WorldWideScience

Sample records for synthesis characterization reactivity

  1. Synthesis and characterization of reactive dye-cassava mesocarp ...

    The synthesis of triazine based reactive dyes was carried out. The resultant dyes were characterized by thin layers chromatography, molecular weight, infrared and ultra- violet spectroscopy, and used in dyeing cassava mesocarp to produce dye modified cellulosic substrates. The dyed substrates were tested for dye fixation, ...

  2. Synthesis, characterization and reactivity of some lanthanide organometallics

    Marchal, N.

    1991-12-01

    Organo lanthanides with reactive metal-carbon bonds are obtained by direct synthesis of the metal (powder) and a hydrocarbon in ether medium, like with alkali metals. Two types of synthesis are envisaged: formation of covalent bonds by opening cycles, only biphenylene is reactive enough in regard to ytterbium and samarium, these organometallic compounds can also be prepared by the classical way, i.e. reaction of 2.2'-dilithio biphenyl on rare earth halogenides and coupling of 6.6-dimethylfulvene leading to dicyclopentadienyl compounds with Sm and Yb. The reactivity of these complexes is studied by catalysis of ethylene polymerization

  3. Synthesis, characterization and photophysical properties of ESIPT reactive triazine derivatives

    Kuplich, Marcelo D.; Grasel, Fabio S.; Campo, Leandra F.; Rodembusch, Fabiano S.; Stefani, Valter

    2012-01-01

    Four new reactive fluorescent triazine derivatives were obtained from nucleophilic aromatic substitution of cyanuric chloride. The compounds were characterized by infrared spectroscopy (IR), nuclear magnetic resonance ( 13 C and 1 H NMR) and high resolution mass spectrometry (HRMS MALDI). UV-Vis and steady-state fluorescence (in solution and in solid state) spectroscopies were also applied to characterize the photophysical behavior. The dyes are fluorescent by an intramolecular proton transfer mechanism (ESIPT) in the blue-orange region, with a large Stokes shift between 6365-10290 cm-1. The fluorescent cyanuric derivatives could successfully react with cellulose fibers to give new fluorescent cellulosic materials. (author)

  4. Synthesis and Characterization of Organotin Containing Copolymers: Reactivity Ratio Studies

    Mohamed H. El-Newehy

    2010-03-01

    Full Text Available Organotin monomers containing dibutyltin groups – dibutyltin citraconate (DBTC as a new monomer and dibutyltin maleate (DBTM – were synthesized. Free radical copolymerizations of the organotin monomers with styrene (ST and butyl acrylate (BA were performed. The overall conversion was kept low (≤15% wt/wt for all studied samples and the copolymers composition was determined from tin analysis using the Gillman and Rosenberg method. The reactivity ratios were calculated from the copolymer composition using the Fineman-Ross (FR method. The synthesized monomers were characterized by elemental analysis, 1H-, 13C-NMR and FTIR spectroscopy.

  5. Synthesis and characterization of carboxymethyl potato starch and its application in reactive dye printing.

    Zhang, Bing; Gong, Honghong; Lü, Shaoyu; Ni, Boli; Liu, Mingzhu; Gao, Chunmei; Huang, Yinjuan; Han, Fei

    2012-11-01

    Carboxymethyl potato starch (CMPS) was synthesized with a simple dry and multi-step method as a product of the reaction of native potato starch and monochloroacetic acid in the presence of sodium hydroxide. The influence of the molar ratio of sodium hydroxide to anhydroglucose unit, the volume of 95% (v/v) ethanol, the rotation rate of motor driven stirrer and the reaction time for degree of substitution (DS) were evaluated. The product was characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and X-ray diffractometry (XRD). FTIR spectrometry showed new bonds at 1618 and 1424 cm⁻¹ when native starch underwent carboxymethylation. SEM pictures showed that the smooth surface of native starch particles was mostly ruptured. XRD revealed that starch crystallinity was reduced after carboxymethylation. The viscosity of the mixture paste of carboxymethyl starch and sodium alginate (SA) was measured using a rotational viscometer. In addition, the applied effect of mixed paste in reactive dye printing was examined by assessing the fabric stiffness, color yield and sharp edge to the printed image in comparison with SA. And the results indicated that the mixed paste could partially replace SA as thickener in reactive dye printing. The study also showed that the method was low cost and eco-friendly and the product would have an extensive application in reactive dye printing. Copyright © 2012 Elsevier B.V. All rights reserved.

  6. Towards the new heterocycle based molecule: Synthesis, characterization and reactivity study

    Murthy, P. Krishna; Sheena Mary, Y.; Suneetha, V.; Panicker, C. Yohannan; Armaković, Stevan; Armaković, Sanja J.; Giri, L.; Suchetan, P. A.; Van Alsenoy, C.

    2017-06-01

    4-Chloro-2-(3-fluorophenyl)-2,3-dihydro-1H-pyrrolo[3,4-c]pyridin-1-one (CFPDPPO) have been synthesized by hydride transfer from Et3SiH to carbenium ions(reduction reaction), which is formed by reaction between 4-chloro-2-(3-fluorophenyl)-3-hydroxy-2,3-dihydro-1H-pyrrolo[3,4-c]pyridin-1-one with TFA, the single crystals were grown in acetonitrile by slow evaporation technique at room temperature and characterized by single crystal X-ray diffraction, FT-IR, FT-Raman, 1H NMR, 13C NMR and ESI-MS. The experimental vibrational spectra were compared with the calculated spectra and each vibrational wavenumber was assigned on the basis of potential energy distribution (PED). Gauge-including atomic orbital 1H NMR and 13C NMR chemical shifts calculations were carried out and compared with experimental data. The HOMO and LUMO analysis is used to determine the charge transfer within the molecule. The stability of the molecule arising from hyper-conjugative interactions and charge delocalization has been analysed using NBO analysis. First hyperpolarizability is calculated in order to find its role in non-linear optics. Besides molecular electrostatic potential (MEP), global reactivity descriptors, thermodynamic properties, and Mullikan charge analysis of the title compound were computed with the same method in gas phase, theoretically. Further, employing combination of DFT calculations and molecular dynamics (MD) simulations, we have investigated in detail reactive properties of the title molecule. Investigation of local reactive properties encompassed calculations of average local ionization energies (ALIE) and Fukui functions. Stability in water has been investigated by calculations of radial distribution functions (RDF), while sensitivity towards the mechanism of autoxidation has been investigated by calculations of bond dissociation energies (BDE). The docked ligand forms a stable complex with human alpha9 nicotinic acetylcholine receptor antagonist and can be a lead

  7. Synthesis, characterization, and reactivity of ruthenium hydride complexes of N-centered triphosphine ligands.

    Phanopoulos, Andreas; Brown, Neil J; White, Andrew J P; Long, Nicholas J; Miller, Philip W

    2014-04-07

    The reactivity of the novel tridentate phosphine ligand N(CH2PCyp2)3 (N-triphos(Cyp), 2; Cyp = cyclopentyl) with various ruthenium complexes was investigated and compared that of to the less sterically bulky and less electron donating phenyl derivative N(CH2PPh2)3 (N-triphos(Ph), 1). One of these complexes was subsequently investigated for reactivity toward levulinic acid, a potentially important biorenewable feedstock. Reaction of ligands 1 and 2 with the precursors [Ru(COD)(methylallyl)2] (COD = 1,5-cycloocatadiene) and [RuH2(PPh3)4] gave the tridentate coordination complexes [Ru(tmm){N(CH2PR2)3-κ(3)P}] (R = Ph (3), Cyp (4); tmm = trimethylenemethane) and [RuH2(PPh3){N(CH2PR2)3-κ(3)P}] (R = Ph (5), Cyp (6)), respectively. Ligands 1 and 2 displayed different reactivities with [Ru3(CO)12]. Ligand 1 gave the tridentate dicarbonyl complex [Ru(CO)2{N(CH2PPh2)3-κ(3)P}] (7), while 2 gave the bidentate, tricarbonyl [Ru(CO)3{N(CH2PCyp2)3-κ(2)P}] (8). This was attributed to the greater electron-donating characteristics of 2, requiring further stabilization on coordination to the electron-rich Ru(0) center by more CO ligands. Complex 7 was activated via oxidation using AgOTf and O2, giving the Ru(II) complexes [Ru(CO)2(OTf){N(CH2PPh2)3-κ(3)P}](OTf) (9) and [Ru(CO3)(CO){N(CH2PPh2)3-κ(3)P}] (11), respectively. Hydrogenation of these complexes under hydrogen pressures of 3-15 bar gave the monohydride and dihydride complexes [RuH(CO)2{N(CH2PPh2)3-κ(3)P}] (10) and [RuH2(CO){N(CH2PPh2)3-κ(3)P}] (12), respectively. Complex 12 was found to be unreactive toward levulinic acid (LA) unless activated by reaction with NH4PF6 in acetonitrile, forming [RuH(CO)(MeCN){N(CH2PPh2)3-κ(3)P}](PF6) (13), which reacted cleanly with LA to form [Ru(CO){N(CH2PPh2)3-κ(3)P}{CH3CO(CH2)2CO2H-κ(2)O}](PF6) (14). Complexes 3, 5, 7, 8, 11, and 12 were characterized by single-crystal X-ray crystallography.

  8. The Synthesis, Characterization and Reactivity of a Series of Ruthenium N-triphos Ph Complexes.

    Phanopoulos, Andreas; Long, Nicholas; Miller, Philip

    2015-04-10

    Herein we report the synthesis of a tridentate phosphine ligand N(CH2PPh2)3 (N-triphos(Ph)) (1) via a phosphorus based Mannich reaction of the hydroxylmethylene phosphine precursor with ammonia in methanol under a nitrogen atmosphere. The N-triphos(Ph) ligand precipitates from the solution after approximately 1 hr of reflux and can be isolated analytically pure via simple cannula filtration procedure under nitrogen. Reaction of the N-triphos(Ph) ligand with [Ru3(CO)12] under reflux affords a deep red solution that show evolution of CO gas on ligand complexation. Orange crystals of the complex [Ru(CO)2{N(CH2PPh2)3}-κ(3)P] (2) were isolated on cooling to RT. The (31)P{(1)H} NMR spectrum showed a characteristic single peak at lower frequency compared to the free ligand. Reaction of a toluene solution of complex 2 with oxygen resulted in the instantaneous precipitation of the carbonate complex [Ru(CO3)(CO){N(CH2PPh2)3}-κ(3)P] (3) as an air stable orange solid. Subsequent hydrogenation of 3 under 15 bar of hydrogen in a high-pressure reactor gave the dihydride complex [RuH2(CO){N(CH2PPh2)3}-κ(3)P] (4), which was fully characterized by X-ray crystallography and NMR spectroscopy. Complexes 3 and 4 are potentially useful catalyst precursors for a range of hydrogenation reactions, including biomass-derived products such as levulinic acid (LA). Complex 4 was found to cleanly react with LA in the presence of the proton source additive NH4PF6 to give [Ru(CO){N(CH2PPh2)3}-κ(3)P{CH3CO(CH2)2CO2H}-κ(2)O](PF6) (6).

  9. Reactive Coevaporation Synthesis and Characterization of SrTiO3 Thin Films

    Yamaguchi, Hiromu; Matsubara, Shogo; Miyasaka, Yoichi

    1991-09-01

    SrTiO3 thin films were prepared by the reactive coevaporation method, where the Ti and Sr metals were evaporated in oxygen ambient with an E-gun and K-cell, respectively. A uniform depth profile in composition was achieved by altering the Ti evaporation rate according to the Sr evaporation rate change. A typical dielectric constant of 170 was measured on films of 75 nm in thickness. The in-situ annealing in oxygen plasma reduced the leakage current.

  10. Studies on the Synthesis,Characterization and Properties of the Reactive Thermotropic Liquid Crystalline Polymer

    2007-01-01

    1 Introduction Four species of reactive thermotropic liquid crystalline polymer (LCMC) with different relative molecular weight were synthesized in this work (see scheme 1, n=2, 6, 10, ∞.n means number of repeat structure unit). Their structure, morphology and properties were investigated systemically by differential scanning calorimetry (DSC), Thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), Wide-angle X-ray diffraction (WAXD), polarizing opticalmicroscopy (POM) and ubb...

  11. Synthesis and Characterization of Core-Shell Acrylate Based Latex and Study of Its Reactive Blends

    Ying Nie

    2008-03-01

    Full Text Available Techniques in resin blending are simple and efficient method for improving the properties of polymers, and have been used widely in polymer modification field. However, polymer latex blends such as the combination of latexes, especially the latexes with water-soluble polymers, were rarely reported. Here, we report a core-shell composite latex synthesized using methyl methacrylate (MMA, butyl acrylate (BA, 2-ethylhexyl acrylate (EHA and glycidyl methacrylate (GMA as monomers and ammonium persulfate and sodium bisulfite redox system as the initiator. Two stages seeded semi-continuous emulsion polymerization were employed for constructing a core-shell structure with P(MMA-co-BA component as the core and P(EHA-co-GMA component as the shell. Results of Transmission Electron Microscopy (TEM and Dynamics Light Scattering (DLS tests confirmed that the particles obtained are indeed possessing a desired core-shell structural character. Stable reactive latex blends were prepared by adding the latex with waterborne melamine-formaldehyde resin (MF or urea-formaldehyde resin (UF. It was found that the glass transition temperature, the mechanical strength and the hygroscopic property of films cast from the latex blends present marked enhancements under higher thermal treatment temperature. It was revealed that the physical properties of chemically reactive latexes with core-shell structure could be altered via the change of crosslinking density both from the addition of crosslinkers and the thermal treatment.

  12. Copolymerization of 4-Acetylphenyl Methacrylate with Ethyl Methacrylate: Synthesis, Characterization, Monomer Reactivity Ratios, and Thermal Properties

    Gamze Barim

    2014-01-01

    Full Text Available Methacrylates have high glass transition temperature (Tg values and high thermal stability. A new methacrylate copolymer, poly(4-acetylphenyl methacrylate-co-ethyl methacrylate (APMA-co-EMA, was synthesized. The thermal behaviors of copolymers were investigated by differential scanning calorimetry and thermogravimetric analysis. They behaved as new single polymers with single Tg’s and the thermal stability of the copolymers increased with increasing 4-acetylphenyl methacrylate (APMA fraction, leading to the manufacture of copolymers with desired Tg values. Structure and composition of copolymers for a wide range of monomer feed ratios were determined by Fourier transform infrared (FT-IR and 1H-nuclear magnetic resonance (1H-NMR spectroscopic techniques. Copolymerization reactions were continued up to 40% conversions. The monomer reactivity ratios for copolymer system were determined by the Kelen-Tüdös (ra(APMA=0.81; rb(EMA=0.61 and extended Kelen-Tüdös (ra=0.77; rb=0.54 methods and a nonlinear least squares (ra=0.74; rb=0.49 method.

  13. Synthesis, characterization and reactivity of nitrite and nitrosyl derivates of phosphane complexes of tetraamminrethenium (II)

    Souza Santos, L. de.

    1988-01-01

    The substitution reaction: trans-[Ru(NH 3 ) 4 P(III) (H 2 O)] 2+ + NO - 2 K 1 K -1 trans-[Ru(NH 3 ) 4 P(III) (NO 2 ) + + H 2 O. The reaction product has been isolated as trans-[Ru(NH 3 ) 4 P(III) (NO 2 )] (PF 6 ) and characterized by using electronic and infrared spectroscopies and cyclic voltammetry, microanalysis and conductometry techniques. This nitrite complex can be converted into the nitrosyl complex in solution by adding H + , according to: trans-[Ru(NH 3 ) 4 P(III) (NO 2 )] + + 2H + →sup (K)1 trans-[Ru(NH 3 ) 4 P(III) (NO)] 3+ + H 2 O which can be converted back to the nitrite derivative by adding alkali: trans-[Ru(NH 3 ) 4 P(III) (NO)] 3+ + 2 OH - →sup (K)-1 trans-[Ru(NH 3 ) 4 P(III) (NO 2 )] + + H 2 O. The nitrosyl complexes have been synthesized by reaction of NO with trans-[Ru(NH 3 ) 4 P(III) ( 2 O)] 2+ or by reacting the nitrite derivative in acidic solutions, and characterized by eletronic and infrared spetroscopies, cyclic voltametry, microanalysis, eletron paramagnetic resonance (E.P.R.) and nuclear magnetic resonance (N.M.R.) techniques. E.P.R. and N.M.R. data suggest that these complexes are diamagnetic and better formulated as Ru(II)-NO + . (author) [pt

  14. Synthesis, characterization, and reactivity of furan- and thiophene-functionalized bis(n-heterocyclic carbene) complexes of iron(II)

    Rieb, Julia; Raba, Andreas; Haslinger, Stefan; Kaspar, Manuel; Pö thig, Alexander; Cokoja, Mirza; Basset, Jean-Marie; Kü hn, Fritz

    2014-01-01

    The synthesis of iron(II) complexes bearing new heteroatom-functionalized methylene-bridged bis(N-heterocyclic carbene) ligands is reported. All complexes are characterized by single-crystal X-ray diffraction (SC-XRD), nuclear magnetic resonance

  15. Copolymers of N-cyclohexylacrylamide and n-butyl acrylate: synthesis, characterization, monomer reactivity ratios and mean sequence length

    2007-06-01

    Full Text Available Copolymerization of N-cyclohexylacrylamide (NCHA and n-butyl acrylate (BA was carried out in dimethylformamide at 55±1°C using azobisisobutyronitrile as a free radical initiator. The copolymers were characterized by 1H-NMR spectroscopy and the copolymer compositions were determined by 1H-NMR analysis. The reactivity ratios of the monomers were determined by both linear and non-linear methods. The reactivity ratios of monomers determined using linear methods like Fineman-Ross (r1 = 0.37 and r2 = 1.77 , Kelen-Tudos (r1 = 0.38 and r2 = 1.77, ext. Kelen-Tudos (r1 = 0.37 and r2 = 1.75 Yezrieler-Brokhina-Roskin (r1 = 0.37 and r2 = 1.77 and non-linear methods like Tidwell-Mortimer (r1 = 0.37 and r2 = 1.76, ProCop (r1 = 0.36 and r2 = 1.82. The Q and e values for NCHA are 0.67 and 0.68 respectively. Mean sequence lengths of copolymers are estimated from r1 and r2 values. It shows that the BA units increases in a linear fashion in the polymer chain as the concentration of BA increases in the monomer feed.

  16. Synthesis, characterization, and reactivity of furan- and thiophene-functionalized bis(n-heterocyclic carbene) complexes of iron(II)

    Rieb, Julia

    2014-09-15

    The synthesis of iron(II) complexes bearing new heteroatom-functionalized methylene-bridged bis(N-heterocyclic carbene) ligands is reported. All complexes are characterized by single-crystal X-ray diffraction (SC-XRD), nuclear magnetic resonance (NMR) spectroscopy, and elemental analysis. Tetrakis(acetonitrile)-cis-[bis(o-imidazol-2-ylidenefuran)methane]iron(II) hexafluorophosphate (2a) and tetrakis(acetonitrile)-cis-[bis(o-imidazol-2-ylidenethiophene)methane]iron(II) hexafluorophosphate (2b) were obtained by aminolysis of [Fe{N(SiMe3)2}2(THF)] with furan- and thiophene-functionalized bis(imidazolium) salts 1a and 1b in acetonitrile. The SC-XRD structures of 2a and 2b show coordination of the bis(carbene) ligand in a bidentate fashion instead of a possible tetradentate coordination. The four other coordination sites of these distorted octahedral complexes are occupied by acetonitrile ligands. Crystallization of 2a in an acetone solution by the slow diffusion of Et2O led to the formation of cisdiacetonitriledi[ bis(o-imidazol-2-ylidenefuran)methane]iron(II) hexafluorophosphate (3a) with two bis(carbene) ligands coordinated in a bidentate manner and two cis-positioned acetonitrile molecules. Compounds 2a and 2b are the first reported iron(II) carbene complexes with four coordination sites occupied by solvent molecules, and it was demonstrated that those solvent ligands can undergo ligand-exchange reactions.

  17. Orifice microreactor for the production of an organic peroxide – non-reactive and reactive characterization

    Illg, T.; Hessel, V.; Löb, P.; Schouten, J.C.

    2012-01-01

    In this article, the transfer of a two-step, biphasic, and exothermic peroxide synthesis into a microreactor assisted process is discussed as well as the non-reactive and reactive characterization of the developed orifice microreactor. Residence time distribution measurements showed nearly ideal

  18. Synthesis and characterization of in situ TiC–TiB2 composite coatings by reactive plasma spraying on a magnesium alloy

    Zou Binglin; Tao Shunyan; Huang Wenzhi; Khan, Zuhair S.; Fan Xizhi; Gu Lijian; Wang Ying; Xu Jiaying; Cai Xiaolong; Ma Hongmei; Cao Xueqiang

    2013-01-01

    Highlights: ► TiC–TiB 2 composites coatings were produced on Mg alloy by reactive plasma spraying. ► Phase composition, microstructure and wear resistance of the coatings were studied. ► The resultant product in the coatings was composed of TiC and TiB 2 . ► The produced coatings displayed porous and dense microstructures. ► The synthesized coatings exhibited good wear resistance for Mg alloy substrate. - Abstract: TiC–TiB 2 composite coatings were successfully synthesized using the technique of reactive plasma spraying (RPS) on a magnesium alloy. Phase composition, microstructure and wear resistance of the coatings were characterized by using X-ray diffraction, scanning electron microscopy and pin-on-disk wear test, respectively. The results showed that the resultant product in the RPS coatings was composed of TiC and TiB 2 . Depending on the ignition of self-propagating high-temperature synthesis reaction in the agglomerate particles, the RPS coatings displayed porous and dense microstructures. The porosity of the RPS coatings, to some extent, decreased when the feed powders were plasma sprayed with Ni powders. The RPS coatings provided good wear resistance for the substrate under various loads. For high loads (e.g., ≥15 N), the wear resistance could be significantly improved by the proper addition of Ni into the RPS coatings.

  19. SYNTHESIS, CHARACTERIZATION AND PHOTOCATALYTIC ...

    ISSN 1011-3924. © 2018 Chemical Society of Ethiopia and The Authors. Printed in Ethiopia ... SYNTHESIS, CHARACTERIZATION AND PHOTOCATALYTIC ACTIVITY OF .... cm−1 to determine the surface functional groups. 10 mg of sample ...

  20. Synthesis and characterization of porous crystalline SiC thin films prepared by radio frequency reactive magnetron sputtering technique

    Qamar, Afzaal, E-mail: afzaalqamar@gmail.com [Department of Physics and Applied Mathematics, PIEAS, Nilore, Islamabad, Punjab 42600 (Pakistan); Mahmood, Arshad [National Institute of Laser and Optronics, Nilore, Islamabad (Pakistan); Sarwar, Tuba; Ahmed, Nadeem [Department of Physics and Applied Mathematics, PIEAS, Nilore, Islamabad, Punjab 42600 (Pakistan)

    2011-05-15

    Hexagonal SiC thin films have been deposited using radio frequency reactive magnetron sputtering technique by varying the substrate temperature and other deposition conditions. Prior to deposition surface modification of the substrate Si(1 0 0) played an important role in deposition of the hexagonal SiC structure. The effect of substrate temperature during deposition on structure, composition and surface morphology of the SiC films has been analyzed using atomic force microscopy, Fourier transform infrared spectroscopy and spectroscopic ellipsometry. X-ray diffraction in conventional {theta}-2{theta} mode and omega scan mode revealed that the deposited films were crystalline having 8H-SiC structure and crystallinity improved with increase of deposition temperature. The bonding order and Si-C composition within the films showed improvement with the increase of deposition temperature. The surface of thin films grew in the shape of globes and columns depending upon deposition temperature. The optical properties also showed improvement with increase of deposition temperature and the results obtained by ellipsometry reinforced the results of other techniques.

  1. Synthesis, characterization, antimicrobial and antitumor reactivity of new palladium(II) complexes with methionine and tryptophane coumarine derivatives

    Stojković, Danijela Lj; Jevtić, Verica V.; Vuković, Nenad; Vukić, Milena; Čanović, Petar; Zarić, Milan M.; Mišić, Milena M.; Radovanović, Dragče M.; Baskić, Dejan; Trifunović, Srećko R.

    2018-04-01

    In reaction of 3-acetyl-4-hydroxy coumarine with methionine methyl ester hydrochloride and tryptophane methyl ester hydrochloride the corresponding enamine ligands were obtained. Palladium (II) complexes were prepared in reaction of potassium-tetrachloridopalladate (II) and corresponding enamine. All compounds were characterized by microanalysis, infrared, 1H and 13C NMR spectroscopy. In vitro antitumor activity of the mentioned ligands and corresponding palladium (II) complexes, as well as me-Gly and me-Val ligands and [Pd (me-Gly)]Cl and [Pd (me-Val)2] complexes was determined by MTT assay against two leukemia cell lines (JVM-13 and MOLT-4) and against primary leukemic cells isolated from chronic lymphocytic leukemia (CLL) patients. Antimicrobial activity of the tested compound was evaluated by determining the minimum inhibitory concentration (MIC) and minimum microbicidal concentration (MMC) against three reference bacterial strains: E. faecalis, P. aeruginosa, S. aureus and one clinical isolate of yeast: Candida spp.

  2. Synthesis and reactivity of dimethyl gold complexes supported on MgO: characterization by infrared and X-ray absorption spectroscopies

    Guzman, J.; Anderson, B.G.; Vinod, C.P.; Ramesh, K.; Niemantsverdriet, J.W.; Gates, B.C.

    2005-01-01

    Di-Me gold complexes bonded to partially dehydroxylated MgO powder calcined at 673 K were synthesized by adsorption of Au(CH3)2(acac) (acac is C5H7O2) from n-pentane soln. The synthesis and subsequent decompn. of the complexes by treatment in He or H2 were characterized with diffuse reflectance

  3. Synthesis and characterization of triangulene

    Pavliček, Niko; Mistry, Anish; Majzik, Zsolt; Moll, Nikolaj; Meyer, Gerhard; Fox, David J.; Gross, Leo

    2017-05-01

    Triangulene, the smallest triplet-ground-state polybenzenoid (also known as Clar's hydrocarbon), has been an enigmatic molecule ever since its existence was first hypothesized. Despite containing an even number of carbons (22, in six fused benzene rings), it is not possible to draw Kekulé-style resonant structures for the whole molecule: any attempt results in two unpaired valence electrons. Synthesis and characterization of unsubstituted triangulene has not been achieved because of its extreme reactivity, although the addition of substituents has allowed the stabilization and synthesis of the triangulene core and verification of the triplet ground state via electron paramagnetic resonance measurements. Here we show the on-surface generation of unsubstituted triangulene that consists of six fused benzene rings. The tip of a combined scanning tunnelling and atomic force microscope (STM/AFM) was used to dehydrogenate precursor molecules. STM measurements in combination with density functional theory (DFT) calculations confirmed that triangulene keeps its free-molecule properties on the surface, whereas AFM measurements resolved its planar, threefold symmetric molecular structure. The unique topology of such non-Kekulé hydrocarbons results in open-shell π-conjugated graphene fragments that give rise to high-spin ground states, potentially useful in organic spintronic devices. Our generation method renders manifold experiments possible to investigate triangulene and related open-shell fragments at the single-molecule level.

  4. Synthesis, characterization, thermal

    Selma Bal

    2017-09-01

    Full Text Available This work explains the synthesis of a new azo-Schiff base compound, derived from condensation between N-ethylcarbazole-3-carbaldehyde and 1,3-diaminopropane, followed by azo coupling reaction with the diazonium salt of 2-amino-4-methyl phenol. The newly synthesized azo-Schiff base was further reacted with the acetate salts of Copper, Cobalt and Nickel to give three coordination compounds. All synthesized compounds have been characterized through spectral analysis. The coordination compounds have been examined for their thermal and catalytic features. Good and moderate yields were obtained for the oxidation of styrene and cyclohexene. Thermal features of the ligand and its complexes have been explained and the results obtained have supported the proposed structures.

  5. Polymer/organosilica nanocomposites based on polyimide with benzimidazole linkages and reactive organoclay containing isoleucine amino acid: Synthesis, characterization and morphology properties

    Mallakpour, Shadpour; Dinari, Mohammad

    2012-01-01

    Highlights: ► A reactive organoclay was formed using L-isoleucine amino acid as a swelling agent. ► Polyimide was synthesized from benzimidazole diamine and pyromellitic dianhydride. ► Imide and benzimidazole groups assured the thermal stability of the nanocomposites. ► Nanocomposite films were prepared by an in situ polymerization reaction. ► The TEM micrographs of nanocomposites revealed well-exfoliated structures. -- Abstract: Polyimide–silica nanocomposites are attractive hybrid architectures that possess excellent mechanical, thermal and chemical properties. But, the dispersion of inorganic domains in the polymer matrix and the compatibility between the organic and inorganic phases are critical factors in these hybrid systems. In this investigation, a reactive organoclay was prepared via ion exchange reaction between protonated form of difunctional L-isoleucine amino acid as a swelling agent and Cloisite Na + montmorillonite. Amine functional groups of this swelling agent formed an ionic bond with the negatively charged silicates, whereas the remaining acid functional groups were available for further interaction with polymer chains. Then organo-soluble polyimide (PI) have been successfully synthesized from the reaction of 2-(3,5-diaminophenyl)-benzimidazole and pyromellitic dianhydride in N,N-dimethylacetamide. Finally, PI/organoclay nanocomposite films enclosing 1%, 3%, 5%, 7% and 10% of synthesized organoclay were successfully prepared by an in situ polymerization reaction through thermal imidization. The synthesized hybrid materials were subsequently characterized by Fourier transform infrared spectroscopy, X-ray diffraction, electron microscopy, and thermogravimetric analysis techniques. The PI/organoclay nanocomposite films have good optical transparencies and the mechanical properties were substantially improved by the incorporation of the reactive organoclay.

  6. Preparation of high temperature superconductor ceramics using cuban reactives. Optimization of the synthesis method

    Leyva Fabelo, A.; Cruz, C.; Aragon, B.; Suarez, J.C.; Mora, M.

    1991-01-01

    Results of the crystallographic characterization of a group of Cuban Products, which are evaluated to be employed in HTSC fabrication are presented in this paper. The first results on the synthesis of HTSC (RBa 2 Cu 3 0 7δ , R= Y, La, Nd) using Cuban reactives, are presented. The so called 'solid state reaction method of synthesis' was optimized, obtaining a critical temperature of more than 93 k

  7. SYNTHESIS, CHARACTERIZATION AND ANTIBACTERIAL ...

    Preferred Customer

    In the present study, synthesis, and biological evaluation of some novel ... Then slowly cooled and resultant mixture was basified with aqueous sodium hydroxide ... mol), anhydrous potassium carbonate (5.52 g, 0.04 mol) in acetone (25 mL), ...

  8. Synthesis, characterization and properties

    Unknown

    work, we report herein the synthesis, structural cha- racterization and properties of a chiral Mn(IV) mononuclear ... atmosphere with a platinum disc working electrode, a platinum wire auxiliary electrode and a Ag/AgCl ... SMART APEX CCD area detector system [λ(Mo-. Kα) = 0⋅71073 Å], graphite monochromator, 2400.

  9. Hydrothermal synthesis, characterization and luminescent ...

    Home; Journals; Bulletin of Materials Science; Volume 39; Issue 4. Hydrothermal synthesis, characterization and luminescent properties of lanthanide-doped NaLaF 4 nanoparticles. JIGMET LADOL HEENA KHAJURIA SONIKA KHAJURIA ... Keywords. Citric acid; X-ray diffraction; down-conversion emission; energy transfer.

  10. Two Step Synthesis of a Non-symmetric Acetylcholinesterase Reactivator

    Vit Koleckar

    2007-08-01

    Full Text Available The newly developed and very promising acetylcholinesterase reactivator (E-1- (2-hydroxyiminomethylpyridinium-4-(4-hydroxyiminomethylpyridinium-but-2-ene dibromide was prepared using two different pathways via a two-step synthesis involving the appropriate (E-1-(4-bromobut-2-enyl-2- or 4-hydroxyiminomethyl-pyridinium bromides. Afterwards, purities and yields of the desired product prepared by both routes were compared. Finally, its potency to reactivate several nerve agent-inhibited acetylcholinesterases was tested.

  11. SYNTHESIS, SPECTRAL CHARACTERIZATIONS AND ...

    Preferred Customer

    A series of 4-chloro-2-[(arylmethylidene)amino]phenols (1–11) including methoxy group ... The structures of the Schiff bases were characterized by FT-IR, .... The characteristic ν(C-H) modes of ring residues are observed at near 3050 cm–1.

  12. Design and synthesis of reactive separation systems

    Doherty, M.F.

    1992-01-01

    During the last decade there has been a rapid upturn in interest in reactive distillation. The chemical process industry recognizes the favorable economics of carrying out reaction simultaneously with distillation for certain classes of reacting systems, and many new processes have been built based on this technology. Interest is also increasing by academics and software vendors. Systematic design methods for reactive distillation systems have only recently begun to emerge. In this report we survey the available design techniques and point out the contributions made by our group at the University of Massachusetts.

  13. Mass spectrometry in the characterization of reactive metal alkoxides.

    Peruzzo, Valentina; Chiurato, Matteo Andrea; Favaro, Monica; Tomasin, Patrizia

    2018-01-01

    Metal alkoxides are metal-organic compounds characterized by the presence of MOC bonds (M = metal). Their chemistry seems to be, in principle, relatively simple but the number of possible reactant species arising as a consequence of their behavior is very remarkable. The physico-chemical properties of metal alkoxides are determined by many different parameters, the most important ones being the electronegativity of the metal, the ramification of the ligand, and the acidity of the corresponding alcohol. Their reactivity makes them suitable and versatile candidates for many applications, including homogeneous catalysis, synthesis of new ceramic materials through the sol-gel process and, recently, also for Cultural Heritage. Metal alkoxides are characterized by a strong tendency to give clusters and/or oligomers through oxo-bridges. Mass spectrometry has been successfully employed for the characterization of metal alkoxides in the gas-phase. Electron ionization (EI) allowed the assessment of the molecular weight and of the most relevant decomposition pathways giving information on the relative bond strength of differently substituted molecules. On the other hand, information on the reactivity in solution of these molecules have been obtained by electrospray ionization (ESI)-matrix assisted laser desorption ionization (MALDI) experiments performed on their reaction products. These data were relevant to investigate the sol-gel process. In this review, these aspects are described and the results obtained are critically evaluated. © 2016 Wiley Periodicals, Inc. Mass Spec Rev. © 2016 Wiley Periodicals, Inc.

  14. SYNTHESIS, REACTIVITY AND BIOLOGICAL ACTIVITY OF QUINOXALIN-2-ONE DERIVATIVES

    El Mokhtar Essassi; R. Bouhfid; Y. Kandri Rodi; S. Ferfra; H. Benzeid; Y. Ramli

    2010-01-01

    Quinoxalines have a great interest in various fields and particularly in chemistry, biology and pharmacology. It enabled the researchers to develop many methods for their preparations and to seek new fields of application. In this review, we’ll expose different methods of synthesis of the quinoxalin-2-one, its reactivity and finally we’ll discuss the various biological activities of its derivatives.

  15. Entrainer-based reactive distillation versus conventional reactive distillation for the synthesis of fatty acid esters

    Jong, de M.C.; Dimian, A.C.; Haan, de A.B.

    2008-01-01

    In this paper different reactive distillation configurations for the synthesis of isopropyl myristate were compared with the use of process models made in Aspen Plus. It can be concluded that the configurations in which an entrainer is added are more capable to reach the required conversion of

  16. Chemical synthesis, characterization studies and reactivity of a catalytic material based on ZrO2-H3PW12O40

    Hernandez Enriquez, Juan Manuel; Garcia Alamilla, Ricardo; Paramo Garcia, Ulises; Rodrigo, Rebeca Silva; Garcia Serrano, Luz Arcelia

    2013-01-01

    In this work, the preparation and characterization of materials such as zirconium oxide (ZrO 2 ) and phosphotungstic acid promoted zirconium oxide (ZrO 2 -H 3 PW 12 O 40 ) is presented. Physico-chemical characterization results showed that addition of H 3 PW 12 O 40 acted as both a textural and chemical promoter of zirconium oxide. The incorporation of phosphotungstic acid into the ZrO 2 matrix delayed the sintering of the material and stabilized ZrO 2 in the tetragonal phase. ZrO 2 acidity was also enhanced, developing strong acid sites on its surface. The Pt/ZrO 2 -H 3 PW 12 O 40 catalyst was active for n-pentane isomerization at 250 deg C, exhibiting high selectivity to iso-pentane (95%). This result is probably due to its suitable acidity (author)

  17. Reactivity of organic compounds in catalytic synthesis

    Minachev, Kh M; Bragin, O V

    1978-01-01

    A comprehensive review of 1976 Soviet research on catalysis delivered to the 1977 annual session of the USSR Academy of Science Council on Catalysis (Baku 6/16-20/77) covers hydrocarbon reactions, including hydrogenation and hydrogenolysis, dehydrogenation, olefin dimerization and disproportionation, and cyclization and dehydrocyclization (e.g., piperylene cyclization and ethylene cyclotrimerization); catalytic and physicochemical properties of zeolites, including cracking, dehydrogenation, and hydroisomerization catalytic syntheses and conversion of heterocyclic and functional hydrocarbon derivatives, including partial and total oxidation (e.g., of o-xylene to phthalic anhydride); syntheses of thiophenes from alkanes and hydrogen sulfide over certain dehydrogenation catalysts; catalytic syntheses involving carbon oxides ( e.g., the development of a new heterogeneous catalyst for hydroformylation of olefins), and of Co-MgO zeolitic catalysts for synthesis of aliphatic hydrocarbons from carbon dioxide and hydrogen, and fabrication of high-viscosity lubricating oils over bifunctional aluminosilicate catalysts.

  18. Synthesis and structural characterization of lithium

    synthesis and characterization of two new iminophos- phonamine ligands ... structures. 2.3 General synthetic method for ligands (1 and 2) ... 2.3b General method for the Synthesis of ligands ...... studies are currently underway in our laboratory.

  19. Egg white hybrid nanoflower (EW-hNF) with biomimetic polyphenol oxidase reactivity: Synthesis, characterization and potential use in decolorization of synthetic dyes.

    Altinkaynak, Cevahir; Kocazorbaz, Ebru; Özdemir, Nalan; Zihnioglu, Figen

    2018-04-01

    In this study, for the first time, we described organic-inorganic hybrid nanoflowers using crude egg white as the organic component and copper (II) ions as the inorganic component under the mild conditions. The synthesized egg white-inorganic hybrid nanoflowers (EW-hNFs) were characterized using SEM, EDX, XRD and FTIR analysis. The biomimetic Polyphenol/Peroxidase like activities of synthesized egg white-inorganic hybrid nanoflowers (EW-hNFs) were determined by using various phenolics with or without H 2 O 2 . Optimum pH and temperature, kinetic parameters, reusability, pH and thermal stability of EW-hNFs were also studied. The most noteworthy aspect of our study is that synthesized EW-hNFs which consist of only egg white proteins, showed polyphenol oxidase activity. Furthermore, potential use of the EW-hNFs in the discoloration of the some synthetic dyes was also evaluated. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Synthesis and reactivity of triscyclopentadienyl uranium (III) and (IV) complexes

    Berthet, J.C.

    1992-01-01

    The reactions of (RC 5 H 4 ) 3 U with R=trimethylsilylcyclopentadienyl or tertiobutylcyclopentadienyl are studied for the synthesis of new uranium organometallic compounds. Reactions with sodium hydride are first described uranium (III) anionic hydrides obtained are oxidized for synthesis of stable uranium (IV) organometallic hydrides. Stability of these compounds is discussed. Reactivity of these uranium (III) and (IV) hydrides are studied. Formation of new binuclear compounds with strong U-O and U-N bonds is examined and crystal structure are presented. Monocyclooctatetraenylic uranium complexes are also investigated

  1. Styrene-spaced copolymers including anthraquinone and β-O-4 lignin model units: synthesis, characterization and reactivity under alkaline pulping conditions.

    Megiatto, Jackson D; Cazeils, Emmanuel; Ham-Pichavant, Frédérique; Grelier, Stéphane; Gardrat, Christian; Castellan, Alain

    2012-05-14

    A series of random copoly(styrene)s has been synthesized via radical polymerization of functionalized anthraquinone (AQ) and β-O-4 lignin model monomers. The copolymers were designed to have a different number of styrene spacer groups between the AQ and β-O-4 lignin side chains aiming at investigating the distance effects on AQ/β-O-4 electron transfer mechanisms. A detailed molecular characterization, including techniques such as size exclusion chromatography, MALDI-TOF mass spectrometry, and (1)H, (13)C, (31)P NMR and UV-vis spectroscopies, afforded quantitative information about the composition of the copolymers as well as the average distribution of the AQ and β-O-4 groups in the macromolecular structures. TGA and DSC thermal analysis have indicated that the copolymers were thermally stable under regular pulping conditions, revealing the inertness of the styrene polymer backbone in the investigation of electron transfer mechanisms. Alkaline pulping experiments showed that close contact between the redox active side chains in the copolymers was fundamental for an efficient degradation of the β-O-4 lignin model units, highlighting the importance of electron transfer reactions in the lignin degradation mechanisms catalyzed by AQ. In the absence of glucose, AQ units oxidized phenolic β-O-4 lignin model parts, mainly by electron transfer leading to vanillin as major product. By contrast, in presence of glucose, anthrahydroquinone units (formed by reduction of AQ) reduced the quinone-methide units (issued by dehydration of phenolic β-O-4 lignin model part) mainly by electron transfer leading to guaiacol as major product. Both processes were distance dependent.

  2. SYNTHESIS, REACTIVITY AND BIOLOGICAL ACTIVITY OF QUINOXALIN-2-ONE DERIVATIVES

    El Mokhtar Essassi

    2010-04-01

    Full Text Available Quinoxalines have a great interest in various fields and particularly in chemistry, biology and pharmacology. It enabled the researchers to develop many methods for their preparations and to seek new fields of application. In this review, we’ll expose different methods of synthesis of the quinoxalin-2-one, its reactivity and finally we’ll discuss the various biological activities of its derivatives.

  3. Synthesis, properties and reactivity of intramolecular hypercoordinate silicon complexes

    Nikolin, A A; Negrebetsky, V V

    2014-01-01

    The state of the art of the chemistry of hypercoordinate silicon compounds is analyzed. Published data on the current top-priority approaches to the preparative synthesis of these compounds and on their properties, structures and reactivity are summarized and generalized. Relying on the results obtained by modern physicochemical methods, the possible mechanisms of stereodynamic processes occurring in the coordination units of hypercoordinate silicon complexes are discussed. The bibliography includes 157 references

  4. A multi-paradigm language for reactive synthesis

    Ioannis Filippidis

    2016-02-01

    Full Text Available This paper proposes a language for describing reactive synthesis problems that integrates imperative and declarative elements. The semantics is defined in terms of two-player turn-based infinite games with full information. Currently, synthesis tools accept linear temporal logic (LTL as input, but this description is less structured and does not facilitate the expression of sequential constraints. This motivates the use of a structured programming language to specify synthesis problems. Transition systems and guarded commands serve as imperative constructs, expressed in a syntax based on that of the modeling language Promela. The syntax allows defining which player controls data and control flow, and separating a program into assumptions and guarantees. These notions are necessary for input to game solvers. The integration of imperative and declarative paradigms allows using the paradigm that is most appropriate for expressing each requirement. The declarative part is expressed in the LTL fragment of generalized reactivity(1, which admits efficient synthesis algorithms, extended with past LTL. The implementation translates Promela to input for the Slugs synthesizer and is written in Python. The AMBA AHB bus case study is revisited and synthesized efficiently, identifying the need to reorder binary decision diagrams during strategy construction, in order to prevent the exponential blowup observed in previous work.

  5. Flavonoids: hemisynthesis, reactivity, characterization and free radical scavenging activity.

    Es-Safi, Nour-Eddine; Ghidouche, Souhila; Ducrot, Paul Henri

    2007-09-26

    Phenolic compounds form one of the main classes of secondary metabolites. They display a large range of structures and they are responsible for the major organoleptic characteristics of plant-derived-foods and beverages, particularly color and taste properties and they also contribute to the nutritional qualities of fruits and vegetables. Phenolic compounds are also highly unstable compounds which undergo numerous enzymatic and chemical reactions during postharvest food storage and processing thus adding to the complexity of plant polyphenol composition. Among these compounds flavonoids constitute one of the most ubiquitous groups of all plant phenolics. Owing to their importance in food organoleptic properties and in human health, a better understanding of their structures, their reactivity and chemical properties in addition to the mechanisms generating them appears essential to predict and control food quality. The purpose of this work is an overview of our findings concerning the hemisynthesis, the reactivity and the enzymatic oxidation of some flavonoids and shed light on the mechanisms involved in some of these processes and the structures of the resulting products. The free radical scavenging activity of some of the synthesized compounds is also presented and a structure-activity relationship is discussed. The first part of this review concerns the synthesis and structural characterization of modified monomeric flavanols. The use of these compounds as precursor for the preparation of natural and modified dimeric procyanidin derivatives was then explored through different coupling reactions. The full characterization of the synthesized compounds was achieved by concerted use of NMR and ESI-MS techniques. The free radical scavenging activity of some of the synthesized compounds was investigated. The second part of this review concerns the enzymatic oxidation of several flavonols by Trametes versicolor laccase. Most of the major oxidation products have been

  6. Flavonoids: Hemisynthesis, Reactivity, Characterization and Free Radical Scavenging Activity

    Paul Henri Ducrot

    2007-09-01

    Full Text Available Phenolic compounds form one of the main classes of secondary metabolites. They display a large range of structures and they are responsible for the major organoleptic characteristics of plant-derived-foods and beverages, particularly color and taste properties and they also contribute to the nutritional qualities of fruits and vegetables. Phenolic compounds are also highly unstable compounds which undergo numerous enzymatic and chemical reactions during postharvest food storage and processing thus adding to the complexity of plant polyphenol composition. Among these compounds flavonoids constitute one of the most ubiquitous groups of all plant phenolics. Owing to their importance in food organoleptic properties and in human health, a better understanding of their structures, their reactivity and chemical properties in addition to the mechanisms generating them appears essential to predict and control food quality. The purpose of this work is an overview of our findings concerning the hemisynthesis, the reactivity and the enzymatic oxidation of some flavonoids and shed light on the mechanisms involved in some of these processes and the structures of the resulting products. The free radical scavenging activity of some of the synthesized compounds is also presented and a structure-activity relationship is discussed. The first part of this review concerns the synthesis and structural characterization of modified monomeric flavanols. The use of these compounds as precursor for the preparation of natural and modified dimeric procyanidin derivatives was then explored through different coupling reactions. The full characterization of the synthesized compounds was achieved by concerted use of NMR and ESI-MS techniques. The free radical scavenging activity of some of the synthesized compounds was investigated. The second part of this review concerns the enzymatic oxidation of several flavonols by Trametes versicolor laccase. Most of the major oxidation

  7. Synthesis and characterization of Taurine

    B Bayarmaa

    2014-10-01

    Full Text Available Have been obtained 2-aminoethanesulfonic acid (taurine from ethanolamine, sulfuric acid and sodium sulfite during the synthesis in laboratory condition. The process involves two steps of reactions, the first was esterification of ethanolamine with sulfuric acid to produce the intermediate product of 2-aminoethyl ester which than was extended to the second step by sulfonation with sodium sulfite to produce 2-aminoethanesulfonic acid. Resulting product was analyzed using 1H-NMR, IR, FAB-MS analysis and examined purity characterizations of the synthesized products. DOI: http://dx.doi.org/10.5564/mjc.v14i0.200 Mongolian Journal of Chemistry 14 (40, 2013, p57-60

  8. Synthesis, Properties Characterization and Applications of Various Organobismuth Compounds

    Jingfei Luan

    2011-05-01

    Full Text Available Organobismuth chemistry was emphasized in this review article due to the low price, low toxicity and low radioactivity characteristics of bismuth. As an environmentally-friendly class of organometallic compounds, different types of organobismuth compounds have been used in organic synthesis, catalysis, materials, etc. The synthesis and property characterization of many organobismuth compounds had been summarized. This review article also presented a survey of various applications of organobismuth compounds in organic transformations, as reagents or catalysts. The reactivity, reaction pathways and mechanisms of reactions with organobismuths were discussed. Less common and limiting aspects of organobismuth compounds were also briefly mentioned.

  9. Synthesis of functional nanocrystallites through reactive thermal plasma processing

    Takamasa Ishigaki and Ji-Guang Li

    2007-01-01

    Full Text Available A method of synthesizing functional nanostructured powders through reactive thermal plasma processing has been developed. The synthesis of nanosized titanium oxide powders was performed by the oxidation of solid and liquid precursors. Quench gases, either injected from the shoulder of the reactor or injected counter to the plasma plume from the bottom of the reactor, were used to vary the quench rate, and therefore the particle size, of the resultant powders. The experimental results are well supported by numerical analysis on the effects of the quench gas on the flow pattern and temperature field of the thermal plasma as well as on the trajectory and temperature history of the particles. The plasma-synthesized TiO2 nanoparticles showed phase preferences different from those synthesized by conventional wet-chemical processes. Nanosized particles of high crystallinity and nonequilibrium chemical composition were formed in one step via reactive thermal plasma processing.

  10. Polymer Brushes: Synthesis, Characterization, Applications

    Advincula, Rigoberto C.; Brittain, William J.; Caster, Kenneth C.; Rühe, Jürgen

    2004-09-01

    Materials scientists, polymer chemists, surface physicists and materials engineers will find this book a complete and detailed treatise on the field of polymer brushes, their synthesis, characterization and manifold applications. In a first section, the various synthetic pathways and different surface materials are introduced and explained, followed by a second section covering important aspects of characterization and analysis in both flat surfaces and particles. These specific surface initiated polymerization (SIP) systems such as linear polymers, homopolymers, block copolymers, and hyperbranched polymers are unique compared to previously reported systems by chemisorption or physisorption. They have found their way in both large-scale and miniature applications of polymer brushes, which is covered in the last section. Such 'hairy' surfaces offer fascinating opportunities for addressing numerous problems of both academic and, in particular, industrial interest: high-quality, functional or protective coatings, composite materials, surface engineered particles, metal-organic interfaces, biological applications, micro-patterning, colloids, nanoparticles, functional devices, and many more. It is the desire of the authors that this book will be of benefit to readers who want to "brush-up on polymers".

  11. Synthesis of Reactive Polymers for Acrolein Capture Using AGET ATRP.

    Beringer, Laura T; Li, Shaohua; Gilmore, Gary; Lister, John; Averick, Saadyah

    2015-10-05

    Acrolein is a toxic metabolite of the anticancer agent cyclophosphamide (CP). Current strategies to mitigate acrolein toxicity are insufficient, and in this brief article, we report the synthesis of well-defined low molecular weight block copolymers using activators generated by electron transfer atom transfer radical polymerization (AGET ATRP) capable of reacting with the cytotoxic small molecule acrolein. Acrolein reactivity was introduced into the block copolymers via incorporation of either (a) aminooxy or (b) sulfhydryl groups. The cytoprotective effect of the polymers was compared to sodium 2-sulfanylethanesulfonate (mesna) the current gold standard for protection from CP urotoxicity, and we found that the polymers bearing sulfhydryl moieties demonstrated superior cytoprotective activity.

  12. Low-reactive circulating fluidized bed combustion (CFBC) fly ashes as source material for geopolymer synthesis

    Xu Hui; Li Qin; Shen Lifeng; Zhang Mengqun; Zhai Jianping

    2010-01-01

    In this contribution, low-reactive circulating fluidized bed combustion (CFBC) fly ashes (CFAs) have firstly been utilized as a source material for geopolymer synthesis. An alkali fusion process was employed to promote the dissolution of Si and Al species from the CFAs, and thus to enhance the reactivity of the ashes. A high-reactive metakaolin (MK) was also used to consume the excess alkali needed for the fusion. Reactivities of the CFAs and MK were examined by a series of dissolution tests in sodium hydroxide solutions. Geopolymer samples were prepared by alkali activation of the source materials using a sodium silicate solution as the activator. The synthesized products were characterized by mechanical testing, scanning electron microscopy (SEM), X-ray diffractography (XRD), as well as Fourier transform infrared spectroscopy (FTIR). The results of this study indicate that, via enhancing the reactivity by alkali fusion and balancing the Na/Al ratio by additional aluminosilicate source, low-reactive CFAs could also be recycled as an alternative source material for geopolymer production.

  13. Block of glucocorticoid synthesis during re-activation inhibits extinction of an established fear memory.

    Blundell, Jacqueline; Blaiss, Cory A; Lagace, Diane C; Eisch, Amelia J; Powell, Craig M

    2011-05-01

    The pharmacology of traumatic memory extinction has not been fully characterized despite its potential as a therapeutic target for established, acquired anxiety disorders, including post-traumatic stress disorder (PTSD). Here we examine the role of endogenous glucocorticoids in traumatic memory extinction. Male C57BL/6J mice were injected with corticosterone (10 mg/kg, i.p.) or metyrapone (50 mg/kg, s.c.) during re-activation of a contextual fear memory, and compared to vehicle groups (N=10-12 per group). To ensure that metyrapone was blocking corticosterone synthesis, we measured corticosterone levels following re-activation of a fear memory in metyrapone- and vehicle-treated animals. Corticosterone administration following extinction trials caused a long-lasting inhibition of the original fear memory trace. In contrast, blockade of corticosteroid synthesis with metyrapone prior to extinction trials enhanced retrieval and prevented extinction of context-dependent fear responses in mice. Further behavioral analysis suggested that the metyrapone enhancement of retrieval and prevention of extinction were not due to non-specific alterations in locomotor or anxiety-like behavior. In addition, the inhibition of extinction by metyrapone was rescued by exogenous administration of corticosterone following extinction trials. Finally, we confirmed that the rise in corticosterone during re-activation of a contextual fear memory was blocked by metyrapone. We demonstrate that extinction of a classical contextual fear memory is dependent on endogenous glucocorticoid synthesis during re-activation of a fear memory. Our data suggest that decreased glucocorticoids during fear memory re-activation may contribute to the inability to extinguish a fear memory, thus contributing to one of the core symptoms of PTSD. Copyright © 2011 Elsevier Inc. All rights reserved.

  14. Process Improvement of Reactive Dye Synthesis Using Six Sigma Concept

    Suwanich, Thanapat; Chutima, Parames

    2017-06-01

    This research focuses on the problem occurred in the reactive dye synthesis process of a global manufacturer in Thailand which producing various chemicals for reactive dye products to supply global industries such as chemicals, textiles and garments. The product named “Reactive Blue Base” is selected in this study because it has highest demand and the current chemical yield shows a high variation, i.e. yield variation of 90.4% - 99.1% (S.D. = 2.405 and Cpk = -0.08) and average yield is 94.5% (lower than the 95% standard set by the company). The Six Sigma concept is applied aiming at increasing yield and reducing variation of this process. This approach is suitable since it provides a systematic guideline with five improvement phases (DMAIC) to effectively tackle the problem and find the appropriate parameter settings of the process. Under the new parameter settings, the process yield variation is reduced to range between 96.5% - 98.5% (S.D. = 0.525 and Cpk = 1.83) and the average yield is increased to 97.5% (higher than the 95% standard set by the company).

  15. Synthesis, characterization and comparison of polythiophene ...

    38

    Synthesis, characterization and comparison of polythiophene-carbon ... b Nanotechnology Research Institute, School of Chemical Engineering, Babol University of Technology, Babol, ..... The scan range was from −0.24 to 1.2 V in reference to.

  16. Reactive synthesis of NbAl3 matrix composites

    Lu, L.; Kim, Y.S.; Gokhale, A.B.; Abbaschian, R.

    1990-01-01

    NbAl 3 matrix composites were synthesized in-situ via reactive hot compaction (RHC) of elemental powders. It was found that the simultaneous application of pressure during synthesis was effective in attaining a near-theoretical density matrix at relatively low temperatures and pressures. Using this technique, two types of composites were produced: matrices containing a uniform dispersion of second phase particles (either Nb 3 Al or Nb 2 Al with an Nb core or Nb 2 Al) and matrices reinforced with coated or uncoated ductile Nb filaments. It was found that a limited amount of toughening is obtained using the first approach, while composites containing coated Nb filaments exhibited a significant increase in the ambient temperature fracture toughness. In this paper, various aspects of RHC processing of NbAl 3 matrix composites, the effect of initial stoichiometry and powder size on the microstructure, as well as the mechanical behavior of the composites are discussed

  17. Synthesis of gallium nitride and related oxides via ammonobasic reactive sublimation (ARS)

    Hernández-Hernández, Luis Alberto; Aguilar-Hernández, Jorge R.; Mejía-García, Concepción; Cruz-Gandarilla, Francisco; Contreras-Puente, Gerardo [Escuela Superior de Física y Matemáticas, Instituto Politécnico Nacional, Ciudad de México (Mexico); Moure-Flores, Francisco de [Facultad de Química, Materiales-Energía, Universidad Autónoma de Querétaro (Mexico); Melo-Pereira, Osvaldo de, E-mail: schwarzerengelxv@hotmail.com [Facultad de Física, Universidad de La Habana, La Habana (Cuba)

    2017-11-15

    Ammonobasic reactive sublimation (ARS) is proposed as a novel method to synthesize GaN and related oxides. Results indicate that GaN growth occurs by a nitriding process of Ga and related oxides, establishing a direct dependence on NH{sub 4} OH amount added as a primary chemical reactive. The samples were grown on p-type Si (111) substrates inside a tube furnace, employing GaN powder and NH{sub 4} OH. The characterizations of the samples were carried out by XRD, SEM, EDS and PL techniques, revealing the influence of NH{sub 4} OH on the improvement of GaN synthesis and the enhancement of its optical and structural properties. (author)

  18. SYNTHESIS, CHARACTERIZATION AND DENSITY FUNCTIONAL ...

    Preferred Customer

    We synthesized a number of aniline derivatives containing acyl groups to compare their barriers of rotation around ... KEY WORDS: Monoacyl aniline, Synthesis, Density functional theory, Rotation barrier. INTRODUCTION. Developments in ...

  19. SYNTHESIS AND CHARACTERIZATION OF FUNCTIONALIZED ...

    In addition, these compounds have emerged as potential calcium ... As a consequence, the synthesis of dihydropyrimidinone derivatives has ..... Ramazani, A.; Shaghaghi,Z.; Aghahosseini, H.; Asiabi, P.A.; Joo, S.W. Silica nanoparticles.

  20. Synthesis, characterization and antimicrobial activity of mixed ...

    Synthesis, characterization and antimicrobial activity of mixed ascorbic acid - nicotinamide metal complexes. ... The result of the antimicrobial studies showed that the mixed complexes have higher inhibitory activity than the original ligands against the tested bacteria and fungi species. KEY WORDS: Ascorbic acid, ...

  1. Synthesis, characterization, antimicrobial activity and molecular ...

    Synthesis, characterization, antimicrobial activity and molecular docking studies of combined pyrazol-barbituric acid pharmacophores. Assem Barakat, Bandar M. Al-Qahtani, Abdullah M. Al-Majid, M. Ali Mohammed Rafi Shaik, Mohamed H.M. Al-Agamy, Abdul Wadood ...

  2. Synthesis, Characterization, Antimicrobial Activity and Antioxidant ...

    MBI

    2015-12-08

    Dec 8, 2015 ... Synthesis, Characterization, Antimicrobial Activity and Antioxidant. Studies of ... Transition metal complexes of Co(II) and Ni(II) with Schiff base ligand (HL) derived from condensation of 2- ..... 2-((5mercapto-1,3,4-thiadiazol-2-.

  3. Synthesis and characterization of five-coordinated indium amidinates

    Riahi, Yasaman

    2016-07-29

    The focus of this work is synthesis, characterization and exploring the reactivity of new indium amidinate compounds of the type R{sub 2}InX (R = R''NCR'NR''; R' = Ph, R'' = SiMe{sub 3}, iPr, dipp; X = Br, Cl) with the coordination number of five and R{sub 3}In (R = Me{sub 3}SiNCPhNSiMe{sub 3}) with the coordination number of six. By using amidinates as chelating ligands the electron deficiency of indium atom will be resolved. Additionally, by using different substituents the study of the different synthesized indium amidinates has become possible. The selected method for the synthesis allows the carbodiimides to react with organolithium compounds to get the corresponding lithium amidinates. Afterwards the resulting lithium amidinates take part in transmetalation reactions with InBr{sub 3} and InCl{sub 3}. The study of the reactivity of indium amidinate complexes including nucleophilic reactions as well as their reduction were also examined. Beside crystal structure analysis, nuclear magnetic resonance spectroscopy as well as elemental analysis has been applied to characterize the compounds.

  4. Synthesis, Reactivity and Stability of Aryl Halide Protecting Groups towards Di-Substituted Pyridines

    Ptoton Mnangat Brian

    2016-03-01

    Full Text Available This paper reports the synthesis and reactivity of different Benzyl derivative protecting groups. The synthesis and stability of Benzyl halides, 4-methoxybenzyl halides, 3,5-dimethoxybenzyl halides, 3,4-dimethoxybenzyl halides, 3,4,5-trimethoxybenzyl halide protecting groups and their reactivity towards nitrogen atom of a di-substituted pyridine ring in formation of pyridinium salts is also reported.

  5. Synthesis and Characterization of Colloidal Metal and Photovoltaic Semiconductor Nanocrystals

    Abulikemu, Mutalifu

    2014-11-05

    Metal and semiconducting nanocrystals have received a great deal of attention from fundamental scientists and application-oriented researchers due to their physical and chemical properties, which differ from those of bulk materials. Nanocrystals are essential building blocks in the development of nanostructured devices for energy conversion. Colloidal metals and metal chalcogenides have been developed for use as nanocrystal inks to produce efficient solar cells with lower costs. All high-performing photovoltaic nanocrystals contain toxic elements, such as Pb, or scarce elements, such as In; thus, the production of solution-processable nanocrystals from earth-abundant materials using environmentally benign synthesis and processing methods has become a major challenge for the inorganic semiconductor-based solar field. This dissertation, divided into two parts, addresses several aspects of these emerging challenges. The first portion of the thesis describes the synthesis and characterization of nanocrystals of antimony sulfide, which is composed of non-scarce and non-toxic elements, and examines their performance in photovoltaic devices. The effect of various synthetic parameters on the final morphology is explored. The structural, optical and morphological properties of the nanocrystals were investigated, and Sb2S3 nanocrystal-based solid-state semiconductor-sensitized solar cells were fabricated using different deposition processes. We achieved promising power conversion efficiencies of 1.48%. The second part of the thesis demonstrates a novel method for the in situ synthesis and patterning of nanocrystals via reactive inkjet printing. The use of low-cost manufacturing approaches for the synthesis of nanocrystals is critical for many applications, including photonics and electronics. In this work, a simple, low-cost method for the synthesis of nanocrystals with minimum size variation and waste using reactive inkjet printing is introduced. As a proof of concept, the

  6. Synthesis, characterization, photoluminescence and thermally ...

    Administrator

    X-ray diffraction and scanning electron microscopy to identify the crystalline phase and determine the parti- cle size. ... Spectral characteristics of the TSL glow showed emission around 565, 599 and. 641 nm, indicating ... thesis and characterization of rare-earth-doped ZnAl2O4 ..... Other researchers have reported similar.

  7. Development of a model for the synthesis of unsaturated polyester by reactive distillation

    Shah, M.R.; Zondervan, E.; Oudshoorn, M.L.; Haan, de A.B.; Haan, de A.B.; Kooijman, H.; Górak, A.

    2010-01-01

    Traditionally polyester production is done in a batch reactor equipped with a separation column for batch distillation. A promising alternative for the intensification of this process is reactive distillation. In this paper, a reactive distillation model is developed for the synthesis of an

  8. synthesis and optical characterization of acid-doped polyaniline thin

    HOD

    SYNTHESIS AND OPTICAL CHARACTERIZATION OF ACID-DOPED. POLYANILINE THIN .... MATERIALS AND METHODS .... Characterization of Se Doped Polyaniline”,Current. Applied ... with Silver Nanoparticles”, Advances in Materials.

  9. Reactive distillation: an attractive alternative for the synthesis of unsaturated polyester

    Shah, M.R.; Zondervan, E.; Oudshoorn, M.L.; Haan, de A.B.

    2011-01-01

    Unsaturated polyester is traditionally produced in a batch wise operating reaction vessel connected to a distillation unit. An attractive alternative for the synthesis of unsaturated polyester is a reactive distillation. To value such alternative synthesis route reliable process models need to be

  10. The Synthesis, Characterization and Catalytic Reaction Studies of Monodisperse Platinum Nanoparticles in Mesoporous Oxide Materials

    Rioux, Robert M. [Univ. of California, Berkeley, CA (United States)

    2006-01-01

    A catalyst design program was implemented in which Pt nanoparticles, either of monodisperse size and/or shape were synthesized, characterized and studied in a number of hydrocarbon conversion reactions. The novel preparation of these materials enables exquisite control over their physical and chemical properties that could be controlled (and therefore rationally tuned) during synthesis. The ability to synthesize rather than prepare catalysts followed by thorough characterization enable accurate structure-function relationships to be elucidated. This thesis emphasizes all three aspects of catalyst design: synthesis, characterization and reactivity studies. The precise control of metal nanoparticle size, surface structure and composition may enable the development of highly active and selective heterogeneous catalysts.

  11. Photocatalytic semiconductors synthesis, characterization, and environmental applications

    Hernández-Ramírez, Aracely

    2014-01-01

    This critical volume examines the different methods used for the synthesis of a great number of photocatalysts, including TiO2, ZnO and other modified semiconductors, as well as characterization techniques used for determining the optical, structural and morphological properties of the semiconducting materials. Additionally, the authors discuss photoelectrochemical methods for determining the light activity of the photocatalytic semiconductors by means of measurement of properties such as band gap energy, flat band potential and kinetics of hole and electron transfer. Photocatalytic Semiconductors: Synthesis, Characterization and Environmental Applications provide an overview of the semiconductor materials from first- to third-generation photocatalysts and their applications in wastewater treatment and water disinfection. The book further presents economic and toxicological aspects in the production and application of photocatalytic materials.

