile machine (UTM) and scanning electron microscope (SEM), respectively. Tensile strength and Young's modulus of PP/NBRr/EFB composites decreased with increasing NBRr loading, whilst increasing the elongation at break. However, PPMAH compatibilized composites have resulted 27% to 40% and 25% to 42% higher tensile strength and Young's modulus, respectively, higher compared to uncompatibilized composites. This was due to the better adhesion between PP/NBRr matrices and EFB filler with the presence of maleic anhydride moieties. From the morphological study, the micrograph of PPMAH compatibilized composites has proved the well bonded and good attachments of EFB filler with PP/NBRr matrices which results better tensile strength to the PP/NBRr/EFB composites.

  17. THE DISSOCIATIVE RECOMBINATION OF PROTONATED ACRYLONITRILE, CH2CHCNH+, WITH IMPLICATIONS FOR THE NITRILE CHEMISTRY IN DARK MOLECULAR CLOUDS AND THE UPPER ATMOSPHERE OF TITAN

    International Nuclear Information System (INIS)

    Vigren, E.; Hamberg, M.; Zhaunerchyk, V.; Kaminska, M.; Thomas, R. D.; Larsson, M.; Geppert, W. D.; Millar, T. J.; Walsh, C.

    2009-01-01

    Measurements on the dissociative recombination (DR) of protonated acrylonitrile, CH 2 CHCNH + , have been performed at the heavy ion storage ring CRYRING located in the Manne Siegbahn Laboratory in Stockholm, Sweden. It has been found that at ∼2 meV relative kinetic energy about 50% of the DR events involve only ruptures of X-H bonds (where X = C or N) while the rest leads to the production of a pair of fragments each containing two heavy atoms (alongside H and/or H 2 ). The absolute DR cross section has been investigated for relative kinetic energies ranging from ∼1 meV to 1 eV. The thermal rate coefficient has been determined to follow the expression k(T) = 1.78 x 10 -6 (T/300) - 0.80 cm 3 s -1 for electron temperatures ranging from ∼10 to 1000 K. Gas-phase models of the nitrile chemistry in the dark molecular cloud TMC-1 have been run and results are compared with observations. Also, implications of the present results for the nitrile chemistry of Titan's upper atmosphere are discussed.

  18. The effects of printing orientation on the electrochemical behaviour of 3D printed acrylonitrile butadiene styrene (ABS)/carbon black electrodes.

    Science.gov (United States)

    Bin Hamzah, Hairul Hisham; Keattch, Oliver; Covill, Derek; Patel, Bhavik Anil

    2018-06-14

    Additive manufacturing also known as 3D printing is being utilised in electrochemistry to reproducibly develop complex geometries with conductive properties. In this study, we explored if the electrochemical behavior of 3D printed acrylonitrile butadiene styrene (ABS)/carbon black electrodes was influenced by printing direction. The electrodes were printed in both horizontal and vertical directions. The horizsontal direction resulted in a smooth surface (HPSS electrode) and a comparatively rougher surface (HPRS electrode) surface. Electrodes were characterized using cyclic voltammetry, electrochemical impedance spectroscopy and chronoamperometry. For various redox couples, the vertical printed (VP) electrode showed enhanced current response when compared the two electrode surfaces generated by horizontal print direction. No differences in the capacitive response was observed, indicating that the conductive surface area of all types of electrodes were identical. The VP electrode had reduced charge transfer resistance and uncompensated solution resistance when compared to the HPSS and HPRS electrodes. Overall, electrodes printed in a vertical direction provide enhanced electrochemical performance and our study indicates that print orientation is a key factor that can be used to enhance sensor performance.

  19. Role of the acid-base properties of gallium-antimony oxide catalyst in oxidative ammonolysis of propane to acrylonitrile (AN)

    Energy Technology Data Exchange (ETDEWEB)

    Osipova, Z.G.; Sokolovskii, V.D.

    1979-07-01

    The role of the acid-base properties of gallium-antimony oxide catalyst in oxidative ammonolysis of propane to acrylonitrile (AN) was studied in a differential flow reactor at 550/sup 0/C, with the reaction mixture containing 5 3< by vol propane, 6 3< ammonia, and 18.6Vertical Bar3< oxygen diluted in helium, over ebulliated beds of a 5Vertical Bar3< Ga/Sb or a 1:3:1.5:1 Ga/Sb/Ni/P catalysts, the basicity of which was varied by adding 5 mole Vertical Bar3< of an alkaline earth metal (added as the nitrate and calcined). Both the rate of propane conversion and that of AN formation increased with increasing concentration of the basic sites (determined by back titration with benzoic acid) on both types of the catalysts and linearly correlated with the amount of nitrous oxide desorbed from the catalysts after the reaction. The presence of ammonia in the reaction mixture increased the activity and selectivity of the catalysts and the concentration of the active basic sites. Apparently, the reaction rate is limited by proton abstraction from a propane molecule with the formation of a carbanion stabilized on alkaline-earth metal cations. The rate-determining proton abstraction occurs on nucleophile basic sites, formed by dissociative adsorption of ammonia to form species such as NH, NH/sub 2/, and HNO, which are then oxidized to N/sub 2/ and N/sub 2/O.

  20. Co-recycling of acrylonitrile-butadiene-styrene waste plastic and nonmetal particles from waste printed circuit boards to manufacture reproduction composites.

    Science.gov (United States)

    Sun, Zhixing; Shen, Zhigang; Zhang, Xiaojing; Ma, Shulin

    2015-01-01

    This study investigated the feasibility of using acrylonitrile-butadiene-styrene (ABS) waste plastic and nonmetal particles from waste printed circuit boards (WPCB) to manufacture reproduction composites (RC), with the aim of co-recycling these two waste resources. The composites were prepared in a twin-crew extruder and investigated by means of mechanical testing, in situ flexural observation, thermogravimatric analysis, and dimensional stability evaluation. The results showed that the presence of nonmetal particles significantly improved the mechanical properties and the physical performance of the RC. A loading of 30 wt% nonmetal particles could achieve a flexural strength of 72.6 MPa, a flexural modulus of 3.57 GPa, and an impact strength of 15.5 kJ/m2. Moreover, it was found that the application of maleic anhydride-grafted ABS as compatilizer could effectively promote the interfacial adhesion between the ABS plastic and the nonmetal particles. This research provides a novel method to reuse waste ABS and WPCB nonmetals for manufacturing high value-added product, which represents a promising way for waste recycling and resolving the environmental problem.

  1. Enhancing mechanical and thermal properties of styrene-butadiene rubber/carboxylated acrylonitrile butadiene rubber blend by the usage of graphene oxide with diverse oxidation degrees

    Science.gov (United States)

    Xue, Xiaodong; Yin, Qing; Jia, Hongbing; Zhang, Xuming; Wen, Yanwei; Ji, Qingmin; Xu, Zhaodong

    2017-11-01

    Graphene oxide (GO) with various oxidation degrees were prepared through a modified Hummer's method by varying the dosage of oxidizing agent. Styrene-butadiene rubber (SBR)/carboxylated acrylonitrile butadiene rubber (XNBR)/GO nanocomposites were fabricated by aqueous-phase mixing of GO colloidal dispersion with SBR latex and a small loading of XNBR latex, followed by co-coagulation. Effects of GO oxidation degree on the morphology, structure, mechanical and thermal properties of nanocomposites were thoroughly investigated. The results showed that the mechanical strength of nanocomposites were enhanced with the increase of oxidation degree of GO. Especially, when the weight ratio of KMnO4 to graphite was 15/5, the tensile strength, tear strength and thermal conductivity of SBR/XNBR/GO filled with 3 phr (parts per hundred rubber) GO increased by 255.3%, 141.5% and 22.8%, respectively, compared to those of neat SBR/XNBR blend. In addition, the thermal stability and the solvent resistance of the nanocomposites were also improved significantly. This work suggested that GO with higher oxidation degree could effectively improve the properties of SBR/XNBR blend.

  2. Effects of content and surface hydrophobic modification of BaTiO3 on the cooling properties of ASA (acrylonitrile-styrene-acrylate copolymer)

    Science.gov (United States)

    Xiang, Bo; Zhang, Jun

    2018-01-01

    For the field of cool material, barium titanate (BaTiO3, BT) is still a new member that needs to be further studied. Herein, the effects of both content and surface hydrophobic modification of BT on the cooling properties of acrylonitrile-styrene-acrylate copolymer (ASA) were detailedly investigated, aiming to fabricate composited cool material. Butyl acrylate (BA) was employed to convert the surface of BT from hydrophilic to hydrophobic. The addition of unmodified BT could significantly improve the solar reflectance of ASA, especially when the addition amount is 3 vol%, the near infrared (NIR) reflectance increased from 22.02 to 72.60%. However, serious agglomeration occurred when the addition amount increased to 5 vol% and therefore led to a relatively smaller increase in solar reflectance and an obvious decline in impact strength. After surface hydrophobic modification, the modified BT (M-BT) presented better dispersibility in ASA matrix, which contributed to the improvement of both solar reflectance and impact strength. In addition, the temperature test provided a more sufficient and intuitive way to evaluate the cooling effect of the composited cool materials, and a significant decrease (over 10 °C) could be achieved in the temperature test when M-BT particles were introduced.

  3. Three-dimensional Printed Acrylonitrile Butadiene Styrene Framework Coated with Cu-BTC Metal-organic Frameworks for the Removal of Methylene Blue

    Science.gov (United States)

    Wang, Zongyuan; Wang, Jiajun; Li, Minyue; Sun, Kaihang; Liu, Chang-jun

    2014-01-01

    Three-dimensional (3D) printing was applied for the fabrication of acrylonitrile butadiene styrene (ABS) framework. Functionalization of the ABS framework was then performed by coating of porous Cu-BTC (BTC = benzene tricarboxylic acid) metal-organic frameworks on it using a step-by-step in-situ growth. The size of the Cu-BTC particles on ABS was ranged from 200 nm to 900 nm. The Cu-BTC/ABS framework can take up most of the space of the tubular reactor that makes the adsorption effective with no need of stirring. Methylene blue (MB) can be readily removed from aqueous solution by this Cu-BTC/ABS framework. The MB removal efficiency for solutions with concentrations of 10 and 5 mg/L was 93.3% and 98.3%, respectively, within 10 min. After MB adsorption, the Cu-BTC/ABS composite can easily be recovered without the need for centrifugation or filtration and the composite is reusable. In addition the ABS framework can be recovered for subsequent reuse. A significant advantage of 3D-printed frameworks is that different frameworks can be easily fabricated to meet the needs of different applications. This is a promising strategy to synthesize new frameworks using MOFs and polymers to develop materials for applications beyond adsorption. PMID:25089616

  4. Hydrophobic surface modification of TiO2 nanoparticles for production of acrylonitrile-styrene-acrylate terpolymer/TiO2 composited cool materials

    Science.gov (United States)

    Qi, Yanli; Xiang, Bo; Tan, Wubin; Zhang, Jun

    2017-10-01

    Hydrophobic surface modification of TiO2 was conducted for production of acrylonitrile-styrene-acrylate (ASA) terpolymer/titanium dioxide (TiO2) composited cool materials. Different amount of 3-methacryloxypropyl-trimethoxysilane (MPS) was employed to change hydrophilic surface of TiO2 into hydrophobic surface. The hydrophobic organosilane chains were successfully grafted onto TiO2 through Sisbnd Osbnd Ti bonds, which were verified by Fourier transformed infrared spectra and X-ray photoelectron spectroscopy. The water contact angle of the sample added with TiO2 modified by 5 wt% MPS increased from 86° to 113°. Besides, all the ASA/TiO2 composites showed significant improvement in both solar reflectance and cooling property. The reflectance of the composites throughout the near infrared (NIR) region and the whole solar wavelength is increased by 113.92% and 43.35% compared with pristine ASA resin. Simultaneously, significant drop in temperature demonstrates excellent cooling property. A maximum decrease approach to 27 °C was observed in indoor temperature test, while a decrease around 9 °C tested outdoors is achieved.

  5. A facile method of hydrophobic surface modification for acrylonitrile-styrene-acrylate terpolymer based on the out-migration property of metallic soaps

    Science.gov (United States)

    Qi, Yanli; Chen, Tingting; Zhang, Jun

    2018-03-01

    Hydrophobic surface modification is conducted in this study by using additives with long alkyl chains. Several kinds of metallic soaps, such as calcium stearate (CaSt), zinc stearate (ZnSt), magnesium stearate (MgSt) and barium stearate (BaSt) were employed. Polymer matrix is acrylonitrile-styrene-acrylate (ASA) terpolymer due to its wonderful weather resistance property. The surface chemical characterization was studied by Fourier transformed infrared (FTIR) technology and X-ray photoelectron spectroscopy (XPS). Carboxylate (Osbnd Csbnd O-) indexes of composites in both transmittance and reflection modes were calculated according to FTIR results. As to the ratio of carboxylate index in reflection mode to that in transmittance mode, the sample added with 5 wt% ZnSt shows a higher value of 8.77, and a much higher value of 14.47 for the sample added with 10 wt% ZnSt. The corresponding Csbnd C/ Csbnd H /Cdbnd C peak areas of the samples added with 5 wt% or 10 wt% ZnSt are 75.4% and 77.3% respectively, much higher than other samples. This indicates ZnSt is much easier to out-migrate to material surface and therefore is more suitable for hydrophobic surface modification. In particular, the water contact angle of the ASA/ZnSt composite added with 10 wt% ZnSt significantly increased to 127o (40o increase in comparison with pure ASA), successfully converting the surface wettability from hydrophilic to hydrophobic.

  6. Triazolopyridinyl-acrylonitrile derivatives as antimicrotubule agents: Synthesis, in vitro and in silico characterization of antiproliferative activity, inhibition of tubulin polymerization and binding thermodynamics.

    Science.gov (United States)

    Briguglio, Irene; Laurini, Erik; Pirisi, Maria Antonietta; Piras, Sandra; Corona, Paola; Fermeglia, Maurizio; Pricl, Sabrina; Carta, Antonio

    2017-12-01

    In this paper we report the synthesis, in vitro anticancer activity, and the experimental/computational characterization of mechanism of action of a new series of E isomers of triazolo[4,5-b/c]pyridin-acrylonitrile derivatives (6c-g, 7d-e, 8d-e, 9c-f, 10d-e, 11d-e). All new compounds are endowed with moderate to interesting antiproliferative activity against 9 different cancer cell lines derived from solid and hematological human tumors. Fluorescence-based assays prove that these molecules interfere with tubulin polymerization. Furthermore, isothermal titration calorimetry (ITC) provides full tubulin/compound binding thermodynamics, thereby ultimately qualifying and quantifying the interactions of these molecular series with the target protein. Lastly, the analysis based on the tight coupling of in vitro and in silico modeling of the interactions between tubulin and the title compounds allows to propose a molecular rationale for their biological activity. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  7. Microwave absorption properties of lightweight absorber based on Fe{sub 50}Ni{sub 50}-coated poly(acrylonitrile) microspheres and reduced graphene oxide composites

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Bin [School of Material Science And Engineering, Wuhan University of Technology, Wuhan 430070 (China); Wang, Jun, E-mail: wgdfrp@whut.edu.cn [School of Material Science And Engineering, Wuhan University of Technology, Wuhan 430070 (China); Wang, Junpeng; Huo, Siqi [School of Material Science And Engineering, Wuhan University of Technology, Wuhan 430070 (China); Zhang, Bin [School of Science, Wuhan University of Technology, Wuhan 430070 (China); Tang, Yushan [School of Material Science And Engineering, Wuhan University of Technology, Wuhan 430070 (China)

    2016-09-01

    In this paper, we proposed a facile method to obtain the lightweight composites consisting of surface modified Fe{sub 50}Ni{sub 50}-coated poly(acrylonitrile) microspheres (PANS@SMF), reduced graphene oxide (RGO) and epoxy resin. The as-prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), vibrating sample magnetometry (VSM) and vector network analyzer (VNA). Impedance matching condition and electromagnetic wave attenuation characteristic were used for the reflection loss (RL) performance of the composites. Compared with pure PANS@SMF and RGO composites, the −10 dB absorption bandwidth and the minimum RL of the hybrid composites were enhanced. The bandwidth less than −10 dB was almost 4.5 GHz in the range of 10 GHz to 14.5 GHz, with a matching thickness of 2.5 mm. The density of the hybrid composites was in the range of 0.25–0.34 g/cm{sup 3}. Therefore, the hybrid composite can be considered as a potential lightweight microwave absorber. - Highlights: • PANS@SMF – RGO epoxy composite was fabricated by a facile method. • The absorption bandwidth less than −10 dB can reach up to 4.5 GHz with layer thickness of 2.5 mm. • The density of the composites is in the range of 0.25–0.34 g/cm{sup 3} and can be considered as a lightweight microwave absorber.

  8. Investigation of the effect of nanoclay and processing parameters on the tensile strength and hardness of injection molded Acrylonitrile Butadiene Styrene–organoclay nanocomposites

    International Nuclear Information System (INIS)

    Mamaghani Shishavan, Sajjad; Azdast, Taher; Rash Ahmadi, Samrand

    2014-01-01

    Highlights: • Development of polymer/clay nanocomposites. • Compatibility of ABS and montmorillonite nanoclay and composition capability of them. • Effect of nanoclay content and process parameters on the mechanical properties of nanocomposite. • Analyzing the distribution of nanoclay layers using XRD test. • Dependency of tensile strength and hardness to the nanoclay content and processing conditions. - Abstract: Polymer–clay nanocomposites have attracted considerable interest over recent years due to their dramatic improved mechanical properties. In the present study, compatibility of Acrylonitrile Butadiene Styrene (ABS) and organically modified montmorillonite nanoclay (Cloisite 30B) and composition capability of them are investigated. Polymethylmethacrylate (PMMA) in varying amount (0, 2, and 4 wt%) is used as the compatibilizer. In order to produce nanocomposite parts, the material is first compounded using a twin-screw extruder and then injected into a mold. The effect of the nanoclay percentage and processing parameters on the tensile strength and hardness of nanocomposite parts is also explored using Taguchi Design of Experiments method. Nanoclay content (in three levels: 0, 2 and 4 wt%), melt temperature (in three levels: 190, 200 and 210 °C), holding pressure (in three levels: 80, 105 and 130 MPa) and holding pressure time (in three levels: 1, 2.5 and 4 s) are considered as the variable parameters. Moreover, distribution of nanoclay layers is analyzed using Wide Angle X-ray Diffraction (XRD) test. XRD results displayed that with the presence of PMMA, nanoclay in ABS matrix is compounded in more exfoliated and less intercalated dispersion mode. Adding PMMA also leads to a remarkable increase in the fluidity of the melt during injection molding process. Results also illustrated that nanocomposites with medium loading level (i.e. 2%) of nanoclay have the highest tensile strength, while the highest hardness number belongs to nanocomposites with

  9. Heat shrinkable behavior, physico-mechanical and structure properties of electron beam cross-linked blends of high-density polyethylene with acrylonitrile-butadiene rubber

    International Nuclear Information System (INIS)

    Reinholds, Ingars; Kalkis, Valdis; Merijs-Meri, Remo; Zicans, Janis; Grigalovica, Agnese

    2016-01-01

    In this study, heat-shrinkable composites of electron beam irradiated high-density polyethylene (HDPE) composites with acrylonitrile-butadiene rubber (NBR) were investigated. HDPE/NBR blends at a ratio of components 100/0, 90/10, 80/20, 50/50 and 20/80 wt% were prepared using a two-roll mill. The compression molded films were irradiated high-energy (5 MeV) accelerated electrons up to irradiation absorbed doses of 100–300 kGy. The effect of electron beam induced cross-linking was evaluated by the changes of mechanical properties, gel content and by the differences of thermal properties, detected by differential scanning calorimetry. The thermo-shrinkage forces were determined as the kinetics of thermorelaxation and the residual shrinkage stresses of previously oriented (stretched up to 100% at above melting temperature of HDPE and followed by cooling to room temperature) specimens of irradiated HDPE/NBR blends under isometric heating–cooling mode. The compatibility between the both components was enhanced due to the formation of cross-linked sites at amorphous interphase. The results showed increase of mechanical stiffness of composites with increase of irradiation dose. The values of gel fraction compared to thermorelaxation stresses increased with the growth of irradiation dose level, as a result of formation cross-linked sites in amorphous PP/NBR interphase. - Highlights: • Binary blends of HDPE/NBR have been irradiated with 5 MeV accelerated electrons. • Increase of NBR content and irradiation dose improves cross-linking efficiency. • Thermo-shrinkage and residual stresses are investigated for oriented specimens. • Cross-linked HDPE/NBR composites can be successfully used as thermos-shrinkable materials.

  10. Largely improved the low temperature toughness of acrylonitrile-styrene-acrylate (ASA) resin: Fabricated a core-shell structure of two elastomers through the differences of interfacial tensions

    Science.gov (United States)

    Mao, Zepeng; Zhang, Jun

    2018-06-01

    The phase morphology of two elastomers (i.e., chlorinated polyethylene (CPE) and polybutadiene rubber (BR)) were devised to be a core-shell structure in acrylonitrile-styrene-acrylate (ASA) resin matrix, via the interfacial tension differences of polymer pairs. Selective extraction test and scanning electron microscopy (SEM) were utilized to verify this special phase morphology. The results demonstrated that the core-shell structure, BR core and CPE shell, significantly contributed to improve the low temperature toughness of ASA/CPE/BR ternary blends, which may be because the nonpolar BR core was segregated from polar ASA by the CPE shell. The CPE shell served dual functions: Not only did it play compatibilizing effect in the interface between BR and ASA matrix, but it also toughened the blends at 25 and 0 °C. The blends of ASA/CPE/BR (100/27/3, w/w/w) and ASA/CPE/BR (100/22/8, w/w/w) showed the peak impact strengths at about 28 and 9 kJ/m2 at 0 and -30 °C, respectively, which were higher than both that of ASA/CPE/BR (100/30/0, w/w/w) and ASA/CPE/BR (100/0/30, w/w/w). Moreover, the impact strength of ternary blends at room temperature kept at 40 kJ/m2 when BR content was lower than 10 phr. Other characterizations including contact angle measurement, dynamic mechanical thermal analysis (DMTA), morphology of impact-fractured surfaces, tensile properties, flexural properties, and Fourier transform infrared spectroscopy (FTIR) were measured as well.

  11. Compliant gel polymer electrolyte based on poly(methyl acrylate-co-acrylonitrile)/poly(vinyl alcohol) for flexible lithium-ion batteries

    International Nuclear Information System (INIS)

    Ma, Xianguo; Huang, Xinglan; Gao, Jiandong; Zhang, Shu; Deng, Zhenghua; Suo, Jishuan

    2014-01-01

    Highlights: •Compliant gel polymer electrolyte based on P(MA-co-AN)/PVA is facilely prepared for flexible lithium-ion batteries. •The compliant gel polymer electrolyte displays high ionic conductivity, self-standing and mechanical flexible. •The compliant gel polymer electrolyte exhibits excellent chemical and electrochemical performances. -- Abstract: In this report, mechanically compliant gel polymer electrolyte (GPE) for flexible lithium-ion batteries is facilely fabricated. The GPE that based on the poly(methyl acrylate-co-acrylonitrile)/poly(vinyl alcohol) (P(MA-co-AN)/PVA) was prepared via emulsion polymerization. Herein, the P(MA-co-AN) copolymer is anticipated to exert beneficial for the bendability of the GPE, as well as swollen with the liquid electrolyte to provide a facile pathway for ion movement. The PVA serves as a stabilizer during the emulsion polymerization and a mechanical framework for the compliant polymer membrane. Performance benefits of the mechanically compliant membrane are elucidated in terms of mechanical behavior, thermostability and ionic conductivity. The GPE is still self-standing and mechanical flexible after swollen with liquid electrolyte. The GPE displays a conductivity of 0.98 mS cm −1 with the uptake electrolyte up to 150% of its own weight at 30 °C, excellent electrochemical stability window (5.2 V vs. Li/Li + ) and favorable interfacial characteristics. When used in flexible lithium-ion batteries, such a GPE demonstrates satisfactory compatibility with LiCoO 2 and graphite electrodes

  12. Differential metabolism of acrylonitrile to cyanide is responsible for the greater sensitivity of male vs female mice: role of CYP2E1 and epoxide hydrolases

    International Nuclear Information System (INIS)

    Chanas, Brian; Wang, Hongbing; Ghanayem, Burhan I.

    2003-01-01

    Acrylonitrile (AN) is a potent toxicant and a known rodent carcinogen. AN epoxidation to cyanoethylene oxide (CEO) via CYP2E1 and its subsequent metabolism via epoxide hydrolases (EH) to yield cyanide is thought to be responsible for the acute toxicity and mortality of AN. Recent reports showed that male mice are more sensitive than females to the acute toxicity/mortality of AN. The present work was undertaken to assess the metabolic and enzymatic basis for the greater sensitivity of male vs female mice to AN toxicity. Male and female wild-type and CYP2E1-null mice received AN at 0, 2.5, 10, 20, or 40 mg/kg by gavage. Cyanide concentrations were measured at 1 or 3 h after dosing. Current data demonstrated that cyanide levels in blood and tissues of AN-treated wild-type mice of both sexes were significantly greater than in vehicle-treated controls and increased in a dose-dependent manner. In contrast, cyanide levels in AN-treated CYP2E1-null mice were not statistically different from those measured in vehicle-treated controls. Furthermore, higher levels of cyanide were detected in male wild-type mice vs females in association with greater sensitivity of males to the acute toxicity/mortality of this chemical. Using Western blot analysis, negligible difference in CYP2E1 expression with higher levels of soluble and microsomal EH (sEH and mEH) was detected in the liver of male vs female mice. In kidneys, male mice exhibited higher expression of both renal CYP2E1 and sEH than did female mice. In conclusion, higher blood and tissue cyanide levels are responsible for the greater sensitivity of male vs female mice to AN. Further, higher expression of CYP2E1 and EH in male mice may contribute to greater formation of CEO and its subsequent metabolism to yield cyanide, respectively

  13. Comparative acute toxicity of leachates from plastic products made of polypropylene, polyethylene, PVC, acrylonitrile-butadiene-styrene, and epoxy to Daphnia magna.

