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

NARCIS (Netherlands)

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

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

International Nuclear Information System (INIS)

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.

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

KAUST Repository

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

Synthesis and characterization of triangulene

Science.gov (United States)

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.

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

Energy Technology Data Exchange (ETDEWEB)

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.

Synthesis and Characterization of Colloidal Metal and Photovoltaic Semiconductor Nanocrystals

KAUST Repository

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

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

International Nuclear Information System (INIS)

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)

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

Science.gov (United States)

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.

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

International Nuclear Information System (INIS)

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

Synthesis, properties and reactivity of intramolecular hypercoordinate silicon complexes

International Nuclear Information System (INIS)

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

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

OpenAIRE

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.

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

NARCIS (Netherlands)

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

Synthesis and structural characterization of lithium

Indian Academy of Sciences (India)

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.

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

NARCIS (Netherlands)

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

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

Directory of Open Access Journals (Sweden)

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.

SYNTHESIS, CHARACTERIZATION AND PHOTOCATALYTIC ...

African Journals Online (AJOL)

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 ...

Synthesis of functional nanocrystallites through reactive thermal plasma processing

Directory of Open Access Journals (Sweden)

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.

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

Science.gov (United States)

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

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

Directory of Open Access Journals (Sweden)

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

Synthesis and characterization of six-membered pincer ...

Indian Academy of Sciences (India)

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 ...

Enaminone in heterocyclic synthesis: synthesis of new pyrazolopyrazole, pyrazolothienooxazine and pyrazolothienopyridine derivatives

International Nuclear Information System (INIS)

Hafiz, I.S.; Rahim, M.A.M.A.

2014-01-01

The chemical reactivity of enaminone 2 toward some nucleophilic and electrophilic reagents was investigated. Enaminone 2 was used as a key precursor for the synthesis of many important heterocyclic compounds. The synthesized compounds were characterized by IR, 1H-NMR, MS spectral and elemental analysis. (author)

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

Science.gov (United States)

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.

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

NARCIS (Netherlands)

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

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

International Nuclear Information System (INIS)

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.)

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

African Journals Online (AJOL)

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 ...

Process Improvement of Reactive Dye Synthesis Using Six Sigma Concept

Science.gov (United States)

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).

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

International Nuclear Information System (INIS)

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

Hydrothermal synthesis, characterization and luminescent ...

Indian Academy of Sciences (India)

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.

Synthesis, characterization and comparison of polythiophene ...

Indian Academy of Sciences (India)

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.

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

Indian Academy of Sciences (India)

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.

Synthesis, characterization, antimicrobial activity and molecular ...

African Journals Online (AJOL)

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 ...

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

Energy Technology Data Exchange (ETDEWEB)

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

synthesis and optical characterization of acid-doped polyaniline thin

African Journals Online (AJOL)

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.

Synthesis, Characterization, Antimicrobial Activity and Antioxidant ...

African Journals Online (AJOL)

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-.

Synthesis and characterization of functionalized methacrylates for coatings and biomedical applications

Science.gov (United States)

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

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

Directory of Open Access Journals (Sweden)

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.

Synthesis of Reactive Polymers for Acrolein Capture Using AGET ATRP.

Science.gov (United States)

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.

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

Science.gov (United States)

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.

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

KAUST Repository

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

Photocatalytic semiconductors synthesis, characterization, and environmental applications

CERN Document Server

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.

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

African Journals Online (AJOL)

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.

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

Science.gov (United States)

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.

Synthesis and characterization of dextran-coated iron oxide nanoparticles

Science.gov (United States)

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.

Reactive synthesis of NbAl3 matrix composites

International Nuclear Information System (INIS)

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

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

NARCIS (Netherlands)

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

Synthesis and characterization of magnetite nanoparticles coated with lauric acid

Energy Technology Data Exchange (ETDEWEB)

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.

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

Science.gov (United States)

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

2018-02-01

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

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

KAUST Repository

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.

Synthesis, characterization, thermal

Directory of Open Access Journals (Sweden)

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.

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

Directory of Open Access Journals (Sweden)

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.

Synthesis, characterization and antimicrobial activity of mixed ...

African Journals Online (AJOL)

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, ...

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

African Journals Online (AJOL)

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 ...

Synthesis, Characterization and Applications in Catalysis of Polyoxometalate/Zeolite Composites

Directory of Open Access Journals (Sweden)

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.

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

Directory of Open Access Journals (Sweden)

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.

Reactive Coevaporation Synthesis and Characterization of SrTiO3 Thin Films

Science.gov (United States)

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.

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

Directory of Open Access Journals (Sweden)

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.

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

International Nuclear Information System (INIS)

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

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)

Energy Technology Data Exchange (ETDEWEB)

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.

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

International Nuclear Information System (INIS)

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.)

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

Science.gov (United States)

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.

Synthesis and characterization of organically linked ZnO nanoparticles

Energy Technology Data Exchange (ETDEWEB)

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)

Synthesis and characterization of organically linked ZnO nanoparticles

International Nuclear Information System (INIS)

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)

Synthesis and characterization of germa[n]pericyclynes.

Science.gov (United States)

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.

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

International Nuclear Information System (INIS)

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

Kinetic and mechanistic studies of reactive intermediates in photochemical and transition metal-assisted oxidation, decarboxylation and alkyl transfer reactions

Energy Technology Data Exchange (ETDEWEB)

Carraher, Jack McCaslin [Iowa State Univ., Ames, IA (United States)

2014-01-01

Reactive species like high-valent metal-oxo complexes and carbon and oxygen centered radicals are important intermediates in enzymatic systems, atmospheric chemistry, and industrial processes. Understanding the pathways by which these intermediates form, their relative reactivity, and their fate after reactions is of the utmost importance. Herein are described the mechanistic detail for the generation of several reactive intermediates, synthesis of precursors, characterization of precursors, and methods to direct the chemistry to more desirable outcomes yielding ‘greener’ sources of commodity chemicals and fuels.

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

African Journals Online (AJOL)

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 ...

Synthesis and structural characterization of a calcium coordination ...

Indian Academy of Sciences (India)

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, ...

Polypyrrole-silver Nanocomposite: Synthesis and Characterization

OpenAIRE

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...

Synthesis and characterization of activated lithium fluoride with silver

International Nuclear Information System (INIS)

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)

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

African Journals Online (AJOL)

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 ...

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

International Nuclear Information System (INIS)

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

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

African Journals Online (AJOL)

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.

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

International Nuclear Information System (INIS)

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.

Synthesis, structural and electrical characterizations of thermally ...

African Journals Online (AJOL)

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.

Combustion synthesis and structural characterization of Li–Ti mixed

Indian Academy of Sciences (India)

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.

Synthesis, characterization and magnetic properties of selected Laves and MAX phases

International Nuclear Information System (INIS)

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.

Reactive sputter deposition of boron nitride

International Nuclear Information System (INIS)

Jankowski, A.F.; Hayes, J.P.; McKernan, M.A.; Makowiecki, D.M.

1995-10-01

The preparation of fully dense, boron targets for use in planar magnetron sources has lead to the synthesis of Boron Nitride (BN) films by reactive rf sputtering. The deposition parameters of gas pressure, flow and composition are varied along with substrate temperature and applied bias. The films are characterized for composition using Auger electron spectroscopy, for chemical bonding using Raman spectroscopy and for crystalline structure using transmission electron microscopy. The deposition conditions are established which lead to the growth of crystalline BN phases. In particular, the growth of an adherent cubic BN coating requires 400--500 C substrate heating and an applied -300 V dc bias

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

Indian Academy of Sciences (India)

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.

Surface characterization after subaperture reactive ion beam etching

Energy Technology Data Exchange (ETDEWEB)

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.

Synthesis and characterization of new ionic liquids

International Nuclear Information System (INIS)

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)

The Influence of Sintering Temperature of Reactive Sintered (Ti, MoC-Ni Cermets

Directory of Open Access Journals (Sweden)

Marek Jõeleht

2015-09-01

Full Text Available Titanium-molybdenum carbide nickel cermets ((Ti, MoC-Ni were produced using high energy milling and reactive sintering process. Compared to conventional TiC-NiMo cermet sintering the parameters for reactive sintered cermets vary since additional processes are present such as carbide synthesis. Therefore, it is essential to acquire information about the suitable sintering regime for reactive sintered cermets. One of the key parameters is the final sintering temperature when the liquid binder Ni forms the final matrix and vacancies inside the material are removed. The influence of the final sintering temperature is analyzed by scanning electron microscopy. Mechanical properties of the material are characterized by transverse rupture strength, hardness and fracture toughness.DOI: http://dx.doi.org/10.5755/j01.ms.21.3.7179

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

Science.gov (United States)

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.

Synthesis and characterization of Taurine

Directory of Open Access Journals (Sweden)

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

Design and characterization of metal-thiocyanate coordination polymers

OpenAIRE

Savard, Didier

2018-01-01

This thesis focuses on exploring the synthesis and chemical reactivity of thiocyanate-based building blocks of the type [M(SCN)x]y- for the synthesis of coordination polymers. A series of potassium, ammonium, and tetraalkylammonium metal isothiocyanate salts of the type Qy[M(SCN)x] were synthesized and structurally characterized. Most of the salts were revealed to be isostructural and classic Werner complexes, but for (Et4N)3[Fe(NCS)6] and (n-Bu4N)3[Fe(NCS)6], a solid-state size-dependent cha...

Synthesis and characterization of a nanostructured matrix hydroxyapatite ceramic bone reconstruction

International Nuclear Information System (INIS)

Correa, P.; Camargo, N.H.A.; Silva, D.F.

2012-01-01

The nanostructured ceramics have been shown promise as biomaterials for bone reconstruction. Among calcium phosphates, hydroxyapatite Ca/P ratio = 1.67 mol stands out because of its crystallographic similarity with the mineral bone phase and biocompatibility. This work was based on synthesis and characterization of a nanostructured hydroxyapatite for use in reconstituting bone tissue. The synthesis method for obtaining the bioceramic powder occurred at process of dissolution/precipitation, involving CaO solid/liquid and phosphoric acid required for forming the composition of Ca/P = 1.67 mole. The material recovered from the synthesis was calcined at 900 ° C/2h, providing the hydroxyapatite powder nanometer. This was subjected to mechanical fragmentation process in mill attritor, providing a hydroxyapatite with modified surface morphology. The results presented relate to morphological characterization studies (SEM), mineralogical (XRD), chemical (FTIR) and particle size distribution, using the laser particle size analysis method. Such results showed the formation of hydroxyapatite phase and morphology satisfactory for use in reconstituting bone tissue

Lanthanide phosphonates: Synthesis, thermal stability and magnetic characterization

Energy Technology Data Exchange (ETDEWEB)

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.