  12. Polypyrrole-silver Nanocomposite: Synthesis and Characterization

    D. M. Nerkar; S. V. Panse; S. P. Patil; S. E. Jaware; G. G. Padhye

    2016-01-01

    Polypyrrole-Silver (PPy-Ag) nanocomposite has been successfully synthesized by the chemical oxidative polymerization of pyrrole with iron (III) chloride as an oxidant, in the presence of a colloidal suspension of silver nanoparticles. Turkevich method (Citrate reduction method) was used for the synthesis of silver nanoparticles (Ag NPs). The silver nanoparticles were characterized by UV-Visible spectroscopy which showed an absorption band at 423 nm confirming the formation of nanoparticles. P...

  13. Synthesis, structural and electrical characterizations of thermally ...

    Synthesis, structural and electrical characterizations of thermally evaporated Cu 2 SnS 3 thin films. ... The surface profilometer shows that the deposited films are rough. The XRD spectra identified the ... The electrical resistivity of the deposited Cu2SnS3 film is 2.55 x 10-3 Ωcm. The conductivity is in the order of 103 Ω-1cm-1.

  14. Synthesis and Reactivity of Tripodal Complexes Containing Pendant Bases

    Blacquiere, Johanna M.; Pegis, Michael L.; Raugei, Simone; Kaminsky, Werner; Forget, Amelie; Cook, Sarah; Taguchi, Taketo; Borovik, Andrew S.; Mayer, James M.

    2014-09-02

    The synthesis of a new tripodal ligand family is reported, with tertiary-amine groups in the second-coordination sphere. The ligands are tris(amido)amine derivatives, with the pendant amines attached via a peptide coupling strategy. They were designed to be used in new catalysts for the oxygen reduction reaction (ORR), in which the pendant acid/base group could improve catalyst performance. Two members of the new ligand family were each metallated with Co(II) and Zn(II) to afford trigonal monopyramidal complexes. Reaction of the cobalt complexes, [Co(L)]-, with dioxygen reversibly generates a small amount of a Co(III)-superoxo species, which was characterized by EPR. Protonation of the zinc complex Zn[N{CH2CH2NC(O)CH2N(CH2Ph)2}3)-– ([Zn(TNBn)]-) with one equivalent of acid occurs with displacement and dissociation of an amide ligand. Addition of excess acid to the any of the complexes [M(L)]- results in complete proteolysis and formation of the ligands H3L. This decomposition limits the use of these complexes as catalysts for the ORR. An alternative ligand with two pyridyl arms was also prepared but could not be metallated. These studies highlight the importance of stability of the primary-coordination sphere of ORR electrocatalysts to both oxidative and acidic conditions. This research was supported as part of the Center for Molecular Electrocatalysis, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences.

  15. Synthesis and characterization of iron cobalt (FECO) nanorods ...

    Synthesis and characterization of iron cobalt (FECO) nanorods prepared by simple ... shaped by increasing annealing temperature from room temperature to 800 ... Keywords: FeCo nanoparticles, sodium borohydrid, CTAB, chemical synthesis ...

  16. Synthesis and characterization of nano silicon and titanium nitride ...

    The characterization techniques indicated ... Scalable synthesis; microwave plasma; chemical synthesis; nanoparticles. 1. Introduction ... used but very few methods are available to produce silicon and titanium ... current (A). (m3/h). 1. Si. 2.1.

  17. Synthesis, Spectroscopic and DFT Characterization of 4â-(4-tert ...

    In this work the synthesis, spectral characterization and non-linear optical properties of metal-free .... following literature methods23–26 The advantage of this method ..... Synthesis of phthalocyanine conjugates with gold nanoparticles and.

  18. Synthesis and characterization of new ionic liquids

    Oliveira, L.M.C. de; Mattedi, S.; Boaventura, J.S.; Iglesias, M.; Universidad de Santiago de Compostela

    2010-01-01

    In recent years, ionic liquids have been highlighted for its potential in various industrial applications. Among them, the salts of Broensted has a promising profile for the low toxicity, low cost and simple synthesis. This paper presents the synthesis and characterization of new salts of Bronsted with branched (lactate) or large chain anions (oleate) for future use as additives promoters of proton conductivity in fuel cells of ethanol. Experimental data were measured for density, sound velocity and conductivity of pure ionic liquids and mixtures. The density decreases linearly with increasing temperature, and sound velocity shows a similar trend, but not linear. The conductivity increases according to the Arrhenius model with activation energy less than 10 J/mol. Tests NMR, FTIR and TGA confirm ionic structure and thermal stability up to 165 deg C. (author)

  19. SYNTHESIS AND CHARACTERIZATION OF NEW HALOGENATED CURCUMINOIDS

    Eugenio Torres

    2013-12-01

    Full Text Available In this work a novel procedure of synthesis of compounds analogues to curcumin with halogens atoms in its structure is described, which can increase its solubility and biological activity. Four halogenated curcuminoids were obtained with great pharmacological interest, none of them reported in literature before. Synthesis was carried out by means of the aldol condensation assisted by microwaves of halogenated aromatic aldehydes and acetylacetona, using morpholine as basic catalyst, in absence of solvent, and the reaction just needed 1 min. The products were purified by treatment of the reaction mixture with methanol under ultrasound irradiation, followed by chromatographic column. All obtained compounds were characterized by infrared spectroscopy, nuclear magnetic resonance, quantitative elementary analysis and high resolution mass spectrometry. The RMN-1H data demonstrate in all structures of synthesized curcuminoids the enol form is the most favored.

  20. Characterization and reactivity of sodium aluminoborosilicate glass fiber surfaces

    Ortiz Rivera, Lymaris, E-mail: luo105@psu.edu [Materials Research Institute, Pennsylvania State University, University Park, PA 16802 (United States); Bakaev, Victor A.; Banerjee, Joy [Materials Research Institute, Pennsylvania State University, University Park, PA 16802 (United States); Mueller, Karl T. [Department of Chemistry, Pennsylvania State University, University Park, PA 16802 (United States); Pantano, Carlo G. [Materials Research Institute, Pennsylvania State University, University Park, PA 16802 (United States); Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA 16802 (United States)

    2016-05-01

    Highlights: • XPS revealed that these fiber surfaces contain sodium carbonate weathering products. • IGC–MS data confirms the products of acetic acid reaction with sodium carbonate. • NMR data shows two closely spaced, but distinct sodium carboxylate peaks. • Acetic acid reacts with both sodium in the glass and sodium in the sodium carbonate. - Abstract: Multicomponent complex oxides, such as sodium aluminoborosilicate glass fibers, are important materials used for thermal insulation in buildings and homes. Although the surface properties of single oxides, such as silica, have been extensively studied, less is known about the distribution of reactive sites at the surface of multicomponent oxides. Here, we investigated the reactivity of sodium aluminoborosilicate glass fiber surfaces for better understanding of their interface chemistry and bonding with acrylic polymers. Acetic acid (with and without a {sup 13}C enrichment) was used as a probe representative of the carboxylic functional groups in many acrylic polymers and adhesives. Inverse gas chromatography coupled to a mass spectrometer (IGC–MS), and solid state nuclear magnetic resonance (NMR), were used to characterize the fiber surface reactions and surface chemical structure. In this way, we discovered that both sodium ions in the glass surface, as well as sodium carbonate salts that formed on the surface due to the intrinsic reactivity of this glass in humid air, are primary sites of interaction with the carboxylic acid. Surface analysis by X-ray photoelectron spectroscopy (XPS) confirmed the presence of sodium carbonates on these surfaces. Computer simulations of the interactions between the reactive sites on the glass fiber surface with acetic acid were performed to evaluate energetically favorable reactions. The adsorption reactions with sodium in the glass structure provide adhesive bonding sites, whereas the reaction with the sodium carbonate consumes the acid to form sodium-carboxylate, H

  1. Graphene optoelectronics synthesis, characterization, properties, and applications

    bin M Yusoff, Abdul Rashid

    2014-01-01

    This first book on emerging applications for this innovative material gives an up-to-date account of the many opportunities graphene offers high-end optoelectronics.The text focuses on potential as well as already realized applications, discussing metallic and passive components, such as transparent conductors and smart windows, as well as high-frequency devices, spintronics, photonics, and terahertz devices. Also included are sections on the fundamental properties, synthesis, and characterization of graphene. With its unique coverage, this book will be welcomed by materials scientists, solid-

  2. Lanthanide alkyl and silyl compounds: Synthesis, reactivity and catalysts for green

    Pindwal, Aradhana [Iowa State Univ., Ames, IA (United States)

    2016-01-01

    The last few decades have witnessed enormous research in the field of organometallic lanthanide chemistry. Our research group has developed a few rare earth alkyl compounds containing tris(dimethylsilyl)methyl ligand and explored their reactivity. This thesis focusses on extending the study of lanthanide alkyl and silyl compounds to develop strategies for their synthesis and explore their reactivity and role as catalysts in processes such as hydrosilylation and cross-dehydrocoupling.

  3. Synthesis and Characterization of Novel Quaternary Thioaluminogermanates

    Al-Bloushi, Mohammed

    2013-05-01

    Metal chalcogenides form an important class of inorganic materials, which include several technologically important applications. The design of metal chlcogenides is of technological interest and has encouraged recent research into moderate temperature solid-state synthetic methods for the single crystal growth of new materials. The aim of this project is the investigation and development of synthetic methodology for the synthesis of novel metal chlcogenides. The new inorganic compounds of the type “M(AlS2)(GeS2)” (M = Na and K) are new metal-chalcogenides, synthesized by the classical solid state approach. The characterization of these compounds was carried out by Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDS), Single crystal and powder X-ray diffraction, solid state Nuclear Magnetic Resonance (NMR), Ultraviolet-visible (UV-VIS), Infrared (IR) and Raman spectroscopy. These theses study the synthesis of metal chalcogenides through the use of standard chemical techniques. The systematic studies demonstrate the effect of the reactants ratio and reaction temperature on the synthesis and growth of the single crystals. Metal chalcogenides have several potential applications in gas separation, ion exchange, environmental remediation, and energy storage. Especially, the ion exchange materials have found\\tpossible applications in waste-water treatment, water softening, metal separation, and production of high purity water.

  4. Design and synthesis of reactive separation systems. Final report

    Doherty, M.F.

    1992-12-31

    During the last decade there has been a rapid upturn in interest in reactive distillation. The chemical process industry recognizes the favorable economics of carrying out reaction simultaneously with distillation for certain classes of reacting systems, and many new processes have been built based on this technology. Interest is also increasing by academics and software vendors. Systematic design methods for reactive distillation systems have only recently begun to emerge. In this report we survey the available design techniques and point out the contributions made by our group at the University of Massachusetts.

  5. Reactivation of herpes simplex virus in a cell line inducible for simian virus 40 synthesis

    Zamansky, G.B.; Kleinman, L.F.; Black, P.H.; Kaplan, J.C.

    1980-01-01

    The reactivation of UV-irradiated herpes simplex virus (HSV) was investigated in irradiated and unirradiated transformed hamster cells in which infectious simian virus 40(SV40) can be induced. Reactivation was enhanced when the cells were treated with UV light or mitomycin C prior to infection with HSV. The UV dose-response curve of this enhanced reactivation was strikingly similar to that found for induction of SV40 virus synthesis in cells treated under identical conditions. This is the first time that two SOS functions described in bacteria have been demonstrated in a single mammalian cell line. (orig.)

  6. Synthesis and processing of composites by reactive metal penetration

    Loehman, R.E.; Ewsuk, K.G. [Sandia National Laboratories, Albuquerque, NM (United States); Tomsia, A.P. [Pask Research and Engineering, Berkeley, CA (United States)] [and others

    1995-05-01

    Ceramic-metal composites are being developed because their high stiffness-to weight ratios, good fracture toughness, and variable electrical and thermal properties give them advantages over more conventional materials. However, because ceramic-metal composite components presently are more expensive than monolithic materials, improvements in processing are required to reduce manufacturing costs. Reactive metal penetration is a promising new method for making ceramic- and metal-matrix composites that has the advantage of being inherently a net-shape process. This technique, once fully developed, will provide another capability for manufacturing the advanced ceramic composites that are needed for many light-weight structural and wear applications. The lower densities of these composites lead directly to energy savings in use. Near-net-shape fabrication of composite parts should lead to additional savings because costly and energy intensive grinding and machining operations are significantly reduced, and the waste generated from such finishing operations is minimized. The goals of this research program are: (1) to identify feasible compositional systems for making composites by reactive metal penetration; (2) to understand the mechanism(s) of composite formation by reactive metal penetration; and (3) to learn how to control and optimize reactive metal penetration for economical production of composites and composite coatings.

  7. Surface characterization after subaperture reactive ion beam etching

    Miessler, Andre; Arnold, Thomas; Rauschenbach, Bernd [Leibniz-Institut fuer Oberflaechenmodifizierung (IOM), Leipzig (Germany)

    2010-07-01

    In usual ion beam etching processes using inert gas (Ar, Xe, Kr..) the material removal is determined by physical sputtering effects on the surface. The admixture of suitable gases (CF{sub 4}+O{sub 2}) into the glow discharge of the ion beam source leads to the generation of reactive particles, which are accelerated towards the substrate where they enhance the sputtering process by formation of volatile chemical reaction products. During the last two decades research in Reactive Ion Beam Etching (RIBE) has been done using a broad beam ion source which allows the treatment of smaller samples (diameter sample < diameter beam). Our goal was to apply a sub-aperture Kaufman-type ion source in combination with an applicative movement of the sample with respect to the source, which enables us to etch areas larger than the typical lateral dimensions of the ion beam. Concerning this matter, the etching behavior in the beam periphery plays a decisive role and has to be investigated. We use interferometry to characterize the final surface topography and XPS measurements to analyze the chemical composition of the samples after RIBE.

  8. Synthesis and Properties of Reactive Interfacial Agents for Polycaprolactone-Starch Blends

    Sugih, Asaf K.; Drijfhout, Jan. P.; Picchioni, Francesco; Janssen, Leon P. B. M.; Heeres, Hero J.

    2009-01-01

    The synthesis of two reactive interfacial agents for starch-polycaprolactone (PCL) blends, PCL-g-glycidyl methacrylate (PCL-g-GMA) and PCL-g-diethyl maleate (PCL-g-DEM) is described. The compounds were prepared by reacting a low molecular weight PCL. (M(w) 3000) with GMA or DEM in the presence of

  9. Photoluminescent silicon nanocrystals with chlorosilane surfaces - synthesis and reactivity

    Höhlein, Ignaz M. D.; Kehrle, Julian; Purkait, Tapas K.; Veinot, Jonathan G. C.; Rieger, Bernhard

    2014-12-01

    We present a new efficient two-step method to covalently functionalize hydride terminated silicon nanocrystals with nucleophiles. First a reactive chlorosilane layer was formed via diazonium salt initiated hydrosilylation of chlorodimethyl(vinyl)silane which was then reacted with alcohols, silanols and organolithium reagents. With organolithium compounds a side reaction is observed in which a direct functionalization of the silicon surface takes place.We present a new efficient two-step method to covalently functionalize hydride terminated silicon nanocrystals with nucleophiles. First a reactive chlorosilane layer was formed via diazonium salt initiated hydrosilylation of chlorodimethyl(vinyl)silane which was then reacted with alcohols, silanols and organolithium reagents. With organolithium compounds a side reaction is observed in which a direct functionalization of the silicon surface takes place. Electronic supplementary information (ESI) available: Detailed experimental procedures and additional NMR, PL, EDX, DLS and TEM data. See DOI: 10.1039/C4NR05888G

  10. Oxetanes: Recent Advances in Synthesis, Reactivity, and Medicinal Chemistry.

    Bull, James A; Croft, Rosemary A; Davis, Owen A; Doran, Robert; Morgan, Kate F

    2016-10-12

    The four-membered oxetane ring has been increasingly exploited for its contrasting behaviors: its influence on physicochemical properties as a stable motif in medicinal chemistry and its propensity to undergo ring-opening reactions as a synthetic intermediate. These applications have driven numerous studies into the synthesis of new oxetane derivatives. This review takes an overview of the literature for the synthesis of oxetane derivatives, concentrating on advances in the last five years up to the end of 2015. These methods are clustered by strategies for preparation of the ring and further derivatization of preformed oxetane-containing building blocks. Examples of the use of oxetanes in medicinal chemistry are reported, including a collation of oxetane derivatives appearing in recent patents for medicinal chemistry applications. Finally, examples of oxetane derivatives in ring-opening and ring-expansion reactions are described.

  11. ‘Umpolung’ Reactivity in Semiaqueous Amide and Peptide Synthesis

    Shen, Bo; Makley, Dawn M.; Johnston, Jeffrey N.

    2010-01-01

    The amide functional group is one of Nature’s key functional and structural elements, most notably within peptides. Amides are also key intermediates in the preparation of a diverse range of therapeutic small molecules. Its construction using available methods focuses principally upon dehydrative approaches, although oxidative and radical-based methods are representative alternatives. During the carbon-nitrogen bond forming step in most every example, the carbon and nitrogen bear electrophilic and nucleophilic character, respectively. Here we show that activation of amines and nitroalkanes with an electrophilic iodine source in wet THF can lead directly to amide products. Preliminary observations support a mechanistic construct in which reactant polarity is reversed (umpolung) during C-N bond formation relative to traditional approaches. The use of nitroalkanes as acyl anion equivalents provides a conceptually innovative approach to amide and peptide synthesis, and one that might ultimately provide for efficient peptide synthesis that is fully reliant on enantioselective methods. PMID:20577205

  12. Self-healing anticorrosive organic coating based on an encapsulated water reactive silyl ester: synthesis and proof of concept

    García, S.J.; Fischer, H.R.; White, P.A.; Mardel, J.; González-García, Y.; Mol, J.M.C.; Hughes, A.E.

    2011-01-01

    In this paper a self-healing anticorrosive organic coating based on an encapsulated water reactive organic agent is presented. A reactive silyl ester is proposed as a new organic reactive healing agent and its synthesis, performance, incorporation into an organic coating and evaluation of

  13. Synthesis and characterization of innovative insulation materials

    Skaropoulou Aggeliki

    2018-01-01

    Full Text Available Insulation elements are distinguished in inorganic fibrous and organic foamed materials. Foamed insulation materials are of great acceptance and use, but their major disadvantage is their flammability. In case of fire, they tend to transmit the flame producing toxic gases. In this paper, the synthesis and characterization of innovative inorganic insulation materials with properties competitive to commercial is presented. Their synthesis involves the mixing of inorganic raw material and water with reinforcing agent or/and foaming agent leading to the formation of a gel. Depending on raw materials nature, the insulation material is produced by freeze drying or ambient drying techniques of the gel. The raw material used are chemically benign and abundantly available materials, or industrial by-products and the final products are non-toxic and, in some cases, non-flammable. Their density and thermal conductivity was measured and found 0.02-0.06 g/cm3 and 0.03-0.04 W/mK, respectively.

  14. Green synthesis and characterization of graphene nanosheets

    Tavakoli, Farnosh [School of Chemistry, College of Science, University of Tehran, Tehran (Iran, Islamic Republic of); Salavati-Niasari, Masoud, E-mail: salavati@kashanu.ac.ir [Institute of Nano Science and Nano Technology, University of Kashan, Kashan, P. O. Box. 87317-51167, Islamic Republic of Iran (Iran, Islamic Republic of); Department of Inorganic Chemistry, Faculty of Chemistry, University of Kashan, Kashan, P. O. Box. 87317-51167, Islamic Republic of Iran (Iran, Islamic Republic of); Badiei, Alireza [School of Chemistry, College of Science, University of Tehran, Tehran (Iran, Islamic Republic of); Mohandes, Fatemeh [Department of Inorganic Chemistry, Faculty of Chemistry, University of Kashan, Kashan, P. O. Box. 87317-51167, Islamic Republic of Iran (Iran, Islamic Republic of)

    2015-03-15

    Highlights: • For the first time, we have synthesized graphene nanosheets in the presence of pomegranate juice. • Here pomegranate juice was used not only as reductant but also as capping agent. • FT-IR, XRD, SEM, EDS and TEM were used to characterize the samples. • According to TEM image, graphene nanosheet is individually exfoliated after stirring for 24 h. • As shown in the TEM image, graphene monolayer is obtained. - Abstract: For the first time, we have successfully synthesized graphene nanosheets in the presence of pomegranate juice. In this approach, pomegranate juice was used not only as reductant but also as capping agent to form graphene nanosheets. At first, the improved Hummer method to oxidize graphite for the synthesis of graphene oxide (GO) was applied, and then the as-produced graphene oxide was reduced by pomegranate juice to form graphene nanosheets. Fourier transformed infrared (FT-IR), X-ray powder diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), high resolution transmission electron microscopy (HRTEM), atomic force microscopy (AFM) and raman were used to characterize the samples. The results obtained from the characterization techniques proved high purity of the final products.

  15. Green synthesis and characterization of graphene nanosheets

    Tavakoli, Farnosh; Salavati-Niasari, Masoud; Badiei, Alireza; Mohandes, Fatemeh

    2015-01-01

    Highlights: • For the first time, we have synthesized graphene nanosheets in the presence of pomegranate juice. • Here pomegranate juice was used not only as reductant but also as capping agent. • FT-IR, XRD, SEM, EDS and TEM were used to characterize the samples. • According to TEM image, graphene nanosheet is individually exfoliated after stirring for 24 h. • As shown in the TEM image, graphene monolayer is obtained. - Abstract: For the first time, we have successfully synthesized graphene nanosheets in the presence of pomegranate juice. In this approach, pomegranate juice was used not only as reductant but also as capping agent to form graphene nanosheets. At first, the improved Hummer method to oxidize graphite for the synthesis of graphene oxide (GO) was applied, and then the as-produced graphene oxide was reduced by pomegranate juice to form graphene nanosheets. Fourier transformed infrared (FT-IR), X-ray powder diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), high resolution transmission electron microscopy (HRTEM), atomic force microscopy (AFM) and raman were used to characterize the samples. The results obtained from the characterization techniques proved high purity of the final products

  16. Synthesis and characterization of a cerebral radiotracer

    Ben hamouda, Salem

    2010-01-01

    The development of nuclear medicine is based on research of new radiopharmaceuticals, in particular, relying on technetium-99m, the most used radioisotope in terms of availability and low cost. A similar study on Rhenium (185/187Re) is essential for monitoring physico-chemical studies due to the high specific activity of technetium-99m. During this work, we have synthesized and labeled with technetium the N-methyl-4-hydroxy piperidinyl ferrocenyl carboxylate. The marking is done by exchange of ligands between the iron group of ferrocene and tricabonyl technetium core. We have succeeded to synthesis the N-methyl-4-hydroxy piperidinyl carboxyl cyclopentadienyl tricarbonyl rhenium (the molecular analogue of the technetium). We characterized it by MS, IR and NMR (1H, 13C) The structure of N-methyl-4-hydroxy piperidinyl carboxyl cyclopentadienyl tricarbonyl technetium is well justified.

  17. Synthesis and characterization of anisotropic magnetic hydrogels

    Hinrichs, Stephan, E-mail: stephan.hinrichs@chemie.uni-hamburg.de; Nun, Nils; Fischer, Birgit, E-mail: birgit.fischer@chemie.uni-hamburg.de

    2017-06-01

    Multiresponsive hydrogels are an interesting new class of materials. They offer the advantage, that they respond to different stimuli like temperature, pH and magnetic fields. By this they can change their properties which makes the hydrogels ideal candidates for many applications in the technical as well as medical field. Here we present the synthesis and characterization of hydrogels - micro- as well as macrogels - which consist of an iron oxide core, varying in phase and morphology, embedded in a thermoresponsive polymer, consisting of poly N-isopropylacrylamide. By using dynamic light scattering we investigated the thermoresponsive properties. In addition we were able to follow the formation of the macrogel by monitoring the shear viscosity.

  18. Synthesis and characterization of boron nitrides nanotubes

    Ferreira, T.H.; Sousa, E.M.B.

    2010-01-01

    This paper presents a new synthesis for the production of boron nitride nanotubes (BNNT) from boron powder, ammonium nitrate and hematite tube furnace CVD method. The samples were subjected to some characterization techniques as infrared spectroscopy, thermal analysis, X-ray diffraction and scanning electron microscopy and transmission. By analyzing the results can explain the chemical reactions involved in the process and confirm the formation of BNNT with several layers and about 30 nanometers in diameter. Due to excellent mechanical properties and its chemical and thermal stability this material is promising for various applications. However, BNNT has received much less attention than carbon nanotubes, it is because of great difficulty to synthesize appreciable quantities from the techniques currently known, and this is one of the main reasons this work.(author)

  19. Synthesis and processing of composites by reactive metal penetration

    Loehman, R.E.; Ewsuk, K.G. [Sandia National Labs., Albuquerque, NM (United States); Tomsia, A.P. [Pask Research and Engineering, Berkeley, CA (United States)] [and others

    1997-04-01

    Achieving better performance in commercial products and processes often is dependent on availability of new and improved materials. Ceramic-metal composites have advantages over more conventional materials because of their high stiffness-to-weight ratios, good fracture toughness, and because their electrical and thermal properties can be varied through control of their compositions and microstructures. However, ceramic composites will be more widely used only when their costs are competitive with other materials and when designers have more confidence in their reliability. Over the past four years reactive metal penetration has been shown to be a promising technique for making ceramic and metal-matrix composites to near-net-shape with control of both composition and microstructure. It appears that, with sufficient development, reactive metal penetration could be an economical process for manufacturing many of the advanced ceramic composites that are needed for light-weight structural and wear applications for transportation and energy conversion devices. Near-net-shape fabrication of parts is a significant advantage because costly and energy intensive grinding and machining operations are substantially reduced, and the waste generated from such finishing operations is minimized. The most promising compositions to date consist of Al and Al{sub 2}O{sub 3}; thus, these composites should be of particular interest to the aluminum industry. The goals of this ceramic-metal composite research and development program are: (1) to identify compositions favorable for making composites by reactive metal penetration; (2) to understand the mechanism(s) by which these composites are formed; (3) to control and optimize the process so that composites and composite coatings can be made economically; and (4) to apply R&D results to problems of interest to the aluminum industry.

  20. Synthesis and reactivity of uranium (III) cyclopentadienyl complexes

    Foyentin, M.

    1987-01-01

    New uranium organometallic complexes are synthetized from the addition compound Cp U (THF). Reactions with lithium compounds, chlorides, alkynes and borohydrides. Oxidizing addition reactions are evidenced with alkyl halogenides. With a strong reducing agent, the complex Cp-UCH-Li allows the fixation and the reduction of nitrogen into ammonia. Lability of ligands bound to U (III) is evidenced, giving very reactive species and hence catalytic properties for these compounds. Catalytic hydrogenation of olefins is studied. Substitution reactions of alkyl groups of these complexes with olefins in presence or not of hydrogen or with alkyllithium are original [fr

  1. Synthesis of Aluminum Triacrylate as Reactive Filler in EPDM Reinforcement

    Akram Shokrzadeh

    2013-01-01

    Full Text Available The organo-metal salt of aluminum triacrylate (ALTA with a general formula of (CH2=CHCOO3Al was  synthesized  as  a  reactive  fller  for  elastomers through a two-step synthetic procedure. Fourier transform-infrared spectroscopy (FTIR, DSC and DTA were employed for ALTA analysis and to study its cure characteristics. In this research, two composites based on ethylene propylene diene monomer rubber (EPDM with two types of reactive fllers of  modifed organoclay and ALTA were prepared by a laboratory two-roll mill. The types and different ratios of organoclay and ALTA on curing characteristics, mechanical properties such as tensile properties, hardness, and abrasion resistance were studied. The increase in fller content of both composites  led  to  the  incremental  increase  in  tensile strength, modulus, hardness, elongation-at-break and also the incremental increase in abrasion resistance of both composites. The improvement in reinforcing properties of ALTA in comparison with nanoclay is attributed to homopolymerization and graft copolymerization of ALTA at the same time during curing of the EPDM composites by peroxide. Making such additives may be taken as an effective action to achieve more durable and cheaper way to reinforce elastomers.

  2. Synthesis and characterization of dental composites

    Djustiana, Nina; Greviana, Nadia; Faza, Yanwar; Sunarso

    2018-02-01

    During the last few decades, the increasing demands in esthetic dentistry have led to the development of dental composites material that provide similar appearance to the natural teeth. Recently, esthetic trend was an issue which increase the demand for teeth restorations that is similar with the origin. The esthetics of dental composite are more superior compared to amalgam, since its color look similar with natural teeth. Various dental composites have been developed using many type of fillers such as amorphous silica, quartz), borosilicate, Li-Sr-Ba-Al glass and oxide: zirconia and alumina. Researchers in Faculty of Dentistry University of Padjadjaran have prepared dental composites using zirconia-alumina-silica (ZAS) system as the filler. The aim is to improve the mechanical properties and the esthetic of the dental composites. The ZAS was obtained from chemical grade purity chemicals and Indonesia's natural sand as precursors its characterization were also presented. This novel method covers the procedure to synthesis and characterize dental composites in Padjadjaran University and some review about dental composites in global research.

  3. Synthesis and characterization of fluorine compounds

    Martinez Carrillo, M.

    1991-01-01

    The ( 18 F) D-glucose, 2-deoxy fluorine ( 18 FDG) is a radio pharmaceutic that is used in nuclear medicine it is utilized mainly in the glucose metabolism. It allows recently to observe the tumors accumulation and growing. The obtention of this radio pharmaceutic can realize by a nucleophilic or electrophilic process through the use of different fluorinated agents obtained as intermediates for introducing the 18 F radionuclide in a final step of synthesis. The first methods already has been studied in the National Institute of Nuclear Research. The second one which is based this work and it was realized through the reaction of acetyl hypo fluorite (CH 3 COOF) with tri acetyl glucal (TAG) in turn they require the obtention of several fluorated compounds that they serve as intermediates for their obtention so that objective of this work was to find the adequate technique for the obtention of anhydride hydrofluoric acid (HF), KF.2 HF and elemental fluorine so as the design and construction of the systems and equipment used for carry out each one of the reactions. Moreover it was designed the system that will be used for the obtention of acetyl hypo fluoride and the synthesis of composite tetraacetilide 3,4,6 tri-D-glucopyranosil fluoride (TAG-F) for that finally by hydrolysis it was obtained the 2-deoxy fluoride-D-glucose (TAG) in inactive. In this system were realized several preliminary tests. The results are showed in the content of this work also the techniques for compounds characterization were given. (Author)

  4. Synthesis and Characterization of Nano Scale YBCO

    Sukirman, E.; Wisnu AA; Yustinus P; Sahidin W, D.; Rina M, Th.

    2009-01-01

    Synthesis and characterization of the nano scale YBCO superconductor have been performed. The nano scale superconductor was synthesized from YBCO system (YBa 2 Cu 3 O 7-X ). Raw materials, namely Y 2 O 3 , BaCO 3 , and Cu°, were balanced and mixed with ethanol using magnetic steering as a churn in a beaker glass. Then, the precursor was calcined at T k = 900°C for 5 hours and repeated it until three times. The resulting precursor was ground by using High Energy Milling (HEM) for t = 0, 30, 50, 70, and 90 hour and hereinafter precursors are successively referred as YKM-00, YKM-30, YKM-50, YKM-70, and YKM-90. The resulting powders phase were characterized by means of x-ray diffraction technique using the Rietveld analysis method. Precursor of YKM-90 was pressed into pellets, and then sintered at various temperatures and periods. The sample phase was then characterized by using the Rietveld analysis method based on the x-ray diffraction data. The crystallites size were calculated using Scherrer formula. Results of analysis indicate that by minimizing crystallites size, period of sinter can be shortened from 10 to 1 hour, resulting crystallite size of D = 925 Å, critical current density of J c = 4 A / cm 2 , and can be grown of about 15 weight % of 211-phase in a matrix of 123-phase. The decrease of crystallite size will generate a change in physical properties dramatically, if the crystallite size of the material, D is smaller or equal to the coherence length of 10 Å. (author)

  5. Synthesis and reactivity of dimolybdathiaborane cluster [(Cp Mo ...

    Cluster 2 has a bicapped octahedral geometry with the {Fe(CO)3} fragment occupying one of the ... thesis and characterization of [(Cp. ∗ ... Infrared spectra were obtained on a Nicolet 6700 FT-. IR spectrometer. Microanalyses for C, H, and N were performed on .... tains signals attributable to the one type of Cp. ∗ ligand.

  6. THE SYNTHESIS AND THE REACTIVITY OF ARENE RUTHENIUM ...

    a

    [RuCl(η6-p-cymene)(η2-dppm)][PF6] ruthenium complexes with C2O4(Me4N)2 in the ... the Service de Microanalyse du CNRS (Vernaison/France). .... Once bonded to the Ru(II), the characterization of the oxalato ligand by infrared .... The 1H NMR spectrum shows signals of the aromatic proton resonances at 5.45 and 5.15,.

  7. Synthesis, characterization, and reactivity of nickel hydride complexes containing 2,6-C6H3(CH2PR2)2 (R = tBu, cHex, and iPr) pincer ligands.

    Boro, Brian J; Duesler, Eileen N; Goldberg, Karen I; Kemp, Richard A

    2009-06-15

    The syntheses and full characterization of nickel hydrides containing the PCP "pincer"-type ligand, where PCP = 2,6-C(6)H(3)(CH(2)PR(2))(2) (R = tBu, cHex, and iPr), are reported. These Ni-H complexes are prepared by the conversion of ((R)PCP)NiCl precursors into the corresponding nickel hydrides by use of appropriate hydride donors. Surprisingly, although the ((R)PCP)NiCl precursors are quite similar chemically, the conversions to the hydrides were not straightforward and required different hydride reagents to provide analytically pure products. While NaBH(4) was effective in the preparation of pure ((tBu)PCP)NiH, Super-Hydride solution (LiEt(3)BH in THF) was required to prepare either ((cHex)PCP)NiH or ((iPr)PCP)NiH. Attempts to prepare a Ni-H from ((Ph)PCP)NiCl with a variety of hydride reagents yielded only the free ligand as an identifiable product. Two of the derivatives, tBu and cHex, have also been subjected to single crystal X-ray analysis. The solid-state structures each showed a classic, near-square planar arrangement for Ni in which the PCP ligand occupied three meridional ligand points with the Ni-H trans to the Ni-C bond. The resulting Ni-H bond lengths were 1.42(3) and 1.55(2) A for the tBu and cHex derivatives, respectively.

  8. Reactive carbon-chain molecules: synthesis of 1-diazo-2,4-pentadiyne and spectroscopic characterization of triplet pentadiynylidene (H-C[triple bond]C-:C-C[triple bond]C-H).

    Bowling, Nathan P; Halter, Robert J; Hodges, Jonathan A; Seburg, Randal A; Thomas, Phillip S; Simmons, Christopher S; Stanton, John F; McMahon, Robert J

    2006-03-15

    1-Diazo-2,4-pentadiyne (6a), along with both monodeuterio isotopomers 6b and 6c, has been synthesized via a route that proceeds through diacetylene, 2,4-pentadiynal, and 2,4-pentadiynal tosylhydrazone. Photolysis of diazo compounds 6a-c (lambda > 444 nm; Ar or N2, 10 K) generates triplet carbenes HC5H (1) and HC5D (1-d), which have been characterized by IR, EPR, and UV/vis spectroscopy. Although many resonance structures contribute to the resonance hybrid for this highly unsaturated carbon-chain molecule, experiment and theory reveal that the structure is best depicted in terms of the dominant resonance contributor of penta-1,4-diyn-3-ylidene (diethynylcarbene, H-C[triple bond]C-:C-C[triple bond]C-H). Theory predicts an axially symmetric (D(infinity h)) structure and a triplet electronic ground state for 1 (CCSD(T)/ANO). Experimental IR frequencies and isotope shifts are in good agreement with computed values. The triplet EPR spectrum of 1 (absolute value(D/hc) = 0.6157 cm(-1), absolute value(E/hc) = 0.0006 cm(-1)) is consistent with an axially symmetric structure, and the Curie law behavior confirms that the triplet state is the ground state. The electronic absorption spectrum of 1 exhibits a weak transition near 400 nm with extensive vibronic coupling. Chemical trapping of triplet HC5H (1) in an O2-doped matrix affords the carbonyl oxide 16 derived exclusively from attack at the central carbon.

  9. Modeling the Syn-Disposition of Nitrogen Donors in Non-Heme Diiron Enzymes. Synthesis, Characterization, and Hydrogen Peroxide Reactivity of Diiron(III) Complexes with the Syn N-Donor Ligand H2BPG2DEV

    Friedle, Simone; Kodanko, Jeremy J.; Morys, Anna J.; Hayashi, Takahiro; Moënne-Loccoz, Pierre; Lippard, Stephen J.

    2009-01-01

    In order to model the syn disposition of histidine residues in carboxylate-bridged non-heme diiron enzymes, we prepared a new dinucleating ligand, H2BPG2DEV, that provides this geometric feature. The ligand incorporates biologically relevant carboxylate functionalities, which have not been explored as extensively as nitrogen-only analogs. Three novel oxo-bridged diiron(III) complexes [Fe2(μ-O)(H2O)2-(BPG2DEV)](ClO4)2 (6), [Fe2(μ-O)(μ-O CAriPrO)(BPG2DEV)](ClO4) (7), and [Fe2(μ-O)(μ-CO3)(BPG2DEV)] (8) were prepared. Single crystal X-ray structural characterization confirms that two pyridines are bound syn with respect to the Fe–Fe vector in these compounds. The carbonato-bridged complex 8 forms quantitatively from 6 in a rapid reaction with gaseous CO2 in organic solvents. A common maroon-colored intermediate (λmax = 490 nm; ε = 1500 M−1 cm−1) forms in reactions of 6, 7, or 8 with H2O2 and NEt3 in CH3CN/H2O solutions. Mass spectrometric analyses of this species, formed using 18O-labeled H2O2, indicate the presence of a peroxide ligand bound to the oxo-bridged diiron(III) center. The Mössbauer spectrum at 90 K of the EPR-silent intermediate exhibits a quadrupole doublet with δ. = 0.58 mm/s and ΔEQ = 0.58 mm/s. The isomer shift is typical for a peroxodiiron(III) species, but the quadrupole splitting parameter is unusually small compared to related complexes. These Mössbauer parameters are comparable to those observed for a peroxo intermediate formed in the reaction of reduced toluene/o-xylene monooxygenase hydroxylase (ToMOH) with dioxygen. Resonance Raman studies reveal an unusually low-energy O–O stretching mode in the peroxo intermediate that is consistent with a short diiron distance. Although peroxodiiron(III) intermediates generated from 6, 7, and 8 are poor O-atom transfer catalysts, they display highly efficient catalase activity, with turnover numbers up to 10,000. In contrast to hydrogen peroxide reactions of diiron(III) complexes that lack

  10. Polypyrrole-silver Nanocomposite: Synthesis and Characterization

    D. M. Nerkar

    2016-07-01

    Full Text Available Polypyrrole-Silver (PPy-Ag nanocomposite has been successfully synthesized by the chemical oxidative polymerization of pyrrole with iron (III chloride as an oxidant, in the presence of a colloidal suspension of silver nanoparticles. Turkevich method (Citrate reduction method was used for the synthesis of silver nanoparticles (Ag NPs. The silver nanoparticles were characterized by UV-Visible spectroscopy which showed an absorption band at 423 nm confirming the formation of nanoparticles. PPy-Ag nanocomposite was characterized by Transmission Electron Microscopy (TEM, Scanning Electron Microscopy (SEM, Fourier Transform Infrared Spectroscopy (FTIR and X-ray diffraction (XRD techniques for morphological and structural confirmations. TEM and SEM images revealed that the silver nanoparticles were well dispersed in the PPy matrix. XRD pattern showed that PPy is amorphous but the presence of the peaks at 2q values of 38.24°, 44.57°, 64.51° and 78.45° corresponding to a cubic phase of silver, revealed the incorporation of silver nanoparticles in the PPy matrix. A possible formation mechanism of PPy-Ag nanocomposite was also proposed. The electrical conductivity of PPy-Ag nanocomposite was studied using two probe method. The electrical conductivity of the PPy-Ag nanocomposite prepared was found to be 4.657´10- 2 S/cm, whereas that of pure PPy was found to be 9.85´10-3 S/cm at room temperature (303 K. The value of activation energy (Ea for pure PPy was 0.045 eV while it decreased to 0.034 eV for PPy-Ag nanocomposite. The synthesized nanocomposite powder can be utilized as a potential material for fabrication of gas sensors operating at room temperature.

  11. Synthesis and characterization of functional magnetic nanocomposites

    Gass, J.; Sanders, J.; Srinath, S.; Srikanth, H.

    2006-03-01

    Magnetic nanoparticles and carbon nanotubes have been excellent functional materials that could be dispersed in polymer matrices for various applications. However, uniform dispersion of particles in polymers without agglomeration is quite challenging. We have fabricated PMMA/polypyrrole bilayer structures embedded with Fe3O4 magnetite nanoparticles synthesized using wet chemical synthesis. Agglomeration-free dispersion of nanoparticles was achieved by coating the particles with surfactants and by dissolving both the particles and PMMA in chlorobenzene. Structural characterization was done using XRD and TEM. Magnetic properties of the bilayer structures indicated superparamagnetic behavior that is desirable for RF applications as the magnetic losses are reduced. Our polymer nanocomposite bilayer films with conducting polymer coatings are potential candidates for tunable RF applications with integrated EMI suppression. We will also report on our studies of pumped ferrofluids flowing past carbon nanotubes that are arranged in microchannel arrays. Magnetization under various flow conditions is investigated and correlated with the hydrodynamic properties. This scheme provides a novel method of energy conversion and storage using nanocomposite materials.

  12. Magnetic ionic liquids: synthesis and characterization

    Medeiros, Anderson M.M.S.; Parize, Alexandre L.; Oliveira, Vanda M.; Neto, Brenno A.D.; Rubim, Joel C.

    2010-01-01

    The synthesis of magnetic ionic liquids (MILs) based on the stable dispersions of magnetic nanoparticles (MNPs) of γ-Fe 2 O 3 , Fe 3 O 4 , and CoFe 2 O 4 in the ionic liquid 1-n-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (BMI.NTf 2 ) is reported. The MNPs were obtained by the coprecipitation method. The surface of the α-Fe 2 O 3 , Fe 3 O 4 , and CoFe 2 O 4 MNPs with mean sizes (XRD) of 9.3, 12.3, and 11.0 nm, respectively were functionalized by 1-n-butyl-3-(3'-trimethoxypropylsilane)- imidazolium chloride. The non functionalized and functionalized MNPs were further characterized by Raman, FTIR-ATR, and FTNIR spectroscopy and by TGA. The stability of the MILs was assigned to the formation of at least one monolayer of the surface modifier agent that mimics the structure of the BMI.NTf 2 IL. (author)

  13. Synthesis and Characterization of Processable Polyaniline Salts

    Gul, Salma; Bilal, Salma; Shah, Anwar-ul-Haq Ali

    2013-01-01

    Polyaniline (PANI) is one of the most promising candidates for possible technological applications. PANI has potential applications in batteries, anion exchanger, tissue engineering, inhibition of steel corrosion, fuel cell, sensors and so on. However, its insolubility in common organic solvents limits its range of applications. In the present study an attempt has been made to synthesize soluble polyaniline salt via inverse polymerization pathway using benzoyl peroxide as oxidant and dodecylbenzenesulfonic acid (DBSA) as dopant as well as a surfactant. A mixture of chloroform and 2-butanol was used as dispersion medium for the first time. The influence of synthesis parameters such as concentration of aniline, benzoyl peroxide and DBSA on the yield and other properties of the resulting PANI salt was studied. The synthesized PANI salt was found to be completely soluble in DMSO, DMF, chloroform and in a mixture of toluene and 2-propanol. The synthesized polymer salt was also characterized with cyclic voltam-metry, SEM, XRD, UV-Vis spectroscopy and viscosity measurements. TGA was used to analyze the thermal properties of synthesized polymer. The extent of doping of the PANI salt was determined from UV-Vis spectra and TGA analysis. The activation energy for the degradation of the polymer was calculated with the help of TGA.

  14. Synthesis and characterization of novel nanothermometers

    Baumert, Delphine [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Larsen, George [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Coopersmith, Kaitlin [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Schyck, Sarah [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Murph, Simona [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-03-23

    A straightforward approach was developed for the synthesis of Pd, Pd-Fe2O3, Au-Fe2O3, and Au-Pd-Fe2O3 nanothermometers, using a single SL DNA. These NP-DNA conjugates were characterized using techniques including EDX measurements, ζ-potential of NPs before and after DNA functionalization, electron microscopy studies and fluorescence spectroscopy. The fluorescence studies of the NP-DNA demonstrate the interaction between the NP and the fluorophore, which is quenched in the case of Au-Pd-Fe2O3 NPs and is perhaps enhanced (when compared to AuNPs) in the case of Pd and Pd-Fe2O3 NPs. In order to achieve more accurate and reproducible measurements, designing a system that is able to hold the NP-DNA conjugates at a temperature for a longer period of time to allow them to 12 equilibrate is currently underway. Our studies show that Au-Pd-Fe2O3 NPs are the best candidate material to serve as nanothermometers when compared to Pd, Pd-Fe2O3, and Au-Fe2O3 materials.

  15. Synthesis and characterization of six-membered pincer ...

    0013167

    SUPPORTING INFORMATION. REGULAR ARTICLE. Synthesis and characterization of six-membered pincer nickelacycles and application in alkylation of benzothiazole. †. HANUMANPRASAD PANDIRI,a DIPESH M SHARMA,a RAJESH G GONNADEb and. BENUDHAR PUNJI*,a. aOrganometallic Synthesis and Catalysis ...

  16. Synthesis and characterization of tantalum organometallic complexes. Catalytic activity for olefins

    Baley, A.S.

    1990-11-01

    Synthesis of monoaryloxy (alcoxy) neopentyl compounds is investigated. The tantalum-oxygen bond is formed by two parallel ways from TaCl 5 or TaR 2 Cl 3 with R = neopentyl and the tantalum carbon bond from a neopentyl derivative of the main series. Some compounds were isolated and characterized by NMR, elemental analysis and sometimes X-ray structure, some others are characterized in solution only. Catalytic effect is tested by ethylene dimerization and olefin polymerization. Reactivity of tantalum aryloxy neopentyl in respect to complexing and chelating ligands is studied for preparation of neopentylidene complexes

  17. Green synthesis, characterization and antibacterial activity of copper ...

    Green synthesis, characterization and antibacterial activity of copper nanoparticles using L -ascorbic ... Journal Home > Vol 10, No 3 (2017) > ... In this study, simple, economical, convenient and environmentally-friendly chemical reduction ...

  18. Synthesis and characterization of amorphous cellulose from triacetate of cellulose

    Vega-Baudrit, Jose; Sibaja, Maria; Nikolaeva, Svetlana; Rivera A, Andrea

    2014-01-01

    It was carried-out a study for the synthesis and characterization of amorphous cellulose starting from cellulose triacetate. X-rays diffraction was used in order to obtain the cellulose crystallinity degree, also infrared spectroscopy FTIR was used. (author)

  19. Combustion synthesis and structural characterization of Li–Ti mixed

    Combustion synthesis and structural characterization of Li–Ti mixed nanoferrites ... were prepared by combustion method at lower temperatures compared to the ... first time at low temperatures, using PEG which acts as a new fuel and oxidant.

  20. Synthesis and characterization of new optically active poly(amide ...

    Synthesis and characterization of new optically active poly(amide-imide)s based on N -trimellitimido- ... Bulletin of the Chemical Society of Ethiopia ... (DMAc), dimethyl sulfoxide (DMSO) and N-methyl-2-pyrrolidone (NMP) at room temperature.

  1. Novel Green Synthesis and Characterization of Nanopolymer ...

    Purpose: To develop a novel approach to green synthesis of nano-polymer porous gold oxide nanoparticles, and examine the effects of the temperatures on their surface. Methods: Green synthesis of nano-polymer porous gold oxide nanoparticles (GONPs) using cetyle trimethylammonium bromide (CTAB) surfactant with a ...

  2. Synthesis, characterization and applications of graphene architectures

    Thomas, Abhay Varghese

    Graphene, a two--dimensional sheet of sp2 hybridized carbon atoms arranged in a honeycomb lattice structure, has garnered tremendous interest from the scientific community for its unique combination of properties. It has interesting electrical, thermal, optical and mechanical properties that scientists and engineers are trying to understand and harness to improve current products as well as focus on disruptive technologies that can be made possible by this next generation material. In this thesis the synthesis, characterization and applications of various graphene architectures were explored from the context of a bottom--up and top--down synthesis approach. The work is divided into three main chapters and each one deals with a unique architecture of graphene as well as its properties and an application to a real world problem. In Chapter 2, we focus on bottom--up synthesis of graphene sheets by chemical vapor deposition. We then studied the wetting properties of graphene coated surfaces. More specifically the wetting properties of single and multilayer graphene films on flat and nanoscale rough surfaces are explored and the insights gained are used in improving heat transfer performance of copper surfaces. Single layer graphene, on certain flat surfaces, was shown to exhibit `wetting transparency' as a result of its sheer thinness and this property is of interest in various wetting related applications. Surface protection from corrosion and/or oxidation without change in wetting properties is tremendously useful in multiple fields and we looked to apply this property to dehumidification of copper surfaces. The short time scales results demonstrated that graphene indeed served to prevent oxidation of the surface which in turn promoted increased heat transfer co--efficients with respect to the oxidized copper surfaces. Closer inspection of the surface over long time scales however revealed that the oxide layer changed the wetting properties and this was detrimental

  3. Novel metallomesogenic polyurethanes: Synthesis, characterization and properties

    Senthilkumar, Natarajan; Narasimhaswamy, Tanneru; Kim, Il-Jin

    2012-01-01

    A series of tetradentate Schiff base metallomesogenic diols were synthesized from two simple dihydroxy benzenes. The metallomesogenic diol was constructed from three ring containing mesogen linked through ester and azomethine with terminal hydroxy group. This upon complexation with copper(II) formed metallomesogenic diol with varying terminal chain length. A series of metallomesogenic polyurethanes were synthesized using these metallomesogenic diols as chain extenders for the prepolymers based on polytetramethylene glycol (PTMG) of varying molecular weight (M n = 650, 2000) and 2,4-toluene diisocyanate (TDI), or 4,4′-methylene bis(phenyl isocyanate) (MDI). The molar ratio of metallomesogenic diol and PTMG were varied in the polyurethane to find their role in liquid crystalline and mechanical properties. Extensive characterization of all metallomesogenic compounds and intermediates were carried out by FT-IR, 1 H and 13 C NMR, EPR, VSM, Mass (EI and FAB) and UV–visible spectroscopy. Hot stage polarizing microscope and differential scanning calorimetry were used to ensure the phase characteristics such as nature of phase, melting and clearing temperatures and phase range. The appearance of enantiotropic smectic A phases indicated high molecular polarizability of the core due to the metal ion. - Highlights: ► Design and synthesis of metallomesogenic diols. ► Metallomesogenic polyurethanes were prepared using these diols as chain extenders. ► Liquid crystalline and mechanical properties were studied. ► A square pyramidal structure for the copper(II) complexes have been proposed. ► Polyurethanes exhibited enantiotropic smectic A phases.

  4. Synthesis and characterization of europium aluminophosphate

    Araujo, A.S.; Diniz, J.C.; Silva, A.O.S.

    1998-01-01

    Full text: Aluminophosphate molecular sieves (ALPO) represents a class of materials formed by AlO 2+ and PO 2- tetrahedra linked together through b the oxygen atom. The incorporation of metal cations, specifically rare earths, in the ALPO matrix, gives rise to generation of new materials that can be used as acid catalysts in chemical processes. In this work, it was synthesized hydrothermally a molecular sieve type Eu-ALPO-11, starting from an hydrated alumina (pseudobohemite), phosphoric acid solution, europium chloride, water, and di-isopropylamine (DIPA) as organic template. The gel of synthesis presented the following composition: 1.0 DIPA: 0.05 Eu 2 O 3 :0.95 Al 2 O 3 : 1.0 P 2 O 5 : 80 H 2 O The hydrogel was autoclaved at 170 deg C for a period of 3 days. After that the obtained solid was filtered, washed, dried and calcined at 500 deg C to remove the template. The sample was characterized by several physico-chemical methods, such a atomic absorption, FT-IR spectroscopy, X-ray diffraction, thermal analysis, scanning electron microscopy. Its spectroscopic properties was investigated by europium luminescence. The physico-chemical characterization of the Eu-ALPO-11 showed very good crystallinity, with AEL structure, and orthorhombic symmetry. Also, the material presents excellent thermal stability, with no structural collapse until 950 deg C. Through the luminescence spectra in the visible region, it was observed that the emission of the Eu 3+ is strongly influenced by the increasing of the 5d0 7f0 transition (Electric Dipole), as compared to the 5d0 7f1 transition (Magnetic Dipole) between the levels of 4f configuration perturbed by the crystalline field. The ED/MD ratio to the as synthesized sample was ca. 2.1, against ca. 1.1 relative to the calcined sample. The FT-IR spectra presented well defined absorption bands relative to Al-O and P-O bonds, of the structural internal tetrahedra (IT) and external links (EL): 1250- 950 cm -1 , symmetric stretching due to

  5. Synthesis and characterization of fluorophore attached silver ...

    Administrator

    in protein detection (Nam et al 2003), labeling agents. (Tkachenko et al ... these chemicals are highly reactive and pose potential environmental and ... The interaction of rhodamine 6G with ... lar excretion of the kidney although the electrostatic.

  6. Novel Green Synthesis and Characterization of Nanopolymer ...

    Purpose: To develop a novel approach to green synthesis of nano-polymer porous gold ... underline their important uses in various fields ... enhances physical and chemical characteristics .... Nanoporous Materials: Science and Engineering.

  7. Synthesis, Characterization and Application of Nano Lepidocrocite ...

    NICO

    Degradation of halogenated organic compounds using nanoparticles is one of the innovative ... way as the synthesis of nano zero-valent iron by using sodium .... +. −. 2и High. 2и Low. FWHM. Crystallite. /counts. /counts. /degree. /degree.

  8. Characterizing Nanoparticles Reactivity: Structure-Photocatalytic Activity Relationship

    Piella, J; Bastús, N G; Casals, E; Puntes, V

    2013-01-01

    Nanoparticles are reactive, and their final interactions with the surrounding media are ultimately determined by their reactivity, which in turns depends on the nanoparticles morphology, surface chemistry and environment in which they are embedded. One simple and informative approach for the study of the reactivity of nanoparticles is the determination of their photocatalytic activity. In the present work, we briefly summarize the importance of different parameters such as the size, shape and agglomeration state on the photocatalytic activity of colloidal inorganic nanoparticles. The study of the use of nanoparticles as photocatalyts is relevant not only for its potential applications in environmental remediation issues but also it can provide relevant information about the role of these parameters at the nanoscale.

  9. Reactive melt infiltration of copper in Al–Cr preforms produced through combustion synthesis

    Naplocha, Krzysztof; Granat, Kazimierz; Kaczmar, Jacek

    2014-01-01

    Highlights: • Determination of microstructure and phase transformation during combustion synthesis and reactive infiltration. • Squeeze casting of Cu inducing reactive infiltration of Al–Cr intermetallic porous preform. • Fabrication of unique composite material resisted to high temperature oxidation. - Abstract: Combustion synthesis of Al–Cr preforms used for infiltration and reinforcing of composite materials was developed. Compacts of powdered Al and Cr with stoichiometric ratio Al/Cr equal to 2/1 were synthesized in a microwave reactor furnished with a pyrometer for controlling phase transformations. Due to low enthalpy of the reaction, green compacts were preheated and ignition occurred together with partial melting of Al at the interface with Cr particles. The synthesis proceeded by peritectic transformations L + Al 7 Cr → L + Al 11 Cr 2 → L + Al 4 Cr, reaching maximum temperature of ca. 1000 °C. Porous structures including residual unprocessed Cr particles were soaked to homogenize them and to transform the phases into the stable intermetallic compound Al 9 Cr 4 . Reactive infiltration of the preforms with molten Cu proceeds along with interfacial diffusion of Al that, released from a preform, infiltrates into the matrix changing its composition to Cu 9 Al 4 (Cr). At the same time, the preform is decomposed and converted into a mixture of globular precipitates of Cr 52 Al 35 Cu 13 embedded in the Cu 47 Al 41 Cr 12 phase. The produced composite materials exhibit significant hardness and oxidation resistance at elevated temperatures. The protective layer is composed of oxides Al 2 O 3 and (AlCu) 2 O 3 created at parabolic constant oxidation rate (k p ) equal to 1.9 × 10 −6 g 2 m −4 s −1

  10. Synthesis and Properties of Sulfhydryl-Reactive Near-Infrared Cyanine Fluorochromes for Fluorescence Imaging

    Yuhui Lin

    2003-04-01

    Full Text Available Near-infrared fluorochromes (NIRF are useful compounds for diverse biotechnology applications and for in vivo biomedical imaging. Such NIRF must have high quantum yield, be biocompatible, and be conjugatable to a wide variety of proteins, peptides, and other affinity ligands. Here, we describe the synthesis of four new nonsymmetrical sulfhydryl-reactive cyanine NIRF with excellent optical and chemical properties. Each fluorochrome was designed to contain an iodoacetamido group that reacts specifically with sulfhydryl-containing molecules. The synthesized fluorochromes were used to label model peptides and sulfhydryl-containing biomolecules.

  11. Synthesis of organolanthanides by metal addition on insaturated substrates in ether and reactivity

    Olivier, H.

    1988-01-01

    The aim of the study is the extension to rare earths of the synthesis, well known for alkaline or alkaline earth metals, by direct metal addition to insaturated substrates in ether and where the metal is directly bound to carbon. A definition of formation conditions and affinity rules is attempled, both with substrates (essentially aromatic hydrocarbons and ketones) and with metals: Yb, Sm, Ce, Nd and others. The nature of obtained products by reaction of electrophiles on synthetised organometallics, allows investigations specific reactivity and structure. Potential catalytic transformation of olefins is precised [fr

  12. Synthesis, spectral characterization and in vitro antibacterial ...

    Shafqat Nadeem

    2015-12-17

    Dec 17, 2015 ... slightly toxic and present a potential for antibacterial activity. Moreover, they ... interaction, in this paper, we describe the coordination of Pal- ladium(II) iodide with .... between steric/electrostatic property and biological activity. Table. 1 ..... properties, affinity to proteins, reactivity, toxicity, metabolic stability and ...

  13. Colloidal phytosterols: synthesis, characterization and bioaccessibility

    Rossi, L.; Seijen ten Hoorn, J.W.M.; Melnikov, S.M.; Velikov, K.P.

    2010-01-01

    We demonstrate the synthesis of phytosterol colloidal particles using a simple food grade method based on antisolvent precipitation in the presence of a non-ionic surfactant. The resulting colloidal particles have a rod-like shape with some degree of crystallinity. The colloidal dispersions display

  14. Synthesis and Characterization of Furanic Compounds

    2013-09-01

    Furanamine. Solvent 2-Furanamine Acetone — Chloroform — Dimethylacetamide (DMAc) — Dimethylsulfoxide ( DMSO ) + Methanol ± Tetrahydrofuran (THF...4 Figure 4. 1 H NMR of 2-Furanamine in D2O solvent ...Spectra for the furanic compounds were obtained in a 0.1%–0.5% deuterated solvent solutions. 3. Synthesis 3.1 General The following monomers and

  15. Synthesis, Characterization and Antimicrobial Activities of Some ...

    user

    of metal ions with vitamin.111: Synthesis and infrared spectra of metal complexes with pyridoxamine and pyridoxine. Inorg. Chim. Acta, 46, 191-197. Gary, J and Adeyemo, A (1981) Interaction of vitamin B1 with Zn(II), Cd (II) and Hg(II) in. Deuterated Dimethyl Sulfoxide. Inorg. Chim. Acta, 55, 93-98. Gohzalez-vergara, E ...

  16. Synthesis, characterization and photochemistry of a new ...

    The synthesis, crystal structure, redox characteristics and photochemistry of a new heptamolyb- ... The ability of [Mo7O24]−6 to function as a pure “inor- .... Abbreviations used: bpp = 1,3-bis(4-pyridyl)propane; 2-amp = 2-aminopyridine; DMSO ...

  17. Biological synthesis and characterization of silver nanoparticles ...

    or less have engrossed great attention due to their unusual and captivating ... ical method of nanoparticles synthesis using microorgan- isms, enzyme and plant or plant .... mined using Student's t-test with two-way Anova was set at p ≤ 0.05. 3.

  18. Synthesis and characterization of saturated polyester and ...

    but which can actually be used for processes, which pro- duce interesting ... ing the synthesis of saturated polyester (from GPET waste). This has been done for the .... The solid product obtained from the glycolysis of PET was bis(hydroxy ethyl ...

  19. Biological synthesis and characterization of intracellular gold ...

    In the present study, Aspergillus fumigatus was used for the intracellular synthesis of gold nanoparticles. Stable nanoparticles were produced when an aqueous solution of chloroauric acid (HAuCl4) was reduced by A. fumigatus biomass as the reducing agent. Production of nanoparticles was confirmed by the colour ...

  20. Auto-combustion Synthesis, Characterization and Photovoltaic

    NICOLAAS

    Ag-NiTiO3, sol-gel method, semiconductor, photovoltaic, doping. 1. Introduction ... convenient for synthesis of pure mixed metal oxides nanoparticles. Furthermore .... current density voltage (I-V) curve for Ag-NiTiO3 was carried out under the ...

  1. Synthesis of Novel Reactive Disperse Silicon-Containing Dyes and Their Coloring Properties on Silicone Rubbers

    Ning Yu

    2018-01-01

    Full Text Available Novel red and purple reactive disperse silicon-containing dyes were designed and synthesized using p-nitroaniline and 6-bromo-2,4-dinitro-aniline as diazonium components, the first condensation product of cyanuric chloride and 3-(N,N-diethylamino-aniline as coupling component, and 3-aminopropylmethoxydimethylsilane, 3-aminopropylmethyldimethoxysilane, and 3-aminopropyltrimethoxysilane as silicone reactive agents. These dyes were characterized by UV-Vis, 1H-NMR, FT-IR, and MS. The obtained reactive disperse silicon-containing dyes were used to color silicone rubbers and the color fastness of the dyes were evaluated. The dry/wet rubbing and washing fastnesses of these dyes all reached 4–5 grade and the sublimation fastness was also above 4 grade, indicating outstanding performance in terms of color fastness. Such colored silicone rubbers showed bright and rich colors without affecting its static mechanical properties.

  2. Synthesis and characterization of nanocrystalline nuclear ceramics

    Ananthasivan, K.; Anthonysamy, S.; Chandramouli, V.; Vasudeva Rao, P.R.

    2006-01-01

    This paper highlights the utility of the gel-combustion synthesis in making solid solutions containing the oxides of U, Th, and Ce. The synthesis of a series of solid solutions of ceria with thoria and urania using the gel-combustion technique with citric acid as the fuel is presented as a typical case. The x-ray crystallite size, specific surface area, and residual carbon of the precursors and final products are discussed. The sinterability of these powders is analysed using their sintered densities. Solid solutions of thoria-ceria with a density higher than 85% TD (theoretical density) and those of urania ceria with a density as high as 96% TD were obtained. The microstructure of the thoria-ceria powders were analysed using high resolution electron microscopy. (author)

  3. Synthesis and characterization of magnetite nanoparticles coated with lauric acid

    Mamani, J.B., E-mail: javierbm@einstein.br [Instituto do Cérebro-InCe, Hospital Israelita Albert Einstein-HIAE, 05651-901 São Paulo (Brazil); Costa-Filho, A.J. [Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto (Brazil); Cornejo, D.R. [Instituto de Física Universidade de São Paulo, USP, São Paulo (Brazil); Vieira, E.D. [Instituto de Física, Universidade Federal de Goiás, Goiânia (Brazil); Gamarra, L.F. [Instituto do Cérebro-InCe, Hospital Israelita Albert Einstein-HIAE, 05651-901 São Paulo (Brazil)

    2013-07-15

    Understanding the process of synthesis of magnetic nanoparticles is important for its implementation in in vitro and in vivo studies. In this work we report the synthesis of magnetic nanoparticles made from ferrous oxide through coprecipitation chemical process. The nanostructured material was coated with lauric acid and dispersed in aqueous medium containing surfactant that yielded a stable colloidal suspension. The characterization of magnetic nanoparticles with distinct physico-chemical configurations is fundamental for biomedical applications. Therefore magnetic nanoparticles were characterized in terms of their morphology by means of TEM and DLS, which showed a polydispersed set of spherical nanoparticles (average diameter of ca. 9 nm) as a result of the protocol. The structural properties were characterized by using X-ray diffraction (XRD). XRD pattern showed the presence of peaks corresponding to the spinel phase of magnetite (Fe{sub 3}O{sub 4}). The relaxivities r{sub 2} and r{sub 2}* values were determined from the transverse relaxation times T{sub 2} and T{sub 2}* at 3 T. Magnetic characterization was performed using SQUID and FMR, which evidenced the superparamagnetic properties of the nanoparticles. Thermal characterization using DSC showed exothermic events associated with the oxidation of magnetite to maghemite. - Highlights: • Synthesis of magnetic nanoparticles coated with lauric acid • Characterization of magnetic nanoparticles • Morphological, structural, magnetic, calorimetric and relaxometric characterization.

  4. Molybdenum oxide nanocubes: Synthesis and characterizations

    Muthamizh, S.; Suresh, R.; Giribabu, K.; Manigandan, R.; Kumar, S. Praveen; Munusamy, S.; Narayanan, V., E-mail: vnnara@yahoo.co.in [Department of Inorganic Chemistry, University of Madras, Guindy Campus, Chennai -600025 (India); Stephen, A. [Department of Nuclear Physics, University of Madras, Guindy Campus, Chennai-600025 (India)

    2015-06-24

    Molybdenum oxide nanoparticles were prepared by Solid state synthesis. The MoO{sub 3} nanoparticles were synthesized by using commercially available ammonium heptamolybdate. The XRD pattern reveals that the synthesized MoO{sub 3} has orthorhombic structure. In addition, lattice parameter values were also calculated using XRD data. The Raman analysis confirm the presence of Mo-O in MoO{sub 3} nanoparticles. DRS-UV analysis shows that MoO{sub 3} has a band gap of 2.89 eV. FE-SEM analysis confirms the material morphology in cubes with nano scale.