    Science.gov (United States)

    Lithner, Delilah; Nordensvan, Ildikó; Dave, Göran

    2012-06-01

    The large global production of plastics and their presence everywhere in the society and the environment create a need for assessing chemical hazards and risks associated with plastic products. The aims of this study were to determine and compare the toxicity of leachates from plastic products made of five plastics types and to identify the class of compounds that is causing the toxicity. Selected plastic types were those with the largest global annual production, that is, polypropylene, polyethylene, and polyvinyl chloride (PVC), or those composed of hazardous monomers (e.g., PVC, acrylonitrile-butadiene-styrene [ABS], and epoxy). Altogether 26 plastic products were leached in deionized water (3 days at 50°C), and the water phases were tested for acute toxicity to Daphnia magna. Initial Toxicity Identification Evaluations (C18 filtration and EDTA addition) were performed on six leachates. For eleven leachates (42%) 48-h EC50s (i.e the concentration that causes effect in 50 percent of the test organisms) were below the highest test concentration, 250 g plastic/L. All leachates from plasticized PVC (5/5) and epoxy (5/5) products were toxic (48-h EC50s ranging from 2 to 235 g plastic/L). None of the leachates from polypropylene (5/5), ABS (5/5), and rigid PVC (1/1) products showed toxicity, but one of the five tested HDPE leachates was toxic (48-h EC50 17-24 g plastic/L). Toxicity Identification Evaluations indicated that mainly hydrophobic organics were causing the toxicity and that metals were the main cause for one leachate (metal release was also confirmed by chemical analysis). Toxic chemicals leached even during the short-term leaching in water, mainly from plasticized PVC and epoxy products.

  14. Surface hydrophilic modification of acrylonitrile-butadiene-styrene terpolymer by poly(ethylene glycol-co-1,4-cyclohexanedimethanol terephthalate): Preparation, characterization, and properties studies

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Tingting; Zhang, Jun, E-mail: zhangjun@njtech.edu.cn

    2016-12-01

    Highlights: • Surface hydrophilic modified ABS was prepared by melt blending with PETG. • O= C−O groups were enriched on the surface with increasing PETG content. • Hydrophilic property of the blends was enhanced with increasing PETG content. • Phase inversion behavior of the blends occurred around intermediate composition. • Tensile and flexural strength were enhanced with increasing PETG content. - Abstract: Surface hydrophilic modified acrylonitrile-butadiene-styrene (ABS) terpolymer was prepared by melt blending with poly(ethylene glycol-co-1,4-cyclohexanedimethanol terephthalate) (PETG) random copolymer as the modifier. Attenuated total reflectance-Fourier transform-infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS) were used for surface analysis. Through the contact angle measurement, the relationship between surface properties of the ABS/PETG blends and PETG content was investigated. Scanning electron microscope (SEM) and dynamical mechanical thermal analysis (DMTA) were used to characterize interface morphology and compatibility of the blends. The effect of PETG content on the mechanical and rheological properties was examined. The ATR-FTIR and XPS analysis suggested that the hydrophilic groups were enriched on the surface with increasing PETG content in the blend. The decrease of the water contact angle and the increase of the polarity for the blends with increasing PETG content indicated that the hydrophilic property of the blends was enhanced with increasing PETG content. The ABS/PETG blends were partially miscible. And the blends with ≤50 wt% PETG had better compatibility than the blends with above 50 wt% PETG. It was clear that below 50 wt% PETG, the PETG phase was dispersed in spherical form and the ABS phase was continuous. Above 50 wt% PETG, the PETG phase became continuous and the ABS phase was dispersed in irregular form. Moreover, the tensile strength and flexural strength of the blends were enhanced with

  15. Structural characterization of hydrogen separating membranes based on lanthanide-tungstates; Strukturelle Charakterisierung von Wasserstoff trennenden Gasseparationsmembranen auf Lanthanoid-Wolframat-Basis

    Energy Technology Data Exchange (ETDEWEB)

    Scherb, Tobias

    2011-08-26

    The global energy supply is currently the most controversial issue discussed in our society. Despite the increasing importance of renewable energies, the largest portion of electrical energy has its origin in fossil fuels. CO{sub 2}, emitted during combustion in power plants is known to be one of the greenhouse gases that contributes significantly to global climate change. The development of technologies for environmentally friendly power generation from coal and gas is an area of significant interest. One possibility is the capture and long-term storage of CO{sub 2} from the exhaust stream of fossil fuel power plants. In the pre-combustion process, CO{sub 2} and H{sub 2} can be separated after gasification of the fossil fuel. For this purpose gas-tight ceramic membranes with mixed electronic-protonic conductivity can be used. However, these materials have high requirements due to the extreme conditions in power plants. Mixed electronic-protonic conducting lanthanide tungstates (Ln{sub 6}WO{sub 12} Ln = lanthanide or yttrium) are promising materials, which are stable in CO{sub 2}-containing harsh environments. This work presents a study on structure-property relationships of Ln{sub 6}WO{sub 12}. The structural analysis was performed by the use of neutron and high-resolution X-ray diffraction methods for three exemplary systems (Ln = La, Nd, Y). Samples were prepared via solid state reaction (SSR), and also via a sol-gel approach (Pechini). For the systems LaWO and NdWO, new structural models were developed by combined Rietveld analysis and Fourier density maps. The latter was applied to determine the electron and nuclear density distribution. LaWO with a La/W ratio from 5.3 to 5.7 crystallizes with the space group F-43m and forms a superstructure due to a partially ordered arrangement of cations. On Wyckoff site 48h, up to 4.6 % W can be substituted by La. The oxygen atoms around tungsten are highly delocalized and 6 out of 24 possible split positions are occupied

  16. Fabrication of conducting composite sheets using cost-effective graphite flakes and amorphous styrene acrylonitrile for enhanced thermistor, dielectric, and electromagnetic interference shielding properties

    Energy Technology Data Exchange (ETDEWEB)

    Panwar, Varij, E-mail: varijpanwarcertain@gmail.com [Electronics and Communication Engineering, Graphic Era University, Dehradun, Uttarakhand (India); Gill, Fateh Singh; Rathi, Vikas; Tewari, V.K. [Electronics and Communication Engineering, Graphic Era University, Dehradun, Uttarakhand (India); Mehra, R.M. [Sharda University, Greater Noida (India); Park, Jong-Oh, E-mail: jop@jnu.ac.kr [School of Mechanical Engineering, Chonnam National University, Gwangju (Korea, Republic of); Park, Sukho, E-mail: shpark12@dgist.ac.kr [Department of Robotics Engineering, Daegu Gyeongbuk Institute of Science and Technology, Daegu (Korea, Republic of)

    2017-06-01

    The fabrication of strong conducting composite sheets (CCSs) using a simple technique with cost-effective materials is desirable for capacitor, decoupling capacitor, and electromagnetic interference (EMI) shielding applications. Here, we used cost-effective graphite flakes (GFs) as a conducting filler and amorphous poly (styrene-co-acrylonitrile) (PSAN) as an insulating polymer to fabricate a CCS via a simple mechanical mixing and hot compression molding process in 2.5 h, with the aim to save time and avoid the use of toxic reagents, which are generally used in chemical methods. In the present method, the GFs are connected in diffusively adhere polymer matrix, controlled by temperature and pressure that generate the conduction in the CCSs. The resulting PSAN/GF CCSs were characterized by using scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and hardness tests. The GFs penetrated the interfacial region of PSAN, thus improving the thermistor and dielectric properties (dielectric constant, AC conductivity, and dissipation factor) of the PSAN/GF CCSs. Furthermore, the PSAN/GF CCSs showed enhanced hardness and EMI shielding effectiveness (SE) properties in the X-band frequency range (8.5–12.5 GHz). The percolation theory was implemented to DC and AC conductivity. To detect the transition of the dielectric properties, the dielectric constant of the CCSs was analyzed with increasing volume fraction of GFs in the radio frequency region. The improved dielectric constant, AC conductivity, and dissipation factor of the PSAN/GF CCS, indicated a significant improvement in their EMI shielding properties in the X-band frequency range, which were measured using the waveguide method. The ac conductivity of PSAN/GF CCS shows stable behavior in the higher frequency ranges. The EMISE of PSAN/GF CCS were found to increase with increasing GF content due to the absorbance mechanism. - Highlights: • Enhanced hardness and

  17. Comparative metabolism of methacrylonitrile and acrylonitrile to cyanide using cytochrome P4502E1 and microsomal epoxide hydrolase-null mice

    International Nuclear Information System (INIS)

    El Hadri, L.; Chanas, B.; Ghanayem, B.I.

    2005-01-01

    Methacrylonitrile (MAN) and acrylonitrile (AN) are metabolized via glutathione (GSH) conjugation or epoxide formation. We have recently shown that CYP2E1 is essential for AN epoxidation and subsequent cyanide liberation. Current studies were designed to compare the enzymatic basis of MAN vs. AN metabolism to cyanide using wild-type (WT), CYP2E1-, and mEH-null mice. Mice received a single gavage dose of 0.047, 0.095, 0.19, or 0.38 mmol/kg of MAN or AN, and blood cyanide was measured at 1 or 3 h later. Blood cyanide levels in WT mice treated with AN or MAN were dose and time dependent. At equimolar doses, significantly higher levels of cyanide were detected in the blood of MAN- vs. AN-treated mice. Further, while significant reduction in blood cyanide levels occurred in MAN-treated CYP2E1-null vs. WT mice, AN metabolism to cyanide was largely abolished in CYP2E1-null mice. Pretreatment of mice with 1-aminobenzotriazole (ABT, CYP inhibitor) demonstrated that CYPs other than CYP2E1 also contribute to MAN metabolism to cyanide. Blood cyanide levels in mEH-null mice treated with aliphatic nitriles are generally lower than levels in similarly treated WT mice. Western blot analysis showed that expression of sEH was greater in male vs. female mice. The role of various epoxide hydrolases (EHs) in the production of cyanide from aliphatic nitriles is apparently structure and dose dependent. Regardless of genotype, significantly higher levels of cyanide were measured in the blood of male vs. female mice treated with MAN or AN. In conclusion, these data showed that (1) at equimolar doses, higher blood cyanide levels were detected in mice treated with MAN vs. AN; (2) while CYP2E1 is the only enzyme responsible for AN metabolism to cyanide, other CYPs also contribute to MAN metabolism; and (3) significantly higher levels of cyanide were measured in the blood of male vs. female treated with either nitrile. Higher blood cyanide levels in male vs. female mice and in MAN- vs. AN

  18. Novel synthesis of magnesium hydroxide nanoparticles modified with organic phosphate and their effect on the flammability of acrylonitrile-butadiene styrene nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Attia, Nour F., E-mail: drnour2005@yahoo.com [Fire Protection Laboratory, Chemistry Division, National Institute of Standards, 136, Giza 12211 (Egypt); Goda, Emad S.; Nour, M.A. [Fire Protection Laboratory, Chemistry Division, National Institute of Standards, 136, Giza 12211 (Egypt); Sabaa, M.W. [Chemistry Department, Faculty of Science, Cairo University, NahdetMisr Street, Giza 12613 (Egypt); Hassan, M.A., E-mail: Mohamed_a_hassan@hotmail.com [Fire Protection Laboratory, Chemistry Division, National Institute of Standards, 136, Giza 12211 (Egypt)

    2015-11-15

    New and facile method for the synthesis and modification of magnesium hydroxide nanoparticles has been developed. The organic phosphate was used to facilitate the synthesis and wrapping of magnesium hydroxide nanoparticles with organic phosphate shell. The size of the nanoparticles wrapped with phosphate has an average diameter range from 46 to 125 nm. The preparation method has governed the nanoparticles diameter based on reaction time. Thermal stability and morphological properties of the new nanoparticles coated phosphates were investigated. The developed magnesium hydroxide nanoparticles-organic phosphate achieved a very good compatibility when dispersed in acrylonitrile-butadiene styrene polymer (ABS) produced dispersed nanocomposites. The flammability and thermal properties of the new polymer nanocomposites were studied. The rate of burning of the nanocomposites was reduced to 9.8 mm/min compared to 15, 21.9 and 42.5 mm/min for polymer-conventional magnesium hydroxide composite, polymer-conventional magnesium hydroxide-organic phosphate composite and virgin polymer, respectively. The peak heat release rate (PHRR) and total heat release (THR) of the new nanocomposites were recorded as 243.4 kW/m{sup 2} and 19.2 MJ/m{sup 2}, respectively, achieved 71% reduction for PHRR and 55% for THR. The synergism between magnesium hydroxide nanoparticles and organic phosphates shell was also studied. The developed nanoparticles suppressed the emission of toxic gases. The different materials were characterized using thermal gravimetric analysis, fourier transform infrared spectroscopy, transmission electron microscopy. The flammability properties were evaluated using UL94 horizontal method and cone calorimeter. The dispersion of magnesium hydroxide nanoparticles-organic phosphate in ABS was studied using scanning electron microscope. - Highlights: • Novel and facile nanoparticles synthesis and modification have developed. • Magnesium hydroxide nanoparticles size has

  19. Electrochemical Properties of the LiNi0.6Co0.2Mn0.2O2 Cathode Material Modified by Lithium Tungstate under High Voltage.

    Science.gov (United States)

    Fu, Jiale; Mu, Daobin; Wu, Borong; Bi, Jiaying; Cui, Hui; Yang, Hao; Wu, Hanfeng; Wu, Feng

    2018-05-31

    An amount (5 wt %) of lithium tungstate (Li 2 WO 4 ) as an additive significantly improves the cycle and rate performances of the LiNi 0.6 Co 0.2 Mn 0.2 O 2 electrode at the cutoff voltage of 4.6 V. The 5 wt % Li 2 WO 4 -mixed LiNi 0.6 Co 0.2 Mn 0.2 O 2 electrode delivers a reversible capacity of 199.2 mA h g -1 and keeps 73.1% capacity for 200 cycles at 1 C. It retains 67.4% capacity after 200 cycles at 2 C and delivers a discharge capacity of 167.3 mA h g -1 at 10 C, while those of the pristine electrode are only 44.7% and 87.5 mA h g -1 , respectively. It is shown that the structure of the LiNi 0.6 Co 0.2 Mn 0.2 O 2 cathode material is not affected by mixing Li 2 WO 4 . The introduced Li 2 WO 4 effectively restrains the LiPF 6 and carbonate solvent decomposition by consuming PF 5 at high cutoff voltage, forming a stable cathode/electrolyte interface film with low resistance.

  20. Use of laser-induced breakdown spectroscopy for the determination of polycarbonate (PC) and acrylonitrile-butadiene-styrene (ABS) concentrations in PC/ABS plastics from e-waste.

    Science.gov (United States)

    Costa, Vinicius Câmara; Aquino, Francisco Wendel Batista; Paranhos, Caio Marcio; Pereira-Filho, Edenir Rodrigues

    2017-12-01

    Due to the continual increase in waste generated from electronic devices, the management of plastics, which represents between 10 and 30% by weight of waste electrical and electronic equipment (WEEE or e-waste), becomes indispensable in terms of environmental and economic impacts. Considering the importance of acrylonitrile-butadiene-styrene (ABS), polycarbonate (PC), and their blends in the electronics and other industries, this study presents a new application of laser-induced breakdown spectroscopy (LIBS) for the fast and direct determination of PC and ABS concentrations in blends of these plastics obtained from samples of e-waste. From the LIBS spectra acquired for the PC/ABS blend, multivariate calibration models were built using partial least squares (PLS) regression. In general, it was possible to infer that the relative errors between the theoretical or reference and predicted values for the spiked samples were lower than 10%. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. 防辐射超细钨酸铅的制备及其手套对Y射线屏蔽的研究%Study on Preparation of Ultrafine Lead Tungstate for Radiation Protection and T-ray Shielding of the Gloves

    Institute of Scientific and Technical Information of China (English)

    杜利成; 何平; 周元林; 宋开平; 杨葵华

    2012-01-01

    Lead tungstate combines the radiation shielding properties of tungsten and lead, and it is quite distinctive to manufacture lead tungstate with ultra-fine granularity to enhance its capacity of radiation shielding. The grain size of lead tungstate has direct impact on the ability of its protection from radioactive materials, the smaller the grain size and more uniform dispersion of lead tungstate, the better protective ability it is going to be. In this paper, soft-template synthesis was introduced to prepare ultra-fine PbWO4. Rigorous experiment conditions are settled to ensure the access to obtain ultra-fine, homogeneous lead tungstate product, and it is better than other physical and chemical preparation methods. The surface-active agent for the soft template, with S-60 for the water system W/O microemulsion zone, was used to synthesize successfully ultra-fine PbWO4. It was shown that dispersing agent S-60 in the soft template method produced ultra-fine PbWO4 with uniform granularity distribution. By using orthogonal experimental method, the best experimental conditions were obtained as follows: S-60 as surfactant dispersant with diluted 30 times concentration, solutions with pH9, 0.01 mol/L concentration of reactant, 1 300 rpm of stirring speed and slowly adding drops of Na2WO4 solution into Pb(Ac)2 solution. Based on the optimal experimental conditions, the product of ultra-fine product for .the anti-radiation protection filler has been made. The fine packing for the preparation of tungsten the gamma rays on the gloves is an average capacity of 5% or so.%钨酸铅集中了钨和铅的辐射屏蔽特性的优点,制造超细的钨酸铅可以提高辐射屏蔽的能力。利用软模板合成法研究超细PbWO4的制备工艺。以表面活性剂作软模板,用s-60为水体系的W/O微乳液区成功地合成了超细PbWO40实验结果证明,以s-60为分散剂的软模板制备的超细PbWO4粒度分布均匀。采用正交实验法探索

  2. Development of proton conducting materials and membranes based on lanthanum tungstate for hydrogen separation from gas mixtures; Entwicklung protonenleitender Werkstoffe und Membranen auf Basis von Lanthan-Wolframat fuer die Wasserstoffabtrennung aus Gasgemischen

    Energy Technology Data Exchange (ETDEWEB)

    Seeger, Janka

    2013-07-01

    Lanthanum tungstate La{sub 6-x}WO{sub 12-δ} (named LWO) is a ceramic material with mixed protonic electronic conductivity. Thereby it is a good candidate membrane material for hydrogen separation from synthesis gas in a fossil pre-combustion power plant. This work shows a material optimization by substitution targeted to clearly enhance the mixed conductivity and thereby the hydrogen flow through the LWO membrane. The first part of the work shows the synthesis and characterization of unsubstituted LWO. It points out that monophase LWO powder can be reproducibly synthesized. The La/W-ratio has to be considerably smaller than the nominal ratio of La/W = 6.0. It also depends on the used sintering conditions. Different relevant properties of LWO like stability in conditions close to application, thermal expansion, sintering behavior or microstructure were determined. Furthermore, the electrical conductivity of the material was investigated. LWO exhibits a prevailing protonic conductivity up to 750 C in wet atmospheres. Under dry atmospheres n-type conductivity was dominating. Oxygen ion and n-type conductivity dominated in wet and dry atmospheres above 750 C. The main part of the work is concerned with the development of new LWO based materials by substitutions. The aim is to achieve an improved mixed protonic electronic conductivity. Substitution elements for lanthanum side were Mg, Ca, Sr, Ba, Ce, Nd, Tb, Y and Al, while for the tungsten side Mo, Re and Ir were used. The total conductivity of the developed materials was investigated and compared to that of the unsubstituted LWO. The substitution of lanthanum led to no appreciable enhancement of the conductivity whereas the substitution of tungsten with 20 mol% molybdenum or 20 mol% rhenium clearly improved it. This caused a hydrogen flow about seven times higher for 20 mol% molybdenum- and about ten times higher for 20 mol% rhenium-substituted LWO in comparison with the unsubstituted LWO at 700 C. In the last part

  3. Effect of Mixed Glass Former on Ionic Conductivity of Silver Boro Tungstate glass system x[0.75AgI:0.25AgCl]: (1-x) [Ag2O-{B2O3:WO3}

    Science.gov (United States)

    Dehariya, Harsha; Kumar, R.; Polu, A. R.

    2012-05-01

    The idea to explore new 'Superionic Electrolytes', "Fast ionic conductors" is due to their tremendous potential applications in solid state electrochemical devices viz. solid state batteries, fuel cells, sensors, super capacitors. Superionic glasses have attracted great deal of attention due to their several advantageous over their crystalline counterparts such as high ionic conductivity, easy preparation, wide selection of compositions, isotropic properties and high stability etc [4-7]. Large numbers of silver ion based glasses have been reported in the literature for the glassy system of AgI:Ag2O: MxOy (MxOy = B2O3, SiO2, P2O5, GeO2, V2O5, As2O5, CrO3, SeO2, MoO3 & TeO3 etc many of them shows high silver ion conductivity [8]. Ion transport behavior of Silver Boro Tungstate glass system x[0.75AgI:0.25AgCl]: (1-x) [Ag2O{B2O3:WO3}], where 0 <= x <= 1 in molar wt% prepared by melt quench technique were reported. The new host [0.75AgI:0.25AgCl] was used as a better alternate in place of conventional host salt AgI. Conductivity measurement were carried out on this glass system as a function of frequency from 50 Hz to 5 MHz, over a temperature range of 27°C to 200°C, for different compositions by Impedance spectroscopy. The composition 0.7[0.75AgI:0.25AgCl]: 0.3[Ag2O{B2O3:WO3}] shows the highest conductivity of the order of σrt ~ 2.76 × 10-2 S/cm, referred to as the Optimum Conducting Composition (OCC). The enhancement in the conductivity has been obtained by mixed former effect. XRD result shows that the system is completely amorphous. Temperature dependence of conductivity of all compositions were studied & reported. Activation energies (Ea) were also evaluated from the slope of .Log(σ) vs 1000/T, Arrhenius plots.

  4. Effect of Mixed Glass Former on Ionic Conductivity of Silver Boron Tungstate glass system x[0.75AgI:0.25AgCl]: (1-x) [Ag2O-(B2O3:WO3)

    International Nuclear Information System (INIS)

    Dehariya, Harsha; Kumar, R; Polu, A R

    2012-01-01

    The idea to explore new 'Superionic Electrolytes', 'Fast ionic conductors' is due to their tremendous potential applications in solid state electrochemical devices viz. solid state batteries, fuel cells, sensors, super capacitors. Superionic glasses have attracted great deal of attention due to their several advantageous over their crystalline counterparts such as high ionic conductivity, easy preparation, wide selection of compositions, isotropic properties and high stability etc [4-7]. Large numbers of silver ion based glasses have been reported in the literature for the glassy system of AgI:Ag2O: MxOy (MxOy = B2O3, SiO2, P2O5, GeO2, V2O5, As2O5, CrO3, SeO2, MoO3 and TeO3 etc many of them shows high silver ion conductivity [8]. Ion transport behavior of Silver Boro Tungstate glass system x[0.75AgI:0.25AgCl]: (1-x) [Ag2O(B2O3:WO3)], where 0 ≤ x ≤ 1 in molar wt% prepared by melt quench technique were reported. The new host [0.75AgI:0.25AgCl] was used as a better alternate in place of conventional host salt AgI. Conductivity measurement were carried out on this glass system as a function of frequency from 50 Hz to 5 MHz, over a temperature range of 27 C to 200 C, for different compositions by Impedance spectroscopy. The composition 0.7[0.75AgI:0.25AgCl]: 0.3[Ag2O(B2O3:WO3)] shows the highest conductivity of the order of σrt ∼ 2.76x10-2 S/cm, referred to as the Optimum Conducting Composition (OCC). The enhancement in the conductivity has been obtained by mixed former effect. XRD result shows that the system is completely amorphous. Temperature dependence of conductivity of all compositions were studied and reported. Activation energies (Ea) were also evaluated from the slope of .Log(σ) vs 1000/T, Arrhenius plots.

  5. Preparation and Characterization of Facilitated Transport Membranes Composed of Chitosan-Styrene and Chitosan-Acrylonitrile Copolymers Modified by Methylimidazolium Based Ionic Liquids for CO2 Separation from CH4 and N2

    Directory of Open Access Journals (Sweden)

    Ksenia V. Otvagina

    2016-06-01

    Full Text Available CO2 separation was found to be facilitated by transport membranes based on novel chitosan (CS–poly(styrene (PS and chitosan (CS–poly(acrylonitrile (PAN copolymer matrices doped with methylimidazolium based ionic liquids: [bmim][BF4], [bmim][PF6], and [bmim][Tf2N] (IL. CS plays the role of biodegradable film former and selectivity promoter. Copolymers were prepared implementing the latest achievements in radical copolymerization with chosen monomers, which enabled the achievement of outstanding mechanical strength values for the CS-based membranes (75–104 MPa for CS-PAN and 69–75 MPa for CS-PS. Ionic liquid (IL doping affected the surface and mechanical properties of the membranes as well as the gas separation properties. The highest CO2 permeability 400 Barrers belongs to CS-b-PS/[bmim][BF4]. The highest selectivity α (CO2/N2 = 15.5 was achieved for CS-b-PAN/[bmim][BF4]. The operational temperature of the membranes is under 220 °C.