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

Institute of Scientific and Technical Information of China (English)

无

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...

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

Science.gov (United States)

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).

SYNTHESIS AND CHARACTERIZATION OF NEW HALOGENATED CURCUMINOIDS

Directory of Open Access Journals (Sweden)

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.

Synthesis and characterization of thermally oxidized ZnO films

Indian Academy of Sciences (India)

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 ...

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

Directory of Open Access Journals (Sweden)

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.

Synthesis and characterization of amorphous cellulose from triacetate of cellulose

International Nuclear Information System (INIS)

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)

Characterization structural and morphology ZSM-5 zeolite by hydrothermal synthesis

International Nuclear Information System (INIS)

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)

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

Science.gov (United States)

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 ...

Polymer Brushes: Synthesis, Characterization, Applications

Science.gov (United States)

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".

Synthesis and Structure Characterization of Phenol-Urea-Formaldehyde Resins in the Presence of Magnesium Oxide as Catalyst

Directory of Open Access Journals (Sweden)

Dong-Bin Fan

2014-08-01

Full Text Available The objective of this research was to provide a useful approach of polymer synthesis for accelerating the fast cure of phenol-urea-formaldehyde (PUF resin as wood adhesive by optimizing its structure and composition. The PUF resins containing high contents of very reactive groups such as para-methylol groups were synthesized by reacting methylolurea, phenol, and formaldehyde in the presence of magnesium oxide (MgO as catalyst. The effects of synthesis parameters including F/(P + U, OH/P, and MgO/P mole ratios on the structure, composition, curing characteristics, and their relationships of PUF resins were investigated. The results indicated that MgO seemed to be an efficacious catalyst for PUF resin synthesis and promote its faster cure. The increase in the F/(P + U mole ratio or/and OH/P mole ratio appeared to be beneficial for the formation of para-methylol groups and cocondensed methylene linkages between phenolic methylol groups and urea units, and for the removal of unreacted urea. In case of Catalyst/P mole ratio, an appropriate dosage of added metal-ion was very important for synthesizing the high-content reactive groups of PUF resins, otherwise leading to the reverse effects.

[Synthesis and Characterization of a Sugar Based Electrolyte for Thin-film Polymer Batteries

Science.gov (United States)

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.

Synthesis and Characterization of Novel Quaternary Thioaluminogermanates

KAUST Repository

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.

Integrated Design and Control of Reactive and Non-Reactive Distillation Processes

DEFF Research Database (Denmark)

Mansouri, Seyed Soheil; Sales-Cruz, Mauricio; Huusom, Jakob Kjøbsted

, an alternative approach is to tackle process design and controllability issues simultaneously, in the early stages of process design. This simultaneous synthesis approach provides optimal/near optimal operation and more efficient control of conventional (non-reactive binary distillation columns) (Hamid et al...... of methodologies have been proposed and applied on various problems to address the interactions between process design and control, and they range from optimization-based approaches to model-based methods (Sharifzadeh, 2013). In this work, integrated design and control of non-reactive distillation, ternary...... reactive distillation processes. The element concept (Pérez Cisneros et al., 1997) is used to translate a ternary system of compounds (A + B ↔ C) to a binary system of element (WA and WB). In the case of multicomponent reactive distillation processes the equivalent element concept is used to translate...

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

Science.gov (United States)

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

Synthesis and characterization of oxidic semiconductor alloys; Synthese und Charakterisierung oxidischer Halbleiterlegierungen

Energy Technology Data Exchange (ETDEWEB)

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.

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

International Nuclear Information System (INIS)

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)

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

Directory of Open Access Journals (Sweden)

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.

Synthesis and characterization of innovative insulation materials

Directory of Open Access Journals (Sweden)

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.

Characterization and reactivity of sodium aluminoborosilicate glass fiber surfaces

Energy Technology Data Exchange (ETDEWEB)

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

Synthesis and Characterization of Two New p-tert-Butylcalix[4]-arene Schiff Bases

Directory of Open Access Journals (Sweden)

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.

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

International Nuclear Information System (INIS)

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)

Graphene optoelectronics synthesis, characterization, properties, and applications

CERN Document Server

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-

Facile microwave synthesis of uniform magnetic nanoparticles with minimal sample processing

Energy Technology Data Exchange (ETDEWEB)

Schneider, Thomas, E-mail: tom.schneider@ubc.ca [Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, BC, V6T 1Z3 Canada (Canada); Löwa, Anna; Karagiozov, Stoyan [Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, BC, V6T 1Z3 Canada (Canada); Sprenger, Lisa [Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, BC, V6T 1Z3 Canada (Canada); TU Dresden, Chair of Magnetofluiddynamics, Measuring and Automation Technology, Dresden, 01062 Germany (Germany); Gutiérrez, Lucía [Instituto Universitario de Nanociencia de Aragón (INA), University of Zaragoza, Zaragoza, 50018 Spain (Spain); Esposito, Tullio; Marten, Gernot; Saatchi, Katayoun [Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, BC, V6T 1Z3 Canada (Canada); Häfeli, Urs O., E-mail: urs.hafeli@ubc.ca [Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, BC, V6T 1Z3 Canada (Canada)

2017-01-01

We present a simple and rapid method for the synthesis of small magnetic nanoparticles (diameters in the order of 5–20 nm) and narrow size distributions (CV's of 20–40%). The magnetite nanoparticles were synthesized in green solvents within minutes and the saturation magnetization of the particles was tunable by changes in the reaction conditions. We show that this particle synthesis method requires minimal processing steps and we present the successful coating of the particles with reactive bisphosphonates after synthesis without washing or centrifugation. We found minimal batch-to-batch variability and show the scalability of the particle synthesis method. We present a full characterization of the particle properties and believe that this synthesis method holds great promise for facile and rapid generation of magnetic nanoparticles with defined surface coatings for magnetic targeting applications. - Highlights: ●Rapid and facile synthesis of magnetic nanoparticles. ●Microwave synthesis in green solvent. ●Magnetite MNPs with small sizes and high saturation magnetization. ●Tunable particle properties depending on heating duration. ●Scalable MNP synthesis.

Microwave hydrothermal synthesis and characterization of PZT 52/48 powders

International Nuclear Information System (INIS)

Teixeira, G.F.; Gasparotto, G.; Santos, N.A.; Zaghete, M.A.; Varela, J.A.; Longo, E.

2009-01-01

Full text: Lead Zirconate Titanate (PZT) is a ceramic witch has great interest because of their ferroelectric, piezoelectric, and other electrical properties. In this work Pb(ZrxTi1-x)O3 powders were synthesized by microwave hydrothermal synthesis (M-H) at 180°C without excess lead content. This method allows obtaining particles whit nanometer size, good stoichiometric controls, high purity and crystalline degree at low temperatures and short times of synthesis. Powders were synthesized with molar concentration of 0.15 mol.L -1 during different times: 30 min, 2, 4, 6 and 8 h. After that the powders were characterized by X-ray diffraction (XRD), Field Emission Gun (FEG) and photoluminescence (PL). Through analysis it is observed that the crystalline phase of PZT is obtained from 2 hours of synthesis and this same time also presents more intense PL emission. (author)

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

International Nuclear Information System (INIS)

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

Electronic, electrical and magnetic ceramics synthesis and characterization

International Nuclear Information System (INIS)

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

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

Directory of Open Access Journals (Sweden)

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

Materials-by-design: computation, synthesis, and characterization from atoms to structures

Science.gov (United States)

Yeo, Jingjie; Jung, Gang Seob; Martín-Martínez, Francisco J.; Ling, Shengjie; Gu, Grace X.; Qin, Zhao; Buehler, Markus J.

2018-05-01

In the 50 years that succeeded Richard Feynman’s exposition of the idea that there is ‘plenty of room at the bottom’ for manipulating individual atoms for the synthesis and manufacturing processing of materials, the materials-by-design paradigm is being developed gradually through synergistic integration of experimental material synthesis and characterization with predictive computational modeling and optimization. This paper reviews how this paradigm creates the possibility to develop materials according to specific, rational designs from the molecular to the macroscopic scale. We discuss promising techniques in experimental small-scale material synthesis and large-scale fabrication methods to manipulate atomistic or macroscale structures, which can be designed by computational modeling. These include recombinant protein technology to produce peptides and proteins with tailored sequences encoded by recombinant DNA, self-assembly processes induced by conformational transition of proteins, additive manufacturing for designing complex structures, and qualitative and quantitative characterization of materials at different length scales. We describe important material characterization techniques using numerous methods of spectroscopy and microscopy. We detail numerous multi-scale computational modeling techniques that complements these experimental techniques: DFT at the atomistic scale; fully atomistic and coarse-grain molecular dynamics at the molecular to mesoscale; continuum modeling at the macroscale. Additionally, we present case studies that utilize experimental and computational approaches in an integrated manner to broaden our understanding of the properties of two-dimensional materials and materials based on silk and silk-elastin-like proteins.

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

Indian Academy of Sciences (India)

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 ...

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

Science.gov (United States)

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

Treatment and characterization of fiber licuri for synthesis of polymeric composites

International Nuclear Information System (INIS)

Oliveira, J.C.; Miranda, C.S.; Carvalho, R.F.; Jose, N.M.; Boaventura, J.S.

2010-01-01

Natural fibers are materials of increasing use of polymeric composites, due to several advantageous properties compared to synthetic fibers: low cost, density, toxicity and excellent biodegradability. Licuri fiber is widely used in the manufacture of handicrafts, with a wide range of possible applications. Before this, characterize the properties of the fiber is of great interest economic, technological and social. This study characterized the fibers in nature, which were washed with water, treated with 5% H 2 SO 4 or 5% NaOH. Techniques were used FTIR, DSC, TGA and XRD, as well as analysis of surface reactivity of the acid and base. All treatments altered the surface of licuri, exposing reactive sites. It was observed that sodium hydroxide licuri changed significantly, as expected. These results are very significant for the recovery of a natural fiber (licuri), abundant in poor regions of the country. (author)

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

KAUST Repository

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.