  5. Synthesis and characterization of dextran-coated iron oxide nanoparticles

    Predescu, Andra Mihaela; Matei, Ecaterina; Berbecaru, Andrei Constantin; Pantilimon, Cristian; Drăgan, Claudia; Vidu, Ruxandra; Predescu, Cristian; Kuncser, Victor

    2018-03-01

    Synthesis and characterization of iron oxide nanoparticles coated with a large molar weight dextran for environmental applications are reported. The first experiments involved the synthesis of iron oxide nanoparticles which were coated with dextran at different concentrations. The synthesis was performed by a co-precipitation technique, while the coating of iron oxide nanoparticles was carried out in solution. The obtained nanoparticles were characterized by using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction spectrometry, Fourier transform infrared spectroscopy and superconducting quantum interference device magnetometry. The results demonstrated a successful coating of iron oxide nanoparticles with large molar weight dextran, of which agglomeration tendency depended on the amount of dextran in the coating solution. SEM and TEM observations have shown that the iron oxide nanoparticles are of about 7 nm in size.

  6. Synthesis and reactivity of compounds containing ruthenium-carbon, -nitrogen, and -oxygen bonds

    Hartwig, J.F.

    1990-12-01

    The products and mechanisms of the thermal reactions of several complexes of the general structure (PMe 3 ) 4 Ru(X)(Y) and (DMPM) 2 Ru(X)(Y) where X and Y are hydride, aryl, and benzyl groups, have been investigated. The mechanism of decomposition depends critically on the structure of the complex and the medium in which the thermolysis is carried out. The alkyl hydride complexes are do not react with alkane solvent, but undergo C-H activation processes with aromatic solvents by several different mechanisms. Thermolysis of (PMe 3 ) 4 Ru(Ph)(Me) or (PMe 3 ) 4 Ru(Ph) 2 leads to the ruthenium benzyne complex (PMe 3 ) 4 Ru(η 2 -C 6 H 4 ) (1) by a mechanism which involves reversible dissociation of phosphine. In many ways its chemistry is analogous to that of early rather than late organo transition metal complexes. The synthesis, structure, variable temperature NMR spectroscopy and reactivity of ruthenium complexes containing aryloxide or arylamide ligands are reported. These complexes undergo cleavage of a P-C bond in coordinated trimethylphosphine, insertion of CO and CO 2 and hydrogenolysis. Mechanistic studies on these reactions are described. The generation of a series of reactive ruthenium complexes of the general formula (PMe 3 ) 4 Ru(R)(enolate) is reported. Most of these enolates have been shown to bind to the ruthenium center through the oxygen atom. Two of the enolate complexes 8 and 9 exist in equilibrium between the O- and C-bound forms. The reactions of these compounds are reported, including reactions to form oxygen-containing metallacycles. The structure and reactivity of these ruthenium metallacycles is reported, including their thermal chemistry and reactivity toward protic acids, electrophiles, carbon monoxide, hydrogen and trimethylsilane. 243 refs., 10 tabs

  7. Synthesis and reactivity of compounds containing ruthenium-carbon, -nitrogen, and -oxygen bonds

    Hartwig, J.F.

    1990-12-01

    The products and mechanisms of the thermal reactions of several complexes of the general structure (PMe{sub 3}){sub 4}Ru(X)(Y) and (DMPM){sub 2}Ru(X)(Y) where X and Y are hydride, aryl, and benzyl groups, have been investigated. The mechanism of decomposition depends critically on the structure of the complex and the medium in which the thermolysis is carried out. The alkyl hydride complexes are do not react with alkane solvent, but undergo C-H activation processes with aromatic solvents by several different mechanisms. Thermolysis of (PMe{sub 3}){sub 4}Ru(Ph)(Me) or (PMe{sub 3}){sub 4}Ru(Ph){sub 2} leads to the ruthenium benzyne complex (PMe{sub 3}){sub 4}Ru({eta}{sup 2}-C{sub 6}H{sub 4}) (1) by a mechanism which involves reversible dissociation of phosphine. In many ways its chemistry is analogous to that of early rather than late organo transition metal complexes. The synthesis, structure, variable temperature NMR spectroscopy and reactivity of ruthenium complexes containing aryloxide or arylamide ligands are reported. These complexes undergo cleavage of a P-C bond in coordinated trimethylphosphine, insertion of CO and CO{sub 2} and hydrogenolysis. Mechanistic studies on these reactions are described. The generation of a series of reactive ruthenium complexes of the general formula (PMe{sub 3}){sub 4}Ru(R)(enolate) is reported. Most of these enolates have been shown to bind to the ruthenium center through the oxygen atom. Two of the enolate complexes 8 and 9 exist in equilibrium between the O- and C-bound forms. The reactions of these compounds are reported, including reactions to form oxygen-containing metallacycles. The structure and reactivity of these ruthenium metallacycles is reported, including their thermal chemistry and reactivity toward protic acids, electrophiles, carbon monoxide, hydrogen and trimethylsilane. 243 refs., 10 tabs.

  8. Electrochemical synthesis and spectroscopic characterization of ...

    phenylpyrrole) coatings in an organic medium on iron and platinum electrodes. ... XPS measurements, infrared (FT-IR) and electronic absorption (UV-vis) spectroscopies were used to characterize the iron and platinum-coated electrodes. Finally the ...

  9. Synthesis and characterization of multicolour fluorescent ...

    ... of latent fingerprints. The optical and structural characterization of the nanoparticles was carried .... by absorption of phonons from the host matrix [13], the exchange of energy in ... impressions based on the fluorescent properties exhibited by.

  10. Synthesis, spectroscopic characterization and catalytic oxidation ...

    were characterized by infrared, electronic, electron paramagnetic resonance ... The catalytic oxidation property of ruthenium(III) complexes were also ... cies at room temperature. ..... aldehyde part of Schiff base ligands, catalytic activ- ity of new ...

  11. Synthesis, characterization and photoluminescence properties of ...

    G Prabhavathi

    carbon nanomaterials reported to date contain only unsubstituted ... 2.1 Materials and characterization. Pyrrole ... trum (FTIR) was taken using the KBr pellet method on a Thermo ..... and quantum yield measurement procedure are available at.

  12. Synthesis, characterization and electrochemistry of heterobimetallic ...

    dimethylpyrazolyl) borate with a series of manganese(II) Schiff bases have been synthesized. Characterization by UV, IR, MS and elemental analysis support their formulations. Cyclic and differential pulse voltammograms of manganese(II) Schiff base ...

  13. electrochemical synthesis and spectroscopic characterization of poly ...

    a

    to characterize the iron and platinum-coated electrodes. Finally the ... their derivatives, is easily anodically performed on inert substrates such as platinum, gold, glassy carbon and .... because the electrode is more significantly protected. After 5 ...

  14. Synthesis and characterization of composites of mixed oxides of iron ...

    Home; Journals; Bulletin of Materials Science; Volume 34; Issue 4. Synthesis and characterization of composites of mixed oxides of iron and neodymium in polymer matrix of aniline–formaldehyde. Sajdha H N Sheikh B L Kalsotra N Kumar S Kumar. Volume 34 Issue 4 July 2011 pp 843-851 ...

  15. Synthesis and characterization of cadmium doped lead–borate ...

    Unknown

    Mater. Sci., Vol. 29, No. 1, February 2006, pp. 55–58. © Indian Academy of Sciences. 55. Synthesis and characterization of cadmium doped lead–borate glasses. A A ALEMI*, H SEDGHI†, A R MIRMOHSENI and V GOLSANAMLU. Department of Inorganic Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz, Iran.

  16. Synthesis and characterization of germa[n]pericyclynes.

    Tanimoto, Hiroki; Nagao, Tomohiko; Nishiyama, Yasuhiro; Morimoto, Tsumoru; Iseda, Fumiyasu; Nagato, Yuko; Suzuka, Toshimasa; Tsutsumi, Ken; Kakiuchi, Kiyomi

    2014-06-14

    The synthesis and characterization of novel pericyclynes comprising germanium atoms and acetylenes, germa[n]pericyclynes, are described. The prepared germa[4]-, [6]-, and [8]pericyclynes were compared by (13)C NMR spectroscopy, X-ray crystallography, cyclic voltammetry, UV-visible spectroscopy, fluorescence emission spectroscopy, Raman spectroscopy, and density functional theory calculation analyses.

  17. Synthesis and structural characterization of a calcium coordination ...

    Synthesis and structural characterization of a calcium coordination polymer based on a μ3-bridging. tetradentate binding mode of glycine. SUBRAMANIAN NATARAJAN*a, BIKSHANDARKOIL R. SRINIVASANb , J. KALYANA SUNDARa, K. RAVIKUMARc , R.V. KRISHNAKUMARd , J. SURESHe,. aSchool of Physics, ...

  18. Synthesis & Characterization of New bis-Symmetrical Adipoyl ...

    Full Title: Synthesis and Characterization of New bis-Symmetrical Adipoyl, Terepthaloyl, Chiral Diimido-di-L-alanine Diesters and Chiral Phthaloyl-L-alanine Ester of Tripropoxy p-tert-Butyl Calix[4]arene and Study of Their Hosting Ability for Alanine and Na+. Bis-symmetrical tripropoxy p-tert-butyl calix[4]arene esters were ...

  19. SYNTHESIS AND CHARACTERIZATION OF N, N'-BIS-(3 ...

    user

    base complexes derived from Salicylaldehyde and histidine with some divalent transition metal ions. Furthermore, Syed (1993) reported the synthesis, characterization and biological evaluation of some. Schiff base metal complexes derived from Anthranilic acid-sugar and naturally occurring amino acid-sugar. Schiff bases ...

  20. Synthesis and characterization of thermally oxidized ZnO films

    Administrator

    Synthesis and characterization of thermally oxidized ZnO films. A P RAMBU1,* and N IFTIMIE2 .... R. −. Δ. = = (1) where Ra is the sensor resistance in the air and Rg is the .... ple, Aida and coworkers (2006) reported that the total oxidation is ...

  1. Synthesis of oxidized guar gum by dry method and its application in reactive dye printing.

    Gong, Honghong; Liu, Mingzhu; Zhang, Bing; Cui, Dapeng; Gao, Chunmei; Ni, Boli; Chen, Jiucun

    2011-12-01

    The aim of this study was to prepare oxidized guar gum with a simple dry method, basing on guar gum, hydrogen peroxide and a small amount of solvent. To obtain a product with suitable viscosity for reactive dye printing, the effects of various factors such as the amount of oxidant and solvent, reaction temperature and time were studied with respect to the viscosity of reaction products. The product was characterized by Fourier transform infrared spectroscopy, size exclusion chromatography, scanning electron microscopy and differential scanning calorimetry. The hydrated rate of guar gum and oxidized guar gum was estimated through measuring the required time when their solutions (1%, w/v) reached the maximum viscosity. The effects of the salt concentration and pH on viscosity of the resultant product were studied. The mixed paste containing oxidized guar gum and carboxymethyl starch was prepared and its viscosity was determined by the viscometer. The rheological property of the mixed paste was appraised by the printing viscosity index. In addition, the applied effect of mixed paste in reactive dye printing was examined by assessing the fabric stiffness, color yield and sharp edge to the printed image in comparison with sodium alginate. And the results indicated that the mixed paste could partially replace sodium alginate as thickener in reactive dye printing. The study also showed that the method was low cost and eco-friendly and the product would have an extensive application in reactive dye printing. Copyright © 2011 Elsevier B.V. All rights reserved.

  2. Synthesis and characterization of monodispersed silver nanoparticles

    Jegatha Christy, A.; Umadevi, M.

    2012-09-01

    Synthesis of silver nanoparticles (NPs) has become a fascinating and important field of applied chemical research. In this paper silver NPs were prepared using silver nitrate (AgNO3), gelatin, and cetyl trimethyl ammonium bromide (CTAB). The prepared silver NPs were exposed under the laser ablation. In our photochemical procedure, gelatin acts as a biopolymer and CTAB acts as a reducing agent. The appearance of surface plasmon band around 410 nm indicates the formation of silver NPs. The nature of the prepared silver NPs in the face-centered cubic (fcc) structure are confirmed by the peaks in the x-ray diffraction (XRD) pattern corresponding to (111), (200), (220) and (311) planes. Monodispersed, stable, spherical silver NPs with diameter about 10 nm were obtained and confirmed by high-resolution transmission electron microscope (HRTEM).

  3. Synthesis and characterization of monodispersed silver nanoparticles

    Christy, A Jegatha; Umadevi, M

    2012-01-01

    Synthesis of silver nanoparticles (NPs) has become a fascinating and important field of applied chemical research. In this paper silver NPs were prepared using silver nitrate (AgNO 3 ), gelatin, and cetyl trimethyl ammonium bromide (CTAB). The prepared silver NPs were exposed under the laser ablation. In our photochemical procedure, gelatin acts as a biopolymer and CTAB acts as a reducing agent. The appearance of surface plasmon band around 410 nm indicates the formation of silver NPs. The nature of the prepared silver NPs in the face-centered cubic (fcc) structure are confirmed by the peaks in the x-ray diffraction (XRD) pattern corresponding to (111), (200), (220) and (311) planes. Monodispersed, stable, spherical silver NPs with diameter about 10 nm were obtained and confirmed by high-resolution transmission electron microscope (HRTEM). (paper)

  4. Synthesis, physical characterization, antibacterial activity and ...

    Some five-coordinated cobalt(III) complexes were synthesized and characterized using elemental analysis, 1H NMR and IR spectra. The formation constants and the thermodynamic parameters were measured spectrophotometrically for the 1:1 adduct formation of [Co(Chel)(PBu3)]ClO4.H2O where Chel = cd3OMesalen, ...

  5. Biomimetic synthesis and characterization of semiconducting hybrid

    Triple hybrid materials based on polyaniline-polyethylene glycol and cadmium sulphide have been prepared by the duffusion–limited biomimetic route and characterized by a number of spectroscopic, XRD, SEM, thermal and electrical measurements. These hybrid materials have been prepared by controlled precipitation of ...

  6. Synthesis and characterization of a reduced heteropoly ...

    Compound (1) crystallizes in a cubic space group 3 ¯ , with = 22.2001(6) Å and = 8. The anion [VVO4W 10 VI V 2 IV O36]7- is a typical Keggin type structure with VVO4 as the central tetrahedron. (1) has further been characterized by elemental analyses, redox titration, IR, EPR, and electronic spectroscopy and room ...

  7. Synthesis, characterization and antimicrobial activity of mixed ...

    A new series of Mn(II), Fe(II), Co(II), Cu(II) and Zn(II) mixed ligands-metal complexes derived from salicylic acid (SA) and 1,10-phenanthroline (PHEN) have been synthesized and characterized by spectroscopic studies. The coordination of the two ligands towards central metal ions has been proposed in the light of ...

  8. Synthesis and Characterization of Novel Quaternary Thioaluminogermanates

    Al-Bloushi, Mohammed

    2013-01-01

    compounds of the type “M(AlS2)(GeS2)” (M = Na and K) are new metal-chalcogenides, synthesized by the classical solid state approach. The characterization of these compounds was carried out by Scanning Electron Microscopy (SEM), Energy Dispersive X

  9. Synthesis and Characterization of High Energy Polymers.

    1981-03-31

    and characterization of new high energy elastomers. IV. References 1. J.C.W. Chien, T. Kohara , C. P. Lillya, T. Sarubbi, B.-H. Su and R. S. Miller, J...Catalyzed Nitromercuration of Diene Polymers, J.C.W. Chien, T. Kohara , C. P. Lillya, T. Sarubbi, B.-H. Su, and R. S. Miller, J. Polm.. Sci. Polym. Chem. Ed

  10. Zeolite from fly ash: synthesis and characterization

    Coal fly ash was used to synthesize X-type zeolite by alkali fusion followed by hydrothermal treatment. The synthesized zeolite was characterized using various techniques such as X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, BET method for surface area measurement etc.

  11. Synthesis, characterization, biological and electrical conductivity ...

    All the complexes have been characterized on the basis of elemental analyses, magnetic susceptibility measurement, electronic and IR spectra and thermogravimetric analysis. The IR spectral data suggested that the ligands behave as dibasic tridentate moiety towards the central metal ion coordinating through phenolic ...

  12. Synthesis and characterization of superabsorbent hydrogel based ...

    The hydrogels structure was characterized by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). The effect of grafting variables, that is, AA/AN weight ratio and concentration of MBA and APS, was systematically optimized to achieve a hydrogel with ...

  13. Synthesis, characterization and low frequency ac conduction

    in situ polymerization of aniline was carried out in the presence of fly ash (FA) to synthesize polyaniline/fly ash (PANI/FA) composites. The PANI/FA composites have been synthesized with various compositions (15, 20, 30 and 40 wt%) of FA in PANI. The composites, thus synthesized have been characterized by infrared ...

  14. Synthesis and Characterization of MAX Ceramics (MAXCERs)

    Nelson, Johnny Carl

    This research has focused on the design and development of novel multifunctional MAX reinforced ceramics (MAXCERs). These MAXCERs were manufactured with 1-50 vol% ratios of ceramics to MAX phases. Chapter II reports on the synthesis and tribological behavior of Ti3SiC2 matrix composites by incorporating (1 and 6 vol%) Al2O3, (1 and 5 vol%) BN, and (1 and 5 vol%) B4C ceramic particulate additives in the matrix. All the composites were fabricated by pressureless sintering by using 1 wt% Ni as a sintering agent at 1550 °C for 2 hours. SEM and XRD studies showed that Al2O3 is relatively inert in the Ti3SiC 2 matrix whereas BN and B4C reacted significantly with the Ti3 SiC2 matrix to form TiB2. Detailed tribological studies showed that Ti3SiC2-1wt%Ni (baseline) samples showed dual type tribological behavior where the friction coefficient (micro) was low ( 0.2) during stage 1, thereafter micro increased sharply and transitioned into stage 2 ( 0.8). The addition of Al2O3 as an additive had little effect on the tribological behavior, but the addition of B4C and BN was able to enhance the tribological behavior by increasing the transition distance (TD). Chapter III reports on the synthesis and tribological behavior of TiB2 matrix composites by incorporating (10, 30, and 50 vol%) Ti3SiC2 ceramic particulate additives in the matrix. The fabrication parameters were similar to the Ti3SiC2 samples from Chapter II. There was minimal reaction between the TiB2 and the Ti3SiC2. Detailed tribological studies showed that TiB2 (baseline) and TiB2-10%Ti 3SiC2 samples showed an average micro of 0.29 and 0.28, respectively. TiB2-30%Ti3SiC2 and TiB 2-50%Ti3SiC2 showed dual-type tribological behavior where micro was low ( 0.25) during stage 1, thereafter micro increased gradually and transitioned into stage 2 ( 0.6). Low wear rates were seen for all samples.

  15. Insitu synthesis of self-assembled gold nanoparticles on glass or silicon substrates through reactive inkjet printing

    Abulikemu, Mutalifu; Da'As, Eman Husni; Haverinen, Hanna M.; Cha, Dong Kyu; Malik, Mohammad A.; Jabbour, Ghassan Elie

    2013-01-01

    A facile and low cost method for the synthesis of self-assembled nanoparticles (NPs) with minimal size variation and chemical waste by using reactive inkjet printing was developed. Gold NPs with diameters as small as (8±2)nm can be made at low

  16. Detailed characterization of a Comparative Reactivity Method (CRM) instrument for ambient OH reactivity measurements: experiments vs. modeling

    Michoud, Vincent; Locoge, Nadine; Dusanter, Sébastien

    2015-04-01

    The Hydroxyl radical (OH) is the main daytime oxidant in the troposphere, leading to the oxidation of Volatile Organic Compounds (VOCs) and the formation of harmful pollutants such as ozone (O3) and Secondary Organic Aerosols (SOA). While OH plays a key role in tropospheric chemistry, recent studies have highlighted that there are still uncertainties associated with the OH budget, i.e the identification of sources and sinks and the quantification of production and loss rates of this radical. It has been demonstrated that ambient measurements of the total OH loss rate (also called total OH reactivity) can be used to identify and reduce these uncertainties. In this context, the Comparative Reactivity Method (CRM), developed by Sinha et al. (ACP, 2008), is a promising technique to measure total OH reactivity in ambient air and has already been used during several field campaigns. This technique relies on monitoring competitive reactions of OH with ambient trace gases and a reference compound (pyrrole) in a sampling reactor to derive ambient OH reactivity. However, this technique requires a complex data processing chain that has yet to be carefully investigated in the laboratory. In this study, we present a detailed characterization of a CRM instrument developed at Mines Douai, France. Experiments have been performed to investigate the dependence of the CRM response on humidity, ambient NOx levels, and the pyrrole-to-OH ratio inside the sampling reactor. Box modelling of the chemistry occurring in the reactor has also been performed to assess our theoretical understanding of the CRM measurement. This work shows that the CRM response is sensitive to both humidity and NOx, which can be accounted for during data processing using parameterizations depending on the pyrrole-to-OH ratio. The agreement observed between laboratory studies and model results suggests a good understanding of the chemistry occurring in the sampling reactor and gives confidence in the CRM

  17. Reactive-inspired ball-milling synthesis of an ODS steel: study of the influence of ball-milling and annealing

    Brocq, M.

    2010-10-01

    In the context of the development of new ODS (Oxide Dispersion Strengthened) steels as core materials in future nuclear reactors, we investigated a new process inspired by reactive ball-milling which consists in using YFe 3 andFe 2 O 3 as starting reactants instead of Y 2 O 3 to produce a dispersion of nano-oxides in a steel matrix and the influence of synthesis conditions on the nano-oxide characteristics were studied. For that aim, ODS steels were prepared by ball-milling and then annealed. Multi-scale characterizations were performed after each synthesis step, using notably atom probe tomography and small angle neutron scattering. The process inspired by reactive ball-milling was shown to be efficient for ODS steel synthesis, but it does not modify the nano-oxide characteristics as compared to those of oxides directly incorporated in the matrix by ball-milling. Broadly speaking, the nature of the starting oxygen bearing reactants has no influence on nano-oxide formation. Moreover, we showed that the nucleation of nano-oxides nucleation can start during milling and continues during annealing with a very fast kinetic. The final characteristics of nano-oxides formed in this way can be monitored through ball-milling parameters (intensity, temperature and atmosphere) and annealing parameters (duration and temperature). (author)

  18. Synthesis and characterization of porous calcium phosphate

    Granados C, F.; Serrano G, J.; Bonifacio M, J.

    2007-01-01

    The porous calcium phosphate was prepared by the continuous precipitation method using Ca(NO 3 ) 2 .4H 2 O and NH 4 H 2 PO 4 salts. The synthesized material was structurally and superficially characterized using the XRD, BET, IR TGA and SEM techniques. The obtained inorganic material was identified as calcium phosphate that presents a great specific area for what can be efficiently used as adsorbent material for adsorption studies in the radioactive wastes treatment present in aqueous solution. (Author)

  19. Synthesis of l-cysteine derivatives containing stable sulfur isotopes and application of this synthesis to reactive sulfur metabolome.

    Ono, Katsuhiko; Jung, Minkyung; Zhang, Tianli; Tsutsuki, Hiroyasu; Sezaki, Hiroshi; Ihara, Hideshi; Wei, Fan-Yan; Tomizawa, Kazuhito; Akaike, Takaaki; Sawa, Tomohiro

    2017-05-01

    Cysteine persulfide is an L-cysteine derivative having one additional sulfur atom bound to a cysteinyl thiol group, and it serves as a reactive sulfur species that regulates redox homeostasis in cells. Here, we describe a rapid and efficient method of synthesis of L-cysteine derivatives containing isotopic sulfur atoms and application of this method to a reactive sulfur metabolome. We used bacterial cysteine syntheses to incorporate isotopic sulfur atoms into the sulfhydryl moiety of L-cysteine. We cloned three cysteine synthases-CysE, CysK, and CysM-from the Gram-negative bacterium Salmonella enterica serovar Typhimurium LT2, and we generated their recombinant enzymes. We synthesized 34 S-labeled L-cysteine from O-acetyl-L-serine and 34 S-labeled sodium sulfide as substrates for the CysK or CysM reactions. Isotopic labeling of L-cysteine at both sulfur ( 34 S) and nitrogen ( 15 N) atoms was also achieved by performing enzyme reactions with 15 N-labeled L-serine, acetyl-CoA, and 34 S-labeled sodium sulfide in the presence of CysE and CysK. The present enzyme systems can be applied to syntheses of a series of L-cysteine derivatives including L-cystine, L-cystine persulfide, S-sulfo-L-cysteine, L-cysteine sulfonate, and L-selenocystine. We also prepared 34 S-labeled N-acetyl-L-cysteine (NAC) by incubating 34 S-labeled L-cysteine with acetyl coenzyme A in test tubes. Tandem mass spectrometric identification of low-molecular-weight thiols after monobromobimane derivatization revealed the endogenous occurrence of NAC in the cultured mammalian cells such as HeLa cells and J774.1 cells. Furthermore, we successfully demonstrated, by using 34 S-labeled NAC, metabolic conversion of NAC to glutathione and its persulfide, via intermediate formation of L-cysteine, in the cells. The approach using isotopic sulfur labeling combined with mass spectrometry may thus contribute to greater understanding of reactive sulfur metabolome and redox biology. Copyright © 2017 Elsevier Inc

  20. Chemical Characterization and Reactivity of Fuel-Oxidizer Reaction Product

    David, Dennis D.; Dee, Louis A.; Beeson, Harold D.

    1997-01-01

    Fuel-oxidizer reaction product (FORP), the product of incomplete reaction of monomethylhydrazine and nitrogen tetroxide propellants prepared under laboratory conditions and from firings of Shuttle Reaction Control System thrusters, has been characterized by chemical and thermal analysis. The composition of FORP is variable but falls within a limited range of compositions that depend on three factors: the fuel-oxidizer ratio at the time of formation; whether the composition of the post-formation atmosphere is reducing or oxidizing; and the reaction or post-reaction temperature. A typical composition contains methylhydrazinium nitrate, ammonium nitrate, methylammonium nitrate, and trace amounts of hydrazinium nitrate and 1,1-dimethylhydrazinium nitrate. Thermal decomposition reactions of the FORP compositions used in this study were unremarkable. Neither the various compositions of FORP, the pure major components of FORP, nor mixtures of FORP with propellant system corrosion products showed any unusual thermal activity when decomposed under laboratory conditions. Off-limit thruster operations were simulated by rapid mixing of liquid monomethylhydrazine and liquid nitrogen tetroxide in a confined space. These tests demonstrated that monomethylhydrazine, methylhydrazinium nitrate, ammonium nitrate, or Inconel corrosion products can induce a mixture of monomethylhydrazine and nitrogen tetroxide to produce component-damaging energies. Damaging events required FORP or metal salts to be present at the initial mixing of monomethylhydrazine and nitrogen tetroxide.

  1. Understanding reactivity of two newly synthetized imidazole derivatives by spectroscopic characterization and computational study

    Hossain, Mossaraf; Thomas, Renjith; Mary, Y. Sheena; Resmi, K. S.; Armaković, Stevan; Armaković, Sanja J.; Nanda, Ashis Kumar; Vijayakumar, G.; Van Alsenoy, C.

    2018-04-01

    Two newly synthetized imidazole derivatives (1-(4-methoxyphenyl)-4,5-dimethyl-1H-imidazole-2-yl acetate (MPDIA) and 1-(4-bromophenyl)-4,5-dimethyl-1H-imidazole-2-yl acetate (BPDIA)) have been prepared by solvent-free synthesis pathway and their specific spectroscopic and reactive properties have been discussed based on combined experimental and computational approaches. Aside of synthesis, experimental part of this work included measurements of IR, FT-Raman and NMR spectra. All of the aforementioned spectra were also obtained computationally, within the framework of density functional theory (DFT) approach. Additionally, DFT calculations have been used in order to investigate local reactivity properties based on molecular orbital theory, molecular electrostatic potential (MEP), average local ionization energy (ALIE), Fukui functions and bond dissociation energy (BDE). Molecular dynamics (MD) simulations have been used in order to obtain radial distribution functions (RDF), which were used for identification of the atoms with pronounced interactions with water molecules. MEP showed negative regions are mainly localized over N28, O29, O35 atoms, it is represent with red colour in rainbow color scheme for MPDIA and BPDIA (which are most reactive sites for electrophilic attack). The first order hyperpolarizabilities of MPDIA and BPDIA are 20.15 and 6.10 times that of the standard NLO material urea. Potential interaction with antihypertensive protein hydrolase.

  2. A Tracer Test to Characterize Treatment of TCE in a Permeable Reactive Barrier

    A tracer test was conducted to characterize the flow of ground water surrounding a permeable reactive barrier constructed with plant mulch (a biowall) at the OU-1 site on Altus Air Force Base, Oklahoma. This biowall is intended to intercept and treat ground water contaminated by ...

  3. Design and Synthesis of Bifunctional Oxime Reactivators of OP- inhibited Cholinesterase

    2013-08-01

    N O O OH N O O O O N OH O O N N O O N N N O N N N N N O N+ N N N OH MeOH/APS THP NaBH4 MsCl HN N p-Toluenesulfonic Acid Swern Oxidation H2N O S O O O...pendant general acid groups. Compound 8 has been delivered to ICD for testing (synthesis and characterization below). This strategy is in place to...as a THP ether and the trifluoromethylketone installed by coupling the organolithium with trifluoroacetylpiperidine. We again used our direct

  4. Organic nanomaterials: synthesis, characterization, and device applications

    Torres, Tomas

    2013-01-01

    Recent developments in nanoscience and nanotechnology have given rise to a new generation of functional organic nanomaterials with controlled morphology and well-defined properties, which enable a broad range of useful applications. This book explores some of the most important of these organic nanomaterials, describing how they are synthesized and characterized. Moreover, the book explains how researchers have incorporated organic nanomaterials into devices for real-world applications.Featuring contributions from an international team of leading nanoscientists, Organic Nanomaterials is divided into five parts:Part One introduces the fundamentals of nanomaterials and self-assembled nanostructuresPart Two examines carbon nanostructures—from fullerenes to carbon nanotubes to graphene—reporting on properties, theoretical studies, and applicationsPart Three investigates key aspects of some inorganic materials, self-assembled monolayers,...

  5. Synthesis and characterization of carbon nanotubes

    Ritschel, Manfred; Bartsch, Karl; Leonhardt, Albrecht; Graff, Andreas; Täschner, Christine; Fink, Jörg

    2001-11-01

    The catalytic chemical vapor deposition (CCVD) is a very promising process with respect to large scale production of different kinds of carbon nanostructures. By modifying the deposition temperature, the catalyst material and the hydrocarbon nanofibers with herringbone structure, multi-walled nanotubes with tubular structure and single-walled nanotubes were deposited. Furthermore, layers of aligned multi-walled nanotubes could be obtained on oxidized silicon substrates coated with thin sputtered metal layers (Co, permalloy) as well as onto WC-Co hardmetals by using the microwave assisted plasma CVD process (MWCVD). The obtained carbon modifications were characterized by scanning (SEM) and transmission (TEM) electron microscopy. The hydrogen storage capability of the nanofibers and nanotubes and the electron field emission of the nanotube layers was investigated.

  6. Synthesis and characterization of deuterated polyethylene

    Jia Xianbin; Luo Xuan; Chang Guanjun; Du Kai; Zhang Lin; Xie Zhengwei; Li Xinjuan; Lu Zaijun

    2009-01-01

    Due to its remarkable isotope effects, excellent kinetic stability towards C-D bond break, high degree of deuteration, and being non-radioactive, deuterated polyethylene (d-PE) is widely used in many fields, such as in inertially confined fusion (ICF) as target material, in production of low loss plastic optical fibers, and in study of the compatibility of different polymers. For the necessary of ICF, the d-PE was synthesized by the anionic polymerization and palladium-catalyzed hydrogenation. Furthermore, by the method of FTIR, 1H NMR and GPC, the deuterated ratio and structure of d-PE have been characterized. The results show that the d-PE has the high deuterated ratio and molecular weight, narrow molecular-weight distribution, the polymer material fits the basic necessary of ICF. (authors)

  7. Synthesis and characterization β-ketoamine ligands

    Zaid, Nurzati Amani Mohamed; Hassan, Nur Hasyareeda; Karim, Nurul Huda Abd

    2018-04-01

    β-ketoamine ligands are important members of heterodonor ligand because of their ease of preparation and modification of both steric and/or electronic effects. Complexes with β-ketoamine has received much less attention and there has been no study about this complex with β-ketoamine in ionic liquid reported. Two type of β-ketoamine ligands which are 4-amino-3-pentene-2-onato (A) and 3-amino-2-butenoic acid methyl ester (B) have been synthesized in this work. The resulting compound formed was characterized using standard spectroscopic and structural techniques which includes 1H and 13C, NMR spectroscopy and FTIR spectroscopy. The 1H and 13C NMR spectrum displayed all the expected signals with correct integration and multiplicity. And it is proved that there are some differences between two ligands as observed in NMR and FTIR spectrum.

  8. Energetic Di- and Trinitromethylpyridines: Synthesis and Characterization

    Yiying Zhang

    2017-12-01

    Full Text Available Pyridine derivatives based on the addition of trinitromethyl functional groups were synthesized by the reaction of N2O4 with the corresponding pyridinecarboxaldoximes, then they were converted into dinitromethylide hydrazinium salts. These energetic compounds were fully characterized by IR and NMR spectroscopy, elemental analysis, differential scanning calorimetry (DSC, and X-ray crystallography. These pyridine derivatives have good densities, positive enthalpies of formation, and acceptable sensitivity values. Theoretical calculations carried out using Gaussian 03 and EXPLO5 programs demonstrated good to excellent detonation velocities and pressures. Each of these compounds is superior in performance to TNT, while 2,6-bis(trinitromethylpyridine (D = 8700 m·s−1, P = 33.2 GPa shows comparable detonation performance to that of RDX, but its thermal stability is too low, making it inferior to RDX.

  9. Synthesis and Characterization Studies of MIL-101

    Emine Kaya EKİNCİ

    2017-12-01

    Full Text Available MIL-101 is a kind of Metal Organic Frameworks (MOFs, which have attracted much attention in the past decade due to its promising application in chemical industries. MIL-101 is also known as “Porous Chromium Terephthalate”. It has very high surface area and pore volume. MIL-101 exhibits exceptional stability against moisture and other chemicals and is composed of coordinately unsaturated Cr- sites with high concentration available for catalysis and adsorption. MIL-101 was synthesized by hydrothermal method and characterized by XRD, nitrogen adsorption and desorption analyses and SEM. XRD patterns show the presence of MIL-101’s crystal structure with high surface area (~2400 m2/g. Nitrogen adsorption-desorption analyzes showed that the material exhibited mesoporous material behavior.

  10. Plasma synthesis of titanium nitride, carbide and carbonitride nanoparticles by means of reactive anodic arc evaporation from solid titanium

    Kiesler, D.; Bastuck, T.; Theissmann, R.; Kruis, F. E.

    2015-01-01

    Plasma methods using the direct evaporation of a transition metal are well suited for the cost-efficient production of ceramic nanoparticles. In this paper, we report on the development of a simple setup for the production of titanium-ceramics by reactive anodic arc evaporation and the characterization of the aerosol as well as the nanopowder. It is the first report on TiC X N 1 − X synthesis in a simple anodic arc plasma. By means of extensive variations of the gas composition, it is shown that the composition of the particles can be tuned from titanium nitride over a titanium carbonitride phase (TiC X N 1 − X ) to titanium carbide as proven by XRD data. The composition of the plasma gas especially a very low concentration of hydrocarbons around 0.2 % of the total plasma gas is crucial to tune the composition and to avoid the formation of free carbon. Examination of the particles by HR-TEM shows that the material consists mostly of cubic single crystalline particles with mean sizes between 8 and 27 nm

  11. Characterization structural and morphology ZSM-5 zeolite by hydrothermal synthesis

    Silva, V.J.; Crispim, A.C.; Queiroz, M.B.; Laborde, H.M.; Rodrigues, M.G.F.; Menezes, R.R.

    2009-01-01

    Solid acids are catalytic materials commonly used in the chemical industry. Among these zeolites are the most important business processes including water treatment, gas separation, and cracking long hydrocarbon chains to produce high octane gasoline. Its synthesis, characterization and applications have been widely studied. The objective this study was to synthesize the ZSM-5 zeolite for future use in separation processes and catalysis. The zeolite ZSM-5 was prepared by hydrothermal synthesis at 170°C, using silica, deionized water and the director of structures (TPABr - tetrapropylammonium bromide). The materials were characterized by X ray diffraction (XRD), scanning electron microscopy (SEM) and semiquantitative chemical analysis by X ray fluorescence (XRF). According to the XRD was possible to observe the formation of ZSM-5 zeolite, with peaks intense and well defined. The SEM showed the formation of individual particles, clean, rounded shapes. (author)

  12. Synthesis and characterization of organically linked ZnO nanoparticles

    Chory, Christine; Riedel, Ingo; Parisi, Juergen [Energy and Semiconductor Research Laboratory (EHF), University of Oldenburg, Carl-von Ossietzky-Strasse 9-11, 26129 Oldenburg (Germany); Kruska, Carsten; Heimbrodt, Wolfram [Department of Physics and Material Sciences Center, Philipps-University Marburg, Renthof 5, 35032 Marburg (Germany); Feser, Clemens [NEXT ENERGY - EWE Research Centre for Energy Technology e.V., Carl-von Ossietzky-Strasse 15, 26129 Oldenburg (Germany); Beenken, Wichard J.D. [Department of Theoretical Physics I, Ilmenau University of Technology, Weimarer Strasse 25, 98693 Ilmenau (Germany); Hoppe, Harald [Department of Experimental Physics I, Ilmenau University of Technology, Weimarer Strasse 32, 98693 Ilmenau (Germany)

    2012-11-15

    We report on the solution-based synthesis and characterization of three-dimensional networks of ZnO nanoparticles where the formation of structures is achieved by covalently linking the nanocrystals with bifunctional organic ligands. The colloidal synthesis will be presented with application of two ligands that vary in size and binding sites. Furthermore we report on structural characterization of dried powders and thin films by means of X-ray diffraction and electron microscopy in order to examine the regularity of the structures. We also present first investigations of the optical properties and electrical conductance behavior in lateral direction of the differently linked hybrid ZnO networks. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  13. Synthesis and characterization of organically linked ZnO nanoparticles

    Chory, Christine; Riedel, Ingo; Parisi, Juergen; Kruska, Carsten; Heimbrodt, Wolfram; Feser, Clemens; Beenken, Wichard J.D.; Hoppe, Harald

    2012-01-01

    We report on the solution-based synthesis and characterization of three-dimensional networks of ZnO nanoparticles where the formation of structures is achieved by covalently linking the nanocrystals with bifunctional organic ligands. The colloidal synthesis will be presented with application of two ligands that vary in size and binding sites. Furthermore we report on structural characterization of dried powders and thin films by means of X-ray diffraction and electron microscopy in order to examine the regularity of the structures. We also present first investigations of the optical properties and electrical conductance behavior in lateral direction of the differently linked hybrid ZnO networks. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  14. Synthesis and characterizations of novel polymer electrolytes

    Chanthad, Chalathorn

    Polymer electrolytes are an important component of many electrochemical devices. The ability to control the structures, properties, and functions of polymer electrolytes remains a key subject for the development of next generation functional polymers. Taking advantage of synthetic strategies is a promising approach to achieve the desired chemical structures, morphologies, thermal, mechanical, and electrochemical properties. Therefore, the major goal of this thesis is to develop synthetic methods for of novel proton exchange membranes and ion conductive membranes. In Chapter 2, new classes of fluorinated polymer- polysilsesquioxane nanocomposites have been designed and synthesized. The synthetic method employed includes radical polymerization using the functional benzoyl peroxide initiator for the telechelic fluorinated polymers with perfluorosulfonic acids in the side chains and a subsequent in-situ sol-gel condensation of the prepared triethoxylsilane-terminated fluorinated polymers with alkoxide precursors. The properties of the composite membranes have been studied as a function of the content and structure of the fillers. The proton conductivity of the prepared membranes increases steadily with the addition of small amounts of the polysilsesquioxane fillers. In particular, the sulfopropylated polysilsesquioxane based nanocomposites display proton conductivities greater than Nafion. This is attributed to the presence of pendant sulfonic acids in the fillers, which increases ion-exchange capacity and offers continuous proton transport channels between the fillers and the polymer matrix. The methanol permeability of the prepared membranes has also been examined. Lower methanol permeability and higher electrochemical selectivity than those of Nafion have been demonstrated in the polysilsesquioxane based nanocomposites. In Chapter 3, the synthesis of a new class of ionic liquid-containing triblock copolymers with fluoropolymer mid-block and imidazolium methacrylate

  15. Synthesis and characterization of Au incorporated Alq3 nanowires

    Khan, Mohammad Bilal; Ahmad, Sultan; Parwaz, M.; Rahul, Khan, Zishan H.

    2018-05-01

    We report the synthesis and characterization of pure and Au incorporated Alq3 nanowires. These nanowires are synthesized using thermal vapor transport method. The luminescence intensity of Au incorporated Alq3 nanowires are recorded to be higher than that of pure Alq3 nanowires, which is found to increase with the increase in Au concentration. Fluorescence quenching is also observed when Au concentration is increased beyond the certain limit.

  16. Electronic, electrical and magnetic ceramics synthesis and characterization

    Calix, V.S.; Saligan, P.P.; Naval, P.C.

    1989-01-01

    This paper describes the research and development activities of the Philippine Nuclear Research Institute (PNRI) on the synthesis and characterization of soft and hard ferrites and some beta alumina type superionic conductor materials. XRD, XRF and Moessbauer effect spectrometry are used to determine the structure phases, compositions and some magnetic properties of the materials. Effects of composition and preparation methods on the bulk electronic and magnetic properties are also discussed. (Auth.). 6 figs.; 3 tabs

  17. Platinum boride nanowires: Synthesis and characterization

    Ding Zhanhui; Qiu Lixia; Zhang Jian; Yao Bin; Cui Tian; Guan Weiming; Zheng Weitao; Wang Wenquan; Zhao Xudong; Liu Xiaoyang

    2012-01-01

    Highlights: ► Platinum boride nanowires have been synthesized via the direct current arc discharge method. ► XRD, TEM and SAED indicate that the nanowires are single-crystal PtB. ► Two broad photoluminescence emission peaks at about 586 nm and 626 nm have been observed in the PL spectroscopy of PtB nanowires. - Abstract: Platinum boride (PtB) nanowires have been successfully fabricated with direct current arc discharge method using a milled mixture of platinum (Pt) and boron nitride (BN) powders. X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to characterize the compositions, morphology, and structures of the samples. The results show that PtB nanowires are 30–50 nm thick and 20–30 μm long. TEM and selected area electron diffraction (SAED) patterns identify that the PtB nanowires are single-crystalline in nature. A growth mechanism based on vapor–liquid–solid (VLS) process is proposed for the formation of nanowires.

  18. Solvothermal synthesis and characterization of CZTS nanocrystals

    Dumasiya, Ajay; Shah, N. M.

    2017-05-01

    Cu2ZnSnS4 (CZTS) is a promising thin film absorber material for low cost solar cell applications. CZTS nanoparticle ink synthesized using solvothermal route is an attractive option to deposit absorber layer using screen printing or spin coating method in CZTS thin film solar cell. In this study we have synthesized CZTS nanocrystals using solvothermal method from aqueous solution of Copper nitrate [Cu(NO3)2], Zinc nitrate [Zn(NO3)2], tin chloride [SnCl4] and thiourea with varying concentration of Cu(NO3)2 (viz 0.82 mmol,1.4 mmol, 1.7 mmol) keeping concentrations of rest of solutions constant. As synthesized CZTS nanocrystals are characterized using Energy Dispersive Analysis of X-rays (EDAX) to verify stoichiometry of elements. Analysis of EDAX data suggests that CZTS nanocrystals having Copper nitrate [Cu (NO3)2] concentration of 1.4 m mole is near stoichiometric. X-ray diffraction analysis study of CZTS nanocrystals having Copper nitrate [Cu (NO3)2] concentration of 1.4 m mole reveals the preferred orientation of the grains in (112), (220) and (312) direction confirming Kesterite structure of CZTS.

  19. Synthesis and characterization of biomorphic ceramics

    Rambo, Carlos Renato

    2001-01-01

    Biotemplating represents a recently developed technology for manufacturing of biomorphous ceramics from naturally grown plant structures. This approach allows the production of ceramic materials with cellular structure, where the microstructural features of the ceramic product are similar to the native plant. After processing, the biomorphic ceramic exhibits directed pore morphology in the micrometer range. Biomorphic SiC fibers were produced from bamboo by carbothermal reduction of SiO 2 originally present in the bamboo structure. Bamboo pieces were heated up to 1500 deg C in argon to promote the reaction between carbon and silica. Biomorphic alumina, mullite and zirconia ceramics were manufactured via the sol-gel route by repeated infiltration of low viscous oxide precursors (sols) into rattan, pine and bamboo structures. The raw samples were pyrolyzed at 800 deg C in nitrogen for 1h and subsequently annealed at 1550 deg C in air. The microstructure and physical properties of the biomorphic ceramics were characterized by X-ray diffraction (XRD) and high temperature-XRD, scanning electron microscopy (SEM), porosimetry and picnometry. Thermal analysis (TGA/DTA) was performed on the infiltrated samples in order to evaluate the reactions and the total weight loss during the thermal process. The mechanical properties were evaluated by compressive strength tests. In contrast to conventional processed ceramic foam of similar porosity, the microstructure highly porous biomorphic ceramics shows uniaxial pore morphology with anisotropic properties. These properties are favorable for applications in catalyst support, filters or low-density heat insulation structures, or as biomaterials. (author)

  20. Synthesis and characterization of luminescence magnetic nanocomposite

    Kiplagat, Ayabei [DST/Mintek Nanotechnology Innovation Centre, Department of Chemistry, University of the Western Cape, Private Bag X17, Bellville (South Africa); Onani, Martin O., E-mail: monani@uwc.ac.za [DST/Mintek Nanotechnology Innovation Centre, Department of Chemistry, University of the Western Cape, Private Bag X17, Bellville (South Africa); Meyer, Mervin [DST/Mintek Nanotechnology Innovation Centre, Department of Biotechnology, University of the Western Cape, Private Bag X17, Bellville (South Africa); Akenga, Teresa A. [Department of Chemistry, University of Eldoret, P.O. Box 1125, Eldoret (Kenya); Dejene, Francis B. [Department of Physics, University of the Free State, QwaQwa Campus, Private Bag X13, Phuthadithaba 9866 (South Africa)

    2016-01-01

    We report a new type of indium based quantum dots which were conjugated to the magnetic Fe{sub 2}O{sub 3} nanoparticles. They were characterized by photoluminescence (PL), high resolution transmission electron microscopy (HRTEM), superconducting quantum interference device (SQUID) and fourier transform infra-red (FTIR). The photoluminescence characteristics of the coupled and uncoupled indium based quantum dots were investigated to determine whether the fluorescing property could be retained in the bifunctional system. Generally, the PL intensity of the quantum dots was observed to reduce significantly and with huge red shift most probably due to quenching effects for the MNPs. The average size of the coupled nanoparticles were found to range between 4 and 5 nm for the quantum dots and range of 6–13 nm for the Fe{sub 2}O{sub 3} magnetic nanoparticles as revealed by both HRTEM and XRD. The highest magnetic saturation reached for both bare and functionalized magnetic nanoparticles was 68.58 emu/g. The FTIR data revealed that the postulated functional groups were actually present in both the bare and functionalized nanoparticles. For instance, Fe–O was observed at around 580 cm{sup −1}, O–H at 3432 cm{sup −1} and thiol group at 2929 cm{sup −1} for meso-2,3-dimercaptosuccinic acid capped Fe{sub 2}O{sub 3} magnetic nanoparticles. The energy dispersive spectroscopy (EDS) also confirmed that all the elements of the nanocomposite were actually present in the designed material.

  1. Fracture Characterization in Reactive Fluid-Fractured Rock Systems Using Tracer Transport Data

    Mukhopadhyay, S.

    2014-12-01

    Fractures, whether natural or engineered, exert significant controls over resource exploitation from contemporary energy sources including enhanced geothermal systems and unconventional oil and gas reserves. Consequently, fracture characterization, i.e., estimating the permeability, connectivity, and spacing of the fractures is of critical importance for determining the viability of any energy recovery program. While some progress has recently been made towards estimating these critical fracture parameters, significant uncertainties still remain. A review of tracer technology, which has a long history in fracture characterization, reveals that uncertainties exist in the estimated parameters not only because of paucity of scale-specific data but also because of knowledge gaps in the interpretation methods, particularly in interpretation of tracer data in reactive fluid-rock systems. We have recently demonstrated that the transient tracer evolution signatures in reactive fluid-rock systems are significantly different from those in non-reactive systems (Mukhopadhyay et al., 2013, 2014). For example, the tracer breakthrough curves in reactive fluid-fractured rock systems are expected to exhibit a long pseudo-state condition, during which tracer concentration does not change by any appreciable amount with passage of time. Such a pseudo-steady state condition is not observed in a non-reactive system. In this paper, we show that the presence of this pseudo-steady state condition in tracer breakthrough patterns in reactive fluid-rock systems can have important connotations for fracture characterization. We show that the time of onset of the pseudo-steady state condition and the value of tracer concentration in the pseudo-state condition can be used to reliably estimate fracture spacing and fracture-matrix interface areas.

  2. Cloning and characterization of profilin (Pru du 4), a cross-reactive almond (Prunus dulcis) allergen.

    Tawde, Pallavi; Venkatesh, Yeldur P; Wang, Fang; Teuber, Suzanne S; Sathe, Shridhar K; Roux, Kenneth H

    2006-10-01

    The identity of allergenic almond proteins is incomplete. Our objective was to characterize patient IgE reactivity to a recombinant and corresponding native almond allergen. An almond cDNA library was screened with sera from patients with allergy for IgE binding proteins. Two reactive clones were sequenced, and 1 was expressed. The expressed recombinant allergen and its native counterpart (purified from unprocessed almond flour) were assayed by 1-dimensional and 2-dimensional gel electrophoresis, dot blot, and ELISA, and screened for cross-reactivity with grass profilin. The 2 selected clones encoded profilin (designated Pru du 4) sequences that differed by 2 silent mutations. By dot-blot analyses, 6 of 18 patient sera (33%) reacted with the recombinant Pru du 4 protein, and 8 of 18 (44%) reacted with the native form. ELISA results were similar. Almond and ryegrass profilins were mutually inhibitable. Two-dimensional immunoblotting revealed the presence of more than 1 native almond profilin isoform. The strength of reactivity of some patients' serum IgE differed markedly between assays and between native and recombinant profilins. Almond nut profilin is an IgE-binding food protein that is cross-reactive with grass pollen profilin and is susceptible to denaturation, resulting in variable reactivity between assay types and between patients. Serum IgE of nearly half of the tested patients with almond allergy reacts with almond nut profilin. Because most patients also had pollinosis, the well-known cross-reactivity between pollen and food profilins could account for this pattern of reactivity.

  3. Enrichment of reactive macerals in coal: its characterization and utilization in coke making

    Nag, Debjani; Kopparthi, P.; Dash, P. S.; Saxena, V. K.; Chandra, S.

    2018-01-01

    Macerals in coal are of different types: reactive and inert. These macerals are differ in their physical and chemical properties. Column flotation method has been used to separate the reactive macerals in a non-coking coal. The enriched coal is then characterized in order to understand the changes in the coking potential by different techniques. It is then used in making of metallurgical coke by proper blending with other coals. Enriched coal enhance the properties of metallurgical coke. This shows a path of utilization of non-coking coal in metallurgical coke making.

  4. Intra-individual variability in cerebrovascular and respiratory chemosensitivity: Can we characterize a chemoreflex "reactivity profile"?

    Borle, Kennedy J; Pfoh, Jamie R; Boulet, Lindsey M; Abrosimova, Maria; Tymko, Michael M; Skow, Rachel J; Varner, Amy; Day, Trevor A

    2017-08-01

    Intra-individual variability in the magnitude of human cerebrovascular and respiratory chemoreflex responses is largely unexplored. By comparing response magnitudes of cerebrovascular CO 2 reactivity (CVR; middle and posterior cerebral arteries; MCA, PCA), central (CCR; CO 2 ) and peripheral respiratory chemoreflexes (PCR; CO 2 and O 2 ), we tested the hypothesis that a within-individual reactivity magnitude profile could be characterized. The magnitudes of CVR and CCR were tested with hyperoxic rebreathing and PCR magnitudes were tested through transient respiratory tests (TT-CO 2 , hypercapnia; TT-N 2 , hypoxia). No significant intra-individual relationships were found between CCR vs. CVR (MCA and PCA), CCR vs. PCR (TT-N 2 or TT-CO 2 ) (r0.3) response magnitudes. Statistically significant relationships were found between MCA vs. PCA reactivity (r=0.45, Pvariability that exists in human cerebrovascular and respiratory chemoreflexes. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Synthesis and characterization of photoswitchable fluorescent silica nanoparticles.

    Fölling, Jonas; Polyakova, Svetlana; Belov, Vladimir; van Blaaderen, Alfons; Bossi, Mariano L; Hell, Stefan W

    2008-01-01

    We have designed and synthesized a new functional (amino reactive) highly efficient fluorescent molecular switch (FMS) with a photochromic diarylethene and a rhodamine fluorescent dye. The reactive group in this FMS -N-hydroxysuccinimide ester- allows selective labeling of amino containing molecules or other materials. In ethanolic solutions, the compound displays a large fluorescent quantum yield of 52 % and a large fluorescence modulation ratio (94 %) between two states that may be interconverted with red and near-UV light. Silica nanoparticles incorporating the new FMS were prepared and characterized, and their spectroscopic and switching properties were also studied. The dye retained its properties after the incorporation into the silica, thereby allowing light-induced reversible high modulation of the fluorescence signal of a single particle for up to 60 cycles, before undergoing irreversible photobleaching. Some applications of these particles in fluorescence microscopy are also demonstrated. In particular, subdiffraction images of nanoparticles were obtained, in the focal plane of a confocal microscope.

  6. Synthesis and characterization of liquid crystals and their thermoset films

    Ahn, Yong-Ho; Jung, Myung-Sup; Chang, Jin-Hae

    2010-01-01

    We prepared a series of aromatic liquid crystals (LCs) based on aromatic ester units with the reactive end groups methyl-maleimide and nadimide, and the resulting LCs were thermally cross-linked to produce liquid crystalline thermoset (LCT) films by means of solution-casting and heat treatment. The synthesized LCs and LCTs were characterized with Fourier transform infrared (FT-IR) spectroscopy, 1 H nuclear magnetic resonance (NMR), differential scanning calorimetry (DSC), thermomechanical analysis (TMA), and polarizing optical microscopy with a hot stage. We found that all these LCs form nematic phases. The coefficients of thermal expansion (CTEs) of the LCT films are strongly affected by the reactive end group and the mesogen units in their main-chain structures. The methyl-maleimide-terminated biphenyl LCT was found to have the lowest CTE.

  7. Lanthanide phosphonates: Synthesis, thermal stability and magnetic characterization

    Amghouz, Z., E-mail: amghouz.uo@uniovi.es [Departamentos de Quimica Fisica y Analitica y Quimica Organica e Inorganica, Universidad de Oviedo - CINN, 33006 Oviedo (Spain); Garcia, J.R.; Garcia-Granda, S. [Departamentos de Quimica Fisica y Analitica y Quimica Organica e Inorganica, Universidad de Oviedo - CINN, 33006 Oviedo (Spain); Clearfield, A. [Department of Chemistry, Texas A and M University, College Station, TX 77842-3012 (United States); Rodriguez Fernandez, J.; Pedro, I. de [CITIMAC, Facultad de Ciencias, Universidad de Cantabria, 39005 Santander (Spain); Blanco, J.A. [Departamento de Fisica, Universidad de Oviedo, 33007 Oviedo (Spain)

    2012-09-25

    Highlights: Black-Right-Pointing-Pointer Report of the complete series of lanthanide 1,4-phenylbis(phosphonate). Black-Right-Pointing-Pointer Synthesis under conventional hydrothermal synthesis or microwave-assisted hydrothermal synthesis. Black-Right-Pointing-Pointer Cation size is the key factor for the structural and particles size variations. Black-Right-Pointing-Pointer Thermal behaviour is characterized by unusual very high thermal stability. - Abstract: Series of novel organic-inorganic hybrids materials based on trivalent lanthanides (Ln = Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu) and 1,4-phenylbis(phosphonate) obtained under hydrothermal conditions either by oven heat or microwave irradiation. The anhydrous compounds containing La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, and Ho, are isostructural. However, the compounds based on Y, Er, Tm, Yb, and Lu are hydrated and their structures have not yet been solved. The series of compounds are characterized by PXRD, TEM, SEM-EDX and thermal analyses (TG-MS and DSC). TEM study show a variable particles size with a minimum mean-particle size of ca. 30 nm. These compounds exhibit unusual very high thermal stability. The size of particles and the thermal stability are depending on lanthanide(III) cation features. All the investigated materials show paramagnetic behaviour. The magnetic susceptibility data follow a Curie-Weiss laws with paramagnetic effective moments in good agreement with those expected for Ln{sup 3+} free ions.

  8. Synthesis and characterization of activated lithium fluoride with silver

    Encarnacion E, E. K.; Guerrero S, Z.; Reyes A, J.

    2017-10-01

    The present work shows part of the results obtained in the development of the research that has been carried out since 2015 entitled -Synthesis and characterization of new thermoluminescent materials for the radiation dosimetry and its applications in health-. In the development of this research, the synthesis of crystals of pure lithium fluoride (LiF) and activated with different concentrations of silver (LiF:Ag); synthesized samples are also presented using different temperatures, as well as varying the concentration of the solvent (water-ethanol). The synthesized materials were characterized through different techniques: scanning electron microscopy and X-ray diffraction. Specifically, the results of the calculation of the size of the LiF crystals are presented using the Scherrer equation. Within the results, a dependence on the size of the crystals is highlighted by means of the following factors: the amount of activator in the sample, the temperature at which the sample was synthesized, as well as the amount of solvent in the synthesis. The samples have a simple cubic crystalline phase. (Author)

  9. Synthesis and characterization of poly aniline for electrochemical biosensor construction

    Magalhaes, Gleice S.L.; Southgate, Erica F.; Alhadeff, Eliana M.; Guimaraes, Maria Jose O.C.

    2011-01-01

    Conductors polymers have many attractive interests to the industry due their highly technological applications. This work treats specially of polyaniline because it's large electrical conductivity, electrochemical properties, associate to the chemical stability in environmental conditions and synthesis facility. The main of this work is the application in a construction of an electrochemical biosensor for ethanol detection and quantification. Different conditions of synthesis of the conductor emeraldine polyaniline form were studied, investigated the influence of the dopant agent and the reactional environment conditions temperature on the reaction yield and conductivities. The polyaniline that showed the best conductivity were characterized by differential and thermal gravimetric analysis, infrared spectroscopy, X ray diffraction, and cycle voltammetry, comparing with the commercial polyaniline. (author)

  10. Synthesis, crystal structure and reactivity studies of iron complexes with pybox ligands

    Chen, Tao; Yang, Limin; Gong, Dirong; Huang, Kuo-Wei

    2014-01-01

    Iron(II) complexes, [Fe(2,6-bis(4,4-dimethyl-1,3-oxazolin-2-yl)pyridine)Cl2] ((Fe(Me2-pybox)Cl2), 3) and [Fe(2,6-bis(4,4-diphenyl-1,3-oxazolin-2-yl)pyridine)Cl2] ((Fe(Ph2-pybox)Cl2), 4), have been synthesized and characterized by X-ray crystallographic analysis. Upon treatment of complex 3 with silver triflate and 4 with acetonitrile, [Fe(Me2-pybox)(CH3CN)OTf2] (5) and [Fe(Ph2-pybox)(CH3CN)2Cl][FeCl3] (6) were obtained, respectively. The bulkier phenyl substitutes were found not only to cause the elongation of the N-Fe bonds but also influence the reactivity of the Fe center.

  11. Synthesis, crystal structure and reactivity studies of iron complexes with pybox ligands

    Chen, Tao

    2014-11-01

    Iron(II) complexes, [Fe(2,6-bis(4,4-dimethyl-1,3-oxazolin-2-yl)pyridine)Cl2] ((Fe(Me2-pybox)Cl2), 3) and [Fe(2,6-bis(4,4-diphenyl-1,3-oxazolin-2-yl)pyridine)Cl2] ((Fe(Ph2-pybox)Cl2), 4), have been synthesized and characterized by X-ray crystallographic analysis. Upon treatment of complex 3 with silver triflate and 4 with acetonitrile, [Fe(Me2-pybox)(CH3CN)OTf2] (5) and [Fe(Ph2-pybox)(CH3CN)2Cl][FeCl3] (6) were obtained, respectively. The bulkier phenyl substitutes were found not only to cause the elongation of the N-Fe bonds but also influence the reactivity of the Fe center.

  12. Synthesis and characterization of noble metal–titania core–shell nanostructures with tunable shell thickness

    Bartosz Bartosewicz

    2017-10-01

    Full Text Available Core–shell nanostructures have found applications in many fields, including surface enhanced spectroscopy, catalysis and solar cells. Titania-coated noble metal nanoparticles, which combine the surface plasmon resonance properties of the core and the photoactivity of the shell, have great potential for these applications. However, the controllable synthesis of such nanostructures remains a challenge due to the high reactivity of titania precursors. Hence, a simple titania coating method that would allow better control over the shell formation is desired. A sol–gel based titania coating method, which allows control over the shell thickness, was developed and applied to the synthesis of Ag@TiO2 and Au@TiO2 with various shell thicknesses. The morphology of the synthesized structures was investigated using scanning electron microscopy (SEM. Their sizes and shell thicknesses were determined using tunable resistive pulse sensing (TRPS technique. The optical properties of the synthesized structures were characterized using UV–vis spectroscopy. Ag@TiO2 and Au@TiO2 structures with shell thickness in the range of ≈40–70 nm and 90 nm, for the Ag and Au nanostructures respectively, were prepared using a method we developed and adapted, consisting of a change in the titania precursor concentration. The synthesized nanostructures exhibited significant absorption in the UV–vis range. The TRPS technique was shown to be a very useful tool for the characterization of metal–metal oxide core–shell nanostructures.

  13. Characterization of nano-crystalline ZrO{sub 2} synthesized via reactive plasma processing

    Jayakumar, S., E-mail: sjayakumar.physics@gmail.com [Research and Development Centre, Bharathiar University, Coimbatore 641 014 (India); Ananthapadmanabhan, P.V. [Laser and Plasma Technology Division, BARC, Trombay, Mumbai 400 085 (India); Perumal, K. [Department of Physics, Sri Ramakrishna Mission Vidyalaya College of Arts and Science, Coimbatore 641 020 India (India); Thiyagarajan, T.K. [Laser and Plasma Technology Division, BARC, Trombay, Mumbai 400 085 (India); Mishra, S.C. [Department of Metallurgical and Materials Engg, National Institute of Technology, Rourkela 769 008 (India); Su, L.T.; Tok, A.I.Y.; Guo, J. [School of Materials Science and Engg, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639 798 (Singapore)

    2011-07-25

    Highlights: > Direct conversion of micron-sized zirconium hydride powder to nanocrystalline ZrO{sub 2} powder. > The experimental approach uses reactive plasma processing technique. > The product has been characterized by various analytical tools to support the findings. - Abstract: Nano-crystalline ZrO{sub 2} powder has been synthesized via reactive plasma processing. The synthesized ZrO{sub 2} powders were characterized by X-ray diffraction (XRD), Raman spectroscopy, transmission electron microscopy (TEM) and FTIR spectroscopy. The synthesized powder consists of a mixture of tetragonal and monoclinic phases of zirconia. Average crystallite size calculated from the XRD pattern shows that particles with crystallite size 20 nm or less than 20 nm are in tetragonal phase, whereas particles greater than 20 nm are in the monoclinic phase. TEM results show that particles have spherical morphology with maximum percentage of particles distributed in a narrow size from about 15 nm to 30 nm.

  14. Synthesis and characterization of energetic thermoplastic elastomers for propellant formulations

    Aparecida M. Kawamoto

    2009-01-01

    Full Text Available Synthesis and characterization of energetic ABA-type thermoplastic elastomers for propellant formulations has been carried out. Following the working plan elaborated, the synthesis and characterization of Poly 3- bromomethyl-3-methyl oxetane (PolyBrMMO, Poly 3- azidomethyl-3-methyl oxetane (PolyAMMO, Poly 3,3-bis-azidomethyl oxetane (PolyBAMO and Copolymer PolyBAMO/AMMO (by TDI end capping has been successfully performed. The thermoplastic elastomers (TPEs were synthesized using the chain elongation process PolyAMMO, GAP and PolyBAMO by diisocyanates. In this method 2.4-toluene diisocyanate (TDI is used to link block A (hard and mono- functional to B (soft and di-functional. For the hard A-block we used PolyBAMO and for the soft B-block we used PolyAMMO or GAP.This is a joint project set up, some years ago, between the Chemistry Division of the Institute of Aeronautics and Space (IAE - subordinated to the Brazilian Ministry of Defense - and the Fraunhofer Institut Chemische Technologie (ICT, in Germany. The products were characterized by different techniques as IR- and (1H,13CNMR spectroscopies, elemental and thermal analyses. New methodologies based on FT-IR analysis have been developed as an alternative for the determination of the molecular weight and CHNO content of the energetic polymers.