  6. Morphology, mechanical, cross-linking, thermal, and tribological properties of nitrile and hydrogenated nitrile rubber/multi-walled carbon nanotubes composites prepared by melt compounding: The effect of acrylonitrile content and hydrogenation

    Energy Technology Data Exchange (ETDEWEB)

    Likozar, Blaz, E-mail: blaz.likozar@fkkt.uni-lj.si [Polymer Competence Center Leoben GmbH, Montanuniversitaet Leoben, Roseggerstrasse 12, A-8700 Leoben (Austria); Major, Zoltan, E-mail: zoltan.major@jku.at [Polymer Competence Center Leoben GmbH, Montanuniversitaet Leoben, Roseggerstrasse 12, A-8700 Leoben (Austria)

    2010-11-01

    The purpose of this work was to prepare nanocomposites by mixing multi-walled carbon nanotubes (MWCNT) with nitrile and hydrogenated nitrile elastomers (NBR and HNBR). Utilization of transmission electronic microscopy (TEM), scanning electron microscopy (SEM), and small- and wide-angle X-ray scattering techniques (SAXS and WAXS) for advanced morphology observation of conducting filler-reinforced nitrile and hydrogenated nitrile rubber composites is reported. Principal results were increases in hardness (maximally 97 Shore, type A), elastic modulus (maximally 981 MPa), tensile strength (maximally 27.7 MPa), elongation at break (maximally 216%), cross-link density (maximally 7.94 x 10{sup 28} m{sup -3}), density (maximally 1.16 g cm{sup -3}), and tear strength (11.2 kN m{sup -1}), which were clearly visible at particular acrylonitrile contents both for unhydrogenated and hydrogenated polymers due to enhanced distribution of carbon nanotubes (CNT) and their aggregated particles in the applied rubber matrix. Conclusion was that multi-walled carbon nanotubes improved the performance of nitrile and hydrogenated nitrile rubber nanocomposites prepared by melt compounding.

  7. Effect of γ-aminopropyltriethoxy silane (γ-APS) coupling agent on mechanical and morphological properties of high density polyethylene (HDPE)/acrylonitrile butadiene rubber (NBR)/palm pressed fibre (PPF) composites

    Science.gov (United States)

    Norizan, Nabila Najwa; Santiagoo, Ragunathan; Ismail, Hanafi

    2017-07-01

    The fabrication of High Density Polyethylene (HDPE)/ Acrylonitrile-butadiene rubber (NBR)/ Palm Pressed Fibre (PPF) composite were investigated. The effect of γ-Aminopropyltriethoxy Silane (APS) as coupling agent on the properties of HDPE/ NBR/ PPF composite were studied. The composites were melt mixed using heated two roll mill at 180°C and speed of 15rpm with six different loading (100/0/10, 80/20/10, 70/30/10, 60/40/10, 50/50/10, and 40/60/10). The effects of γ-APS silane on mechanical, and morphological properties were examined using universal tensile machine (UTM) and scanning electron microscopy (SEM), respectively. Tensile strength and Young's modulus of HDPE/ NBR/ PPF composites decrease with increasing of NBR loading, whilst increasing the elongation at break. However, treated composites have resulted 3% to 29%, and 9% to 19%, higher in tensile strength and young's modulus compared to untreated composites. This was due to the better adhesion between HDPE/ NBR matrices and PPF filler with the presence of silanol moieties. From the morphological study, the micrograph of treated composites has proved the well bonded and good attachment of PPF filler with HDPE/ NBR matrices which resulted to better tensile strength to the HDPE/ NBR/ PPF composites.

  8. Morphology, mechanical, cross-linking, thermal, and tribological properties of nitrile and hydrogenated nitrile rubber/multi-walled carbon nanotubes composites prepared by melt compounding: The effect of acrylonitrile content and hydrogenation

    Science.gov (United States)

    Likozar, Blaž; Major, Zoltan

    2010-11-01

    The purpose of this work was to prepare nanocomposites by mixing multi-walled carbon nanotubes (MWCNT) with nitrile and hydrogenated nitrile elastomers (NBR and HNBR). Utilization of transmission electronic microscopy (TEM), scanning electron microscopy (SEM), and small- and wide-angle X-ray scattering techniques (SAXS and WAXS) for advanced morphology observation of conducting filler-reinforced nitrile and hydrogenated nitrile rubber composites is reported. Principal results were increases in hardness (maximally 97 Shore, type A), elastic modulus (maximally 981 MPa), tensile strength (maximally 27.7 MPa), elongation at break (maximally 216%), cross-link density (maximally 7.94 × 1028 m-3), density (maximally 1.16 g cm-3), and tear strength (11.2 kN m-1), which were clearly visible at particular acrylonitrile contents both for unhydrogenated and hydrogenated polymers due to enhanced distribution of carbon nanotubes (CNT) and their aggregated particles in the applied rubber matrix. Conclusion was that multi-walled carbon nanotubes improved the performance of nitrile and hydrogenated nitrile rubber nanocomposites prepared by melt compounding.

  9. Morphology, mechanical, cross-linking, thermal, and tribological properties of nitrile and hydrogenated nitrile rubber/multi-walled carbon nanotubes composites prepared by melt compounding: The effect of acrylonitrile content and hydrogenation

    International Nuclear Information System (INIS)

    Likozar, Blaz; Major, Zoltan

    2010-01-01

    The purpose of this work was to prepare nanocomposites by mixing multi-walled carbon nanotubes (MWCNT) with nitrile and hydrogenated nitrile elastomers (NBR and HNBR). Utilization of transmission electronic microscopy (TEM), scanning electron microscopy (SEM), and small- and wide-angle X-ray scattering techniques (SAXS and WAXS) for advanced morphology observation of conducting filler-reinforced nitrile and hydrogenated nitrile rubber composites is reported. Principal results were increases in hardness (maximally 97 Shore, type A), elastic modulus (maximally 981 MPa), tensile strength (maximally 27.7 MPa), elongation at break (maximally 216%), cross-link density (maximally 7.94 x 10 28 m -3 ), density (maximally 1.16 g cm -3 ), and tear strength (11.2 kN m -1 ), which were clearly visible at particular acrylonitrile contents both for unhydrogenated and hydrogenated polymers due to enhanced distribution of carbon nanotubes (CNT) and their aggregated particles in the applied rubber matrix. Conclusion was that multi-walled carbon nanotubes improved the performance of nitrile and hydrogenated nitrile rubber nanocomposites prepared by melt compounding.

  10. An Investigation on the Extraction and Quantitation of a Hexavalent Chromium in Acrylonitrile Butadiene Styrene Copolymer (ABS) and Printed Circuit Board (PCB) by Ion Chromatography Coupled with Inductively Coupled Plasma Atomic Emission Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Sang Ho; Kim, Yu Na [Mokpo National University, Muan (Korea, Republic of)

    2012-06-15

    A hexavalent chromium (Cr (VI)) is one of the hazardous substances regulated by the RoHS. The determination of Cr (VI) in various polymers and printed circuit board (PCB) has been very important. In this study, the three different analytical methods were investigated for the determination of a hexavalent chromium in Acrylonitrile Butadiene Styrene copolymer (ABS) and PCB. The results by three analytical methods were obtained and compared. An analytical method by UV-Visible spectrometer has been generally used for the determination of Cr (VI) in a sample, but a hexavalent chromium should complex with diphenylcarbazide for the detection in the method. The complexation did make an adverse effect on the quantitative analysis of Cr (VI) in ABS. The analytical method using diphenylcarbazide was also not applicable to printed circuit board (PCB) because PCB contained lots of irons. The irons interfered with the analysis of hexavalent chromium because those also could complex with diphenylcarbazide. In this study, hexavalent chromiums in PCB have been separated by ion chromatography (IC), then directly and selectively detected by inductively coupled plasma atomic emission spectrometry (ICP-AES). The quantity of Cr (VI) in PCB was 0.1 mg/kg

  11. p-chlorophenol anchored onto zirconium tungstate

    Indian Academy of Sciences (India)

    Unknown

    framework host materials with organic guests (Ozin 1992) and thin film .... DT-30 thermal analyser at a heating rate of 10°C min 1. ..... for particular metal ions enables it to act as an efficient ... Dines M B and Digiacomo P M 1981 Inorg. Chem.

  12. Physicochemical properties of bismuth tungstate catalysts

    International Nuclear Information System (INIS)

    Sinhamahapatra, P.K.; Bhattacharyya, S.K.; Banaras Hindu Univ.

    1979-01-01

    It is shown that in the Bi 2 O 3 -WO 3 system there are formed the following compounds: 1. Bi 2 x3WO 3 =Bi(WO 4 ) 3 tsub(m)-890 deg C 2. Bi 2 O 3 x2WO 3 =Bi 2 W 2 O 9 tsub(m)-910 deg C 3. Bi 2 O 3 xWO 3 =Bi 2 WO 6 tsub(m)-1040 deg C 4. 3BiO 3 xWO 3 =Bi 6 WO 12 tsub(m)-905 deg C In the 440-650 deg C range these compounds are characterized by endothermal maxima corresponding to dehydration and followed by exothermal maxima referred to the exothermal transition of some phases into other modifications. Increased catalytic activity is attributed to Bi 2 WO 6 phase, activity and celectivity of which are bound with the presence of W-O octahedrons connected by the angles in the solid body volume, what leads to the growth of (W-O) tetrahonal-pyramidal centres on the surface. The concentration of such supposed active centres (W=O) reaches its maximum in Bi 2 WO 6 phase, the least active phase Bi 6 WO 12 having its maximum concentration of centres as W-O-W. Samples of Bi 2 (WO 4 ) 3 and Bi 2 W 2 O 9 compositions have centres of both types. Correlation between physicochemical properties and activity shows that selective oxidation stops when Bi/W > 2, that is an active structural group of (Bi 2 O 2 ) 2+ (WO 4 ) 2- octahedron type can exist in the catalyst containing Bi up to 57%

  13. Thin films prepared from tungstate glass matrix

    Energy Technology Data Exchange (ETDEWEB)

    Montanari, B.; Ribeiro, S.J.L.; Messaddeq, Y. [Departamento de Quimica Geral e Inorganica, Instituto de Quimica, Sao Paulo State University-UNESP, CP 355, CEP 14800-900, Araraquara, SP (Brazil); Li, M.S. [Instituto de Fisica, USP, CP 369, CEP 13560-970, Sao Carlos, SP (Brazil); Poirier, G. [Departamento de Ciencias Exatas, UNIFAL-MG, CEP 37130-000, Alfenas-MG (Brazil)], E-mail: gael@unifal-mg.edu.br

    2008-01-30

    Vitreous samples containing high concentrations of WO{sub 3} (above 40% M) have been used as a target to prepare thin films. Such films were deposited using the electron beam evaporation method onto soda-lime glass substrates. These films were characterized by X-ray diffraction (XRD), perfilometry, X-ray energy dispersion spectroscopy (EDS), M-Lines and UV-vis absorption spectroscopy. In this work, experimental parameters were established to obtain stable thin films showing a chemical composition close to the glass precursor composition and with a high concentration of WO{sub 3}. These amorphous thin films of about 4 {mu}m in thickness exhibit a deep blue coloration but they can be bleached by thermal treatment near the glass transition temperature. Such bleached films show several guided modes in the visible region and have a high refractive index. Controlled crystallization was realized and thus it was possible to obtain WO{sub 3} microcrystals in the amorphous phase.

  14. Tritium diffusion in polycrystalline lithium tungstate

    International Nuclear Information System (INIS)

    Krutyakov, A.N.; Shadrin, A.A.; Saunin, E.I.; Gromov, V.V.; Shafiev, A.I.

    1984-01-01

    Using radiometric method the investigation of tritium separation from neutron irradiated (neutron flux density 1.2x10 13 n/cm 2 xs) polycrystalline Li 2 WO 4 in the temperature range 200-680 deg C has been carried out. It is established that the use of helium as gas-carrier of flow-type gas-discharge counter permits to conduct continuous stable measurements of concentrations of tritium extracted depending on its chemical state. It is shown that volume diffusion is the process, limiting tritiated particle separation rate from Li 2 WO 4 . It is found that the process of tritium volume diffusion in Li 2 WO 4 corresponds to two different mechanisms respectively in low- (200-300 deg C) and high-temperature (350-680 deg C) ranges. A supposition is made that in the low-temperature range the process of diffusion is conditioned by the dissociation of the radiation defect-tritiated particle complex, which is confirmed by the data on radiation defect annealing in Li 2 WO 4 . The value of activation energy of tritium separation process in the range 350-680 deg C, proved to be equal to 13.3 kJ/mol. Possible role of crystal structure peculiarities of Li 2 WO 4 for diffusion process is pointed out

  15. NMR measurement of identical polymer samples by round robin method. 4. Analysis of composition and monomer sequence distribution in poly(methyl methacrylate-co-acrylonitrile) leading to determinations of monomer reactivity ratios

    International Nuclear Information System (INIS)

    Hatada, Koichi; Kitayama, Tatsuki; Terawaki, Yoshio

    1995-01-01

    In order to assess the reliability of NMR measurement of polymers, 1 H and 13 C NMR data for three copolymers of methyl methacrylate (MMA) and acrylonitrile (AN) prepared with AIBN were collected from 46 spectrometers whose resonance frequencies for 1 H NMR measurements ranging from 90 to 500 MHz. 1 H and 13 C NMR spectra were measured in nitrobenzene-d 5 at 110degC and acetonitrile-d 3 at 70degC, respectively. Standard deviations (σ's) for chemical shift measurements of the 1 H and 13 C NMR signals were 0.003-0.008 ppm and 0.03-0.05 ppm, respectively. Compositions of the copolymers were determined from the relative intensities of the signals due to the OCH 3 (MMA) and CH (AN) protons, and the σ values for the determinations were 3.7-9.5%. The compositions determined from 13 C NMR (C = O for MMA unit, CN for AN unit) agreed well with those obtained from 1 H NMR. Monomer reactivity ratios r ij (i,j = 1 or 2) for a penultimate model were determined from monomer feed ratios and triad fractions obtained from the C = O (MMA) and CH (AN) carbon signals. Most of the σ values for r ij determinations were 5-14%. While r 22 and r 12 are nearly equivalent, r 11 and r 21 are significantly different from each other, indicating a possible existence of the penultimate-unit effect in the copolymerization of MMA and AN. Terminal model reactivity ratios, r 1 and r 2 , determined formally from the compositions of three samples by Fineman-Ross method showed large σ values (22-24%). (author)

  16. Comparison of sodium naphthenate and air-ionization corona discharge as surface treatments for the ethylene-tetrafluoroethylene polymer (ETFE) to improve adhesion between ETFE and acrylonitrile-butadiene-styrene polymer (ABS) in the presence of a cyanoacrylate adhesive (CAA)

    International Nuclear Information System (INIS)

    Johanning-Solís, Ana Lucía; Stradi-Granados, Benito A

    2014-01-01

    This study compares two ethylene-tetrafluoroethylene (ETFE) surface activation treatments, namely chemical attack with a solution of sodium naphthenate and plasma erosion via air-ionization corona discharge in order to improve the adhesive properties of the ETFE. An experimental design was prepared for both treatments in order to assess the effect of the treatment characteristics on the tensile load needed to break the bond between the ETFE and the acrylonitrile-butadiene-styrene polymer (ABS) formed with a cyanoacrylate adhesive (CAA) applied between them. The reason for the selection of this problem is that both polymers are frequently used in the biomedical industry for their properties, and they need to be joined firmly in biomedical devices, and the cyanoacrylate adhesive is the adhesive traditionally used for fluoropolymers, in this case the ETFE, and the same CAA has also shown good adhesion with ABS. However, the strength of the bond for the triplet ETFE-CAA-ABS has not been reported and the improvement of the strength of the bond with surface treatments is not found in scholarly journals for modern medical devices such as stents and snares. Both treatments were compared based on the aforementioned design of experiments. The case where ETFE receives no surface treatment serves as the reference. The results indicated that the three factors evaluated (initial drying of the material, temperature of the chemical bath, and immersion time), and their interactions have no significant effect over the tensile load at failure (tensile strength) of the adhesive bond being evaluated. For the air-ionization corona discharge treatment, two factors were evaluated: discharge exposition time and air pressure. The results obtained from this experimental design indicate that there is no significant difference between the levels of the factors evaluated. These results were unexpected as the ranges used were representative of the maximum ranges permissible in manufacturing

  17. Comparison of sodium naphthenate and air-ionization corona discharge as surface treatments for the ethylene-tetrafluoroethylene polymer (ETFE) to improve adhesion between ETFE and acrylonitrile-butadiene-styrene polymer (ABS) in the presence of a cyanoacrylate adhesive (CAA)

    Science.gov (United States)

    Lucía Johanning-Solís, Ana; Stradi-Granados, Benito A.

    2014-09-01

    This study compares two ethylene-tetrafluoroethylene (ETFE) surface activation treatments, namely chemical attack with a solution of sodium naphthenate and plasma erosion via air-ionization corona discharge in order to improve the adhesive properties of the ETFE. An experimental design was prepared for both treatments in order to assess the effect of the treatment characteristics on the tensile load needed to break the bond between the ETFE and the acrylonitrile-butadiene-styrene polymer (ABS) formed with a cyanoacrylate adhesive (CAA) applied between them. The reason for the selection of this problem is that both polymers are frequently used in the biomedical industry for their properties, and they need to be joined firmly in biomedical devices, and the cyanoacrylate adhesive is the adhesive traditionally used for fluoropolymers, in this case the ETFE, and the same CAA has also shown good adhesion with ABS. However, the strength of the bond for the triplet ETFE-CAA-ABS has not been reported and the improvement of the strength of the bond with surface treatments is not found in scholarly journals for modern medical devices such as stents and snares. Both treatments were compared based on the aforementioned design of experiments. The case where ETFE receives no surface treatment serves as the reference. The results indicated that the three factors evaluated (initial drying of the material, temperature of the chemical bath, and immersion time), and their interactions have no significant effect over the tensile load at failure (tensile strength) of the adhesive bond being evaluated. For the air-ionization corona discharge treatment, two factors were evaluated: discharge exposition time and air pressure. The results obtained from this experimental design indicate that there is no significant difference between the levels of the factors evaluated. These results were unexpected as the ranges used were representative of the maximum ranges permissible in manufacturing

  18. Caraterização composicional do AES - um copolímero de enxertia de poli(estireno-co-acrilonitrila em poli(etileno-co-propileno-co-dieno Compositional characterization of AES a graft copolymer based on poly(styrene-co-acrylonitrile and poly(etyhlene-co-propylene-co-diene

    Directory of Open Access Journals (Sweden)

    Renato Turchet

    2006-06-01

    Full Text Available O objetivo deste trabalho é a caracterização do AES, um copolímero de enxertia de poli(estireno-co-acrilonitrila, SAN, em poli(etileno-co-propileno-co-dieno, EPDM. Para tanto, o AES foi submetido à extração seletiva de seus componentes: o SAN livre, o EDPM livre, e o copolímero de enxertia EPDM-g-SAN. O AES e suas frações foram caracterizados por espectroscopia de infravermelho, análise elementar, calorimetria diferencial de varredura e ressonância magnética nuclear, RMN¹H e RMN13C. O AES analisado apresenta a seguinte composição em massa: 65% de EPDM-g-SAN, 13% de EPDM livre e 22% de SAN livre. O EPDM apresenta 69,8% em massa de etileno, 26,5% em massa de propileno e 4,6% em massa do dieno, 2-etilideno-5-norboneno, ENB. O SAN apresenta razão em massa acrilonitrila/estireno de 28/72 e distribuição randômica de comonômeros de estireno e acrilonitrila. Estes resultados são concordantes com a composição do AES fornecida pelo fabricante, indicando que a metodologia proposta é adequada.This work aims the characterization of AES, a graft copolymer based on poly(styrene-co-acrylonitrile, SAN, and poly(etyhlene-co-propylene-co-diene, EPDM. AES was submitted to selective extraction of its components: free SAN, EPDM chains and the graft copolymer EPDM-g-SAN. AES and its fractions were characterized by infrared spectroscopy, elemental analysis, differential scanning calorimetry, 13C and ¹H nuclear magnetic resonance. The AES has 65 wt % of EPDM-g-SAN, 13 wt % of free EPDM and 22 wt % of free SAN. EPDM has 69.8 wt % of ethylene, 26.5 wt % of propylene and 4.6 wt % of diene, 2-ethylidene-5-norbonene ENB. SAN presents acrylonitrile/styrene mass ratio of 28/72 and a random distribution of acrylonitrile and styrene comonomers. These results are in agreement with the composition reported by the AES supplier, indicating that the proposed methodology is adequate.

  19. Regenerated thermosetting styrene-co-acrylonitrile sandwich ...

    Indian Academy of Sciences (India)

    waste SAN foam and obtaining high physical performance. The jute ... as high impact strength, which limited applications in our daily life. In order to solve the problem, fibres were often introduced to ... ited Company (China) were used as the reinforcement. The ... test piece was weighed on electronic balance (accurate to.

  20. Poly(acrylonitrile-co-itaconic acid)

    Indian Academy of Sciences (India)

    Incorporations of PEDOT and PMOT on the nanoparticles were characterized by scanning electron microscopy (SEM), atomic force microscopy, Fourier transforminfrared-attenuated total reflectance spectroscopy and ultra-violet spectroscopy. These nanoparticles were blended withPAN and the blends were electrospun to ...

  1. 29 CFR 1910.1045 - Acrylonitrile.

    Science.gov (United States)

    2010-07-01

    ... monitoring. Whenever there has been a production, process, control, or personnel change which may result in... as hydrogen cyanide, oxides of nitrogen, and carbon monoxide) may be released in a fire involving... evaluation of employee exposures is performed by a competent industrial hygienist or other technically...

  2. Hydrates of the alkali trioxidomonosulfidomolybdates and -tungstates. K{sub 2}[(Mo/W)O{sub 3}S] . 1.5 H{sub 2}O and (Rb/Cs){sub 2}[(Mo/W)O{sub 3}S] . H{sub 2}O

    Energy Technology Data Exchange (ETDEWEB)

    Lehner, Anna J.; Braitsch, Milan; Roehr, Caroline [Freiburg Univ. (Germany). Inst. fuer Anorganische und Analytische Chemie

    2012-11-01

    The trioxidomonosulfidomolybdate and -tungstate anions [(Mo/W)O{sub 3}S]{sup 2-} are the first products formed when passing H{sub 2}S gas through a solution of the oxidometalates. Their potassium, rubidium and cesium salt hydrates form as crystalline precipitates from these solutions depending on pH, the polarity of the solvent, educt concentrations and temperature. The structures of the sesqui- (K) and mono- (Rb, Cs) hydrates have been determined by means of X-ray single crystal diffraction data. The potassium sesquihydrates K{sub 2}[(Mo/W)O{sub 3}S] . 1.5 H{sub 2}O are isotypic and crystallize with a new structure type (monoclinic, space group C2/c, M = Mo/W: a = 987.0(2)/993.13(11), b = 831.75(14)/831.10(11), c = 1868.9(4)/1865.2(2) pm, {beta} = 99.34(2)/99.153(8) , R1 = 0.0352/0.0390). In the crystal structure the [(Mo/W)O{sub 3}S]{sup 2-} anions are connected via hydrogen bonds to form columns along the c direction. Channels containing only water molecules run along the [101] direction. The dehydration process proceeds in a topotactic reaction between 60 to 95 C and yields crystals of the anhydrous salts K{sub 2}[(Mo/W)O{sub 3}S]. The two different K+ cations exhibit a 5 + 3 and 5 + 2 O/S coordination. The heavier alkali metal cations form the four monohydrates (Rb/Cs){sub 2}[(Mo/W)O{sub 3}S] . H{sub 2}O (trigonal rhombohedral, space group R anti 3m) with lattice parameters for the Rb/Cs molybdates of a = 621.17(6)/624.62(10), c = 3377.9(4)/3388.6(8) pm (R1 = 0.0505/0.0734) and the tungstates of a = 642.80(3)/643.3(4), c = 3532.8(3)/3566(4) pm (R1 = 0.0348/0.0660). In the structures the 3m symmetrical tetrahedra are arranged to form double layers in such a way, that the O{sub 3} bases of the tetrahedra are pointing towards each other in a staggered conformation. These double layers are stacked in the c direction in a rhombohedral sequence. In these hydrates, there are no distinct hydrogen bonds. Instead, partially disordered pairs of H{sub 2}O molecules are

  3. Buffing dust as a filler of carboxylated butadiene-acrylonitrile rubber and butadiene-acrylonitrile rubber.

    Science.gov (United States)

    Chronska, K; Przepiorkowska, A

    2008-03-01

    Buffing dust from chrome tanned leather is one of the difficult tannery wastes to manage. It is also hazardous to both human health and the environment. The scientific literature rarely reports studies on dust management, especially on its utilization as a filler for elastomers. In this connection we have made an attempt to use this leather waste as a filler for rubbers such as XNBR and NBR. The addition of the buffing dust to rubber mixes brought improvement in mechanical properties, and increase in resistance to thermal ageing as well as in electric conductivity and crosslink density of vulcalizates.