Studies of carbon deposition and consumption on Ru/TiO2 during Fischer-Tropsch synthesis

International Nuclear Information System (INIS)

Yokomizo, G.; Bell, A.T.; Duncan, T.M.

1986-01-01

Isotropic tracer techniques have been used to characterize the dynamics of carbon deposition on the surface of a Ru/TiO 2 catalyst during Fischer-Tropsch synthesis and 13 C-NMR spectroscopy has been used to characterize the structure of the deposited carbon. Elemental carbon, designated C/sub α/ is formed very rapidly, whereas alkyl carbon, designated C/sub β/ accumulates much more slowly. The influence of catalyst reduction on temperature, reaction conditions, and time under reaction conditions on the surface concentrations and reactivity of C/sub α/ and C/sub β/ will be discussed. It will be shown that C/sub β/ progressively becomes less reactive and may be the precursor to the formation of graphitic carbon

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

Science.gov (United States)

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

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

Science.gov (United States)

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

Design and synthesis of reactive separation systems

Energy Technology Data Exchange (ETDEWEB)

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.

Synthesis and characterization of energetic thermoplastic elastomers for propellant formulations

Directory of Open Access Journals (Sweden)

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.

Synthesis and Characterization of Poly(Amidoamine Dendrimers Encapsulatd 198Au Nanoparticles

Directory of Open Access Journals (Sweden)

R. Ritawidya1,2

2012-12-01

Full Text Available Brachytherapy or internal radiotherapy is one of many methods used for treatment of cancer. This modality requires an agent with radionuclides that emits  or β particle with a proper energy. 198Au (99% β max = 0.96 MeV and t1/2 = 2.69 days is one of radionuclides that has been considered to be effective for the above-mentioned purpose. The purpose of this research was to synthesis and characterize poly(amidoamine (PAMAM G3.0 dendrimers encapsulated 198Au nanoparticles as a new brachytherapy agent. PAMAM G3.0 dendrimers encapsulated 198Au nanoparticles was successfully synthesized by a bottom-up method using sodium borohydride as a reductor. Purification was then performed by a size exclusion chromatography in order to separate large Au nanoparticles that were formed outside the cavity of PAMAM G3.0 dendrimers. Prior to the synthesis of PAMAM G3.0 dendrimers encapsulated 198Au nanoparticles, the synthetic procedure was first established by using a non-radioactive Au. The PAMAM G3.0 dendrimers encapsulated Au nanoparticles produced was then characterized by using an UV-Vis spectroscopy, a transmission electron microscopy (TEM, particle size analyzer (PSA, and an atomic absorption spectroscopy (AAS. Characterization results revealed that PAMAM G3.0 dendrimers encapsulated Au nanoparticles that were prepared from a reaction mixture of PAMAM G3.0 dendrimers and Au HAuCl4 with mol ratio of 2.8, was found to be a proper formula. It produced PAMAM G3.0 dendrimers encapsulated Au nanoparticles with diameter of 1.743 nm, spheris, uniform and drug loading value of 26.34%. This formula was then used in synthesis using radioactive Au, 198Au. Characterization results of PAMAM G3.0 dendrimers encapsulated 198Au nanoparticles gave a radiochemical purity of 99.4% and zero charge.

Synthesis and characterization of photoswitchable fluorescent silica nanoparticles.

Science.gov (United States)

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.

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

Directory of Open Access Journals (Sweden)

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.

Synthesis and characterization of dental composites

Science.gov (United States)

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.

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

Science.gov (United States)

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.

Synthesis, characterization and gas sensing performance of SnO2 ...

Indian Academy of Sciences (India)

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, ...

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

National Research Council Canada - National Science Library

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...

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

Science.gov (United States)

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.

Nano-/micro metallic wire synthesis on Si substrate and their characterization

International Nuclear Information System (INIS)

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

Synthesis and characterization of poly aniline for electrochemical biosensor construction

International Nuclear Information System (INIS)

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)

Synthesis, characterization and initial evaluation of 5-nitro-1-(trifluoromethyl-3H-1λ3,2-benziodaoxol-3-one

Directory of Open Access Journals (Sweden)

Nico Santschi

2014-01-01

Full Text Available The synthesis of 5-nitro-1-(trifluoromethyl-3H-1λ3,2-benziodaoxol-3-one (3, a hypervalent-iodine-based electrophilic trifluoromethylating reagent, is described. Whereas considerations based on cyclic voltammetry and X-ray structural properties would predict an inferior reactivity when compared to the non-nitrated derivative 2, 19F NMR kinetic studies showed that this new derivative is almost one order of magnitude more reactive. Furthermore, differential scanning calorimetry measurements indicated that, in addition, it is also safer to handle.

Synthesis and characterization of Au incorporated Alq3 nanowires

Science.gov (United States)

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.

Synthesis and Characterization of Highly Intercalated Graphite Bisulfate

Science.gov (United States)

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.

Characterizing Nanoparticles Reactivity: Structure-Photocatalytic Activity Relationship

International Nuclear Information System (INIS)

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.

Interaction of UV laser pulses with reactive dusty plasmas

NARCIS (Netherlands)

van de Wetering, F.M.J.H.; Beckers, J.; Nijdam, S.; Oosterbeek, W.; Kovacevic, E.; Berndt, J.

2016-01-01

This contribution deals with the effects of UV photons on the synthesis and transport of nanoparticles in reactive complex plasmas (capacitively coupled RF discharge). First measurements showed that the irradiation of a reactive acetylene-argon plasma with high-energy, ns UV laser pulses (355 nm, 75

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

DEFF Research Database (Denmark)

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...

Green synthesis and characterization of graphene nanosheets

Energy Technology Data Exchange (ETDEWEB)

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.

Green synthesis and characterization of graphene nanosheets

International Nuclear Information System (INIS)

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

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

Energy Technology Data Exchange (ETDEWEB)

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).

Reactive-inspired ball-milling synthesis of an ODS steel: study of the influence of ball-milling and annealing; Synthese et caracterisation d'un acier ODS prepare par un procede inspiredu broyage reactif: etude de l'influence des conditions de broyage et recuit

Energy Technology Data Exchange (ETDEWEB)

Brocq, M.

2010-10-15

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{sub 3} andFe{sub 2}O{sub 3} as starting reactants instead of Y{sub 2}O{sub 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)

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

Science.gov (United States)

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

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

Science.gov (United States)

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.

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

Science.gov (United States)

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.

Synthesis and characterization of liquid crystals and their thermoset films

International Nuclear Information System (INIS)

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.

Boron-based nanostructures: Synthesis, functionalization, and characterization

Science.gov (United States)

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

Synthesis, purification and characterization of [3,5 - T] p-aminobenzoic acid

International Nuclear Information System (INIS)

Corol-Cucu, Delia-Irina; Chiper, Diana; Mihaila, V.; Negoita, N.

2000-01-01

This paper refers to the synthesis, purification and characterization of [3,5-T] p-aminobenzoic acid (PAB,H' vitamine). The p-aminobenzoic acid is used in the treatment of rheumatic arthritis and dermatological affections. The advantage of tritium labelling of p-aminobenzoic acid is that some biomedical important aspects of collagen's behaviour are made clear. The PAB stimulate the grow of intestinal bacteria so necessary to synthesis of some vitamins (bio tine, pantothenic acid). Tritium is the only radioactive isotope of hydrogen. Several steps have to be carried out in the synthesis of the final product as well as to study its biological behavior. For the labelling of PAB one prefers the substitution of bromine from PAB-3,5-Br with tritium because of simplicity of reaction and the easy synthesis of halogen compound. The first step in synthesis is the protection of NH 2 group through acetylation of PAB. After that PAB is bromated into the 3 and 5 position with elementary bromine. The raw compound is purified and recrystallized and characterized through thin layer chromatography.The tritium labelling is performed through substitution of bromine from bromate derivative, using Pd/C (10% Pd) as catalyst and low basic conditions for the neutralization of HBr resulting from reaction. After the separation of PAB-3,5-T through filtration, the catalyst remains on the filter paper and the labelled compound goes in aqueous solution. PAB-3,5-T is purified through thin layer chromatography with the solvent system n-BuOH:NH 4 OH(25%):H 2 O:EtOH (8:1:2:2,5, v/v) with silica gel GF 254 as support. The determination of activity is carried out with LSC (Liquid Scintillation Counter). A 98% purity was determined through TLC in the same conditions while determination of activity distribution was performed with a 2π Berthold scanner with gas running and without window. The chemical concentration has been measured through UV spectrophotometry and by comparing extinction with

Microfluidic Synthesis and Biological Evaluation of Photothermal Biodegradable Copper Sulfide Nanoparticles.

Science.gov (United States)

Ortiz de Solorzano, Isabel; Prieto, Martín; Mendoza, Gracia; Alejo, Teresa; Irusta, Silvia; Sebastian, Victor; Arruebo, Manuel

2016-08-24

The continuous synthesis of biodegradable photothermal copper sulfide nanoparticles has been carried out with the aid of a microfluidic platform. A comparative physicochemical characterization of the resulting products from the microreactor and from a conventional batch reactor has been performed. The microreactor is able to operate in a continuous manner and with a 4-fold reduction in the synthesis times compared to that of the conventional batch reactor producing nanoparticles with the same physicochemical requirements. Biodegradation subproducts obtained under simulated physiological conditions have been identified, and a complete cytotoxicological analysis on different cell lines was performed. The photothermal effect of those nanomaterials has been demonstrated in vitro as well as their ability to generate reactive oxygen species.

Sol – Gel synthesis and characterization of magnesium peroxide nanoparticles

International Nuclear Information System (INIS)

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)

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

Science.gov (United States)

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

Synthesis of Nickel Oxide Nanoparticles Using Gelatine as a Green Template for Photocatalytic Degradation of Dye

OpenAIRE

JAY YANG LEE

2018-01-01

Nickel oxide (NiO) nanoparticles were synthesized through sol-gel method with an environmentally friendly templating agent, which is gelatin. The synthesized NiO were characterized to determine the chemical and physical properties of the nanoparticles. The optimum synthesis parameters were used in photocatalytic degradation of Reactive Black 5 and Acid Yellow 25 dye to determine the catalytic activity of the nanoparticles.