  15. Synthesis and characterization of "1"3C_3-tristearin

    Wu Hangyu; Lin Lin; Li Lei; Chen Dazhou

    2011-01-01

    A highly efficient synthesis of "1"3C_3 labeled triglycerides of stearic acids from "1"3C_3-glycerol and stearic acids, by immobilized lipase-catalyzed in solvent-free medium was described. The structure of the product were characterized by fourier transform infrared spectrum (FT-IR), nuclear magnetic resonance (NMR), mass spectra (MS). The results showed that triglycerides of stearic acids contained three "1"3C atoms. The isotope abundance of "1"3C_3-tristearin was more than 99% and the yield was 80% of "1"3C_3-tristearin through calculation. Chemical purity (> 98%) was obtained by differential scanning calorimetry (DSC). (authors)

  16. Synthesis characterization, and properties of rubber lattices; a review

    Khan, S.M.; Chughtai, A.; Sattar, A.

    2008-01-01

    Latex is a stable dispersion of polymeric material in an aqueous medium. Lattices are present in natural as well as in synthetic forms. The range of applications of latex is extensive in carpet underlay, fabric back-coating, paper and paints coatings, adhesive, binder, leather finish, floor polish, waterproof clothing, bounded fiber, pigment printing, latex thread, cement and asphalt, foam scraps binders, can closure, thickeners, box toes and shoes counters, sealant and mastics, modifiers, protein reduction, enzyme treatment and peroxide vulcanization. In this review we are presenting synthesis, characterization, properties, manufacturing and processing of latex. (author)

  17. Boronate esters: Synthesis, characterization and molecular base receptor analysis

    Gómez-Jaimes, Gelen; Barba, Victor

    2014-10-01

    The synthesis of three boronate esters obtained by reacting 4-fluorophenylboronic (1), 4-iodophenylboronic (2) and 3,4-chlorophenylboronic (3) acids with 2,4,5-trihidroxybenzaldehyde is reported. The structural characterization was determined by spectroscopic and spectrometric techniques. The boron atom was evaluated to acts as Lewis acid center in the reaction with pyridine (Py), triethylamine (TEA) and fluoride anion (F-). The titration method was followed by UV-Vis and 11B NMR spectroscopy; results indicate the good interaction with the fluoride ion but poor coordination towards pyridine in solution.

  18. Synthesis and characterization of the polyaniline dopant Schiff base

    Mirian Y. Matsumoto

    2012-06-01

    Full Text Available The Schiff base, N-salicilidenoanilina was used as dopant to induce polymerization of aniline and thus preparing polyaniline (PAni. The different conditions of preparation, including Schiff base structure, and the dosage of acidity reaction medium, were investigated to discuss the influence of these conditions relative conductivity of the resulting samples. The products were also characterized by Fourier transform infrared (FTIR, ultraviolet-visible (UV-Vis, electrochemical impedance spectroscopy (EIE. The results showed the synthesis conditions play an important in the formation and the final properties of the polyaniline

  19. Synthesis and Characterization of Biscoumarin and Benzopyrano Dicoumarin Derivatives

    Nik Khairunissa' Nik Abdullah Zawawi; Muhammad Taha; Norizan Ahmat; Nor Hadiani Ismail; Nik Khairunissa' Nik Abdullah Zawawi; Muhammad Taha; Norizan Ahmat; Nor Hadiani Ismail

    2016-01-01

    The wide-ranging biological activities of 4-hydroxycoumarin have stimulated considerable interest in this class of compounds, and various biscoumarin derivatives have been synthesized. Recently, a number of methods have been reported for the synthesis of biscoumarin by the reaction of 4-hydroxycoumarin and various aldehydes in the presence of catalysts. In the present study, a new series of biscoumarin and benzopyrano dicoumarin were synthesized and physically characterized by nuclear magnetic resonane ( 1 H and 13 C NMR), fourier transform infrared spectroscopy (FTIR), mass spectrometry (MS) and melting point. (author)

  20. Synthesis and characterization of cobalt sulfide nanoparticles by sonochemical method

    Muradov, Mustafa B.; Balayeva, Ofeliya O.; Azizov, Abdulsaid A.; Maharramov, Abel M.; Qahramanli, Lala R.; Eyvazova, Goncha M.; Aghamaliyev, Zohrab A.

    2018-03-01

    Convenient and environmentally friendly synthesis of Co9S8/PVA, CoxSy/EG and CoxSy/3-MPA nanocomposites were carried out in the presence of ultrasonic irradiation by the liquid phase synthesis of the sonochemical method. For the synthesis, cobalt acetate tetrahydrate [Co(CH3COO)2·4H2O] and sodium sulfide (Na2S·9H2O) were used as a cobalt and sulfur precursor, respectively. Polyvinyl alcohol (PVA), ethylene glycol (EG) and 3-mercaptopropionic acid (3-MPA) were used as a capping agent and surfactant. The structural, optical properties and morphology of nanocomposites were characterized using X-ray diffractometer (XRD), Ultraviolet/Visible Spectroscopy (UV-Vis), Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The optical band gap of Co9S8/PVA is 1.81 eV and for CoxSy/EG is 2.42 eV, where the direct band gap of bulk cobalt sulfide is (0.78-0.9 eV). The wide band gap indicates that synthesised nanocomposites can be used in the fabrication of optical and photonic devices. The growth mechanisms of the Co9S8, CoS2 and Co3S4 nanoparticles were discussed by the reactions. The effects of sonication time and annealing temperature on the properties of the nanoparticles have been studied in detail.

  1. Sol – Gel synthesis and characterization of magnesium peroxide nanoparticles

    Jaison, J; Chan, Y S; Ashok raja, C; Balakumar, S

    2015-01-01

    Magnesium peroxide is an excellent source of oxygen in agriculture applications, for instance it is used in waste management as a material for soil bioremediation to remove contaminants from polluted underground water, biological wastes treatment to break down hydrocarbon, etc. In the present study, sol-gel synthesis of magnesium peroxide (MgO 2 ) nanoparticles is reported. Magnesium peroxide is odourless; fine peroxide which releases oxygen when reacts with water. During the sol-gel synthesis, the magnesium malonate intermediate is formed which was then calcinated to obtain MgO 2 nanoparticles. The synthesized nanoparticles were characterized using Thermo gravimetric -Differential Thermal Analysis (TG- DTA), X-Ray Diffraction studies (XRD) and High Resolution Transmission Electron Microscope (HRTEM). Our study provides a clear insight that the formation of magnesium malonate during the synthesis was due to the reaction between magnesium acetate, oxalic acid and ethanol. In our study, we can conclude that the calcination temperature has a strong influence on particle size, morphology, monodispersity and the chemistry of the particles. (paper)

  2. Materials Research Society Symposium Proceedings Volume 635. Anisotropic Nanoparticles - Synthesis, Characterization and Applications

    Lyon, L

    2000-01-01

    This volume contains a series of papers originally presented at Symposium C, "Anisotropic Nanoparticles Synthesis, Characterization and Applications," at the 2000 MRS Fall Meeting in Boston, Massachusetts...

  3. Electrochemical synthesis and characterization of copper (I oxide

    Bugarinović Sanja J.

    2009-01-01

    Full Text Available The quest and need for clean and economical energy sources have increased interest in the development of thin film cells technologies. Electrochemical deposition is an attractive method for synthesis of thin films. It offers the advantages of low synthesis temperature, low cost and high purity. Copper (I oxide or cuprous oxide is an oxide semiconductor which is used as the anodic material in the form of thin film in lithium batteries and solar cells. The cathodic process of synthesis of cuprous oxide thin film is carried out in a potentiostatic mode from the organic electrolyte. The process parameters are chosen in that way to accomplish maximum difference between the potentials at which Cu2O and CuO are obtained. The electrochemical characterization was carried out by cyclic voltammetry. The electrodeposition techniques are particularly well suited for the deposition of single elements but it is also possible to carry out simultaneous depositions of several elements and syntheses of well-defined alternating layers of metals and oxides with thicknesses down to a few nm. Nanomaterials exhibit novel physical properties and play an important role in fundamental research. In addition, cuprous oxide is commonly used as a pigment, a fungicide, and an antifouling agent for marine paints. It is insoluble in water and organic solvents. This work presents the examinations of the influence of bath, temperature, pH and current density on the characteristics of electrochemically synthesized cuprous oxide. In the 'classic' process of synthesis, which is carried out under galvanostatic conditions on the anode, the grain size of the powder decreases with the increase in current density while the grain colour becomes lighter. The best commercial quality of the Cu2O (grain size, colour, content of choride was obtained at the temperature of 80°C, concentration of NaCl of 3 mol/dm3 and current density of 400 A/m2.

  4. Synthesis and characterization of ruthenium-decorated nanoporous platinum materials

    Peng Xinsheng; Koczkur, Kallum; Chen, Aicheng

    2007-01-01

    We report on the synthesis of novel three-dimensional nanoporous Pt-Ru bimetallic networks by decorating nanoporous Pt networks with Ru using a hydrothermally assisted precipitating process. Scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDS) were used to characterize the morphology and the composition of the nanoporous Pt-Ru networks formed. X-ray diffraction analysis confirmed that, after protected annealing treatment, Pt-Ru bimetallic material was formed. The electrocatalytic activity of the synthesized nanoporous Pt-Ru networks was characterized using electrochemical oxidation of methanol as a probe. The electrocatalytic activity of the nanoporous Pt networks significantly increases with the increments of decorated Ru and reaches the highest value with 41% of Ru. The peak current of methanol oxidation on the nanoporous Pt-Ru(41%) bimetallic networks is over 180% higher than that on the nanoporous Pt networks without Ru decoration. This is very desirable for fuel cell development and electrochemical sensor design

  5. Synthesis and characterization of rhodium sulfide nanoparticles and thin films

    Sosibo, Ndabenhle M.; Revaprasadu, Neerish

    2008-01-01

    The synthesis and characterization of a rhodium complex, [Rh(S 2 CNEt 2 ) 2 ] is described. The complex was thermolysed at a high temperature (280 deg. C) in the presence of capping agent, hexadecylamine (HDA) to form Rh 2 S 3 nanoparticles. Rod-shaped Rh 2 S 3 nanoparticles with an average length of 26.7 nm and an average breadth of 7.8 nm were synthesized. The complex was also used as a single molecule precursor for the deposition of Rh 2 S 3 thin films on a glass substrate at 350 deg. C and 450 deg. C using the Aerosol Assisted Chemical Vapour Deposition (AACVD) technique. The resultant thin films showed temperature dependent morphologies and showed (0 2 2), (4 1 1) and (6 1 1) lattice planes characteristic of to the orthorhombic Rh 2 S 3 phase. X-ray diffraction and scanning electron microscopy techniques were used to characterize the films

  6. Structure, reactivity and synthesis of piramidines and their derivates (dihidroperimidines and perimidinones); Estructura, reactividad y sintesis de perimidinas y de sus derivados (dihidroperimidinas y perimifinonas)

    Claramunt, R.M.; Dotor, J.; Elguero, J. [Departamento de Quimica Organica, Facultad de Ciencias, UNED, Madrid (Spain)

    1995-12-01

    This review reports 346 references dealing with structure, reactivity and synthesis of pyrimidines and their derivatives (mainly 2,3-dihidroperimidines, 2-perimidinones and perimidinium salts). Special emphasis has been made on spectroscopy and structural properties as well as on reactivity. 346 refs.

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

    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.

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

    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

  9. Characterization of Transition Metal Carbide Layers Synthesized by Thermo-reactive Diffusion Processes

    Laursen, Mads Brink; Fernandes, Frederico Augusto Pires; Christiansen, Thomas Lundin

    2015-01-01

    . In this study halide-activated pack cementation techniques were used on tool steel Vanadis 6 and martensitic stainless steel AISI 420 in order to produce hard layers of titanium carbide (TiC), vanadium carbide (V8C7) and chromium carbides (Cr23C6 and Cr7C3). Surface layers were characterized by scanning......Hard wear resistant surface layers of transition metal carbides can be produced by thermo-reactive diffusion processes where interstitial elements from a steel substrate together with external sources of transition metals (Ti, V, Cr etc.) form hard carbide and/or nitride layers at the steel surface...... electron microscopy, X-ray diffraction and Vickers hardness testing. The study shows that porosityfree, homogenous and very hard surface layers can be produced by thermo-reactive diffusion processes. The carbon availability of the substrate influences thickness of obtained layers, as Vanadis 6 tool steel...

  10. BDNF Val66Met polymorphism is associated with HPA axis reactivity to psychological stress characterized by genotype and gender interactions.

    Shalev, Idan; Lerer, Elad; Israel, Salomon; Uzefovsky, Florina; Gritsenko, Inga; Mankuta, David; Ebstein, Richard P; Kaitz, Marsha

    2009-04-01

    A key protein in maintaining neuronal integrity throughout the life span is brain-derived neurotrophic factor (BDNF). The BDNF gene is characterized by a functional polymorphism, which has been associated with stress-related disorders such as anxiety-related syndromes and depression, prompting us to examine individual responses by Genotype and Sex to a standardized social stress paradigm. Gender differences in BDNFxstress responses were posited because estrogen induces synthesis of BDNF in several brain regions. 97 university students (51 females and 46 males) participated in a social stress procedure (Trier Social Stress Test, TSST). Indices of stress were derived from repeated measurement of cortisol, blood pressure, and heart rate during the TSST. All subjects were genotyped for the Val66Met polymorphism. Tests of within-subject effects showed a significant three-way interaction (SPSS GLM repeated measures: Time (eight levels)xBDNF (val/val, val/met)xSex: p=0.0002), which reflects gender differences in the pattern of cortisol rise and decline during the social challenge. In male subjects, val/val homozygotes showed a greater rise in salivary cortisol than val/met heterozygotes. In female subjects, there was a trend for the opposite response, which is significant when area under the curve increase (AUCi) was calculated for the val/val homozygotes to show the lowest rise. Overall, the same pattern of results was observed for blood pressure and heart rate. These results indicate that a common, functionally significant polymorphism in the BDNF gene modulates HPA axis reactivity and regulation during the TSST differently in men and women. Findings may be related to gender differences in reactivity and vulnerability to social stress.

  11. Insitu synthesis of self-assembled gold nanoparticles on glass or silicon substrates through reactive inkjet printing

    Abulikemu, Mutalifu

    2013-12-18

    A facile and low cost method for the synthesis of self-assembled nanoparticles (NPs) with minimal size variation and chemical waste by using reactive inkjet printing was developed. Gold NPs with diameters as small as (8±2)nm can be made at low temperature (120 °C). The size of the resulting NPs can be readily controlled through the concentration of the gold precursor and oleylamine ink. The pure gold composition of the synthesized NPs was confirmed by energy-dispersive X-ray spectroscopy (EDXS) analysis. High-resolution SEM (HRSEM) and TEM (HRTEM), and X-ray diffraction revealed their size and face-centered cubic (fcc) crystal structure, respectively. Owing to the high density of the NP film, UV/Vis spectroscopy showed a red shift in the intrinsic plasmonic resonance peak. We envision the extension of this approach to the synthesis of other nanomaterials and the production of tailored functional nanomaterials and devices. Midas touch: The use of low-cost manufacturing approaches in the synthesis of nanoparticles is critical for many applications. Reactive inkjet printing, along with a judicious choice of precursor/solvent system, was used to synthesize a relatively uniform assembly of crystalline gold nanoparticles, with diameters as small as (8±2)nm, over a given substrate surface. © 2014 WILEY-VCH Verlag GmbH.

  12. One-pot synthesis and electrochemical reactivity of carbon coated LiFePO4 spindles

    Yu Juanjuan; Hu Juncheng; Li Jinlin

    2012-01-01

    Highlights: ► Carbon coated LiFePO 4 spindles have been successfully synthesized via a novel supercritical method. ► The concentrations of lithium have an effect on the morphology of carbon coated LiFePO 4 . ► Amorphous carbon layer formed on the surface of LiFePO 4 by adding glucose. ► The carbon coating is responsible for the enhanced electrochemical performance. - Abstract: Spindle-like carbon coated LiFePO 4 (LiFePO 4 /C) composites have been successfully synthesized via a novel one-pot supercritical methanol method. The products were characterized by X-ray power diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS) and thermogravimetric analysis (TGA). The particle size, morphology and electrochemical reactivity changed with the concentration of lithium and carbon source. A possible morphology evolution process was also proposed. The glucose not only facilitates the formation of single crystalline LiFePO 4 , but also gives an amorphous carbon layer on the surface LiFePO 4 spindles.

  13. Synthesis, characterization and antimicrobial activity of important heterocyclic acrylic copolymers

    2008-10-01

    Full Text Available The acrylate monomer, 7-acryloyloxy-4-methyl coumarin (AMC has been synthesized by reacting 7-hydroxy-4-methyl coumarin, with acryloyl chloride in the presence of NaOH at 0–5°C. Copolymers of 7-acryloyloxy-4-methyl coumarin (AMC with vinyl acetate (VAc were synthesized in DMF (dimethyl formamide solution at 70±1°C using 2,2′-azobisisobutyronitrile (AIBN as an initiator with different monomer-to-monomer ratios in the feed. The copolymers were characterized by Fourier transform infra red (FTIR spectroscopy. The copolymer composition was evaluated by 1H-NMR (proton nuclear magnetic resonance and was further used to determine reactivity ratios. The monomer reactivity ratios for AMC (M1-VAc (M2 pair were determined by the application of conventional linearization methods such as Fineman-Ross (r1 = 0.6924; r2 = 0.6431, Kelen-Tüdõs (r1 = 0.6776; r2 = 0.6374 and extended Kelen-Tüdõs (r1 = 0.6657; r2 = 0.6256. Thermo gravimetric analysis showed that thermal decomposition of the copolymers occurred in single stage in the temperature range of 263–458°C. The molecular weights of the polymers were determined using gel permeation chromatography. The homo and copolymers were tested for their antimicrobial properties against selected microorganisms.

  14. Synthesis and characterization of redox-active ferric nontronite

    Ilgen, A. G.; Kukkadapu, R. K.; Dunphy, D. R.; Artyushkova, K.; Cerrato, J. M.; Kruichak, J. N.; Janish, M. T.; Sun, C. J.; Argo, J. M.; Washington, R. E.

    2017-10-01

    Heterogeneous redox reactions on clay mineral surfaces control mobility and bioavailability of redox-sensitive nutrients and contaminants. Iron (Fe) residing in clay mineral structures can either catalyze or directly participate in redox reactions; however, chemical controls over its reactivity are not fully understood. In our previous work we demonstrated that converting a minor portion of Fe(III) to Fe(II) (partial reduction) in the octahedral sheet of natural Fe-rich clay mineral nontronite (NAu-1) activates its surface, making it redox-active. In this study we produced and characterized synthetic ferric nontronite (SIP), highlighting structural and chemical similarities and differences between this synthetic nontronite and its natural counterpart NAu-1, and probed whether mineral surface is redox-active by reacting it with arsenic As(III) under oxic and anoxic conditions. We demonstrate that synthetic nontronite SIP undergoes the same activation as natural nontronite NAu-1 following the partial reduction treatment. Similar to NAu-1, SIP oxidized As(III) to As(V) under both oxic (catalytic pathway) and anoxic (direct oxidation) conditions. The similar reactivity trends observed for synthetic nontronite and its natural counterpart make SIP an appropriate analog for laboratory studies. The development of chemically pure analogs for ubiquitous soil minerals will allow for systematic research of the fundamental properties of these minerals.

  15. Synthesis, characterization and behaviour of trans-bis (argininate) copper (II) to gamma radiation

    Pereira, A.B.

    1984-01-01

    The synthesis, the characterization and the behaviour to gamma radiation of trans-bis (argininate) copper (II) are presented. The synthesis is made from copper sulfate, sodium hydroxide and hydrochloride of L (+) arginine, in aqueous medium, and the characterization by infrared spectroscopy, visible and ultraviolet spectroscopy and elementary analysis. (C.G.C.)

  16. Synthesis and characterization of related substances of Azilsartan Kamedoxomil

    Maddi N. V. D. Harikiran

    2017-03-01

    Full Text Available Azilsartan Kamedoxomil is an AT1-subtype angiotensin II receptor blocker (ARB. During the laboratory synthesis of Azilsartan Kamedoxomil, four related substances of Azilsartan Kamedoxomil were observed and identified. These were 2-Ethoxy-3-[[4-[2- [4-[(5-methyl-2-oxo-1,3-dioxol-4-ylmethyl]-5-oxo-1,2,4-oxadiazol-3-yl]phenyl]phenyl] methyl] benzimidazole-4-carboxylic acid (azilsartan N-medoxomil, 9, (5-methyl-2-oxo- 1,3-dioxol-4-ylmethyl 2-ethoxy-3-[[4-[2-[4-[(5-methyl-2-oxo-1,3-dioxol-4-ylmethyl]-5- oxo-1,2,4-oxadiazol-3-yl]phenyl]phenyl] methyl] benzimidazole-4-carboxylate (azilsartan dimedoxomil, 10, (5-methyl-2-oxo-1,3-dioxo-4-ylmethyl 1-[2’-(4,5-dihydro-5-oxo-4H- 1,2,4-oxadiazol-3-ylbiphenyl-4-yl]methyl]-2-methoxy-1H-benzimidazole-7-carboxylate (methoxy analogue of azilsartan medoxomil, 11, Methyl 1-((2’-amidobiphenyl-4-yl methyl-2-ethoxy-1H-benzo[d]imidazole-7-carboxylate (amide methyl ester, 12. The present work describes the origin, synthesis and characterization of these related substances.

  17. High temperature bismuth cuprate superconductors synthesis and characterization

    Mansori, M.; Satre, P.; Breandon, C.; Roubin, M.; Sebaoun, A.

    1993-01-01

    High temperature superconductor phases synthesis by coprecipitation in alkaline solution is reported. (Bi 1.6 Pb 0.4 )Sr 2 Ca 1 Cu 2 O 8+x and (Bi 1.6 Pb 0.4 )Sr 2 Ca 2 Cu 3 O 10+y noted (2212) and (2223) have been prepared and studied. From aqueous nitrate solutions of Bi, Pb, Sr, Ca and Cu and oxalic acid aqueous solution as well as ethylene glycol, using an organic base (the triethylamine), the pH was increased up to the path of the precipitation zone (pH = 10.5-11.2). This method assures a good granulometric homogeneity of powders. Thermal analysis and characterization of the different components produced during the synthesis have been studied by DTA (differential thermal analysis)- TGA (thermogravimetric analysis), X-ray diffraction at different temperatures and by Infrared spectroscopy with a Fourier transformation. The measurements of magnetic susceptibility for the 2212 (with and without lead) and 2223 (with lead) phases have permitted us to observe the critical temperatures of 84 K, 87 K and 114 K. (author). 29 refs., 2 figs., 4 tabs

  18. Synthesis and Characterization of Highly Intercalated Graphite Bisulfate

    Salvatore, Marcella; Carotenuto, Gianfranco; De Nicola, Sergio; Camerlingo, Carlo; Ambrogi, Veronica; Carfagna, Cosimo

    2017-03-01

    Different chemical formulations for the synthesis of highly intercalated graphite bisulfate have been tested. In particular, nitric acid, potassium nitrate, potassium dichromate, potassium permanganate, sodium periodate, sodium chlorate, and hydrogen peroxide have been used in this synthesis scheme as the auxiliary reagent (oxidizing agent). In order to evaluate the presence of delamination, and pre-expansion phenomena, and the achieved intercalation degree in the prepared samples, the obtained graphite intercalation compounds have been characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray powder diffraction (XRD), infrared spectroscopy (FT-IR), micro-Raman spectroscopy ( μ-RS), and thermal analysis (TGA). Delamination and pre-expansion phenomena were observed only for nitric acid, sodium chlorate, and hydrogen peroxide, while the presence of strong oxidizers (KMnO4, K2Cr2O7) led to stable graphite intercalation compounds. The largest content of intercalated bisulfate is achieved in the intercalated compounds obtained from NaIO4 and NaClO3.

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

    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.

  20. Antibacterial gold nanoparticles-biomass assisted synthesis and characterization.

    Badwaik, Vivek D; Willis, Chad B; Pender, Dillon S; Paripelly, Rammohan; Shah, Monic; Kherde, Yogesh A; Vangala, Lakshmisri M; Gonzalez, Matthew S; Dakshinamurthy, Rajalingam

    2013-10-01

    Xylose is a natural monosaccharide found in biomass such as straw, pecan shells, cottonseed hulls, and corncobs. Using this monosaccharide, we report the facile, green synthesis and characterization of stable xylose encapsulated gold nanoparticles (Xyl-GNPs) with potent antibacterial activity. Xyl-GNPs were synthesized using the reduction property of xylose in an aqueous solution containing choloraurate anions carried out at room temperature and atmospheric pressure. These nanoparticles were stable and near spherical in shape with an average diameter of 15 +/- 5 nm. Microbiological assay results showed the concentration dependent antibacterial activity of these particles against both Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus epidermidis) bacteria. Thus the facile, environmentally friendly Xyl-GNPs have many potential applications in chemical and biomedical industries, particularly in the development of antibacterial agents in the field of biomedicine.

  1. Synthesis and Characterization of Hydroxyapatite/Fullerenol Nanocomposites.

    Djordjevic, Aleksandar; Ignjatovic, Nenad; Seke, Mariana; Jovic, Danica; Uskokovic, Dragan; Rakocevic, Zlatko

    2015-02-01

    Fullerenols are polyhydroxylated, water soluble derivatives of fullerene C60, with potential application in medicine as diagnostic agents, antioxidants or nano drug carriers. This paper describes synthesis and physical characterization of a new nanocomposite hydroxyapatite/fullerenol. Surface of the nanocomposite hydroxyapatite/fullerenol is inhomogeneous with the diameter of the particles in the range from 100 nm to 350 nm. The ζ potential of this nanocomposite is ten times lower when compared to hydroxyapatite. Surface phosphate groups of hydroxyapatite are prone to forming hydrogen bonds, when in close contact with hydroxyl groups, which could lead to formation of hydrogen bonds between hydroxyapatite and hydroxyl groups of fullerenol. The surface of hydroxyapatite particles (-2.5 mV) was modified by fullerenol particles, as confirmed by the obtained ζ potential value of the nanocomposite biomaterial hydroxyapatite/fullerenol (-25.0 mV). Keywords: Hydroxyapatite, Fullerenol, Nanocomposite, Surface Analysis.

  2. Synthesis and characterization of waterborne polyurethane acrylate copolymers

    Sultan, Misbah; Bhatti, Haq Nawaz; Zuber, Mohammad; Barikani, Mehdi

    2013-01-01

    Polyurethane acrylate copolymers were synthesized by emulsion polymerization process. To reduce the environmental hazards, organic solvents were replaced by eco-friendly aqueous system. Concentration of polyurethane and acrylate monomer was varied to investigate the effect of chemical composition on performance properties of copolymers. FTIR spectroscopy was used as a key tool to record the chemical synthesis route. The synthesized copolymer emulsions were characterized by evaluating their particle size, viscosity, dry weight content, chemical and water resistance. Thermal decomposition was studied by thermogravimetric analysis. Scanning electron microscope was used to visualize the morphological structure of copolymers. The experimental results indicate better polyurethane acrylate compatibility till the ratio of 30/70. However, these copolymers exhibited synergistic effects between the two polymers and revealed a remarkable improvement in numerous coating properties

  3. SYNTHESIS AND CHARACTERIZATION OF NEW STABILIZERS WITH OPTIMAL MOLECULAR WEIGHT

    Jiang-qing Pan

    2001-01-01

    Over 2 × l08 tons of polymers are produced every year, and a large portion of polymers faces the degradation problem. There are many effective methods to protect polymers against degradation and the addition of stabilizers to polymer remains the most convenient and effective way of enhancing polymer life and performance. In this article, a series of effective stabilizers with optimal molecular weight (MW), including common, monomeric and polymeric stabilizers (antioxidant and light stabilizer) were synthesized using isocyanation, controlled isocyanation, hydrosilylation, epoxide addition, macroreaction of stabilizing functional compounds and polymerization of monomeric stabilizers. The sructure and performance of these new stabilizers were characterized by using IR, NMR, MS, UV-spectra, XPS and elemental analysis. The current development of stabilizer synthesis was also reviewed.``

  4. Synthesis and characterization of acrylate copolymer containing fluorescein functional group

    Hui, Guodong; Huang, Weiyun; Song, Yunzhao; Chen, Deben; Zhong, Anyong [Sichuan University, Chengdu (China)

    2013-08-15

    We report a novel method to fabricate fluorescent polymer (F-CPA) based on the esterification between acrylate copolymer (CPA) and fluorescein using N, N-dicyclohexylcarbodiimide (DCC)/4-dimethylaminopyridine (DMAP) as catalyst. The resulting copolymer was characterized by Fourier transform-infrared spectroscopy (FT-IR), gel permeation chromatography (GPC), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), ultraviolet-visible spectroscopy (UV-Vis) and fluorescence spectroscopy. In addition, the influences of concentration, solvents, pH and metal cations (Cu{sup 2+}, Fe{sup 3+} and Zn{sup 2+}) on the fluorescent behaviors of F-CPA are discussed in detail. All those observations suggest that the synthesized F-CPA is an excellent luminescent macromolecular material with simple synthesis method and excellent solubility. Moreover, its sensitive fluorescence response behaviors to solvents, pH and metal cations make it to become a polymer-based probe.

  5. Synthesis and characterization of acrylate copolymer containing fluorescein functional group

    Hui, Guodong; Huang, Weiyun; Song, Yunzhao; Chen, Deben; Zhong, Anyong

    2013-01-01

    We report a novel method to fabricate fluorescent polymer (F-CPA) based on the esterification between acrylate copolymer (CPA) and fluorescein using N, N-dicyclohexylcarbodiimide (DCC)/4-dimethylaminopyridine (DMAP) as catalyst. The resulting copolymer was characterized by Fourier transform-infrared spectroscopy (FT-IR), gel permeation chromatography (GPC), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), ultraviolet-visible spectroscopy (UV-Vis) and fluorescence spectroscopy. In addition, the influences of concentration, solvents, pH and metal cations (Cu"2"+, Fe"3"+ and Zn"2"+) on the fluorescent behaviors of F-CPA are discussed in detail. All those observations suggest that the synthesized F-CPA is an excellent luminescent macromolecular material with simple synthesis method and excellent solubility. Moreover, its sensitive fluorescence response behaviors to solvents, pH and metal cations make it to become a polymer-based probe

  6. Synthesis and characterization of new polyamino-cyclodextrin materials.

    Lo Meo, Paolo; D'Anna, Francesca; Gruttadauria, Michelangelo; Riela, Serena; Noto, Renato

    2012-01-10

    With the aim of the synthesis of chemically modified cyclodextrins bearing polyamine pendant groups, potentially useful as capping agents for the preparation of nanosized metal systems or as auxiliaries for gene transfection, the reaction between the heptakis-(6-iodo)-(6-deoxy)-β-cyclodextrin and various polyamines has been explored. This synthetic approach allows obtaining materials constituted by mixtures of cyclodextrins, having different degrees of substitution, which were satisfactorily characterized by means of various complementary techniques (ESI-MS, NMR, potentiometric titration). The products obtained were successfully subjected to preliminary tests for their binding abilities towards suitable organic guests and as capping agents for the preparation of stable silver nanoparticles. Copyright © 2011 Elsevier Ltd. All rights reserved.

  7. Synthesis and characterization of the natural and burned hydrotalcite

    Granados C, F.

    2006-01-01

    The synthesis and the structural and surface properties of the natural and burned hydrotalcite using salts of AlCl 3 and MgCl 2 .6H 2 O its were studied. Its were used those analysis of BET, IR, XRD, TGA and SEM to characterize these materials. The obtained product was identified as the natural or carbonated hydrotalcite of chemical formula Mg 6 Al 2 (OH) 16 CO 3 .4H 2 O. The hydrotalcite was roasted at 500 C during 5 h and the was obtained roasted hydrotalcite (HTC) that is a material of high selectivity toward the anions that it can be efficiently used as adsorbent material in studies of adsorption for the treatment of anionic radioactive waste present in watery solution. (Author)

  8. Synthesis and characterization of oxovanadium (IV) dithiocarbamates with pyridine

    Doadrio, Antonio L.; Sotelo, Jose; Fernandez-Ruano, Ana [Universidad Complutense, Madrid (Spain). Facultad de Farmacia. Dept. de Quimica Inorganica y Bioinorganica]. E-mail: antoniov@farm.ucm.es

    2002-07-01

    We report the synthesis and study of a new series of oxovanadium (IV) dithiocarbamate adducts and derivatives with pyridine and cyclohexyl, di-iso-butyl, di-n-propyl, aniline, morpholine, piperidine and di-iso-propyl amines. The complexes have been characterized by analytical, magneto chemical, IR, visible-UV spectral and thermal studies, and are assigned the formulas [VO(L){sub 2}].py, where L=cyclohexyl, di-iso-butyl, di-n-propyl, aniline dithiocarbamate and [VO(OH)(L)(py){sub 2}] OH.H{sub 2}O (L=morpholine, piperidine and di-iso-propyl dithiocarbamate). The effect of the adduct formation on the p{sub V=0} bound is discussed in terms of the IR (V=O, V-S and V-N stretching frequencies) and electronic spectra (d-d transitions). (author)

  9. Synthesis and Spectroscopic Characterization of Two Tetrasubstituted Cationic Porphyrin Derivatives

    Newton M. Barbosa Neto

    2011-07-01

    Full Text Available An imidazolium tetrasubstituted cationic porphyrin derivative (the free base and its Zn(II complex with five-membered heterocyclic groups in the meso-positions were synthesized using microwave irradiation, and the compounds obtained characterized by 1H-NMR and mass spectrometry. We observed that under microwave irradiation the yield is similar to when the synthesis is performed under conventional heating, however, the time required to prepare the porphyrins decreases enormously. In order to investigate the electronic state of these compounds, we employed UV-Vis and fluorescence spectroscopy combined with quantum chemical calculations. The results reveal the presence, in both compounds, of a large number of electronic states involving the association between the Soret and a blue-shifted band. The Soret band in both compounds also shows a considerable solvent dependence. As for emission, these compounds present low quantum yield at room temperature and no solvent influence on the fluorescence spectra was observed.

  10. Nanoscale Synthesis and Characterization Laboratory Annual Report 2005

    Hamza, A V; Lesuer, D R

    2006-01-03

    The Nanoscale Synthesis and Characterization Laboratory's (NSCL) primary mission is to create and advance interdisciplinary research and development opportunities in nanoscience and technology. The initial emphasis of the NSCL has been on development of scientific solutions in support of target fabrication for the NIF laser and other stockpile stewardship experimental platforms. Particular emphasis has been placed on the design and development of innovative new materials and structures for use in these targets. Projects range from the development of new high strength nanocrystalline alloys to graded density materials to high Z nanoporous structures. The NSCL also has a mission to recruit and train personnel for Lab programs such as the National Ignition Facility (NIF), Defense and Nuclear Technologies (DNT), and Nonproliferation, Arms control and International security (NAI). The NSCL continues to attract talented scientists to the Laboratory.

  11. Synthesis and Characterization of Atomically Precise Copper Nanoclusters

    Nguyen, Thuy-Ai Dang

    isolated from the reaction of Cu(OAc) with Ph2SiH2, in the presence of PPh3. As formulated, [Cu26H 17(PPh3)9(OAc)3] features a magic number N* = 6, which is unprecedented for a copper nanocluster. XANES supports an assignment of more Cu(0) character than [Cu25H 22(PPh3)12]Cl (N* = 2) for this complex. A critical reevaluation of the synthesis and characterization of Cu 8(MPP)4 is reported. This product was reportedly formed by reaction of Cu(NO3)2 with 2-mercapto-5-n-propylpyrimidine (HMPP) and NaBH4, in ethanol, in the presence of [N(C8H 17)4][Br]. However, upon reevaluation, no experimental evidence to support the existence of Cu8(MPP)4 was found. Instead, the material isolated from this reaction is a complex mixture containing [N(C8H17)4]+, Br -, NO3-, 2-mercapto-5-n-propyl-1,6-dihydropyrimidine (H2MPP*), along with the Cu(I) coordination polymer, [Cu(MPP)]n. H2MPP* and [Cu(MPP)]n, as well as the related Cu(I) coordination complexes, [Cu(HMPP*)]n and [Cu2(MPP*)]n are independently synthesized to support these conclusions.

  12. Boron-based nanostructures: Synthesis, functionalization, and characterization

    Bedasso, Eyrusalam Kifyalew

    Boron-based nanostructures have not been explored in detail; however, these structures have the potential to revolutionize many fields including electronics and biomedicine. The research discussed in this dissertation focuses on synthesis, functionalization, and characterization of boron-based zero-dimensional nanostructures (core/shell and nanoparticles) and one-dimensional nanostructures (nanorods). The first project investigates the synthesis and functionalization of boron-based core/shell nanoparticles. Two boron-containing core/shell nanoparticles, namely boron/iron oxide and boron/silica, were synthesized. Initially, boron nanoparticles with a diameter between 10-100 nm were prepared by decomposition of nido-decaborane (B10H14) followed by formation of a core/shell structure. The core/shell structures were prepared using the appropriate precursor, iron source and silica source, for the shell in the presence of boron nanoparticles. The formation of core/shell nanostructures was confirmed using high resolution TEM. Then, the core/shell nanoparticles underwent a surface modification. Boron/iron oxide core/shell nanoparticles were functionalized with oleic acid, citric acid, amine-terminated polyethylene glycol, folic acid, and dopamine, and boron/silica core/shell nanoparticles were modified with 3-(amino propyl) triethoxy silane, 3-(2-aminoethyleamino)propyltrimethoxysilane), citric acid, folic acid, amine-terminated polyethylene glycol, and O-(2-Carboxyethyl)polyethylene glycol. A UV-Vis and ATR-FTIR analysis established the success of surface modification. The cytotoxicity of water-soluble core/shell nanoparticles was studied in triple negative breast cancer cell line MDA-MB-231 and the result showed the compounds are not toxic. The second project highlights optimization of reaction conditions for the synthesis of boron nanorods. This synthesis, done via reduction of boron oxide with molten lithium, was studied to produce boron nanorods without any

  13. Synthesis and reactivity ratios of regioisomeric vinyl-1,2,3-triazoles with styrene

    Lartey, M; Gillissen, M.A.J.; Adzima, B.J.; Takizawa, K.; Luebke, D.R.; Nulwala, H.B.

    2013-01-01

    The free radical reactivity ratios between styrene and different vinyl-1,2,3-triazole regioisomeric monomers in 1,4-dioxane at 65 degrees C have been established using nonlinear least square method. The results obtained for the reactivity ratio between regioisomers show exceptionally different

  14. Growth of ZnO nanowires on polypropylene membrane surface—Characterization and reactivity

    Bojarska, Marta, E-mail: m.bojarska@ichip.pw.edu.pl [Warsaw University of Technology, Faculty of Chemical and Process Engineering, Waryńskiego 1, 00-645 Warsaw (Poland); Lehrstuhl für Technische Chemie II, Universität Duisburg-Essen, Essen 45117 (Germany); Nowak, Bartosz, E-mail: novakbartosz@gmail.com [Warsaw University of Technology, Faculty of Chemical and Process Engineering, Waryńskiego 1, 00-645 Warsaw (Poland); Skowroński, Jarosław, E-mail: jaroslaw.skowronski@itee.radom.pl [Institute for Sustainable Technologies—National Research Institute, Pułaskiego 6/10, 26-600 Radom (Poland); Piątkiewicz, Wojciech, E-mail: w.piatkiewicz@polymemtech.com [Institute for Sustainable Technologies—National Research Institute, Pułaskiego 6/10, 26-600 Radom (Poland); PolymemTech Sp. z o.o., al. Niepodległości 118/90, 02-577 Warsaw (Poland); Gradoń, Leon, E-mail: l.gradon@ichip.pw.edu.pl [Warsaw University of Technology, Faculty of Chemical and Process Engineering, Waryńskiego 1, 00-645 Warsaw (Poland)

    2017-01-01

    Highlights: • ZnO nanowires were grown on a polypropylene microfiltration capillary membrane. • Plasma treatment was used for membrane activation and hydrophilization. • The photocatalytic/antibacterial properties were studied upon light irradiation. • PP/ZnO nanowires membrane show good photocatalytic and antibacterial activity. • We report a new method for obtaining reactive membranes with ZnO nanowires. - Abstract: Need for a new membrane is clearly visible in recent studies, mostly due to the fouling phenomenon. Authors, focused on problem of biofouling caused by microorganisms that are present in water environment. An attempt to form a new membrane with zinc oxide (ZnO) nanowires was made; where plasma treatment was used as a first step of modification followed by chemical bath deposition. Such membrane will exhibit additional reactive properties. ZnO, because of its antibacterial and photocatalytic properties, is more and more often used in commercial applications. The authors used SEM imaging, measurement of the contact angle, XRD and the FT–IR analysis for membrane characterization. Amount of ZnO deposited on membrane surface was also investigated by dithizone method. Photocatalytic properties of such membranes were examined through methylene blue and humic acid degradation in laboratory scale modules with LEDs as either: wide range white or UV light source. Antibacterial and antifouling properties of polypropylene membranes modified with ZnO nanowires were examined through a series of tests involving microorganisms: model gram-positive and −negative bacteria. The obtained results showed that it is possible to modify the membrane surface in such a way, that additional reactive properties will be given. Thus, not only did the membrane become a physical barrier, but also turned out to be a reactive one.

  15. Characterization of Natural Organic Matter in Alluvial Aquifer Sediments: Approaches and Implications for Reactivity

    Fox, P. M.; Nico, P. S.; Hao, Z.; Gilbert, B.; Tfaily, M. M.; Devadoss, J.

    2015-12-01

    Sediment-associated natural organic matter (NOM) is an extremely complex assemblage of organic molecules with a wide range of sizes, functional groups, and structures, which is intricately associated with mineral particles. The chemical nature of NOM may control its' reactivity towards metals, minerals, enzymes, and bacteria. Organic carbon concentrations in subsurface sediments are typically much lower than in surface soils, posing a distinct challenge for characterization. In this study, we investigated NOM associated with shallow alluvial aquifer sediments in a floodplain of the Colorado River. Total organic carbon (TOC) contents in these subsurface sediments are typically around 0.1%, but can range from 0.03% up to approximately 1.5%. Even at the typical TOC values of 0.1%, the mass of sediment-associated OC is approximately 5000 times higher than the mass of dissolved OC, representing a large pool of carbon that may potentially be mobilized or degraded under changing environmental conditions. Sediment-associated OC is much older than both the depositional age of the alluvial sediments and dissolved OC in the groundwater, indicating that the vast majority of NOM was sequestered by the sediment long before it was deposited in the floodplain. We have characterized the sediment-bound NOM from two locations within the floodplain with differing physical and geochemical properties. One location has relatively low organic carbon (mineral association across different biogeochemical regimes and assess the potential reactivity of various NOM pools.

  16. Manganese Silylene Hydride Complexes: Synthesis and Reactivity with Ethylene to Afford Silene Hydride Complexes.

    Price, Jeffrey S; Emslie, David J H; Britten, James F

    2017-05-22

    Reaction of the ethylene hydride complex trans-[(dmpe) 2 MnH(C 2 H 4 )] (1) with Et 2 SiH 2 at 20 °C afforded the silylene hydride [(dmpe) 2 MnH(=SiEt 2 )] (2 a) as the trans-isomer. By contrast, reaction of 1 with Ph 2 SiH 2 at 60 °C afforded [(dmpe) 2 MnH(=SiPh 2 )] (2 b) as a mixture of the cis (major) and trans (minor) isomers, featuring a Mn-H-Si interaction in the former. The reaction to form 2 b also yielded [(dmpe) 2 MnH 2 (SiHPh 2 )] (3 b); [(dmpe) 2 MnH 2 (SiHR 2 )] (R=Et (3 a) and Ph (3 b)) were accessed cleanly by reaction of 2 a and 2 b with H 2 , and the analogous reactions with D 2 afforded [(dmpe) 2 MnD 2 (SiHR 2 )] exclusively. Both 2 a and 2 b engaged in unique reactivity with ethylene, generating the silene hydride complexes cis-[(dmpe) 2 MnH(R 2 Si=CHMe)] (R=Et (4 a), Ph (4 b)). Compounds trans-2 a, cis-2 b, 3 b, and 4 b were crystallographically characterized, and bonding in 2 a, 2 b, 4 a, and 4 b was probed computationally. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Synthesis of tantalum carbide and nitride nanoparticles using a reactive mesoporous template for electrochemical hydrogen evolution

    Alhajri, Nawal Saad; Yoshida, Hiroshi; Anjum, Dalaver H.; Garcia Esparza, Angel T.; Kubota, Jun; Domen, Kazunari; Takanabe, Kazuhiro

    2013-01-01

    Tantalum carbide and nitride nanocrystals were prepared through the reaction of a tantalum precursor with mesoporous graphitic (mpg)-C 3N4. The effects of the reaction temperature, the ratio of the Ta precursor to the reactive template (mpg-C3N4), and the selection of the carrier gas (Ar, N2 and NH3) on the resultant crystal phases and structures were investigated. The produced samples were characterized using powder X-ray diffraction (XRD), CHN elemental analyses, thermogravimetric analyses (TGA), nitrogen sorption, a temperature-programmed reaction with mass spectroscopy (MS), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). The results indicate that the different tantalum phases with cubic structure, TaN, Ta2CN, and TaC, can be formed under a flow of nitrogen when formed at different temperatures. The Ta3N5 phase with a Ta5+ oxidation state was solely obtained at 1023 K under a flow of ammonia, which gasified the C 3N4 template and was confirmed by detecting the decomposed gaseous products via MS. Significantly, the formation of TaC, Ta2CN, and TaN can be controlled by altering the weight ratio of the C 3N4 template relative to the Ta precursor at 1573 K under a flow of nitrogen. The high C3N4/Ta precursor ratio generally resulted in high carbide content rather than a nitride one, consistent with the role of mpg-C3N4 as a carbon source. Electrochemical measurements revealed that the synthesized nanomaterials were consistently able to produce hydrogen under acidic conditions (pH 1). The obtained Tafel slope indicates that the rate-determining step is the Volmer discharge step, which is consistent with adsorbed hydrogen being weakly bound to the surface during electrocatalysis. © 2013 The Royal Society of Chemistry.

  18. Reactivity of a Carbon-Supported Single-Site Molybdenum Dioxo Catalyst for Biodiesel Synthesis

    Mouat, Aidan R.; Lohr, Tracy L.; Wegener, Evan C.; Miller, Jeffrey T.; Delferro, Massimiliano; Stair, Peter C.; Marks, Tobin J.

    2016-08-23

    A single-site molybdenum dioxo catalyst, (Oc)2Mo(=O)2@C, was prepared via direct grafting of MoO2Cl2(dme) (dme = 1,2-dimethoxyethane) on high-surface- area activated carbon. The physicochemical and chemical properties of this catalyst were fully characterized by N2 physisorption, ICP-AES/OES, PXRD, STEM, XPS, XAS, temperature-programmed reduction with H2 (TPR-H2), and temperature-programmed NH3 desorption (TPD-NH3). The single-site nature of the Mo species is corroborated by XPS and TPR-H2 data, and it exhibits the lowest reported MoOx Tmax of reduction reported to date, suggesting a highly reactive MoVI center. (Oc)2Mo(=O)2@C catalyzes the transesterification of a variety of esters and triglycerides with ethanol, exhibiting high activity at moderate temperatures (60-90 °C) and with negligible deactivation. (Oc)2Mo(=O)2@C is resistant to water and can be recycled at least three times with no loss of activity. The transesterification reaction is determined experimentally to be first order in [ethanol] and first order in [Mo] with ΔH = 10.5(8) kcal mol-1 and ΔS = -32(2) eu. The low energy of activation is consistent with the moderate conditions needed to achieve rapid turnover. This highly active carbon-supported single-site molybdenum dioxo species is thus an efficient, robust, and lowcost catalyst with significant potential for transesterification processes.

  19. Synthesis and characterization of silver nanoparticle composite with poly(p-Br-phenylsilane).

    Kim, Myoung-Hee; Lee, Jun; Mo, Soo-Yong; Woo, Hee-Gweon; Yang, Kap Seung; Kim, Bo-Hye; Lee, Byeong-Gweon; Sohn, Honglae

    2012-05-01

    The one-pot synthesis and characterization of silver nanoparticle-poly(p-Br-phenylsilane) composites have been carried out. The conversion of silver(+1) salt to stable silver(0) nanoparticles is promoted by poly(p-Br-phenylsilane), Br-PPS possessing both possible reactive Si-H bonds in the polymer backbone and C-Br bonds in the substituents. The composites were characterized using XRD, TEM, FE-SEM, and solid-state UV-vis analytical techniques. TEM and FE-SEM data show the formation of the composites where large number of silver nanoparticles (less than 30 nm of size) are well dispersed throughout the Br-PPS matrix. XRD patterns are consistent with that for fcc-typed silver. The elemental analysis for Br atom and the polymer solubility confirm that the cleavage of C-Br bond and the Si-Br dative bonding were not occurred appreciably at ambient temperature. Nonetheless, TGA data suggest that some sort of cross-linking was occurred at high temperature. The size and processability of such nanoparticles depend on the ratio of metal to Br-PPS. In the absence of Br-PPS, most of the silver particles undergo macroscopic aggregation, which indicates that the polysilane is necessary for stabilizing the silver nanoparticles.

  20. Synthesis and characterization of the aluminium phosphates modified with ammonium, calcium and molybdenum by hydrothermal method

    Łuczka Kinga

    2016-06-01

    Full Text Available Synthesis and characterization of the aluminum phosphates modified with ammonium, calcium and molybdenum were conducted. The influence of process parameters (reactive pressure and molar ratios in the reaction mixture were studied. The contents of the individual components in the products were in the range of: 10.97–17.31 wt% Al, 2.65–13.32 wt% Ca, 0.70–3.11 wt% Mo, 4.36–8.38 wt% NH3, and 35.12–50.54 wt% P2O5. The materials obtained in the experiments were characterized by various physicochemical parameters. The absorption oil number was in the range from 67 to 89 of oil/100 g of product, the surface area was within the range of 4–76 m2/g, whereas the average particle size of products reached 282–370 nm. The Tafel tests revealed comparable anticorrosive properties of aluminum phosphates modified with ammonium, calcium, molybdenum in comparison with commercial phosphate.

  1. Synthesis by irradiation and mechanism and structural characterization study of high melt strength polypropylene

    Lugao, Ademar Benevolo

    2004-01-01

    Polypropylene molecular structure is made only by linear molecules interacting by weak forces. The resulting PP has very low melt strength (MS). MS is important to make feasible to process PP by all the transformation technologies based on the free expansion of the melt. The aim of this work was to develop a new process to synthesize PP with crosslinks and/or long chain branches, known as High Melt Strength Polypropylene (HMSPP) and to characterize its structure and synthesis mechanism. HMSPP was obtained by the irradiation of PP under a crosslinking (acetylene) atmosphere or inert or oxidative one, followed by thermal treatment for radical recombination and thermal treatment for annihilation of the remaining radicals under reactive or inert atmosphere. The results from rheological characterization showed that the highest levels of MS were obtained by conducting irradiation and thermal treatments under crosslinking atmospheres. The results for the elucidation of reaction mechanism by electron spin resonance (ESR) showed that acetylene irradiation is effective in promoting the creation of double bonds, based on the formation of polyenil radicals. The results of structural unraveling showed that radiation promotes predominantly the degradation of atactic molecules or molecules with atactic defects. These results support the hypothesis of formation of branched PP molecules based on the reaction of those fragments with the double bonds created in the PP molecules. (author)

  2. Neutral, seven-coordinate dioxime complexes of technetium(III): Synthesis and characterization

    Linder, K.E.; Malley, M.F.; Gougoutas, J.Z.; Unger, S.E.; Nunn, A.D.

    1990-01-01

    The tin-capped complexes 99 Tc(oxime) 3 (μ-OH)SnCl 3 [oxime = dimethylglyoxime (DMG) or cyclohexanedione dioxime (CDO)] can be prepared by the reduction of NH 4 TcO 4 with 2 equiv of SnCl 2 in the presence of dioxime and HCl. These tin-capped complexes can be readily converted into a new class of uncapped Tc-dioxime compounds, TcCl(oxime) 3 , by treatment with HCl. This reaction is reversible. Both the tin-capped and uncapped tris(dioxime) complexes can be converted to the previously reported boron-capped Tc-dioxime complexes TcCl(oxime) 3 BR (R = alkyl, OH) by reaction with boronic acids or with boric acid at low pH. All of these complexes [Tc(oxime) 3 (μ-OH)SnCl 3 , TcCl(oxime) 3 , and TcCl(oxime) 3 BR] appear to be neutral, seven-coordinate compounds of technetium(III). They have been characterized by elemental analysis, 1 H NMR and UV/visible spectroscopy, conductivity, and fast atom bombardment mass spectrometry. The synthesis, characterization, and reactivity of these compounds is discussed. The x-ray crystal structure analysis of TcCl(DMG) 3 and an abbreviated structure report on TcCl(DMG) 3 MeB are described. Crystal data for TcCl(DMG) 3 are reported. 23 refs., 6 figs., 5 tabs

  3. Dispersed metal cluster catalysts by design. Synthesis, characterization, structure, and performance

    Arslan, Ilke [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Dixon, David A. [Univ. of Alabama, Tuscaloosa, AL (United States); Gates, Bruce C. [Univ. of California, Davis, CA (United States); Katz, Alexander [Univ. of California, Berkeley, CA (United States)

    2015-09-30

    To understand the class of metal cluster catalysts better and to lay a foundation for the prediction of properties leading to improved catalysts, we have synthesized metal catalysts with well-defined structures and varied the cluster structures and compositions systematically—including the ligands bonded to the metals. These ligands include supports and bulky organics that are being tuned to control both the electron transfer to or from the metal and the accessibility of reactants to influence catalytic properties. We have developed novel syntheses to prepare these well-defined catalysts with atomic-scale control the environment by choice and placement of ligands and applied state-of-the art spectroscopic, microscopic, and computational methods to determine their structures, reactivities, and catalytic properties. The ligands range from nearly flat MgO surfaces to enveloping zeolites to bulky calixarenes to provide controlled coverages of the metal clusters, while also enforcing unprecedented degrees of coordinative unsaturation at the metal site—thereby facilitating bonding and catalysis events at exposed metal atoms. With this wide range of ligand properties and our arsenal of characterization tools, we worked to achieve a deep, fundamental understanding of how to synthesize robust supported and ligand-modified metal clusters with controlled catalytic properties, thereby bridging the gap between active site structure and function in unsupported and supported metal catalysts. We used methods of organometallic and inorganic chemistry combined with surface chemistry for the precise synthesis of metal clusters and nanoparticles, characterizing them at various stages of preparation and under various conditions (including catalytic reaction conditions) and determining their structures and reactivities and how their catalytic properties depend on their compositions and structures. Key characterization methods included IR, NMR, and EXAFS spectroscopies to identify

  4. Tuned apatitic materials: Synthesis, characterization and potential antimicrobial applications

    Fierascu, Irina; Fierascu, Radu Claudiu; Somoghi, Raluca; Ion, Rodica Mariana; Moanta, Adriana; Avramescu, Sorin Marius; Damian, Celina Maria; Ditu, Lia Mara

    2018-04-01

    Inorganic antimicrobial materials can be viable for multiple applications (related to its use for new buildings with special requirements related to microbiological loading, such as hospital buildings and for consolidation of cultural heritage constructions); also the use of substituted hydroxyapatites for protection of stone artefacts against environmental factors (acidic rain) and biodeterioration it's an option to no longer use of toxic substances. This paper presents methods of synthesis and characterization of the material from the point of view of the obtained structures and final applications. The materials were characterized in terms of composition and morphology (using X-ray Diffraction, X-ray Fluorescence, Inductively coupled plasma-atomic emission spectrometry, Fourier Transform Infrared Spectroscopy, X-ray Photoelectron Spectroscopy, Surface area and pore size determination). Antimicrobial activity was tested against filamentous fungi strains and pathogenic bacteria strains, using both spot on lawn qualitative method (on agar medium) and serial microdilution quantitative method (in broth medium). Further, it was evaluated the anti-biofilm activity of the tested samples toward the most important microbial strains implicated in biofilm development, using crystal violet stained biofilms microtiter assay, followed by spectrophotometric quantitative evaluation.

  5. Synthesis and characterization of rhodium sulfide nanoparticles and thin films

    Sosibo, Ndabenhle M. [Department of Chemistry, University of Zululand, Private Bag X1001, KwaDlangezwa 3886 (South Africa); Revaprasadu, Neerish [Department of Chemistry, University of Zululand, Private Bag X1001, KwaDlangezwa 3886 (South Africa)], E-mail: nrevapra@pan.uzulula.za

    2008-05-15

    The synthesis and characterization of a rhodium complex, [Rh(S{sub 2}CNEt{sub 2}){sub 2}] is described. The complex was thermolysed at a high temperature (280 deg. C) in the presence of capping agent, hexadecylamine (HDA) to form Rh{sub 2}S{sub 3} nanoparticles. Rod-shaped Rh{sub 2}S{sub 3} nanoparticles with an average length of 26.7 nm and an average breadth of 7.8 nm were synthesized. The complex was also used as a single molecule precursor for the deposition of Rh{sub 2}S{sub 3} thin films on a glass substrate at 350 deg. C and 450 deg. C using the Aerosol Assisted Chemical Vapour Deposition (AACVD) technique. The resultant thin films showed temperature dependent morphologies and showed (0 2 2), (4 1 1) and (6 1 1) lattice planes characteristic of to the orthorhombic Rh{sub 2}S{sub 3} phase. X-ray diffraction and scanning electron microscopy techniques were used to characterize the films.

  6. Synthesis And Characterization Of Mebrofenin For Hepatobiliary Imaging

    Purwoko; Tamat, Swasono R.; Yunita, Fitri; Kristanti, Eti

    2003-01-01

    Mebrofenin labeled with Technetium-99m is a new radiopharmaceutical having superior and ideal characteristic as a hepatobiliary-imaging agent. The synthesis and characterization of Mebrofenin (3-Bromo-2,4,6-trimethyl acetanilido iminodiacetic acid) as IDA derivative has been carried out involving three steps of reaction i.e. : acetyllization of 2,4,6-Trimethyl aniline to get 2,4,6-trimethyl chloro acetanilide which upon bromination gives the intermediate bromotrimethyl derivative and [mally by nucleophilic substitution this intermediate product with iminodiacetic acid (IDA) gives mebrofenin. The acetylation and bromination reactions were carried out in acetic acid condition while the substitution was carried out by reflux for 5 hours in ethanol and water adjusted at pH 11. The ethanol was then removed under low pressure, and the unreacted compound was removed by filtration. The filtrate was adjusted to pH 2 - 2.5, and the resulting mebrofenin was isolated by filtration and recrystallized 3 times in ethanol. Characterization of the mebrofenin product was performed by observing its melting point (197-l99 o C), ultra violet and infra red spectra as well as mass spectrometric and high performance liquid chromatographic analysis. The results showed that the product was highly pure and the yield was around 20%

  7. On-Surface Synthesis and Characterization of Honeycombene Oligophenylene Macrocycles.

    Chen, Min; Shang, Jian; Wang, Yongfeng; Wu, Kai; Kuttner, Julian; Hilt, Gerhard; Hieringer, Wolfgang; Gottfried, J Michael

    2017-01-24

    We report the on-surface formation and characterization of [30]-honeycombene, a cyclotriacontaphenylene, which consists of 30 phenyl rings (C 180 H 120 ) and has a diameter of 4.0 nm. This shape-persistent, conjugated, and unsubstituted hexagonal hydrocarbon macrocycle was obtained by solvent-free synthesis on a silver (111) single-crystal surface, making solubility-enhancing alkyl side groups unnecessary. Side products include strained macrocycles with square, pentagonal, and heptagonal shape. The molecules were characterized by scanning tunneling microscopy and density functional theory (DFT) calculations. On the Ag(111) surface, the macrocycles act as molecular quantum corrals and lead to the confinement of surface-state electrons inside the central cavity. The energy of the confined surface state correlates with the size of the macrocycle and is well described by a particle-in-the-box model. Tunneling spectroscopy suggests conjugation within the planar rings and reveals influences of self-assembly on the electronic structure. While the adsorbed molecules appear to be approximately planar, the free molecules have nonplanar conformation, according to DFT.

  8. Synthesis and characterization of carbon fibers obtained through plasma techniques

    Valdivia B, M.

    2005-01-01

    The study of carbon, particularly the nano technology is a recent field, the one which has important implications in the science of new materials. It investigation is of great interest for industries producers of ceramic, metallurgy, electronic, energy storage, biomedicine, among others. The diverse application fields are a reason at national as international level, so that many works are focused in the production of nano fibers of carbon. The Thermal plasma applications laboratory (LAPT) of the National Institute of Nuclear Research (ININ), it is carrying out works about carbon nano technology. The present work has as purpose to carry out the synthesis and characterization of the carbon nano fibers which are obtained by electric arch of alternating current (CA) to high frequencies and by a plasma gun of non transferred arch, where are used hydrocarbons like benzene, methane, acetylene like carbon source and ferrocene, nickel, yttrium and cerium oxide like catalysts. For both techniques its were thought about a relationship among hydrocarbon-catalyst that it favored to the nano fibers production. The obtained product of each experiment outlined it was analyzed by transmission electron microscopy (TEM), scanning electron microscopy (SEM) and X-ray diffraction (XRD), analysis with those were obtained pictures and diffraction graphs, which were observed to arrive to one conclusion on the operation conditions, same analysis with those were characterized the tests carried out according to the nano structures formation of carbon. (Author)

  9. Synthesis and characterization of carboxylic acid functionalized silicon nanoparticles

    Shaner, Ted V.

    Silicon nanoparticles are of great interest in a great number of fields. Silicon nanoparticles show great promise particularly in the field of bioimaging. Carboxylic acid functionalized silicon nanoparticles have the ability to covalently bond to biomolecules through the conjugation of the carboxylic acid to an amine functionalized biomolecule. This thesis explores the synthesis of silicon nanoparticles functionalized by both carboxylic acids and alkenes and their carboxylic acid functionality. Also discussed is the characterization of the silicon nanoparticles by the use of x-ray spectroscopy. Finally, the nature of the Si-H bond that is observed on the surface of the silicon nanoparticles will be investigated using photoassisted exciton mediated hydrosilation reactions. The silicon nanoparticles are synthesized from both carboxylic acids and alkenes. However, the lack of solubility of diacids is a significant barrier to carboxylic acid functionalization by a mixture of monoacids and diacids. A synthesis route to overcome this obstacle is to synthesize silicon nanoparticles with terminal vinyl group. This terminal vinyl group is distal to the surface of the silicon nanoparticle. The conversion of the vinyl group to a carboxylic acid is accomplished by oxidative cleavage using ozonolysis. The carboxylic acid functionalized silicon nanoparticles were then successfully conjugated to amine functionalized DNA strand through an n-hydroxy succinimide ester activation step, which promotes the formation of the amide bond. Conjugation was characterized by TEM and polyacrylamide gel electrophoresis (PAGE). The PAGE results show that the silicon nanoparticle conjugates move slower through the polyacrylamide gel, resulting in a significant separation from the nonconjugated DNA. The silicon nanoparticles were then characterized by the use of x-ray absorption near edge spectroscopy (Xanes) and x-ray photoelectron spectroscopy (XPS) to investigate the bonding and chemical

  10. Synthesis and Photophysical Characterizations of Thermal -Stable Naphthalene Benzimidazoles

    Erten Ela, Şule; Özçelik, Serdar; Eren, Ersin

    2011-01-01

    Microwave-assisted synthesis, photophysical and electrochemical properties of thermal-stable naphthalene benzimidazoles and naphthalimides are studied in this paper. Microwave-assisted synthesis of naphthalene benzimidazoles provide higher yields than the conventional thermal synthesis. Comparative photophysical properties of naphthalene benzimidazoles and naphthalimides are revealed that conjugation of electron-donating group onto naphthalimide moiety increases fluorescence ...

  11. Nanocrystalline hydroxyapatite doped with magnesium and zinc: Synthesis and characterization

    Kalita, Samar J. [Department of Mechanical, Materials and Aerospace Engineering, University of Central Florida, Orlando, FL 32816-2450 (United States)]. E-mail: samar@mail.ucf.edu; Bhatt, Himesh A. [Department of Mechanical, Materials and Aerospace Engineering, University of Central Florida, Orlando, FL 32816-2450 (United States)

    2007-05-16

    During recent years, there have been efforts in developing nanocrystalline bioceramics, to enhance their mechanical and biological properties for use in tissue engineering applications. In this research, we made an attempt to synthesize nanocrystalline bioactive hydroxyapatite (Ca{sub 10}(PO{sub 4}){sub 6}(OH){sub 2}, HAp) ceramic powder in the lower-end of nano-range (2-10 nm), using a simple low-temperature sol-gel technique and studied its densification behavior. We further studied the effects of metal ion dopants during synthesis on powder morphology, and the properties of the sintered structures. Calcium nitrate and triethyl phosphite were used as precursors for calcium and phosphorous, respectively, for sol-gel synthesis. Calculated quantities of magnesium oxide and zinc oxide were incorporated as dopants into amorphous dried powder, prior to calcination at 250-550 {sup o}C. The synthesized powders were analyzed for their phases using X-ray diffraction technique and characterized for powder morphology and particle size using transmission electron microscopy (TEM). TEM analysis showed that the average particle size of the synthesized powders were in the range of 2-10 nm. The synthesized nano-powders were uniaxially compacted and then sintered at 1250 {sup o}C and 1300 {sup o}C for 6 h, separately, in air. A maximum average sintered density of 3.29 g/cm{sup 3} was achieved in structures sintered at 1300 {sup o}C, developed from nano-powder doped with magnesium. Vickers hardness testing was performed to determine the hardness of the sintered structures. Uniaxial compression tests were performed to evaluate the mechanical properties. Bioactivity and biodegradation behavior of the sintered structures were assessed in simulated body fluid (SBF) and maintained in a dynamic state.