  4. Zirconium tungstate/polymer nanocomposites: Challenges and opportunities

    Energy Technology Data Exchange (ETDEWEB)

    Lind, Cora; Kozy, Leah C. [Department of Chemistry, The University of Toledo, 2801W. Bancroft Street, Toledo, OH 43606 (United States); Coleman, Maria R.; Sharma, Gayathri R. [Department of Chemical Engineering, The University of Toledo, 2801W. Bancroft Street, Toledo, OH 43606 (United States)

    2011-01-15

    Negative thermal expansion (NTE) oxides are interesting materials for use in controlled thermal expansion composites. Cubic ZrW{sub 2}O{sub 8} is one of the most promising candidates due to its strong, isotropic NTE behaviour over a large temperature range. It is easily accessible from a hydrated precursor, ZrW{sub 2}O{sub 7}(OH){sub 2}. 2H{sub 2}O, which enables control of particle size and morphology during the topotactic conversion to the NTE phase. The preparation of high quality composites poses a number of challenges like compatibility of NTE material and composite matrix, stability of the NTE phase and particle morphology and size, which affect mixing and homogeneity. For ZrW{sub 2}O{sub 8}/polymer composites, surface modification is necessary to enhance interactions between the polymer matrix and the filler particles. In addition, small particle sizes are crucial to avoid settling of filler particles during polymer processing. This review presents results on the optimization of routes to nano-ZrW{sub 2}O{sub 8}, particle modification to achieve compatibility with polymers, preparation of NTE/polyimide composites and potential problems that can interfere with composite formation. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  5. Simulation of light collection in calcium tungstate scintillation detectors

    Directory of Open Access Journals (Sweden)

    F. A. Danevich

    2015-12-01

    Full Text Available Due to high operational properties, the oxide scintillators are perspective for cryogenic scintillation experiments with aim of study rare nuclear processes. In order to optimize light yield and the energy resolution we performed calculations of the efficiency of light collection for different geometries of scintillation detector with CaWO4 crystal by Monte-Carlo method using Litrani, Geant4 and Zemax packages. The calculations were compared with experimental data in the same configurations, depending on the crystal shape, surface treatment, material and shape of the reflector and presence of optical contact. The best results were obtained with crystals shaped as the right prism with triangle base, with completely diffused surfaces, using mirror reflector shaped as a truncated cone. Simulations by using Litrani have shown the best agreement with experimental results.

  6. Metabolism of 181W - labeled sodium tungstate in goats

    International Nuclear Information System (INIS)

    Ekman, L.; Figueiras, H.D.; Jones, B.E.V.; Myamoto, S.

    1977-11-01

    Radiotungsten was given as Na 2 181 WO 4 orally to 4 goats and intravenously to 3 goats. Blood, milk, urine and faeces were collected regularly during an 8-day period. Thereafter the animals were slaughtered and different tissues were taken for analyses of 181 W. The data obtained suggest that radiotungsten is unlikely to be a significant environmental pollutant source for man, as far as its concentration in milk and meat are concerned

  7. Properties of lead tungstate crystals for high-energy physics

    CERN Document Server

    Ippolitov, M S; Burachas, S; Ikonnikov, V; Kuriakin, A; Lebedev, V; Makov, I; Man'ko, V; Nikulin, S P; Nyanin, A; Saveliev, Yu; Tamulaitis, G; Tsvetkov, A A; Vasilev, A; Vinogradov, Yu I

    2004-01-01

    Technology for the mass production of high-quality PbWO//4 (PWO) scintillating crystals is described. Scintillators produced from PWO crystals are intented for the ALICE CERN heavy ion experiment. Light yield, emission and decay time spectra as well as optical transmission of about 3600 crystals (dimensions 22 multiplied by 22 multiplied by 180 mm**3) were measured. Beam-test results of the ALICE PHOS prototype obtained with such PWO crystals are presented.

  8. Lead tungstate crystals for the ALICE/CERN experiment

    CERN Document Server

    Ippolitov, M S; Burachas, S; Ikonnikov, V; Kuriakin, A; Lebedev, V; Makov, I; Man'ko, V; Nikulin, S; Nyanin, A; Saveliev, Yu; Tamulaitis, G; Tsvetkov, A; Vasilev, A; Vinogradov, Yu I

    2005-01-01

    Light yield, emission and decay time spectra, and optical transmission of similar to 3600 (dimensions 22 multiplied by 22 multiplied by 180 mm**3) PbWO//4 (PWO) crystals were measured with test benches. Radiation beam-test results of PWO crystals are presented.

  9. Fabrication and properties of hot pressed bismuth tungstate

    International Nuclear Information System (INIS)

    Streicher, W.L.

    1978-01-01

    Bi 2 WO 6 is a synthetic polar material that is a possible candidate for energy conversion and detection systems. Previous research on this material has been concerned with crystal growth and sintering characteristics of polycrystalline compacts. This study involves itself with the fabrication of polycrystalline compacts by hot pressing techniques. Densities approaching theoretical crystal density were achieved by hot pressing at 850 0 C for one hour with pressures exceeding 35 MPa. Before hot pressing, the sintering range was determined by high temperature dilatometry of unfired Bi 2 WO 6 ceramics. Hot pressed discs were characterized by scanning electron microscopy, differential scanning calorimetry, and x-ray diffraction. Electrical properties were determined by dc resistivity, capacitance, and conductance measurements, ac poling, dc poling, and current-voltage measurements

  10. Synthesis, characterization, and properties of reduced europium molybdates and tungstates

    Energy Technology Data Exchange (ETDEWEB)

    Abeysinghe, Dileka [Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC 29208 (United States); Gerke, Birgit [Institut für Anorganische und Analytische Chemie, Universität Münster , Corrensstrasse 30, Münster D-48149 (Germany); Morrison, Gregory; Hsieh, Chun H.; Smith, Mark D. [Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC 29208 (United States); Pöttgen, Rainer [Institut für Anorganische und Analytische Chemie, Universität Münster , Corrensstrasse 30, Münster D-48149 (Germany); Makris, Thomas M. [Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC 29208 (United States); Loye, Hans-Conrad zur, E-mail: zurloye@mailbox.sc.edu [Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC 29208 (United States)

    2015-09-15

    Single crystals of K{sub 0.094}Eu{sub 0.906}MoO{sub 4}, K{sub 0.097}Eu{sub 0.903}WO{sub 4}, EuWO{sub 4}, and EuMoO{sub 4} were grown from molten chloride fluxes contained in vacuum-sealed fused silica and structurally characterized via single crystal X-ray diffraction. The in situ reduction of Eu{sup 3+} to Eu{sup 2+} was carried out using Mo, W, and Zn as metal reducing agents. All four compounds crystallize in the tetragonal space group of I4{sub 1}/a and adopt the scheelite (CaWO{sub 4}) structure type. The magnetic susceptibility of the reported compounds shows paramagnetic behavior down to 2 K. {sup 151}Eu Mössbauer spectroscopy was used to analyze the relative Eu{sup 2+} and Eu{sup 3+} content of the samples. All the compounds were further characterized by EPR, and UV-vis spectroscopy. - Graphical abstract: TOC Caption Two new reduced europium containing quaternary oxides, K{sub 0.094}Eu{sub 0.906}MoO{sub 4} and K{sub 0.097}Eu{sub 0.903}WO{sub 4}, and two previously reported ternary reduced oxides, EuWO{sub 4} and EuMoO{sub 4}, were synthesized via an in situ reduction of Eu{sup 3+} to Eu{sup 2+} under flux method using Mo, W, and Zn as metal reducing agents. {sup 151}Eu Mössbauer spectroscopy was used to analyze the relative Eu{sup 2+} and Eu{sup 3+} content of the samples. - Highlights: • K{sub 0.094}Eu{sub 0.906}MoO{sub 4}, K{sub 0.097}Eu{sub 0.903}WO{sub 4}, EuWO{sub 4}, and EuMoO{sub 4} have been synthesized and characterized. • The in situ reduction of Eu{sup 3+} to Eu{sup 2+} was carried out using Mo, W, and Zn as metal reducing agents. • Magnetic susceptibility data were collected. • {sup 151}Eu Mössbauer spectroscopy was used to analyze Eu{sup 2+} and Eu{sup 3+} content.

  11. Tungstate as a synergist to phosphonate-based formulation for ...

    Indian Academy of Sciences (India)

    Administrator

    Synergistic inhibition of corrosion of carbon steel in low chloride aqueous .... 200 high resolution scanning electron microscope ..... mation of a thick and less permeable protective film ..... the surface of the metal due to its very low solubility.

  12. Analysis of photoluminescence spectra of lead-tungstate single crystals

    International Nuclear Information System (INIS)

    Kim, Do Hyung; Lee, Sang Yun; Lee, Myoung Bok

    2003-01-01

    In addition to the intrinsic blue emission band near 430 nm for an ideal PbWO 4 scheelite structure, the presence of three extra emission bands peaking near blue-green and green-red colors was clearly identified for thermally synthesized bulk crystals with the help of a reliable fitting process applicable for microscopic analysis of recorded PL spectra. The origin, nature, and electro-optical behaviors of the extra emission bands are strongly related to the structural change from an ideal scheelite to modified ones, so now we can more closely track down the nature and the relevant behaviors, which are still in dispute, of the apparent colors of the PbWO 4 scintillating medium by constructing structural models and by considering the energy transfer mechanism between the color centers

  13. Pressure induced graft-co-polymerization of acrylonitrile onto ...

    Indian Academy of Sciences (India)

    WINTEC

    The natural fibre (S. cilliare) (0⋅5 g) was masticated to create active sites onto the polymeric backbone and was then immersed in a known amount of distilled water for. 24 h. A known amount of initiator (FAS–KPS) and monomer (AN) were then added to the flask containing fibre at suitable pH and the reaction was carried ...

  14. Nitrilase-catalysed conversion of acrylonitrile by free and ...

    Indian Academy of Sciences (India)

    Prakash

    microorganisms directly to carboxylic acids and ammonia using a nitrilase or nitrile ... and enzymatic detoxification of nitrile-based herbicides,and ... Materials and methods. 2.1 Growth ... determined by a UV detector at a wavelength of 210 nm.

  15. Synthesis and ammonolysis of nickel and cobalt tungstates and their characterisation

    Directory of Open Access Journals (Sweden)

    J.L. Rico

    2016-07-01

    Full Text Available The synthesis and characterization of NiW and CoW compounds are herein reported. The NiWO4 and CoWO4 samples, successfully synthesised by the hydrothermal method, were treated under NH3 to obtain the metal nitride. The SEM micrographs show that this transformation is a topotactic process. Tungsten trioxide was also treated under NH3 at similar operating conditions, and used as a reference. High nitrogen contents after ammonolysis were calculated, however, the percentages were below the theoretical values assuming the formation of pure NiWN, CoWN and WN. The XRD pattern indicates that WON is likely formed after ammonolysis of tungsten oxide whereas phase segregation was observed on the nickel and cobalt samples. Furthermore, the reactivity of the nitride samples as function of temperature was measured under argon and the results show that most of the nitrogen is removed from the cobalt and nickel samples whereas it was partially released from the tungsten specimen.

  16. Nano-Zirconium Tungstate Reinforced Liquid Crystalline Thermosetting Composites with Near Zero Thermal Expansion

    Science.gov (United States)

    2015-06-25

    Novel Bainitic Steel . Scripta Materialia 2005, 52, 461-466. (92)Nicholson, D. M. C.; Kisner, R. A.; Ludtka, G. M.; Sparks, C. J.; Petit, L.; Jaramillo...P. N., In Situ Evidence of Enhanced Transformation Kinetics in a Medium Carbon Steel Due to a High Magnetic Field. Scripta Materialia 2004, 51, 171

  17. Certifying procedures for lead tungstate crystal parameters during mass production for the CMS ECAL

    CERN Document Server

    Auffray, Etiennette; Chipaux, Rémi; Drobychev, G Yu; Dromby, G; Fedorov, A A; Freire, M; Géléoc, M; Kondratev, O V; Korzhik, M V; Lecoq, P; Le Goff, J M; Letournel, P; Lopatic, A R; Missevitch, O V; Oriboni, A; Oskine, A V; Panov, B M; Peigneux, J P; Schneegans, M; Singovsky, A V; Zouevski, R F

    1998-01-01

    Certifying procedures and fully automated equipment for testing of Pb WO/sub 4/ (PWO) scintillators have been developed. The parameters to be verified are the optical transmission spectra in the longitudinal and transversal $9 directions; the light yield and its non-uniformity along the crystal; the scintillation kinetics; the radiation hardness and the dimensions. Both the precision of measurements and the output rate meet the stringent requirements of $9 the mass production stage of PWO scintillating elements for the CMS electromagnetic calorimeter at CERN (full characterization of several tens of crystals per day for five years). This is achieved by a) the implementation of a $9 `start- stop' technique with high count rate capability for scintillation decay measurement; b) the development of special compact fast scanning spectrophotometers; c) the application of a multi-axis movement system for crystal and $9 spectrometers; d) the use of a standard programmable 3D machine for precise dimension measurement....

  18. Random lasing in Nd{sup 3+} doped potassium gadolinium tungstate crystal powder

    Energy Technology Data Exchange (ETDEWEB)

    Moura, André L., E-mail: andre.moura@fis.ufal.br [Grupo de Física da Matéria Condensada, Núcleo de Ciências Exatas – NCEx, Campus Arapiraca, Universidade Federal de Alagoas, 57309-005, Arapiraca, AL (Brazil); Departamento de Física, Universidade Federal de Pernambuco, 50670-901 Recife, PE (Brazil); Fewo, Serge I. [Departamento de Física, Universidade Federal de Pernambuco, 50670-901 Recife, PE (Brazil); Laboratory of Mechanics, Department of Physics, University of Yaoundé I, Yaoundé (Cameroon); Carvalho, Mariana T.; Gomes, Anderson S. L.; Araújo, Cid B. de [Departamento de Física, Universidade Federal de Pernambuco, 50670-901 Recife, PE (Brazil); Kuzmin, Andrey N.; Prasad, Paras N. [Institute for Lasers, Photonics and Biophotonics, The State University of New York, Buffalo, New York 14260-3000 (United States)

    2015-02-28

    Random laser (RL) emission in Nd{sup 3+} doped potassium gadolinium tungstate—KGd(WO{sub 4}){sub 2}:Nd{sup 3+}—crystal powder is demonstrated. The powder was excited at 813 nm in resonance with the Nd{sup 3+} transition {sup 4}I{sub 9/2}→{sup 4}F{sub 5/2}. RL emission at 1067 nm due to the {sup 4}F{sub 3/2}→{sup 4}I{sub 11/2} transition was observed and characterized. An intensity threshold dependent on the laser spot area and bandwidth narrowing from ≈2.20 nm to ≈0.40 nm were observed and measured. For a beam spot area of 0.4 mm{sup 2}, a RL threshold of 6.5 mJ/mm{sup 2} (90 MW/cm{sup 2}) was determined. For excitation intensity smaller than the RL threshold, only spontaneous emission from level {sup 4}F{sub 3/2} with decay time in the tens microsecond range was observed, but for excitation above the RL threshold, significant shortening of excited level lifetime, characteristic of a stimulated process was found. The overall characteristics measured show that KGd(WO{sub 4}){sub 2}:Nd{sup 3+} is an efficient material for operation of solid state RLs in the near-infrared.

  19. Simulation study of negative thermal expansion in yttrium tungstate Y2W3O12.

    Science.gov (United States)

    Rimmer, Leila H N; Dove, Martin T

    2015-05-13

    A simulation study of negative thermal expansion in Y2W3O12 was carried out using calculations of phonon dispersion curves through the application of density functional perturbation theory. The mode eigenvectors were mapped onto flexibility models and results compared with calculations of the mode Grüneisen parameters. It was found that many lower-frequency phonons contribute to negative thermal expansion in Y2W3O12, all of which can be described in terms of rotations of effectively rigid WO4 tetrahedra and Y-O rods. The results are strikingly different from previous phonon studies of higher-symmetry materials that show negative thermal expansion.

  20. Calculated powder x-ray diffraction data for three tantalum tungstates

    International Nuclear Information System (INIS)

    Holcombe, C.E. Jr.

    1976-11-01

    A study was made of computer-simulated powder x-ray diffraction data for Ta 22 W 4 O 67 , Ta 2 WO 8 , and Ta 16 W 18 O 94 --the three compounds in the Ta 2 O 5 --WO 3 system from 27 to 69 mole percent WO 3 . The crystal structures of Ta 2 WO 8 and one form of Ta 16 W 18 O 94 (Type B) were deduced from reported data. 8 tables

  1. The influence on intrinsic light emission of calcium tungstate and molybdate powders by multivalence Pr codoping

    International Nuclear Information System (INIS)

    Zhu, Fang; Xiao, Zhisong; Yan, Lu; Zhang, Feng; Huang, Anping

    2010-01-01

    For trivalent praseodymium (Pr 3+ ) and quadrivalent praseodymium (Pr 4+ ) codoped CaMO 4 (M = W, Mo) powders, the luminescence propriety of matrix is obviously influenced by carrier concentration. The light emission intensity of CaWO 4 matrix decreases exponentially with increasing of Pr concentration because oxygen-deficient (WO 3 .V O ) obtains an electron supplied by Pr 3+ (5d). However, the light emission intensity of CaMoO 4 is enhanced by Pr codoping because the quasi-free electrons increase the probability of radiative combination. The difference of photoluminescence properties in the two materials are attributed to the bonding character of M and O in the CaMO 4 structure. (orig.)

  2. Electrochemical reaction of lithium with orthorhombic bismuth tungstate thin films fabricated by radio-frequency sputtering

    International Nuclear Information System (INIS)

    Li Chilin; Sun Ke; Yu Le; Fu Zhengwen

    2009-01-01

    Bi 2 WO 6 thin films with fast deposition rate have been fabricated by radio-frequency (R.F.) sputtering deposition, and are used as positive electrodes in rechargeable thin film lithium batteries. An initial discharge capacity of 113 μAh/cm 2 -μm is obtainable for Bi 2 WO 6 film electrode with good capacity reversibility. A multiple-center reactive mechanism associated with both Bi 3+ /Bi 0 and W 6+ /W x+ (x 2 WO 6 electrochemical performance with those of Bi 2 O 3 and WO 3 thin films. A possible explanation about smooth capacity loss of Bi 2 WO 6 after long-term cycling is suggested from the incomplete reaction of Bi component. The advantages of Bi 2 WO 6 thin films over the singer-center Bi 2 O 3 or WO 3 thin films are shown in both the aspects of volumetric capacity and cycling life.

  3. Non-stoichiometry defects and radiation hardness of lead tungstate crystals PbWO sub 4

    CERN Document Server

    Devitsin, E G; Potashov, S Yu; Terkulov, A R; Nefedov, V A; Polyansky, E V; Zadneprovski, B I; Kjellberg, P; Korbel, V

    2002-01-01

    It has been stated many times that the formation of radiation infringements in PbWO sub 4 is to a big extent stipulated by the non-stoichiometry defects of the crystals, arising in the process of their growth and annealing. To refine the idea of characteristics of the non-stoichiometry defects and their effect on the radiation hardness of PbWO sub 4 , the current study is aimed at the melt composition infringements during its evaporation and at optical transmission of crystals obtained in these conditions after their irradiation ( sup 1 sup 3 sup 7 Cs source). In the optical transmission measurements along with traditional techniques a method 'in situ' was used, which provided the measurements in fixed points of the spectrum (380, 470 and 535 nm) directly in the process of the irradiation. X-ray phase and fluorescence analysis of condensation products of vapours over PbWO sub 4 melt has found PbWO sub 4 phase in their content as well as compounds rich in lead PbO, Pb sub 2 WO sub 5 with overall ratio Pb/W (3....

  4. Non-stoichiometry Defects and Radiation Hardness of Lead Tungstate Crystals PbWO4

    CERN Document Server

    Devitsin, E G; Kozlov, V A; Nefedov, L; Polyansky, E V; Potashov, S Yu; Terkulov, A R; Zadneprovski, B I

    2001-01-01

    It has been stated many times that the formation of radiation infringements in PbWO4 is to big extent stipulated by non-stoichiometry defects of the crystals, arising in the process of their growth and annealing. To refine the idea of characteristics of non-stoichiometry defects and their effect on the radiation hardness of PbWO4 the current study is aimed at the melt composition infringements during its evaporation and at optical transmission of crystals obtained in these conditions after their irradiation (137Cs source). In the optical transmission measurements along with traditional techniques a method "in situ" was used, which provided the measurements in fixed points of the spectrum (380, 470 and 535 nm) directly in the process of the irradiation. X-ray phase and fluorescence analysis of condensation products of vapours over PbWO4 melt has found PbWO4 phase in their content as well as compounds rich in lead, PbO, Pb2WO5, with overall ratio Pb/W = 3.2. Correspondingly the lack of lead and variations in th...

  5. Neurobehavioral Effects of Sodium Tungstate Exposure on Rats and Their Progeny

    National Research Council Canada - National Science Library

    Mclnturf, S. M; Bekkedal, M. Y; Olabisi, A; Arfsten, D; Wilfong, E; Casavant, R; Jederberg, W; Gunasekar, P. G; Chapman, G

    2007-01-01

    ... consequences of exposure. The purpose of this study was to use a battery of tests as an initial screen for potential neurobehavioral effects that may be associated with 70 days of daily tungsten exposure via drinking water...

  6. Members of the ALICE collaboration greet the arrival of the experiment's first 500 lead tungstate crystals

    CERN Multimedia

    Maximilien Brice

    2002-01-01

    L. to r: Vladislav Manko (Kurchatov Institute, Moscow, PHOS project leader), Arne Klovning (University of Bergen, PHOS technical coordinator), Vyacheslav Demanov (VNIIEF, Sarov), Bjorn Pommeresche (University of Bergen), Hans de Groot (CERN, ALICE resource coordinator), Dimitri Alexandrov (Kurchatov Institute, Moscow), Mikhail Ippolitov (Kurchatov Institute, Moscow), Yuri Vinogradov (VNIIEF, Sarov), Chris Fabjan (CERN, ALICE technical coordinator), Yuri Sibiriak (Kurchatov Institute, Moscow), Sergei Sadovsky (IHEP, Protvino), Jurgen Schukraft (CERN, ALICE spokesperson).

  7. Normal coordinate treatment and Raman intensity analysis of yttrium vanadate and calcium tungstate crystal

    Energy Technology Data Exchange (ETDEWEB)

    Budha Addepalli, V; Kumar, S P; Padma, V A; Rajeswara Rao, N [Osmania Univ., Hyderabad (India). Dept. of Physics

    1976-09-01

    Raman scattering tensors of crystalline YVO/sub 4/ and CaWO/sub 4/ are derived. Using the spectra of YVO/sub 4/, the intensities are substituted in the formulae. They are used to determine the polarizability derivatives of V-O bond. Substituting them back into the intensity formulae, a number of equations involving the L elements are obtained. Supplementing them with the matrix equation LL' = G, and using L'FL = ..gamma.., a-l the F-elements are determined. It is observed that the force constants relating to the translations of the group YVO/sub 4/ are quite high, explaining the high melting point of the crystal.

  8. A high resolution electromagnetic calorimeter based on lead-tungstate crystals

    Czech Academy of Sciences Publication Activity Database

    Aleksandrov, D. V.; Burachas, S.F.; Ippolitov, M.S.; Mareš, Jiří A.; Polák, Karel

    2005-01-01

    Roč. 550, - (2005), s. 169-184 ISSN 0168-9002 Institutional research plan: CEZ:AV0Z10100521 Keywords : PbWO 3 * high resolution electromagnetic calorimeter Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.224, year: 2005

  9. Optical absorption analysis of quaternary molybdate- and tungstate-ordered double perovskites

    Energy Technology Data Exchange (ETDEWEB)

    Tablero, C., E-mail: ctablero@etsit.upm.es

    2015-08-05

    Highlights: • These compounds present a high optical absorption. • The absorption coefficients using different DFT + U alternatives have been compared. • The absorption coefficients have been split into different contributions. • The maximum efficiency is near the maximum efficiency for multiple-gap solar cells. - Abstract: Quaternary-ordered double perovskite A{sub 2}MM′O{sub 6} (M = Mo,W) semiconductors are a group of materials with a variety of photocatalytic and optoelectronic applications. An analysis focused on the optoelectronic properties is carried out using first-principles density-functional theory with several U orbital-dependent one-electron potentials applied to different orbital subspaces. The structural non-equivalence of the atoms resulting from the symmetry has been taken in account. In order to analyze optical absorption in these materials deeply, the absorption coefficients have been split into inter- and intra-non-equivalent species contributions. The results indicate that the effect of the A and M′ atoms on the optical properties are minimal whereas the largest contribution comes from the non-equivalent O atoms to M transitions.

  10. Nano-sized copper tungstate thin films as positive electrodes for rechargeable Li batteries

    International Nuclear Information System (INIS)

    Li Chilin; Fu Zhengwen

    2008-01-01

    Nano-sized CuWO 4 thin films have been fabricated by radio-frequency (R.F.) sputtering deposition, and are used as positive electrode with both LiClO 4 liquid electrolyte and LiPON solid electrolyte in rechargeable lithium batteries. An initial discharge capacity of 192 and 210 mAh/g is obtainable for CuWO 4 film electrode with and without coated LiPON in liquid electrolyte, respectively. An all-solid-state cell with Li/LiPON/CuWO 4 layers shows a high-volume rate capacity of 145 μAh/cm 2 μm in first discharge, and overcomes the unfavorable electrochemical degradation observed in liquid electrolyte system. A two-step reactive mechanism is investigated by both transmission electron microscopy and selected area electron diffraction techniques. Apart from the extrusion and injection of Cu 2+ /Cu 0 , additional capacity can be achieved by the reversible reactivity of (WO 4 ) 2- framework. The chemical diffusion coefficients of Li intercalation/deintercalation are estimated by cyclic voltammetry. Nano-CuWO 4 thin film is expected to be a promising positive electrode material for high-performance rechargeable thin-film lithium batteries

  11. Structure refinement of commensurately modulated bismuth tungstate, Bi2WO6

    International Nuclear Information System (INIS)

    Rae, A.D.; Thompson, J.G.; Withers, R.L.