The Synthesis and Characterization of Gold-Core/LDH-Shell Nanoparticles

Science.gov (United States)

Rearick, Colton

In recent years, the field of nanomedicine has progressed at an astonishing rate, particularly with respect to applications in cancer treatment and molecular imaging. Although organic systems have been the frontrunners, inorganic systems have also begun to show promise, especially those based upon silica and magnetic nanoparticles (NPs). Many of these systems are being designed for simultaneous therapeutic and diagnostic capabilities, thus coining the term, theranostics. A unique class of inorganic systems that shows great promise as theranostics is that of layered double hydroxides (LDH). By synthesis of a core/shell structures, e.g. a gold nanoparticle (NP) core and LDH shell, the multifunctional theranostic may be developed without a drastic increase in the structural complexity. To demonstrate initial proof-of-concept of a potential (inorganic) theranostic platform, a Au-core/LDH-shell nanovector has been synthesized and characterized. The LDH shell was heterogeneously nucleated and grown on the surface of silica coated gold NPs via a coprecipitation method. Polyethylene glycol (PEG) was introduced in the initial synthesis steps to improve crystallinity and colloidal stability. Additionally, during synthesis, fluorescein isothiocyanate (FITC) was intercalated into the interlayer spacing of the LDH. In contrast to the PEG stabilization, a post synthesis citric acid treatment was used as a method to control the size and short-term stability. The heterogeneous core-shell system was characterized with scanning electron microscopy (SEM), energy dispersive x-ray spectroscopy (EDX), dynamic light scattering (DLS), and powder x-ray diffraction (PXRD). A preliminary in vitro study carried out with the assistance of Dr. Kaushal Rege's group at Arizona State University was to demonstrate the endocytosis capability of homogeneously-grown LDH NPs. The DLS measurements of the core-shell NPs indicated an average particle size of 212nm. The PXRD analysis showed that PEG

Synthesis and characterization of mangan oxide coated sand from Capkala kaolin

Science.gov (United States)

Destiarti, Lia; Wahyuni, Nelly; Prawatya, Yopa Eka; Sasri, Risya

2017-03-01

Synthesis and characterization of mangan oxide coated sand from quartz sand fraction of Capkala kaolin has been conducted. There were two methods on synthesis of Mangan Oxide Coated Sand (MOCS) from Capkala Kaolin compared in this research. Characterization of MOCS was done by using Scanning Electron Microscope/Energy Dispersive X-Ray Spectrometer (SEM/EDX) and X-Ray Diffraction (XRD). The MOCS was tested to reduce phosphate in laundry waste. The result showed that the natural sand had bigger agregates and a relatively uniform structural orientation while both MOCS had heterogen structural orientation and manganese oxide formed in cluster. Manganese in first and second methods were 1,93% and 2,63%, respectively. The XRD spectrum showed clear reflections at 22,80°, 36,04°, 37,60° and a broad band at 26,62° (SiO2). Based on XRD spectrum, it can be concluded that mineral constituents of MOCS was verified corresponding to pyrolusite (MnO2). The former MOCS could reduce almost 60% while the later could reduce 70% phosphate in laundry waste.

Synthesis and characterization of anisotropic magnetic hydrogels

Energy Technology Data Exchange (ETDEWEB)

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.

Octalithium plumbate as breeding blanket ceramic: Neutronic performances, synthesis and partial characterization

International Nuclear Information System (INIS)

Colominas, S.; Palermo, I.; Abellà, J.; Gómez-Ros, J.M.; Sanz, J.; Sedano, L.

2012-01-01

Highlights: ► Definition of a suitable configuration for the Li 8 PbO 6 breeding blanket design. ► Demonstration of the feasibility of Li 8 PbO 6 as a breeding material. ► Synthesis optimization in the Li 8 PbO 6 production. ► Characterization of Li 8 PbO 6 by X-ray phase analysis is discussed. - Abstract: A neutronic assessment of the performances of a helium-cooled Li 8 PbO 6 breeding blanket (BB) for the conceptual design of a DEMO fusion reactor is given. Different BB configurations have been considered in order to minimize the amount of beryllium required for neutron multiplication, including the use of graphite as reflector material. The calculated neutronic responses: tritium breeding ratio (TBR), power deposition in TF coils and power amplification factor, indicate the feasibility of Li 8 PbO 6 as breeding material. Furthermore, the synthesis and characterization of Li 8 PbO 6 by X-ray phase analysis are also discussed.

Reactive Melt Infiltration Of Silicon Into Porous Carbon

Science.gov (United States)

Behrendt, Donald R.; Singh, Mrityunjay

1994-01-01

Report describes study of synthesis of silicon carbide and related ceramics by reactive melt infiltration of silicon and silicon/molybdenum alloys into porous carbon preforms. Reactive melt infiltration has potential for making components in nearly net shape, performed in less time and at lower temperature. Object of study to determine effect of initial pore volume fraction, pore size, and infiltration material on quality of resultant product.

Synthesis of ascorbic acid enhanced TiO2 photocatalyst: its characterization and catalytic activity in CO2 photoreduction

Directory of Open Access Journals (Sweden)

Mohd Farid Bin Mohd Na'aim

2018-04-01

Full Text Available To date, the development of solar environmental remediation has shifted more emphasis on the green and simple synthesis of catalyst for CO2 photocatalysis process. Herein, TiO2 photocatalyst was successfully synthesized via hydrothermal method. The effects of the different molar ratio of ascorbic acid C6H8O6, (AA added during the preparation of TiO2 nanoparticles were comprehensively studied. The characterization of TiO2 nanocrystals was performed via XRD, XPS, DRUV-vis, and FTIR. The results show the AA loading into TiO2 nanoparticles significantly intensified the XRD spectra of anatase structure. In fact, this feature had signified a reactivity of the photocatalyst in the visible region. In an instance, BET surface area was also enhanced with the highest recorded value of 135.14 m2/g for 0.8AA. Meanwhile, the CO2 photoreduction over synthesized TiO2 had produced the highest amount of HCOOH at 39.3 μmol/g cat for 0.8AA within 6 hours of reaction time. Furthermore, the DRUV-vis analysis had illustrated better light absorption ability of 0.8AA. This profound finding is attributed to the correlation between large surface area, pure anatase phase, and high adsorbed water molecules. Therefore, this study had significantly demonstrated the potential of modified TiO2 with AA in CO2 photocatalysis area while simultaneously presents a green and simple method for TiO2 synthesis.

Colloidal synthesis and characterization of Bi2S3 nanoparticles for photovoltaic applications

International Nuclear Information System (INIS)

Piras, R; Aresti, M; Saba, M; Marongiu, D; Mula, G; Quochi, F; Mura, A; Bongiovanni, G; Cannas, C; Mureddu, M; Ardu, A; Ennas, G; Musinu, A; Calzia, V; Mattoni, A

2014-01-01

Bismuth sulfide is a promising n-type semiconductor for solar energy conversion. We have explored the colloidal synthesis of Bi 2 S 3 nanocrystals, with the aim of employing them in the fabrication of solution-processable solar cells and to replace toxic heavy metals chalcogenides like PbS or CdS, that are currently employed in such devices. We compare different methods to obtain Bi 2 S 3 colloidal quantum dots, including the use of environmentally benign reactants, through organometallic synthesis. Different sizes and shapes were obtained according to the synthesis parameters and the growth process has been rationalized by comparing the predicted morphology with systematic physical-chemistry characterization of nanocrystals by X-ray diffraction, FT-IR spectroscopy, Transmission Electron Microscopy (TEM)

Synthesis and characterization of dihexyldithiocarbamate as a chelating agent in extraction of gold(III)

Energy Technology Data Exchange (ETDEWEB)

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.

Synthesis and characterization of dihexyldithiocarbamate as a chelating agent in extraction of gold(III)

Science.gov (United States)

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.

Synthesis and characterization of M-type barium hexferrite by ultrasonic inter-dispersion of chemical precipitate

International Nuclear Information System (INIS)

Garcia Junior, E.S.; Gomes Junior, G.G.; Ogasawara, T.

2010-01-01

This work is concerned with the study the synthesis and characterization of M-type barium hexaferrite powder by chemical precipitation type and ultrasonic interdispersion of precursor materials Fe(OH) 3 and Ba(OH) 2 ,separately and ultrasonic inter-dispersion, followed by drying and calcining. In order to guide the experimental work was carried out a preliminary thermodynamic analysis of the system Ba-Fe-H 2 O at 25 deg C. The study shows that the phase formation of M-type barium hexaferrite is obtained at a calcination at 1000 deg C, characterized by X-ray diffraction, the grain growth of the final product of synthesis depending on the calcination temperature is visible by SEM. The synthesis method developed in this research is an option to achieve the results that would be obtained if the co-precipitation of ferric and barium hydroxide was thermodynamically possible, where you can get crystallization of barium hexaferrite in a calcination at 1000 deg C. (author)

Synthesis and characterization of boehmites obtained from gibbsite in presence of different environments

Energy Technology Data Exchange (ETDEWEB)

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)

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

Energy Technology Data Exchange (ETDEWEB)

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.

Detection and Characterization of Reactive Oxygen and Nitrogen Species in Biological Systems by Monitoring Species-Specific Products.

Science.gov (United States)

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.

Synthesis and characterization of covalent diphenylalanine nanotube-folic acid conjugates

DEFF Research Database (Denmark)

León, John Jairo Castillo; Rindzevicius, Tomas; Wu, Kaiyu

2014-01-01

Herein, we describe the synthesis and characterization of a covalent nanoscale assembly formed between diphenylalanine micro/nanotubes (PNT) and folic acid (FA). The conjugate was obtained via chemical functionalization through coupling of amine groups of PNTs and carboxylic groups of FA. The sur...... for applications in the detection and diagnosis of cancer or tropical diseases such as leishmaniasis and as a carrier nanosystem delivering drugs to malignant tumors that overexpress folate receptors....