  12. Synthesis and characterization of functionalized methacrylates for coatings and biomedical applications

    Shemper, Bianca Sadicoff

    The research presented in this dissertation involves the design of polymers for biomaterials and for coatings applications. The development of non-wettable, hard UV-curing, or reactive coatings is discussed. The biomaterials section involves the syntheses of linear and star-like polymers of the functionalized monomer poly(propylene glycol) monomethacrylate (PPGM) via atom transfer radical polymerization (ATRP) (Chapter II). Its copolymerization with a perfluoroalkyl ethyl methacrylate monomer (1H,1H,2H,2H-heptadecafluorodecyl methacrylate) and the syntheses of linear and star-like amphiphilic copolymers containing the fluorinated monomer and poly(ethyleneglycol) methyl ether methacrylate (MPEGMA) are discussed in Chapter III. The four-arm amphiphilic block copolymer obtained showed unique associative properties leading to micellization in selective solvents. Chapter IV includes research involving the design of films with low surface energy by incorporating fluorine into the polymer. The synthesis, characterization and polymerization of a perfluoroalkylether-substituted methacrylic acid (C8F7) are discussed, and the properties of coatings obtained after its photopolymerization on different substrates are evaluated to confirm formation of low-surface energy polymeric coatings. Subsequently, hard coatings based on methyl (alpha-hydroxymethyl)acrylate (MHMA) were prepared via photopolymerization using UV-light. Firstly, mechanistic investigations into the photopolymerization behavior of (alpha-hydroxymethyl)acrylates (RHMA's) are reported (Chapter V). RHMA derivatives were photopolymerized with various multifunctional acrylates and methacrylates and the effect of crosslinker type and degree of functionality on photopolymerization rates and conversions was investigated. Then, in Chapter VI the synthesis of a series of new crosslinkers is described and their photopolymerization kinetics was investigated in bulk. The effect of these novel crosslinkers on the

  13. Synthesis and characterization of poly iodine anilines by plasma

    Enriquez P, M.A.

    2003-01-01

    The polymers and organic materials present a numberless quantity of applications. However, it has not been but until recent times that it has been found that some of these materials can possess semiconductor properties. This has generated a great interest for the investigation in the area of semiconductor polymers. The poly aniline (Pan) it is one of the main semiconductor polymers because their electric properties change depending on the doping and of the state of oxidation to the one the molecules are subjected. The synthesis of this material has been carried out by means of chemical oxidation or electrochemistry. In this work a study is presented on the formation of poly aniline polymers with halogens chemically united to the aniline ring, poly(m-iodine aniline) (m-PAnI) and poly(m-chloroaniline) (m-PAnCI) for plasma. The plasma is generated by means of discharges of splendor with an r f amplifier to 13.5 MHz to drops pressures (10 -2 mbar). The synthesized polymers were obtained in form of thin film in the walls of the reactor and in the substrate introduced in the one. The electric properties of the polymers were evaluated in function of the time of reaction. Also, the conductivity of the polymers was compared synthesized in this work with reported data of synthesized poly aniline and doped with iodine for plasma. The highest values in conductivity are obtained in the poly aniline where the halogens are chemically connected to the ring that if it is doped with iodine. The atomic proportion in the surface of the polymers was analyzed by dispersive energy spectroscopy with which is deduced that the halogens come off of the molecules of the monomers or of the polymer in formation and that the atoms of iodine get lost more easily than those of chlorine. Other techniques that were used to characterize to the poly aniline were scanning electron microscopy, infrared spectroscopy, thermal gravimetric analysis and X-ray diffraction. The results are presented in

  14. Acrolein stimulates the synthesis of IL-6 and C-reactive protein (CRP) in thrombosis model mice and cultured cells.

    Saiki, Ryotaro; Hayashi, Daisuke; Ikuo, Yukiko; Nishimura, Kazuhiro; Ishii, Itsuko; Kobayashi, Kaoru; Chiba, Kan; Toida, Toshihiko; Kashiwagi, Keiko; Igarashi, Kazuei

    2013-12-01

    Measurements of protein-conjugated acrolein (PC-Acro), IL-6, and C-reactive protein (CRP) in plasma were useful for identifying silent brain infarction with high sensitivity and specificity. The aim of this study was to determine whether acrolein causes increased production of IL-6 and CRP in thrombosis model mice and cultured cells. In mice with photochemically induced thrombosis, acrolein produced at the locus of infarction increased the level of IL-6 and then CRP in plasma. This was confirmed in cell culture systems - acrolein stimulated the production of IL-6 in mouse neuroblastoma Neuro-2a cells, mouse macrophage-like J774.1 cells, and human umbilical vein endothelial cells (HUVEC), and IL-6 in turn stimulated the production of CRP in human hepatocarcinoma cells. The level of IL-6 mRNA was increased by acrolein through an increase in phosphorylation of the transcription factors, c-Jun, and NF-κB p65. Furthermore, CRP stimulated IL-6 production in mouse macrophage-like J774.1 cells and HUVEC. IL-6 functioned as a protective factor against acrolein toxicity in Neuro-2a cells and HUVEC. These results show that acrolein stimulates the synthesis of IL-6 and CRP, which function as protecting factors against acrolein toxicity, and that the combined measurement of PC-Acro, IL-6, and CRP is effective for identification of silent brain infarction. The combined measurements of protein-conjugated acrolein (PC-Acro), IL-6, and C-reactive protein (CRP) in plasma were useful for identifying silent brain infarction. The aim of this study was to determine whether acrolein causes increased production of IL-6 and CRP, and indeed acrolein increased IL-6 synthesis and IL-6 in turn increased CRP synthesis. Furthermore, IL-6 decreased acrolein toxicity in several cell lines. © 2013 International Society for Neurochemistry.

  15. Synthesis and characterization of polycaprolactone for anterior cruciate ligament regeneration

    Gurlek, Ayse Cansu; Sevinc, Burcu; Bayrak, Ece; Erisken, Cevat

    2017-01-01

    Anterior cruciate ligament (ACL) is the most frequently torn ligament in the knee, and complete healing is unlikely due to lack of vascularization. Current approaches for the treatment of ACL injuries include surgical interventions and grafting, however recent reports show that surgeries have 94% recurrency, and that repaired tissues are biomechanically inferior to the native tissue. These necessitate the need for new strategies for scar-free repair/regeneration of ACL injuries. Polycaprolactone (PCL) is a biodegradable and biocompatible synthetic polymer, which has been widely used in the connective tissue repair/regeneration attempts. Here, we report on the synthesis of PCL via ring opening polymerization using ε-caprolactone as the monomer, and ammonium heptamolybdate as a catalyst. The synthesized PCL was characterized using Fourier Transform Infrared Spectroscopy (FTIR) and Nuclear Magnetic Resonance (NMR) spectroscopy. It was then processed using electrospinning to form nanofiber-based scaffolds. These scaffolds were characterized in terms of surface as well as mechanical properties, and compared to the properties of commercially available PCL, and of native ACL tissue harvested from sheep. In addition, scaffolds fabricated with synthesized PCL were evaluated regarding their cell attachment capacity using human bone marrow mesenchymal stem cells (hBMSCs). Our findings demonstrated that the synthesized PCL is similar to its commercially available counterpart in terms of surface morphology and mechanical properties. In addition, fibrous scaffolds generated with electrospinning showed weaker mechanical properties visa vis native ACL tissue in terms of ultimate stress, and elastic modulus. Also, the synthesized PCL can accommodate cell attachment when tested with hBMSCs. Putting together, these observations reveal that the PCL synthesized in this study could be a good candidate as a biomaterial for ligament repair or regeneration. - Highlights: • Synthesis of

  16. Synthesis and characterization of polycaprolactone for anterior cruciate ligament regeneration

    Gurlek, Ayse Cansu; Sevinc, Burcu; Bayrak, Ece; Erisken, Cevat, E-mail: cerisken@etu.edu.tr

    2017-02-01

    Anterior cruciate ligament (ACL) is the most frequently torn ligament in the knee, and complete healing is unlikely due to lack of vascularization. Current approaches for the treatment of ACL injuries include surgical interventions and grafting, however recent reports show that surgeries have 94% recurrency, and that repaired tissues are biomechanically inferior to the native tissue. These necessitate the need for new strategies for scar-free repair/regeneration of ACL injuries. Polycaprolactone (PCL) is a biodegradable and biocompatible synthetic polymer, which has been widely used in the connective tissue repair/regeneration attempts. Here, we report on the synthesis of PCL via ring opening polymerization using ε-caprolactone as the monomer, and ammonium heptamolybdate as a catalyst. The synthesized PCL was characterized using Fourier Transform Infrared Spectroscopy (FTIR) and Nuclear Magnetic Resonance (NMR) spectroscopy. It was then processed using electrospinning to form nanofiber-based scaffolds. These scaffolds were characterized in terms of surface as well as mechanical properties, and compared to the properties of commercially available PCL, and of native ACL tissue harvested from sheep. In addition, scaffolds fabricated with synthesized PCL were evaluated regarding their cell attachment capacity using human bone marrow mesenchymal stem cells (hBMSCs). Our findings demonstrated that the synthesized PCL is similar to its commercially available counterpart in terms of surface morphology and mechanical properties. In addition, fibrous scaffolds generated with electrospinning showed weaker mechanical properties visa vis native ACL tissue in terms of ultimate stress, and elastic modulus. Also, the synthesized PCL can accommodate cell attachment when tested with hBMSCs. Putting together, these observations reveal that the PCL synthesized in this study could be a good candidate as a biomaterial for ligament repair or regeneration. - Highlights: • Synthesis of

  17. Chemically Modified Starch; Allyl- and Epoxy-Starch Derivatives: Their Synthesis and Characterization

    Franssen, M.C.R.; Boeriu, C.

    2014-01-01

    Both native and modified starches, such as starch that is pregelatinized, extruded, acid-converted, cross-linked, and substituted, are widely used in industry. This chapter describes a mild two-step process for the synthesis of novel, highly reactive granular epoxy-starch derivatives. Via this

  18. Characterization and re-activation of oxygen sensors for use in liquid lead-bismuth

    Kurata, Yuji; Abe, Yuji; Futakawa, Masatoshi; Oigawa, Hiroyuki

    2010-01-01

    Control of oxygen concentration in liquid lead-bismuth is one of the most important tasks to develop accelerator driven systems. In order to improve the reliability of oxygen sensors, re-activation treatments were investigated as well as characterization of oxygen sensors for use in liquid lead-bismuth. The oxygen sensor with a solid electrolyte of yttria-stabilized zirconia and a Pt/gas reference electrode showed almost the same electromotive force values in gas and liquid lead-bismuth, respectively, as the theoretical ones at temperatures above 400 deg. C or 450 deg. C. After long-term use of 6500 h, the outputs of the sensor became incorrect in liquid lead-bismuth. The state of the sensor that indicated incorrect outputs could not be recovered by cleaning with a nitric acid. However, it was found that the oxygen sensor became a correct sensor indicating theoretical values in liquid lead-bismuth after re-activation by the Pt-treatment of the outer surface of the sensor.

  19. A transparent Pyrex μ-reactor for combined in situ optical characterization and photocatalytic reactivity measurements

    Dionigi, F.; Hansen, O.; Nielsen, M. G.; Chorkendorff, I.; Vesborg, P. C. K.; Pedersen, T.

    2013-01-01

    A new Pyrex-based μ-reactor for photocatalytic and optical characterization experiments is presented. The reactor chamber and gas channels are microfabricated in a thin poly-silicon coated Pyrex chip that is sealed with a Pyrex lid by anodic bonding. The device is transparent to light in the UV-vis-near infrared range of wavelengths (photon energies between ∼0.4 and ∼4.1 eV). The absorbance of a photocatalytic film obtained with a light transmission measurement during a photocatalytic reaction is presented as a proof of concept of a photocatalytic reactivity measurement combined with in situ optical characterization. Diffuse reflectance measurements of highly scattering photocatalytic nanopowders in a sealed Pyrex μ-reactor are also possible using an integrating sphere as shown in this work. These experiments prove that a photocatalyst can be characterized with optical techniques after a photocatalytic reaction without removing the material from the reactor. The catalyst deposited in the cylindrical reactor chamber can be illuminated from both top and bottom sides and an example of application of top and bottom illumination is presented

  20. Synthesis, Characterization and Optical Constants of Silicon Oxycarbide

    Memon Faisal Ahmed

    2017-01-01

    Full Text Available High refractive index glasses are preferred in integrated photonics applications to realize higher integration scale of passive devices. With a refractive index that can be tuned between SiO2 (1.45 and a-SiC (3.2, silicon oxycarbide SiOC offers this flexibility. In the present work, silicon oxycarbide thin films from 0.1 – 2.0 μm thickness are synthesized by reactive radio frequency magnetron sputtering a silicon carbide SiC target in a controlled argon and oxygen environment. The refractive index n and material extinction coefficient k of the silicon oxycarbide films are acquired with variable angle spectroscopic ellipsometry over the UV-Vis-NIR wavelength range. Keeping argon and oxygen gases in the constant ratio, the refractive index n is found in the range from 1.41 to 1.93 at 600 nm which is almost linearly dependent on RF power of sputtering. The material extinction coefficient k has been estimated to be less than 10-4 for the deposited silicon oxycarbide films in the visible and near-infrared wavelength regions. Morphological and structural characterizations with SEM and XRD confirms the amorphous phase of the SiOC films.

  1. Reactive ion beam etching for microcavity surface emitting laser fabrication: technology and damage characterization

    Matsutani, A.; Tadokoro, T.; Koyama, F.; Iga, K.

    1993-01-01

    Reactive ion beam etching (RIBE) is an effective dry etching technique for the fabrication of micro-sized surface emitting (SE) lasers and optoelectronic devices. In this chapter, some etching characteristics for GaAs, InP and GaInAsP with a Cl 2 gas using an RIBE system are discussed. Micro-sized circular mesas including GaInAsP/InP multilayers with vertical sidewalls were fabricated. RIBE-induced damage in InP substrates was estimated by C-V and PL measurement. In addition, the removal of the induced damage by the second RIBE with different conditions for the InP wafer was proposed. The sidewall damage is characterized by photoluminescence emitted from the etched sidewall of a GaInAsP/InP DH wafer. (orig.)

  2. Detailed characterizations of a Comparative Reactivity Method (CRM) instrument: experiments vs. modelling

    Michoud, V.; Hansen, R. F.; Locoge, N.; Stevens, P. S.; Dusanter, S.

    2015-04-01

    The Hydroxyl radical (OH) is an important oxidant in the daytime troposphere that controls the lifetime of most trace gases, whose oxidation leads to the formation of harmful secondary pollutants such as ozone (O3) and Secondary Organic Aerosols (SOA). In spite of the importance of OH, uncertainties remain concerning its atmospheric budget and integrated measurements of the total sink of OH can help reducing these uncertainties. In this context, several methods have been developed to measure the first-order loss rate of ambient OH, called total OH reactivity. Among these techniques, the Comparative Reactivity Method (CRM) is promising and has already been widely used in the field and in atmospheric simulation chambers. This technique relies on monitoring competitive OH reactions between a reference molecule (pyrrole) and compounds present in ambient air inside a sampling reactor. However, artefacts and interferences exist for this method and a thorough characterization of the CRM technique is needed. In this study, we present a detailed characterization of a CRM instrument, assessing the corrections that need to be applied on ambient measurements. The main corrections are, in the order of their integration in the data processing: (1) a correction for a change in relative humidity between zero air and ambient air, (2) a correction for the formation of spurious OH when artificially produced HO2 react with NO in the sampling reactor, and (3) a correction for a deviation from pseudo first-order kinetics. The dependences of these artefacts to various measurable parameters, such as the pyrrole-to-OH ratio or the bimolecular reaction rate constants of ambient trace gases with OH are also studied. From these dependences, parameterizations are proposed to correct the OH reactivity measurements from the abovementioned artefacts. A comparison of experimental and simulation results is then discussed. The simulations were performed using a 0-D box model including either (1) a

  3. Synthesis, Characterization and Application of Multiscale Porous Materials

    Hussami, Linda

    2010-07-01

    This thesis work brings fresh insights and improved understanding of nano scale materials through introducing new hybrid composites, 2D hexagonal in MCM-41 and 3D random interconnected structures of different materials, and application relevance for developing fields of science, such as fuel cells and solar cells. New types of porous materials and organometallic crystals have been prepared and characterized in detail. The porous materials have been used in several studies: as hosts to encapsulate metal-organic complexes; as catalyst supports and electrode materials in devices for alternative energy production. The utility of the new porous materials arises from their unique structural and surface chemical characteristics as demonstrated here using various experimental and theoretical approaches. New single crystal structures and arene-ligand exchange properties of f-block elements coordinated to ligand arene and halogallates are described in Paper I. These compounds have been incorporated into ordered 2D-hexagonal MCM-41 and polyhedral silica nano foam (PNF-SiO{sub 2}) matrices without significant change to the original porous architectures as described in Paper II and III. The resulting inorganic/organic hybrids exhibited enhanced luminescence activity relative to the pure crystalline complexes. A series of novel polyhedral carbon nano foams (PNF-C's) and inverse foams were prepared by nano casting from PNF-SiO{sub 2}'s. These are discussed in Paper IV. The synthesis conditions of PNF-C's were systematically varied as a function of the filling ratio of carbon precursor and their structures compared using various characterization methods. The carbonaceous porous materials were further tested in Paper V and VI as possible catalysts and catalyst supports in counter- and working electrodes for solar- and fuel cell applications

  4. Synthesis, characterization and in vivo evaluation of biocompatible ferrogels

    Lopez-Lopez, M.T., E-mail: modesto@ugr.es [Department of Applied Physics, University of Granada, Granada (Spain); Instituto de Investigación Biosanitaria ibs.GRANADA, Granada (Spain); Rodriguez, I.A. [Instituto de Investigación Biosanitaria ibs.GRANADA, Granada (Spain); Department of Histology (Tissue Engineering Group), University of Granada, Granada (Spain); Rodriguez-Arco, L. [Department of Applied Physics, University of Granada, Granada (Spain); Instituto de Investigación Biosanitaria ibs.GRANADA, Granada (Spain); Carriel, V. [Instituto de Investigación Biosanitaria ibs.GRANADA, Granada (Spain); Department of Histology (Tissue Engineering Group), University of Granada, Granada (Spain); Bonhome-Espinosa, A.B. [Department of Applied Physics, University of Granada, Granada (Spain); Instituto de Investigación Biosanitaria ibs.GRANADA, Granada (Spain); Campos, F. [Instituto de Investigación Biosanitaria ibs.GRANADA, Granada (Spain); Department of Histology (Tissue Engineering Group), University of Granada, Granada (Spain); Zubarev, A. [Department of Mathematical Physics, Ural Federal University, Ekaterinburg (Russian Federation); Duran, J.D.G. [Department of Applied Physics, University of Granada, Granada (Spain); Instituto de Investigación Biosanitaria ibs.GRANADA, Granada (Spain)

    2017-06-01

    A hydrogel is a 3-D network of polymer chains in which water is the dispersion medium. Hydrogels have found extensive applications in the biomedical field due to their resemblance to living tissues. Furthermore, hydrogels can be endowed with exceptional properties by addition of synthetic materials. For example, magnetic field-sensitive gels, called ferrogels, are obtained by embedding magnetic particles in the polymer network. Novel living tissues with unique magnetic field-sensitive properties were recently prepared by 3-D cell culture in biocompatible ferrogels. This paper critically reviews the most recent progress and perspectives in their synthesis, characterization and biocompatibility evaluation. Optimization of ferrogels for this novel application requires low-density, strongly magnetic, multi-domain particles. Interestingly, the rheological properties of the resulting ferrogels in the absence of field were largely enhanced with respect to nonmagnetic hydrogels, which can only be explained by the additional cross-linking imparted by the embedded magnetic particles. Remarkably, rheological measurements under an applied magnetic field demonstrated that ferrogels presented reversibly tunable mechanical properties, which constitutes a unique advantage with respect to nonmagnetic hydrogels. In vivo evaluation of ferrogels showed good biocompatibility, with only some local inflammatory response, and no particle migration or damage to distant organs.

  5. Synthesis and characterization of tricalcium phosphate ceramics doped with zinc

    Kai, K.C.; Marchi, J.; Ussui, V.; Bressiani, A.H.A.

    2011-01-01

    Due to its biocompatibility, the tricalcium phosphate (TCP) is used as a biomaterial for bone replacement and reconstruction. Zinc (Zn) can replace calcium in the crystal structure of TCP to be added in small quantities, can result in stimulatory effects on bone formation in vitro and in vivo. In this work, pure TCP and Zn-TCP, with general formula (Ca_1_-_xZn_x)_3 (PO_4)_2 and 0 ≤ x ≤ 0.0225, were prepared by wet synthesis, from precursors Ca(OH)_2, H_3PO_4 and ZnO, after calcinated at 800 deg C and characterized by X-ray diffraction, specific surface area, agglomerate size distribution, differential thermal analysis and scanning electron microscopy. The results showed that the addition of small amounts of Zn resulted in TCP with suitable densification and higher specific surface area, may be promising as biomaterial due to the stimulatory effects of zinc associated with suitable mechanical properties of the final material. (author)

  6. Individualized Pixel Synthesis and Characterization of Combinatorial Materials Chips

    Xiao-Dong Xiang

    2015-06-01

    Full Text Available Conventionally, an experimentally determined phase diagram requires studies of phase formation at a range of temperatures for each composition, which takes years of effort from multiple research groups. Combinatorial materials chip technology, featuring high-throughput synthesis and characterization, is able to determine the phase diagram of an entire composition spread of a binary or ternary system at a single temperature on one materials library, which, though significantly increasing efficiency, still requires many libraries processed at a series of temperatures in order to complete a phase diagram. In this paper, we propose a “one-chip method” to construct a complete phase diagram by individually synthesizing each pixel step by step with a progressive pulse of energy to heat at different temperatures while monitoring the phase evolution on the pixel in situ in real time. Repeating this process pixel by pixel throughout the whole chip allows the entire binary or ternary phase diagram to be mapped on one chip in a single experiment. The feasibility of this methodology is demonstrated in a study of a Ge-Sb-Te ternary alloy system, on which the amorphous-crystalline phase boundary is determined.

  7. Synthesis and thermal characterization of xylan-graft-polyacrylonitrile.

    Ünlü, Cüneyt H; Öztekin, N Simge; Atıcı, Oya Galioğlu

    2012-10-01

    In this study emulsion polymerization of acrylonitrile using xylan from agricultural waste material (corn cob) and cerium ammonium nitrate was investigated in terms of catalyst acid. Stock ceric solutions were prepared using either nitric or perchloric acid as catalyst. Optimum conditions were determined using different parameters such as reaction time, temperature, and component concentrations. Nitric acid catalyzed reactions resulted in maximum conversion ratio (96%) at 50°C, 1 h where ceric ion, acrylonitrile, xylan, and catalyst concentrations were 21.7 mmol l(-1), 0.5 mol l(-1), 0.2% (w/v), and 0.1 mol l(-1), respectively. However, 83% conversion was obtained with perchloric acid catalysis at 27 °C, 1 h where concentrations were 5.4 mmol l(-1), 0.8 mol l(-1), 0.5% (w/v), and 0.2 mol l(-1), respectively. Copolymer synthesis using perchloric acid was realized at milder conditions than using nitric acid. Thermal analyses of obtained polymers were conducted to characterize copolymers. Results showed that calculated activation energy, maximum degradation temperature, and heat of thermal decomposition changed relying mainly on molecular weight. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. Synthesis and characterization of metal soaps of lanthanides (III)

    Payolla, Filipe Boccato; Ribeiro, Sidney Jose Lima; Massbni, Antonio Carlos

    2015-01-01

    The present study describes synthesis and partial characterization of Eu"3"+, Nd"3"+, Dy"3"+, Tb"3"+ and Yb"3"+ behenate complexes. The compounds were analyzed using IR-Spectroscopy, TG-DTG, DSC, elemental analysis, XRD, luminescence and SEM. The results show the purity of the compounds. The XRD analysis and the SEM images show the high crystallinity of the complexes. TG-DTG and DSC analyses do not show a liquid crystal behavior, as occurs with other lanthanide metallic soaps. The mass loses until 1000° C show that the compounds lose ligand fragments at specific temperatures. XRD of the residues are compatible with the respective lanthanide oxides. The luminescence analysis shows that the Eu"3"+, Nd"3"+ and Tb"3"+ complexes presents appreciable emission. The Judd-Ofelt parameters obtained are compatible with the values found in the literature. It was not possible to obtain the complexes in a glass-form because it is difficult to prevent the crystallization of the complexes even using liquid nitrogen. The XDR data indicate that one of the complexes axis has 52 Å of length, agreeing with a structure containing behenate-lanthanide ion-behenate. The structures of the complexes were not fully elucidated and more analyses are necessary. The complexes presented a molar ratio of 3:1 (L:M) and were formulated as Bh_3Eu, Bh_3Nd, Bh_3Dy, Bh_3Tb e Bh_3Yb (Bh = behenate anion). (author)

  9. Silver Nanoparticles: Synthesis, Characterization, Properties, Applications, and Therapeutic Approaches

    Zhang, Xi-Feng; Liu, Zhi-Guo; Shen, Wei; Gurunathan, Sangiliyandi

    2016-01-01

    Recent advances in nanoscience and nanotechnology radically changed the way we diagnose, treat, and prevent various diseases in all aspects of human life. Silver nanoparticles (AgNPs) are one of the most vital and fascinating nanomaterials among several metallic nanoparticles that are involved in biomedical applications. AgNPs play an important role in nanoscience and nanotechnology, particularly in nanomedicine. Although several noble metals have been used for various purposes, AgNPs have been focused on potential applications in cancer diagnosis and therapy. In this review, we discuss the synthesis of AgNPs using physical, chemical, and biological methods. We also discuss the properties of AgNPs and methods for their characterization. More importantly, we extensively discuss the multifunctional bio-applications of AgNPs; for example, as antibacterial, antifungal, antiviral, anti-inflammatory, anti-angiogenic, and anti-cancer agents, and the mechanism of the anti-cancer activity of AgNPs. In addition, we discuss therapeutic approaches and challenges for cancer therapy using AgNPs. Finally, we conclude by discussing the future perspective of AgNPs. PMID:27649147

  10. Synthesis and characterization of CdS/PVA nanocomposite films

    Wang, Hongmei; Fang, Pengfei; Chen, Zhe; Wang, Shaojie

    2007-08-01

    A series CdS/PVA nanocomposite films with different amount of Cd salt have been prepared by means of the in situ synthesis method via the reaction of Cd 2+-dispersed poly vinyl-alcohol (PVA) with H 2S. The as-prepared films were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), ultraviolet-visible (UV-vis) absorption, photoluminescence (PL) spectra, Fourier transform infrared spectroscope (FTIR) and thermogravimetric analysis (TGA). The XRD results indicated the formation of CdS nanoparticles with hexagonal phase in the PVA matrix. The primary FTIR spectra of CdS/PVA nanocomposite in different processing stages have been discussed. The vibrational absorption peak of Cd sbnd S bond at 405 cm -1 was observed, which further testified the generation of CdS nanoparticles. The TGA results showed incorporation of CdS nanoparticles significantly altered the thermal properties of PVA matrix. The photoluminescence and UV-vis spectroscopy revealed that the CdS/PVA films showed quantum confinement effect.

  11. Synthesis and characterization of CdS/PVA nanocomposite films

    Wang Hongmei; Fang Pengfei; Chen Zhe; Wang Shaojie

    2007-01-01

    A series CdS/PVA nanocomposite films with different amount of Cd salt have been prepared by means of the in situ synthesis method via the reaction of Cd 2+ -dispersed poly vinyl-alcohol (PVA) with H 2 S. The as-prepared films were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), ultraviolet-visible (UV-vis) absorption, photoluminescence (PL) spectra, Fourier transform infrared spectroscope (FTIR) and thermogravimetric analysis (TGA). The XRD results indicated the formation of CdS nanoparticles with hexagonal phase in the PVA matrix. The primary FTIR spectra of CdS/PVA nanocomposite in different processing stages have been discussed. The vibrational absorption peak of Cd-S bond at 405 cm -1 was observed, which further testified the generation of CdS nanoparticles. The TGA results showed incorporation of CdS nanoparticles significantly altered the thermal properties of PVA matrix. The photoluminescence and UV-vis spectroscopy revealed that the CdS/PVA films showed quantum confinement effect

  12. Synthesis, characterization and physiological activity of some novel isoxazoles.

    NITIN G. GHODILE

    2012-07-01

    Full Text Available Hushare VJ, Rajput PR, Malpani MO, Ghodile NG. 2012. Synthesis, characterization and physiological activity of some novel isoxazoles. Nusantara Bioscience 4: 81-85. A series of chlorosubstituted 4-aroylisoxazoles have been synthesized by refluxing chlorosubstituted-3-aroylflavones and 3-alkoylchromone with hydroxylamine hydrochloride in dioxane medium containing 0.5 mL piperidine. Chlorosubstituted-3-aroylflavones and chlorosubstituted-3-alkoylchromone were prepared by refluxing them separately with iodine crystal in ethanol. Initially chlorosubstituted-3-aroylflavanones and 3-alkoylchromanone were prepared by the interaction of different aromatic and aliphatic aldehydes with 1-(2’-hydroxy-3’,5’-dichlorophenyl-3-phenyl-1,3-propanedione. Constitutions of synthesized compounds were confirmed on the basis of elemental analysis, molecular weight determination, UV-Visible, I.R. and 1H-NMR spectral data. The titled compounds were evaluated for their growth promoting activity on some flowering plants viz. Papaver rhoeas, Calendula officinalise, Gladiola tristis, Gaillardia aristata, Dianthus chinensis, and Iberis sp. (candytuft. The results indicate that applicated plants had higher shoots and more number of leaves.

  13. Synthesis and characterization of Ce doped MFI zeolite

    Kalita, Banani; Talukdar, Anup K.

    2012-01-01

    Highlights: ► Cerium was incorporated into the tetrahedral position of MFI zeolite structure. ► Unit cell volume increases with an increase of Ce content in the framework of MFI. ► A band at 310 nm in the UV–vis spectra indicates Ce incorporation in MFI structure. ► The mass loss (%) in the region 373–423 K decreases with increase of Ce in MFI. - Abstract: Ce doped MFI (mobil five) zeolites with different Si to (Ce + Al) and different Ce to Al ratios were synthesized by a hydrothermal synthesis method. All the samples were characterized by different techniques such as X-ray diffraction, Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), UV–vis diffuse reflectance spectroscopy (DRS) and scanning electron microscopy (SEM). The results showed that almost pure MFI phase was obtained in all cases with incorporation of cerium metal into the framework. The increase in unit cell parameters observed with an increase in Ce content is indicative of incorporation of Ce into the framework structure of microporous material MFI. Corroboration of the framework incorporation of Ce into the MFI zeolite structure was also obtained from the UV–vis DRS spectra by the presence of an absorption band at 280 nm. TGA and SEM of the samples provide complementary evidence for Ce incorporation into the framework MFI structure.

  14. Synthesis, characterization and structural refinement of polycrystalline uranium substituted zirconolite

    Shrivastava, O.P.; Narendra Kumar; Sharma, I.B.

    2005-01-01

    Ceramic precursors of Zirconolite (CaZrTi 2 O 7 ) family have a remarkable property of substitution Zr 4+ cationic sites. This makes them potential material for nuclear waste management in 'synroc' technology. In order to simulate the mechanism of partial substitution of zirconium by tetravalent actinides, a solid phase of composition CaZr 0.95 U 0.5 Ti 2 O 7 has been synthesized through ceramic route by taking calculated quantities of oxides of Ca, Ti and nitrates of uranium and zirconium respectively. Solid state synthesis has been carried out by repeated pelletizing and sintering the finely powdered oxide mixture in a muffle furnace at 1050 degC. The polycrystalline solid phase has been characterized by its typical powder diffraction pattern. Step analysis data has been used for ab initio calculation of structural parameters. The uranium substituted zirconolite crystallizes in monoclinic symmetry with space group C2/c (15). The following unit cell parameters have been calculated: a =12.4883(15), b =7.2448(5), c 11.3973(10) and β = 100.615(9)0. The structure was refined to satisfactory completion. The Rp and Rwp are found to be 7.48% and 9.74% respectively. (author)

  15. Encapsulated Nanoparticle Synthesis and Characterization for Improved Storage Fluids: Preprint

    Glatzmaier, G. C.; Pradhan, S.; Kang, J.; Curtis, C.; Blake, D.

    2010-10-01

    Nanoparticles are typically composed of 50--500 atoms and exhibit properties that are significantly different from the properties of larger, macroscale particles that have the same composition. The addition of these particles to traditional fluids may improve the fluids' thermophysical properties. As an example, the addition of a nanoparticle or set of nanoparticles to a storage fluid may double its heat capacity. This increase in heat capacity would allow a sensible thermal energy storage system to store the same amount of thermal energy in half the amount of storage fluid. The benefit is lower costs for the storage fluid and the storage tanks, resulting in lower-cost electricity. The goal of this long-term research is to create a new class of fluids that enable concentrating solar power plants to operate with greater efficiency and lower electricity costs. Initial research on this topic developed molecular dynamic models that predicted the energy states and transition temperatures for these particles. Recent research has extended the modeling work, along with initiating the synthesis and characterization of bare metal nanoparticles and metal nanoparticles that are encapsulated with inert silica coatings. These particles possess properties that make them excellent candidates for enhancing the heat capacity of storage fluids.

  16. Synthesis and Characterization of Metal Phosphates for Photocatalytic Applications

    Al-Sabban, Bedour

    2012-07-01

    Solar energy is the most abundant efficient and important source of renewable energy. The objective of this study is to develop highly efficient visible light responsive photocatalysts for overall water splitting. This is done by using silver or copper containing materials. Phosphate compounds have caught much attention due to their rigid structure, thermal stability and resistance to chemical attacks. Solid phosphates can be prepared by direct solid-state reaction between metal cations and phosphate anions at high temperatures. Double metal phosphates of the Nasion-type structure had shown further technological importance. It has been reported that well-crystallized double metal phosphate particles have excellent ordering and cationic conduction channels in the Nasicon framework. In this study, several Nasion-type structured materials have been synthesized by solid-state method (e.g. CuTi2(PO4)3 and AgTi2(PO4)3) heated up under different temperatures (400–1100C) in N2 or air atmosphere. These materials were characterized by XRD, SEM, DR-UV-Vis spectroscopy and tested for photocatalytic applications. A new method for direct synthesis of photoelectrode on Ti Plate had been demonstrated. Further investigations on controlling the size and morphology for better performance of single and double metal phosphates will be done.

  17. Synthesis, characterization and potential utility of doped ceramics based catalysts

    Sharma, Ritika; Yadav, Deepshikha; Singh, G. P.; Vyas, G.; Bhojak, N.

    2018-05-01

    Excessive utilization of petrol, diesel and other fossil fuels, continuous increase in their prices, and the big problem of carbon dioxide mission have encouraged scientists and technologist to find either new sources of energy or to develop technologies for the sustainable utilization of fuel. Biofuels are the only energy technologies that can resolve the problem of carbon dioxide emission in the atmosphere as well as reduce the amount of fossil fuel burned. Bio ethanol and biodiesel are the most common types of biofuel which are being used at present. Biodiesel has become more interesting for all the researchers in present scenario. Various feedstock viz. edible, nonedible oils, waste cooking oil, animal fat, algae etc, are using for the production of biodiesel worldwide according to their availability. Selection of efficient heterogeneous catalysts for biodiesel preparation still needs more attention of researchers. The present investigation deals with determination of synthesis, characterization and applications of doped ceramic based materials in different medium. Two of doped ceramic based catalysts which has been potentially used for the production of biodiesel. The Engine performance of biodiesel samples, made from industrial waste oils and ceramic based catalyst, have also been investigated and found up to satisfactory levels.

  18. Synthesis and characterization of graphene oxide using modified Hummer's method

    Kaur, Manpreet; Kaur, Harsimran; Kukkar, Deepak

    2018-05-01

    In the present study, a simple approach has been followed for the synthesis of graphene oxide (GO) using modified Hummers method in which graphite powder was oxidized in the presence of concentrated H2SO4 and KMnO4. The amount of NaNO3 and KMnO4 was varied to produce sheet like structure. The varied concentrations of NaNO3 and KMnO4 resulted in yielding large amount of the product. Structural, morphological and physicochemical features of the product were studied using UV-Visible spectrophotometer, Fourier Transform infrared spectroscopy (FTIR), and crystal structure was determined using X-ray powder diffraction (XRD). UV-Vis spectra of GO was observed at a maximum absorption of 230 nm due to (π-π*) transition of atomic carbon-carbon bonds. FTIR spectra revealed the presence of oxygen containing functional groups which ensures the complete exfoliation of graphite into graphene oxide X-ray powder diffraction pattern of the product showed the diffraction peak at (2θ = 26.7°) with an interlayer spacing of 0.334 nm. All the above characterizations successfully confirmed the formation of GO.

  19. Hydrothermal synthesis and characterization of zirconia based catalysts

    Caillot, T.; Salama, Z.; Chanut, N.; Cadete Santos Aires, F. J.; Bennici, S.; Auroux, A.

    2013-07-01

    In this work, three equimolar mixed oxides ZrO2/CeO2, ZrO2/TiO2, ZrO2/La2O3 and a reference ZrO2 have been synthesized by hydrothermal method. The structural and surface properties of these materials have been fully characterized by X-ray diffraction, transmission electron microscopy, surface area measurement, chemical analysis, XPS, infrared spectroscopy after adsorption of pyridine and adsorption microcalorimetry of NH3 and SO2 probe molecules. All investigated mixed oxides are amphoteric and possess redox centers on their surface. Moreover, hydrothermal synthesis leads to catalysts with higher surface area and with better acid-base properties than classical coprecipitation method. Both Lewis and Brønsted acid sites are present on the surface of the mixed oxides. Compared to the other samples, the ZrO2/TiO2 material appears to be the best candidate for further application in acid-base catalysis.

  20. Synthesis, characterization, applications, and challenges of iron oxide nanoparticles

    Ali, Attarad; Zafar, Hira; Zia, Muhammad; ul Haq, Ihsan; Phull, Abdul Rehman; Ali, Joham Sarfraz; Hussain, Altaf

    2016-01-01

    Recently, iron oxide nanoparticles (NPs) have attracted much consideration due to their unique properties, such as superparamagnetism, surface-to-volume ratio, greater surface area, and easy separation methodology. Various physical, chemical, and biological methods have been adopted to synthesize magnetic NPs with suitable surface chemistry. This review summarizes the methods for the preparation of iron oxide NPs, size and morphology control, and magnetic properties with recent bioengineering, commercial, and industrial applications. Iron oxides exhibit great potential in the fields of life sciences such as biomedicine, agriculture, and environment. Nontoxic conduct and biocompatible applications of magnetic NPs can be enriched further by special surface coating with organic or inorganic molecules, including surfactants, drugs, proteins, starches, enzymes, antibodies, nucleotides, nonionic detergents, and polyelectrolytes. Magnetic NPs can also be directed to an organ, tissue, or tumor using an external magnetic field for hyperthermic treatment of patients. Keeping in mind the current interest in iron NPs, this review is designed to report recent information from synthesis to characterization, and applications of iron NPs. PMID:27578966

  1. L-arginine modified magnetic nanoparticles: green synthesis and characterization

    Bagherpour, A. R.; Kashanian, F.; Seyyed Ebrahimi, S. A.; Habibi-Rezaei, M.

    2018-02-01

    In recent years, there has been considerable interest in Arg which is a unique, nontoxic, and biocompatible biomolecule since it can be utilized as an agent for the functionalization and subsequent stabilization of MNPs against oxidation and aggregation, during or after a synthesis procedure. Our studies demonstrate that Arg has great impacts on MNPs with the decreasing size of the particle. Also, saturation magnetization and electrostatic interactions of RMNPs have a direct impact on biological molecules such as proteins and nucleic acids. By controlling the concentration of Arg, it is possible to accurately control the above-mentioned characteristics, which are useful tools for applications such as connecting to antibodies, catalysis, drug loading, and modification of MNP stability. In the current study, three RMNPs with different Arg densities, i.e. 0.42, 1.62, and 2.29 μg per mg were successfully synthesized through a simple co-precipitation method (named p 0.5, p 1, and p 1.5, respectively) and verified by colorimetric determination. Also, the as-synthesized RMNP powders were characterized by XRD, SEM/EDAX, FTIR, VSM, and zeta potential analysis. The presence of a magnetic core was proved by XRD, FTIR, and EDAX. Colorimetric analysis showed the existence of Arg in the synthesized samples. According to the zeta potential and VSM results, increasing the cap of Arg on the MNP surface leads to an increase in the surface charge and decrease in the magnetization of the RMNPs, respectively.

  2. Self-organised synthesis of Rh nanostructures with tunable chemical reactivity

    Lizzit S

    2007-01-01

    Full Text Available AbstractNonequilibrium periodic nanostructures such as nanoscale ripples, mounds and rhomboidal pyramids formed on Rh(110 are particularly interesting as candidate model systems with enhanced catalytic reactivity, since they are endowed with steep facets running along nonequilibrium low-symmetry directions, exposing a high density of undercoordinated atoms. In this review we report on the formation of these novel nanostructured surfaces, a kinetic process which can be controlled by changing parameters such as temperature, sputtering ion flux and energy. The role of surface morphology with respect to chemical reactivity is investigated by analysing the carbon monoxide dissociation probability on the different nanostructured surfaces.

  3. Synthesis and characterization of novel polyacid-stabilized latexes.

    Yang, Pengcheng; Armes, S P

    2012-09-18

    A series of novel polyacid macromonomers based on 2-hydroxypropyl methacrylate (HPMA) were prepared by atom transfer radical polymerization (ATRP) via a two-step route. First, a range of well-defined PHPMA homopolymer precursors were synthesized by ATRP using a tertiary amine-functionalized initiator, 2-(dimethylamino)ethyl-2-bromoisobutyrylamide, and a CuCl/2, 2'-bipyridine (bpy) catalyst in alcoholic media at 50 °C. ATRP polymerizations were relatively slow and poorly controlled in pure isopropanol (IPA), especially when targeting higher degrees of polymerization (DP > 30). Improved control was achieved by addition of water: low polydispersity (M(w)/M(n) propyl methacrylate) (PSPMA) macromonomers by quaternizing the tertiary amine end-group with excess 4-vinylbenzyl chloride, followed by esterification of the pendent hydroxyl groups using excess succinic anhydride at 20 °C. These polyacid macromonomers were evaluated as reactive steric stabilizers for polystyrene latex synthesis under either aqueous emulsion polymerization or alcoholic dispersion polymerization conditions. Near-monodisperse polystyrene latexes were obtained via aqueous emulsion polymerization using 10 wt % PSPMA macromonomer (with respect to styrene monomer) with various initiators as evidenced by scanning electron microscopy, disk centrifuge photosedimentometry and light scattering studies. PSPMA macromomer concentrations as low as 1.0 wt % also produced near-monodisperse latexes, suggesting that these PSPMA macromonomers are highly effective stabilizers. Alcoholic dispersion polymerization of styrene conducted in various ethanol/water mixtures with 10 wt % PSPMA(50) macromonomer produced relatively large near-monodisperse latexes. Increasing the water content in such formulations led to smaller latexes, as expected. Control experiments conducted with 10 wt % PSPMA(50) homopolymer produced relatively large polydisperse latexes via emulsion polymerization and only macroscopic precipitates via

  4. Synthesis of benzamides by microwave assisted ring opening of less reactive dimethylaminobenzylidene oxazolone

    Saurabh C. Khadse

    2017-02-01

    Full Text Available This paper presents the synthesis of some benzamide compounds (B1–B10 by microwave-assisted ring opening of 4-(4-dimethylaminobenzylidene-2-phenyl-5-oxazolone (AZ4. By conventional synthesis involving heating, it was found difficult to obtain ring-opened products, probably due to poor tendency of the carbonyl carbon (C5 of AZ4 to undergo nucleophilic attack by mono/or disubstituted anilines. Microwave assisted reactions were easy to perform, have reduced the reaction time and produced good yields.

  5. Entrainer selection for the synthesis of fatty acid esters by entrainer-based reactive distillation

    Jong, de M.C.; Zondervan, E.; Dimian, A.C.; Haan, de A.B.

    2010-01-01

    In this research it is demonstrated that, due to the similarities between Entrainer-based Reactive Distillation and azeotropic distillation, the same selection rules can be applied to select a suitable entrainer. From a list of suitable entrainers for the azeotropic distillation of isopropanol and

  6. Synthesis and Characterization of Polyfunctional Polyhedral Silsesquioxane Cages

    Sulaiman, Santy

    Recent studies on octameric polyhedral silsesquioxanes, (RSiO1.5 )8, indicate that the silsesquioxane cage is not just a passive component but appears to be involved in electron delocalization with conjugated organic tethers in the excited state. This dissertation presents the synthesis and characterization of (RSiO1.5)8 molecules with unique photophysical properties that provide support for the existence of conjugation that involves the (RSiO1.5)8 cage. The dissertation first discusses the elaboration of octavinylsilsesquioxane via cross-metathesis to form styrenyl-functionalized octasilsesquioxane molecules. Subsequent Heck coupling reactions of p-bromostyrenyl derivative provides vinylstilbene-functionalized octasilsesquioxane. The amino derivative, NH2VinylStilbeneOS, show highly red-shifted emission spectrum (100 nm from the simple organic analog p-vinylstilbene) and high two-photon absorption (TPA) cross-section value (100 GM/moiety), indicating charge-transfer processes involving the silsesquioxane cage as the electron acceptor. The unique photophysical properties of polyfunctional luminescent cubic silsesquioxanes synthesized from ortho-8-, (2,5)-16-, and 24-brominated octaphenylsilsesquioxane (OPS) via Heck coupling show how the steric interactions of the organic tethers at the silsesquioxane cage corner affect conjugation with the silsesquioxane cage. Furthermore, the high TPA cross-section (10 GM/moiety) and photoluminescence quantum yield (20%) of OPS functionalized with 24 acetoxystyrenyl groups suggest that the existence excited states in these molecules with similar energies and decay rates: normal radiative pi- pi* transition and charge transfer involving the silsesquioxane cage. The fluoride ion-catalyzed rearrangement reactions of cage and polymeric silsesquioxanes provide a convenient route to a mixture of deca- and dodecameric silsesquioxane molecules in high yields, giving us the opportunity to investigate the effect of silsesquioxane cage

  7. Synthesis and Characterization of Chemically Etched Nanostructured Silicon

    Mughal, Asad Jahangir

    2012-05-01

    Silicon is an essential element in today’s modern world. Nanostructured Si is a more recently studied variant, which has currently garnered much attention. When its spatial dimensions are confined below a certain limit, its optical properties change dramatically. It transforms from an indirect bandgap material that does not absorb or emit light efficiently into one which can emit visible light at room temperatures. Although much work has been conducted in understanding the properties of nanostructured Si, in particular porous Si surfaces, a clear understanding of the origin of photoluminescence has not yet been produced. Typical synthesis approaches used to produce nanostructured Si, in particular porous Si and nanocrystalline Si have involved complex preparations used at high temperatures, pressures, or currents. The purpose of this thesis is to develop an easier synthesis approach to produce nanostructured Si as well as arrive at a clearer understanding of the origin of photoluminescence in these systems. We used a simple chemical etching technique followed by sonication to produce nanostructured Si suspensions. The etching process involved producing pores on the surface of a Si substrate in a solution containing hydrofluoric acid and an oxidant. Nanocrystalline Si as well as nanoscale amorphous porous Si suspensions were successfully synthesized using this process. We probed into the phase, composition, and origin of photoluminescence in these materials, through the use of several characterization techniques. TEM and SEM were used to determine morphology and phase. FT-IR and XPS were employed to study chemical compositions, and steady state and time resolved optical spectroscopy techniques were applied to resolve their photoluminescent properties. Our work has revealed that the type of oxidant utilized during etching had a significant impact on the final product. When using nitric acid as the oxidant, we formed nanocrystalline Si suspensions composed of

  8. Synthesis and characterization of photoswitchable fluorescent silica nanoparticles

    Fölling, J.; Polyakova, S.; Belov, V.; van Blaaderen, A.; Bossi, M.L.; Hell, S.W.

    2008-01-01

    We have designed and synthesized a new functional (amino reactive) highly efficient fluorescent molecular switch (FMS) with a photochromic diarylethene and a rhodamine fluorescent dye. The reactive group in this FMS -N-hydroxysuccinimide ester- allows selective labeling of amino containing molecules

  9. Synthesis, Characterization, and Toxicity Evaluation of Dextran-Coated Iron Oxide Nanoparticles

    Mihaela Balas

    2017-02-01

    Full Text Available We report the synthesis of dextran-coated iron oxide magnetic nanoparticles (DIO-NPs with spherical shape and uniform size distribution as well as their accumulation and toxic effects on Jurkat cells up to 72 h. The characterization of dextran-coated maghemite nanoparticles was done by X-ray diffraction and dynamic light scattering analyses, transmission electron microscopy imaging, attenuated total reflectance Fourier transform infrared (ATR-FTIR spectroscopy, magnetic hysteresis, and relaxometry measurements. The quantification of DIO-NPs intracellular uptake showed a progressive accumulation of iron as a function of time and dose accompanied by additional lysosome formation and an increasing darkening exhibited by a magnetic resonance imaging (MRI scanner. The cytotoxicity assays revealed a decrease of cell viability and a loss of membrane integrity in a time- and dose-dependent manner. Exposure to DIO-NPs determined an increase in reactive oxygen species level up to 72 h. In the first two days of exposure, the level of reduced glutathione decreased and the amount of malondyaldehyde increased, but at the end of the experiment, their concentrations returned to control values. These nanoparticles could be used as contrast agents for MRI but several parameters concerning their interaction with the cells should be taken into consideration for a safe utilization.

  10. Graphene oxide-modified ZnO particles: synthesis, characterization, and antibacterial properties

    Zhong LL

    2015-08-01

    Full Text Available Linlin Zhong, Kyusik Yun Department of Bionanotechnology, Gachon University, Gyeonggi-do, Republic of Korea Abstract: Nanosized ZnO particles with diameters of 15 nm were prepared with a solution precipitation method at low cost and high yield. The synthesis of the particles was functionalized by the organic solvent dimethylformamide, and the particles were covalently bonded to the surface of graphene oxide. The morphology of the graphene oxide sheets and ZnO particles was confirmed with field emission scanning electron microscopy and biological atomic force microscopy. Fourier transform infrared spectroscopy and X-ray diffraction were used to analyze the physical and chemical properties of the ZnO/graphene oxide composites that differed from those of the individual components. Enhanced electrochemical properties were detected with cyclic voltammetry, with a redox peak of the composites at 0.025 mV. Excellent antibacterial activity of ZnO/graphene oxide composites was observed with a microdilution method in which minimum inhibitory concentrations of 6.25 µg/mL for Escherichia coli and Salmonella typhimurium, 12.5 µg/mL for Bacillus subtilis, and 25 µg/mL for Enterococcus faecalis. After further study of the antibacterial mechanism, we concluded that a vast number of reactive oxygen species formed on the surface of composites, improving antibacterial properties. Keywords: graphene oxide, ZnO, characterization, antibacterial property

  11. Synthesis, characterization, and in vitro biological evaluation of highly stable diversely functionalized superparamagnetic iron oxide nanoparticles

    Bhattacharya, Dipsikha; Sahu, Sumanta K.; Banerjee, Indranil; Das, Manasmita; Mishra, Debashish; Maiti, Tapas K.; Pramanik, Panchanan

    2011-01-01

    In this article, we report the design and synthesis of a series of well-dispersed superparamagnetic iron oxide nanoparticles (SPIONs) using chitosan as a surface modifying agent to develop a potential T 2 contrast probe for magnetic resonance imaging (MRI). The amine, carboxyl, hydroxyl, and thiol functionalities were introduced on chitosan-coated magnetic probe via simple reactions with small reactive organic molecules to afford a series of biofunctionalized nanoparticles. Physico-chemical characterizations of these functionalized nanoparticles were performed by TEM, XRD, DLS, FTIR, and VSM. The colloidal stability of these functionalized iron oxide nanoparticles was investigated in presence of phosphate buffer saline, high salt concentrations and different cell media for 1 week. MRI analysis of human cervical carcinoma (HeLa) cell lines treated with nanoparticles elucidated that the amine-functionalized nanoparticles exhibited higher amount of signal darkening and lower T 2 relaxation in comparison to the others. The cellular internalization efficacy of these functionalized SPIONs was also investigated with HeLa cancer cell line by magnetically activated cell sorting (MACS) and fluorescence microscopy and results established selectively higher internalization efficacy of amine-functionalized nanoparticles to cancer cells. These positive attributes demonstrated that these nanoconjugates can be used as a promising platform for further in vitro and in vivo biological evaluations.

  12. Synthesis and Characterization of Silver Nanoparticles for an Undergraduate Laboratory

    Orbaek, Alvin W.; McHale, Mary M.; Barron, Andrew R.

    2015-01-01

    The aim of this simple, quick, and safe laboratory exercise is to provide undergraduate students an introduction to nanotechnology using nanoparticle (NP) synthesis. Students are provided two procedures that allow for the synthesis of different yet controlled sizes of silver NPs. After preparing the NPs, the students perform UV-visible…

  13. SYNTHESIS, CHARACTERIZATION AND BIO-ACTIVITY OF SOME ...

    Preferred Customer

    Organophosphorus compounds have wide range of applications in the industrial, agricultural and medicinal chemistry owing to their unique physicochemical and biological properties. Their utility as reagents and potential synthons in organic synthesis is gaining increased attention [1]. Synthesis of a-aminophosphonates, ...

  14. Synthesis and characterization of DNA minor groove binding alkylating agents.

    Iyer, Prema; Srinivasan, Ajay; Singh, Sreelekha K; Mascara, Gerard P; Zayitova, Sevara; Sidone, Brian; Fouquerel, Elise; Svilar, David; Sobol, Robert W; Bobola, Michael S; Silber, John R; Gold, Barry

    2013-01-18

    Derivatives of methyl 3-(1-methyl-5-(1-methyl-5-(propylcarbamoyl)-1H-pyrrol-3-ylcarbamoyl)-1H-pyrrol-3-ylamino)-3-oxopropane-1-sulfonate (1), a peptide-based DNA minor groove binding methylating agent, were synthesized and characterized. In all cases, the N-terminus was appended with an O-methyl sulfonate ester, while the C-terminus group was varied with nonpolar and polar side chains. In addition, the number of pyrrole rings was varied from 2 (dipeptide) to 3 (tripeptide). The ability of the different analogues to efficiently generate N3-methyladenine was demonstrated as was their selectivity for minor groove (N3-methyladenine) versus major groove (N7-methylguanine) methylation. Induced circular dichroism studies were used to measure the DNA equilibrium binding properties of the stable sulfone analogues; the tripeptide binds with affinity that is >10-fold higher than that of the dipeptide. The toxicities of the compounds were evaluated in alkA/tag glycosylase mutant E. coli and in human WT glioma cells and in cells overexpressing and under-expressing N-methylpurine-DNA glycosylase, which excises N3-methyladenine from DNA. The results show that equilibrium binding correlates with the levels of N3-methyladenine produced and cellular toxicity. The toxicity of 1 was inversely related to the expression of MPG in both the bacterial and mammalian cell lines. The enhanced toxicity parallels the reduced activation of PARP and the diminished rate of formation of aldehyde reactive sites observed in the MPG knockdown cells. It is proposed that unrepaired N3-methyladenine is toxic due to its ability to directly block DNA polymerization.

  15. Reductive reactivity of iron(III) oxides in the east china sea sediments: characterization by selective extraction and kinetic dissolution.

    Chen, Liang-Jin; Zhu, Mao-Xu; Yang, Gui-Peng; Huang, Xiang-Li

    2013-01-01

    Reactive Fe(III) oxides in gravity-core sediments collected from the East China Sea inner shelf were quantified by using three selective extractions (acidic hydroxylamine, acidic oxalate, bicarbonate-citrate buffered sodium dithionite). Also the reactivity of Fe(III) oxides in the sediments was characterized by kinetic dissolution using ascorbic acid as reductant at pH 3.0 and 7.5 in combination with the reactive continuum model. Three parameters derived from the kinetic method: m 0 (theoretical initial amount of ascorbate-reducible Fe(III) oxides), k' (rate constant) and γ (heterogeneity of reactivity), enable a quantitative characterization of Fe(III) oxide reactivity in a standardized way. Amorphous Fe(III) oxides quantified by acidic hydroxylamine extraction were quickly consumed in the uppermost layer during early diagenesis but were not depleted over the upper 100 cm depth. The total amounts of amorphous and poorly crystalline Fe(III) oxides are highly available for efficient buffering of dissolved sulfide. As indicated by the m 0, k' and γ, the surface sediments always have the maximum content, reactivity and heterogeneity of reactive Fe(III) oxides, while the three parameters simultaneously downcore decrease, much more quickly in the upper layer than at depth. Albeit being within a small range (within one order of magnitude) of the initial rates among sediments at different depths, incongruent dissolution could result in huge discrepancies of the later dissolution rates due to differentiating heterogeneity, which cannot be revealed by selective extraction. A strong linear correlation of the m 0 at pH 3.0 with the dithionite-extractable Fe(III) suggests that the m 0 may represent Fe(III) oxide assemblages spanning amorphous and crystalline Fe(III) oxides. Maximum microbially available Fe(III) predicted by the m 0 at pH 7.5 may include both amorphous and a fraction of other less reactive Fe(III) phases.

  16. Synthesis and characterization of nanoparticles capped with medicinal plant extracts

    Rekulapally, Sujith R.

    In this study, synthesis, characterization and biological application of series nanometal (silver, Ag) and nanometal oxide (titania, TiO2) were carried out. These nanomaterials were prepared using wet-chemistry method and then coated using natural plant extract. Three medicinal plants, namely Zingiber officinale (Ginger), Allium sativum (Garlic) and Capsicum annuum (Chili) were chosen as grafting agent to decrease the side-effects and increase the efficiency of NPs towards living organism. Extraction conditions were controlled under 60-100 °C for 8 hrs. Ag and TiO2 NPs were fabricated using colloidal chemistry and variables were controlled at ambient condition. The band gap of TiO2 NPs used as disinfectant was also modified through coating the medicinal plant extracts. The medicinal plant extracts and coated NPs were measured using spectroscopic methods. Ultraviolet-visible spectra indicated the Ag NPs were formed. The peak at 410 nm resulted from the electrons transferred from their ground to the excited state. The broadened full width at half maximum (FWHM) suggested the ultrafine particles were obtained. The lipid soluble compounds, phenols, tri-terpenoids, flavanoids, capsaicinoids, flavonoids, carotenoids, steroids steroidal glycosides, and vitamins were determined from the high performance liquid chromatographical analyses. X-ray powder diffraction indicated that the face-centered cubic Ag (PDF: 00-004-0783, a = 4.0862A, a = 90°) and anatase TiO2 (PDF: 01-08-1285, a = 3.7845, c = 9.5143A, a = 90°) were obtained using colloidal chemistry. Bactericidal activity indicated that these core-shelled TiO 2 were effective (MBC=0.6 ppm, within 30 mins) at inactivating Gram-positive and Gram-negative bacteria. It is proposed that the medicinal extracts enhanced the potency of NPs against bacteria. From our previous study, the Ag NPs were highly effective at inactivating both bacteria.

  17. Synthesis and characterization of magnetite/PLGA/chitosan nanoparticles

    Ibarra, Jaime; Melendres, Julio; Almada, Mario; Burboa, María G.; Taboada, Pablo; Juárez, Josué; Valdez, Miguel A.

    2015-09-01

    In this work, we report the synthesis and characterization of a new hybrid nanoparticles system performed by magnetite nanoparticles, loaded in a PLGA matrix, and stabilized by different concentrations of chitosan. Magnetite nanoparticles were hydrophobized with oleic acid and entrapped in a PLGA matrix by the emulsion solvent evaporation method, after that, magnetite/PLGA/chitosan nanoparticles were obtained by adding dropwise magnetite/PLGA nanoparticles in chitosan solutions. Magnetite/PLGA nanoparticles produced with different molar ratios did not show significant differences in size and the 3:1 molar ratio showed best spherical shapes as well as uniform particle size. Isothermal titration calorimetry studies demonstrated that the first stage of PLGA-chitosan interaction is mostly regulated by electrostatic forces. Based on a single set of identical sites model, we obtained for the average number of binding sites a value of 3.4, which can be considered as the number of chitosan chains per nanoparticle. This value was confirmed by using a model based on the DLVO theory and fitting zeta potential measurements of magnetite/PLGA/chitosan nanoparticles. From the adjusted parameters, we found that an average number of chitosan molecules of 3.6 per nanoparticle are attached onto the surface of the PLGA matrix. Finally, we evaluated the effect of surface charge of nanoparticles on a membrane model of endothelial cells performed by a mixture of three phospholipids at the air-water interface. Different isotherms and adsorption curves show that cationic surface of charged nanoparticles strongly interact with the phospholipids mixture and these results can be the basis of future experiments to understand the nanoparticles- cell membrane interaction.

  18. Synthesis and characterization of barium ferrite–silica nanocomposites

    Aguilar-González, M.A.; Mendoza-Suárez, G.; Padmasree, K.P.

    2013-01-01

    In this work, we prepared barium ferrite-silica (BaM-SiO 2 ) nanocomposites of different molar ratios by high-energy ball milling, followed by heat-treatment at different temperatures. The microstructure, morphology and magnetic properties were characterized for different synthesis conditions by using X-ray diffraction (XRD), scanning electron microscopy (SEM) and vibrating sample magnetometry (VSM). The results indicate that 15 h of milling was enough to avoid the generation of hematite phase and to get a good dispersion of barium ferrite particles in the ceramic matrix. For milling periods beyond 15 h and heat treatment above 900 °C, the XRD patterns showed the presence of hematite phase caused by the decomposition of BaM. The agglomerate size observed through SEM analysis was around 150 nm with a good BaM dispersion into the SiO 2 matrix. The highest saturation magnetization (Ms) value obtained was 43 emu/g and the corresponding coercivity (Hc) value of 3.4 kOe for the composition 60BaM-40SiO 2 milled for 15 h and heat treated at 900 °C. This coercivity value is acceptable for the application in magnetic recording media. Highlights: • Barium ferrite–silica nanocomposites were prepared by high energy ball milling. • Optimal processing time is 15 h milling and heat treatment at 900 °C. • This is enough to avoid the generation of hematite phase. • Obtain good dispersion of barium ferrite particles in the ceramic matrix • Above this processing time shows the presence of increased amount of hematite

  19. Synthesis and characterization of Ti–Ta–Nb–Mn foams

    Aguilar, C., E-mail: claudio.aguilar@usm.cl [Departamento de Ingeniería Metalúrgica y Materiales, Universidad Técnica Federico Santa María, Av. España 1680, Valparaíso (Chile); Guerra, C. [Departamento de Ingeniería Metalúrgica y Materiales, Universidad Técnica Federico Santa María, Av. España 1680, Valparaíso (Chile); Lascano, S. [Departamento de Ingeniería Mecánica, Universidad Técnica Federico Santa María, Av. España 1680, Valparaíso (Chile); Guzman, D. [Departamento de Metalurgia, Universidad de Atacama, Av. Copayapu 485, Copiapó (Chile); Rojas, P.A. [Escuela de Ingeniería Mecánica, Facultad de Ingeniería, Pontificia Universidad Católica de Valparaíso, Av. Los Carrera, 01567 Quilpué (Chile); Thirumurugan, M. [Departamento de Ingeniería Metalúrgica y Materiales, Universidad Técnica Federico Santa María, Av. España 1680, Valparaíso (Chile); Bejar, L.; Medina, A. [Universidad Michoacana de San Nicolás de Hidalgo, Ciudad Universitaria, Morelia, Michoacán (Mexico)

    2016-01-01

    The unprecedented increase in human life expectancy have produced profound changes in the prevailing patterns of disease, like the observed increased in degenerative disc diseases, which cause degradation of the bones. Ti–Nb–Ta alloys are promising materials to replace the damaged bone due to their excellent mechanical and corrosion resistance properties. In general metallic foams are widely used for medical application due to their lower elastic moduli compare to bulk materials. In this work we studied the synthesis of 34Nb–29Ta–xMn (x: 2, 4 and 6 wt.% Mn) alloy foams (50% v/v) using ammonium hydrogen carbonate as a space holder. Alloys were produced through mechanical alloying in a planetary mill for 50 h. Green compacts were obtained by applying 430 MPa pressure. To remove the space holder from the matrix the green compacts were heated to 180 °C for 1.5 h and after sintered at 1300 °C for 3 h. Foams were characterized by x-ray diffraction, scanning, transmission electron microscopy and optical microscopy. The elastic modulus of the foam was measured as ~ 30 GPa, and the values are almost equal to the values predicted using various theoretical models. - Highlights: • Metallic foams of Ti–34Nb–29Ta–xMn (x: 2, 4 and 6 wt.% Mn) alloys were synthetized. • The macro and micro pore produced have sizes smaller than 600 and 20 μm, respectively. • The macro and micro pores shows good characteristics to cell adhesion and bone ingrowth. • Elastic properties were comparable to that exhibited by cortical bone.

  20. Synthesis and thermoluminescent characterization of lithium niobate doped with erbium

    Landavazo, M.; Brown, F.; Cubillas, F.; Munoz, I.; Cruz Z, E.