    1991-01-01

    The displacive ferroelectric Bi 2 WO 6 [M r = 697.81, a = 5.4559 (4), b = 5.4360 (4), c = 16.4298 (17) A, Z = 4, D x = 9.512 g cm -3 , MoKα, λ = 0sun7107 A, μ = 958.6 cm -1 , F(000) = 1151.73], is described at room temperature as a commensurate modulation of an idealized Fmmm parent structure derived from an I4/mmm structure. Transmission electron microscopy clearly showed that there are coherent intergrowths of two distinct modulated variants in Bi 2 WO 6 crystals. Displacive models of inherent F2mm and Bmab symmetry are substantial and coherent over a large volume. They reduce the space-group symmetry to B2ab. A further substantial displacive mode corresponds to rotation of corner-connected WO 6 octahedra about axes parallel to c and has either of two inherent symmetries, Abam or Bbam, the difference being associated with the way this mode reduces the space-group symmetry to P2 1 ab, while the existence of the Bbam mode reduces the intensity of h + l = 2n + 1 data and acts like a stacking fault. Group theoretical analysis of the problem details how the X-ray data can be classified so as to monitor the refinement. Anomalous dispersion selects the overall sign of the F2mm mode and determines the polarity. The overall signs chosen for the Bmab and Abam symmetry components of atom displacements select between equivalent origins. The overall signs of induced modes of inherent Amam, Bbab and Ccma symmetry had to be determined by comparative refinement since the assumption that calculated phases are best estimates can retain the initial overall sign choice for these modes during least-squares refinement. Correlations between the dominant modes and the induced modes allowed a meaningful choice of signs to resolve the pseudo homometry. Only the sign of the Bbab mode was capable of self-correction during refinement. (orig./BHO)

  12. Dynamic Response of Acrylonitrile Butadiene Styrene Under Impact Loading (Open Access)

    Science.gov (United States)

    2016-03-16

    Ivankovic, A., & Venizelos, G. (2000). High strain rate properties of selected aluminium alloys . Materials Science and Engineering: A., 278, 225–235...deformation, there has been extensive work on understanding the effects of high strain rate on metals such as aluminum alloys , steels, and other metals...2005) conducted studies on the dynamic deformation of copper and titanium alloys and observed that the maximum stress did not change drastic- ally

  13. From Green Aerogels to Porous Graphite by Emulsion Gelation of Acrylonitrile

    Science.gov (United States)

    2012-01-01

    interparticle covalent bridging in the mechanical properties of aerogels,30 we have opted for a bottom-up process, whereas PAN aerogels are...series that employs the hanging pendant drop method, and data were analyzed using the Young−Laplace equation through the instrument software. Elemental...that the layer of the surfactant prevents intimate contact and efficient covalent bridging between the skeletal nanoparticles. Overall, our ability to

  14. 21 CFR 177.1480 - Nitrile rubber modified acrylonitrile-methyl acrylate copolymers.

    Science.gov (United States)

    2010-04-01

    ...-methyl acrylate copolymers identified in this section may be safely used as components of articles... Applied Nutrition (HFS-200), Food and Drug Administration, 5100 Paint Branch Pkwy., College Park, MD 20740...

  15. 21 CFR 177.1030 - Acrylonitrile/butadiene/styrene/methyl methacrylate copolymer.

    Science.gov (United States)

    2010-04-01

    ... methacrylate copolymer identified in this section may be safely used as an article or component of articles... monomer content of the finished copolymer articles is not more than 11 parts per million as determined by... available from the Center for Food Safety and Applied Nutrition (HFS-200), Food and Drug Administration...

  16. Poly(acrylonitrile-co-itaconic acid)–poly(3,4-ethylenedioxythiophene ...

    Indian Academy of Sciences (India)

    2017-08-28

    Aug 28, 2017 ... These excellent properties lead them to be used in many industrial ... cosmetics, electromagnetic shielding, photovoltaic devices, ... violet (UV)–visible spectroscopy, atomic force microscopy. (AFM) and ... determined to be 20 wt%. .... that ratio of absorbance of P(AN-co-IA) to PAN is found to be. 1.46.

  17. Rubber-toughened polypropylene/acrylonitrile-co-butadiene-co-styrene blends: Morphology and mechanical properties

    Czech Academy of Sciences Publication Activity Database

    Šlouf, Miroslav; Kolařík, Jan; Kotek, Jiří

    2007-01-01

    Roč. 47, č. 5 (2007), s. 582-592 ISSN 0032-3888 R&D Projects: GA ČR GP106/02/P029; GA ČR GA106/04/1051 Institutional research plan: CEZ:AV0Z40500505 Keywords : polymer blends * co-continuity * predictive models Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.272, year: 2007

  18. Enhancement the Thermal Stability and the Mechanical Properties of Acrylonitrile-Butadiene Copolymer by Grafting Antioxidant

    Directory of Open Access Journals (Sweden)

    Abdulaziz Ibrahim Al-Ghonamy

    2010-01-01

    Full Text Available Monomeric antioxidants are widely used as effective antioxidants to protect polymers against thermal oxidation. Low molecular weight antioxidants are easily lost from polymer through migration, evaporation, and extraction. Physical loss of antioxidants is considered to be major concern in the environmental issues and safety regulation as well as long life time of polymers. The grafting copolymerization of natural rubber and o-aminophenol was carried out by using two-roll mill machine. The prepared natural rubber-graft-o-Aminophenol, NR-graft-o-AP, was analysed by using Infrared and 1H-NMR Spectroscopy techniques. The thermal stability, mechanical properties, and ultrasonic attenuation coefficient were evaluated for NBR vulcanizates containing the commercial antioxidant, N-phenyl--naphthylamine (PBN, the prepared grafted antioxidant, NR-graft-o-AP, and the control vulcanizate. Results of the thermal stability showed that the prepared NR-graft-o-AP can protect NBR vulcanizate against thermal treatment much better than the commercial antioxidant, PBN, and control mix, respectively. The prepared grafted antioxidant improves the mechanical properties of NBR vulcanizate.

  19. Enhancement the Thermal Stability and the Mechanical Properties of Acrylonitrile-Butadiene Copolymer by Grafting Antioxidant

    International Nuclear Information System (INIS)

    Al-Ghonamy, A.I.; El-Wakil, A.A.; Ramadan, M.; El-Wakil, A.A.; Ramadan, M.

    2010-01-01

    Monomeric antioxidants are widely used as effective antioxidants to protect polymers against thermal oxidation. Low molecular weight antioxidants are easily lost from polymer through migration, evaporation, and extraction. Physical loss of antioxidants is considered to be major concern in the environmental issues and safety regulation as well as long life time of polymers. The grafting copolymerization of natural rubber and o-aminophenol was carried out by using two-roll mill machine. The prepared natural rubber-graft-o-Aminophenol, NR-graft-o-AP, was analysed by using Infrared and 1H-NMR Spectroscopy techniques. The thermal stability, mechanical properties, and ultrasonic attenuation coefficient were evaluated for NBR vulcanizations containing the commercial antioxidant, N-phenyl-β-naphthylamine (PBN), the prepared grafted antioxidant, NR-graft-o-AP, and the control vulcanization. Results of the thermal stability showed that the prepared NR-graft-o-AP can protect NBR vulcanization against thermal treatment much better than the commercial antioxidant, PBN, and control mix, respectively. The prepared grafted antioxidant improves the mechanical properties of NBR vulcanization.

  20. Synthesis, Characterization and Photophysical Properties of Pyridine-Carbazole Acrylonitrile Derivatives

    Directory of Open Access Journals (Sweden)

    Gabriel Ramos-Ortiz

    2011-03-01

    Full Text Available We synthesized three novel highly fluorescent compounds, 2-(2’-pyridyl-3-(N-ethyl-(3’-carbazolylacrylonitrile, 2-(3”-pyridyl-3-(N-ethyl-(3’-carbazolylacrylonitrile, and 2-(4-pyridyl-3-(N-ethyl-(3’-carbazolylacrylonitrile by Knoevenagel condensation. The first two were synthesized without solvent in the presence of piperidine as a catalyst; the third was synthesized without a catalyst and with N,N-dimethylformamide as a solvent. In solution, the molar absorption coefficients showed absorptions at 380, 378, and 396 nm, respectively; in solid state, absorptions were at 398, 390, and 442 nm, respectively. The fluorescence emission was at 540, 540 and 604 nm, respectively, the 2-(4-pyridyl-3-(N-ethyl-(3’-carbazolylacrylonitrile showed a red shift in the emission of 64 nm compared to the other two compounds. The fluorescence quantum yield for the compounds in powder form showed values of 0.05, 0.14, and 0.006, respectively; compared with the value measured for the Alq3 reference, 2-(3”-pyridyl-3-(N-ethyl-(3’-carbazolylacrylonitrile had a lightly higher value. The third harmonic generation measurement for 2-(2’-pyridyl-3-(N-ethyl-(3’-carbazolylacrylonitrile yielded a χ(3 value of 5.5 × 10−12 esu, similar to that reported for commercial polymers.

  1. A comparison of the characteristics of excimer and femtosecond laser ablation of acrylonitrile butadiene styrene (ABS)

    International Nuclear Information System (INIS)

    See, Tian Long; Liu, Zhu; Li, Lin; Zhong, Xiang Li

    2016-01-01

    Highlights: • Ablation threshold for excimer laser is lower compared to femtosecond laser. • Effective optical penetration depth for excimer laser is lower compared to femtosecond laser. • Two ablation characteristic regimes are observed for femtosecond laser ablation. • Reduction of C=C bond following excimer or fs laser ablation is observed. • Addition of oxygen- and nitrogen-rich functional groups is observed. - Abstract: This paper presents an investigation on the ablation characteristics of excimer laser (λ = 248 nm, τ = 15 ns) and femtosecond laser (λ = 800 nm, τ = 100 fs) on ABS polymer sheets. The laser–material interaction parameters (ablation threshold, optical penetration depth and incubation factor) and the changes in material chemical properties were evaluated and compared between the two lasers. The work shows that the ablation threshold and effective optical penetration depth values are dependent on the wavelength of laser beam (photon energy) and the pulse width. The ablation threshold value is lower for the excimer laser ablation of ABS (F_t_h = 0.087 J/cm"2) than that for the femtosecond laser ablation of ABS (F_t_h = 1.576 J/cm"2), demonstrating a more dominating role of laser wavelength than the pulse width in influencing the ablation threshold. The ablation depth versus the logarithmic scale of laser fluence shows two linear regions for the fs laser ablation, not previously known for polymers. The effective optical penetration depth value is lower for excimer laser ablation (α"−"1 = 223 nm) than that for femtosecond laser ablation (α"−"1 = 2917 nm). The ablation threshold decreases with increasing number of pulses (NOP) due to the chain scission process that shortens the polymeric chains, resulting in a weaker polymeric configuration and the dependency is governed by the incubation factor. Excimer laser treatment of ABS eliminates the C=C bond completely through the chain scission process whereas C=C bond is partially eliminated through the femtosecond laser treatment due to the difference in photon energy of the two laser beams. A reduction in the C=C bond through the chain scission process creates free radical carbons which then form crosslinks with each other or react with oxygen, nitrogen and water in air producing oxygen-rich (C−O and C=O bond) and nitrogen-rich (C−N) functional groups.

  2. Structure and Piezoelectricity of Poly (styrene-co-acrylonitrile) Copolymer Doped with Different Dyes

    Czech Academy of Sciences Publication Activity Database

    Elhadidy, Hassan; Abdelhamid, M.I.; Aboelwafa, A.M.; Habib, A.

    2013-01-01

    Roč. 52, č. 12 (2013), s. 1277-1284 ISSN 0360-2559 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0068; GA MŠk(CZ) EE2.3.20.0214 Institutional support: RVO:68081723 Keywords : DANS * DAST * Piezo- and pyro- electricity * SAN * structure * TDSC Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.481, year: 2012

  3. Adhesion and adhesion changes at the copper metal-(acrylonitrile-butadiene-styrene) polymer interface

    NARCIS (Netherlands)

    Kisin, S.; Varst, van der P.G.T.; With, de G.

    2007-01-01

    It is known that the adhesive strength of metallic films on polymer substrates often changes in the course of time. To study this effect in more detail, the adhesion energy of sputtered and galvanically strengthened copper coatings on acrylonitrile–butadiene–styrene polymer substrate was determined

  4. Preparation and properties of blends of polypropylene and acrylonitril-butadiene-styrene with thermoplastic starch

    International Nuclear Information System (INIS)

    Kaseem, M.; Deri, F.

    2012-01-01

    In the present work the rheological and mechanical properties of polypropylene / thermoplastic starch (PP/TPS) and acrylo nitril-butadiene-styrene/ thermoplastic starch (ABS/TPS) blends were investigated. Starch was plasticised using glycerol and blends were prepared using a laboratory scale with single screw extruder. Rheological properties of the prepared blends were determined using a capillary rheometer. Mechanical properties were studied in term of tensile tests, stress at break, strain at break and young's modulus were determined. Rheological results showed that the blends are pseudo plastic in manner and the true viscosity of Pp/TPS blend decreases with increasing TPS content in the blend until 10%, and at more than 10% TPS it increases with increasing TPS. In ABS/TPS, the true viscosity decreases with increasing TPS content in the blend. The mechanical results showed that in both systems, the stress at break and strain at break decrease with increasing TPS content in the blend while the young's modulus increases with increasing TPS content. The mechanical results shown that the addition of TPS to each of PP and ABS follows the general trend for filler effects on polymer properties. (author)

  5. A comparison of the characteristics of excimer and femtosecond laser ablation of acrylonitrile butadiene styrene (ABS)

    Energy Technology Data Exchange (ETDEWEB)

    See, Tian Long, E-mail: tianlong.see@postgrad.manchester.ac.uk [Corrosion and Protection Centre, School of Materials, The Mill, The University of Manchester, M13 9PL Manchester (United Kingdom); Laser Processing Research Centre, School of Mechanical, Aerospace and Civil Engineering, The University of Manchester, M13 9PL Manchester (United Kingdom); Liu, Zhu [Corrosion and Protection Centre, School of Materials, The Mill, The University of Manchester, M13 9PL Manchester (United Kingdom); Li, Lin [Laser Processing Research Centre, School of Mechanical, Aerospace and Civil Engineering, The University of Manchester, M13 9PL Manchester (United Kingdom); Zhong, Xiang Li [Corrosion and Protection Centre, School of Materials, The Mill, The University of Manchester, M13 9PL Manchester (United Kingdom)

    2016-02-28

    Highlights: • Ablation threshold for excimer laser is lower compared to femtosecond laser. • Effective optical penetration depth for excimer laser is lower compared to femtosecond laser. • Two ablation characteristic regimes are observed for femtosecond laser ablation. • Reduction of C=C bond following excimer or fs laser ablation is observed. • Addition of oxygen- and nitrogen-rich functional groups is observed. - Abstract: This paper presents an investigation on the ablation characteristics of excimer laser (λ = 248 nm, τ = 15 ns) and femtosecond laser (λ = 800 nm, τ = 100 fs) on ABS polymer sheets. The laser–material interaction parameters (ablation threshold, optical penetration depth and incubation factor) and the changes in material chemical properties were evaluated and compared between the two lasers. The work shows that the ablation threshold and effective optical penetration depth values are dependent on the wavelength of laser beam (photon energy) and the pulse width. The ablation threshold value is lower for the excimer laser ablation of ABS (F{sub th} = 0.087 J/cm{sup 2}) than that for the femtosecond laser ablation of ABS (F{sub th} = 1.576 J/cm{sup 2}), demonstrating a more dominating role of laser wavelength than the pulse width in influencing the ablation threshold. The ablation depth versus the logarithmic scale of laser fluence shows two linear regions for the fs laser ablation, not previously known for polymers. The effective optical penetration depth value is lower for excimer laser ablation (α{sup −1} = 223 nm) than that for femtosecond laser ablation (α{sup −1} = 2917 nm). The ablation threshold decreases with increasing number of pulses (NOP) due to the chain scission process that shortens the polymeric chains, resulting in a weaker polymeric configuration and the dependency is governed by the incubation factor. Excimer laser treatment of ABS eliminates the C=C bond completely through the chain scission process whereas C=C bond is partially eliminated through the femtosecond laser treatment due to the difference in photon energy of the two laser beams. A reduction in the C=C bond through the chain scission process creates free radical carbons which then form crosslinks with each other or react with oxygen, nitrogen and water in air producing oxygen-rich (C−O and C=O bond) and nitrogen-rich (C−N) functional groups.

  6. Soft-template hydrothermal systhesis of nanostructured Copper(II) Tungstate cubes for Electrochemical Charge Storage Application

    International Nuclear Information System (INIS)

    Wei, Chao; Huang, Ying; Zhang, Xin; Chen, Xuefang; Yan, Jing

    2016-01-01

    Highlights: • Soft-template hydrothermal method is firstly respoted for CuWO4 samples. • Nano-size distribution of CuWO4 is mainly ascribed to the soft-template of P123. • Excellent performance is due to Low surface energy, blunt edges and active sites. - Abstract: In this work, the soft-template hydrothermal method is firstly applied to synthesize nanocrystal CuWO 4 cubes for the electrode materials in in electrochemical charge storage application. The structures and morphologies of as-obtained materials are characterized via X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The effects of the soft-template (P123) and surfactant (Hexamethylenetetramine) also are verified by the electrochemistry test including CV, GCD, EIS. As a result, the CuWO 4 -PH (synthesis with the assistance of P123 and Hexamethylenetetramine) shows a excellent specific capacitance (C sp ) of 302.40 mAh g −1 at the current density of 1 A g −1 and a good rate capability (60.7% retension rate of original Csp even at 10 A g −1 ), as well as cycle life (82.1% retention rate of original C sp after 2000 cycles). These results reveal that our obtained CuWO 4 -PH could be a promissing electrode material.

  7. Influence of variable tungsten valency on optical transmittance and radiation hardness of lead tungstate (PWO) scintillation crystals

    CERN Document Server

    Burachas, S; Makov, I; Saveliev, Yu; Ippolitov, M S; Man'ko, V; Nikulin, S P; Nyanin, A; Vasilev, A; Apanasenko, A; Tamulaitis, G

    2003-01-01

    A new approach to interpret the radiation hardness of PbWO//4 (PWO) scintillators is developed by revealing importance of the inclusions of tungsten oxides WO//3//-//x with variable valency. It is demonstrated that the influence of the ionizing radiation on PWO is, in many aspects, similar to the effect of the high-temperature annealing in oxygenless ambient. In both cases, a valency change of the tungsten oxides is initiated and results in induced absorption and, consequently, in crystal coloration. In the PWO crystals doped with L//2O//3 (L = Y, La, Gd), the radiation hardness and the optical properties are mainly affected by inclusions of W//1//-//yL//yO//3//- //x (0 less than x less than 0.3) instead of inclusions of WO//3//- //x prevailing in the undoped samples. It is demonstrated that the radiation-induced bleaching and the photochromic effect of PWO are caused by phase transitions in the inclusions of tungsten oxide. Thermodynamic conditions for the phase transitions are discussed and the optimal oxid...

  8. High temperature properties of rare-earth tungstates RE{sub 2}W{sub 2}O{sub 9}

    Energy Technology Data Exchange (ETDEWEB)

    Marrero-López, D., E-mail: damarre@uma.es [Dpto. de Física Aplicada I, Universidad de Málaga, 29071-Málaga (Spain); Canales-Vázquez, J. [Renewable Energy Research Institute, University of Castilla-La Mancha, 02071-Albacete (Spain); Ruiz-Morales, J.C.; Núñez, P. [Dpto. de Química, U.D. Química Inorgánica, Universidad de la Laguna, 38206-Tenerife (Spain)

    2015-02-15

    Highlights: • RE{sub 2}W{sub 2}O{sub 9} (RE = Nd, Pr, Sm, Eu and Gd) are prepared by freeze-drying precursor. • The samples crystallize in the monoclinic s.g. P2{sub 1}/c. • A first order phase transition was detected between 330 and 590 °C. • These materials exhibit low ionic conductivity of 10{sup -5} S cm{sup -1} at 800 °C. - Abstract: RE{sub 2}W{sub 2}O{sub 9} (RE = Ce, Nd, Pr, Sm, Eu, Gd and Tb) compounds have been prepared by a freeze-drying precursor method in order to explore their high temperature thermal properties by different techniques. Samples with Nd, Pr, Sm, Eu and Gd crystallize in the same monoclinic structure with space group P2{sub 1}/c. The thermal, X-ray diffraction, and electrical analysis reveal the existence of a reversible first order phase transition, which is accompanied by a sudden decrease of the unit cell volume and conductivity. A large thermal hysteresis of about 250 °C is also observed during the heating and cooling processes. These materials exhibit low electrical conductivity of the order of 10{sup -5} S cm{sup -1} at 800 °C.

  9. catena-Poly[2-methylpyridinium [tungstate-di-μ-selenido-silver-di-μ-selenido] 2-methylpyridine monosolvate

    Directory of Open Access Journals (Sweden)

    Lu-Jun Zhou

    2013-11-01

    Full Text Available The title compound, {(C6H8N[AgWSe4]·C6H7N}n, consists of anionic [WAgSe4]n chains, 2-methylpyridinium cations and neutral 2-methylpyridine molecules. The Se atoms bridge the Ag and W atoms, forming a polymeric chain extending along the b-axis direction. Both the Ag and W atoms are located on a twofold rotation axis and each metal atom is coordinated by four Se atoms in distorted tetrahedral geometry. In the crystal, the 2-methylpyridinium cation and 2-methylpyridine molecule are linked via N—H...N hydrogen bonding. Weak C—H...Se interactions link the organic components and polymeric anions into a three-dimensional architecture.

  10. High index contrast potassium double tungstate waveguides towards efficient rare-earth ion amplification on-chip

    NARCIS (Netherlands)

    Sefünç, Mustafa; Segerink, Franciscus B.; García Blanco, Sonia Maria

    2015-01-01

    Rare-earth ion doped KY(WO4)2 amplifiers are proposed to be a good candidate for many future applications by benefiting from the excellent gain characteristics of rare-earth ions, namely high bit rate amplification (

  11. Highly efficient channel waveguide lasers at 1 µm and 2 µm in refractive-index-engineered potassium double tungstates

    NARCIS (Netherlands)

    van Dalfsen, Koop; Geskus, D.; García Blanco, Sonia Maria; Pollnau, Markus

    Epitaxial growth of rare-earth-ion-activated KY(1-x-y)Gd(x)Lu(y)(WO4)2 co-doped thin layers onto KY(WO4)2 substrates has enabled lattice-matched waveguides with high refractive-index contract and large variation of the active rare-earth-ion concentration. In Yb3+-activated micro-structured channel

  12. 21 CFR 177.1050 - Acrylonitrile/styrene copoly-mer modified with butadiene/styrene elastomer.

    Science.gov (United States)

    2010-04-01

    ... parts by weight of a grafted rubber consisting of (i) 8-12 parts of butadiene/styrene elastomer... limitations are determined by an infrared spectro-photo-metric method titled “Infrared Spectro-photo-metric...

  13. Recycling cycle of materials applied to acrylonitrile-butadiene-styrene/policarbonate blends with styrene-butadiene-styrene copolymer addition

    Science.gov (United States)

    Cândido, L. H. A.; Ferreira, D. B.; Júnior, W. Kindlein; Demori, R.; Mauler, R. S.

    2014-05-01

    The scope of this research is the recycling of polymers from mobile phones hulls discarded and the performance evaluation when they are submitted to the Recycling Cycle of Materials (RCM). The studied material was the ABS/PC blend in a 70/30 proportion. Different compositions were evaluated adding virgin material, recycled material and using the copolymer SBS as impact modifier. In order to evaluate the properties of material's composition, the samples were characterized by TGA, FTIR, SEM, IZOD impact strength and tensile strength tests. At the first stage, the presented results suggest the composition containing 25% of recycled material and 5% of SBS combines good mechanical performance to the higher content of recycled material and lower content of impact modifier providing major benefits to recycling plans. Five cycles (RCM) were applied in the second stage; they evidenced a decrease trend considering the impact strength. At first and second cycle the impact strength was higher than reference material (ABS/PC blend) and from the fourth cycle it was lower. The superiority impact strength in the first and second cycles can be attributed to impact modifier effect. The thermal tests and the spectrometry didn't show the presence of degradation process in the material and the TGA curves demonstrated the process stability. The impact surface of each sample was observed at SEM. The microstructures are not homogeneous presenting voids and lamellar appearance, although the outer surface presents no defects, demonstrating good moldability. The present work aims to assess the life cycle of the material from the successive recycling processes.