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

Science.gov (United States)

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.

Synthesis and Characterization of Magnesium Substituted Aluminophosphate Molecular Sieves with AEL Structure

Institute of Scientific and Technical Information of China (English)

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.

ROLE OF STEM CELL FACTOR IN THE REACTIVATION OF HUMAN FETAL HEMOGLOBIN

Directory of Open Access Journals (Sweden)

Ugo Testa

2009-06-01

Full Text Available

In humans the switch from fetal to adult  hemoglobin (HbF→ HbA takes place in the perinatal and postnatal period, determining the progressive replacement of HbF with HbA synthesis ( i.e., the relative HbF content in red blood cells decreases from 80-90% to <1%. In spite of more than twenty years of intensive investigations on this classic model, the molecular mechanisms regulating the Hb switching, as well as HbF synthesis in adults, has been only in part elucidated. In adult life, the residual HbF, restricted to F cell compartment, may be reactivated up to 10-20% of total Hb synthesis in various conditions associated with “stress erythropoiesis”: this reactivation represented until now an interesting model of partial Hb switch reverse with important therapeutic implications in patients with hemoglobinopathies, and particularly in -thalassemia.
In vitro and in vivo models have led to the identification of several chemical compounds able to reactivate HbF synthesis in adult erythroid cells. Although the impact of these HbF inducers, including hypomethylating agents, histone deacetylase inhibitors and hydroxyurea, was clear on the natural history of sickle cell anemia, the benefit on the clinical course of -thalassemia was only limited: particularly, the toxicity and the modest increase in γ-globin reactivation indicated the need for improved agents able to induce higher levels of HbF.
In the present review we describe the biologic properties of Stem Cell Factor (SCF, a cytokine sustaining the survival and proliferation of erythroid cells, that at pharmacological doses acts as a potent stimulator of HbF synthesis in adult erythroid cells.

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

International Nuclear Information System (INIS)

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.

Synthesis and characterization of hydroxyapatite crystals: a review study on the analytical methods

NARCIS (Netherlands)

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

High temperature bismuth cuprate superconductors synthesis and characterization

International Nuclear Information System (INIS)

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

Methodology for Design and Analysis of Reactive Distillation Involving Multielement Systems

DEFF Research Database (Denmark)

Jantharasuk, Amnart; Gani, Rafiqul; Górak, Andrzej

2011-01-01

A new methodology for design and analysis of reactive distillation has been developed. In this work, the elementbased approach, coupled with a driving force diagram, has been extended and applied to the design of a reactive distillation column involving multielement (multicomponent) systems...... consisting of two components. Based on this methodology, an optimal design configuration is identified using the equivalent binary-element-driving force diagram. Two case studies of methyl acetate (MeOAc) synthesis and methyl-tert-butyl ether (MTBE) synthesis have been considered to demonstrate...... the successful applications of the methodology. Moreover, energy requirements for various column configurations corresponding to different feed locatio...

Reactive laser-induced ablation as approach to titanium oxycarbide films

International Nuclear Information System (INIS)

Jandova, V.; Fajgar, R.; Dytrych, P.; Kostejn, M.; Drinek, V.; Kupcik, J.

2015-01-01

The IR laser-induced reactive ablation of frozen titanium ethoxide target was studied. The method involves the laser ablation of titanium ethoxide at − 140 °C in gaseous methane (4–50 Pa) atmosphere. This process leads to reactions of the ablative species with hydrocarbon in the gaseous phase. During the ablation of the frozen target excited species interact with methane molecules. The reactive ablation process leads to the formation of a smooth thin film. The thickness of prepared films depends on the number of IR pulses and their composition depends on the pressure of gaseous methane. This reactive IR ablation proceeds as a carbidation process providing nanostructured films with good adhesion to various substrates (glass, metals, KBr) depending on the carbon content in prepared films. Particles are also stabilized by layer preventing their surface oxidation in the atmosphere. The described results are important in the general context for the synthesis of reactive particles in the gas phase. The final products are characterized by spectroscopic, microscopic and diffraction techniques: SEM/EDX, HRTEM, electron diffraction, Raman spectroscopy and XPS. - Highlights: • IR laser ablation of frozen target of titanium ethoxide leads to a reduction in the gaseous methane (4-50 Pa). • Films deposited in methane have Ti/O/C stoichiometry and are oxidized in the atmosphere. • Layers deposited in methane are reduced and have less O in the topmost layers

Reactive laser-induced ablation as approach to titanium oxycarbide films

Energy Technology Data Exchange (ETDEWEB)

Jandova, V., E-mail: jandova@icpf.cas.cz; Fajgar, R.; Dytrych, P.; Kostejn, M.; Drinek, V.; Kupcik, J.

2015-09-01

The IR laser-induced reactive ablation of frozen titanium ethoxide target was studied. The method involves the laser ablation of titanium ethoxide at − 140 °C in gaseous methane (4–50 Pa) atmosphere. This process leads to reactions of the ablative species with hydrocarbon in the gaseous phase. During the ablation of the frozen target excited species interact with methane molecules. The reactive ablation process leads to the formation of a smooth thin film. The thickness of prepared films depends on the number of IR pulses and their composition depends on the pressure of gaseous methane. This reactive IR ablation proceeds as a carbidation process providing nanostructured films with good adhesion to various substrates (glass, metals, KBr) depending on the carbon content in prepared films. Particles are also stabilized by layer preventing their surface oxidation in the atmosphere. The described results are important in the general context for the synthesis of reactive particles in the gas phase. The final products are characterized by spectroscopic, microscopic and diffraction techniques: SEM/EDX, HRTEM, electron diffraction, Raman spectroscopy and XPS. - Highlights: • IR laser ablation of frozen target of titanium ethoxide leads to a reduction in the gaseous methane (4-50 Pa). • Films deposited in methane have Ti/O/C stoichiometry and are oxidized in the atmosphere. • Layers deposited in methane are reduced and have less O in the topmost layers.

Synthesis and characterization of fluorine compounds

International Nuclear Information System (INIS)

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)

Synthesis and processing of composites by reactive metal penetration

Energy Technology Data Exchange (ETDEWEB)

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.

Synthesis characterization, and properties of rubber lattices; a review

International Nuclear Information System (INIS)

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)

Boronate esters: Synthesis, characterization and molecular base receptor analysis

Science.gov (United States)

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.

Synthesis and Characterization of Biscoumarin and Benzopyrano Dicoumarin Derivatives

International Nuclear Information System (INIS)

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)

Synthesis and characterization of the polyaniline dopant Schiff base

Directory of Open Access Journals (Sweden)

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

Determination of reactive oxygen species from ZnO micro-nano structures with shape-dependent photocatalytic activity

Energy Technology Data Exchange (ETDEWEB)

He, Weiwei; Zhao, Hongxiao; Jia, Huimin [Key Laboratory of Micro-Nano Materials for Energy Storage and Conversion of Henan Province, Institute of Surface Micro and Nano Materials, Xuchang University, Henan 461000 (China); Yin, Jun-Jie [Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, College Park, MD 20740 (United States); Zheng, Zhi, E-mail: zhengzhi99999@gmail.com [Key Laboratory of Micro-Nano Materials for Energy Storage and Conversion of Henan Province, Institute of Surface Micro and Nano Materials, Xuchang University, Henan 461000 (China)

2014-05-01

Graphical abstract: ZnO micro/nano structures with shape dependent photocatalytic activity were prepared by hydrothermal reaction. The generations of hydroxyl radical, superoxide and singlet oxygen from irradiated ZnO were identified precisely by electron spin resonance spectroscopy. The type of reactive oxygen species was determined by band gap structure of ZnO. - Highlights: • ZnO micro/nano structures with different morphologies were prepared by solvothermal reaction. • Multi-pod like ZnO structures exhibited superior photocatalytic activity. • The generations of hydroxyl radical, superoxide and singlet oxygen from irradiated ZnO were characterized precisely by electron spin resonance spectroscopy. • The type of reactive oxygen species was determined by band gap structure of ZnO. - Abstract: ZnO micro/nano structures with different morphologies have been prepared by the changing solvents used during their synthesis by solvothermal reaction. Three typical shapes of ZnO structures including hexagonal, bell bottom like and multi-pod formed and were characterized by scanning electron microscopy and X-ray diffraction. Multi pod like ZnO structures exhibited the highest photocatalytic activity toward degradation of methyl orange. Using electron spin resonance spectroscopy coupled with spin trapping techniques, we demonstrate an effective way to identify precisely the generation of hydroxyl radicals, superoxide and singlet oxygen from the irradiated ZnO multi pod structures. The type of reactive oxygen species formed was predictable from the band gap structure of ZnO. These results indicate that the shape of micro-nano structures significantly affects the photocatalytic activity of ZnO, and demonstrate the value of electron spin resonance spectroscopy for characterizing the type of reactive oxygen species formed during photoexcitation of semiconductors.

Determination of reactive oxygen species from ZnO micro-nano structures with shape-dependent photocatalytic activity

International Nuclear Information System (INIS)

He, Weiwei; Zhao, Hongxiao; Jia, Huimin; Yin, Jun-Jie; Zheng, Zhi

2014-01-01

Graphical abstract: ZnO micro/nano structures with shape dependent photocatalytic activity were prepared by hydrothermal reaction. The generations of hydroxyl radical, superoxide and singlet oxygen from irradiated ZnO were identified precisely by electron spin resonance spectroscopy. The type of reactive oxygen species was determined by band gap structure of ZnO. - Highlights: • ZnO micro/nano structures with different morphologies were prepared by solvothermal reaction. • Multi-pod like ZnO structures exhibited superior photocatalytic activity. • The generations of hydroxyl radical, superoxide and singlet oxygen from irradiated ZnO were characterized precisely by electron spin resonance spectroscopy. • The type of reactive oxygen species was determined by band gap structure of ZnO. - Abstract: ZnO micro/nano structures with different morphologies have been prepared by the changing solvents used during their synthesis by solvothermal reaction. Three typical shapes of ZnO structures including hexagonal, bell bottom like and multi-pod formed and were characterized by scanning electron microscopy and X-ray diffraction. Multi pod like ZnO structures exhibited the highest photocatalytic activity toward degradation of methyl orange. Using electron spin resonance spectroscopy coupled with spin trapping techniques, we demonstrate an effective way to identify precisely the generation of hydroxyl radicals, superoxide and singlet oxygen from the irradiated ZnO multi pod structures. The type of reactive oxygen species formed was predictable from the band gap structure of ZnO. These results indicate that the shape of micro-nano structures significantly affects the photocatalytic activity of ZnO, and demonstrate the value of electron spin resonance spectroscopy for characterizing the type of reactive oxygen species formed during photoexcitation of semiconductors

Synthesis, structure characterization and catalytic activity of nickel tungstate nanoparticles

International Nuclear Information System (INIS)

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

2012-01-01

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

Synthesis, structure characterization and catalytic activity of nickel tungstate nanoparticles

Energy Technology Data Exchange (ETDEWEB)

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

2012-12-15

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

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

Science.gov (United States)

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.