    2015-10-01

    Full text: Lithium niobate (Nl) is a synthetic dielectric and is mainly used in optical devices. There are reports on the thermoluminescent property of Nl monocrystals doped with rare earths and excited with X and gamma rays. In this study the Nl was synthesized and doped with erbium (Er) at concentrations of 1, 2 and 4 % mol and was characterized by its Tl property. The synthesis was realized by solid state reaction at 1000 degrees C for 22 hours and the formation of Nl:Er was confirmed by X-ray diffraction, scanning electron microscopy and EDS analysis, finding a new phase (ErNbO 4 ). Was studied the dose-response gamma in a range of 1-1000 Gy, the material showed linear behavior of 1-600 Gy. The brightness curves have maxima at 185 and 285 degrees C to 1% in 183 and 301 degrees C for 2%, respectively. While for the concentration of 4% a maximum in 177 degrees C accompanied by a smaller peak at higher temperature of the glow curve was observed. The Tl response of Nl:Er 4% to 450 Gy was increased 271 times compared to pure Nl. The reproducibility of the Tl signal at ten cycles of irradiation-reading, present a standard deviation of 5%. In Nl:Er 1% Tl signal fades in 21.3% after 24 hours, while in 2 and 4% an unusual fading occurs. The Tl characteristics of Nl:Er synthesized material is of interest to gamma radiation dosimetry of high doses. (Author)

  1. Rare-earth doped boron nitride nanotubes: Synthesis and characterization

    Silva, Wellington Marcos; Sousa, Edesia Martins Barros de, E-mail: wellingtonmarcos@yahoo.com.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2016-07-01

    Full text: Boron nitride is a heat and chemically resistant refractory compound of boron and nitrogen atoms with the chemical formula BN. This structure exists in various crystalline forms that are isoelectronic to a similarly structured carbon lattice. The hexagonal form (h-BN) corresponding to graphite is the most stable and soft among BN polymorph. However, boron nitride nanotubes (BNNTs) were first time synthesized in 1995 [1] and have a type of one-dimensional (1D) nanostructure. Recently the BNNTs have attracted significant interest for scientific and technological applications due to their Wide bandgap. The Wide-bandgap semiconductors doped with rare-earth are considered as a new type of luminescent material, combining special Wide bandgap semiconducting properties with the rare-earth luminescence feature. BNNTs have a stable wide bandgap of 5.5 eV and super thermal and chemical stabilities, which make BNNTs an ideal nanosized luminescent material [2]. In this study, we report a simple and efficient route for the synthesis of BNNTs doped with samarium and europium. High quality BNNTs doped was produced via CVD technique using NH{sub 3} and N{sub 2} gases as source. Boron amorphous, catalyst and oxides rare-earth powder were used as precursor. Detailed studies involving energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), Raman spectroscopy, Fourier-transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) and transmission electron microscope (TEM) were performed in order to characterize the BNNTs as grown. [1] Chopra, N. G.; Luyken, R. J. et al. Science, v. 269, p. 966-967, 1995. [2] Chen, H.; Chen, Y. et al. Adv. Matter. v. 19, p. 1845-1848, 2007. (author)

  2. Rare-earth doped boron nitride nanotubes: Synthesis and characterization

    Silva, Wellington Marcos; Sousa, Edesia Martins Barros de

    2016-01-01

    Full text: Boron nitride is a heat and chemically resistant refractory compound of boron and nitrogen atoms with the chemical formula BN. This structure exists in various crystalline forms that are isoelectronic to a similarly structured carbon lattice. The hexagonal form (h-BN) corresponding to graphite is the most stable and soft among BN polymorph. However, boron nitride nanotubes (BNNTs) were first time synthesized in 1995 [1] and have a type of one-dimensional (1D) nanostructure. Recently the BNNTs have attracted significant interest for scientific and technological applications due to their Wide bandgap. The Wide-bandgap semiconductors doped with rare-earth are considered as a new type of luminescent material, combining special Wide bandgap semiconducting properties with the rare-earth luminescence feature. BNNTs have a stable wide bandgap of 5.5 eV and super thermal and chemical stabilities, which make BNNTs an ideal nanosized luminescent material [2]. In this study, we report a simple and efficient route for the synthesis of BNNTs doped with samarium and europium. High quality BNNTs doped was produced via CVD technique using NH 3 and N 2 gases as source. Boron amorphous, catalyst and oxides rare-earth powder were used as precursor. Detailed studies involving energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), Raman spectroscopy, Fourier-transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) and transmission electron microscope (TEM) were performed in order to characterize the BNNTs as grown. [1] Chopra, N. G.; Luyken, R. J. et al. Science, v. 269, p. 966-967, 1995. [2] Chen, H.; Chen, Y. et al. Adv. Matter. v. 19, p. 1845-1848, 2007. (author)

  3. Synthesis and characterization of magnetite/PLGA/chitosan nanoparticles

    Ibarra, Jaime; Melendres, Julio; Almada, Mario; Juárez, Josué; Valdez, Miguel A; Burboa, María G; Taboada, Pablo

    2015-01-01

    In this work, we report the synthesis and characterization of a new hybrid nanoparticles system performed by magnetite nanoparticles, loaded in a PLGA matrix, and stabilized by different concentrations of chitosan. Magnetite nanoparticles were hydrophobized with oleic acid and entrapped in a PLGA matrix by the emulsion solvent evaporation method, after that, magnetite/PLGA/chitosan nanoparticles were obtained by adding dropwise magnetite/PLGA nanoparticles in chitosan solutions. Magnetite/PLGA nanoparticles produced with different molar ratios did not show significant differences in size and the 3:1 molar ratio showed best spherical shapes as well as uniform particle size. Isothermal titration calorimetry studies demonstrated that the first stage of PLGA-chitosan interaction is mostly regulated by electrostatic forces. Based on a single set of identical sites model, we obtained for the average number of binding sites a value of 3.4, which can be considered as the number of chitosan chains per nanoparticle. This value was confirmed by using a model based on the DLVO theory and fitting zeta potential measurements of magnetite/PLGA/chitosan nanoparticles. From the adjusted parameters, we found that an average number of chitosan molecules of 3.6 per nanoparticle are attached onto the surface of the PLGA matrix. Finally, we evaluated the effect of surface charge of nanoparticles on a membrane model of endothelial cells performed by a mixture of three phospholipids at the air–water interface. Different isotherms and adsorption curves show that cationic surface of charged nanoparticles strongly interact with the phospholipids mixture and these results can be the basis of future experiments to understand the nanoparticles- cell membrane interaction. (paper)

  4. Synthesis, characterization and biological studies of copper oxide nanostructures

    Jillani, Saquf; Jelani, Mohsan; Hassan, Najam Ul; Ahmad, Shahbaz; Hafeez, Muhammad

    2018-04-01

    The development of synthetic methods has been broadly accepted as an area of fundamental importance to the understanding and application of nanoscale materials. It allows the individual to modulate basic parameters such as morphology, particle size, size distributions, and composition. Several methods have been developed to synthesize CuO nanostructures with diverse morphologies, sizes, and dimensions using different chemical and physical based approaches. In this work, CuO nanostructures have been synthesized by aqueous precipitation method and simple chemical deposition method. The characterization of these products has been carried out by the x-ray Diffraction (XRD), Scanning Electron Microscope (SEM), Fourier Transform Infrared (FTIR) and UV–vis spectroscopy. Biological activity such as antibacterial nature of synthesized CuO is also explored. XRD peaks analysis revealed the monoclinic crystalline phase of copper oxide nanostructures. While the rod-like and particle-like morphologies have been observed in SEM results. FTIR spectra have confirmed the formation of CuO nanoparticles by exhibiting its characteristic peaks corresponding to 494 cm‑1 and 604 cm‑1. The energy band gap of the as-prepared CuO nanostructures determined from UV–vis spectra is found to be 2.18 eV and 2.0 eV for precipitation and chemically deposited samples respectively. The antibacterial activity results described that the synthesized CuO nanoparticles showed better activity against Staphylococcus aureus. The investigated results suggested the synthesis of highly stable CuO nanoparticles with significant antibacterial activities.

  5. Synthesis, Characterization, and Electrochemical Properties of Polyaniline Thin Films

    Rami, Soukaina

    Conjugated polymers have been used in various applications (battery, supercapacitor, electromagnetic shielding, chemical sensor, biosensor, nanocomposite, light-emitting-diode, electrochromic display etc.) due to their excellent conductivity, electrochemical and optical properties, and low cost. Polyaniline has attracted the researchers from all disciplines of science, engineering, and industry due to its redox properties, environmental stability, conductivity, and optical properties. Moreover, it is a polymer with fast electroactive switching and reversible properties displayed at low potential, which is an important feature in many applications. The thin oriented polyaniline films have been fabricated using self-assembly, Langmuir-Blodgett, in-situ self-assembly, layer-by-layer, and electrochemical technique. The focus of this thesis is to synthesize and characterize polyaniline thin films with and without dyes. Also, the purpose of this thesis is to find the fastest electroactive switching PANI electrode in different electrolytic medium by studying their electrochemical properties. These films were fabricated using two deposition techniques: in-situ self-assembly and electrochemical deposition. The characterization of these films was done using techniques such as Fourier Transform Infrared Spectroscopy (FTIR), UV-spectroscopy, Scanning Electron Microscope (SEM), and X-Ray Diffraction (XRD). FTIR and UV-spectroscopy showed similar results in the structure of the polyaniline films. However, for the dye incorporated films, since there was an addition in the synthesis of the material, peak locations shifted, and new peaks corresponding to these materials appeared. The 1 layer PANI showed compact film morphology, comparing to other PANI films, which displayed a fiber-like structure. Finally, the electrochemical properties of these thin films were studied using cyclic voltammetry (CV), chronoamperometry (CA), and electrochemical impedance spectroscopy (EIS) in

  6. Reactivity of Heteropolytungstate and Heteropolymolybdate Metal Transition Salts in the Synthesis of Dimethyl Carbonate from Methanol and CO2

    Amro Al-Amro

    2010-07-01

    Full Text Available A series of Keggin-type heteropoly compounds (HPC having different countercations (Co, Fe and different addenda atoms (W, Mo were synthesized and characterized by means of Fourier-Transform Infrared Spectrometer (FT-IR and X-ray powder diffraction (XRD. The catalytic properties of the prepared catalysts for the dimethyl carbonate (DMC synthesis from CO2 and CH3OH were investigated. The experimental results showed that the catalytic activity is significantly influenced by the type of the countercation and addenda atoms transition metal. Among the catalysts examined, Co1.5PW12O40 is the most active for the DMC synthesis, owing to the synergetic effect between Co and W. Investigating the effect of the support showed that the least acidic one (Al2O3 enhanced the conversion but decreased the DMC selectivity in favor of that of methyl formate (MF, while that of dimethoxy methane remained stable.

  7. Versatile and biomass synthesis of iron-based nanoparticles supported on carbon matrix with high iron content and tunable reactivity

    Zhang Dongmao; Shi, Sheldon Q.; Pittman, Charles U.; Jiang Dongping; Che Wen; Gai Zheng; Howe, Jane Y.; More, Karren L.; Antonyraj, Arockiasamy

    2012-01-01

    Iron-based nanoparticles supported on carbon (FeNPs-C) have enormous potential for environmental applications. Reported is a biomass-based method for FeNP-C synthesis that involves pyrolysis of bleached wood fiber pre-mixed with Fe 3 O 4 nanoparticles. This method allows synthesis of iron-based nanoparticles with tunable chemical reactivity by changing the pyrolysis temperature. The FeNP-C synthesized at a pyrolysis temperature of 500 °C (FeNP-C-500) reacts violently (pyrophoric) when exposed to air, while FeNP-C prepared at 800 °C (FeNP-C-800) remains stable in ambient condition for at least 3 months. The FeNPs in FeNP-C-800 are mostly below 50 nm in diameter and are surrounded by carbon. The immediate carbon layer (within 5–15 nm radius) on the FeNPs is graphitized. Proof-of-concept environmental applications of FeNPs-C-800 were demonstrated by Rhodamine 6G and arsenate (V) removal from water. This biomass-based method provides an effective way for iron-based nanoparticle fabrication and biomass utilization.

  8. Synthesis and reactivity of single-phase Be{sub 17}Ti{sub 2} intermetallic compounds

    Kim, Jae-Hwan, E-mail: kim.jaehwan@jaea.go.jp [Breeding Functional Materials Development Group, Sector of Fusion Research and Development, Japan Atomic Energy Agency (Japan); Iwakiri, Hirotomo; Furugen, Tatsuaki [Faculty of Education Elementary and Secondary School Teacher Training Program, University of the Ryukyus, Okinawa (Japan); Nakamichi, Masaru [Breeding Functional Materials Development Group, Sector of Fusion Research and Development, Japan Atomic Energy Agency (Japan)

    2016-01-15

    Highlights: • Preliminary synthesis of single-phase Be{sub 17}Ti{sub 2} was succeeded. • Reactivity difference between beryllium and beryllides may be caused by a lattice strain. • Oxidation of Be{sub 17}Ti{sub 2} at high temperatures results in the formation of TiO{sub 2}. • Simulation results reveal that a stable site for hydrogen at the center of tetrahedron exists. - Abstract: To investigate feasibility for application of Be{sub 17}Ti{sub 2} as a neutron multiplier as well as a refractory material, single-phase Be{sub 17}Ti{sub 2} intermetallic compounds were synthesized using an annealing heat treatment of the starting powder and a plasma sintering method. Scanning electron microscopic observations and X-ray diffraction measurements reveal that the single-phase Be{sub 17}Ti{sub 2} compounds were successfully synthesized. We examined the reactivity of Be{sub 17}Ti{sub 2} with 1% H{sub 2}O and discovered that a larger stoichiometric amount of Ti resulted in the formation of TiO{sub 2} on the surface at high temperatures. This oxidation may also contribute to an increase in both weight gain and generation of H{sub 2}. This suggests that the formation of the Ti-depleted Be{sub 17}Ti{sub 2−x} layer as a result of oxidation facilitates an increased reactivity with H{sub 2}O. To evaluate the safety aspects of Be{sub 17}Ti{sub 2}, we also investigated the hydrogen positions and solution energies based on the first principle. The calculations reveal that there are 10 theoretical sites, where 9 of these sites have hydrogen solution energies with a positive value (endothermic) and 1 site located at the center of a tetrahedron comprising two Be and two Ti atoms gives a negative value (exothermic).

  9. Synthesis, Transfer, and Characterization of Nanoscale 2-Dimensional Materials

    2015-09-01

    Shi Y, Hamsen C, Jia X, Kim KK, Reina A, Hofmann M, Kong J. Synthesis of few-layer hexagonal boron nitride thin film by chemical vapor deposition...hexagonal boron nitride layers. Nano Letters. 2010;10(8):3209–3215. 12. Kim KK, Hsu A, Jia X, Kim SM, Shi Y, Hofmann M, Kong J. Synthesis of...microscopy. Physical Review B. 2009;80(15):155425. 33. Kim KK, Hsu A, Jia X, Kim SM, Shi Y, Hofmann M, Kong J. Synthesis of monolayer hexagonal boron

  10. Synthesis and characterization of cobalt-nichel oxides for the oxygen formation reaction

    Morales G, P.

    2001-01-01

    In this work the compounds of cobalt and nickel oxides and the mixtures of cobalt-nickel were prepared which were characterized and evaluated as electrocatalysts in the oxygen release reaction in alkaline media. The compounds were synthesised by the sol-gel method: heated at 400 and 500 Centigrade. The compounds characterization was realized by thermogravimetry, X-ray diffraction and Scanning electron microscopy. As the Co 3 O 4 and the Ni O as the mixtures Ni O/Co 3 O 4 were obtained as a porous material with a small particle size, characteristics which are presented by cause of the low temperature of synthesis. The electrocatalytic evaluation for the synthesised compounds for the oxygen release reaction was realized by cyclic volt amperometry in a 0.5M KOH solution. The oxides mixtures presented a well electrocatalytic activity to be used in the electrochemical release of oxygen. The current density and the electrochemically active area, in all the cases of mixtures is very higher to the Co 3 O 4 and Ni O ones. Observing with greater clearness the synergic effects, in the obtained mixture at 400 C. The oxides mixtures heated at 400 C were stables for the oxygen formation reaction. Therefore it is be able to say that the Ni O/Co 3 O 4 mixture counts on a great reactive area: electrocatalytic characteristic desirable to be a material used as anode in the electrolysis of water, which increases the oxygen release in the anode and so the hydrogen release in the cathode. (Author)

  11. Hyperbranched Polyethylenebased Macromolecular Architectures: Synthesis, Characterization, and Selfassembly

    Al-Sulami, Ahlam

    2018-01-01

    -b-PNIPAM, and hyperbranched polyethylene-b-poly(solketal acrylate), HBPE-b-PSA, were successfully synthesized by combining CWCP and ATRP. The synthetic methodology includes the following steps; a) synthesis of multifunction hyperbranched polyethylene initiators HBPE

  12. Synthesis and Characterization of Colloidal Metal and Photovoltaic Semiconductor Nanocrystals

    Abulikemu, Mutalifu

    2014-01-01

    -performing photovoltaic nanocrystals contain toxic elements, such as Pb, or scarce elements, such as In; thus, the production of solution-processable nanocrystals from earth-abundant materials using environmentally benign synthesis and processing methods has become a

  13. Combustion synthesis and structural characterization of Li–Ti mixed ...

    pared by combustion method at lower temperatures compared to the conventional high temperature sintering for ... Li–Ti mixed ferrites; combustion synthesis; hysteresis. 1. ... Quantum model - VSM 6000) at an applied field of ±10 kOe.

  14. Synthesis and characterization of actinide metal compounds formed by combustion

    Behrens, R.G.; King, M.A.

    1985-01-01

    This paper briefly describes the results of attempts to synthesize arsenides, phosphides, and antimonides of uranium and thorium using Self-Propagating High-Temperature Synthesis (SHS) techniques. This paper first summarizes the chemistry and thermodynamics of these chemical systems, describes SHS synthesis techniques, and then describes the results of the syntheses using data from powder x-ray diffraction, metallographic, and electron microprobe analyses

  15. Synthesis and Characterization of Highly Intercalated Graphite Bisulfate

    Salvatore, Marcella; Carotenuto, Gianfranco; De Nicola, Sergio; Camerlingo, Carlo; Ambrogi, Veronica; Carfagna, Cosimo

    2017-01-01

    Different chemical formulations for the synthesis of highly intercalated graphite bisulfate have been tested. In particular, nitric acid, potassium nitrate, potassium dichromate, potassium permanganate, sodium periodate, sodium chlorate, and hydrogen peroxide have been used in this synthesis scheme as the auxiliary reagent (oxidizing agent). In order to evaluate the presence of delamination, and pre-expansion phenomena, and the achieved intercalation degree in the prepared samples, the obtain...

  16. Neutronic characterization of cylindrical core of minor excess reactivity in the nuclear reactor IPEN/MB-01 from the measure of neutron flux distribution and its reactivity ratio

    Bitelli, Ulysses d' Utra; Aredes, Vitor O.G.; Mura, Luiz E.C.; Santos, Diogo F. dos; Silva, Alexandre P. da, E-mail: ubitelli@ipen.br, E-mail: vitoraredes@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    When compared to a rectangular parallelepiped configuration the cylindrical configuration of a nuclear reactor core has a better neutron economy because in this configuration the probability of the neutron leakage is smaller, causing an increase in overall reactivity in the system to the same amount of fuel used. In this work we obtained a critical cylindrical configuration with the control rods 89.50% withdraw from the active region of the IPEN/MB-01 core. This is the cylindrical configuration minimum possible excess of reactivity. Thus we obtained a cylindrical configuration with a diameter of only 28 fuel rods with lowest possible excess of reactivity. For this purpose, 112 peripheral fuel rods are removed from standard reactor core (rectangular parallelepiped of 28x28 fuel rods). In this configuration the excesses of reactivity is approximated 279 pcm. From there, we characterize the neutron field by measuring the spatial distribution of the thermal and epithermal neutron flux for the reactor operating power of 83 watts measured by neutron noise analysis technique and 92.08± 0.07 watts measured by activation technique [10]. The values of thermal and epithermal neutron flux in different directions, axial, radial north-south and radial east-west, are obtained in the asymptotic region of the reactor core, away from the disturbances caused by the reflector and control bar, by irradiating thin gold foils infinitely diluted (1% Au - 99% Al) with and without (bare) cadmium cover. In addition to the distribution of neutron flux, the moderator temperature coefficient, the void coefficient, calibration of the control rods were measured. (author)

  17. Synthesis of Highly Reactive Subnano-sized Zero-valent Iron using Smectite Clay Templates

    Gu, Cheng; Jia, Hanzhang; Li, Hui; Teppen, Brian J.; Boyd, Stephen A.

    2010-01-01

    A novel method was developed for synthesizing subnano-sized zero-valent iron (ZVI) using smectite clay layers as templates. Exchangeable Fe(III) cations compensating the structural negative charges of smectites were reduced with NaBH4, resulting in the formation of ZVI. The unique structure of smectite clay, in which isolated exchangeable Fe(III) cations reside near the sites of structural negative charges, inhibited the agglomeration of ZVI resulting in the formation of discrete regions of subnanoscale ZVI particles in the smectite interlayer regions. X-ray diffraction revealed an interlayer spacing of ~ 5 Å. The non-structural iron content of this clay yields a calculated ratio of two atoms of ZVI per three cation exchange sites, in full agreement with the XRD results since the diameter of elemental Fe is 2.5 Å. The clay-templated ZVI showed superior reactivity and efficiency compared to other previously reported forms of ZVI as indicated by the reduction of nitrobenzene; structural Fe within the aluminosilicate layers was nonreactive. At a 1:3 molar ratio of nitrobenzene:non-structural Fe, a reaction efficiency of 83% was achieved, and over 80% of the nitrobenzene was reduced within one minute. These results confirm that non-structural Fe from Fe(III)-smectite was reduced predominantly to ZVI which was responsible for the reduction of nitrobenzene to aniline. This new form of subnano-scale ZVI may find utility in the development of remediation technologies for persistent environmental contaminants, e.g. as components of constructed reactive domains such as reactive caps for contaminated sediments. PMID:20446730

  18. Synthesis of highly reactive subnano-sized zero-valent iron using smectite clay templates.

    Gu, Cheng; Jia, Hanzhong; Li, Hui; Teppen, Brian J; Boyd, Stephen A

    2010-06-01

    A novel method was developed for synthesizing subnano-sized zero-valent iron (ZVI) using smectite clay layers as templates. Exchangeable Fe(III) cations compensating the structural negative charges of smectites were reduced with NaBH(4), resulting in the formation of ZVI. The unique structure of smectite clay, in which isolated exchangeable Fe(III) cations reside near the sites of structural negative charges, inhibited the agglomeration of ZVI resulting in the formation of subnanoscale ZVI particles in the smectite interlayer regions. X-ray diffraction revealed an interlayer spacing of approximately 5 A. The non-structural iron content of this clay yields a calculated ratio of two atoms of ZVI per three cation exchange sites, in full agreement with the X-ray diffraction (XRD) results since the diameter of elemental Fe is 2.5 A. The clay-templated ZVI showed superior reactivity and efficiency compared to other previously reported forms of ZVI as indicated by the reduction of nitrobenzene; structural Fe within the aluminosilicate layers was nonreactive. At a 1:3 molar ratio of nitrobenzene/non-structural Fe, a reaction efficiency of 83% was achieved, and over 80% of the nitrobenzene was reduced within one minute. These results confirm that non-structural Fe from Fe(III)-smectite was reduced predominantly to ZVI which was responsible for the reduction of nitrobenzene to aniline. This new form of subnanoscale ZVI may find utility in the development of remediation technologies for persistent environmental contaminants, for example, as components of constructed reactive domains such as reactive caps for contaminated sediments.

  19. Synthesis of click-reactive HPMA copolymers using RAFT polymerization for drug delivery applications

    Ebbesen, Morten F; Schaffert, D.H.; Crowley, Michael L

    2013-01-01

    This study describes a versatile strategy combining reversible addition fragmentation transfer (RAFT) polymerization and click chemistry to synthesize well-defined, reactive copolymers of N-(2-hydroxypropyl)methacrylamide (HPMA) for drug delivery applications. A novel azide containing monomer N-(3......-azidopropyl)methacrylamide (AzMA) was synthesized and copolymerized with HPMA using RAFT polymerization to provide p(HPMA-co-AzMA) copolymers with high control of molecular weight (∼10–54 kDa) and polydispersity (≤1.06). The utility of the side-chain azide functionality by Cu(I)-catalyzed azide...

  20. Isolation and Spectroscopic Characterization of Reactive Species in Atmospheric and Interstellar Reactions

    Relph, Rachael A.

    2011-12-01

    A critical element to the study of chemical reactions is the characterization of reaction intermediates. Methods have been developed to isolate these transient species in the gas phase and when combined with infrared spectroscopy have proven to be excellent tools for determining the structure and reactivity of key intermediates. The studies presented here exploit these technologies to better understand the chemistry of species involved in atmospheric and interstellar reactions. An excellent example of their utility is in the study of the formation of proton hydrates and HONO in the upper atmosphere by sequential addition of water molecules onto the nitrosonium ion. This reaction only proceeds to products after addition of the fourth water molecule, and isolation and characterization of the intermediate trihydrate, NO+(H 2O)3, shows that this species is formed in three isomeric forms, each with a different water network that controls the degree of bond formation between the nitrosonium ion and an activated water molecule. Many isomeric structures are also seen in the clustering reactions of acetylene which may be a mechanism for the formation of benzene cation in interstellar space. The spectroscopy of the trimer, (C2H2)3 + indicates that this species exists in two major isomer classes; covalent forms, one of which may be benzene, and an ion-molecule complex, comprised of a loosely bound acetylene on a dimer core. Interestingly, this dimer core is different from the cyclobutadiene-like structure observed in dimerized acetylene, and proves to be a robust species on the potential energy surface as it survives further clustering events. Two structural isomers of CO3 -and NO3 - are also investigated, and found to have drastically different infrared spectra which are analyzed in the context of their electronic structure. Isomers in these systems are prepared under different expansion conditions which accounts for their unique spectral signatures.

  1. Synthesis and characterization of triglyceride based thermosetting polymers

    Can, Erde

    2005-07-01

    Plant oils, which are found in abundance in all parts of the world and are easily replenished annually, have the potential to replace petroleum as a chemical feedstock for making polymers. Within the past few years, there has been growing interest to use triglycerides as the basic constituent of thermosetting polymers with the necessary rigidity, strength and glass transition temperatures required for engineering applications. Plant oils are not polymerizable in their natural form, however various functional groups that can polymerize can easily be attached to the triglyceride structure making them ideal cross-linking monomers for thermosetting liquid molding resins. Through this research project a number of thermosetting liquid molding resins based on soybean and castor oil, which is a specialty oil with hydroxyls on its fatty acids, have been developed. The triglyceride based monomers were prepared via the malination of the alcoholysis products of soybean and castor oil with various polyols, such as pentaerythritol, glycerol, and Bisphenol A propoxylate. The malinated glycerides were then cured in the presence of a reactive diluent, such as styrene, to form rigid glassy materials with a wide range of properties. In addition to maleate half-esters, methacrylates were also introduced to the glyceride structure via methacrylation of the soybean oil glycerolysis product with methacrylic anhydride. This product, which contains methacrylic acid as by-product, and its blends with styrene also gave rigid materials when cured. The triglyceride based monomers were characterized via conventional spectroscopic techniques. Time resolved FTIR analysis was used to determine the curing kinetics and the final conversions of polymerization of the malinated glyceride-styrene blends. Dynamic Mechanical Analysis (DMA) was used to determine the thermomechanical behavior of these polymers and other mechanical properties were determined via standard mechanical tests. The use of lignin

  2. Designing Selectivity in Metal-Semiconductor Nanocrystals: Synthesis, Characterization, and Self-Assembly

    Pavlopoulos, Nicholas George

    This dissertation contains six chapters detailing recent advances that have been made in the synthesis and characterization of metal-semiconductor hybrid nanocrystals (HNCs), and the applications of these materials. Primarily focused on the synthesis of well-defined II-VI semiconductor nanorod (NR) and tetrapod (TP) based constructs of interest for photocatalytic and solar energy applications, the research described herein discusses progress towards the realization of key design rules for the synthesis of functional semiconductor nanocrystals (NCs). As such, a blend of novel synthesis, advanced characterization, and direct application of heterostructured nanoparticles are presented. The first chapter is a review summarizing the design, synthesis, properties, and applications of multicomponent nanomaterials composed of disparate semiconductor and metal domains. By coupling two compositionally distinct materials onto a single nanocrystal, synergistic properties can arise that are not present in the isolated components, ranging from self-assembly to photocatalysis. For semiconductor nanomaterials, this was first realized in the ability to tune nanomaterial dimensions from 0-D quantum dot (QD) structures to cylindrical (NR) and branched (TP) structures by exploitation of advanced colloidal synthesis techniques and understandings of NC facet reactivities. The second chapter is focused on the synthesis and characterization of well-defined CdSe-seeded-CdS (CdSe CdS) NR systems synthesized by overcoating of wurtzite (W) CdSe quantum dots with W-CdS shells. 1-dimensional NRs have been interesting constructs for applications such as solar concentrators, optical gains, and photocatalysis. Through synthetic control over CdSe CdS NR systems, materials with small and large CdSe seeds were prepared, and for each seed size, multiple NR lengths were prepared. Through transient absorption studies, it was found that band alignment did not affect the efficiency of charge localization

  3. Using Spectrophotometric Titrations To Characterize Humic Acid Reactivity at Environmental Concentrations

    Janot, N.; Benedetti, M. F. [Univ Paris Diderot, Lab Geochim Eaux, UMR CNRS 7154, IPGP, F-75025 Paris 13 (France); Janot, N.; Reiller, P. E. [CE Saclay, CEA DEN DANS DPC SECR, Lab Speciat Radionucleides and Mol, F-91191 Gif Sur Yvette (France); Korshin, G. V. [Univ Washington, Dept Civil and Environm Engn, Seattle, WA 98195 (United States)

    2010-07-01

    Potentiometric titration is a common method to characterize dissolved organic matter (DOM) reactivity. Because of the sensitivity of pH electrodes, it is necessary to work with very high DOM ({>=}1 g/L) concentrations that are unrealistic compared to those found in natural waters (0. 1 to 100 mg/L). To obtain proton binding data for concentrations closer to environmental values, spectroscopic titration methodology is a viable alternative to traditional potentiometric titrations. Spectrophotometric titrations and UV visible spectra of a diluted solution of purified Aldrich humic acid (5 mg(DOC)/L) are used to estimate changes in proton binding moieties as function of pH and ionic strength after calculation of differential absorbance spectra variations. After electrostatic correction of spectrophotometric data, there is a linear operational correlation between spectrophotometric and potentiometric data which can be used as a transfer function between the two properties. Spectrophotometric titrations are then used to determine the changes of humic acid protonation after adsorption onto alpha-alumina. (authors)

  4. Field characterization of elastic properties across a fault zone reactivated by fluid injection

    Jeanne, Pierre; Guglielmi, Yves; Rutqvist, Jonny; Nussbaum, Christophe; Birkholzer, Jens

    2017-08-01

    We studied the elastic properties of a fault zone intersecting the Opalinus Clay formation at 300 m depth in the Mont Terri Underground Research Laboratory (Switzerland). Four controlled water injection experiments were performed in borehole straddle intervals set at successive locations across the fault zone. A three-component displacement sensor, which allowed capturing the borehole wall movements during injection, was used to estimate the elastic properties of representative locations across the fault zone, from the host rock to the damage zone to the fault core. Young's moduli were estimated by both an analytical approach and numerical finite difference modeling. Results show a decrease in Young's modulus from the host rock to the damage zone by a factor of 5 and from the damage zone to the fault core by a factor of 2. In the host rock, our results are in reasonable agreement with laboratory data showing a strong elastic anisotropy characterized by the direction of the plane of isotropy parallel to the laminar structure of the shale formation. In the fault zone, strong rotations of the direction of anisotropy can be observed. The plane of isotropy can be oriented either parallel to bedding (when few discontinuities are present), parallel to the direction of the main fracture family intersecting the zone, and possibly oriented parallel or perpendicular to the fractures critically oriented for shear reactivation (when repeated past rupture along this plane has created a zone).

  5. Deposition and characterization of NbAIN thin films by reactive magnetron sputtering

    Carvalho, R.G.; Felix, L.C.; Fernandez, D.A.R.; Fontes Junior, A.S.; Oliveira, G.B.; Tentardini, E.K.

    2016-01-01

    The objective of this work was to study NbAlN thin films and the influence of variation in the concentration of aluminum in the crystal structure and oxidation resistance of these coatings. The thin films were deposited by reactive magnetron sputtering and characterized by Grazing Incidence X-ray Diffraction (GIXRD), Energy Dispersive Spectroscopy (EDS) and oxidation tests at high temperatures. NbAlN thin films were deposited and present at concentration of 10, 20 and 42 at% Al. The NbAlN crystalline phase obtained was the δ-NbN, however it was observed a shift of the peaks in the patterns obtained GIXRD of regions for larger angles for these samples, indicating the formation of a solid solution. The higher oxidation resistance temperature was 700° C for the sample with 42 in at% Al. From the SEM analysis it was possible to observe the surface of the film after oxidation, all films showed defects, however the amount of such defects was lower in samples with higher aluminum concentrations. (author)

  6. Deposition and characterization of IrOx nanofoils on carbon nanotube templates by reactive magnetron sputtering

    Chen, Yi-Min; Cai, Jhen-Hong; Huang, Ying-Sheng; Lee, Kuei-Yi; Tsai, Dah-Shyang; Tiong, Kwong-Kau

    2012-01-01

    Large surface area IrO x nanofoils (IrO x NF) were deposited on multi-wall carbon nanotube (MWCNT) templates, forming IrO x /MWCNT nanocomposites, by reactive radio frequency magnetron sputtering using Ir metal target. The structural and spectroscopic properties of IrO x NF were characterized. The micrographs of field emission scanning electron microscopy showed the formation of foil-like structure for the as-deposited samples. Transmission electron microscopy analysis revealed the contiguous presence of glassy iridium oxide, iridium metal, and iridium dioxide nanocrystals in the foil. X-ray photoelectron spectroscopy analysis provided the information of the oxidation states and the stoichiometry of IrO x NF. Raman spectra revealed the amorphous-like phase of the as-deposited IrO x NF. The nanofoil structure provided ultra-high surface area for electrical charge storage which made the IrO x /MWCNT nanocomposites as an attractive candidate for the supercapacitor applications.

  7. Using Spectrophotometric Titrations To Characterize Humic Acid Reactivity at Environmental Concentrations

    Janot, N.; Benedetti, M. F.; Janot, N.; Reiller, P. E.; Korshin, G. V.

    2010-01-01

    Potentiometric titration is a common method to characterize dissolved organic matter (DOM) reactivity. Because of the sensitivity of pH electrodes, it is necessary to work with very high DOM (≥1 g/L) concentrations that are unrealistic compared to those found in natural waters (0. 1 to 100 mg/L). To obtain proton binding data for concentrations closer to environmental values, spectroscopic titration methodology is a viable alternative to traditional potentiometric titrations. Spectrophotometric titrations and UV visible spectra of a diluted solution of purified Aldrich humic acid (5 mg(DOC)/L) are used to estimate changes in proton binding moieties as function of pH and ionic strength after calculation of differential absorbance spectra variations. After electrostatic correction of spectrophotometric data, there is a linear operational correlation between spectrophotometric and potentiometric data which can be used as a transfer function between the two properties. Spectrophotometric titrations are then used to determine the changes of humic acid protonation after adsorption onto alpha-alumina. (authors)

  8. Formation and characterization of titanium nitride and titanium carbide films prepared by reactive sputtering

    Sundgren, J.-E.

    1982-01-01

    Titanium has been reactively r.f. sputtered in mixed Ar-N 2 and Ar-CH 4 discharges on to substrates held at 775 K. The films obtained have been characterized by scanning electron microscopy, X-ray diffraction and by measurements of hardness and electrical resistivity. The compositions of the films have been determined using Auger electron spectroscopy. The processes occurring both on substrates and target surfaces have been studied and it is shown that the latter is of great importance for the composition and structure of deposited films. Titanium nitride films of full density and with electrical resistivity and hardness values close to those of bulk TiN were only obtained in a narrow range close to the stoichiometric composition. Titanium carbide films grown on non-biased substrates were found to have an open structure and thus a low density. A bias applied to the substrate, however, improved the quality of the films. It is also shown that the heat of formation of the compounds plays an important role in the formation of carbides and nitrides. A large value promotes the development of large grains and dense structures. (Auth.)

  9. Characterization and reactivity of soot from fast pyrolysis of lignocellulosic compounds and monolignols

    Trubetskaya, Anna; Brown, Avery; Tompsett, Geoffrey

    2018-01-01

    spectroscopy. The CO2 reactivity of soot was investigated by thermogravimetric analysis. Soot from cellulose was more reactive than soot produced from extractives, lignin and monolignols. Soot reactivity was correlated with the separation distances between adjacent graphene layers, as measured using...... transmission electron microscopy. Particle size, free radical concentration, differences in a degree of curvature and multi-core structures influenced the soot reactivity less than the interlayer separation distances. Soot yield was correlated with the lignin content of the feedstock. The selection...... of the extraction solvent had a strong influence on the soot reactivity. The Soxhlet extraction of softwood and wheat straw lignin soot using methanol decreased the soot reactivity, whereas acetone extraction had only a modest effect....

  10. Uranium and thorium based phosphate matrix: synthesis, characterizations and lixiviation

    Dacheux, N.

    1995-03-01

    In the framework of the search for a ceramic material usable in the radioactive waste storage, uranium and thorium phosphates have been investigated. Their experimental synthesis conditions have been entirely reviewed, they lead to the preparation of four new compounds: U(UO 2 )(PO 4 ) 2 , U 2 O(PO 4 ) 2 , UCIPO 4 , 4H 2 O, and Th 4 (PO 4 ) 4 P 2 O 7 . Experimental evidenced are advanced for non existent compounds such as: U 3 (PO 4 ) 4 , U 2 O 3 P 2 O 7 and Th 3 (PO 4 ) 4 . Characterization by several techniques (X-rays and neutron powder diffractions, UV-Visible and Infra-red spectroscopies, XPS,...) were performed. The ab initio structure determination of U(UO 2 )(PO 4 ) 2 has been achieved by X-rays and refined by neutron diffractions. Through its physico-chemical analysis, we found that this compound was a new mixed valence uranium phosphate in which U 4+ and UO 2 2+ ions are ordered in pairs along parallel chains according to a new type of arrangement. Reaction mechanism, starting from UCIPO 4 , 4H 2 O and based on redox processes of uranium in solid state was set up. From two main matrices U(UO 2 )(PO 4 ) 2 and Th 4 (PO 4 ) 4 P 2 O 7 , solid solutions were studied. They consist of replacement of U(IV) by Th(IV) and reversely. The leaching tests on pure, loaded and doped matrices were performed in terms of storage time, pH of solutions, and determined by the use of solids labelled with 230 U or by the measurement of uranyl concentration by Laser-Induced Time-Resolved Spectro-fluorimetry. Average concentration of uranium in the liquid phase is around 10 -4 M to 10 -6 M. Taking into account the very low solubilities of the studied phosphate ceramics, we estimated their chemical performances promising as an answer to the important nuclear waste problem, if we compare them to the glasses used at the present time. (author)

  11. Transition metal borides. Synthesis, characterization and superconducting properties

    Kayhan, Mehmet

    2013-07-12

    A systematic study was done on the synthesis and superconducting properties of metal rich transition metal borides. Five different binary systems were investigated including the boride systems of niobium, tantalum, molybdenum, tungsten and rhenium. High temperature solid state methods were used in order to synthesize samples of different transition metal borides of the composition M{sub 2}B, MB, M{sub 3}B{sub 2}, MB{sub 2}, and M{sub 2}B{sub 4}. The reactions were carried out in three different furnaces with different sample containers: the electric arc (copper crucible), the high frequency induction furnace (boron nitride, tantalum or glassy carbon crucibles), and the conventional tube furnace (sealed evacuated quartz ampoules). The products obtained were characterized with X-ray powder diffractometry, scanning electron microscopy and energy-dispersive X-ray spectroscopy. Phase analyses and crystal structure refinements using the Rietveld method and based on structure models known from literature were performed. A neutron diffraction measurement was done for W{sub 2}B{sub 4} to allow for a complete crystal structure determination, because of the presence of a heavy element like tungsten and a light element like boron that made it difficult to determine the accurate determination of the boron atom positions and occupancies from X-ray data. A new structure model for W{sub 2}B{sub 4} was proposed. Magnetic measurements in a SQUID magnetometer down to temperatures as low as 1.8 K were performed to several of the products in order to see if the transition metal borides become superconducting at low temperatures, and the results were compared with data from literature. Superconducting properties were found for the following compounds: NbB{sub 2} (T{sub C} = 3.5 K), β-MoB (T{sub C} = 2.4 K), β-WB (T{sub C} = 2.0 K), α-WB (T{sub C} = 4.3 K), W{sub 2}B{sub 4} (T{sub C} = 5.4 K), Re{sub 7}B{sub 3} (T{sub C} = 2.4 K). A relationship between the superconducting properties

  12. Synthesis by plasma and characterization of compounds derived from polyacetylene

    Vasquez O, M.

    2004-01-01

    This work presents a study on, the synthesis by plasma and the characterization of an aliphatic conjugated polymer, polyacetylene-chlorinated (Pac), and two aromatic polymers, Poly pyrrole (P Py-Cl) and Poly thiophene (Pth-Cl) synthesized with chlorine and the electrical conductivity. The last two polymers were synthesized to compare the chlorine-polymer interaction in aliphatic and aromatic polymers synthesized by plasma and their repercussion on the electrical transport of charges in the material. The structure and morphology of the polymers were studied using scanning electron microscopy (Sem), energy dispersive spectroscopy (EDS), infrared spectroscopy (Ft-IR), conductivity analysis and X-Ray photon spectroscopy (XPS). The results showed that Pac is soluble in acetone and other organic solvents, which indicates a low proportion of crosslinking in the polymers. This point is important because the crosslinking reduces the electrical conductivity in the material. The Pac conductivity is in the range of 1 x 10 -12 to 6 x 10 -4 S/cm in the internal of 35- 90% of relative humidity. A possible mechanism for the transport of electrical charges in Pac is by means of the double and simple conjugated bonds in the polymers. Pth-Cl and P Py-Cl present electric conductivity in the interval of 9 x 10 -5 to 1 x 10 -2 S/cm and show a great dependence on the relative humidity. The chlorine addition in these polymers was through simultaneous polymerization with chloroform. This last compound can decompose if the energy of the plasma is relatively high, and the fragments can link to the polymer in a hybrid process of copolymerization. An important point of this work is that the polymer is soluble, a difference of the obtained via plasma as the poli aniline, P Py-CI and Pth-Cl both studied in this work. If took in account that the Pac is single the monomer and that P Py-Cl and Pth-CI is affected by the chlorine that modifies the conductivity of the material, then Pac presents an

  13. Transition metal borides. Synthesis, characterization and superconducting properties

    Kayhan, Mehmet

    2013-01-01

    A systematic study was done on the synthesis and superconducting properties of metal rich transition metal borides. Five different binary systems were investigated including the boride systems of niobium, tantalum, molybdenum, tungsten and rhenium. High temperature solid state methods were used in order to synthesize samples of different transition metal borides of the composition M 2 B, MB, M 3 B 2 , MB 2 , and M 2 B 4 . The reactions were carried out in three different furnaces with different sample containers: the electric arc (copper crucible), the high frequency induction furnace (boron nitride, tantalum or glassy carbon crucibles), and the conventional tube furnace (sealed evacuated quartz ampoules). The products obtained were characterized with X-ray powder diffractometry, scanning electron microscopy and energy-dispersive X-ray spectroscopy. Phase analyses and crystal structure refinements using the Rietveld method and based on structure models known from literature were performed. A neutron diffraction measurement was done for W 2 B 4 to allow for a complete crystal structure determination, because of the presence of a heavy element like tungsten and a light element like boron that made it difficult to determine the accurate determination of the boron atom positions and occupancies from X-ray data. A new structure model for W 2 B 4 was proposed. Magnetic measurements in a SQUID magnetometer down to temperatures as low as 1.8 K were performed to several of the products in order to see if the transition metal borides become superconducting at low temperatures, and the results were compared with data from literature. Superconducting properties were found for the following compounds: NbB 2 (T C = 3.5 K), β-MoB (T C = 2.4 K), β-WB (T C = 2.0 K), α-WB (T C = 4.3 K), W 2 B 4 (T C = 5.4 K), Re 7 B 3 (T C = 2.4 K). A relationship between the superconducting properties and the compositional and structural features was discussed for metal diborides. Also it was

  14. Synthesis and characterization of TEP-EDTA-regulated bioactive hydroxyapatite

    Haders, Daniel Joseph, II

    Hydroxyapatite (HA), Ca10(PO4)6(OH) 2, the stoichiometric equivalent of the ceramic phase of bone, is the preferred material for hard tissue replacement due to its bioactivity. However, bioinert metals are utilized in load-bearing orthopedic applications due to the poor mechanical properties of HA. Consequently, attention has been given to HA coatings for metallic orthopedic implants to take advantage of the bioactivity of HA and the mechanical properties of metals. Commercially, the plasma spray process (PS-HA) is the method most often used to deposit HA films on metallic implants. Since its introduction in the 1980's, however, concerns have been raised about the consequences of PS-HA's low crystallinity, lack of phase purity, lack of film-substrate chemical adhesion, passivation properties, and difficulty in coating complex geometries. Thus, there is a need to develop inexpensive reproducible next-generation HA film deposition techniques, which deposit high crystallinity, phase pure, adhesive, passivating, conformal HA films on clinical metallic substrates. The aim of this dissertation was to intelligently synthesize and characterize the material and biological properties of HA films on metallic substrates synthesized by hydrothermal crystallization, using thermodynamic phase diagrams as the starting point. In three overlapping interdisciplinary studies the potential of using ethylenediamine-tetraacetic acid/triethyl phosphate (EDTA/TEP) doubly regulated hydrothermal crystallization to deposit HA films, the TEP-regulated, time-and-temperature-dependent process by which films were deposited, and the bioactivity of crystallographically engineered films were investigated. Films were crystallized in a 0.232 molal Ca(NO3)2-0.232 molal EDTA-0.187 molal TEP-1.852 molal KOH-H2O chemical system at 200°C. Thermodynamic phase diagrams demonstrated that the chosen conditions were expected to produce Ca-P phase pure HA, which was experimentally confirmed. EDTA regulation of

  15. Synthesis, characterization and mechanistic insights of mycogenic iron oxide nanoparticles

    Bhargava, Arpit; Jain, Navin; Manju Barathi L [Birla Institute of Technology and Science, Centre for Biotechnology, Department of Biological Sciences (India); Akhtar, Mohd Sayeed [Jimma University, Department of Applied Microbiology, College of Natural Sciences (Ethiopia); Yun, Yeoung-Sang [Chonbuk National University, Division of Environmental and Chemical Engineering (Korea, Republic of); Panwar, Jitendra, E-mail: drjitendrapanwar@yahoo.co.in [Birla Institute of Technology and Science, Centre for Biotechnology, Department of Biological Sciences (India)

    2013-11-15

    In the present study, extracellular synthesis of iron oxide nanoparticles (IONPs) was achieved using Aspergillus japonicus isolate AJP01. The isolate demonstrated its ability to hydrolyze the precursor salt solution, a mixture of iron cyanide complexes, under ambient conditions. Hydrolysis of these complexes released ferric and ferrous ions, which underwent protein-mediated coprecipitation and controlled nucleation resulting in the formation of IONPs. Transmission electron microscopy, selected area electron diffraction pattern, energy dispersive spectroscopy and grazing incidence X-ray diffraction analysis confirmed the mycosynthesis of IONPs. The synthesized particles were cubic in shape with a size range of 60–70 nm with crystal structure corresponding to magnetite. Scanning electron microscopy analysis revealed the absence of IONPs on fungal biomass surface, indicating the extracellular nature of synthesis. Fourier transform infrared spectroscopy confirmed the presence of proteins on as-synthesised IONPs, which may confer their stability. Preliminary investigation indicated the role of proteins in the synthesis and stabilization of IONPs. On the basis of present findings, a probable mechanism for synthesis of IONPs is suggested. The simplicity and versatility of the present approach can be utilized for the synthesis of other nanomaterials.

  16. Template-Assisted Synthesis and Characterization of Passivated Nickel Nanoparticles

    Al-Omari IA

    2010-01-01

    Full Text Available Abstract Potential applications of nickel nanoparticles demand the synthesis of self-protected nickel nanoparticles by different synthesis techniques. A novel and simple technique for the synthesis of self-protected nickel nanoparticles is realized by the inter-matrix synthesis of nickel nanoparticles by cation exchange reduction in two types of resins. Two different polymer templates namely strongly acidic cation exchange resins and weakly acidic cation exchange resins provided with cation exchange sites which can anchor metal cations by the ion exchange process are used. The nickel ions which are held at the cation exchange sites by ion fixation can be subsequently reduced to metal nanoparticles by using sodium borohydride as the reducing agent. The composites are cycled repeating the loading reduction cycle involved in the synthesis procedure. X-Ray Diffraction, Scanning Electron Microscopy, Transmission Electron microscopy, Energy Dispersive Spectrum, and Inductively Coupled Plasma Analysis are effectively utilized to investigate the different structural characteristics of the nanocomposites. The hysteresis loop parameters namely saturation magnetization and coercivity are measured using Vibrating Sample Magnetometer. The thermomagnetization study is also conducted to evaluate the Curie temperature values of the composites. The effect of cycling on the structural and magnetic characteristics of the two composites are dealt in detail. A comparison between the different characteristics of the two nanocomposites is also provided.

  17. Synthesis and structures of a pincer-type rhodium(iii) complex: reactivity toward biomolecules.

    Milutinović, Milan M; Bogojeski, Jovana V; Klisurić, Olivera; Scheurer, Andreas; Elmroth, Sofi K C; Bugarčić, Živadin D

    2016-10-04

    A novel rhodium(iii) complex [Rh III (H 2 L tBu )Cl 3 ] (1) (H 2 L tBu = 2,6-bis(5-tert-butyl-1H-pyrazol-3-yl)pyridine) containing a pincer type, tridentate nitrogen-donor chelate system was synthesized. Single crystal X-ray structure analysis revealed that 1 crystallizes in the orthorhombic space group Pbcn with a = 20.7982(6), b = 10.8952(4), c = 10.9832(4) Å, V = 2488.80(15) Å 3 , and eight molecules in the unit cell. The rhodium center in the complex [Rh III (H 2 L tBu )Cl 3 ] (1) is coordinated in a slightly distorted octahedral geometry by the tridentate N,N,N-donor and three chloro ligands, adopting a mer arrangement with an essentially planar ligand skeleton. Due to the tridentate coordination of the N,N,N-donor, the central nitrogen atom N1 is located closer to the Rh III center. The reactivity of the synthesized complex toward small biomolecules (l-methionine (l-Met), guanosine-5'-monophosphate (5'-GMP), l-histidine (l-His) and glutathione (GSH)) and to a series of duplex DNAs and RNA was investigated. The order of reactivity of the studied small biomolecules is: 5'-GMP > GSH > l-Met > l-His. Duplex RNA reacts faster with the [Rh III (H 2 L tBu )Cl 3 ] complex than duplex DNA, while shorter duplex DNA (15mer GG) reacts faster compared with 22mer GG duplex DNA. In addition, a higher reactivity is achieved with a DNA duplex with a centrally located GG-sequence than with a 22GTG duplex DNA, in which the GG-sequence is separated by a T base. Furthermore, the interaction of this metal complex 1 with calf thymus DNA (CT-DNA) and bovine serum albumin (BSA) was examined by absorption (UV-Vis) and emission spectral studies (EthBr displacement studies). Overall, the studied complex exhibited good DNA and BSA interaction ability.

  18. Synthesis and photophysical characterizations of thermal-stable naphthalene benzimidazoles.

    Erten-Ela, Sule; Ozcelik, Serdar; Eren, Esin

    2011-07-01

    Microwave-assisted synthesis, photophysical and electrochemical properties of thermal-stable naphthalene benzimidazoles and naphthalimides are studied in this paper. Microwave-assisted synthesis of naphthalene benzimidazoles provide higher yields than the conventional thermal synthesis. Comparative photophysical properties of naphthalene benzimidazoles and naphthalimides are revealed that conjugation of electron-donating group onto naphthalimide moiety increases fluorescence quantum yields. Fluorophore-solvent interactions are also investigated using Lippert-Mataga equation for naphthalimides and naphthalene benzimidazoles. Thermal stabilities of naphthalene benzimidazoles are better than naphthalimides due to increased aromaticity. The experimental E(LUMO) levels of naphthalene benzimidazoles are found to be between 3.15 and 3.28 eV. Therefore, naphthalene benzimidazole derivatives consisting of anchoring groups are promising materials in organic dye sensitized solar cells. © Springer Science+Business Media, LLC 2011

  19. Synthesis and characterization of [Ru(η6-C6Me6)Cl2(CNPy)] and [Cl2(η6-C6Me6)Ru-(μ-CNPy)-Ru(η6-C6Me6)Cl2] and reactivity of [Ru(η6-C6Me6)Cl2(CNPy)] with various bases

    Pandey, D.S.; Sahay, A.N.; Agarwala, U.C.

    1996-01-01

    Reactions of [(Ru(η 6 -C 6 Me 6 )Cl 2 ) 2 ] with 4-cyanopyridine leads to the formation of neutral mono and dimeric complexes viz., [Ru(η 6 C 6 Me 6 )Cl 2 (CNPy)] (I) and [Cl 2 (η 6 -C 6 Me 6 ) Ru-(μ-CNPy)-Ru(η 6 -C 6 Me 6 )Cl 2 ] (II). Complex (I) undergoes metathetical reactions with EPh 3 (E=P, As and Sb) and N-donor heterocyclic bases yielding corresponding substitutional products which have been characterized by elemental analyses and spectroscopic: (IR, UV/vis, 1 H and 13 C NMR) studies. (author). 21 refs., 1 tab

  20. Biobased functional polyesters for coating applications: Synthesis, characterization and application

    Noordover, B.A.J.; Duchateau, R.; Koning, C.E.; Benthem, van R.A.T.M.; Ming, W.; Haveren, van J.; Es, van D.S.

    2007-01-01

    Thermosetting coating systems contain polyesters as binders. A crucial property of these polymers is their functionality. During coating application, the polyesters are cross-linked in situ, which means that each polymer chain needs a sufficient no. of reactive end-groups. Renewable monomers are

  1. Nitrogen doped carbon nanotubes : synthesis, characterization and catalysis

    van Dommele, S.

    2008-01-01

    Nitrogen containing Carbon Nanotubes (NCNT) have altered physical- and chemical properties with respect to polarity, conductivity and reactivity as compared to conventional carbon nanotubes (CNT) and have potential for use in electronic applications or catalysis. In this thesis the incorporation of

  2. Synthesis and Characterization of Block Copolymers with Unique Chemical Functionalities and Entropically-Hindering Moieties

    2017-08-14

    methanol as a function of chemistry , morphology and hydration levels. Accomplishments: This section is included in the "upload" section. Training...Copolymer Blend Membranes.” In Press, Polymer Engineering and Science, DOI: 10.1002 /pen.24508, 2017. 5. M. Pérez-Pérez and D. Suleiman. “Synthesis and...Synthesis and Characterization of Sulfonated Amine Block Copolymers for Energy Efficient Applications". Chemical Engineering Symposium, University of

  3. Chemical synthesis, characterization studies and reactivity of a catalytic material based on ZrO{sub 2}-H{sub 3}PW{sub 12}O{sub 40}; Sintesis quimica, estudios de caracterizacion y reactividad de un material catalitico a base de ZrO{sub 2}-H{sub 3}PW{sub 12}O{sub 40}

    Hernandez Enriquez, Juan Manuel; Garcia Alamilla, Ricardo; Paramo Garcia, Ulises; Rodrigo, Rebeca Silva [Instituto Tecnologico de Ciudad Madero, Tamaulipas (Mexico). Division de Estudios de Posgrado e Investigacion; Garcia Serrano, Luz Arcelia, E-mail: jmanuelher@hotmail.com [Instituto Politecnico Nacional, Mexico, D.F. (Mexico). Centro Interdisciplinario de Investigaciones y Estudios sobre Medio Ambiente

    2013-10-01

    In this work, the preparation and characterization of materials such as zirconium oxide (ZrO{sub 2}) and phosphotungstic acid promoted zirconium oxide (ZrO{sub 2}-H{sub 3}PW{sub 12}O{sub 40}) is presented. Physico-chemical characterization results showed that addition of H{sub 3}PW{sub 12}O{sub 40} acted as both a textural and chemical promoter of zirconium oxide. The incorporation of phosphotungstic acid into the ZrO{sub 2} matrix delayed the sintering of the material and stabilized ZrO{sub 2} in the tetragonal phase. ZrO{sub 2} acidity was also enhanced, developing strong acid sites on its surface. The Pt/ZrO{sub 2}-H{sub 3}PW{sub 12}O{sub 40} catalyst was active for n-pentane isomerization at 250 deg C, exhibiting high selectivity to iso-pentane (95%). This result is probably due to its suitable acidity (author)

  4. Theoretical study for pyridinium-based ionic liquid 1-ethylpyridinium trifluoroacetate: synthesis mechanism, electronic structure, and catalytic reactivity.

    Zhu, Xueying; Cui, Peng; Zhang, Dongju; Liu, Chengbu

    2011-07-28

    By performing density functional theory calculations, we have studied the synthesis mechanism, electronic structure, and catalytic reactivity of a pyridinium-based ionic liquid, 1-ethylpyridinium trifluoroacetate ([epy](+)[CF(3)COO](-)). It is found that the synthesis of the pyridinium salt follows a S(N)2 mechanism. The electronic structural analyses show that multiple H bonds are generally involved in the pyridinium-based ionic liquid, which may play a decisive role for stabilizing the ionic liquid. The cation-anion interaction mainly involves electron transfer between the lone pair of the oxygen atom in the anion and the antibonding orbital of the C*-H bond (C* denotes the carbon atom at the ortho-position of nitrogen atom in the cation). This present work has also given clearly the catalytic mechanism of [epy](+)[CF(3)COO](-) toward to the Diels-Alder (D-A) reaction of acrylonitrile with 2-methyl-1,3-butadiene. Both the cation and anion are shown to play important roles in promoting the D-A reaction. The cation [epy](+), as a Lewis acid, associates the C≡N group by C≡N···H H bond to increase the polarity of the C═C double bond in acrylonitrile, while the anion CF(3)COO(-) links with the methyl group in 2-methyl-1,3-butadiene by C-H···O H bond, which weakens the electron-donating capability of methyl and thereby lowers the energy barrier of the D-A reaction. The present results are expected to provide valuable information for the design and application of pyridinium-based ionic liquids. © 2011 American Chemical Society

  5. Raman spectroscopy for characterizing and determining the pozzolanic reactivity of fly ashes

    Garg, Nishant

    The efficacy and potential of Raman spectroscopy in characterization of a commercial Ordinary Portland Cement (OPC) and three fly ashes (FA's), and their evolving hydration products were studied in this Master's thesis work. While there have been several studies focusing on the application of Raman spectroscopy to synthetic, pure samples, work on commercial cementitious systems is scarce. This work covers this gap by evaluating mixtures containing cements and fly ashes. The study first involved determination followed by establishment of instrumental configuration and testing parameters optimum for studying cementitious materials both in the dry and wet form. It was found that by tweaking several parameters, collection methodologies and analysis techniques, improved, representative and reproducible data could be obtained. Mapping a representative area to determine the spatial distribution and concentration of sulfates and hydroxides on sample surfaces was found to be the most effective way to study these complex and heterogeneous systems. The Raman dry analysis of OPC and three different FA's of varying calcium contents and reactivity was able to identify the major mineralogical phases in these binders and the results were in correlation with the X-ray diffraction data. The observed calcium and sulfate phases and their relative concentration also agreed well with the supplementary compositional data obtained from X-ray fluorescence and Atomic absorption spectrometry. The wet analysis of pastes prepared with 100% OPC and 50%OPC+50%FA(1,2,3) followed the hydration process of the systems for 56 days (0, 0.2, 2, 4, 8, 12, 16, 20, 24, 48, 72 hours, 7, 14, 21, 28, and 56 days). Consistency of trends in the hydration mechanism of such pastes was only obtained when studies were focused on narrow wavenumber ranges: 950--1050 cm-1 for evolution of sulfates and 3600--3700cm-1 for evolution of hydroxides. Gradual disappearance of Gypsum with a parallel formation of Ettringite

  6. Synthesis, Crystal structure and Characterization of a New Oxalate ...

    in a slightly distorted octahedral environment, by two O atoms from two water molecules and four O atoms of two oxalate anions acting as chelating ligands. ... component for building up supramolecular systems and for participating in hydrogen bonding ... heating rate of 10◦C min−1. 2.2 Synthesis of the complex. Aqueous ...

  7. Metathesis synthesis and characterization of complex metal fluoride ...

    Administrator

    V MANIVANNAN*, P PARHI and JONATHAN W KRAMER. Department of Mechanical Engineering, Campus Delivery 1374, Colorado State University, Fort Collins,. CO 80523, USA. MS received 30 April 2008. Abstract. Metathesis synthesis of complex metal fluorides using mechanochemical activation has been reported.

  8. Synthesis and characterization of 4-[(E)-(-2,5 ...

    The synthesis of 4-[(E)-(-2,5- dimethoxybenzylidene)amino] benzoic acid. Schiff base, SBDAB was carried out inorder to determine its inhibitory efficiency at higher temperature using weight loss and gasometric techniques. The results showed that the inhibition efficiency of the studied Schiff base increased with increase in ...

  9. synthesis, characterization an complexes with schiff base co

    userpc

    active Ru(II) complexes with coordinating Schiff base were synthesiz lemental ... synthesis and stability of Schiff bases wh ... chelates with anticancer activity have also ..... iron.Inorg. Chem,23(1), 3-10. Kostova, I.; Sasa, L.(2013). Advances in.

  10. Synthesis, characterization and emission properties of quinolin-8 ...

    Unknown

    chelated ruthenium organometallics. BIKASH KUMAR PANDA. Department of Inorganic ... Ruthenium organometallics; quinolin-8-olato chelation; emission properties; trivalent ruthenium. 1. Introduction. There is continuing ... chem.istry of orthometallated ruthenium compounds is of current interest in the context of synthesis ...

  11. A simple synthesis and characterization of CuS nanocrystals

    Unknown

    Water-soluble CuS nanocrystals and nanorods were prepared by reacting copper acetate with thioacetamide in ... potential applications in solar cells, IR detectors and lubri- cation (Mane ... ted a solventless synthesis of Cu2S nanorods, by heating copper thiolate .... 2004 Nanoparticles: Building blocks for nano- technology ...

  12. Noble silver nanoparticles (AgNPs) synthesis and characterization ...

    Nanotechnology is rapidly growing with nanoparticles produced and utilized in a wide range of pharmaceutical and commercial products throughout the world. In this study, fig (Ficus carica) leaf extracts were used for ecofriendly extracellular synthesis of stable silver nanoparticles (AgNPs) by treating an aqueous silver ...

  13. Synthesis and characterization of new meso-substituted ...

    WINTEC

    tems. 10. Their ability to carry out the reactions rather unusual in organic chemistry has been the object of intensive investigations aiming to utilize them as a model compounds for biological systems and as catalysts. 11. Therefore, the synthesis of well defined meso-substituted unsymmetrical porphyrin deriva- tives (A3B) is ...

  14. Synthesis of an Albendazole Metabolite: Characterization and HPLC Determination

    Mahler, Graciela; Davyt, Danilo; Gordon, Sandra; Incerti, Marcelo; Nunez, Ivana; Pezaroglo, Horacio; Scarone, Laura; Serra, Gloria; Silvera, Mauricio; Manta, Eduardo

    2008-01-01

    In this laboratory activity, students are introduced to the synthesis of an albendazole metabolite obtained by a sulfide oxidation reaction. Albendazole as well as its metabolite, albendazole sulfoxide, are used as anthelmintic drugs. The oxidation reagent is H[subscript 2]O[subscript 2] in acetic acid. The reaction is environmental friendly,…

  15. Reactive physical vapor deposition of TixAlyN: Integrated plasma-surface modeling characterization

    Zhang Da; Schaeffer, J.K.

    2004-01-01

    Reactive physical vapor deposition (RPVD) has been widely applied in the microelectronic industry for producing thin films. Fundamental understanding of RPVD mechanisms is needed for successful process development due to the high sensitivity of film properties on process conditions. An integrated plasma equipment-target nitridation modeling infrastructure for RPVD has therefore been developed to provide mechanistic insights and assist optimal process design. The target nitridation model computes target nitride coverage based on self-consistently derived plasma characteristics from the plasma equipment model; target sputter yields needed in the plasma equipment model are also self-consistently derived taking into account the yield-suppressing effect from nitridation. The integrated modeling infrastructure has been applied to investigating RPVD processing with a Ti 0.8 Al 0.2 compound target and an Ar/N 2 gas supply. It has been found that the process produces athermal metal neutrals as the primary deposition precursor. The metal stoichiometry in the deposited film is close to the target composition due to the predominance of athermal species in the flux that reaches the substrate. Correlations between process parameters (N 2 flow, target power), plasma characteristics, surface conditions, and deposition kinetics have been studied with the model. The deposition process is characterized by two regimes when the N 2 flow rate is varied. When N 2 is dilute relative to argon, target nitride coverage increases rapidly with increasing N 2 flow. The sputter yield and deposition rate consequently decrease. For less dilute N 2 mixtures, the sputter yield and deposition rate are stable due to the saturation of target nitridation. With increasing target power, the electron density increases nearly linearly while the variation of N generation is much smaller. Target nitridation and its suppression of the sputter yield saturate at high N 2 flow rendering these parameters

  16. Quantitative characterization of silicon- and aluminium oxynitride films produced by reactive dc-magnetron sputtering

    Dreer, S.