  14. Application of gamma irradiation for incorporation of rubber powder in the formulations of acrylonitrile-butadiene rubber (NBR)

    International Nuclear Information System (INIS)

    Kiyan, Ludmila Y.P.; Parra, Duclerc Fernandes

    2013-01-01

    Full text: Polymeric materials do not decompose easily, disposal of waste polymers is a major environmental problem of global character. Recycling is an economical alternative and environmentally recommended for polymers consumed and discarded by society. As regards the rubber in object, its natural decomposition is much slower due to their highly crosslinked, in three-dimensional networks, structures which makes it an infusible and insoluble material. Moreover, these three dimensional structures entails several problems for their recovery and reprocessing. The aim of this paper was to study the behavior of NBR rubber recycle. It was used rubber powder from industry. The powder was irradiated in master-batch composition and used directly in classical formulations for rubber vulcanization. The master-batch processed was irradiated at doses of 50, 100 and 150kGy in 60 Co source at 5 kGy s -1 rate, at room temperature. Gamma radiation created active sites during devulcanization that promoted further integration of the rubber powder in formulations for commercial use. The processes were compared and their products were characterized by analytical methods of the physical properties such as tensile strength and elongation. The greatest change in the properties of polymeric materials by exposure to ionizing radiation resulted mainly of two main reactions occurring in the polymer molecule: chains scission (degradation) and crosslinking. Although these two processes occur simultaneously in all the polymers, the predominance of one or other effect depends mainly of the chemical structure of each polymer, and the irradiation conditions. In the results was observed the behavior of nitrile rubber under different doses and radiation improvement of the mechanical properties. (author)

  15. Application of gamma irradiation for incorporation of rubber powder in the formulations of acrylonitrile-butadiene rubber (NBR)

    Energy Technology Data Exchange (ETDEWEB)

    Kiyan, Ludmila Y.P.; Parra, Duclerc Fernandes, E-mail: ludmilapozzo@gmail.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Quimica e Meio Ambiente (CQMA)

    2013-07-01

    Full text: Polymeric materials do not decompose easily, disposal of waste polymers is a major environmental problem of global character. Recycling is an economical alternative and environmentally recommended for polymers consumed and discarded by society. As regards the rubber in object, its natural decomposition is much slower due to their highly crosslinked, in three-dimensional networks, structures which makes it an infusible and insoluble material. Moreover, these three dimensional structures entails several problems for their recovery and reprocessing. The aim of this paper was to study the behavior of NBR rubber recycle. It was used rubber powder from industry. The powder was irradiated in master-batch composition and used directly in classical formulations for rubber vulcanization. The master-batch processed was irradiated at doses of 50, 100 and 150kGy in {sup 60}Co source at 5 kGy s{sup -1} rate, at room temperature. Gamma radiation created active sites during devulcanization that promoted further integration of the rubber powder in formulations for commercial use. The processes were compared and their products were characterized by analytical methods of the physical properties such as tensile strength and elongation. The greatest change in the properties of polymeric materials by exposure to ionizing radiation resulted mainly of two main reactions occurring in the polymer molecule: chains scission (degradation) and crosslinking. Although these two processes occur simultaneously in all the polymers, the predominance of one or other effect depends mainly of the chemical structure of each polymer, and the irradiation conditions. In the results was observed the behavior of nitrile rubber under different doses and radiation improvement of the mechanical properties. (author)

  16. Resistivity and Its Anisotropy Characterization of 3D-Printed Acrylonitrile Butadiene Styrene Copolymer (ABS/Carbon Black (CB Composites

    Directory of Open Access Journals (Sweden)

    Jie Zhang

    2017-01-01

    Full Text Available The rapid printing of 3D parts with desired electrical properties enables numerous applications. Fused deposition modeling (FDM using conductive thermoplastic composites has been a valuable approach for such fabrication. The parts produced by FDM possess various controllable structural features, but the effects of the structural features on the electrical properties remain to be determined. This study investigated the effects of these features on the electrical resistivity and resistivity anisotropy of 3D-printed ABS/CB composites. The effects of the process parameters of FDM, including the layer thickness, raster width, and air gap, on the resistivity in both the vertical and horizontal directions for cubic samples were studied because the internal structure of the printed parts depended on those process parameters. The resistivities of printed parts in different parameter combinations were measured by an impedance analyzer and finite element models were created to investigate the relationship between the resistivity and the internal structure. The results indicated that the parameters remarkably affected the resistivity due to the influence of voids and the bonding condition between adjacent fibers. The resistivity in the vertical direction ranged from 70.40 ± 2.88 Ω·m to 180.33 ± 8.21 Ω·m, and the resistivity in the horizontal direction ranged from 41.91 ± 2.29 Ω·m to 58.35 ± 0.61 Ω·m at the frequency of 1 kHz. Moreover, by adjusting the resistivities in different directions, the resistivity anisotropy of the printed parts can be manipulated from 1.01 to 3.59. This research may serve as a reference to fabricate parts with sophisticated geometry with desired electrical resistivity and resistivity anisotropy.

  17. Effect of amine-terminated butadiene-acrylonitrile/clay combinations on the structure and properties of epoxy nanocomposites

    Czech Academy of Sciences Publication Activity Database

    Kelnar, Ivan; Rotrekl, Jakub; Kaprálková, Ludmila; Hromádková, Jiřina; Strachota, Adam

    2012-01-01

    Roč. 125, č. 5 (2012), s. 3477-3483 ISSN 0021-8995 R&D Projects: GA AV ČR IAA200500904 Institutional research plan: CEZ:AV0Z40500505 Keywords : epoxy nanocomposites * mechanical properties * microstructure Subject RIV: JI - Composite Materials Impact factor: 1.395, year: 2012

  18. Benzimidazole acrylonitriles as multifunctional push-pull chromophores: Spectral characterisation, protonation equilibria and nanoaggregation in aqueous solutions

    Science.gov (United States)

    Horak, Ema; Vianello, Robert; Hranjec, Marijana; Krištafor, Svjetlana; Zamola, Grace Karminski; Steinberg, Ivana Murković

    2017-05-01

    Heterocyclic donor-π-acceptor molecular systems based on an N,N-dimethylamino phenylacrylonitrile benzimidazole skeleton have been characterised and are proposed for potential use in sensing applications. The benzimidazole moiety introduces a broad spectrum of useful multifunctional properties to the system including electron accepting ability, pH sensitivity and compatibility with biomolecules. The photophysical characterisation of the prototropic forms of these chromophores has been carried out in both solution and on immobilisation in polymer films. The experimental results are further supported by computational determination of pKa values. It is noticed that compound 3 forms nanoaggregates in aqueous solutions with aggregation-induced emission (AIE) at 600 nm. All the systems demonstrate spectral pH sensitivity in acidic media which shifts towards near-neutral values upon immobilisation in polymer films or upon aggregation in an aqueous environment (compound 3). The structure-property relationships of these functional chromophores, involving their spectral characteristics, acid-base equilibria, pKa values and aggregation effects have been determined. Potential applications of the molecules as pH and biomolecular sensors are proposed based on their pH sensitivity and AIE properties.

  19. Surface properties of poly(acrylonitrile) (PAN) precipitation polymerized in supercritical CO2 and the influence of the molecular weight.

    Science.gov (United States)

    Shen, Qing; Gu, Qing-Feng; Hu, Jian-Feng; Teng, Xin-Rong; Zhu, Yun-Feng

    2003-11-15

    In this paper, the surface properties, e.g., the total surface free energy and the related Lifshitz-van der Waals and Lewis acid-base components, of polyacrylonitrile (PAN) precipitation polymerized in supercritical CO(2) have been characterized. Moreover, the influence of molecular weight varying has been also investigated. Results show that the surface properties of PAN resulting from supercritical CO(2) are different from those obtained by the conventional method. Of these data, one important finding is that the supercritical CO(2) PAN seems to decrease the surface free energy with the increased molecular weight. Based on previous recorded NMR spectra of this PAN and especially compared to commercial PAN, such phenomena are discussed and ascribed to an increase of the H-bonds and a reduction of the isotacticity in the supercritical CO(2) condition for PAN.

  20. THE EFFECTS OF N-2-HYDROXYETHYL-N-METHYL-P-TOLUIDINE ON METHYL METHACRYLATE RADICAL POLYMERIZATION AND ACRYLONITRILE PHOTOINDUCED POLYMERIZATION

    Institute of Scientific and Technical Information of China (English)

    QIU Kunyuan; ZHANG Zhanghua; FENG Xinde

    1992-01-01

    The effects of N-2-hydroxyethyl-N-methyl-p-toluidine (HMT) on MMA polymerization using organic peroxide as an initiator and on AN photoinduced polymerization have been investigated respectively. The kinetics of polymerization and the overall activation energy of polymerization were determined. Based on kinetics study and the end group analysis of the polymer obtained by UV spectrum method, the initiation mechanism is proposed.

  1. Anisotropy and humidity effect on tensile properties and electrical volume resistivity of fused deposition modeled acrylonitrile butadiene styrene composites

    OpenAIRE

    Almenara Cueto, Carlos Ignacio

    2017-01-01

    En la presente tesis, se estudió la influencia de la anisotropía y la humedad en las propiedades mecánicas a la tracción y la resistividad volumétrica de los compuestos de Acrilonitrilo Butadieno Estireno reforzado con Nano Tubos de Carbono y Acrilonitrilo Butadieno Estireno reforzado con Micro Fibras de Carbono impresos en 3D de por Deposición de Material Fundido. Para estudiar la influencia de la anisotropía, tres diferentes orientaciones de impresión de capa fueron compar...

  2. High-resolution measurement and mapping of tungstate in waters, soils and sediments using the low-disturbance DGT sampling technique

    Energy Technology Data Exchange (ETDEWEB)

    Guan, Dong-Xing [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023 (China); Williams, Paul N. [Institute for Global Food Security, School of Biological Sciences, Queen’s University Belfast, Belfast BT9 7BL (United Kingdom); Xu, Hua-Cheng [State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008 (China); Li, Gang [Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Luo, Jun, E-mail: esluojun@nju.edu.cn [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023 (China); Ma, Lena Q. [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023 (China); Soil and Water Science Department, University of Florida, Gainesville, FL 32611 (United States)

    2016-10-05

    Highlights: • Two high-resolution diffusive gradients in thin-films samplers were characterized. • For the first time DGT was applied to study the bioavailability of W in soils. • 1D and 2D high resolution profiling of W fluxes across the SWI were obtained. • The apparent diffusion W fluxes across two micro-interfaces were calculated. - Abstract: Increasing tungsten (W) use for industrial and military applications has resulted in greater W discharge into natural waters, soils and sediments. Risk modeling of W transport and fate in the environment relies on measurement of the release/mobilization flux of W in the bulk media and the interfaces between matrix compartments. Diffusive gradients in thin-films (DGT) is a promising passive sampling technique to acquire such information. DGT devices equipped with the newly developed high-resolution binding gels (precipitated zirconia, PZ, or ferrihydrite, PF, gels) or classic/conventional ferrihydrite slurry gel were comprehensively assessed for measuring W in waters. {sup Ferrihydrite}DGT can measure W at various ionic strengths (0.001–0.5 mol L{sup −1} NaNO{sub 3}) and pH (4–8), while {sup PZ}DGT can operate across slightly wider environmental conditions. The three DGT configurations gave comparable results for soil W measurement, showing that typically W resupply is relatively poorly sustained. 1D and 2D high-resolution W profiling across sediment—water and hotspot—bulk media interfaces from Lake Taihu were obtained using {sup PZ}DGT coupled with laser ablation ICP–MS measurement, and the apparent diffusion fluxes across the interfaces were calculated using a numerical model.

  3. Copper(II) tungstate nanoflake array films: sacrificial template synthesis, hydrogen treatment, and their application as photoanodes in solar water splitting.

    Science.gov (United States)

    Hu, Dianyi; Diao, Peng; Xu, Di; Xia, Mengyang; Gu, Yue; Wu, Qingyong; Li, Chao; Yang, Shubin

    2016-03-21

    We report the preparation of CuWO4 nanoflake (NF) array films by using a solid phase reaction method in which WO3 NFs were employed as sacrificial templates. The SEM, TEM and XRD results demonstrated that the obtained CuWO4 films possessed a network structure that was composed of single crystalline NFs intersected with each other. The CuWO4 NF films showed superior photoelectrochemical (PEC) activity to other CuWO4 photoanodes reported recently for the oxygen evolution reaction (OER). We attributed the high activity to the unique morphological and crystalline structure of the CuWO4 film, which enhanced the photoactivity by providing a large specific area, a short hole transport distance from the inside of CuWO4 to the CuWO4/solution interface, and a low grain boundary density. Hydrogen treatment by annealing the CuWO4 NF film in mixed gases of H2 and Ar could further enhance the photoactivity, as hydrogen treatment significantly increased the electron density of CuWO4 by generating oxygen vacancy in the lattice. The photocurrent density for OER obtained on the hydrogen-treated (H-treated) CuWO4 NF film is the largest ever reported on CuWO4 photoanodes in the literature. Moreover, the CuWO4 photoanodes exhibit good stability in weak alkaline solution, while the H-treated CuWO4 photoanodes exhibit acceptable stability. This work not only reveals the potential of CuWO4 as a photoanode material for solar water splitting but also shows that the construction of nanostructured CuWO4 photoanodes is a promising method to achieve high PEC activity toward OER.

  4. New architectures for integrated optics: low-loss tight bends and on-chip high-index-contrast potassium double Tungstate waveguides

    NARCIS (Netherlands)

    Sefünç, Mustafa

    2016-01-01

    This thesis concentrates on improving the performance of low-index-contrast waveguides in terms of reducing the bend losses and increasing the index contrast of waveguides by heterogeneous adhesive bonding and thinning. In the first part of this thesis, we have demonstrated that introducing a thin

  5. Luminescence and photo-thermally stimulated defect-creation processes in Bi.sup.3+./sup.-doped single crystals of lead tungstate

    Czech Academy of Sciences Publication Activity Database

    Buryi, Maksym; Boháček, Pavel; Chernenko, K.; Krasnikov, A.; Laguta, Valentyn; Mihóková, Eva; Nikl, Martin; Zazubovich, S.

    2016-01-01

    Roč. 123, č. 5 (2016), 895-910 ISSN 0370-1972 R&D Projects: GA ČR GAP204/12/0805 Institutional support: RVO:68378271 Keywords : defects * EPR * excitons * PbWO 4 :Bi single crystals * photoluminescence * thermoluminescence Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.674, year: 2016

  6. Synthesis, characterization and thermal behaviour of cadmium (II) complexes of photosubstituted octacyano-molybdate(IV) and -tungstate(IV) with ethylenediamine

    International Nuclear Information System (INIS)

    Ali, S.I.; Majid, Kowsar

    1998-01-01

    Photosubstituted ethylenediamine complexes of M(CN) 8 4- [where M =Mo(IV) or W(IV)] with cadmium (II) chloride have been synthesized and characterized by infrared (IR), thermogravimetric (TG) and differential scanning calorimetry (DSC). Both Mo(IV) and W(IV) show similar stoichiometric as well as thermal decomposition behaviour. The assigned general formula is Cd[M(CN) 3 (OH)(C 2 H 8 N 2 ) 2 ](C 2 H 8 N 2 ) Cl 2 XH 2 O [where M = Mo(IV) for which X = 1(I) and M = W(IV) for which X = 2 (II)]. The presence of CN - , OH - and C 2 H 8 N 2 has been shown by observed characteristic IR peaks. The extra absorption bands appearing in complex (II) are due to librational modes of water which show the formation of hydrogen bonding, which is also supported by TG analysis. The loss of these absorption bands rules out this type of bonding in (I). Both the complexes decompose in three steps up to 650 degC after which there is no change. DSC of the complexes also shows three transitions, two exothermic and one endothermic. On the basis of TG and DSC thermograms, mechanism for the decomposition of each step has been shown. Kinetic parameters like activation energy (E a ), frequency factor (A) and entropy of activation (ΔS) have been calculated using different integral methods. (author)

  7. Surface of crystallization of K, Rb//Cl, WO4 system

    International Nuclear Information System (INIS)

    Shurdumov, G.K.; Cherkesov, Z.A.; Shurdumov, B.K.

    2000-01-01

    Ternary mutual system of potassium and rubidium chlorides and tungstates is studied by visual-polythermal and differential thermal methods for the first time. It is established that liquidus of the system consists of crystallization fields of continuous double solid solutions on the base of components of binary potassium chloride - rubidium chloride and potassium tungstate - rubidium tungstate systems [ru

  8. Synthesis, crystal structure and aggregation-induced emission of a new pyrene-based compound, 3,3-diphenyl-2-[4-(pyren-1-ylphenyl]acrylonitrile

    Directory of Open Access Journals (Sweden)

    Bao-Xi Miao

    2018-05-01

    Full Text Available The title organic compound, C37H23N, crystallizing in the triclinic space group P\\overline{1}, has been designed, synthesized and characterized by single-crystal X-ray diffaction, MS, NMR and elemental analysis. There are alternating relatively strong and weak intermolecular π–π interactions between adjacent pyrene ring systems, forming a one-dimensional supramolecular structure. The compound is weakly fluorescent in THF solution, but it is highly emissive in the condensed phase, revealing distinct aggregation-induced emission (AIE characteristics.

  9. Morphology and contact angle studies of poly(styrene-co-acrylonitrile modified epoxy resin blends and their glass fibre reinforced composites

    Directory of Open Access Journals (Sweden)

    2007-06-01

    Full Text Available In this study, the surface characteristics of blends and composites of epoxy resin were investigated. Poly(styrene-co-acylonitrile (SAN was used to modify diglycedyl ether of bisphenol-A (DGEBA type epoxy resin cured with diamino diphenyl sulfone (DDS and the modified epoxy resin was used as the matrix for fibre reinforced composites (FRP’s. E-glass fibre was used as the fibre reinforcement. The scanning electron micrographs of the fractured surfaces of the blends and composites were analyzed. Morphological analysis revealed different morphologies such as dispersed, cocontinuous and phase-inverted structures for the blends. Contact angle studies were carried out using water and methylene iodide at room temperature. The solid surface energy was calculated using harmonic mean equations. Blending of epoxy resin increases its contact angle. The surface free energy, work of adhesion, interfacial free energy, spreading coefficient and Girifalco-Good’s interaction parameter were changed significantly in the case of blends and composites. The incorporation of thermoplastic and glass fibre reduces the wetting and hydrophilicity of epoxy resin.

  10. Thermodynamic Compatibility, Crystallizability, Thermal, Mechanical Properties and Oil Resistance Characteristics of Nanostructure Poly (ethylene-co-methyl acrylate/Poly(acrylonitrile-co-butadiene Blends

    Directory of Open Access Journals (Sweden)

    Murugan N.

    2017-12-01

    Full Text Available This paper addresses the compatibility, morphological characteristics, crystallization, physico-mechanical properties and thermal stability of the melt mixed EMA/NBR blends. FTIR spectroscopy reveals considerable physical interaction between the polymers that explain the compatibility of the blends. DSC results confirm the same (compatibility and reveals that NBR hinders EMA crystallization. Mechanical and thermal properties of the prepared EMA/NBR blends notably enhance with increasing the fraction of EMA in the blends. Morphology study exhibit the dispersed particles in spherical shape in the nanometer level. Swelling and oil resistance study have also been carried out in details to understand the performance behaviour of these blends at service condition

  11. Gel electrolytes based on poly(acrylonitrile)/sulpholane with hybrid TiO2/SiO2 filler for advanced lithium polymer batteries

    International Nuclear Information System (INIS)

    Kurc, Beata

    2014-01-01

    Highlights: • Paper describes properties of gel electrolyte based on PAN with TMS and TiO 2 -SiO 2 . • The TiO 2 -SiO 2 oxide composite was precipitated in the emulsion system and used as the fillers. • The capacity of the graphite anode depends on the current rate and the amount of TiO 2 -SiO 2 . • For PE3 electrolyte was obtained practical capacity more than 90% of the theoretical capacity. - Abstract: This paper describes the synthesis and properties of a new type of ceramic fillers for composite polymer gel electrolytes. Hybrid TiO 2 -SiO 2 ceramic powders have been obtained by co-precipitation from titanium(IV) sulfate solution using sodium silicate as the precipitating agent. The resulting submicron-size powders have been applied as fillers for composite polymer gel electrolytes for Li-ion batteries based on polyacrylonitrile (PAN) membranes. The powders and gel electrolytes have been examined structurally and electrochemically, showing favorable properties in terms of electrolyte uptake and electrochemical characteristics in Li-ion cells

  12. Morphology, microstructure and rheological properties of SAN (styrene-acrylonitrile)/EPDM (ethylene-propylene-diene monomer) nanocomposites: Investigating the role of organoclay type and order of mixing

    Energy Technology Data Exchange (ETDEWEB)

    Jeddi, Javad; Yousefzade, Omid [Department of Polymer Engineering and Color Technology, Amirkabir University of Technology, Tehran, 15875-4413 (Iran, Islamic Republic of); Babaei, Amir, E-mail: a.babaei@gu.ac.ir [Polymer Engineering Department, Faculty of Engineering, Golestan University, 4918888369, Gorgan (Iran, Islamic Republic of); Ghanbar, Sadegh; Rostami, Amir [Department of Polymer Engineering and Color Technology, Amirkabir University of Technology, Mahshahr Campus, Mahshahr, 6351716178 (Iran, Islamic Republic of)

    2017-02-01

    The object of this work was to investigate the preferential localization of nanoclay platelets in SAN/EPDM (80/20) blend in terms of thermodynamic and kinetic considerations. In this way, effects of two organoclay types and mixing sequences on the morphology, microstructure and rheological properties of prepared blends were studied. Calculations based on the thermodynamic point of view suggested both nanoclay types should be localized in the SAN phase. The XRD results demonstrated that SAN phase as a matrix played a more significant role in the intercalation/exfoliation of organoclays rather than dispersed EPDM phase. Linear viscoelastic studies showed a high tendency for both of organoclays to be localized in the SAN component as well as better dispersion state of cloisite 30B organoclay. The results of creep and creep-recovery experiments revealed the reversible deformation of nanocomposites decreased with increasing degree of organoclay dispersion. The calculated retardation spectrums indicated the dominant role of filler – filler interaction on the melt viscoelastic response of ternary nanocomposites. In addition, scanning electron microscopy (SEM) was employed to study the correlation between the rheological properties, and microstructure and morphological features of blends. - Highlights: • SAN/EPDM/organoclay nanocomposite was prepared with different mixing sequences. • The location of organoclay in SAN/EPDM blend controlled by thermodynamic parameters. • The dispersed phase size decreased in presence of organoclay. • Correlation between rheological properties and microstructure has been established.

  13. On tungstates of divalent cations (I). Structural investigation and spectroscopic properties of Sr{sub 2}[WO{sub 5}] and Ba{sub 2}[WO{sub 5}

    Energy Technology Data Exchange (ETDEWEB)

    Jantz, Stephan G.; Dialer, Marwin; Hoeppe, Henning A. [Lehrstuhl fuer Festkoerperchemie, Universitaet Augsburg (Germany); Pielnhofer, Florian [Abteilung Nanochemie, Max-Planck-Institut fuer Festkoerperforschung, Stuttgart (Germany)

    2017-12-13

    The crystal structures of Sr{sub 2}[WO{sub 5}] [Pna2{sub 1}, a = 7.2457(3) Aa, b = 10.8867(5) Aa, c = 5.5391(3) Aa, Z = 4, R{sub int} = 0.0671, R{sub 1} = 0.0495, wR{sub 2} = 0.0462] and Ba{sub 2}[WO{sub 5}] [Pnma, a = 7.3828(2) Aa, b = 5.71420(10) Aa, c = 11.4701(3) Aa, Z = 4, R{sub int} = 0.0294, R{sub 1} = 0.0146, wR{sub 2} = 0.0284] are revised, based on single-crystal XRD data. Furthermore spectroscopic data (infrared, Raman, and UV/Vis) assisted by DFT calculations are discussed and first results on the luminescence properties of Sr{sub 2}[WO{sub 5}]:Eu{sup 3+} are presented. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  14. catena-Poly[[tetrakis(hexamethylphosphoramide-κObis(nitrato-κ2O,O′lanthanum(III] [silver(I-di-μ2-sulfido-tungstate(VI-di-μ2-sulfido

    Directory of Open Access Journals (Sweden)

    Lude Lu

    2008-02-01

    Full Text Available Hexamethylphosphoramide (hmp, tetrathiotungstate(VI, silver sulfide and lanthanum(III nitrate are self-assembled to form discrete cations one-dimensional poylmeric anionic chains [AgWS4]nn− in the title compound, {[La(NO32(C6H18N3OP4][AgWS4]}n. The central La atom in the cation is coordinated by eight O atoms from two nitrate and four hmp ligands. Together with the two nitrate ligands, the cation is monovalent, which leads to the anionic chain having a monovalent repeat unit. The polymeric anionic chain with W...Ag...W and Ag...W...Ag angles of 165.94 (3 and 155.894 (14° presents a distorted linear configuration. Five N atoms, 18 C atoms and their attached H atoms are disordered equally over two positions.

  15. Effect of the particle size and surface area of tungstated zirconia on the WOx nuclearity and n-heptane isomerization over Pt/WO3–ZrO2

    Czech Academy of Sciences Publication Activity Database

    Kaucký, Dalibor; Wichterlová, Blanka; Dědeček, Jiří; Sobalík, Zdeněk; Jakubec, Ivo

    2011-01-01

    Roč. 397, 1-2 (2011), s. 82-93 ISSN 0926-860X R&D Projects: GA AV ČR KAN100400702 Institutional research plan: CEZ:AV0Z40320502; CEZ:AV0Z40400503 Keywords : n-heptane isomeration * Pt/WO3-ZrO2 * nano ZrO2 Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.903, year: 2011

  16. The system NaVO3-Na2WO4-Na2W2O7

    International Nuclear Information System (INIS)

    Kazanbekov, V.R.; Gasanaliev, A.M.; Kazanbekov, R.G.

    1994-01-01

    Phase diagrams of sodium metavanadate-sodium ditungstate, sodium metavanadate-sodium tungstate systems and surface of primary crystallization of sodium metavabadate-sodium tungstate-sodium ditungstate system were studied. The system sodium metavanadate-sodium ditungstate is eutectic one. Compound NaVO 3 x2Na 2 WO 4 is formed in solid state in sodium metavanadate-sodium tungstate system. Liquidus surface of sodium metavanadate-sodium tungstate-sodium ditungstate is presented by three crystallization fields of initial components. Composition and melting point of ternary eutectics are determined

  17. Syngas conversion to a light alkene and related methods

    Science.gov (United States)

    Ginosar, Daniel M.; Petkovic, Lucia M.

    2017-11-14

    Methods of producing a light alkene. The method comprises contacting syngas and tungstated zirconia to produce a product stream comprising at least one light alkene. The product stream is recovered. Methods of converting syngas to a light alkene are also disclosed. The method comprises heating a precursor of tungstated zirconia to a temperature of between about 350.degree. C. and about 550.degree. C. to form tungstated zirconia. Syngas is flowed over the tungstated zirconia to produce a product stream comprising at least one light alkene and the product stream comprising the at least one light alkene is recovered.