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

KAUST Repository

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.

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

KAUST Repository

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.

Synthesis, characterization and magnetic properties of room-temperature nanofluid ferromagnetic graphite

OpenAIRE

Souza, N. S.; Sergeenkov, S.; Speglich, C.; Rivera, V. A. G.; Cardoso, C. A.; Pardo, H.; Mombru, A. W.; Rodrigues, A. D.; de Lima, O. F.; Araujo-Moreira, F. M.

2009-01-01

We report the chemical synthesis route, structural characterization, and physical properties of nanofluid magnetic graphite (NFMG) obtained from the previously synthesized bulk organic magnetic graphite (MG) by stabilizing the aqueous ferrofluid suspension with an addition of active cationic surfactant. The measured magnetization-field hysteresis curves along with the temperature dependence of magnetization confirmed room-temperature ferromagnetism in both MG and NFMG samples. (C) 2009 Americ...

Electrochemical synthesis and characterization of copper (I oxide

Directory of Open Access Journals (Sweden)

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.

Applying flow chemistry: methods, materials, and multistep synthesis.

Science.gov (United States)

McQuade, D Tyler; Seeberger, Peter H

2013-07-05

The synthesis of complex molecules requires control over both chemical reactivity and reaction conditions. While reactivity drives the majority of chemical discovery, advances in reaction condition control have accelerated method development/discovery. Recent tools include automated synthesizers and flow reactors. In this Synopsis, we describe how flow reactors have enabled chemical advances in our groups in the areas of single-stage reactions, materials synthesis, and multistep reactions. In each section, we detail the lessons learned and propose future directions.

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.

OpenAIRE

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...

Synthesis and Characterization of Thermoelectric Oxides at Macro- and Nano-scales

Science.gov (United States)

Ma, Feiyue

Thermoelectric materials can directly convert a temperature difference into electrical voltage and vice versa. Due to this unique property, thermoelectric materials are widely used in industry and scientific laboratories for temperature sensing and thermal management applications. Waste heat harvesting, another potential application of thermoelectric materials, has long been limited by the low conversion efficiency of the materials. Potential high temperature applications, such as power plant waste heat harvesting and combustion engine exhaust heat recovery, make thermoelectric oxides a very promising class of thermoelectric materials. In this thesis, the synthesis and characterization of thermoelectric oxide materials are explored. In the first part of this thesis, the measurement methodologies and instrumentation processes employed to investigate different thermoelectric properties, such as the Seebeck coefficient and carrier concentration at the bulk scale and the thermal conductivity at the nanoscale, are detailed. Existing scientific and engineering challenges associated with these measurements are also reviewed. To overcome such problems, original parts and methodologies have been designed. Three fully functional systems were ultimately developed for the characterization of macroscale thermoelectric properties as well as localized thermal conductivity. In the second part of the thesis, the synthesis of NaxCo 2O4, a thermoelectric oxide material, is discussed. Modification of both composition and structure were carried out so as to optimize the thermoelectric performance of NaxCo2O4. Nanostructuring methods, such as ball milling, electrospinning, auto-combustion synthesis, and core-shell structure fabrication, have been developed to refine the grain size of NaxCo2O4 in order to reduce its thermal conductivity. However, the structure of the nanostructured materials is very unstable at high temperature and limited improvement on thermoelectric performance is

Synthesis and characterization of redox-active ferric nontronite

Energy Technology Data Exchange (ETDEWEB)

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.

Synthesis and characterization of magnesium doped cerium oxide for the fuel cell application

International Nuclear Information System (INIS)

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.

Synthesis and Characterization of High Aluminum Zeolite X from Technical Grade Materials

Directory of Open Access Journals (Sweden)

Seyed Kamal Masoudian

2013-06-01

Full Text Available Zeolites are widely used as ion exchangers, adsorbents, separation materials and catalyst due to their well-tailored and highly-reproducible structures; therefore, the synthesis of zeolite from low grade resources can be interested. In the present work, high aluminum zeolite X was prepared from mixing technical grade sodium aluminate and sodium silicate solutions at temperatures between 70°C and 100°C. The synthesized zeolite X was characterized by SEM and X-ray methods according to ASTM standard procedures. The results showed that aging of the synthesis medium at the room temperature considerably increased the selectivity of zeolite X formation. On the other hand, high temperature of reaction mixture during crystallization formed zeolite A in the product; therefore, it decreased the purity of zeolite X. In addition, it was found that increasing H2O/Na2O and decreasing Na2O/SiO2 molar ratios in the reaction mixture resulted product with higher purity. © 2013 BCREC UNDIP. All rights reservedReceived: 7th January 2013; Revised: 7th April 2013; Accepted: 19th April 2013[How to Cite: Masoudian, S. K., Sadighi, S., Abbasi, A. (2013. Synthesis and Characterization of High Alu-minum Zeolite X from Technical Grade Materials. Bulletin of Chemical Reaction Engineering & Catalysis, 8 (1: 54-60. (doi:10.9767/bcrec.8.1.4321.54-60][Permalink/DOI: http://dx.doi.org/10.9767/bcrec.8.1.4321.54-60] | View in  |

New Dilated LMI Characterization for the Multiobjective Full-Order Dynamic Output Feedback Synthesis Problem

Directory of Open Access Journals (Sweden)

Zrida Jalel

2010-01-01

Full Text Available This paper introduces new dilated LMI conditions for continuous-time linear systems which not only characterize stability and performance specifications, but also, performance specifications. These new conditions offer, in addition to new analysis tools, synthesis procedures that have the advantages of keeping the controller parameters independent of the Lyapunov matrix and offering supplementary degrees of freedom. The impact of such advantages is great on the multiobjective full-order dynamic output feedback control problem as the obtained dilated LMI conditions always encompass the standard ones. It follows that much less conservatism is possible in comparison to the currently used standard LMI based synthesis procedures. A numerical simulation, based on an empirically abridged search procedure, is presented and shows the advantage of the proposed synthesis methods.

Reactive Arthritis

Directory of Open Access Journals (Sweden)

Eren Erken

2013-06-01

Full Text Available Reactive arthritis is an acute, sterile, non-suppurative and inflammatory arthropaty which has occured as a result of an infectious processes, mostly after gastrointestinal and genitourinary tract infections. Reiter syndrome is a frequent type of reactive arthritis. Both reactive arthritis and Reiter syndrome belong to the group of seronegative spondyloarthropathies, associated with HLA-B27 positivity and characterized by ongoing inflammation after an infectious episode. The classical triad of Reiter syndrome is defined as arthritis, conjuctivitis and urethritis and is seen only in one third of patients with Reiter syndrome. Recently, seronegative asymmetric arthritis and typical extraarticular involvement are thought to be adequate for the diagnosis. However, there is no established criteria for the diagnosis of reactive arthritis and the number of randomized and controlled studies about the therapy is not enough. [Archives Medical Review Journal 2013; 22(3.000: 283-299

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

International Nuclear Information System (INIS)

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.

Synthesis and characterization of boron nitrides nanotubes

International Nuclear Information System (INIS)

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)

Magnetic ionic liquids: synthesis and characterization

International Nuclear Information System (INIS)

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)

Controlling Magnetic and Ferroelectric Order Through Geometry: Synthesis, Ab Initio Theory, Characterization of New Multi-Ferric Fluoride Materials

Energy Technology Data Exchange (ETDEWEB)

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.

Synthesis and characterization of iron-cobalt (FeCo) alloy nanoparticles supported on carbon

DEFF Research Database (Denmark)

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...

Synthesis, purification and physico-chemical characterization of the deuterized chloroform

International Nuclear Information System (INIS)

Mihaila, Vasile; Chiper, Diana

1999-01-01

This work refers to deuterized chloroform synthesis and purification methods. Three preparation methods of deuterized chloroform are presented. In the first method the direct chlorination of methane (CH 4 + 3Cl 2 ) in the presence of light and in an oxygen-free atmosphere results in CHCl 3 + 3HCl. The method's drawback is that the resulting product is impure, being obtained also secondary chlorinated compounds, such as CHCl, CH 2 Cl 2 and CCl 4 . The second method consists in chlorination of acetaldehyde or acetone, in basic catalysis and in halogen excess (α substitution with direct synthesis of trihalogen compound), followed by a haloform reaction (hydrolytic splitting) in the presence of chlorinated lime. This method makes use of decarbolyzing of trichlor acetate acid (as a sodium salt), what results in CL 3 CH + NaHCO 3 . This method is the most suitable for the deuterized chloroform synthesis, since the reaction takes place in absence of other hydrogen atoms (protons) and in deuterized water of 99.87% purity, according to the following reaction: Cl 3 C-COONa → (D 2 O) → Cl 2 CD + NaDCO 3 . Another advantage is that this method avoids the synthesis of secondary products, which could entail additional purifications (distillations, rectification, a.s.o.). The deuterized chloroform is separated from the deuterized sodium bicarbonate aqueous solution by washing with deuterized water, in a liquid to liquid separating funnel. After separation, deuterized chloroform is dried in nitrogen atmosphere. The characterization of the final product is carried out by nuclear magnetic resonance spectrometry. (authors)

Chemical synthesis, characterization and evaluation of antimicrobial properties of Cu and its oxide nanoparticles

CSIR Research Space (South Africa)

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...

Synthesis and characterization of new polyamino-cyclodextrin materials.

Science.gov (United States)

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.