    2000-05-01

    The deposition of aluminum and silicon oxynitride films by reactive dc-magnetron sputtering was systematically planned by design of experiments, carried out and evaluated with the application of specialized statistics software. The influence of the deposition parameters on the resulting films was evaluated by multiple regression analysis. With the obtained data a model of the deposition process for the quantitative prediction of the deposition parameters necessary to obtain films with desired composition was built. This is also of technological importance, since the physical properties of the films strongly depend on their composition. Furthermore, the long term repeatability of the deposition process was implemented into the model. A precise and economic way for quantitative bulk analysis of silicon/aluminum, oxygen and nitrogen based on EPMA was presented and the use of data gained by the latter method is discussed for the calculation of relative sensitivity factors for SIMS and hf-SNMS. Advantages and disadvantages of SIMS, hf-SNMS, hf-GD-OES, and sputter AES were compared. The combination FT-IR/EPMA/SIMS at present offers the best possibility for a quantitative bulk and in depth distribution analysis of such films in the range of 20 to 1000 nm thickness. The films were also characterized by XRD and PAA. The refractive index and the growth rate of the films were determined by spectroscopic ellipsometry. With indentation by a nano hardness tester the hardness and the Young's modulus of the films were obtained. The results of these measurements were evaluated by statistical software. The dependencies of the physical properties on the deposition parameters and on the film thickness were evaluated and quantified. Furthermore, the dependencies of the physical properties on the film composition represented by the oxygen content were evaluated. (author)

  17. Characterizing the malaria rural-to-urban transmission interface: The importance of reactive case detection.

    Karen Molina Gómez

    2017-07-01

    Full Text Available Reported urban malaria cases are increasing in Latin America, however, evidence of such trend remains insufficient. Here, we propose an integrated approach that allows characterizing malaria transmission at the rural-to-urban interface by combining epidemiological, entomological, and parasite genotyping methods.A descriptive study that combines active (ACD, passive (PCD, and reactive (RCD case detection was performed in urban and peri-urban neighborhoods of Quibdó, Colombia. Heads of households were interviewed and epidemiological surveys were conducted to assess malaria prevalence and identify potential risk factors. Sixteen primary cases, eight by ACD and eight by PCD were recruited for RCD. Using the RCD strategy, prevalence of 1% by microscopy (6/604 and 9% by quantitative polymerase chain reaction (qPCR (52/604 were found. A total of 73 houses and 289 volunteers were screened leading to 41 secondary cases, all of them in peri-urban settings (14% prevalence. Most secondary cases were genetically distinct from primary cases indicating that there were independent occurrences. Plasmodium vivax was the predominant species (76.3%, 71/93, most of them being asymptomatic (46/71. Urban and peri-urban neighborhoods had significant sociodemographic differences. Twenty-four potential breeding sites were identified, all in peri-urban areas. The predominant vectors for 1,305 adults were Anopheles nuneztovari (56,2% and An. Darlingi (42,5%. One An. nuneztovari specimen was confirmed naturally infected with P. falciparum by ELISA.This study found no evidence supporting the existence of urban malaria transmission in Quibdó. RCD strategy was more efficient for identifying malaria cases than ACD alone in areas where malaria transmission is variable and unstable. Incorporating parasite genotyping allows discovering hidden patterns of malaria transmission that cannot be detected otherwise. We propose to use the term "focal case" for those primary cases that

  18. Synthesis and characterization of highly triboluminescent doped europium tetrakis compounds

    Fontenot, Ross S.; Hollerman, William A.; Bhat, Kamala N.; Aggarwal, Mohan D.

    2012-01-01

    One of the most intriguing properties involving crystals is their ability to emit light when fractured. While this property was discovered over 200 years ago, no one has ever been able to come up with a complete theory that can predict the physical principles associated with triboluminescence. However, this has not stopped scientists from coming up with various uses for these materials. One such application is to use these materials as the active element for smart impact sensors that can warn of catastrophic impacts. If these sensors are to become a reality however, the material must emit a bright light when fractured. One of the brightest triboluminescent materials found thus far is europium dibenzoylmethide triethylammonium (EuD 4 TEA). This material was discovered by Hurt in 1966 and is bright enough to be seen in daylight. In 2011, the authors discovered that synthesizing EuD 4 TEA using europium nitrate instead of chloride significantly increased the triboluminescence yield and made the synthesis much easier and more consistent. However, to date, there are few investigations into the effects of dopants on the triboluminescence of EuD 4 TEA. This paper reports the investigation of the effects of various dopants on: (1) The triboluminescent light yield, (2) Crystal size and structure, (3) Synthesis time, and (4) Prompt decay time. Results show that inclusion of dopants during synthesis increases the triboluminescence emission of EuD 4 TEA by 55%, significantly reduces the synthesis time, and controls the decay time. All of these properties can be useful for constructing the first prototype of a customized impact sensor. - Highlights: ► Doped europium dibenzoylmethide triethylammonium (EuD 4 TEA) was synthesized. ► Effects of dopants was studied from EuD 4 TEA during low velocity (<10 m/s) impacts. ► The triboluminescent light yield, decay time, and synthesis time were measured. ► A specially-built drop tower was developed to measure triboluminescence

  19. Synthesis and characterization of aminated perfluoro polymer electrolytes

    Page-Belknap, Zachary Stephan Glenn

    Polymer electrolytes have been developed for use in anion exchange membrane fuel cells for years. However, due to the highly corrosive environment within these fuel cells, poor chemical stability of the polymers and low ion conductivity have led to high development costs and thus prevention from widespread commercialization. The work in this study aims to provide a solution to these problems through the synthesis and characterization of a novel polymer electrolyte. The 800 EW 3M PFSA sulfonyl fluoride precursor was aminated with 3-(dimethylamino)-1-propylamine to yield a functional polymer electrolyte following quaternization, referred to in this work as PFSa-PTMa. 1 M solutions of LiPF6, HCL, KOH, NaOH, CsOH, NaHCO3 and Na2CO3 were used to exchange the polymer to alternate counterion forms. Chemical structure analysis was performed using both FT and ATR infrared spectroscopy to confirm sulfonyl fluoride replacement and the absence of sulfonic acid sites. Mechanical testing of the polymer, following counterion exchange with KOH, at saturated conditions and 60 ºC exhibited a tensile strength of 13 +/- 2.0 MPa, a Young's modulus of 87 +/- 16 MPa and a degree of elongation reaching 75% +/- 9.1%, which indicated no mechanical degradation following exposure to a highly basic environment. Conductivities of the polymer in the Cl- and OH- counterion forms at saturated conditions and 90 ºC were observed at 26 +/- 8.0 mS cm-1 and 1.1 +/- 0.1 mS cm-1, respectively. OH- conductivities were slightly above those observed for CO32- and HCO 3- counterions at the same conditions, 0.63 +/- 0.18 and 0.66 +/- 0.21 mS cm-1 respectively. The ion exchange capacity (IEC) of the polymer in the Cl- counterion form was measured via titration at 0.57 meq g-1 which correlated to 11.2 +/- 0.10 water molecules per ion site when at 60ºC and 95% relative humidity. The IEC of the polymer in the OH- counterion form following titration expressed nearly negligible charge density, less than 0.01 meq

  20. Synthesis and characterization of iron based nanoparticles for novel applications

    Khurshid, Hafsa

    The work in this thesis has been focused on the fabrication and characterization of iron based nanoparticles with controlled size and morphology with the aim: (i) to investigate their properties for potential applications in MICR toners and biomedical field and (ii) to study finite size effects on the magnetic properties of the nanoparticles. For the biomedical applications, core/shell structured iron/iron-oxide and hollow shell nanoparticles were synthesized by thermal decomposition of iron organometallic compounds [Fe(CO)5] at high temperature. Core/shell structured iron/iron-oxide nanoparticles have been prepared in the presence of oleic acid and oleylamine. Particle size and composition was controlled by varying the reaction parameters during synthesis. The as-made particles are hydrophobic and not dispersible in water. Water dispersibility was achieved by ligand exchange a with double hydrophilic diblock copolymer. Relaxometery measurements of the transverse relaxation time T2 of the nanoparticles solution at 3 Tesla confirm that the core/shell nanoparticles are an excellent MRI contrast agent using T2 weighted imaging sequences. In comparison to conventionally used iron oxide nanoparticles, iron/iron-oxide core/shell nanoparticles offer four times stronger T2 shortening effect at comparable core size due to their higher magnetization. The magnetic properties were studied as a function of particle size, composition and morphology. Hollow nanostructures are composed of randomly oriented grains arranged together to make a shell layer and make an interesting class of materials. The hollow morphology can be used as an extra degree of freedom to control the magnetic properties. Owing to their hollow morphology, they can be used for the targeted drug delivery applications by filling the drug inside their cavity. For the magnetic toners applications, particles were synthesized by chemically reducing iron salt using sodium borohydride and then coated with polyethylene

  1. Advances in acrylic-alkyd hybrid synthesis and characterization

    Dziczkowski, Jamie

    2008-10-01

    performance. Reversible-addition fragmentation polymerization techniques were employed to create a new class of acrylic-alkyd hybrid materials. Medium and long oil alkyds made from the monoglyceride process using soybean oil, glycerol, and phthalic anhydride were modified with a RAFT chain transfer agent. The alkyd macro-RAFT agents were reached by end-capping a medium oil soya-based alkyd with a carboxy-functional trithiocarbonate. The alkyd macro-RAFT agents were then used to create acrylic-alkyd block structures by polymerizing different acrylic monomers, including both acrylates and methacrylates in the presence of the macro-RAFT agent and 2, 2'-azobisisobutyronitrile (AIBN). Co-acrylic segments were reached by complete polymerization of one monomer followed by the addition of a second monomer and additional free radical initiator. The alkyds, macro-RAFT agents and, acrylic-alkyd blocks were characterized by size-exclusion chromatography (SEC), FTIR, and 1H-NMR. Pseudo-first-order kinetics behavior and conversion vs. molecular weight plots show that the RAFT-mediated reaction afforded a more controlled process for the synthesis of acrylated-alkyd materials. Preliminary coatings tests showed that material properties of acrylated-alkyds achieved by RAFT polymerization exhibit good overall coatings properties including adhesion, gloss, hardness, and impact resistance.

  2. Polar red-emitting rhodamine dyes with reactive groups: synthesis, photophysical properties, and two-color STED nanoscopy applications.

    Kolmakov, Kirill; Wurm, Christian A; Meineke, Dirk N H; Göttfert, Fabian; Boyarskiy, Vadim P; Belov, Vladimir N; Hell, Stefan W

    2014-01-03

    The synthesis, reactivity, and photophysical properties of new rhodamines with intense red fluorescence, two polar residues (hydroxyls, primary phosphates, or sulfonic acid groups), and improved hydrolytic stability of the amino-reactive sites (NHS esters or mixed N-succinimidyl carbonates) are reported. All fluorophores contain an N-alkyl-1,2-dihydro-2,2,4-trimethylquinoline fragment, and most of them bear a fully substituted tetrafluoro phenyl ring with a secondary carboxamide group. The absorption and emission maxima in water are in the range of 635-639 and 655-659 nm, respectively. A vastly simplified approach to red-emitting rhodamines with two phosphate groups that are compatible with diverse functional linkers was developed. As an example, a phosphorylated dye with an azide residue was prepared and was used in a click reaction with a strained alkyne bearing an N-hydroxysuccinimid (NHS) ester group. This method bypasses the undesired activation of phosphate groups, and gives an amphiphilic amino-reactive dye, the solubility and distribution of which between aqueous and organic phases can be controlled by varying the pH. The presence of two hydroxyl groups and a phenyl ring with two carboxyl residues in the dyes with another substitution pattern is sufficient for providing the hydrophilic properties. Selective formation of a mono-N-hydroxysuccinimidyl ester from 5-carboxy isomer of this rhodamine is reported. The fluorescence quantum yields varied from 58 to 92% for free fluorophores, and amounted to 18-64% for antibody conjugates in aqueous buffers. The brightness and photostability of these fluorophores facilitated two-color stimulated emission depletion (STED) fluorescence nanoscopy of biological samples with high contrast and minimal background. Selecting a pair of fluorophores with absorption/emission bands at 579/609 and 635/655 nm enabled two-color channels with low cross-talk and negligible background at approximately 40 nm resolution. Copyright

  3. Synthesis of self-assembled Ge nano crystals employing reactive RF sputtering

    Hernandez H, A. [Universidad Autonoma del Estado de Hidalgo, Escuela Superior de Apan, Calle Ejido de Chimalpa Tlalayote s/n, Col. Chimalpa, Apan, Hidalgo (Mexico); Hernandez H, L. A. [IPN, Escuela Superior de Fisica y Matematicas, San Pedro Zacatenco, 07730 Ciudad de Mexico (Mexico); Monroy, B. M.; Santana R, G. [UNAM, Instituto de Investigaciones en Materiales, Apdo. Postal 70-360, 04510 Ciudad de Mexico (Mexico); Santoyo S, J.; Gallardo H, S. [IPN, Centro de Investigacion y de Estudios Avanzados, Departamento de Fisica, Apdo. Postal 14740, 07300 Ciudad de Mexico (Mexico); Marquez H, A. [Universidad de Guanajuato, Campus Irapuato-Salamanca, Departamento de Ingenieria Agricola, Km. 9 Carretera Irapuato-Silao, 36500 Irapuato, Guanajuato (Mexico); Mani G, P. G.; Melendez L, M. [Universidad Autonoma de Ciudad Juarez, Instituto de Ingenieria y Tecnologia, Departamento de Fisica y Matematicas, 32310 Ciudad Juarez, Chihuahua (Mexico)

    2016-11-01

    This work presents the results of a simple methodology able to control crystal size, dispersion and spatial distribution of germanium nano crystals (Ge-NCs). It takes advantage of a self-assembled process taken place during the deposit of the system SiO{sub 2}/Ge/SiO{sub 2} by reactive RF sputtering. Nanoparticles formation is controlled mainly by the roughness of the first SiO{sub 2} layer buy the ulterior interaction of the interlayer with the top layer also play a role. Structural quality of germanium nano crystals increases with roughness and the interlayer thickness. The tetragonal phase of germanium is produced and its crystallographic quality improves with interlayer thickness and oxygen partial pressure. Room temperature photoluminescence emission without a post growth thermal annealing process indicates that our methodology produces a low density of non-radiative traps. The surface topography of SiO{sub 2} reference samples was carried out by atomic force microscopy. The crystallographic properties of the samples were studied by grazing incidence X-ray diffraction at 1.5 degrees carried out in a Siemens D-5000 system employing the Cu Kα wavelength. (Author)

  4. Synthesis and characterization of catalysts for the selective transformation of biomass-derived materials

    Ghampson, Isaac Tyrone

    The experimental work in this thesis focuses on generating catalysts for two intermediate processes related to the thermal conversion of lignocellulosic biomass: the synthesis and characterization of mesoporous silica supported cobalt catalysts for the Fischer-Tropsch reaction, and an exploration of the reactivity of bulk and supported molybdenum-based nitride catalysts for the hydrodeoxygenation (HDO) of guaiacol, a lignin model compound. The first section of the work details the synthesis of a series of silica-supported cobalt Fischer-Tropsch catalysts with pore diameters ranging from 2-23 nm. Detailed X-ray diffraction measurements were used to determine the composition and particle diameters of the metal fraction, analyzed as a three-phase system containing Cofcc, Cohcp and CoO particles. Catalyst properties were determined at three stages in catalyst history: (1) after the initial calcination step to thermally decompose the catalyst precursor into Co3O4, (2) after the hydrogen reduction step to activate the catalyst to Co and (3) after the FT reaction. From the study, it was observed that larger pore diameters supported higher turnover frequency; smaller pore diameters yielded larger mole fraction of CoO; XRD on post-reduction and post-FTS catalyst samples indicated significant changes in dispersivity after reduction. In the next section, the catalytic behaviors of unsupported, activated carbon-, alumina-, and SBA-15 mesoporous silica-supported molybdenum nitride catalysts were evaluated for the hydrodeoxygenation of guaiacol (2-methoxy phenol) at 300°C and 5 MPa. The nitride catalysts were prepared by thermal decomposition of bulk and supported ammonium heptamolybdate to form MoO 3 followed by nitridation in either flowing ammonia or a nitrogen/hydrogen mixture. The catalytic properties were strongly affected by the nitriding and purging treatment as well as the physical and chemical properties of support. The overall reaction was influenced by the

  5. Synthesis and characterization of cathode, anode and electrolyte materials for rechargeable lithium batteries

    Yang, Shoufeng

    Two new classes of cathode materials were studied: iron phosphate/sulfate materials and layered manganese oxides, both of which are low cost and had shown some potential. The first class of materials have poor conductivity and cyclability. I studied a number of methods for increasing the conductivity, and determined that grinding the material with carbon black was as effective as special in-situ coatings. The optimum carbon loading was determined to be between 6 and 15 wt%. Too much carbon reduces the volumetric energy density, whereas too little significantly increased cell polarization (reduced the rate of reaction). The kinetic and thermodynamic stability of LiFePO 4 was also studied and it was determined that over discharge protection will be needed as irreversible Li3PO4 can be formed at low potentials. A novel hydrothermal synthesis method was developed, but the significant level of Fe on the Li site reduces the reaction rate too much. In the case of the layered manganese oxide, cation substitution with Co and Ni is found to be effective in avoiding Jahn-Teller effects and improving electrochemistry. A wide range of tin compounds have been suggested as lithium storage media for advanced anode materials, as tin can store over 4 Li per Sn atom. Lithium hexafluorophosphate, LiPF6, is presently the salt of choice for LiCoO2 batteries, but it is expensive and dissolves some manganese compounds. The lithium bis(oxolato)borate (BOB) salt was recently reported, and I made a study of its use in cells with the LiFePO4 cathode and the tin anode. During its synthesis, it became clear that LiBOB is very reactive with many solvents, and these complexes were characterized to better understand this new material. In LiBOB the lithium is five coordinated, an unstable configuration for the lithium ion so that water and many other solvents rapidly react to make a six coordination. Only in the case of ethylene carbonate was the lithium found to be four coordinated. The Li

  6. Synthesis of Single-walled Carbon Nanotubes Coated with Thiol-reactive Gel via Emulsion Polymerization.

    Nagai, Yukiko; Tsutsumi, Yusuke; Nakashima, Naotoshi; Fujigaya, Tsuyohiko

    2018-06-15

    Single-walled carbon nanotubes (SWNTs) have unique near-infrared absorption and photoemission properties that are attractive for in vivo biological applications such as photothermal cancer treatment and bioimaging. Therefore, a smart functionalization strategy for SWNTs to create biocompatible surfaces and introduce various ligands to target active cancer cells without losing the unique optical properties of the SWNTs is strongly desired. This paper reports the de-sign and synthesis of a SWNT/gel hybrid containing maleimide groups, which react with various thiol compounds through Michael addition reactions. In this hybrid, the method called carbon nanotube micelle polymerization was used to non-covalently modify the surface of SWNTs with a cross-linked polymer gel layer. This method can form an extremely stable gel layer on SWNTs; such stability is essential for in vivo biological applications. The monomer used to form the gel layer contained a maleimide group, which was protected with furan in endo-form. The resulting hybrid was treated in water to induce deprotection via retro Diels-Alder reaction and then functionalized with thiol com-pounds through Michael addition. The functionalization of the hybrid was explored using a thiol-containing fluores-cent dye as a model thiol and the formation of the SWNT-dye conjugate was confirmed by energy transfer from the dye to SWNTs. Our strategy offers a promising SWNT-based platform for biological functionalization for cancer targeting, imaging, and treatment.

  7. Characterization of humic acid reactivity modifications due to adsorption onto α-Al 2O 3

    Janot, Noé mie; Reiller, Pascal E.; Zheng, Xing; Croue, Jean-Philippe; Benedetti, Marc F.

    2012-01-01

    in the supernatant and mass balance calculations, "titration curves" are experimentally proposed for the adsorbed fractions for the first time. These changes in reactivity to our opinion could explain the difficulty to model the behavior of ternary systems composed

  8. Synthesis of an oxo trialkyl tungsten fluoride complex and its dual reactivity with silica dehydroxylated at high temperature

    Merle, Nicolas

    2018-05-22

    The novel complex W (=O)Np3F has been prepared by fluorination of the corresponding chloride counterpart with AgBF4. The reactivity of this complex with silica dehydroxylated at 700 °C afforded a well-defined silica supported monopodal tungsten oxo trialkyl surface species (≡SiO)W (=O)Np3. The reaction proceeds both through silanolysis of the W-F bond and opening of a siloxane bridge, with formation of a Si-F fragment, thanks to the affinity of silicon for fluoride. The resulting surface species was characterized by elemental analysis, DRIFT, solid state NMR and EXAFS spectroscopy. This material presenting fluorine on its surface shows an enhanced catalytic activity in propylene self-metathesis compared to its monopodal counterpart (≡SiO)W (=O)Np3 (prepared from W (=O)Np3Cl) suggesting that the Si-F in a close vicinity to the W decreases the electron density of the W and thus increases its reactivity towards the olefinic substrate.

  9. Synthesis of an oxo trialkyl tungsten fluoride complex and its dual reactivity with silica dehydroxylated at high temperature

    Merle, Nicolas; Mazoyer, Etienne; Szeto, Kai C.; Rouge, Pascal; de Mallmann, Aimery; Berrier, Elise; Delevoye, Laurent; Gauvin, Ré gis M.; Nicholas, Christopher P.; Basset, Jean-Marie; Taoufik, Mostafa

    2018-01-01

    The novel complex W (=O)Np3F has been prepared by fluorination of the corresponding chloride counterpart with AgBF4. The reactivity of this complex with silica dehydroxylated at 700 °C afforded a well-defined silica supported monopodal tungsten oxo trialkyl surface species (≡SiO)W (=O)Np3. The reaction proceeds both through silanolysis of the W-F bond and opening of a siloxane bridge, with formation of a Si-F fragment, thanks to the affinity of silicon for fluoride. The resulting surface species was characterized by elemental analysis, DRIFT, solid state NMR and EXAFS spectroscopy. This material presenting fluorine on its surface shows an enhanced catalytic activity in propylene self-metathesis compared to its monopodal counterpart (≡SiO)W (=O)Np3 (prepared from W (=O)Np3Cl) suggesting that the Si-F in a close vicinity to the W decreases the electron density of the W and thus increases its reactivity towards the olefinic substrate.

  10. SYNTHESIS AND CHARACTERIZATION OF CANNABIS INDICA FIBER REINFORCED COMPOSITES

    Amar Singh Singha

    2011-04-01

    Full Text Available This paper reports on the synthesis of Cannabis indica fiber-reinforced composites using Urea-Resorcinol-Formaldehyde (URF as a novel matrix through compression molding technique. The polycondensation between urea, resorcinol, and formaldehyde in different molar ratios was applied to the synthesis of the URF polymer matrix. A thermosetting matrix based composite, reinforced with lignocellulose from Cannabis indica with different fiber loadings 10, 20, 30, 40, and 50% by weight, was obtained. The mechanical properties of randomly oriented intimately mixed fiber particle reinforced composites were determined. Effects of fiber loadings on mechanical properties such as tensile, compressive, flexural strength, and wear resistance were evaluated. Results showed that mechanical properties of URF resin matrix increased considerably when reinforced with particles of Cannabis indica fiber. Thermal (TGA/DTA/DTG and morphological studies (SEM of the resin, fiber and polymer composite thus synthesized were carried out.

  11. Synthesis and characterization of hydrogen-bond acidic functionalized graphene

    Yang, Liu; Han, Qiang; Pan, Yong; Cao, Shuya; Ding, Mingyu

    2014-05-01

    Hexafluoroisopropanol phenyl group functionalized materials have great potential in the application of gas-sensitive materials for nerve agent detection, due to the formation of strong hydrogen-bonding interactions between the group and the analytes. In this paper, take full advantage of ultra-large specific surface area and plenty of carbon-carbon double bonds and hexafluoroisopropanol phenyl functionalized graphene was synthesized through in situ diazonium reaction between -C=C- and p-hexafluoroisopropanol aniline. The identity of the as-synthesis material was confirmed by transmission electron microscopy, Raman spectroscopy, ultraviolet visible spectroscopy, X-ray photoelectron spectroscopy and thermo gravimetric analysis. The synthesis method is simply which retained the excellent physical properties of original graphene. In addition, the novel material can be assigned as an potential candidate for gas sensitive materials towards organophosphorus nerve agent detection.

  12. Characterization of Nanocarbon Copper Composites Manufactured in Metallurgical Synthesis Process

    Knych, Tadeusz; Kwaśniewski, Paweł; Kiesiewicz, Grzegorz; Mamala, Andrzej; Kawecki, Artur; Smyrak, Beata

    2014-08-01

    Currently, there is a worldwide search for new forms of materials with properties that are significantly improved in comparison to materials currently in use. One promising research direction lies in the synthesis of metals containing modern carbon materials ( e.g., graphene, nanotubes). In this article, the research results of metallurgical synthesis of a mixture of copper and two different kinds of carbon (activated carbon and multiwall carbon nanotubes) are shown. Samples of copper-carbon nanocomposite were synthesized by simultaneously exposing molten copper to an electrical current while vigorously stirring and adding carbon while under an inert gas atmosphere. The article contains research results of density, hardness, electrical conductivity, structure (TEM), and carbon decomposition (SIMS method) for the obtained materials.

  13. Reactivity to Daily Stressors in Adulthood: The Importance of Stressor Type in Characterizing Risk Factors

    Hay, Elizabeth L.; Diehl, Manfred

    2010-01-01

    This study examined daily stressors in adults aged 18 to 89 years (M = 49.6 years) over 30 days. We examined the role of individual factors (i.e., age, self-concept differentiation, perceived control) in physical and psychological reactivity to interpersonal, network, home, and health stressors. Findings were consistent with the perspective that adults were less reactive to stress on days they felt in control and that younger adults and adults with high self-concept differentiation (SCD) were...

  14. Synthesis and characterization of mesoporous Si–MCM-41 ...

    Administrator

    Table S1. MCM-41 synthesis strategies—parameters optimized. BET surface area at different temperature (m2/g). SiO2. Template Template H2O Temp. Aging. Parameters. No. source source mole mole. (°C) time (h) pH. 550 °C. 700 °C. 900 °C. Aging time. 1. Na2SiO3. CTABr. 0⋅25. 80. RT. 1. 10⋅5. 640. 490. 370. 2.

  15. Synthesis, Characterization and Applications in Catalysis of Polyoxometalate/Zeolite Composites

    Frédéric Lefebvre

    2016-05-01

    Full Text Available An overview of the synthesis, characterization and catalytic applications of polyoxometalates/zeolites composites is given. The solids obtained by direct synthesis of the polyoxometalate in the presence of the zeolite are first described with their applications in catalysis. Those obtained by a direct mixing of the two components are then reviewed. In all cases, special care is taken in the localization of the polyoxometalate, inside the zeolite crystal, in mesopores or at the external surface of the crystals, as deduced from the characterization methods.

  16. Synthesis and Characterization of Two New p-tert-Butylcalix[4]-arene Schiff Bases

    Saeed Taghvaee Ganjali

    2001-03-01

    Full Text Available Synthesis and characterization of two new Schiff bases of p-tertbuthylcalix[4]arene (H2L1 and HL2 is described. The synthesis of H2L1 and HL2 has been achieved by the condensation of salicylaldehyde with the amine group of upper rim monoamine p-tert-butylcalix[4]arene in ethanol. These compounds have been characterized on the basis of elemental analysis and spectral data. Solvatochromicity and fluorescence properties were observed and measured for H2L1 and HL2. Solvatochromicity of these ligands indicates their potential for NLO applications.

  17. [Synthesis and Characterization of a Sugar Based Electrolyte for Thin-film Polymer Batteries

    1998-01-01

    The work performed during the current renewal period, March 1,1998 focused primarily on the synthesis and characterization of a sugar based electrolyte for thin-film polymer batteries. The initial phase of the project involved developing a suitable sugar to use as the monomer in the polymeric electrolyte synthesis. The monomer has been synthesized and characterized completely. Overall the yield of this material is high and it can be produced in relatively large quantity easily and in high purity. The scheme used for the preparation of the monomer is outlined along with pertinent yields.

  18. Synthesis, spectroscopic studies and reactivity of triphenylphosphine ruthenium (II) complexes with N-heterocyclic ligands

    Rivera, A.B.

    1989-01-01

    Reported is the chemistry of triphenylphosphine ruthenium (II) complexes of general formula RuCl 2 (PPh 3 ) 2 L 2 and RuCl 2 (PPh 3 ) 2 A, obtained from the reaction of RuCl 2 (PPh 3 ) 3 with N-heterocyclic ligands L, or A (of ambidentate nature). The electronic spectra exhibit two strong metal-to-ligand charge-transfer bands, ascribed to the b 1 (dxz)->b 1 (pi) and a 2 (dxy)->a 2 (pi) transitions, and a third, weak band ascribed to the b 2 (dyz)->a 2 (pi) transition. The electronic states and the vibrational modes of the complexes were characterized by means of their resonance Raman and infrared absorption spectra. Thermogravimetric and thermodifferential analysis indicated that the melting process is succeeded by an exothermic reaction, and that the weigh loss starts to occur only after this step. The complexes dissociated in CHCl 3 solution, showing preferential labilization of the phosphine ligands, as in the case of the hydrogenation catalyst Ru(PPh 3 ) 3 Cl 2 . In the presence of CO, RuCl 2 (CO) 2 L 2 complexes were gennerated. Several derivatives were isolated and characterized. (author) [pt

  19. Controlling Magnetic and Ferroelectric Order Through Geometry: Synthesis, Ab Initio Theory, Characterization of New Multi-Ferric Fluoride Materials

    Halasyamani, Shiv [Univ. of Houston, TX (United States); Fennie, Craig [Cornell Univ., Ithaca, NY (United States)

    2016-11-03

    We have focused on the synthesis, characterization, and ab initio theory on multi-functional mixed-metal fluorides. With funding from the DOE, we have successfully synthesized and characterized a variety of mixed metal fluoride materials.

  20. Synthesis, structural studies and reactivity of vanadium complexes with tridentate (OSO) ligand.

    Janas, Zofia; Wiśniewska, Dorota; Jerzykiewicz, Lucjan B; Sobota, Piotr; Drabent, Krzysztof; Szczegot, Krzysztof

    2007-05-28

    The direct reaction between [VCl(3)(thf)3] or [VO(OEt)3] and 2,2'-thiobis{4-(1,1,3,3-tetramethyl-butyl)phenol (tbopH(2)) leads to the formation of [V(2)(micro-tbop-kappa(3)O,S,O)2Cl(2)(CH(3)CN)(2)] (1).4CH(3)CN or [V(2)(micro-OEt)2(O)2(tbop-kappa(3)O,S,O)2] (2), respectively, in high yield. Compounds 1 and 2 were characterized by chemical and physical techniques including X-ray crystallography and variable temperature magnetic susceptibility studies (J = -29.1 cm(-1)) for 1. Complexes 1 and 2 were supported on MgCl2 and when activated with aluminium alkyls, were found to effectively polymerize ethene to produce polyethylene with a narrow molecular weight distribution M(w)/M(n) approximately 3.

  1. Synthesis and characterization of zeolite from coal fly ash

    Liu, Yong; Luo, Qiong; Wang, Guodong; Li, Xianlong; Na, Ping

    2018-05-01

    Fly ash (FA) from coal-based thermal power plant was used to synthesize zeolite in NaOH solution with hydrothermal method in this work. Firstly, the effects of calcination and acid treatment on the removal of impurities in fly ash were studied. Then based on the pretreated FA, the effects of alkali concentration, reaction temperature and Si/Al ratio on the synthesis of zeolite were studied in detail. The mineralogy, morphology, thermal behavior, infrared spectrum and specific surface for the synthetic sample were investigated. The results indicated that calcination at 750 °C for 1.5 h can basically remove unburned carbon from FA, and 4 M hydrochloric acid treatment of calcined FA at 90 °C for 2 h will reduce the quality of about 34.3%wt, which are mainly iron, calcium and sulfur elements. The concentration of NaOH, reaction temperature and Si/Al ratio have important effect on the synthesis of zeolite. In this study, 0.5 M NaOH cannot obtain any zeolite. High temperature is beneficial to zeolite synthesis from FA, but easily lead to a variety of zeolites. The synthetic sample contains three kinds of zeolites such as zeolite P, sodalite and zeolite X, when the reaction conditions are 2 M NaOH and 120 °C for 24 h. In this research, quartz always exists in the synthetic sample, but will reduce with the increase of temperature. The synthetic zeolite has the specific surface area of about 42 m2 g‑1 and better thermal stability.

  2. Synthesis and electrochemical characterization of stabilized nickel nanoparticles

    Dominguez-Crespo, M.A.; Ramirez-Meneses, E.; Torres Huerta, A.M. [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, CICATA-IPN Unidad Altamira, Carretera Tampico-Puerto Industrial, C.P. 89600 Altamira, Tamaulipas (Mexico); Montiel-Palma, V. [Centro de Investigaciones Quimicas, Universidad Autonoma del Estado de Morelos, Av. Universidad 1001, Colonia Chamilpa, C.P.62201 Cuernavaca, Morelos (Mexico); Dorantes Rosales, H. [Departamento de Metalurgia, Escuela Superior de Ingenieria Quimica e Industrias Extractivas - IPN, C.P. 07300, D.F. (Mexico)

    2009-02-15

    Nickel stabilized nanoparticles produced by an organometallic approach (Chaudret's method) starting from the complex Ni(1,5-COD){sub 2} were used as electrode materials for hydrogen evolution in NaOH at two temperatures (298 and 323 K). The synthesis of the nickel nanoparticles was performed in the presence of two different stabilizers, 1,3-diaminopropane (DAP) and anthranilic acid (AA), by varying the molar ratios (1:1, 1:2 and 1:5 metal:ligand) in order to evaluate their influence on the shape, dispersion, size and electrocatalytic activity of the metallic particles. The presence of an appropriate amount of stabilizer is an effective alternative to the synthesis of small monodispersed metal nanoparticles with diameters around 5 and 8 nm for DAP and AA, respectively. The results are discussed in terms of morphology and the surface state of the nanoparticles. The importance of developing a well-controlled synthetic method which results in higher performances of the resulting nanoparticles is highlighted. Herein we found that the performance with respect to the HER of the Ni electrodes dispersed on a carbon black Vulcan substrate is active and comparable to that reported in the literature for the state-of-the-art electrocatalysts. Appreciable cathodic current densities of {proportional_to}240 mA cm{sup -2} were measured with highly dispersed nickel particles (Ni-5{sub DAP}). This work demonstrates that the aforementioned method can be extended to the preparation of highly active stabilized metal particles without inhibiting the electron transfer for the HER reaction, and it could also be applied to the synthesis of bimetallic nanoparticles. (author)

  3. Synthesis and characterization of different morphological SnS nanomaterials

    Chaki, Sunil H; Chaudhary, Mahesh D; Deshpande, M P

    2014-01-01

    SnS in three nano forms possessing different morphologies such as particles, whiskers and ribbons were synthesised by chemical route. The morphology variation was brought about in the chemical route synthesis by varying a synthesis parameter such as temperature and influencing the synthesis by use of surfactant. The elemental composition determination by energy dispersive analysis of x-rays (EDAX) showed that all three synthesized SnS nanomaterials were tin deficient. The x-ray diffraction (XRD) study of the three SnS nanomaterials showed that all of them possess orthorhombic structure. The Raman spectra of the three SnS nanomaterials showed that all three samples possess three common distinguishable peaks. In them two peaks lying at 98 ± 1 cm −1 and 224 ± 4 cm −1 are the characteristic A g mode of SnS. The third peak lying at 302 ± 1 cm −1 is associated with secondary Sn 2 S 3 phase. The transmission electron microscopy (TEM) confirmed the respective morphologies. The optical analysis showed that they possess direct as well as indirect optical bandgap. The electrical transport properties study on the pellets prepared from the different nanomaterials of SnS showed them to be semiconducting and p-type in nature. The current–voltage (I–V) plots of the silver (Ag)/SnS nanomaterials pellets for dark and incandescent illumination showed that all configurations showed good ohmic behaviour except Ag/SnS nanoribbons pellet configuration under illumination. All the obtained results are discussed in detail. (paper)

  4. Steric modulation of coordination number and reactivity in the synthesis of lanthanoid(III) formamidinates.

    Cole, Marcus L; Deacon, Glen B; Forsyth, Craig M; Junk, Peter C; Konstas, Kristina; Wang, Jun

    2007-01-01

    Reactions of a range of the readily prepared and sterically tunable N,N'-bis(aryl)formamidines with lanthanoid metals and bis(pentafluorophenyl)mercury (Hg(C6F5)2) in THF have given an extensive series of tris(formamidinato)lanthanoid(III) complexes, [Ln(Form)3(thf)n], namely [La(o-TolForm)3(thf)2], [Er(o-TolForm)3(thf)], [La(XylForm)3(thf)], [Sm(XylForm)3], [Ln(MesForm)3] (Ln=La, Nd, Sm and Yb), [Ln(EtForm)3] (Ln=La, Nd, Sm, Ho and Yb), and [Ln(o-PhPhForm)3] (Ln=La, Nd, Sm and Er). [For an explanation of the N,N'-bis(aryl)formamidinate abbreviations used see Scheme 1.] Analogous attempts to prepare [Yb(o-TolForm)3] by this method invariably yielded [{Yb(o-TolForm)2(mu-OH)(thf)}2], but [Yb(o-TolForm)3] was isolated from a metathesis synthesis. X-ray crystal structures show exclusively N,N'-chelation of the Form ligands and a gradation in coordination number with Ln3+ size and with Form ligand bulk. The largest ligands, MesForm, EtForm and o-PhPhForm give solely homoleptic complexes, the first two being six-coordinate, the last having an eta1-pi-Ar--Ln interaction. Reaction of lanthanoid elements and Hg(C6F5)2 with the still bulkier DippFormH in THF resulted in C--F activation and formation of [Ln(DippForm)2F(thf)] (Ln=La, Ce, Nd, Sm and Tm) complexes, and o-HC6F4O(CH2)4DippForm in which the formamidine is functionalised by a ring-opened THF that has trapped tetrafluorobenzyne. Analogous reactions between Ln metals, Hg(o-HC6F4)2 and DippFormH yielded [Ln(DippForm)2F(thf)] (Ln=La, Sm and Nd) and 3,4,5-F3C6H2O(CH2)4DippForm. X-ray crystal structures of the heteroleptic fluorides show six-coordinate monomers with two chelating DippForm ligands and cisoid fluoride and THF ligands in a trigonal prismatic array. The organometallic species [Ln(DippForm)2(C[triple chemical bond]CPh)(thf)] (Ln=Nd or Sm) are obtained from reaction of Nd metal, bis(phenylethynyl)mercury (Hg(C[triple chemical bond]CPh)2) and DippFormH, and the oxidation of [Sm(DippForm)2(thf)2] with Hg

  5. Synthesis, characterization and oxidative behaviour of dioxoruthenium(VI) complexes

    Agarwal, D.D.; Rastogi, Rachana

    1995-01-01

    Dioxoruthenium(VI) complexes are found to give low yield of epoxide but good yield of cyclohexanone. The complexes are electro active giving metal centered Ru VI /Ru V couple. Cis-stilbene gives trans epoxide and benzaldehyde. Norbornene gives exo epoxy norbornene. The selectivity for allylic oxidation is high. In the present note the synthesis of dioxoruthenium(VI) complexes and their oxidation behaviour is reported. The dioxoruthenium(VI) complexes have been stoichiometrically found to be good oxidants. (author). 21 refs., 1 tab

  6. Solution combustion synthesis and characterization of nanosized bismuth ferrite

    Sai Kumar, V. Sesha; Rao, K. Venkateswara; Krishnaveni, T.; Kishore Goud, A. Shiva; Reddy, P. Ranjith

    2012-06-01

    The present paper describes a simple method of nanosized BiFeO3 by the solution combustion synthesis using bismuth and iron nitrates as oxidizers and the combination fuel of citric acid and ammonium hydroxide, with fuel to oxidizer ratio (Ψ = 1) one. The X-ray Diffraction results indicated rhombohedral phase (R3m) with JCPDS data card no: 72-2035. The ferroelectric transition of the sample at 8310C was detected by differential thermal analysis. Thermal analysis was done by Thermal gravimetric-Differential thermal analyzer and obtained results were presented in this paper.

  7. Synthesis, characterization, antimicrobial and anticancer studies of new steroidal pyrazolines

    Shamsuzzaman

    2016-01-01

    Full Text Available A convenient synthesis of 2′-(2″,4″-dinitrophenyl-5α-cholestano [5,7-c d] pyrazolines 4–6 from cholest-5-en-7-one 1–3 was performed and structural assignment of the products was confirmed on the basis of IR, 1H NMR, 13C NMR, MS and analytical data. The synthesized compounds were screened for in vitro antimicrobial activity against different strains during which compound 6 showed potent antimicrobial behaviour against Corynebacterium xerosis and Staphylococcus epidermidis. The synthesized compounds were also screened for in vitro anticancer activity against human cancer cell lines during which compound 5 exhibited significant anticancer activity.

  8. Synthesis, Characterization and Thermal Diffusivity of Holmium and Praseodymium Zirconates

    Stopyra M.; Niemiec D.; Moskal G.

    2016-01-01

    A2B2O7 oxides with pyrochlore or defected fluorite structure are among the most promising candidates for insulation layer material in thermal barrier coatings. The present paper presents the procedure of synthesis of holmium zirconate Ho2Zr2O7 and praseodymium zirconate Pr2Zr2O7 via Polymerized-Complex Method (PCM). Thermal analysis of precursor revealed that after calcination at relatively low temperature (700°C) fine-crystalline, single-phase material is obtained. Thermal diffusivity was me...

  9. Green synthesis and characterization of silver nanoparticle using Aloe barbadensis

    Thappily, Praveen, E-mail: pravvmon@gmail.com, E-mail: shiiuvenus@gmail.com; Shiju, K., E-mail: pravvmon@gmail.com, E-mail: shiiuvenus@gmail.com [Laboratory for Molecular Photonics and Electronics (LAMP), Department of Physics, National Institute of Technology, Calicut, Kerala 673601 (India)

    2014-10-15

    Green synthesis of silver nanoparticles was achieved by simple visible light irradiation using aloe barbadensis leaf extract as reducing agent. UV-Vis spectroscopic analysis was used for confirmation of the successful formation of nanoparticles. Investigated the effect of light irradiation time on the light absorption of the nanoparticles. It is observed that upto 25 minutes of light irradiation, the absorption is linearly increasing with time and after that it becomes saturated. Finally, theoretically fitted the time-absorption graph and modeled a relation between them with the help of simulation software.

  10. Green synthesis and characterization of silver nanoparticle using Aloe barbadensis

    Thappily, Praveen; Shiju, K.

    2014-01-01

    Green synthesis of silver nanoparticles was achieved by simple visible light irradiation using aloe barbadensis leaf extract as reducing agent. UV-Vis spectroscopic analysis was used for confirmation of the successful formation of nanoparticles. Investigated the effect of light irradiation time on the light absorption of the nanoparticles. It is observed that upto 25 minutes of light irradiation, the absorption is linearly increasing with time and after that it becomes saturated. Finally, theoretically fitted the time-absorption graph and modeled a relation between them with the help of simulation software

  11. Synthesis, characterization, and subcellular localization studies of amino acid-substituted porphyrinic pigments

    van Diggelen, Lisa; Khin, Hnin; Conner, Kip; Shao, Jenny; Sweezy, Margaretta; Jung, Anna H.; Isaac, Meden; Simonis, Ursula

    2009-06-01

    Stopping cancer in its path occurs when photosensitizers (PSs) induce apoptotic cell death after their exposure to light and the subsequent formation of reactive oxygen species. In pursuit of our hypothesis that mitochondrial localizing PSs will enhance the efficacy of the photosensitizing process in photodynamic therapy, since they provoke cell death by inducing apoptosis, we synthesized and characterized tetraphenylporphyrins (TPPs) that are substituted at the paraphenyl positions by two amino acids and two fluoro or hydroxyl groups, respectively. They were prepared according to the Lindsey-modified Adler-Longo methodology using trifluoromethanesulfonylchloride (CF3SO2Cl) as a catalyst instead of trifluoroacetic acid. The use of CF3SO2Cl yielded cleaner products in significantly higher yields. During the synthesis, not only the yields and work-up procedure of the TPPs were improved by using CF3SO2Cl as a catalyst, but also a better means of synthesizing the precursor dipyrromethanes was tested by using indium(III) chloride. Column chromatography, HPLC, and NMR spectroscopy were used to separate and characterize the di-amino acid-dihydroxy, or difluoro-substituted porphyrins and to ascertain their purity before subcellular localization studies were carried out. Studies using androgen-sensitive human prostate adenocarcinoma cells LNCaP revealed that certain amino acid substituted porphyrins that are positively charged in the slightly acidic medium of cancer cells are very useful in shedding light on the targets of TPPs in subcellular organelles of cancer cells. Although some of these compounds have properties of promising photosensitizers by revealing increased water solubility, acidic properties, and innate ability to provoke cell death by apoptosis, the cell killing efficacy of these TPPs is low. This correlates with their subcellular localization. The di-amino acid, di-hydroxy substituted TPPs localize mainly to the lysosomes, whereas the di

  12. Synthesis and characterization of lanthanide-based luminescent nanoparticles: toward new bio-labels

    Lechevallier, Severine

    2010-01-01

    This work deals with the development of luminescent nanoparticles (NPs) suitable as bio-labels. Inorganic NPs have been synthesized, in which luminescent ion (Eu 3+ in most of cases) is substituting ions of the oxide host matrix. NPs of Ln(OH)CO 3 :Eu 3+ (Ln = Y or Gd), Ln 2 O 3 :Eu 3+ , Ln 2 O 2 S:Eu 3+ and SiO 2 :Eu 3+ have been characterized by the way of TGA, WAXS-XRD, TEM, IR and photoluminescence (PL) techniques. The controlled precipitation using urea as precipitating agent is the way chosen and optimized to obtain spherical and monodispersed in size (150±15 nm) NPs. These particles of amorphous lanthanide hydroxycarbonate can directly be used as luminescent bio-labels or after their conversion in oxide or oxi-sulfide. For the silica particles, the synthesis by aerosol pyrolysis has been used. The obtained particles are spherical with a main diameter of 350 nm. In a second step, the surface of the inorganic NPs has been modified, in order to graft amino-reactive functions. Several modification ways have been explored: with APTES (aminopropyltriethoxysilane), with TEOS (tetra-ethoxysilane) and then APTES, or with a TEOS/APTES mixture. The same characterizations techniques have been applied to the modified particles, and chemical analysis, solid state NMR and XPS. DLS and ζ-potential of the NPs dispersed in water have also been measured. These analyses have been completed by the evaluation of the number of accessible amine functions by coupling with FITC (fluorescein isothiocyanate). The direct modification of oxides (Y 2 O 3 or Gd 2 O 3 ) with APTES is the best way, and an homogenous layer of 1 nm with a high number of accessible amine can be graft. Finally, to move toward luminescent bio-labelling in biological medium, the luminescence of the NPs has been observed and analyzed using: - A spectro-fluorimeter, after their dispersion in water; - A fluorescence microscope, on glass slides, under broad band excitation; - A confocal microscope, under laser

  13. Chemical Characterization and Reactivity Testing of Fuel-Oxidizer Reaction Product (Test Report)

    1996-01-01

    The product of incomplete reaction of monomethylhydrazine (MMH) and nitrogen tetroxide (NTO) propellants, or fuel-oxidizer reaction product (FORP), has been hypothesized as a contributory cause of an anomaly which occurred in the chamber pressure (PC) transducer tube on the Reaction Control Subsystem (RCS) aft thruster 467 on flight STS-51. A small hole was found in the titanium-alloy PC tube at the first bend below the pressure transducer. It was surmised that the hole may have been caused by heat and pressure resulting from ignition of FORP. The NASA Johnson Space Center (JSC) White Sands Test Facility (WSTF) was requested to define the chemical characteristics of FORP, characterize its reactivity, and simulate the events in a controlled environment which may have lead to the Pc-tube failure. Samples of FORP were obtained from the gas-phase reaction of MMH with NTO under laboratory conditions, the pulsed firings of RCS thrusters with modified PC tubes using varied oxidizer or fuel lead times, and the nominal RCS thruster firings at WSTF and Kaiser-Marquardt. Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), accelerating rate calorimetry (ARC), ion chromatography (IC), inductively coupled plasma (ICP) spectrometry, thermogravimetric analysis (TGA) coupled to FTIR (TGA/FTIR), and mechanical impact testing were used to qualitatively and quantitatively characterize the chemical, thermal, and ignition properties of FORP. These studies showed that the composition of FORP is variable but falls within a limited range of compositions that depends on the fuel loxidizer ratio at the time of formation, composition of the post-formation atmosphere (reducing or oxidizing), and reaction or postreaction temperature. A typical composition contains methylhydrazinium nitrate (MMHN), ammonium nitrate (AN), methylammonium nitrate (MAN), and trace amounts of hydrazinium nitrate and 1,1-dimethylhydrazinium nitrate. The thermal decomposition

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

    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. Non-nitric oxide based metallovasodilators: synthesis, reactivity and biological studies.

    Sá, Denise S; Fernandes, André F; Silva, Carlos D S; Costa, Paula P C; Fonteles, Manassés C; Nascimento, Nilberto R F; Lopes, Luiz G F; Sousa, Eduardo H S

    2015-08-14

    There is an increasing number of compounds developed to target one or more pathways involved in vasodilation. Some studies conducted with azaindole and indazole derivatives showed cardiovascular activity associated with these compounds. Fast and easy structural modification of these organic molecules can be achieved using metal complexes promoting a much larger spatial change than organic strategies, potentially leading to novel drugs. Here, we have prepared a series of complexes with a formula cis-[RuCl(L)(bpy)(2)]PF(6), where L = 7-azaindole (ain), 5-azaindole (5-ain), 4-azaindole (4-ain), indazole (indz), benzimidazole (bzim) or quinoline (qui), which were characterized by spectroscopic and electrochemical techniques (CV, DPV). These compounds showed reasonable stability exhibiting photoreactivity only at low wavelength along with superoxide scavenger activity. Cytotoxicity assays indicated their low activity preliminarily supporting in vivo application. Interestingly, vasodilation assays conducted in rat aorta exhibited great activity that largely improved compared to free ligands and even better than the well-studied organic compound (BAY 41-42272), with IC(50) reaching 55 nM. These results have validated this strategy opening new opportunities to further develop cardiovascular agents based on metallo-bicyclic rings.

  16. Synthesis, reactivity, and properties of N-fused porphyrin rhenium(I) tricarbonyl complexes.

    Toganoh, Motoki; Ikeda, Shinya; Furuta, Hiroyuki

    2007-11-12

    The thermal reactions of N-fused tetraarylporphyrins or N-confused tetraarylporphyrins with Re2(CO)10 gave the rhenium(I) tricarbonyl complexes bearing N-fused porphyrinato ligands (4) in moderate to good yields. The rhenium complexes 4 are characterized by mass, IR, 1H, and 13C NMR spectroscopy, and the structures of tetraphenylporphynato complex 4a and its nitro derivative 15 are determined by X-ray single crystal analysis. The rhenium complexes 4 show excellent stability against heat, light, acids, bases, and oxidants. The aromatic substitution reactions of 4 proceed without a loss of the center metal to give the nitro (15), formyl (16), benzoyl (17), and cyano derivatives (19), regioselectively. In the electrochemical measurements for 4, one reversible oxidation wave and two reversible reduction waves are observed. Their redox potentials imply narrow HOMO-LUMO band gaps of 4 and are consistent with their electronic absorption spectra, in which the absorption edges exceed 1000 nm. Theoretical study reveals that the HOMO and LUMO of the rhenium complexes are exclusively composed of the N-fused porphyrin skeleton. Protonation of 4 takes place at the 21-position regioselectively, reflecting the high coefficient of the C21 atom in the HOMO orbital. The skeletal rearrangement reaction from N-confused porphyrin Re(I) complex (8) to N-fused porphyrin Re(I) complex (4) is suggested from the mechanistic study as well as DFT calculations.

  17. Combustion synthesis and characterization of uranium and thorium tellurides

    Czechowicz, D.G.

    1985-10-01

    This report describes an investigation of the chemical systems uranium-tellurium and thorium-tellurium. A novel synthesis technique, combustion synthesis, which uses the exothermic heat of reaction rather than externally supplied heat, was utilized to form the phases UTe, U 3 Te 4 , and UTe 2 in the U-Te system and the phases ThTe, Th 2 Te 3 , and ThTe 2 in the Th-Te system from reactions of the type U/sub x/ + Te/sub y/ = U/sub x/Te/sub y/. With this synthetic method, U-Te and Th-Te products could be formed in a matter of seconds, and the purity of the products was often greater than that of the starting materials used. Control over final product stoichiometry was found to be very difficult. The product phase distribution observed in combustion products, as determined by x-ray diffraction, electron microprobe, and optical metallographic methods, was found to be spatially complex. Lattice constants were calculated from x-ray diffraction patterns for the compounds UTe, U 3 Te 4 , and ThTe. SOLGASMIX thermodynamic equilibrium calculations were performed using available and estimated thermodynamic data on the system U-Te-O in an attempt to understand the products formed by combustion. Adiabatic combustion reaction temperatures for specific U-Te and Th-Te reactions were also calculated utilizing available and estimated thermodynamic data. 71 refs., 31 figs., 15 tabs

  18. MCM-41 ordered mesoporous molecular sieves synthesis and characterization

    Rogério A.A. Melo

    1999-07-01

    Full Text Available The aim of this work was to study the hydrothermal synthesis of Si and SiAlMCM-41 performed under both autogenic pressure and refluxing conditions. XRD data showed that the MCM-41 phase may be formed by both processes and that the synthesized material in the presence of Al and/or under reflux presents the hexagonally arrangement of less ordered mesopores. However, as verified by XRD and physisorption data, the order was improved with higher synthesis times. 29Si and 1H - 29Si C/P MAS NMR spectra showed that a great part of the Si atoms exists as silanol groups which originate resonance peaks at -110, -100 and -91 ppm. The presence of Al atoms may generate Si(3Si, Al and Si(2Si, 2Al environments which might be contributing to resonance peaks at -100 and -91 ppm. The 27Al MAS NMR spectrum of the as synthesized AlSiMCM-41 showed a resonance peak of tetrahedral framework aluminum close to 53 ppm and two others, one close to 14 ppm attributed to Al(H2O6+3 species and the other a weak signal close to 32 ppm attributed to pentacoordinated Al. 27Al MAS NMR spectra of the calcined sample showed a peak at 0 ppm corresponding to an hexacoordinated extra-framework aluminum formed during calcination.

  19. Synthesis and characterization of hydroxyapatite from fish bone waste

    Marliana, Ana, E-mail: na-cwith22@yahoo.co.id; Fitriani, Eka; Ramadhan, Fauzan; Suhandono, Steven; Yuliani, Keti; Windarti, Tri [Chemistry Department, Faculty of Science and Mathematics, Diponegoro University, Indonesia, 50 275 (Indonesia)

    2015-12-29

    Waste fish bones is a problem stemming from activities in the field of fisheries and it has not been used optimally. Fish bones contain calcium as natural source that used to synthesize hydroxyapatite (HA). In this research, HA synthesized from waste fish bones as local wisdom in Semarang. The goal are to produce HA with cheaper production costs and to reduce the environmental problems caused by waste bones. The novelty of this study was using of local fish bone as a source of calcium and simple method of synthesis. Synthesis process of HA can be done through a maceration process with firing temperatures of 1000°C or followed by a sol-gel method with firing at 550°C. The results are analyzed using FTIR (Fourier Transform Infrared), XRD (X-Ray Diffraction) and SEM-EDX (Scanning Electron Microscopy-Energy Dispersive X-Ray). FTIR spectra showed absorption of phosphate and OH group belonging to HA as evidenced by the results of XRD. The average grain size by maceration and synthesized results are not significant different, which is about 69 nm. The ratio of Ca/P of HA by maceration result is 0.89, then increase after continued in the sol-gel process to 1.41. Morphology of HA by maceration results are regular and uniform particle growth, while the morphology of HA after the sol-gel process are irregular and agglomerated.

  20. Synthesis and properties of bis(pentamethylcyclopentadienyl) actinide hydrocarbyls and hydrides. A new class of highly reactive f-element organometallic compounds

    Fagan, P.J.; Manriquez, J.M.; Maatta, E.A.; Seyam, A.M.; Marks, T.J.

    1981-01-01

    The synthesis and chemical and physcochemical properties of Th and U bis(pentamethylcyclopentadienyl) chlorides, hydrocarbyls, chlorohydrocarbyls, and hydrides are reported. The reaction of the precursor compounds M[eta 5 -(CH 3 ) 5 C 5 ] 2 Cl 2 with 2 equiv of lithium reagent RLi produces M[eta 5 -(CH 3 ) 5 ] 2 R 2 compounds where R = CH 3 , CH 2 Si(CH 3 ) 3 , CH 2 C(CH 3 ) 3 , CH 2 C 6 H 5 , and C 6 H 5 (M = Th) and R = CH 3 , CH 2 Si(CH 3 ) 3 , CH 2 C 6 H 5 , and C 6 H 5 (M = U) in good yield. With 1 equiv of lithium reagent, M[eta 5 -(CH 3 ) 5 C 5 ] 2 (R)Cl compounds where R = CH 2 C(CH 3 ) 3 , CH 2 Si(CH 3 ) 3 , CH 2 C 6 H 5 , and C 6 H 5 (M = Th) and R = CH 2 C(CH 3 ) 3 CH 2 Si(C 3 ) 3 , CH 2 C 6 H 5 , and C 6 H 5 , and C 6 H 5 (M = U) are formed in high yield. The M[eta 5 -(CH 3 ) 5 C 52 (C 3 )Cl compounds can be synthesized by redistribution between the corresponding dimethyl and dichloro complexes. The new organoactinides were thoroughly characterized by elemental analysis, 1 H NMR and vibrational spectroscopy, and in many cases cryoscopic molecular weight measurements. The hydrocarbyls and chlorohydrocarbyls generally exhibit high thermal stability. However, the diphenyl compounds react readily with C 6 D 6 to yield, via a benzyne complex, the corresponding M(C 6 D 5 ) 2 compounds. The Th bis(neopentyl) complex reacts with benzene to produce the corresponding diphenyl complex. Competition experiments at -78 0 C indicate that the Th complexes are more reactive than those of U. The M[eta 5 -(CH 3 ) 5

  1. Nano-/micro metallic wire synthesis on Si substrate and their characterization

    Kaur, Jaskiran; Kaur, Harmanmeet; Singh, Surinder; Kanjilal, Dinakar; Chakarvarti, Shiv Kumar

    2014-01-01

    Nano-/micro wires of copper are grown on semiconducting Si substrate using the template method. It involves the irradiation of 8 um thick polymeric layer coated on Si with150 MeV Ni ion beam at a fluence of 2E8. Later, by using the simple technique of electrodeposition, copper nano-/micro wires were grown via template synthesis. Synthesized wires were morphologically characterized using SEM and electrical characterization was carried out by finding I-V plot

  2. Synthesis, characterization and magnetic properties of polyaniline/ γ ...

    Administrator

    are characterized by using scanning electron microscopy (SEM), X-ray diffraction (XRD) and infrared (IR) spectroscopy. .... cathode ray oscilloscope (CRO) using high-field hysteresis loop tracer and different .... and in-depth understanding.

  3. Synthesis, characterization and antimicrobial studies of Cu(II) and ...

    chloroaniline were synthesized and characterized by solubility test, infrared spectra, conductivity measurement, magnetic susceptibility, metal-ligand ratio determination, and antimicrobial activity. The low molar conductance values range (16.

  4. Synthesis, characterization and antimicrobial studies of bio silica ...

    2018-05-16

    May 16, 2018 ... Cynodon dactylon; green approach; silica nanoparticles; characterization; antimicrobial studies. 1. .... The obtained powder was well-ground with a mortar and ..... Inhalation of SiCl4 fumes irritates nose, throat and lungs.

  5. Synthesis and characterization of metal ion-imprinted polymers

    2018-03-29

    Mar 29, 2018 ... polymers (CPs) were synthesized through the same method without using metal ion. Characterization of the ... tizanidine obtained from MMIP-NPs showed that signifi- .... C=C vari- able alkene stretching band at 1636 cm. −1.

  6. Synthesis, characterization, x-ray structure and antimicrobial activity ...

    Methods: Pyridine-based thiosemicarbazide was synthesized, characterized and evaluated for antimicrobial activity. ... homogeneity of the compounds was checked by. TLC performed ..... properties of novel N-methyl-1,3,4-thiadiazol-2- amine.

  7. Synthesis and characterization of Eichhornia-mediated copper oxide ...

    In this paper, we report the biosynthesis and characterization of copper oxide nanoparticles ... copper oxide nanoparticles by simple, cost-effective and ecofriendly method as an alternative to other available ... Currently, zinc oxide, gold, silver.

  8. Synthesis, Structure, and Reactivity ofbis(1,2,4-tri-t-butylcyclopentadienyl) Complexes of Cerium

    Werkema, Evan L. [Univ. of California, Berkeley, CA (United States)

    2005-05-19

    fluorobenzenes, permittingthe synthesis of specific Cp'2CeC6HxF5-x complexes. The crystal structureof Cp'2CeC6F5 is presented. The hydride and the metallacycle react withfluoromethanes, CH4-xFx, x = 1-3, through postulated Cp'2CeCH3-xFx intermediates to generate Cp'2CeF and other products. The other products,CH4, tri-t-butylbenzenes, tri-t-butylfluorobenzenes, and a presumedmetallocene cerium fluoride with one Cp' and one (Me2EtC)(Me3C)2C5H2 ligand, suggest a decomposition pathway for Cp'2CeCH3-xFx , x = 1-3, thatinvolves carbenes or carbenoids, which are trapped. The hydridepolymerizes ethylene, but hydrogenates other olefins. The metallacycleactivates C-H bonds in olefins and aromatics to generate new complexeswith Ce-C bonds. The hydride reacts with one equivalent of CO in pentaneto generate (Cp'2Ce)2CH2O, whose crystal structure shows the presence ofa bridging dianionic formaldehyde ligand. (Cp'2Ce)2CH2O reacts H2 to givethe hydride and Cp'2CeOMe, or with a mixture of H2 and CO to generate Cp'2CeOMe exclusively. (Cp'2Ce)2CH2O or the hydride can react with anadditional equivalent of CO to generate dimeric enediolate,(Cp'2CeCHO)2.

  9. Synthesis and characterization of poly(glycerol citrate/sebacate)

    Brioude, Michel M.; Guimaraes, Danilo H.; Fiuza, Raigenis P.; Boaventura, Jaime S.; Jose, Nadia M.

    2011-01-01

    In this work were prepared and characterized the poly(glycerol citrate/sebacate) in three different ratios between acids. The polymers were prepared by a polycondensation reaction between glycerol and citric/sebacic acids and characterized by X-ray diffraction (XRD), infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), scanning differential calorimetry (DSC), scanning electron microscopy (SEM). The results showed that the polymers are polyesters and its crystallinity, thermal and morphological properties were modified by sebacic acid adding. (author)

  10. Extended germa[N]pericyclynes: synthesis and characterization.

    Tanimoto, Hiroki; Fujiwara, Taro; Mori, Junta; Nagao, Tomohiko; Nishiyama, Yasuhiro; Morimoto, Tsumoru; Ito, Shunichiro; Tanaka, Kazuo; Chujo, Yoshiki; Kakiuchi, Kiyomi

    2017-02-14

    We herein describe the syntheses and characterization of extended germa[N]pericyclynes, which are macrocycles composed of germanium-butadiyne units. The obtained novel extended germa[4]-[8]pericyclynes were characterized by X-ray crystallography, UV-Vis spectroscopy, fluorescence and phosphorescence emission spectroscopy, and cyclic voltammetry, and exhibited characteristic absorptions and emissions. Density functional theory (DFT) calculations suggested smaller HOMO-LUMO gap energy compared to that of general germapericyclynes.

  11. Synthesis and characterization of tetraphenylporphyrinate of dysprosium route dysprosium acetylacetonate

    Martinez M, V.

    1992-01-01

    Dysprosium bis (tetraphenylporphyrinate) and bis (dysprosium) Tris (tetraphenylporphyrinate) were synthesized from dysprosium tetraphenylporphyrinate prepared in situ, and characterized by IR, UV-vis, TGA, DTA, EPR and magnetic susceptibility measurements. The double decker compound was obtained by direct oxidation of the HDy(TPP) 2 intermediate. The existence of the radical anion, (TPP) - , in the double decker product was conformed by EPR spectrometry. Dysprosium monoporphyrinate was isolated and characterized by the same techniques. (Author)

  12. Synthesis and structural characterization of piperazino-modified DNA that favours hybridization towards DNA over RNA

    Skov, Joan; Bryld, Torsten; Lindegaard, Dorthe

    2011-01-01

    We report the synthesis of two C4'-modified DNA analogues and characterize their structural impact on dsDNA duplexes. The 4'-C-piperazinomethyl modification stabilizes dsDNA by up to 5°C per incorporation. Extension of the modification with a butanoyl-linked pyrene increases the dsDNA stabilizati...

  13. Chemical synthesis, characterization and evaluation of antimicrobial properties of Cu and its oxide nanoparticles

    Motlatle, Abesach M

    2016-10-01

    Full Text Available of Nanoparticle Research, vol. 18: DOI: 10.1007/s11051-016-3614-8 Chemical synthesis, characterization and evaluation of antimicrobial properties of Cu and its oxide nanoparticles Motlatle AM Kesevan Pillai S Scriba MR Ray SS ABSTRACT: Cu...

  14. A facile soft template synthesis and characterization of PbHAsO4 nanocrystals

    Xiu Zhiliang; Lue Mengkai; Zhou Guangjun; Gu Feng; Zhang Haiping; Xu Dong; Yuan Duorong

    2004-01-01

    Monoclinic lead hydrogen arsenate (LHA) nanocrystals with different crystallization morphologies and crystallite sizes were prepared successfully by a soft template synthesis method in the presence of sodium dodecylbenzenesulfonate (SDBS) or polyvinylpyrrolidone (PVP). The products were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The possible mechanism of SDBS and PVP in the experiment was briefly illustrated

  15. Synthesis, characterization and behaviour to gamma radiation of the bis-L-alaninato-copper (II)

    Passos, B.F.T.

    1985-01-01

    The behaviour of coordinated compound obtained from the copper (II) and the L-(+)- alanine to gamma radiation was determined. A study of synthesis and characterization of this complex was made with elementary analysis, ultraviolet and visible electronic spectroscopy, infrared vibrational spectroscopy, proton magnetic resonance spectroscopy and thermo-gravimetric analysis. (C.G.C.)

  16. Synthesis of Zinc Diethyldithiocarbamate (ZDEC) and Structure Characterization using Decoupling 1H NMR

    Sujarit, Jenjira; Phutdhawong, Weerachai

    2003-10-01

    A synthesis of zinc diethyldithiocarbamate (ZDEC) has been studied. The optimization mole ratio of the synthetic process was 2: 2: 2: 1 of diethylamine, carbondisulfide, sodium hydroxide, and zinc chloride. Characterization was carried out mainly by analyzing its spectroscopic properties especially decoupling 1 H NMR technique. ZDEC was obtained in 48.5% yield

  17. Synthesis and characterization of an additive type super plasticizers obtained from plastics cups of polystyrene

    Araujo, Carolina G.L.; Freire, Carolina B.; Tello, Cledola C. de O.