  18. Phase II Tungsten Fate-and Transport Study for Camp Edwards

    Science.gov (United States)

    2010-02-01

    cubic meters degrees Fahrenheit (oF-32)/1.8 degrees Celsius (oC) feet 0.3048 meters gallons (U.S. liquid) 3.785412 E-03 liters inches 0.0254 meters...1 Desorption/dissolution of tungsten 451 39 8.1 2 Sorption of sodium tungstate and desorption/dissolution of tungsten and sodium tungstate 124

  19. Process for the graft polymerization of polyvinyl chloride. [electron beams

    Energy Technology Data Exchange (ETDEWEB)

    Kageyama, E; Kusama, Y; Udagawa, A; Hashimoto, S

    1970-08-14

    The graft polymerization of acrylonitrile on polyvinyl chloride is effected by simultaneous irradiation with ionizing radiations in a reaction bath consisting of 30% acrylonitrile and 70% n-hexane. The acrylonitrile-hydrocarbon reaction bath increases the graft efficiency markedly when the content of acrylonitrile is 30%. In this case, the formation rate of acrylonitrile homopolymer decreases with a decrease in the content of acrylonitrile. The immersion time may be from a few minutes to a few hours, depending on the type, property and desired graft efficiency of the polyvinyl chloride resin. The polyvinyl chloride may be any available on the market. The acrylonitrile may contain a small quantity of copolymerizable monomer if it does not influence the thermal property of the polyvinyl chloride graft polymer. The ionizing radiations must have enough energy to form an ion pair by removing one electron from one atom of a gas. In examples, 10 g of polyvinyl chloride in powder form were immersed in 100 cc of a mixed solution consisting of 70% to 90% of n-hexane and 10% to 30% of acrylonitrile. The polyvinyl chloride in the solution was exposed to electron beams of 2 Mrad at a dose rate of 7.2 x 10/sup 7/ rad/hr. under a reduced pressure. The graft efficiency was 50% to 80% and the yield of acrylonitrile homopolymer was 0.42 g to 1.26 g.

  20. Synthesis, characterization and ion exchange properties of ...

    Indian Academy of Sciences (India)

    sodium tungstate, potassium iodate and 1 mol L–1 orthophosphoric acid to aqueous ... titration, Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis. ..... moderate concentration whereas it is less stable in bases.

  1. Impurity-doped micro-lasers

    NARCIS (Netherlands)

    Pollnau, Markus

    2013-01-01

    Recently rare-earth-ion-doped dielectric channel waveguides have proven their ability to generate highly efficient laser output in the fundamental mode. Here we review our recent achievements obtained in crystalline potassium double tungstates and amorphous aluminum oxide.

  2. Chromatographic separation of low-temperature tar. Part II

    Energy Technology Data Exchange (ETDEWEB)

    Terres, E; Gebert, F; Huelsemann, H; Petereit, H; Toepsch, H; Ruppert, W

    1955-01-01

    Chromatographic methods and apparatus are discussed. The Folin-Denis reagent (Na tungstate molybdate in H/sub 3/PO/sub 4/) is used for developing paper chromatograms of phenol mixtures. Other reagents are given.

  3. Alkenenitrile Transmissive Olefination: Synthesis of the Putative Lignan "Morinol I"

    Science.gov (United States)

    Fleming, Fraser F.; Liu, Wang; Yao, Lihua; Pitta, Bhaskar; Purzycki, Matthew; Ravikumar, P. C.

    2012-01-01

    Grignard reagents trigger an addition-elimination with α'-hydroxy acrylonitriles to selectively generate Z-alkenenitriles. The modular assembly of Z-alkenenitriles from a Grignard reagent, acrylonitrile, and an aldehyde is ideal for stereoselectively synthesizing alkenes as illustrated in the synthesis of the putative lignan "morinol I." PMID:22545004

  4. A study of electron excitations in CaWO sub 4 and PbWO sub 4 single crystals

    CERN Document Server

    Muerk, V; Mihoková, E; Nitsch, K

    1997-01-01

    The excitation spectra of photo- and thermo-luminescence were compared in the VUV-UV spectral region in CaWO sub 4 and PbWO sub 4 scheelite tungstates. Temperature dependences of emission intensities and decay times were measured for PbWO sub 4 in the 80-300 K range and approximated by a simple phenomenological model. The energy level structure of the emission centre excited state and related kinetic processes are discussed for both tungstates. (author)

  5. Purification and characterization of acetylene hydratase of Pelobacter acetylenicus, a tungsten iron-sulfur protein

    OpenAIRE

    Rosner, Bettina M.; Schink, Bernhard

    1995-01-01

    Acetylene hydratase of the mesophilic fermenting bacterium Pelobacter acetylenicus catalyzes the hydration of acetylene to acetaldehyde. Growth of P. acetylenicus with acetylene and specific acetylene hydratase activity depended on tungstate or, to a lower degree, molybdate supply in the medium. The specific enzyme activity in cell extract was highest after growth in the presence of tungstate. Enzyme activity was stable even after prolonged storage of the cell extract or of the purified prote...

  6. Separation of caesium-137 from fission products using phosphotungstic acid

    International Nuclear Information System (INIS)

    Murthy, T.S.; Balasubramaniam, K.R.; Ananthakrishnan, M.; Varma, R.N.

    1977-01-01

    Separation of caesium 137 from fission products using phosphotungstic acid is reported. Phosphotungstate caesium is precipitated as caesium from fission product waste solution in acid medium and subsequently purified. Separation of phosphate and tungstate ions has been done using a typical hydrous oxide like alumina. The exchange capacity of alumina for phosphate and tungstate ions, and the purity of the product are determined. Results are discussed. Based on the findings a procedure is recommended for caesium 137 separation. (A.K.)

  7. Pengaruh suhu vulkanisasi terhadap sifat mekanis vulkanisat karet alam dan karet akrilonitril-butadiena

    Directory of Open Access Journals (Sweden)

    Norma Arisanti Kinasih

    2015-12-01

    Full Text Available Natural and acrylonitrile-butadiene rubbers possess different vulcanization characteristics. Selection of the vulcanization system and temperature affects the mechanical properties of vulcanized natural rubber (NR and acrylonitrile-butadiene rubber (NBR. In the present work, the effect of vulcanization temperature (150, 160, 170 and 180oC on the mechanical properties of NR and NBR vulcanizates was studied. The effect of different vulcanization system (semi efficient, efficient and sulfur donor was studied in NR blends, while the effect of different acrylonitrile content (26, 28 and 33 wt % was studied in NBR blends. The NBR curing characteristics and mechanical properties data showed that vulcanization at low temperature (150oC was suitable for low acrylonitrile-NBR, whereas that at high temperature (170oC was suitable for high acrylonitrile-NBR. In addition, the semi efficient system at low temperature vulcanization (150oC was suitable for natural rubber.

  8. Nitrile rubber and carboxylated nitrile rubber resistance to soybean biodiesel

    Directory of Open Access Journals (Sweden)

    Felipe Nunes Linhares

    2018-03-01

    Full Text Available Abstract Biodiesel has been considered a suitable substitute for petroleum diesel, but their chemical composition differs greatly. For this reason, biodiesel interacts differently than petroleum diesel with various materials, including rubbers. Therefore, the resistance of some elastomers should be thoroughly evaluated, specifically those which are commonly used in automotive industry. Nitrile rubber (NBR is widely used to produce vehicular parts that are constantly in contact with fuels. This paper aimed to assess the resistance of carboxylated nitrile rubber (XNBR with 28% of acrylonitrile content to soybean biodiesel in comparison with non-carboxylated nitrile rubber samples, with high and medium acrylonitrile content (33 and 45%. NBR with medium acrylonitrile content showed little resistance to biodiesel. However, carboxylated nitrile rubber even with low acrylonitrile content had similar performance to NBR with high acrylonitrile content.

  9. Dispersion and consolidation of WO{sub x}-doped zirconia from zirconium tungstate and triethanolamine in aqueous medium; Dispersao e consolidacao de zirconia dopada com WO{sub x} a partir do tungstato de zirconio e trietanolamina em meio aquoso

    Energy Technology Data Exchange (ETDEWEB)

    Antunes, M.; Zorzi, J.E.; Perottoni, C.A., E-mail: jezorzi@ucs.br [Universidade de Caxias do Sul (UCS), RS (Brazil); Machado, G. [Centro de Tecnologias Estrategicas do Nordeste, Recife, PE (Brazil)

    2017-01-15

    In recent studies, it was possible to produce hydrous zirconia nanoparticles with crystallite sizes as small as 2 nm from ZrW{sub 2} O{sub 8} powder with initial particle size of 1.7 μm in an aqueous medium. The zirconia nanoparticles formed transparent polycrystalline aggregates. However, the controlled production of transparent zirconia solids by centrifugation of stable suspensions, deagglomerated in the moment of the synthesis, has not been explored yet. In this context, this study aimed to evaluate the dispersion and consolidation of hydrous zirconia nanoparticles produced from ZrW{sub 2} O{sub 8} , in aqueous medium and using triethanolamine (TEOA) as surfactant, and to understand the effect of experimental conditions on the tungsten content in the consolidated solids. The synthesis and dispersion were carried out in aqueous medium at 80 °C with the use of NaOH and TEOA; the colloidal solutions were dialysed, their pH values were adjusted to 6, and then ultracentrifuged at 28000 rpm for 24 h. It has been found that the use of TEOA in the synthesis allowed obtaining stable sols of zirconia nanoparticles which, after centrifugation, originated transparent and yellowish solids that were characterized using various techniques (scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction, Raman spectroscopy, Fourier transform infrared spectroscopy, and simultaneous thermal analysis). Although TEOA assists in the dispersion of nanoparticles, it interfered in the synthesis mechanism, leading to the production of zirconia doped with WO{sub x} , with tungsten concentrations that varied depending on the experimental conditions employed. (author)

  10. Determination and modeling for the solubility of Na_2WO_4·2H_2O and Na_2MoO_4·2H_2O in the (Na"+ + MoO_4"2"− + WO_4"2"− + SO_4"2"− + H_2O) system

    International Nuclear Information System (INIS)

    Ning, Pengge; Xu, Weifeng; Cao, Hongbin; Xu, Hongbin

    2016-01-01

    Highlights: • The solubility of Na_2MoO_4·2H_2O and Na_2WO_4·2H_2O in Na_2MoO_4–Na_2WO_4–Na_2SO_4–H_2O were performed. • The solubility of sodium tungstate dihydrate in Na_2WO_4–Na_2SO_4–H_2O was determined. • The new model was established via regressing the published and the determined data. • The Pitzer parameter and the solubility product constant of the salt in solution were calculated. • The model was used to estimate the solubility of the sodium molybdate and sodium tungstate. - Abstract: The solubility of sodium tungstate dihydrate and sodium molybdate dihydrate in the (Na_2MoO_4 + Na_2WO_4 + Na_2SO_4 + H_2O) system was studied using experimental and calculated methods. The osmotic coefficient of sodium tungstate was fitted to calculate the thermodynamics parameters of (Na_2WO_4 + H_2O) system. The solubility of sodium tungstate dihydrate was determined using the dynamic method in Na_2WO_4–Na_2SO_4–H_2O to establish the new model which can provide an estimate the solubility of sodium tungstate dihydrate in various conditions, combined with the data published, the solubility of sodium tungstate dihydrate and the sodium molybdate dihydrate in quaternary system of (Na_2MoO_4 + Na_2WO_4 + Na_2SO_4 + H_2O) was estimated using the parameters of the two ternary systems of (Na_2WO_4 + Na_2SO_4 + H_2O) and (Na_2MoO_4 + Na_2SO_4 + H_2O). The results show that the AARD is always small and the calculated value is basically consistent with the experimental values for the system studied.

  11. Alternative Fuels Compatibility with Army Equipment Testing - Alternative Fuels Material Compatibility Analysis

    Science.gov (United States)

    2012-02-21

    96906) 5330-00-182-3170 O-ring Butadiene-acrylonitrile class NBR AAFARS 13217E5363 (97403) 5330-00-235-4716 Gasket, Sight Gauge Rubber synthetic...Butadiene-acrylonitrile class NBR FSSP 13216E8238 (97403) 5330-00-647-2072 Gasket Rubber synthetic AAFARS MS28774-017 (96906) 5330-00-833-4210 Back...ring Butadiene-acrylonitrile class NBR AAFARS 5331-00-641-1119 O-ring Rubber synthetic AAFARS M25988/1-017 (81349) 5331-00-759-2121 O-ring

  12. Use of ion exchange during preparation of raw materials for production of molybdenum and tungsten of high purify

    International Nuclear Information System (INIS)

    Blokhin, A.A.; Rumyantsev, V.K.; Taushkanov, V.P.; Maksimkov, S.M.; Majorov, D.Yu.; Pak, V.I.

    1988-01-01

    The data on the application of selective ionites for the steep purification of ammonium molybdate and tungstate solutions, are given. It is shown that to purify molybdenum and ammonium tungstate solutions from the impuerities of alkali earth and two- and threevalent transition metals, iminodiacetate ampholites of the ANKB-35 type are the most effective sorbents. To purify from phosphorus, silicon and arsenic impurities composition ionites on the base of hydrated oxides of multivalent metals introduced in the granules of porous cationites should be used. To extract phosphorus, silicon, arsenic impurities from ammonium molybdate and tungstate solutions and tungsten from ammonium molybdate solutions the method of their coprecipitation with iron (3) hydroxide can also be used. The best results on the purification of ammonium molybdate from tungstate provides for the application of structural organomineral ionites as well as weak-basicity anionites of the AN-31 type and its different modifications containing hydroxyl groups along with aminogroups. To purity ammonium tungstate solutions from molybdate a method is developed which transforms molybdenum in the form of thiocomplexes and the following selective sorption by strong-basicity anionites. The data on the quality of molybdenum monocrystals which are taken from the raw material purified using ionites, are given

  13. Preliminary study on radiation crosslinking of PE-NBR multiple phase system

    International Nuclear Information System (INIS)

    Wang Hong; Zhang Wanxi; Sun Jiazhen

    1989-01-01

    The effect of radiation crosslinking on the structure and properties of PE-NBR (polyethylene-acrylonitrile-butadiene rubber) multiple phase system was studied in this paper. The relationship of sol fraction and irradiated dose to multiplephase system was demonstrated

  14. Recycling of engineering plastics from waste electrical and electronic equipments: influence of virgin polycarbonate and impact modifier on the final performance of blends.

    Science.gov (United States)

    Ramesh, V; Biswal, Manoranjan; Mohanty, Smita; Nayak, Sanjay K

    2014-05-01

    This study is focused on the recovery and recycling of plastics waste, primarily polycarbonate, poly(acrylonitrile-butadiene-styrene) and high impact polystyrene, from end-of-life waste electrical and electronic equipments. Recycling of used polycarbonate, acrylonitrile-butadiene-styrene, polycarbonate/acrylonitrile-butadiene-styrene and acrylonitrile-butadiene-styrene/high impact polystrene material was carried out using material recycling through a melt blending process. An optimized blend composition was formulated to achieve desired properties from different plastics present in the waste electrical and electronic equipments. The toughness of blended plastics was improved with the addition of 10 wt% of virgin polycarbonate and impact modifier (ethylene-acrylic ester-glycidyl methacrylate). The mechanical, thermal, dynamic-mechanical and morphological properties of recycled blend were investigated. Improved properties of blended plastics indicate better miscibility in the presence of a compatibilizer suitable for high-end application.

  15. Elastomers for Tracked Vehicles: 1980-1997 Program to Improve Durability of Rubber Tank Pads for Army Tracked Vehicles

    Science.gov (United States)

    2015-06-01

    elastomeric compound coded NBR -12 was developed. This compound was based on a highly saturated nitrile rubber or hydrogenated acrylonitrile-butadiene...at Fort Belvoir, VA, produced a patented rubber formulation ( NBR -12) based on hydrogenated nitrile rubber (HNBR)1,2 with a novel curing and filler...performance vehicles. • Acrylonitrile butadiene or nitrile rubber ( NBR )10: NBR is the generic name given to emulsion polymerized copolymers of

  16. Pengaruh suhu vulkanisasi terhadap sifat mekanis vulkanisat karet alam dan karet akrilonitril-butadiena

    OpenAIRE

    Norma Arisanti Kinasih; Muhammad Irfan Fathurrohman; Dadang Suparto

    2015-01-01

    Natural and acrylonitrile-butadiene rubbers possess different vulcanization characteristics. Selection of the vulcanization system and temperature affects the mechanical properties of vulcanized natural rubber (NR) and acrylonitrile-butadiene rubber (NBR). In the present work, the effect of vulcanization temperature (150, 160, 170 and 180oC) on the mechanical properties of NR and NBR vulcanizates was studied. The effect of different vulcanization system (semi efficient, efficient and sulfur d...

  17. Styrene-Based Copolymer for Polymer Membrane Modifications

    OpenAIRE

    Harsha Srivastava; Harshad Lade; Diby Paul; G. Arthanareeswaran; Ji Hyang Kweon

    2016-01-01

    Poly(vinylidene fluoride) (PVDF) was modified with a styrene-based copolymer. The crystalline behavior, phase, thermal stability, and surface morphology of the modified membranes were analyzed. The membrane surface roughness showed a strong dependence on the styrene-acrylonitrile content and was reduced to 34% for a PVDF/styrene-acrylonitrile blend membrane with a 40/60 ratio. The thermal and crystalline behavior confirmed the blend miscibility of both polymers. It was observed in X-ray diffr...

  18. Advances in propane ammoxidation catalyst technology

    Energy Technology Data Exchange (ETDEWEB)

    Prada Silvy, R.; Grange, P. [Unite de Catalyse et Chimie des Materiaux Divises, Univ. Cathologique de Louvain, Louvain-la-Neuve (Belgium)

    2003-09-01

    Comparison of the catalytic performance of different propane ammoxidation catalyst systems from the patent literature is established in order to identify the most promising formulation towards process commercialization scale. Vanadium aluminum oxynitride material shows the highest acrylonitrile production level per hour and per amount of catalyst with respect to conventional vanadium-molybdate and vanadium- antimonate mixed oxide propane ammoxidation systems. Acrylonitrile, hydrogen cyanide and acetonitrile production from propane ammoxidation is the key factor for obtaining competitive advantages over current propylene technology. (orig.)

  19. Melt processing and property testing of a model system of plastics contained in waste from electrical and electronic equipment.

    Science.gov (United States)

    Triantou, Marianna I; Tarantili, Petroula A; Andreopoulos, Andreas G

    2015-05-01

    In the present research, blending of polymers used in electrical and electronic equipment, i.e. acrylonitrile-butadiene-styrene terpolymer, polycarbonate and polypropylene, was performed in a twin-screw extruder, in order to explore the effect process parameters on the mixture properties, in an attempt to determine some characteristics of a fast and economical procedure for waste management. The addition of polycarbonate in acrylonitrile-butadiene-styrene terpolymer seemed to increase its thermal stability. Also, the addition of polypropylene in acrylonitrile-butadiene-styrene terpolymer facilitates its melt processing, whereas the addition of acrylonitrile-butadiene-styrene terpolymer in polypropylene improves its mechanical performance. Moreover, the upgrading of the above blends by incorporating 2 phr organically modified montmorillonite was investigated. The prepared nanocomposites exhibit greater tensile strength, elastic modulus and storage modulus, as well as higher melt viscosity, compared with the unreinforced blends. The incorporation of montmorillonite nanoplatelets in polycarbonate-rich acrylonitrile-butadiene-styrene terpolymer/polycarbonate blends turns the thermal degradation mechanism into a two-stage process. Alternatively to mechanical recycling, the energy recovery from the combustion of acrylonitrile-butadiene-styrene terpolymer/polycarbonate and acrylonitrile-butadiene-styrene terpolymer/polypropylene blends was recorded by measuring the gross calorific value. Comparing the investigated polymers, polypropylene presents the higher gross calorific value, followed by acrylonitrile-butadiene-styrene terpolymer and then polycarbonate. The above study allows a rough comparative evaluation of various methodologies for treating plastics from waste from electrical and electronic equipment. © The Author(s) 2015.

  20. Titrimetric determination of tungsten in its alloys with tantalum

    International Nuclear Information System (INIS)

    Elinson, S.V.; Nezhnova, T.I.

    1982-01-01

    Titrimetric method of tungsten determination in tantalum base alloys has been developed. The method permits to determine 5-10% tungsten in the alloys with relative standard deviation of 0.013. The conditions are created by application of precipitation from homogeieous solutions or by the method of appearing reagents at pH values, which condition gradual hydrolytic precipitation of tantalum, and sodium tungstate remains in the solution and is not sorbed on tantalum hydroxide. After separation of tantalum oxide tungsten is precipitated in the form of lead tungstate by the excess of ti trated solution of lead salt during boiling and then at the background of lead tungstate precipitate without its separation lead excess is titrated by EDTA in the presence of mixed indicator-4-(2-pyridylazo)resocinol and xylenole orange in acetate buffer solution

  1. Eu-activated fluorochlorozirconate glass-ceramic scintillators

    International Nuclear Information System (INIS)

    Johnson, J. A.; Schweizer, S.; Henke, B.; Chen, G.; Woodford, J.; Newman, P. J.; MacFarlane, D. R.

    2006-01-01

    Rare-earth-doped fluorochlorozirconate (FCZ) glass-ceramic materials have been developed as scintillators and their properties investigated as a function of dopant level. The paper presents the relative scintillation efficiency in comparison to single-crystal cadmium tungstate, the scintillation intensity as a function of x-ray intensity and x-ray energy, and the spatial resolution (modulation transfer function). Images obtained with the FCZ glass-ceramic scintillator and with cadmium tungstate are also presented. Comparison shows that the image quality obtained using the glass ceramic is close to that from cadmium tungstate. Therefore, the glass-ceramic scintillator could be used as an alternative material for image formation resulting from scintillation. Other inorganic scintillators such as single crystals or polycrystalline films have limitations in resolution or size, but the transparent glass-ceramic can be scaled to any shape or size with excellent resolution

  2. Classification of a Haemophilus influenzae ABC Transporter HI1470/71 through Its Cognate Molybdate Periplasmic Binding Protein, MolA

    Energy Technology Data Exchange (ETDEWEB)

    Tirado-Lee, Leidamarie; Lee, Allen; Rees, Douglas C.; Pinkett, Heather W. (CIT); (NWU)

    2014-10-02

    molA (HI1472) from H. influenzae encodes a periplasmic binding protein (PBP) that delivers substrate to the ABC transporter MolB{sub 2}C{sub 2} (formerly HI1470/71). The structures of MolA with molybdate and tungstate in the binding pocket were solved to 1.6 and 1.7 {angstrom} resolution, respectively. The MolA-binding protein binds molybdate and tungstate, but not other oxyanions such as sulfate and phosphate, making it the first class III molybdate-binding protein structurally solved. The {approx}100 {mu}M binding affinity for tungstate and molybdate is significantly lower than observed for the class II ModA molybdate-binding proteins that have nanomolar to low micromolar affinity for molybdate. The presence of two molybdate loci in H. influenzae suggests multiple transport systems for one substrate, with molABC constituting a low-affinity molybdate locus.

  3. Structure–acidity correlation of supported tungsten(VI)-oxo-species: FT-IR and TPD studies of adsorbed pyridine and catalytic decomposition of 2-propanol

    Energy Technology Data Exchange (ETDEWEB)

    Zaki, M.I., E-mail: mizaki@mu.edu.eg; Mekhemer, G.A.H.; Fouad, N.E.; Rabee, A.I.M.

    2014-07-01

    The amount of 10 wt%-WO{sub 3} was supported on alumina, titania or silica by impregnation with aqueous solution of ammonium paratungstate and subsequent calcination at 500 °C for 10 h. Tungstate-related chemical and physical changes in the calcination products were resolved by ex-situ infrared (IR) spectroscopy. Nature of exposed surface acid sites were probed by in-situ IR spectroscopy of adsorbed pyridine (Py) molecules at room temperature (RT). The relative strength of the acid sites thus probed was gauged by combining results of temperature-programmed desorption (TPD) measurements of the RT-adsorbed Py with those communicated by in-situ IR spectra of residual Py on the surface after a brief thermoevacuation at high temperatures (100–300 °C). Reactivity of the surface acid sites was tested toward 2-propanal catalytic decomposition, and observed by in-situ IR gas phase spectra. Results obtained were correlated with predominant structures assumed by the supported tungstate species. Accordingly, polymerization of the supported tungstate into 2-/3-dimensional structures, was found to be relatively most advanced on favorable locations of titania surfaces as compared to the case on alumina or silica surfaces. Consequently, the Lewis acidity was strengthened, and strong Bronsted acidity was evolved, leading to a 2-propanol dehydration catalyst (tungstate/titania) of optimal activity and selectivity. Strong tungstate/support interfacial interactions were found to hamper the formation of the strongly acidic and catalytically active polymeric structures of the supported tungstate (i.e., the case on alumina or silica).

  4. Structure–acidity correlation of supported tungsten(VI)-oxo-species: FT-IR and TPD studies of adsorbed pyridine and catalytic decomposition of 2-propanol

    International Nuclear Information System (INIS)

    Zaki, M.I.; Mekhemer, G.A.H.; Fouad, N.E.; Rabee, A.I.M.

    2014-01-01

    The amount of 10 wt%-WO 3 was supported on alumina, titania or silica by impregnation with aqueous solution of ammonium paratungstate and subsequent calcination at 500 °C for 10 h. Tungstate-related chemical and physical changes in the calcination products were resolved by ex-situ infrared (IR) spectroscopy. Nature of exposed surface acid sites were probed by in-situ IR spectroscopy of adsorbed pyridine (Py) molecules at room temperature (RT). The relative strength of the acid sites thus probed was gauged by combining results of temperature-programmed desorption (TPD) measurements of the RT-adsorbed Py with those communicated by in-situ IR spectra of residual Py on the surface after a brief thermoevacuation at high temperatures (100–300 °C). Reactivity of the surface acid sites was tested toward 2-propanal catalytic decomposition, and observed by in-situ IR gas phase spectra. Results obtained were correlated with predominant structures assumed by the supported tungstate species. Accordingly, polymerization of the supported tungstate into 2-/3-dimensional structures, was found to be relatively most advanced on favorable locations of titania surfaces as compared to the case on alumina or silica surfaces. Consequently, the Lewis acidity was strengthened, and strong Bronsted acidity was evolved, leading to a 2-propanol dehydration catalyst (tungstate/titania) of optimal activity and selectivity. Strong tungstate/support interfacial interactions were found to hamper the formation of the strongly acidic and catalytically active polymeric structures of the supported tungstate (i.e., the case on alumina or silica).