Nano-ilmenite FeTiO3 : synthesis and characterization

OpenAIRE

Raghavender, A. T.; Hoa Hong, Nguyen; Lee, Kyu Joon; Jung, Myung-Hwa; Skoko, Z.; Vasilevskiy, Mikhail; Cerqueira, M. F.; Samantilleke, A. P.

2013-01-01

In general, ilmenite FeTiO3 is synthesized by solid-state reaction at very high pressure and high temperature. Synthesis of FeTiO3 is not an easy task as the Fe2+ ions are not stable. Therefore, it is really challenging to prepare this material. In this work nano-ilmenite FeTiO3 was synthesized by the sol-gel method. Structural, optical and magnetic characterizations were performed. The bandgap of FeTiO3 was determined to be 2.8 eV showing FeTiO3 as suitable wide bandgap material for technolo...

Novel, one-step synthesis of zwitterionic polymer nanoparticles via distillation-precipitation polymerization and its application for dye removal membrane.

Science.gov (United States)

Ibrahim, G P Syed; Isloor, Arun M; Inamuddin; Asiri, Abdullah M; Ismail, Norafiqah; Ismail, Ahmed Fauzi; Ashraf, Ghulam Md

2017-11-21

In this work, poly(MBAAm-co-SBMA) zwitterionic polymer nanoparticles were synthesized in one-step via distillation-precipitation polymerization (DPP) and were characterized. [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide (SBMA) as monomer and N, N'-methylene bis(acrylamide) (MBAAm) as cross-linker are used for the synthesis of nanoparticles. As  far as our knowledge, this is the first such report on the synthesis of poly(MBAAm-co-SBMA) nanoparticles via DPP. The newly synthesized nanoparticles were further employed for the surface modification of polysulfone (PSF) hollow fiber membranes for dye removal. The modified hollow fiber membrane exhibited the improved permeability (56 L/ m 2 h bar) and dye removal (>98% of Reactive Black 5 and >80.7% of Reactive orange 16) with the high permeation of salts. Therefore, the as-prepared membrane can have potential application in textile and industrial wastewater treatment.

Synthesis and characterization of N-t-BOC protected pyrrole-sulfur oligomers and polymers

NARCIS (Netherlands)

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

Design and synthesis of reactive separation systems. Final report

Energy Technology Data Exchange (ETDEWEB)

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.

Synthesis and Characterization of ω-Halogenated Poly(dimethyl siloxane

Directory of Open Access Journals (Sweden)

Mojtaba Farrokhi

2014-02-01

Full Text Available Poly(dimethyl siloxane (PDMS has received special attention due to its unique properties such as high surface tension, high gas permeability, high hydrophobicity, high chain flexibility at room temperature, good biocompatibility and very low glass transition temperature. One of the simplest methods to impart these properties in copolymers is to use PDMS as a macroinitiator in the controlled radical polymerization. In the present study, hydroxyl-ω PDMS was characterized by FTIR, 1H NMR and GPC analyses. The results showed that there is an impurity present in the commercial hydroxyl-ω PDMS. Functionalization reactions were used to investigate the reactivity of the impurities. Hydroxyl-terminated PDMS was brominated via 2-bromopropionyl bromide and α-bromoisobutyryl bromide. Brominated PDMS, used as a macroinitiator in the atom transfer radical polymerization, was then iodinated by sodium iodide in anhydrous acetone as a solvent to prepare iodinated PDMS. Bromination and iodination were verified by FTIR, 1H NMR and GPC analyses. GPC results showed that a high molecular weight impurity present in the sample can be removed after functionalization and purification of PDMS though there may be still impurities remain in the purified product. 1H NMR spectrum of the brominated and iodinated PDMS showed that the peaks related to the impurity do not show any change in intensity and chemical shift in comparison with those appeared in the 1H NMR spectrum of the hydroxyl-ω PDMS, indicating that impure species are not reactive in chemical modifications. In other words, these impurity species do not have any hydroxyl reactive functional group.

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

International Nuclear Information System (INIS)

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.

N-Acyliminium Intermediates in Solid-Phase Synthesis

DEFF Research Database (Denmark)

Quement, Sebastian Thordal le; Petersen, Rico; Meldal, M.

2010-01-01

N-Acyliminium ions are powerful intermediates in synthetic organic chemistry. Examples of their use are numerous in solution-phase synthesis, but there are unmerited few reports on these highly reactive electrophiles in solid-phase synthesis. The present review covers the literature to date and i...

Synthesis and characterization of copper nanoparticles by using the exploding wire method

International Nuclear Information System (INIS)

Das, Rashmita; Das, Basanta Kumar; Shyam, Anurag

2012-01-01

During the past few years, the synthesis of copper nanoparticles has attracted much attention because of their huge potential for replacing the expensive nano silver inks utilized in conductive printing. This opens a new possibility in printed electronics. Copper-based inkjet inks can be used to form various devices such as solar cells, RF identification tags and electroluminescence devices. This paper describes controlled synthesis of pure copper nanoparticles, mainly by using the exploding wire method. A wire of 0.26 mm in diameter was exploded in a nitrogen environment. The sample was characterized by using X-ray diffraction (XRD) and atomic force microscopy (AFM). XRD revealed the presence of pure copper and AFM revealed the presence of nanoparticles with an average size of 55 nm.

Evaluation of synthetic zeolite as engineering passive permeable reactive barrier

International Nuclear Information System (INIS)

Ibrahim, O.A.A.

2011-01-01

The presence of toxic pollutants in groundwater brings about significant changes in the properties of water resources and has to be avoided in order to preserve the environmental quality. Heavy metals are among the most dangerous inorganic water pollutants, that related to many anthropogenic sources and their compounds are extremely toxic. The treatment of contaminated groundwater is among the most difficult and expensive environmental problems. Over the past years, permeable reactive barriers have provided an increasingly important role in the passive insitu treatment of contaminated groundwater. There are a large number of materials that are able to immobilize contaminants by sorption, including granulated active carbon, zeolite, montmorillonite, peat, compost, sawdust, etc. Zeolite X is a synthetic counterpart of the naturally occurring mineral Faujasite. It has one of the largest cavities and cavity entrances of any known zeolites. The main aim of this work is to examine the possibility of using synthetic zeolite X as an engineering permeable reactive barrier to remove heavy metals from a contaminated groundwater. Within this context, the following investigations were carried out: 1. Review on the materials most commonly used as engineered permeable reactive barriers to identify the important features to be considered in the examination of the proposed permeable reactive barrier material (zeolite X). 2. Synthesis of zeolite X and characterization of the synthesized material using different techniques. 3. Batch tests were carried out to characterize the equilibrium and kinetic sorption properties of the synthesized zeolite X towards the concerned heavy metals; zinc and cadmium ions. 4. Column tests were also performed to determine the design factors for permeable reactive barrier against zinc and cadmium ions solutions.Breakthrough curves measured in such experiments used to determine the hydrodynamic dispersion coefficients for both metal ions. 5. Analytical

Reactivity of halide and pseudohalide ligands

International Nuclear Information System (INIS)

Kukushkin, Yu.N.

1987-01-01

Reactivity of halide and pseudohalide (cyanide, azide, thiocyanate, cyanate) ligands tending to form bridge bonds in transition metal (Re, Mo, W) complexes is considered. Complexes where transition metal salts are ligands of other, complex-forming ion, are described. Transformation of innerspheric pseudohalide ligands is an important way of directed synthesis of these metal coordination compounds

Transcriptional and physiological changes during Mycobacterium tuberculosis reactivation from non-replicating persistence

Directory of Open Access Journals (Sweden)

Peicheng Du

2016-08-01

Full Text Available Mycobacterium tuberculosis can persist for years in the hostile environment of the host in a non-replicating or slowly replicating state. While active disease predominantly results from reactivation of a latent infection, the molecular mechanisms of M. tuberculosis reactivation are still poorly understood. We characterized the physiology and global transcriptomic profiles of M. tuberculosis during reactivation from hypoxia-induced non-replicating persistence. We found that M. tuberculosis reactivation upon reaeration was associated with a lag phase, in which the recovery of cellular physiological and metabolic functions preceded the resumption of cell replication. Enrichment analysis of the transcriptomic dynamics revealed changes to many metabolic pathways and transcription regulons/subnetworks that orchestrated the metabolic and physiological transformation in preparation for cell division. In particular, we found that M. tuberculosis reaeration lag phase is associated with down-regulation of persistence-associated regulons/subnetworks, including DosR, MprA, SigH, SigE and ClgR, as well as metabolic pathways including those involved in the uptake of lipids and their catabolism. More importantly, we identified a number of up-regulated transcription regulons and metabolic pathways, including those involved in metal transport and remobilization, second messenger-mediated responses, DNA repair and recombination, and synthesis of major cell wall components. We also found that inactivation of the major alternative sigma factors SigE or SigH disrupted exit from persistence, underscoring the importance of the global transcriptional reprogramming during M. tuberculosis reactivation. Our observations suggest that M. tuberculosis lag phase is associated with a global gene expression reprogramming that defines the initiation of a reactivation process.

Synthesis of Zinc Diethyldithiocarbamate (ZDEC) and Structure Characterization using Decoupling 1H NMR

International Nuclear Information System (INIS)

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

Design, synthesis, and characterization of novel fine-particle, unsupported catalysts for coal liquefaction

Energy Technology Data Exchange (ETDEWEB)

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.

Synthesis and characterization of a cerebral radiotracer

International Nuclear Information System (INIS)

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.

Microstructure and wear resistance of Al2O3-M7C3/Fe composite coatings produced by laser controlled reactive synthesis

Science.gov (United States)

Tan, Hui; Luo, Zhen; Li, Yang; Yan, Fuyu; Duan, Rui

2015-05-01

Based on the principle of thermite reaction of Al and Fe2O3 powders, the Al2O3 ceramic reinforced Fe-based composite coatings were fabricated on a steel substrate by laser controlled reactive synthesis and cladding. The effects of different additions of thermite reactants on the phase transition, microstructure evolution, microhardness and wear resistance of the composite coatings were investigated by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Vickers microhardness and block-on-ring wear test, respectively. The results show that Al2O3 ceramic and M7C3 carbide are in situ synthesized via the laser controlled reactive synthesis. The Al2O3 ceramic and M7C3 carbides prefer to distribute along the γ-Fe phase boundary continuously, which separates the γ-Fe matrix and is beneficial to the grain refinement. With the increase of thermite reactants, the amount of Al2O3 ceramic and M7C3 carbide in the composite coatings increases gradually. Moreover the cladding layer changes from dendritic structure to columnar structure and martensite structure in the heat affected zone becomes coarse. The increased thermite reactants improve the microhardness and wear resistance of the in situ composite coatings obviously and enhance the hardness of the heat affected zone, which should be ascribed to the grain refinement, ceramic and carbide precipitation and solid solution strengthening.