    2013-01-01

    This paper aims to describe the synthesis of an additive type superplasticizer from alternative material - plastic cups used of polystyrene - and characterize it physically and chemically in order to verify their efficiency and compare it with a commercial use superplasticizer. Following the search, the synthesized superplasticizer is used in mortars to assess their efficiency

  18. Synthesis and characterization of iron-cobalt (FeCo) alloy nanoparticles supported on carbon

    Koutsopoulos, Sotiris; Barfod, Rasmus; Eriksen, Kim Michael

    2017-01-01

    of the alloy nanoparticles differed depending on the preparation method. When the wet impregnation technique of acetate precursor salts of Fe and Co were used for the synthesis, the size of FeCo alloy nanoparticles was approximately 13 nm. FeCo alloy nanoparticles were characterized by crystallography (XRD...

  19. Synthesis and characterization of homogeneous interstitial solutions of nitrogen and carbon in iron-based lattices

    Brink, Bastian Klüge

    work in synthesis and characterization of interstitial solutions ofnitrogen and carbon in iron-based lattices. In order to avoid the influences of gradients incomposition and residual stresses, which are typically found in treated surface layers,homogenous samples are needed. These were prepared from...

  20. Synthesis and characterization of N-t-BOC protected pyrrole-sulfur oligomers and polymers

    Groenendaal, L.; Pieterse, K.; Vekemans, J.A.J.M.; Meijer, E.W.

    1997-01-01

    The synthesis and characterization of a new class of pyrrole-sulfur compounds is described. These compounds are designed to be precursors for an organic analogue of poly(sulfur nitride). Poly(N-t-BOC-2.5-pyrrolyl sulfide) was prepared from N-t-BOC-2,5-dibromopyrrole by first lithiating this compound

  1. Design, synthesis, and characterization of novel fine-particle, unsupported catalysts for coal liquefaction

    Klein, M.T.

    1991-12-30

    The purpose of this work is to investigate the kinetics-assisted design, synthesis and characterization of fme-pardcle, unsupported catalysts for coal liquefaction. The goal is to develop a fundamental understanding of coal catalysis and catalysts that will, in turn, allow for the specification of a novel optimal catalyst for coal liquefaction.

  2. Synthesis and characterization of hydroxyapatite crystals: a review study on the analytical methods

    Koutsopoulos, S.

    2002-01-01

    For the synthesis of hydroxyapatite crystals from aqueous solutions three preparation methods were employed. From the experimental processes and the characterization of the crystals it was concluded that aging and precipitation kinetics are critical for the purity of the product and its

  3. Synthesis, characterization and gas sensing performance of SnO2 ...

    Synthesis, characterization and gas sensing performance of SnO2 thin films prepared by spray pyrolysis. GANESH E PATIL, D D KAJALE, D N CHAVAN†, N K PAWAR††, P T AHIRE, S D SHINDE#,. V B GAIKWAD# and G H JAIN. ∗. Materials Research Laboratory, Arts, Commerce and Science College, Nandgaon 423 106, ...

  4. Carbene complexes of zirconium. Synthesis, structure, and reactivity with carbon monoxide to affort coordinated ketene

    Barger, P.T.; Santarsiero, B.D.; Armantrout, J.; Bercaw, J.E.

    1984-01-01

    Treatment of Cp 2 Zr(L)(CO) (Cp = C 5 H 5 ; L = PMe 3 , CO) with Cp* 2 ZrH 2 (Cp* = C 5 Me 5 ) affords zirconium oxycarbene complexes, Cp 2 (L)Zr double bond CHO single bond Zr(X)Cp* 2 (L = PMe 3 , X = H, I; L = CO, X = H), that represent some of the first examples of group 4 metal-to-carbon multiple bonding. The first X-ray diffraction structure determination of a zirconium carbene complex, that of Cp(PMe 3 )Zr double bond CHO single bond Zr(H)Cp* 2 .C 6 H 6 , is reported (C2/c, a = 27.318 (4) A, b = 19.895 (3) A, c = 19.932 (5) A β = 132.188 (10) 0 , Z = 8) and shows a very short Zr-C bond length of 2.117 (7) A. Treatment of Cp 2 (CO)Zr double bond CHO single bond Zr(H)Cp* 2 with CH 3 I or Cp 2 (PMe 3 )Zr double bond CHO single bond Zr(I)Cp* 2 with CO affords the zirconium substituted enediolate zirconacycle, Cp* 2 ZrOCH double bond C(Zr(I)Cp 2 )O, which has been characterized by an X-ray diffraction study (P2 1 /c, a = 15.866 (4) A, b = 10.673 (3) A, c = 20.561 (4) A, β = 105.5 (2) 0 , Z = 4). This complex most likely forms by coupling of the zirconoxycarbene and a carbonyl to give a metal-coordinated ketene intermediate that subsequently rearranges to the isolated product. An isotopic crossover experiment has demonstrated that the new carbon-carbon bond is formed in an intramolecular coupling step. The ketene intermediate can be trapped by dissolving Cp 2 (CO)Zr double bond CHO single bond Zr(H)Cp* 2 in pyridine, giving Cp 2 (py)Zr(O double bond C double bond CHOZr(I)Cp* 2 ). Treatment of the isolated ketene complex with CH 3 I in benzene gives the enediolate zirconocycle; in pyridine Cp 2 (py)Zr(O double bond C double bond CHOZr(I)Cp* 2 ) can be observed spectroscopically. 38 references, 4 figures, 5 tables

  5. Synthesis and characterization of porous microspheres bearing pyrrolidone units

    Maciejewska, M., E-mail: mmacieje@umcs.pl; Kołodyńska, D.

    2015-01-15

    Porous microspheres of glycydyl methacrylate (GMA) cross-linked with trimethylolpropane trimethacrylate (TRIM) were prepared with toluene as porogen by suspension-emulsion polymerization. With increasing molar ratio of the functional monomer to cross-linker, the epoxy group content increases significantly whereas the parameters of porous structure (specific surface area and total pore volume) decreases. In order to obtain adsorbents bearing functional groups the porous methacrylate network was modified by subsequent reaction with pyrrolidone. The materials were studied using elemental analysis, infrared spectroscopy, atomic force microscopy (AFM), attenuated total reflection (ATR) spectroscopy, Raman spectroscopy, thermal gravimetry. Additionally, polymers sorption capacity towards Cu(II) was investigated. - Highlights: • Porous microspheres with reactive epoxy group were synthesized. • Highly developed porous structure was created. • Pyrrolidone units were incorporated during ring–opening reaction. • Polymers sorption capacity towards Cu (II) was investigated.

  6. Characterization of coal and char reactivity as a function of burn-off

    Biede, O.; Swane Lund, J. [DTU, Dept. of Energy Engineering (Denmark); Holst Soerensen, L. [Risoe National Lab. (Denmark); Peck, R.E. [Arizona State University (United States)

    1996-12-01

    Four coal types have been tested under varying burning conditions in three high-temperature experimental facilities: A 1.3 MW test furnace, an entrained flow reactor and a down-fired tube furnace with a flat flame burner have been used to produce char samples. More than one hundred partly burned samples with burn-off from 30% to 99% have been collected from the experimental facilities, and analyzed in a thermogravimetric analyser (TGA) giving, besides the proximate data, a char burning profile of each individual sample, using a linear TGA-temperature ramp of 3 deg. C/minute. The burning profile derived by this procedure agrees well with reactivity profiles derived at a constant temperature. It is shown that small particle burn faster than large particles, and that small particles in general are more reactive than large particles. Particles burn faster when the oxygen partial pressure is increased, and apparently the oxygen partial pressure influences the combustion rate differently for different coal types. Except for one coal type, that apparently behaves differently in different burning environments, the ranking with respect to reactivity among the coals remains consistent at both high and at low temperatures. It is further shown how samples from one coal type varies more in behavior than samples from the other coal types, indicating a larger inhomogeneity of this coal. In general the reactivity of collected samples decrease with high-temperature burn-off. (au) 20 refs.

  7. Synthesis and characterization of oxidic semiconductor alloys; Synthese und Charakterisierung oxidischer Halbleiterlegierungen

    Merita, S.

    2007-02-15

    In the present thesis the possibility for the synthesis of the mixed systems ZnO{sub 1-x}Te{sub x} and Cu{sub 2}O{sub 1-x}S{sub x} by means of reactive RF sputtering deposition is studied. The layers deposed on glass, sapphire, and GaN substrateswere analyzed by X-ray diffraction, optical transmission and reflection measurements, energy-dispersive X-ray analysis, secondary-ion mass spectroscopy, Hall measurements, X-ray reflectometry, scanning electron and scanning force microscopy.

  8. SYNTHESIS AND CHARACTERIZATION OF BIO-BASED POLYESTER POLYOL

    MİTHAT ÇELEBİ

    2016-11-01

    Full Text Available Polyurethanes are versatile polymeric materials and are usually synthesised by isocyanate reactions with polyols. Due to the variety of isocyanates and polyols, particularly polyols, polyurethanes can be easily tailored for wide applications, such as rigid and flexible foams, coatings, adhesives, and elastomers. Considerable efforts have been recently devoted to developing bio-based substitutes for petroleum-based polyuretahanes due to increasing concerns over the depletion of petroleum resources, environment, and sustainability. Polyester polyols based on aliphatic and aromatic dicarboxylic acids are one of the most important materials in polymer technologies. Large volume of plants oils are used as renewable resources to produce various chemicals which are industrially important to make soaps, cosmetic products, surfactants, lubricants, diluents, plasticizers, inks, agrochemicals, composite materials, food industry. This study introduces synthesis and properties of bio-based polyols from different renewable feedstocks including vegetable oils and derivatives. A comparison of bio-based polyol properties with their petroleum-based analogues were investigated.

  9. Synthesis, characterization and radiation processing of carboxymethyl-chitosan

    Kamarudin Bahari; Kamarolzaman Hussein; Kamaruddin Hashim; Khairul Zaman Mohd Dahlan

    2002-01-01

    Chitosan is natural polymer derived from chitin, a polysaccharide found in the exoskeleton of shrimps, crabs, fungi and others. Chitosan is a naturally occurring substance that is chemically similar to cellulose. Chitosan possesses a positive ionic charge give ability to chemically bond with negatively charged fats. Chitosan is soluble in organic acid but insoluble in water. Carboxymethyl-chitosan (cm-chitosan) is a derivative of chitosan which is water-soluble was then prepared by carboxymethylation process of chitosan produced from local shrimp shell. A simple method for synthesis of cm-chitosan has been developed at 55 degree C in aqueous sodium hydroxide / propanol with chloroacetic acid (CAA) or sodium chloroacetate salt (SCA). The modification of chitosan to water-soluble chitosan can be used in hydrogel as anti-bacterial and anti-fungal agent, and it overcome the problem of bad smell using organic acid. (Author)

  10. Synthesis and characterization of a nanocrystalline diamond aerogel

    Pauzauskie, Peter J.; Crowhurst, Jonathan C.; Worsley, Marcus A.; Laurence, Ted A.; Kilcoyne, A. L. David; Wang, Yinmin; Willey, Trevor M.; Visbeck, Kenneth S.; Fakra, Sirine C.; Evans, William J.; Zaug, Joseph M.; Satcher, Jr., Joe H.

    2011-07-06

    Aerogel materials have myriad scientific and technological applications due to their large intrinsic surface areas and ultralow densities. However, creating a nanodiamond aerogel matrix has remained an outstanding and intriguing challenge. Here we report the high-pressure, high-temperature synthesis of a diamond aerogel from an amorphous carbon aerogel precursor using a laser-heated diamond anvil cell. Neon is used as a chemically inert, near-hydrostatic pressure medium that prevents collapse of the aerogel under pressure by conformally filling the aerogel's void volume. Electron and X-ray spectromicroscopy confirm the aerogel morphology and composition of the nanodiamond matrix. Time-resolved photoluminescence measurements of recovered material reveal the formation of both nitrogen- and silicon- vacancy point-defects, suggesting a broad range of applications for this nanocrystalline diamond aerogel.

  11. Synthesis and characterization of nano silver ferrite composite

    Murthy, Y.L.N.; Kondala Rao, T.; Kasi viswanath, I.V.; Singh, Rajendra

    2010-01-01

    We report the synthesis of nano sized silver ferrite composite having the empirical formula AgFeO 2 by a co-precipitation method. The resulting powders are thin platelets, transparent and a rich ruby red in color in transmission. The X-ray diffraction (XRD) powder data consisted of only nine reflections, and the analysis showed the unit cell to be rhombohedral. The powders showed extensive XRD line broadening and the sizes of the crystals are calculated to be in the range 4-36.5 nm. The morphology of the silver ferrite composite studied using scanning electron microscope showed nano sized particles. The particle size is found to increase with increase in annealing temperature. The magnetic behavior, measured using a vibrating sample magnetometer, indicated a change from paramagnetic to ferromagnetic with increase in particle size.

  12. Synthesis, characterization, and reactivity of a uranium(VI) carbene imido oxo complex

    Lu, Erli; Cooper, Oliver J.; McMaster, Jonathan; Lewis, William; Blake, Alexander J.; Liddle, Stephen T. [Nottingham Univ. (United Kingdom). School of Chemistry; Tuna, Floriana; McInnes, Eric J.L. [Manchester Univ. (United Kingdom). School of Chemistry and Photon Science Inst.

    2014-06-23

    We report the uranium(VI) carbene imido oxo complex [U(BIPM{sup TMS})(NMes)(O)(DMAP){sub 2}] (5, BIPM{sup TMS}=C(PPh{sub 2}NSiMe{sub 3}){sub 2}; Mes=2,4,6-Me{sub 3}C{sub 6}H{sub 2}; DMAP=4-(dimethylamino)pyridine) which exhibits the unprecedented arrangement of three formal multiply bonded ligands to one metal center where the coordinated heteroatoms derive from different element groups. This complex was prepared by incorporation of carbene, imido, and then oxo groups at the uranium center by salt elimination, protonolysis, and two-electron oxidation, respectively. The oxo and imido groups adopt axial positions in a T-shaped motif with respect to the carbene, which is consistent with an inverse trans-influence. Complex 5 reacts with tert-butylisocyanate at the imido rather than carbene group to afford the uranyl(VI) carbene complex [U(BIPM{sup TMS})(O){sub 2}(DMAP){sub 2}] (6).

  13. Synthesis, characterization, and reactivity of a uranium(VI) carbene imido oxo complex

    Lu, Erli; Cooper, Oliver J.; McMaster, Jonathan; Lewis, William; Blake, Alexander J.; Liddle, Stephen T. [School of Chemistry, University of Nottingham (United Kingdom); Tuna, Floriana; McInnes, Eric J.L. [School of Chemistry and Photon Science Institute, University of Manchester (United Kingdom)

    2014-06-23

    We report the uranium(VI) carbene imido oxo complex [U(BIPM{sup TMS})(NMes)(O)(DMAP){sub 2}] (5, BIPM{sup TMS}=C(PPh{sub 2}NSiMe{sub 3}){sub 2}; Mes=2,4,6-Me{sub 3}C{sub 6}H{sub 2}; DMAP=4-(dimethylamino)pyridine) which exhibits the unprecedented arrangement of three formal multiply bonded ligands to one metal center where the coordinated heteroatoms derive from different element groups. This complex was prepared by incorporation of carbene, imido, and then oxo groups at the uranium center by salt elimination, protonolysis, and two-electron oxidation, respectively. The oxo and imido groups adopt axial positions in a T-shaped motif with respect to the carbene, which is consistent with an inverse trans-influence. Complex 5 reacts with tert-butylisocyanate at the imido rather than carbene group to afford the uranyl(VI) carbene complex [U(BIPM{sup TMS})(O){sub 2}(DMAP){sub 2}] (6). (copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  14. Synthesis, characterization and reactivity of oxomolybdenum(V) complexes with ONS and NNS donors

    Bhattacharjee, Samiran; Bhattacharyya, Ramgopal

    1995-01-01

    The monomeric oxomolybdenum(V) complexes, (MoOLCl 2 ) 1a-1d (HL=S-benzyl/methyl 3-(2-pyridyl)methylenedithiocarbazate (1a and 1b), or N-methyl-S-benzyl/methyl 3-(2-hydroxyphenyl)methylenedithiocarbazate (1c and 1d) are synthesized by the reaction of MoOCl 5 2- with HL ligands. All these complexes show magnetic moment of about 1.7 B.M. The complexes, 1a and 1b, exhibit rhombic g-tensor anisotropy (like xanthine oxidase) whilst 1c and 1d show axial spectrum. The above complexes undergo irreversible electrochemical reduction furnishing Mo(IV) species and the potentials are dependent on the S-substituents. Reactions of MoOX 5 2- (X=Cl or Br) with H 2 L 1 (H 2 L 1 =S-methyl 3-(5-R-2-hydroxyphenyl)methylenedithiocarbazate) (R=H, CH 3 , Cl, Br) produce complexes of thiolatobridged dimers, (Mo 2 O 2 L 2 1 X 2 ), which show sub-normal magnetic moments at room temperature. The metal centred irreversible oxidation and reduction of these complexes show expected dependence on the R-substituents of the salicyl phenyl ring of the ligands. (author). 40 refs., 2 figs., 3 tabs

  15. Stop Flow Lithography Synthesis and Characterization of Structured Microparticles

    David Baah

    2014-01-01

    Full Text Available In this study, the synthesis of nonspherical composite particles of poly(ethylene glycol diacrylate (PEG-DA/SiO2 and PEG-DA/Al2O3 with single or multiple vias and the corresponding inorganic particles of SiO2 and Al2O3 synthesized using the Stop Flow Lithography (SFL method is reported. Precursor suspensions of PEG-DA, 2-hydroxy-2-methylpropiophenone, and SiO2 or Al2O3 nanoparticles were prepared. The precursor suspension flows through a microfluidic device mounted on an upright microscope and is polymerized in an automated process. A patterned photomask with transparent geometric features masks UV light to synthesize the particles. Composite particles with vias were synthesized and corresponding inorganic SiO2 and Al2O3 particles were obtained through polymer burn-off and sintering of the composites. The synthesis of porous inorganic particles of SiO2 and Al2O3 with vias and overall dimensions in the range of ~35–90 µm was achieved. BET specific surface area measurements for single via inorganic particles were 56–69 m2/g for SiO2 particles and 73–81 m2/g for Al2O3 particles. Surface areas as high as 114 m2/g were measured for multivia cubic SiO2 particles. The findings suggest that, with optimization, the particles should have applications in areas where high surface area is important such as catalysis and sieving.

  16. Synthesis and characterization of Gd-doped magnetite nanoparticles

    Zhang, Honghu; Malik, Vikash; Mallapragada, Surya; Akinc, Mufit

    2017-01-01

    Synthesis of magnetite nanoparticles has attracted increasing interest due to their importance in biomedical and technological applications. Tunable magnetic properties of magnetite nanoparticles to meet specific requirements will greatly expand the spectrum of applications. Tremendous efforts have been devoted to studying and controlling the size, shape and magnetic properties of magnetite nanoparticles. Here we investigate gadolinium (Gd) doping to influence the growth process as well as magnetic properties of magnetite nanocrystals via a simple co-precipitation method under mild conditions in aqueous media. Gd doping was found to affect the growth process leading to synthesis of controllable particle sizes under the conditions tested (0–10 at% Gd"3"+). Typically, undoped and 5 at% Gd-doped magnetite nanoparticles were found to have crystal sizes of about 18 and 44 nm, respectively, supported by X-ray diffraction and transmission electron microscopy. Our results showed that Gd-doped nanoparticles retained the magnetite crystal structure, with Gd"3"+ randomly incorporated in the crystal lattice, probably in the octahedral sites. The composition of 5 at% Gd-doped magnetite was Fe_(_3_−_x_)Gd_xO_4 (x=0.085±0.002), as determined by inductively coupled plasma mass spectrometry. 5 at% Gd-doped nanoparticles exhibited ferrimagnetic properties with small coercivity (~65 Oe) and slightly decreased magnetization at 260 K in contrast to the undoped, superparamagnetic magnetite nanoparticles. Templation by the bacterial biomineralization protein Mms6 did not appear to affect the growth of the Gd-doped magnetite particles synthesized by this method. - Highlights: • Gd-doped magnetite nanoparticles are synthesized via aqueous co-precipitation method under mild conditions. • Gd doping affects growth of magnetite nanoparticles leading to tunable particle size. • Gd-doped magnetite nanoparticles exhibit ferrimagnetic properties.

  17. Synthesis and characterization of CNTs using polypropylene waste as precursor

    Bajad, Ganesh S. [Department of Chemical Engineering, Visvesvaraya National Institute of Technology, Nagpur 440010 (India); Tiwari, Saurabh K. [Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076 (India); Vijayakumar, R.P., E-mail: vijayakumarrp@che.vnit.ac.in [Department of Chemical Engineering, Visvesvaraya National Institute of Technology, Nagpur 440010 (India)

    2015-04-15

    Graphical abstract: - Highlights: • A facile method for producing CNTs from polypropylene waste is proposed. • Optimization of Ni/Mo mole ratio using RSM suggests the adequacy of cubic model. • Process parameters were optimized by RSM using Box–Behnken four factorial design. • Maximum desirability of one suggested that 514% of CNTs would yield over Ni{sub 4}Mo{sub 0.2}MgO{sub 1}. • Increase in Ni/Mo ratio from 0.5 to 20, inner diameter of CNTs decreases from 25 to 2 nm. - Abstract: We study the synthesis of MWCNTs using polypropylene waste as a precursor and Ni/Mo/MgO as a catalyst by the combustion technique. Molar ratios of Ni, Mo and MgO in the Ni/Mo/MgO catalyst were optimized using response surface methodology (RSM) to obtain the maximum yield of CNTs. The mole ratio 4/0.2/1 was found to yield more carbon product. Further, process parameters such as combustion temperature, combustion time, polymer and catalyst weight were optimized by RSM using Box–Behnken three-level and four-factorial design. The best possible combination of process parameters (combustion time of 10 min, combustion temperature of 800 °C, polymer weight of 5 g and catalyst weight of 150 mg) for maximum yield of CNTs was obtained. HRTEM indicates that the diameter of CNTs depends on the catalyst composition used for the synthesis of CNTs. The results of the study indicate a facile method for producing CNTs from polypropylene waste.

  18. Synthesis and characterization of CNTs using polypropylene waste as precursor

    Bajad, Ganesh S.; Tiwari, Saurabh K.; Vijayakumar, R.P.

    2015-01-01

    Graphical abstract: - Highlights: • A facile method for producing CNTs from polypropylene waste is proposed. • Optimization of Ni/Mo mole ratio using RSM suggests the adequacy of cubic model. • Process parameters were optimized by RSM using Box–Behnken four factorial design. • Maximum desirability of one suggested that 514% of CNTs would yield over Ni 4 Mo 0.2 MgO 1 . • Increase in Ni/Mo ratio from 0.5 to 20, inner diameter of CNTs decreases from 25 to 2 nm. - Abstract: We study the synthesis of MWCNTs using polypropylene waste as a precursor and Ni/Mo/MgO as a catalyst by the combustion technique. Molar ratios of Ni, Mo and MgO in the Ni/Mo/MgO catalyst were optimized using response surface methodology (RSM) to obtain the maximum yield of CNTs. The mole ratio 4/0.2/1 was found to yield more carbon product. Further, process parameters such as combustion temperature, combustion time, polymer and catalyst weight were optimized by RSM using Box–Behnken three-level and four-factorial design. The best possible combination of process parameters (combustion time of 10 min, combustion temperature of 800 °C, polymer weight of 5 g and catalyst weight of 150 mg) for maximum yield of CNTs was obtained. HRTEM indicates that the diameter of CNTs depends on the catalyst composition used for the synthesis of CNTs. The results of the study indicate a facile method for producing CNTs from polypropylene waste

  19. Synthesis and structural characterization of manganese olivine lithium phosphate

    Herrera Robles, Joel O. [Basic Science Department, IIT, Universidad Autónoma de Ciudad Juárez, Av. del Charro 460 norte Cd. Juárez, Chih. C.P. 32310 (Mexico); Fuentes Cobas, Luis E. [Centro de Investigación en Materiales Avanzados CIMAV, Complejo Industrial, M. Cervantes 120, Chihuahua C.P. 31109 (Mexico); Díaz de la Torre, Sebastián [Instituto Politécnico Nacional, Centro de Investigación e Innovación Tecnológica CIITEC, Azcapotzalco, México, D.F. C.P. 02250 (Mexico); Camacho Montes, Héctor, E-mail: hcamacho@uacj.mx [Basic Science Department, IIT, Universidad Autónoma de Ciudad Juárez, Av. del Charro 460 norte Cd. Juárez, Chih. C.P. 32310 (Mexico); Elizalde Galindo, José T.; García Casillas, Perla E.; Rodríguez González, Claudia A. [Basic Science Department, IIT, Universidad Autónoma de Ciudad Juárez, Av. del Charro 460 norte Cd. Juárez, Chih. C.P. 32310 (Mexico); Álvarez Contreras, Lorena [Centro de Investigación en Materiales Avanzados CIMAV, Complejo Industrial, M. Cervantes 120, Chihuahua C.P. 31109 (Mexico)

    2015-09-15

    Highlights: • LiMnPO{sub 4} was obtained by sol gel method and crystallization in reducing atmosphere. • Magnetic and electric properties are reported for LiMnPO{sub 4}. • Electrochemical properties are also found and enhanced by adding carbon. • SEM and HRTEM show the submicron powder nature. • The multifunctional behavior of LiMnPO{sub 4} is experimentally demonstrated. - Abstract: The manganese olivine lithium phosphate is a multifunctional material. If carbon is added to form a composite LiMnPO{sub 4}–C, electrochemical properties can be enhanced, making this material a good candidate for battery cathode. High magnetic susceptibility is reported for this compound at room temperature. In this work, the magnetic response was measured through a Field Cooling/Zero Field Cooling technique at temperature below 100 K. Weak ferroelectric properties at room temperature were measured. Even though, the promising applications and the interesting properties of this system, the attention received in the literature is relatively low. The synthesis of this material is difficult because of the rapid manganese oxidation and the need of a reducing atmosphere. In fact, only few authors report the synthesis of the pure phase. In the present work, nanostructured LiMnPO{sub 4} is obtained by sol gel chemical method and according to X-ray diffraction patterns, pure LiMnPO{sub 4} is obtained after calcination in a reducing atmosphere (10% H{sub 2} – 90% Ar). Nanostructured LiMnPO{sub 4} is a material with very interesting properties that deserves attentions.

  20. Sensitization to epithelial antigens in chronic mucosal inflammatory disease. Characterization of human intestinal mucosa-derived mononuclear cells reactive with purified epithelial cell-associated components in vitro.

    Roche, J K; Fiocchi, C; Youngman, K

    1985-01-01

    To explore the auto-reactive potential of cells infiltrating the gut mucosa in idiopathic chronic inflammatory bowel disease, intestinal lamina propria mononuclear cells (LPMC) were isolated, characterized morphologically and phenotypically, and evaluated for antigen-specific reactivity. The last was assessed by quantitating LPMC cytotoxic capabilities against purified, aqueous-soluble, organ-specific epithelial cell-associated components (ECAC) characterized previously. Enzyme-isolated infla...

  1. Synthesis and characterization of magnesium doped cerium oxide for the fuel cell application

    Kumar, Amit; Kumari, Monika; Kumar, Mintu; Kumar, Sacheen; Kumar, Dinesh

    2016-01-01

    Cerium oxide has attained much attentions in global nanotechnology market due to valuable application for catalytic, fuel additive, and widely as electrolyte in solid oxide fuel cell. Doped cerium oxide has large oxygen vacancies that allow for greater reactivity and faster ion transport. These properties make cerium oxide suitable material for SOFCs application. Cerium oxide electrolyte requires lower operation temperature which shows improvement in processing and the fabrication technique. In our work, we synthesized magnesium doped cerium oxide by the co-precipitation method. With the magnesium doping catalytic reactivity of CeO_2 was increased. Synthesized nanoparticle were characterized by the XRD and UV absorption techniques.

  2. Hyperbranched Polyethylenebased Macromolecular Architectures: Synthesis, Characterization, and Selfassembly

    Al-Sulami, Ahlam

    2018-05-01

    "Chain walking” catalytic polymerization CWCP is a powerful tool for the one-pot synthesis of a unique class of hyperbranched polyethylene HBPE-based macromolecules with a controllable molecular weight, topology, and composition. This dissertation focuses on new synthetic routes to prepare HBPE-based macromolecular architectures by combining the CWCP technique with ring opening polymerization ROP, atom–transfer radical polymerization ATRP, and “click” chemistry. Taking advantage of end-functionalized HBPE, and a new ethynyl-soketal star-shape agent, we were able to synthesize different types of the HBPE-based architectures including hyperbranched-on-hyperbranched core-shell nanostructure, and miktoarm-star-HBPE-based block copolymers. The first part of the dissertation provides a general introduction to the synthesis of polyethylene types with controllable structures. Well-defined polyethylene with different macromolecule architectures were synthesized either for academic or industrial purposes. In the second part, the HBPE with different topologies was synthesized by CWCP, using a α-diimine Pd (II) catalyst. The effect of the temperature and pressure on the catalyst activity and polymer properties, including branch content, molecular weight, distribution, and thermal properties were studied. Two series of samples were synthesized: a) serial samples (A) under pressures of 1, 5, and 27 atm at 5˚C, and b) serial samples (B) at temperatures of 5, 15, and 35 ˚C under 5 atm. Proton nuclear magnetic resonance spectroscopy, 1H NMR, and gel permeation chromatography, GPC, analysis were used to calculate the branching content, molecular weight, and distribution, whereas differential scanning calorimetry, DSC, was used to record the melting and glass transition temperatures as well as the degree of the crystallinity. Well-defined HBPE-based core diblock copolymers with predictable amphiphilic properties are studied in the third part of the project. Hyperbranched

  3. Synthesis and electrical characterization of Graphene Oxide films

    Yasin, Muhammad; Tauqeer, T.; Zaidi, Syed M.H.; San, Sait E.; Mahmood, Asad; Köse, Muhammet E.; Canimkurbey, Betul; Okutan, Mustafa

    2015-01-01

    In this work, we have synthesized Graphene Oxide (GO) using modified Hummers method and investigated its electrical properties using parallel plate impedance spectroscopic technique. Graphene Oxide films were prepared using drop casting method on Indium Tin Oxide (ITO) coated glass substrate. Atomic force microscopy was used to characterize the films' microstructure and surface topography. Electrical characterization was carried out using LCR meter in frequency regime (100 Hz to 10 MHz) at different temperatures. AC conductivity σ ac of the films was observed to be varied with angular frequency, ω as ω S , with S < 1. The electrical properties of GO were found to be both frequency and temperature dependent. Analysis showed that GO film contains direct current (DC) and Correlated Barrier Hopping (CBH) conductivity mechanisms at low and high frequency ranges, respectively. Photon absorption and transmittance capability in the visible range and excellent electrical parameters of solution processed Graphene Oxide suggest its suitability for the realization of low cost flexible organic solar cells and organic Thin Film Transistors, respectively. - Highlights: • Synthesize and electrical characterization of Graphene Oxide (GO) Film was undertaken. • Temperature dependent impedance spectroscopy was used for electrical analysis. • AFM was used to characterize films' microstructure and surface topography. • Electrical parameters were found to vary with both temperature and frequency. • GO showed DC and CBH conductivity mechanisms at low and high frequency, respectively

  4. Synthesis and characterization of iron based superconductor Nd-1111

    Alborzi, Z.; Daadmehr, V.

    2018-06-01

    Polycrystalline sample of NdFeAsO0.8F0.2 was prepared by one-step solid-state reaction method. The structural and electrical properties of sample were characterized through XRD pattern and the 4-probe method. The critical temperature was obtained at 56 K. The crystal structure was tetragonal with P4/nmm:2 symmetry group.

  5. Synthesis and characterization of bio-based polyurethane from ...

    Benzoylated tannin prepared by benzoylation of cashewnut husk tannin, was treated with hexame-thylenediisocyanate in the presence of 1,4-butanediol as an extender to prepare thermosetting polyurethane. The sample was characterized using FT–IR and 13C NMR spectra. Thermal, morphological, physico-chemical and ...

  6. Synthesis, characterization and antibacterial screening of 2,4 ...

    Air stable silver Ag(I) complexes of pyrimethamine and trimethoprim drugs have been synthesized and characterized by elemental analysis, Fourier transform infrared (FTIR) and ultraviolet visible (UV-Vis) spectroscopy, and conductivity measurement. The metal complexes formed a three and four coordinate geometry with ...

  7. Synthesis, characterization and self-assembly with gold nanoparticles

    Administrator

    characterization and self-assembly with gold nanoparticles. JUN-BO LI. 1, ... gold surface lead to the enhancement of device prop- erties. 36,37 ... Reactions were monitored by thin-layer ..... plasmon (SP) absorption band (figure 5) of TOAB-.

  8. Synthesis and characterization and antibacterial activity of some ...

    Some new transition metal complexes of ciprofloxacin-imine derived from ciprofloxacin and o-phenylenediamine were synthesized and characterized on the basis of melting point, magnetic moment, conductance measurements, elemental analysis, infrared, UV/Vis, nuclear magnetic resonance spectroscopy, mass spectra ...

  9. Synthesis, characterization and evaluation of biological activities of ...

    Purpose: To synthesize, characterize and investigate the antimicrobial properties of pure and manganese-doped zinc oxide nanoparticles. Method: Un-doped and manganese-doped zinc oxide (Mn-doped ZnO) nanoparticles were prepared using co-precipitation method. The synthesized Mn-doped ZnO nanoparticles were ...

  10. Synthesis and structural characterization of a calcium coordination ...

    gly = glycine) has been isolated from the calcium chloride-glycine-water system and structurally characterized. Each Ca(II) in 1 is eight-coordinated and is bonded to eight oxygen atoms three of which are from terminal water molecules and five ...

  11. Synthesis, characterization and biological activity studies of mixed ...

    The complexes were characterized using some physical techniques such as melting point, solubility, conductivity measurement and spectroscopic analyses such as UV-Visible spectroscopy, Atomic absorption spectroscopy, and Infrared spectroscopy. Based on the physical and spectroscopic results, the coordination of the ...

  12. Barium titanate inverted opals-synthesis, characterization, and optical properties

    Soten, I.; Miguez, H.; Yang, S.M.; Petrov, S.; Coombs, N.; Tetreault, N.; Ozin, G.A. [Toronto Univ., ON (Canada). Dept. of Chemistry; Matsuura, N.; Ruda, H.E. [Toronto Univ., ON (Canada). Dept. of Metallurgy and Materials Science

    2002-01-01

    The engineering of cubic or tetragonal polymorphs of nanocrystalline barium titanate inverted opals has been achieved by thermally induced transformations. Optical characterization demonstrated photonic crystal behavior of the opals. The tuning of the ferroelectric-paraelectric transition around the Curie temperature is shown in this paper. (orig.)

  13. Synthesis, characterization, and bioavailability in rats of ferric phosphate nanoparticles

    Rohner, F.; Ernst, F.O.; Arnold, M.; Hilbe, M.; Biebinger, R.; Ehrensperger, F.; Pratsinis, S.E.; Langhans, W.; Hurrell, R.F.; Zimmermann, M.B.

    2007-01-01

    Particle size is a determinant of iron (Fe) absorption from poorly soluble Fe compounds. Decreasing the particle size of metallic Fe and ferric pyrophosphate added to foods increases Fe absorption. The aim of this study was to develop and characterize nanoparticles of FePO4 and determine their

  14. Synthesis and characterization of the Rhodium (II) citrate complex

    Najjar, R.; Santos, F.S. dos; Seidel, W.

    1987-01-01

    The preparation and characterization of the rhodium (II) citrate is described. Rhodium citrate was prepared by reacting citric acid trihydrated (3,4 g, 16 mmols) with anhydrous rhodium acetate (0,44 g, 1 mmol). Th electronic instruments, thermogravimetric curve and spectrum of rhodium (II) citrate are analysed. (M.J.C.) [pt

  15. Synthesis, surface characterization and optical properties of 3

    3-Thiopropionic acid (TPA) capped ZnS:Cu nanocrystals have been successfully synthesized by simple aqueous method. Powder X-ray diffraction (XRD) studies revealed the particle size to be 4.2 nm. Surface characterization of the nanocrystals by FTIR spectroscopy has been done and the structure for surface bound TPA ...

  16. Synthesis, characterization and antibacterial screening of 2,4 ...

    seafood

    2012-05-15

    May 15, 2012 ... 2Department of Biochemistry and Microbiology, University of Fort Hare, Alice 5700, South Africa. Accepted 23 February, 2012. Air stable silver Ag(I) complexes of pyrimethamine and trimethoprim drugs have been synthesized and characterized by elemental analysis, Fourier transform infrared (FTIR) and ...

  17. Synthesis, characterization and antibacterial activity of aspirin and ...

    Dr J. T. Ekanem

    Novel complexes of Co (11), Ni (11) and Fe (111) with aspirin and paracetamol have synthesized and characterized using infrared, electronic and Hnmr spectral, melting point and conductivity measurements. The two ligands have been found to act as bidentate chelating agents. Aspirin complexes coordinate through the ...

  18. Synthesis and characterization of castor oil-based polyurethane

    Polyurethane (PU) based on polyol, derived from castor oil has been synthesized and characterized for potential use as a base material for electrolytes. Transesterification process of castor oil formed a polyol with hydroxyl value of 190 mg KOH g–1 and molecular weight of 2786 g mol–1. The polyols together with 4 ...

  19. Synthesis, characterization and antimicrobial activities of a Schiff ...

    Complexes of Cu(II), Ni(II) and Mn(II) with a Schiff base derived from condensation reaction of phenylalanine and acetylacetone have been synthesized and characterized analytically and spectroscopically. Melting point of the Schiff base was 188oC and the complexes decompose within a temperature range of 210-242oC.

  20. Detection and Characterization of Reactive Oxygen and Nitrogen Species in Biological Systems by Monitoring Species-Specific Products.

    Hardy, Micael; Zielonka, Jacek; Karoui, Hakim; Sikora, Adam; Michalski, Radosław; Podsiadły, Radosław; Lopez, Marcos; Vasquez-Vivar, Jeannette; Kalyanaraman, Balaraman; Ouari, Olivier

    2018-05-20

    Since the discovery of the superoxide dismutase enzyme, the generation and fate of short-lived oxidizing, nitrosating, nitrating, and halogenating species in biological systems has been of great interest. Despite the significance of reactive oxygen species (ROS) and reactive nitrogen species (RNS) in numerous diseases and intracellular signaling, the rigorous detection of ROS and RNS has remained a challenge. Recent Advances: Chemical characterization of the reactions of selected ROS and RNS with electron paramagnetic resonance (EPR) spin traps and fluorescent probes led to the establishment of species-specific products, which can be used for specific detection of several forms of ROS and RNS in cell-free systems and in cultured cells in vitro and in animals in vivo. Profiling oxidation products from the ROS and RNS probes provides a rigorous method for detection of those species in biological systems. Formation and detection of species-specific products from the probes enables accurate characterization of the oxidative environment in cells. Measurement of the total signal (fluorescence, chemiluminescence, etc.) intensity does not allow for identification of the ROS/RNS formed. It is critical to identify the products formed by using chromatographic or other rigorous techniques. Product analyses should be accompanied by monitoring of the intracellular probe level, another factor controlling the yield of the product(s) formed. More work is required to characterize the chemical reactivity of the ROS/RNS probes, and to develop new probes/detection approaches enabling real-time, selective monitoring of the specific products formed from the probes. Antioxid. Redox Signal. 28, 1416-1432.

  1. Synthesis and characterization of dihexyldithiocarbamate as a chelating agent in extraction of gold(III)

    Fatimah, Soja Siti, E-mail: soja-sf@upi.edu [Departemen Pendidikan Kimia, Universitas Pendidikan Indonesia, Jl. Dr. Setiabudhi No. 229, Bandung 40154 (Indonesia); Department of Chemistry, Faculty of Mathematics and Natural Sciences, Padjadjaran University, Jl. Raya Bandung-Sumedang, Km. 21, Jatinangor (Indonesia); Bahti, Husein H.; Hastiawan, Iwan [Department of Chemistry, Faculty of Mathematics and Natural Sciences, Padjadjaran University, Jl. Raya Bandung-Sumedang, Km. 21, Jatinangor (Indonesia); Permanasari, Anna [Departemen Pendidikan Kimia, Universitas Pendidikan Indonesia, Jl. Dr. Setiabudhi No. 229, Bandung 40154 (Indonesia)

    2016-02-08

    The use of dialkyldithiocarbamates as chelating agents of transition metals have been developing for decades. Many chelating agents have been synthesized and used in the extraction of the metals. Studies on particular aspects of extraction of the metals, such as the effect of increasing hydrophobicity of chelating agents on the effectiveness of the extraction, have been done. However, despite the many studies on the synthesis and applications of this type of chelating agents, interests in the aspect of molecular structure of the synthesized ligands and of their complexes, have been limited. This study aimed at synthesizing and characterizing dihexylthiocarbamate, and using the ligand for the extraction of gold III). Characterization of the ligand and of its metal complex were done by using elemental analysis, DTG, and spectroscopic methods to include NMR, ({sup 1}H, and {sup 13}C), FTIR, and MS-ESI. Data on the synthesis, characterization, and the application of the ligand as a chelating agent are presented.

  2. Synthesis and characterization of dihexyldithiocarbamate as a chelating agent in extraction of gold(III)

    Fatimah, Soja Siti; Bahti, Husein H.; Hastiawan, Iwan; Permanasari, Anna

    2016-02-01

    The use of dialkyldithiocarbamates as chelating agents of transition metals have been developing for decades. Many chelating agents have been synthesized and used in the extraction of the metals. Studies on particular aspects of extraction of the metals, such as the effect of increasing hydrophobicity of chelating agents on the effectiveness of the extraction, have been done. However, despite the many studies on the synthesis and applications of this type of chelating agents, interests in the aspect of molecular structure of the synthesized ligands and of their complexes, have been limited. This study aimed at synthesizing and characterizing dihexylthiocarbamate, and using the ligand for the extraction of gold III). Characterization of the ligand and of its metal complex were done by using elemental analysis, DTG, and spectroscopic methods to include NMR, (1H, and 13C), FTIR, and MS-ESI. Data on the synthesis, characterization, and the application of the ligand as a chelating agent are presented.

  3. Synthesis, characterization and magnetic properties of selected Laves and MAX phases

    Hamm, Christin Maria

    2017-01-01

    In this work the rare-earth free Laves phases Ti 2 M 3 Si with M = Mn, Fe, Co, Ni were synthesized by microwave heating and were structurally and magnetically characterized. Furthermore, the solid solution Ti 2 (Co 1-x Fe x ) 3 Si was synthesized by arc melting and spark plasma sintering, as well as their magnetic behavior was studied. In addition to the Laves phases, the focus was on the synthesis and characterization of aluminum-based MAX phases. For the first time the ternary carbides were prepared by microwave heating. The phase-pure representation of MAX phases was particularly challenging for synthetic solid-state chemistry. The susceptor-assisted microwave heating allows the synthesis of high-quality samples, which was shown in this work on M 2 AlC (M = Ti, V, Cr) and V 4 AlC 3 . Furthermore, for the first time, the doping of these materials with Mn and Fe was successful. In addition to the structural characterization of the new phases, the microstructure and magnetic properties are discussed in this work. Using these doped compounds as well as the compound V 4 AlC 3 , it has been shown that field-activated synthesis, particularly susceptor-assisted microwave heating, are a very good synthesis method for compounds which are hard or sometimes not synthesized by conventional methods.

  4. Synthesis and Characterization of Magnesium Substituted Aluminophosphate Molecular Sieves with AEL Structure

    Benjing Xu; Ling Qian; Xinmei Liu; Chunmin Song; Zifeng Yan

    2004-01-01

    MAPO-11 molecular sieves were synthesized by hydrothermal methods. The influence of precursor of magnesium, Mg/Al ratio, synthesis temperature, synthesis time and the type of template on the formation and properties of MAPO-11 molecular sieves was examined. The samples were characterized by the techniques of X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric/differential thermogravimetric analysis (TG-DGA), etc. The results show that the shape and size of crystal were influenced by the precursor of Mg, the Mg/Al ratio and the type of template, and the TG-DGA analysis shows that MAPO-11 molecular sieves as-synthesized have poor thermal stability.

  5. Synthesis and characterization of boehmites obtained from gibbsite in presence of different environments

    Denigres Filho, Ricardo Wilson Nastari; Rocha, Gisele de Araujo; Vieira-Coelho, Antonio Carlos, E-mail: acvcoelh@usp.br [Universidade de Sao Paulo (LPSS/EP/USP), SP (Brazil). Departamento de Engenharia Metalurgica e de Materiais. Laboratorio de Materias-Primas Particuladas; Montes, Celia Regina [Centro de Energia Nuclear na Agricultura (NUPEGEL/CENA/USP), Piracicaba, SP (Brazil). Nucleo de Pesquisas Geoquimicas e Geofisicas da Listosfera

    2016-05-15

    In this study, results related to boehmite synthesis by hydrothermal processes starting from a Bayer commercial gibbsite are reported. The processes have been conducted from aqueous suspensions with initial acidic or alkaline pH, without or with acetate ion, at 160 deg C for 72h to 168h. The final materials were characterized by X-ray diffraction (XRD), thermal methods (DTA and TGA) and scanning electron microscopy (SEM). The influence of the synthesis conditions on the morphology of the boehmite crystals obtained from the gibbsite at different hydrothermal processes are discussed. (author)

  6. Design of calamitic self-assembling reactive mesogenic units: mesomorphic behaviour and rheological characterization

    Bubnov, Alexej M.; Cigl, Martin; Machado, A.; Pociecha, D.; Hamplová, Věra; Cidade, M.T.

    2017-01-01

    Roč. 44, Aug (2017), s. 1-13 ISSN 0267-8292 R&D Projects: GA ČR GA16-12150S Institutional support: RVO:68378271 Keywords : functional reactive mesogens * liquid crystals * self-assembling behaviour * nematic * smectic * electrorheological fluids Subject RIV: JJ - Other Materials OBOR OECD: Nano-materials (production and properties) Impact factor: 2.661, year: 2016

  7. Synthesis and characterization of solid solutions in ABCO 4 system

    Novoselov, A.; Zimina, G.; Komissarova, L.; Pajaczkowska, A.

    2006-01-01

    Formation of continuous solid solutions with a tetragonal structure of K 2NiF 4-type was investigated by direct solid-state synthesis, carbonate precipitations, the freeze-drying method and the Czochralski crystal growth technique. In the systems of SrLaAlO 4-CaLaAlO 4, SrNdAlO 4-CaNdAlO 4, SrPrAlO 4-CaPrAlO 4, SrLaAlO 4-SrLaGaO 4 and SrLaAlO 4-SrLaFeO 4 solid solutions are formed in the whole concentration range (0.0⩽ x⩽1.0) and in the systems of SrLaAlO 4-SrLaMnO 4 and SrLaAlO 4-SrLaCrO 4 in the limited compositional interval of (0.0⩽ x⩽0.20) and (0.0⩽ x⩽0.25), respectively, with composition dependency of lattice constants following Vegard's law.

  8. Synthesis, characterization and magnetic properties of Fe-Al nanopins

    Zhang, W.S.; Brueck, E.; Li, W.F.; Si, P.Z.; Geng, D.Y.; Zhang, Z.D.

    2005-01-01

    We report the synthesis of Fe-Al nanopins using arc discharge. The morphology and chemical composition of the Fe-Al nanopins were studied by means of X-ray diffraction, X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDX), and high-resolution transmission electron microscopy (HRTEM). The nanopins are composed of a spherical base of about 20-100 nm and a needle-like tip of about several hundred nanometers. EDX and HRTEM studies indicate that the spherical base is mainly composed of α-Fe and FeAl core coated with a thin Al 2 O 3 layer, while the needle-like part contains only Al and O and corresponds to Al 2 O 3 . The formation mechanism of the nanopins is suggestive of a vapor-liquid-solid (VLS) growth process. The as-prepared Fe-Al nanopins show ferromagnetic properties. The temperature dependence of the magnetization at high temperatures indicates the existence of some phase transformations

  9. MOCVD of zirconium oxide thin films: Synthesis and characterization

    Torres-Huerta, A.M.; Dominguez-Crespo, M.A.; Ramirez-Meneses, E.; Vargas-Garcia, J.R.

    2009-01-01

    The synthesis of thin films of zirconia often produces tetragonal or cubic phases, which are stable at high temperatures, but that can be transformed into the monoclinic form by cooling. In the present study, we report the deposition of thin zirconium dioxide films by metalorganic chemical vapor deposition using zirconium (IV)-acetylacetonate as precursor. Colorless, porous, homogeneous and well adherent ZrO 2 thin films in the cubic phase were obtained within the temperature range going from 873 to 973 K. The deposits presented a preferential orientation towards the (1 1 1) and (2 2 0) planes as the substrate temperature was increased, and a crystal size ranging between 20 and 25 nm. The kinetics is believed to result from film growth involving the deposition and aggregation of nanosized primary particles produced during the CVD process. A mismatch between the experimental results obtained here and the thermodynamic prediction was found, which can be associated with the intrinsic nature of the nanostructured materials, which present a high density of interfaces.

  10. MOCVD of zirconium oxide thin films: Synthesis and characterization

    Torres-Huerta, A.M., E-mail: atohuer@hotmail.com [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Unidad Altamira, Instituto Politecnico Nacional, Km. 14.5 Carr. Tampico-Puerto Industrial, C.P. 89600, Altamira, Tamaulipas (Mexico); Dominguez-Crespo, M.A.; Ramirez-Meneses, E. [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Unidad Altamira, Instituto Politecnico Nacional, Km. 14.5 Carr. Tampico-Puerto Industrial, C.P. 89600, Altamira, Tamaulipas (Mexico); Vargas-Garcia, J.R. [ESIQIE, Departamento de Metalurgia y Materiales, Instituto Politecnico Nacional. A.P. 75-876, 07300 Mexico, D.F. (Mexico)

    2009-02-15

    The synthesis of thin films of zirconia often produces tetragonal or cubic phases, which are stable at high temperatures, but that can be transformed into the monoclinic form by cooling. In the present study, we report the deposition of thin zirconium dioxide films by metalorganic chemical vapor deposition using zirconium (IV)-acetylacetonate as precursor. Colorless, porous, homogeneous and well adherent ZrO{sub 2} thin films in the cubic phase were obtained within the temperature range going from 873 to 973 K. The deposits presented a preferential orientation towards the (1 1 1) and (2 2 0) planes as the substrate temperature was increased, and a crystal size ranging between 20 and 25 nm. The kinetics is believed to result from film growth involving the deposition and aggregation of nanosized primary particles produced during the CVD process. A mismatch between the experimental results obtained here and the thermodynamic prediction was found, which can be associated with the intrinsic nature of the nanostructured materials, which present a high density of interfaces.

  11. Synthesis and characterization of several molybdenum chloride cluster compounds

    Beers, W.W.

    1983-06-01

    Investigation into the direct synthesis of Mo/sub 4/Cl/sub 8/(P(C/sub 2/H/sub 5/)/sub 3/)/sub 4/ from Mo/sub 2/(OAc)/sub 4/ led to a synthetic procedure that produces yields greater than 80%. The single-crystal structure disclosed a planar rectangular cluster of molybdenum atoms. Metal-metal bond distances suggest that the long edges of the rectangular cluster should be considered to be single bonds and the short metal-metal bonds to be triple bonds. This view is reinforced by an extended Hueckel calculation. Attempts to add a metal atom to Mo/sub 4/Cl/sub 8/(PR/sub 3/)/sub 4/ to form Mo/sub 5/Cl/sub 10/(PR/sub 3/)/sub 3/ led instead to a compound with the composition Mo/sub 8/Cl/sub 16/(PR/sub 3/)/sub 4/. Solution and reflectance uv-visible spectra and x-ray photoelectron spectra suggest that tetranuclear molybdenum units are present. The facile reaction between Mo/sub 8/Cl/sub 16/(PR/sub 3/)/sub 4/ and PR/sub 3/ imply that the linkage between tetrameric units is weak.

  12. Synthesis and characterization of magnetite nanoparticles from mineral magnetite

    Morel, Mauricio; Martínez, Francisco; Mosquera, Edgar

    2013-01-01

    We have synthesized magnetite nanoparticles with sizes that range from 20 to 30 nm from mineral magnetite roughly 45 μm in size. The procedure consists in the dissolution of the mineral in an acidic medium and subsequent precipitation in a basic medium in the presence of oleic acid. Two experiments were conducted in different gaseous environments. The first was carried out in an environment exposed to air (M1) and the second in an N 2 (M2) environment. The x-ray diffraction results showed a slight difference, which corresponds to the surface oxidation of magnetite. The sizes of the modified nanoparticles were determined through the Scherrer equation and transmission electron microscopy. An organic material mass loss corresponding to 18% was observed through a thermogravimetric analysis. The Fourier transform infrared spectroscopic analysis provides information about the type of bond that is formed on the surface of the nanoparticle, which corresponds to a bidentate chelate. The vibrating sample magnetometer results show a superparamagnetic behavior for sample M1. - Highlights: • A new method for synthesis of nanoparticles from mineral microparticles. • Search agreggate value to the mineral by mean nanoscience. • The stoichiometric ratio of the ions Fe 2+ and Fe 3+ from the mineral magnetite is synergistic

  13. Green synthesis of silver nanoparticles and their characterization by XRD

    Mehta, B. K.; Chhajlani, Meenal; Shrivastava, B. D.

    2017-05-01

    A cost effective and environment friendly technique for green synthesis of silver nanoparticles has been reported. Silver nanoparticles have been synthesized using ethanol extract of fruits of Santalum album (Family Santalaceae), commonly known as East Indian sandalwood. Fruits of S.album were collected and crushed. Ethanol was added to the crushed fruits and mixture was exposed to microwave for few minutes. Extract was concentrated by Buchi rotavaporator. To this extract, 1mM aqueous solution of silver nitrate (AgNO3) was added. After about 24 hr incubation Ag+ ions in AgNO3 solution were reduced to Ag atoms by the extract. Silver nanoparticles were obtained in powder form. X-ray diffraction (XRD) pattern of the prepared sample of silver nanoparticles was recorded The diffractogram has been compared with the standard powder diffraction card of JCPDS silver file. Four peaks have been identified corresponding to (hkl) values of silver. The XRD study confirms that the resultant particles are silver nanoparticles having FCC structure. The average crystalline size D, the value of the interplanar spacing between the atoms, d, lattice constant and cell volume have been estimated. Thus, silver nanoparticles with well-defined dimensions could be synthesized by reduction of metal ions due to fruit extract of S.album.

  14. Synthesis and characterization of magnetite nanoparticles from mineral magnetite

    Morel, Mauricio, E-mail: mmorel@ing.uchile.cl [Laboratorio de Síntesis y Polímeros, Departamento de ciencias de los Materiales, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Santiago (Chile); Laboratorio de Materiales a Nanoescala, Departamento de ciencias de los Materiales, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Avenue Tupper 2069, Santiago (Chile); Martínez, Francisco, E-mail: polimart@ing.uchile.cl [Laboratorio de Síntesis y Polímeros, Departamento de ciencias de los Materiales, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Santiago (Chile); Mosquera, Edgar [Laboratorio de Materiales a Nanoescala, Departamento de ciencias de los Materiales, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Avenue Tupper 2069, Santiago (Chile)

    2013-10-15

    We have synthesized magnetite nanoparticles with sizes that range from 20 to 30 nm from mineral magnetite roughly 45 μm in size. The procedure consists in the dissolution of the mineral in an acidic medium and subsequent precipitation in a basic medium in the presence of oleic acid. Two experiments were conducted in different gaseous environments. The first was carried out in an environment exposed to air (M1) and the second in an N{sub 2} (M2) environment. The x-ray diffraction results showed a slight difference, which corresponds to the surface oxidation of magnetite. The sizes of the modified nanoparticles were determined through the Scherrer equation and transmission electron microscopy. An organic material mass loss corresponding to 18% was observed through a thermogravimetric analysis. The Fourier transform infrared spectroscopic analysis provides information about the type of bond that is formed on the surface of the nanoparticle, which corresponds to a bidentate chelate. The vibrating sample magnetometer results show a superparamagnetic behavior for sample M1. - Highlights: • A new method for synthesis of nanoparticles from mineral microparticles. • Search agreggate value to the mineral by mean nanoscience. • The stoichiometric ratio of the ions Fe{sup 2+} and Fe{sup 3+} from the mineral magnetite is synergistic.

  15. Carbon doped ZnO: Synthesis, characterization and interpretation

    Mishra, D.K.; Mohapatra, J.; Sharma, M.K.; Chattarjee, R.; Singh, S.K.; Varma, Shikha; Behera, S.N.; Nayak, Sanjeev K.; Entel, P.

    2013-01-01

    A novel thermal plasma in-flight technique has been adopted to synthesize nanocrystalline ZnO and carbon doped nanocrystalline ZnO matrix. Transmission electron microscopy (TEM) studies on these samples show the average particle sizes to be around 32 nm for ZnO and for carbon doped ZnO. An enhancement of saturation magnetization in nanosized carbon doped ZnO matrix by a factor of 3.8 has been found in comparison to ZnO nanoparticles at room temperature. Raman measurement clearly indicates the presence of Zn–C complexes surrounded by ZnO matrix in carbon doped ZnO. This indicates that the ferromagnetic signature in carbon doped ZnO arises from the creation of defects or the development of oxy-carbon clusters, in the carbon doped ZnO system. Theoretical studies based on density functional theory also support the experimental analyses. - Highlights: ► Synthesis of nanocrystalline ZnO and carbon doped ZnO matrix by inflight thermal plasma reactor. ► Enhancement of ferromagnetism in nanosized carbon doped ZnO in comparison to ZnO nanoparticles. ► Raman measurement indicates the presence of Zn–C complexes surrounded by ZnO matrix. ► Ferromagnetic signature in carbon doped ZnO arises from the development of oxy-carbon clusters. ► DFT supports experimental evidence of ferromagnetism in C doped ZnO nanoparticles.

  16. Synthesis and characterization of robust magnetic carriers for bioprocess applications

    Kopp, Willian, E-mail: willkopp@gmail.com [Federal University of São Carlos-UFSCar, Graduate Program in Chemical Engineering, Rodovia Washington Luiz, km 235, São Carlos, São Paulo 13565-905 (Brazil); Silva, Felipe A., E-mail: eq.felipe.silva@gmail.com [Federal University of São Carlos-UFSCar, Graduate Program in Chemical Engineering, Rodovia Washington Luiz, km 235, São Carlos, São Paulo 13565-905 (Brazil); Lima, Lionete N., E-mail: lionetenunes@yahoo.com.br [Federal University of São Carlos-UFSCar, Graduate Program in Chemical Engineering, Rodovia Washington Luiz, km 235, São Carlos, São Paulo 13565-905 (Brazil); Masunaga, Sueli H., E-mail: sueli.masunaga@gmail.com [Department of Physics, Montana State University-MSU, 173840, Bozeman, MT 59717-3840 (United States); Tardioli, Paulo W., E-mail: pwtardioli@ufscar.br [Department of Chemical Engineering, Federal University of São Carlos-UFSCar, Rodovia Washington Luiz, km 235, São Carlos, São Paulo 13565-905 (Brazil); Giordano, Roberto C., E-mail: roberto@ufscar.br [Department of Chemical Engineering, Federal University of São Carlos-UFSCar, Rodovia Washington Luiz, km 235, São Carlos, São Paulo 13565-905 (Brazil); Araújo-Moreira, Fernando M., E-mail: faraujo@df.ufscar.br [Department of Physics, Federal University of São Carlos-UFSCar, Rodovia Washington Luiz, km 235, São Carlos, São Paulo 13565-905 (Brazil); and others

    2015-03-15

    Highlights: • Silica magnetic microparticles were synthesized for applications in bioprocesses. • The process to produce magnetic microparticles is inexpensive and easily scalable. • Microparticles with very high saturation magnetization were obtained. • The structure of the silica magnetic microparticles could be controlled. - Abstract: Magnetic carriers are an effective option to withdraw selected target molecules from complex mixtures or to immobilize enzymes. This paper describes the synthesis of robust silica magnetic microparticles (SMMps), particularly designed for applications in bioprocesses. SMMps were synthesized in a micro-emulsion, using sodium silicate as the silica source and superparamagnetic iron oxide nanoparticles as the magnetic core. Thermally resistant particles, with high and accessible surface area, narrow particle size distribution, high saturation magnetization, and with superparamagnetic properties were obtained. Several reaction conditions were tested, yielding materials with saturation magnetization between 45 and 63 emu g{sup −1}, particle size between 2 and 200 μm and average diameter between 11.2 and 15.9 μm, surface area between 49 and 103 m{sup 2} g{sup −1} and pore diameter between 2 and 60 nm. The performance of SMMps in a bioprocess was evaluated by the immobilization of Pseudomonas fluorescens lipase on to octyl modified SMMp, the biocatalyst obtained was used in the production of butyl butyrate with good results.

  17. Synthesis and characterization of micrometer Cu/PVP architectures

    Luo, Huajuan; Zhao, Yanbao; Sun, Lei

    2011-01-01

    Graphical abstract: A simple method for the synthesis of novel micrometer flower-like Cu/PVP architectures was introduced. Highlights: → Micrometer flower-like copper/polyvinylpyrrolidone architectures were obtained by a simple chemical route. → The amount of N 2 H 4 ·H 2 O, the reaction temperature, the molar ratio of CuCl 2 to PVP and different molecular weights of PVP play an important role in the controlling the morphology of the Cu/PVP architectures. → A possible mechanism of the formation of Cu/PVP architectures was discussed. -- Abstract: Micrometer-sized flower-like Cu/polyvinylpyrrolidone (PVP) architectures are synthesized by the reduction of copper (II) salt with hydrazine hydrate in aqueous solution in the presence of PVP capping agent. The resulting Cu/PVP architectures are investigated by UV-vis spectroscopy, transmission electron microscopy (TEM), X-ray powder diffraction (XRD), and scanning electron microscopy (SEM). The Cu/PVP flowers have uniform morphologies with an average diameter of 10 μm, made of several intercrossing plates. The formation of Cu/PVP flowers is a new kinetic control process, and the factors such as the amount of N 2 H 4 ·H 2 O, reaction temperature, molar ratio of CuCl 2 to PVP and molecular weight of PVP have significant effect on the morphology of Cu/PVP architectures. A possible mechanism of the formation of micrometer Cu/PVP architectures was discussed.

  18. Synthesis and characterization of polymeric composites reinforced natural fiber

    Kartini, Ratni; Darmasetiawan, H.; Karo Karo, Aloma; Sudirman

    2002-01-01

    Synthesis of composites between the polymeric matrixes i.e. epoxy and polyester with the natural fibers i.e. banana and straw fibers have been done, which combined each other into four kinds of composites i.e. epoxy-banana, epoxy-straw, polyester-banana, and polyester-straw composites. For each kind of composites, the effect of fibers layers addition into the polymeric matrixes on its mechanical and its microstructure, were learned. It is found that, for all composites except for epoxy-straw, this effect made their tensile strength to be decrease. Epoxy -3-layers straw fibers composite has the highest value that is 45.44 MPa while epoxy -3-layers banana fibers composite has 30.47 MPa for its tensile strength. The lowest tensile strength was belong to polyester -3-layers banana fibers composite, and if it was filled with 3-layers of straw fibers that value become increase to reach 22.18 MPa. Unfortunately, the effect of fibers layer addition is also made their hardness become decrease. It was showed from their microstructures that there were weak bonds between fibers and matrixes. Besides that reason, it also known that fibers distribution in matrixes influences both the tensile strength and the hardness of composite

  19. Synthesis, Characterization and Thermal Diffusivity of Holmium and Praseodymium Zirconates

    Stopyra M.

    2016-06-01

    Full Text Available A2B2O7 oxides with pyrochlore or defected fluorite structure are among the most promising candidates for insulation layer material in thermal barrier coatings. The present paper presents the procedure of synthesis of holmium zirconate Ho2Zr2O7 and praseodymium zirconate Pr2Zr2O7 via Polymerized-Complex Method (PCM. Thermal analysis of precursor revealed that after calcination at relatively low temperature (700°C fine-crystalline, single-phase material is obtained. Thermal diffusivity was measured in temperature range 25-200°C, Ho2Zr2O7 exhibits lower thermal diffusivity than Pr2Zr2O7. Additionally, PrHoZr2O7 was synthesized. The powder in as-calcined condition is single-phase, but during the sintering decomposition of solid solution took place and Ho-rich phase precipitated. This material exhibited the best insulating properties among the tested ones.

  20. Synthesis, Characterization and Properties of Nanoparticles of Intermetallic Compounds

    DiSalvo, Francis J. [Cornell Univ., Ithaca, NY (United States)

    2015-03-12

    The research program from 2010 to the end of the grant focused on understanding the factors important to the synthesis of single phase intermetallic nano-particles (NPs), their size, crystalline order, surface properties and electrochemical activity. The synthetic method developed is a co-reduction of mixtures of single metal precursors by strong, soluble reducing agents in a non-protic solvent, tetrahydrofuran (THF). With some exceptions, the particles obtained by room temperature reduction are random alloys that need to be annealed at modest temperatures (200 to 600 °C) in order to develop an ordered structure. To avoid significant particle size growth and agglomeration, the particles must be protected by surface coatings. We developed a novel method of coating the metal nanoparticles with KCl, a by-product of the reduction reaction if the proper reducing agents are employed. In that case, a composite product containing individual metal nanoparticles in a KCl matrix is obtained. The composite can be heated to at least 600 °C without significant agglomeration or growth in particle size. Washing the annealed product in the presence of catalyst supports in ethylene glycol removes the KCl and deposits the particles on the support. Six publications present the method and its application to producing and studying new catalyst/support combinations for fuel cell applications. Three publications concern the use of related methods to explore new lithium-sulfur battery concepts.