  5. A comparative study of CaWO4 and rare earth intensifying screens

    International Nuclear Information System (INIS)

    Ambiger, T.Y.; Ayappan, P.

    1978-01-01

    Three brands of commercially available calcium tungstate intensifying screens and a brand of rare earth screen emitting blue light have been used with two types of fast medical x-ray films, one imported and the other indigenous in various film-screen combinations and their sensitometric properties have been determined and compared. The rare earth screen has been found to be about 3 to 4 times faster than the tungstate screens without reduction in contrast. This indicates that the use of rare earth screen in medical radiography will help to reduce the patient dose by the same factor. (M.G.B.)

  6. Systematic Study of the PbWO4 Crystal Short Term Instalibity Under Irradiation

    CERN Document Server

    Annenkov, Alexander; Chipaux, Rémi; Drobychev, Gleb; Fedorov, Andrey; Géléoc, Marie; Golubev, Nikolai; Korzhik, Mikhail; Lecoq, Paul; Ligun, A B; Missevitch, Oleg; Pavlenko, V B; Peigneux, Jean-Pierre; Singovsky, Alexander

    1997-01-01

    The effect of the irradiation on the lead tungstate ( PWO) scintillator properties has been studied at different irradiation facilities. Lead tungstate crystals grown with the tuning of oxides content in the melt to the stoichiometry of pure sheelite or sheelite-like type crystals and doped with heterovalent, trivalent and pentavalent impurities have been studied in order to optimize their resistance to irradiation. A combination of a selective cleaning of raw materials, a tuning of the melt from crystallization to crystallisation, and a destruction or compensation of the point structure defects has been used to minimize the short-term instability of PWO parameters under irradiation.

  7. Systematic study of the short-term instability of PbWO4 scintillator parameters under irradiation

    International Nuclear Information System (INIS)

    Annenkov, A.N.; Ligun, A.B.; Auffray, E.; Lecoq, P.; Chipaux, R.; Geleoc, M.; Drobychev, G. Yu; Fedorov, A.A.; Korzhik, M.V.; Missevitch, O.V.; Pavlenko, V.B.; Golubev, N.A.; Lednev, A.A.; Peigneux, J.-P.; Singovski, A.V.

    1998-01-01

    The effect of irradiation on lead tungstate PbWO 4 (PWO) scintillator properties has been studied at different irradiation facilities. Lead tungstate crystals, grown with the oxide content in the melt tuned to the stoichiometry of pure sheelite or sheelite-like crystal types and doped with heterovalent, trivalent and pentavalent impurities, have been studied in order to optimize their resistance to irradiation. A combination of a selective cleaning of raw materials, a tuning of the melt from crystallization to crystallization and a destruction or compensation of the point-structure defects has to be used to minimize the short-term instability of PWO parameters under irradiation

  8. Electrical and optical properties of mixed phase tungsten trioxide films grown by laser pyrolysis

    CSIR Research Space (South Africa)

    Govender, M

    2014-02-01

    Full Text Available the tungstate bronzes to tungsten oxide. I-V curves of the films showed n-type semiconducting behaviour, but the mixed phase appeared to cause a similar behaviour of dopants in a semiconductor. The refractive index decreased with increasing wavelength and gave...

  9. Comparative study of biological activity of glutathione, sodium ...

    African Journals Online (AJOL)

    Glutathione (GSH) and sodium tungstate (Na2WO4) are important pharmacological agents. They provide protection to cells against cytotoxic agents and thus reduce their cytotoxicity. It was of interest to study the biological activity of these two pharmacological active agents. Different strains of bacteria were used and the ...

  10. Process and catalysts for the gasification of methanol. [German Patent

    Energy Technology Data Exchange (ETDEWEB)

    Harris, N.; Dennis, A.J.; Shevels, T.F.

    1975-02-13

    The invention concerns catalysts and catalytic processes for the gasification of methanol which is used to manufacture methane from methanol. Mixtures of iron and chromium oxide, phosphate, phosphoric acid, tungstate, tungstic acid, aluminium phosphate, aluminium oxide are suitable as dehydrating catalysts. Gasification takes place together with steam and dehydrogenating catalysts at high temperature. The molar ratios steam: methanol are described.

  11. WO3 nano-ribbons: their phase transformation from tungstite (WO3·H2O) to tungsten oxide (WO3)

    DEFF Research Database (Denmark)

    Ahmadi, Majid; Sahoo, Satyaprakash; Younesi, Reza

    2014-01-01

    Tungsten oxide (WO3) nano-ribbons (NRs) were obtained by annealing tungstite (WO3·H2O) NRs. The latter was synthesized below room temperature using a simple, environmentally benign, and low cost aging treatment of precursors made by adding hydrochloric acid to diluted sodium tungstate solutions (...

  12. Further study on different dopings into PbWO.sub.4./sub. single crystals to increase the scintillation light yield

    Czech Academy of Sciences Publication Activity Database

    Kobayashi, M.; Usuki, Y.; Ishii, M.; Itoh, M.; Nikl, Martin

    2005-01-01

    Roč. 540, - (2005), s. 381-394 ISSN 0168-9002 R&D Projects: GA AV ČR(CZ) KSK1010104 Institutional research plan: CEZ:AV0Z10100521 Keywords : lead tungstate * scintillator * light yield * doping, PET Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.224, year: 2005

  13. Impact of dopant metal ions in the framework of parent zirconia on the n-heptane isomerization activity of the Pt/WO3-ZrO2 catalysts

    Czech Academy of Sciences Publication Activity Database

    Kaucký, Dalibor; Sobalík, Zdeněk; Hidalgo, J. M.; Černý, R.; Bortnovský, O.

    2016-01-01

    Roč. 420, AUG 2016 (2016), s. 107-114 ISSN 0304-5102 R&D Projects: GA MPO FR-TI3/316 Institutional support: RVO:61388955 Keywords : zirconia * tungstated zirconia * dopants Subject RIV: CF - Physical ; Theoretical Chemistry

  14. Fabrication, operation, and applications of efficient dielectric waveguide lasers

    NARCIS (Netherlands)

    Pollnau, Markus; van Dalfsen, Koop; Bernhardi, Edward; Geskus, D.; Worhoff, Kerstin; de Ridder, R.M.; García Blanco, Sonia Maria

    This paper reviews our recent results on rare-earth-ion-doped integrated lasers. We have concentrated our efforts on crystalline potassium double tungstates and amorphous aluminum oxide. In the former material class we have demonstrated channel waveguide lasers based on Yb3+ doping, operating near 1

  15. Large-scale production of PWO scintillation elements for CMS ECAL

    International Nuclear Information System (INIS)

    Annenkov, A.; Auffray, E.; Drobychev, G.; Korzhik, M.; Kostylev, V.; Kovalev, O.; Lecoq, P.; Ligoun, V.; Missevitch, O.; Zouevski, R.

    2005-01-01

    JSC Bogoroditsk Technical Chemical Plant, BTCP, has produced up to date more than 20,000 lead tungstate scintillation elements for the electromagnetic calorimeter of CMS Collaboration. Here we report on the status of the crystal production and results of the quality insurance program, which is performed by the Collaboration in cooperation with BTCP to keep crystal properties within specifications

  16. Corrosion Inhibition in the Secondary Cooling System of ETRR-2, Egypt

    International Nuclear Information System (INIS)

    Aly, A.H.; Gad, M.M.A.; Abdel-Karim, R.; Abdel-Salam, O.F.

    2003-01-01

    The second Egyptian research reactor (ETRR-2) is a light water type of 22 MW thermal power. Proper cooling water treatment is necessary to set the water chemical characteristics within a specified window to avoid or minimize corrosion problems, scale formation, fouling, and microbiological contamination. Selection of a proper and economic corrosion inhibitor is of great importance. This selection depends, among other factors, on the availability as well as cost. The corrosion behaviour of water of ETRR-2 site and its inhibition by different inhibitors was studied in a special test rig designed for this purpose. Sodium salts of polyphosphate, phosphate, molybdate, and tungstate were used to treat and qualify the cooling water. Results showed that the corrosion resistance of the test material depends on both type and concentration of the applied inhibitor. Using 30-ppm tungstate, molybdate, and phosphate (as anodic inhibitors) reduced the corrosion rate, and inhibitor efficiencies of about 97% 86%, and 68% were achieved respectively. Accordingly, sodium tungstate could be ranked as the best anodic inhibitor used followed by molybdate. Sodium phosphate could be ranked as the least efficient one. Adding the same concentration of sodium polyphosphate (as a cathodic inhibitor) yields almost the same inhibition efficiency as tungstate type. However, at higher concentration(40 ppm), an inhibition efficiency of 100% was obtained, Which corresponds to almost zero-corrosion rate

  17. Ionising-radiation detector

    International Nuclear Information System (INIS)

    Hames, G.E.; Reed, J.; Robertson, D.S.

    1982-01-01

    A scintillation crystal/photodiode assembly for the detection of x- and γ-rays is described comprising a single crystal of zinc-tungstate grown from a melt and optically coupled to a photodiode. The crystal is doped with a trace element, for example Ag or Sb, to eliminate the characteristic rose/amber colour of the pure crystal. (U.K.)

  18. Untitled

    Indian Academy of Sciences (India)

    Physico-Chemical Studies on Tungsto-Tartrates and Molybdo-Tartrates 23. Na4CaH2O WO38H2O, by the reaction of sodium tungstate and sodium tattrate. Sarju Prasad and Krishnaiah studied the sedium illsigit- tartaric acid System by viscosity and depression in freezing point measure- ments and indicated the formation ...

  19. Laser profiling of defects in BaWO.sub.4./sub. crystals

    Czech Academy of Sciences Publication Activity Database

    Remeš, Zdeněk; Boháček, Pavel; Nikl, Martin

    2012-01-01

    Roč. 23, č. 8 (2012), 1-4 ISSN 0957-0233 R&D Projects: GA MŠk LH12236; GA MŠk LH12186 Institutional research plan: CEZ:AV0Z10100521 Keywords : barium tungstate * laser scattering * defects * Czochralski method Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.435, year: 2012

  20. Using the computer simulation methods for the PHOS gamma spectrometer in the ALICE design. Pt. 1. Simulation of the base module response on a high-energy gamma quantum

    International Nuclear Information System (INIS)

    Antonenko, V.G.; Blau, D.S.

    2006-01-01

    After all lead tungstate crystals have been fabricated and transferred for assembling of the gamma-spectrometer PHOS in frame of ALICE experiment on the Large Hadron Collider a simulation was performed of the light collection in single scintillation module taking into account realistic properties of entire crystal party [ru

  1. Electron paramagnetic resonance study of copper impurity charge-states in PbWO.sub.4./sub. scintillator

    Czech Academy of Sciences Publication Activity Database

    Hofstaetter, A.; Laguta, V. V.; Meyer, B.K.; Nikl, Martin; Rosa, Jan; Zhu, R.Y.

    2004-01-01

    Roč. 38, - (2004), s. 703-706 ISSN 1350-4487 R&D Projects: GA AV ČR(CZ) KSK1010104 Keywords : electron paramagnetic resonance * tungstates * defects Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.664, year: 2004

  2. A comparative study of the proton transport properties of metal (IV ...

    Indian Academy of Sciences (India)

    Unknown

    study the transport properties of these materials.5,6 The mechanism of diffusion and ionic transport in crystalline ... Cu-Kα radiation with a nickel filter. Chemical ... All the tungstates were hard and white except TiW which is yellow. The chemical.

  3. The electromagnetic calorimeter of the CMS experiment

    International Nuclear Information System (INIS)

    Diemoza, M.

    2003-01-01

    The Electromagnetic Calorimeter of the CMS experiment is made of about 80000 Lead Tungstate scintillating crystals. This project aims to achieve an extreme precision in photons and electrons energy measurement. General motivations, main technical challenges and key points in energy resolution will be discussed in the following

  4. WO.sub.3./sub.-doped zinc borophosphate glasses

    Czech Academy of Sciences Publication Activity Database

    Šubčík, J.; Koudelka, L.; Mošner, P.; Gregora, Ivan; Montagne, L.; Revel, B.

    2009-01-01

    Roč. 50, č. 4 (2009), 243-248 ISSN 1753-3562 R&D Projects: GA AV ČR KAN301370701 Institutional research plan: CEZ:AV0Z10100520 Keywords : tungstate zinc borophosphate glasses * Raman spectroscopy * temperature * NMR Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.553, year: 2009

  5. STUDY ON THE SYNTHESIS AND STRUCTURE OF MACRORETICULAR BEAD PAN/PVC IPN RESINS

    Institute of Scientific and Technical Information of China (English)

    LI Yanfeng; ZHUO Renxi

    1993-01-01

    Macroreticular bead PAN/PVC IPN reans with cyano and chloro groups were synthesized by interpenetrating polymerization of acrylonitrile, or acrylonitrile and divinylbenzene into a macroporous polyvinyl chloride bead. The composition and structure of the bead IPN resins have been investigated by means of FT-IR, NMR, SEM, mercury porosimetry and elemental analysis. During the process of interpenetrating polymerization, the chain propagation obeys Bernoullian statistical law, and no grafting polymerization has been observed. The content of cyano group in the resulting IPN resins can be adjusted by the amount of acrylonitrile added. The morphology of the IPN resins basically resembles that of the polyvinyl chloride bead,whereas the pore structures vary to a certain degree

  6. Ultrasonic degradation of butadiene, styrene and their copolymers.

    Science.gov (United States)

    Sathiskumar, P S; Madras, Giridhar

    2012-05-01

    Ultrasonic degradation of commercially important polymers, styrene-butadiene (SBR) rubber, acrylonitrile-butadiene (NBR) rubber, styrene-acrylonitrile (SAN), polybutadiene rubber and polystyrene were investigated. The molecular weight distributions were measured using gel permeation chromatography (GPC). A model based on continuous distribution kinetics approach was used to study the time evolution of molecular weight distribution for these polymers during degradation. The effect of solvent properties and ultrasound intensity on the degradation of SBR rubber was investigated using different pure solvents and mixed solvents of varying volatility and different ultrasonic intensities. Copyright © 2011 Elsevier B.V. All rights reserved.

  7. Regioselective Synthesis of Some Pyrazole Scaffolds Attached to Benzothiazole and Benzimidazole Moieties

    Directory of Open Access Journals (Sweden)

    Nabila A. Kheder

    2014-01-01

    Full Text Available Condensation of 2-(benzothiazol-2-ylacetonitrile (1 or 2-(1-methyl-1H-benzimidazol-2-ylacetonitrile (2 with thiophene-2-carbaldehyde afforded the corresponding acrylonitrile derivatives 3 or 4, respectively. The 1,3-dipolar cycloaddition reaction of the acrylonitrile 3 or 4 with nitrile-imine 6 gave novel pyrazole derivatives pendant to benzothiazole and benzimidazole. The pyrazoline derivative 7 was converted into the corresponding pyrazole derivative 11 via thermal elimination of hydrogen cyanide upon heating in sodium ethoxide solution. The structures of the synthesized products were confirmed by IR, 1H NMR, and mass spectral techniques.

  8. Dehydroabiethylamine acetate as metal-containing anion precipitant

    International Nuclear Information System (INIS)

    Skrylev, L.D.; Borisov, V.A.

    1979-01-01

    The precipitation is studied of vanadate, tungstate-, molybdate- and chromate-ions by dehydroabiethylamine acetate. The degree of precipitation of metal-bearing anions is a function of the anion and of pH of the treated solutions. There exists a predetermined value of pH for each anion, at which the content of metal-bearing anion in the ultra-filtrate is at a minimum. For vanadate-ions, this pH is 5.0; for tungstate-ions, 3.0; for molybdate-ions, 4.0; for chrommate-ions, 8.0. The heats of solution of methavanadate, paratungstate, paramolybdate and dehydroabiethylamine chromate, calculated in accordance with the Vant-Hoff equation, range between 3.5 and 8.3 kJ/mole; free energy varies between 45.8 and 137.5 kJ/mole; and entropy varies between 110 and 371 J/degree mole

  9. IR spectra and structure of glasses in the BaO-WO3-P2O5 system

    International Nuclear Information System (INIS)

    Miroshnichenko, O.Ya.; Mombelli, V.V.

    1979-01-01

    Studied are IR absorption spectra and determined are the main structural characteristics of tungstophosphate glasses of the BaO-WO 3 -P 2 O 5 system in all the area of glass formation. It is shown that the main structural components of their anion network are phosphate chains consisting of PO 4 tetrahedrons and tungstate chains consisting of WO 4 tetrahedrons and of WO 6 octahedrons. These chains are connected by P-O-W bridges into three-dimentional tungstophosphate network, where the ratio of phosphate and tungstate structural units and their polymerization degree change without limits depending on the glass composition. Analysis of concentration frequency dependence and spectral band intensity permit to clarify the effect of each component on the glass structure in all the area of glass formation of the triple system

  10. First test of an enriched {sup 116}CdWO{sub 4} scintillating bolometer for neutrinoless double-beta-decay searches

    Energy Technology Data Exchange (ETDEWEB)

    Barabash, A.S.; Konovalov, S.I.; Umatov, V.I. [ITEP, National Research Centre ' ' Kurchatov Institute' ' , Moscow (Russian Federation); Danevich, F.A. [MSP, Institute for Nuclear Research, Kyiv (Ukraine); Gimbal-Zofka, Y. [Univ. Paris-Sud, CNRS/IN2P3, Universite Paris-Saclay, CSNSM, Orsay (France); Linnaeus University, Department of Physics and Electrical Engineering, Kalmar (Sweden); Giuliani, A.; Mancuso, M. [Univ. Paris-Sud, CNRS/IN2P3, Universite Paris-Saclay, CSNSM, Orsay (France); DISAT, Universita dell' Insubria, Como (Italy); Marcillac, P. de; Marnieros, S.; Novati, V.; Olivieri, E. [Univ. Paris-Sud, CNRS/IN2P3, Universite Paris-Saclay, CSNSM, Orsay (France); Nones, C.; Zolotarova, A.S. [DSM/IRFU, CEA Saclay, Gif-sur-Yvette Cedex (France); Poda, D.V. [MSP, Institute for Nuclear Research, Kyiv (Ukraine); Univ. Paris-Sud, CNRS/IN2P3, Universite Paris-Saclay, CSNSM, Orsay (France); Shlegel, V.N. [Nikolaev Institute of Inorganic Chemistry, Novosibirsk (Russian Federation); Tretyak, V.I. [MSP, Institute for Nuclear Research, Kyiv (Ukraine); INFN, Sezione di Roma, Rome (Italy)

    2016-09-15

    For the first time, a cadmium tungstate crystal scintillator enriched in {sup 116}Cd has been succesfully tested as a scintillating bolometer. The measurement was performed above ground at a temperature of 18 mK. The crystal mass was 34.5 g and the enrichment level ∝ 82 %. Despite a substantial pile-up effect due to above-ground operation, the detector demonstrated high energy resolution (2-7 keV FWHM in 0.2-2.6 MeV γ energy range and 7.5 keV FWHM at the {sup 116}Cd double-beta decay transition energy of 2813 keV), a powerful particle identification capability and a high level of internal radio-purity. These results prove that cadmium tungstate is a promising detector material for a next-generation neutrinoless double-beta decay bolometric experiment, like that proposed in the CUPID project (CUORE Upgrade with Particle IDentification). (orig.)

  11. Last crystals for the CMS chandelier

    CERN Multimedia

    2008-01-01

    In March, the last crystals for CMS’s electromagnetic calorimeter arrived from Russia and China. Like dedicated jewellers crafting an immense chandelier, the CMS ECAL collaborators are working extremely hard to install all the crystals before the start-up of the LHC. One of the last CMS end-cap crystals, complete with identification bar code. Lead tungstate crystals mounted onto one section of the CMS ECAL end caps. Nearly 10 years after the first production crystal arrived at CERN in September 1998, the very last shipment has arrived. These final crystals will be used to complete the end-caps of the electromagnetic calorimeter (ECAL) at CMS. All in all, there are more than 75,000 crystals in the ECAL. The huge quantity of CMS lead tungstate crystals used in the ECAL corresponds to the highest volume ever produced for a single experiment. The excellent quality of the crystals, both in ter...

  12. Non-destructive local determination of doping additions and main components in single crystals

    International Nuclear Information System (INIS)

    Ehksperiandova, L.P.; Blank, A.B.; Kukhtina, N.N.; Afanasiadi, L.I.

    1994-01-01

    Procedures for local non-destructive determination of elements in optical and scintillation single crystals are developed. They are applied for determination of the main components (in cadmium tungstate) and doping additions (tellurium in zinc selenide, europium in gadolinium silicate). The metrological characteristics of the developed micro-analysis methods are estimated. Segregation of the main components and doping additions in the objects under consideration are investigated. Tellurium is found to be distributed uniformly on the cross-sections of bulk zinc selenide single crystals. The segregation of europium along gadolinium silicate ingots is almost absent. On the cross-section surface of cadmium tungstate single crystals the microregions are found characterized by the prevailing contents of cadmium or tungsten

  13. New doped tungsten cathodes. Applications to power grid tubes

    International Nuclear Information System (INIS)

    Cachard, J. de; Cadoret, K; Martinez, L.; Veillet, D.; Millot, F.

    2001-01-01

    Thermionic emission behavior of tungsten/tungsten carbide modified with rare earth (La, Ce, Y) oxides is examined on account of suitability to deliver important current densities in a thermo-emissive set up and for long lifetime. Work functions of potential cathodes have been determined from Richardson plots for La 2 O 3 doped tungsten and for tungsten covered with variable compositions rare earth tungstates. The role of platinum layers covering the cathode was also examined. Given all cathodes containing mainly lanthanum oxides were good emitters, emphasis was put on service lifetime. Comparisons of lifetime in tungsten doped with rare earth oxides and with rare earth tungstates show that microstructure of the operating cathodes may play the major role in the research of very long lifetime cathodes. Based on these results, tests still running show lifetime compatible with power grid tubes applications. (author)

  14. Measurements and simulations on position dependencies in the response of single PWO crystals and a prototype for the $\\overline{P}ANDA$ EMC

    CERN Document Server

    Bremer, Daniel Andreas

    The PANDA experiment, which will be located at the future Facility for Antiproton and Ion Research, aims at the study of strong interaction within the charm sector via antiproton- proton collisions. An essential component of the PANDA detector to achieve the ambitious physics goals is the Electromagnetic Calorimeter (EMC). Reason for this is particularly its high detection efficiency for photons and electrons over a large dynamic range, since most of the expected physics channels are accompanied by secondary photons. The EMC is based on second generation lead tungstate scintillator crystals and thus features a very compact design and improved performance. To guarantee a homogeneous and precise energy and momentum response, an exact knowledge on the incident particle position is mandatory. In the scope of this work, non-uniformities in the light yield of single lead tungstate crystals with tapered geometry are investigated. This effect was studied with the SLitrani simulation package in comparison to a series ...

  15. Bulletin of Materials Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science; Volume 31; Issue 1. Pressure induced graft-co-polymerization of acrylonitrile onto Saccharum cilliare fibre and ... Author Affiliations. A S Singha1 Anjali Shama1 Vijay Kumar Thakur1. Material Science Laboratory, National Institute of Technology, Hamirpur 177 005, India ...

  16. Research Article Special Issue

    African Journals Online (AJOL)

    pc

    2018-03-07

    Mar 7, 2018 ... The performance of a Malaysian isolated strain, Rhodococcus UKMP-5M in ... Universiti Selangor Culture Collection was isolated from petroleum .... Other factors that may influence the biotransformation of acrylonitrile were also tested and the .... Indian Journal of Fundamental and Applied Life Sciences,.

  17. Extraction of microplastic from biota: recommended acidic digestion destroys common plastic polymers

    DEFF Research Database (Denmark)

    Enders, Kristina; Lenz, Robin; Beer, Sabrina

    2017-01-01

    particles of various polymer types. In the present study we report that a digestion protocol recently recommended by ICES using nitric and perchloric acid has strong detrimental effects on several common plastic polymers, in particular polyamide and polyurethane and to a lesser degree acrylonitrile...

  18. 40 CFR Table 6 to Subpart Jjj of... - Known Organic HAP Emitted From the Production of Thermoplastic Products

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 11 2010-07-01 2010-07-01 true Known Organic HAP Emitted From the... HAP Emitted From the Production of Thermoplastic Products Thermoplastic product/Subcategory Organic HAP/chemical name(CAS No.) Acet-aldehyde (75-07-0) Acrylo-nitrile (107-13-1) 1,3 Buta-diene (106-99-0...

  19. Fabrication of green polymeric membranes

    KAUST Repository

    Kim, Dooli; Nunes, Suzana Pereira

    2017-01-01

    Provided herein are methods of fabricating membranes using polymers with functionalized groups such as sulfone (e.g., PSf and PES), ether (e.g., PES), acrylonitrile (e.g., PAN), fluoride(e.g., pvdf and other fluoropolymers), and imide (e.g., extem) and ionic liquids. Also provided are membranes made by the provided methods.

  20. 21 CFR 173.5 - Acrylate-acrylamide resins.

    Science.gov (United States)

    2010-04-01

    ... produced by the polymerization of acrylamide with partial hydrolysis, or by copolymerization of acrylamide... polyacrylate-acrylamide resin is produced by the polymerization and subsequent hydrolysis of acrylonitrile in a... or cane sugar juice and liquor or corn starch hydrolyzate in an amount not to exceed 5 parts per...