PAMAM dendrimer-coated iron oxide nanoparticles: synthesis and characterization of different generations

International Nuclear Information System (INIS)

Khodadust, Rouhollah; Unsoy, Gozde; Yalcın, Serap; Gunduz, Gungor; Gunduz, Ufuk

2013-01-01

This study focuses on the synthesis and characterization of different generations (G 0 –G 7 ) of polyamidoamine (PAMAM) dendrimer-coated magnetic nanoparticles (DcMNPs). In this study, superparamagnetic iron oxide nanoparticles were synthesized by co-precipitation method. The synthesized nanoparticles were modified with aminopropyltrimethoxysilane for dendrimer coating. Aminosilane-modified MNPs were coated with PAMAM dendrimer. The characterization of synthesized nanoparticles was performed by X-ray diffraction, X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), dynamic light scattering, and vibrating sample magnetometry (VSM) analyses. TEM images demonstrated that the DcMNPs have monodisperse size distribution with an average particle diameter of 16 ± 5 nm. DcMNPs were found to be superparamagnetic through VSM analysis. The synthesis, aminosilane modification, and dendrimer coating of iron oxide nanoparticles were validated by FTIR and XPS analyses. Cellular internalization of nanoparticles was studied by inverted light scattering microscopy, and cytotoxicity was determined by XTT analysis. Results demonstrated that the synthesized DcMNPs, with their functional groups, symmetry perfection, size distribution, improved magnetic properties, and nontoxic characteristics could be suitable nanocarriers for targeted cancer therapy upon loading with various anticancer agents.

Synthesis and Characterization of Nano Scale YBCO

International Nuclear Information System (INIS)

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)

Synthesis and characterization of ruthenium-decorated nanoporous platinum materials

International Nuclear Information System (INIS)

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

Synthesis and characterization of cobalt sulfide nanoparticles by sonochemical method

Science.gov (United States)

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.

Synthesis and Physicochemical Characterization of Mesoporous SiO2 Nanoparticles

Directory of Open Access Journals (Sweden)

Dharani Das

2014-01-01

Full Text Available There exists a knowledge gap in understanding potential toxicity of mesoporous silica nanoparticles. A critical step in assessing toxicity of these particles is to have a wide size range with different chemistries and physicochemical properties. There are several challenges when synthesizing mesoporous silica nanoparticles over a wide range of sizes including (1 nonuniform synthesis protocols using the same starting materials, (2 the low material yield in a single batch synthesis (especially for particles below 60–70 nm, and (3 morphological instability during surfactant removal process and surface modifications. In this study, we synthesized a library of mesoporous silica nanoparticles with approximate particle sizes of 25, 70, 100, 170, and 600 nm. Surfaces of the silica nanoparticles were modified with hydrophilic-CH2–(CH22–COOH and relatively hydrophobic-CH2–(CH210–COOH functional groups. All silica nanoparticles were analysed for morphology, surface functionality, surface area/pore volume, surface organic content, and dispersion characteristics in liquid media. Our analysis revealed the synthesis of a spectrum of monodisperse bare and surface modified mesoporous silica nanoparticles with a narrow particle size distribution and devoid of cocontaminants critical for toxicity studies. Complete physicochemical characterization of these synthetic mesoporous silica nanoparticles will permit systematic toxicology studies for investigation of structure-activity relationships.

Eco-friendly green synthesis of silver nanoparticles using salmalia malabarica: synthesis, characterization, antimicrobial, and catalytic activity studies

Science.gov (United States)

Murali Krishna, I.; Bhagavanth Reddy, G.; Veerabhadram, G.; Madhusudhan, A.

2016-06-01

An economically viable and "green" process has been developed for the synthesis of silver nanoparticles (AgNPs) with an average size of 7 nm using non-toxic and renewable salmalia malabarica gum (SMG) as reducing and capping agent without using any chemical reducing agent. The effect of various parameters such as concentration of SMG and silver nitrate and reaction time for the synthesis of AgNPs was studied. The synthesized AgNPs are systematically characterized by UV/Vis spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction and Transmission electron microscopy. The resultant SMG-capped AgNPs are highly stable and had significant antibacterial action on both Escherichia coli ( E. coli) and Staphylococcus aureus ( S. aureus). The catalytic action of the SMG-capped AgNPs to initiate the reduction of 4-nitrophenol (4-NP) in the presence of NaBH4 has also been reported. The kinetics of the reaction was found to be of pseudo-first-order with respect to the 4-NP.

Synthesis and Characterization of C-Cinnamal Calix [4] Resorsinarena from Cinnamon Oil Waste West Sumatra

Science.gov (United States)

Etika, S. B.; Nasra, E.; Rilaztika, I.

2018-04-01

Synthesis and characterization of compound C-Cinnamal Calix [4] Resorsinarena (CCCR) of cinnamon oil waste have been done. This study was aimed to synthesis and characterize C-Cinnamal Calix [4] Resorsinarena from cinnamaldehyde violated cinnamon oil waste. C-Cinnamal Calix [4] Resorsinarena was synthesized by electrophilic substitution reaction of cinnamaldehyde isolated by the acid and resorcinol at 77oC temperature for 2 hour. The data analysis spectrum UV-VIS and FT-IR showed that the compound isolated cinnamaldehyde same as pure cinnamaldehyde compound. The characterization of C-Cinnamal Calix [4] Resorsinarena in the form of reddish-colored solids with melting point 3580C by using UV-VIS showed the presence of double bond, FT-IR showed the absorption at the wave number 3323,94 cm-1 indicating the ‑OH group, the wave number 1610,94 cm-1 showed the vibration C=C, the strong region absorption of 1500,86 cm-1 indicating the presence of an aromatic ring, the at 1442,88 cm-1 wave number indicating the presence of CH3.

Synthesis and characterization of nanocomposites ZnO / polypyrrole for anti corrosive application

International Nuclear Information System (INIS)

Valenca, D.P.; Bouchonneau, N.; Vieira, M.R.S.; Alves, K.G.B.; Melo, C.P. de; Urtiga Filho, S.L.

2014-01-01

Nanoparticles of metal oxides and conductive polymers have been investigated as alternative additives in corrosion protection of oxidizable metals. In this hybrid nanocomposites work Polypyrrole-ZnO were synthesized and characterized as a potential application as industrial paint anti corrosive additive. The different steps of the synthesis and characterization of nanocomposites are described. The nanocomposites were obtained from the emulsion polymerization of aqueous solutions of pyrrole and sodium dodecyl sulfate containing ZnO nanoparticles dispersed in the mass. The nanoparticles were characterized by scanning electron microscopy and transmission, dynamic light scattering, diffraction of X-rays and techniques of infrared spectroscopy. From the characterization techniques, it was possible to determine the average size of nanoparticles of ZnO and ZnO-Polypyrrole. The peaks in the diffraction pattern of X-rays observed in the nanocomposite were the same as in ZnO, confirming the presence of ZnO in the composite. (author)

Synthesis, Characterization, and Ultrafast Dynamics of Metal, Metal Oxide, and Semiconductor Nanomaterials

OpenAIRE

Wheeler, Damon Andreas

2013-01-01

SYNTHESIS, CHARACTERIZATION, AND ULTRAFAST DYNAMICS OF METAL, METAL OXIDE, AND SEMICONDUCTOR NANOMATERIALSABSTRACTThe optical properties of each of the three main classes of inorganic nanomaterials, metals, metal oxides, and semiconductors differ greatly due to the intrinsically different nature of the materials. These optical properties are among the most fascinating and useful aspects of nanomaterials with applications spanning cancer treatment, sensors, lasers, and solar cells. One techn...

Self-Assembled Structures of PMAA-PMMA Block Copolymers : Synthesis, Characterization, and Self-Consistent Field Computations

NARCIS (Netherlands)

Li, Feng; Schellekens, Mike; de Bont, Jens; Peters, Ron; Overbeek, Ad; Leermakers, Frans A. M.; Tuinier, Remco

2015-01-01

Block copolymers composed of methacrylic acid (MAA) and methyl methacrylate (MMA) blocks are interesting candidates for replacing surfactants in emulsion polymerization methods. Here the synthesis and experimental characterization of well-defined PMAA-PMMA block copolymers made via RAFT

Self-assembled structures of PMAA-PMMA block copolymers: Synthesis, characterization, and self-consistent field computations

NARCIS (Netherlands)

Li, F.; Schellekens, J.; Bont, de J.A.M.; Peters, R.; Overbeek, A.; Leermakers, F.A.M.; Tuinier, R.

2015-01-01

Block copolymers composed of methacrylic acid (MAA) and methyl methacrylate (MMA) blocks are interesting candidates for replacing surfactants in emulsion polymerization methods. Here the synthesis and experimental characterization of well-defined PMAA–PMMA block copolymers made via RAFT

Synthesis, characterization and optimization of poly(p-phenylenediamine)-based organoclay composite for Cr(VI) remediation

CSIR Research Space (South Africa)

Mdlalose, L

2017-04-01

Full Text Available of these materials for environmental remediation. We report here the synthesis, characterization and application of a poly(para-phenylenediamine) (poly-pPD) organoclay-based composite for removal of Cr(VI) complexes from wastewater. Adsorption capacity...

Synthesis and characterization of related substances of Azilsartan Kamedoxomil

Directory of Open Access Journals (Sweden)

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.

Green Synthesis and Characterizations of Flower Shaped CuO Nanoparticles for Biodiesel Application

Directory of Open Access Journals (Sweden)

Rintu Varghese

2017-03-01

Full Text Available Nanomaterials are primary candidates to play a key role in energy future. In this work, plant-mediated green synthesis of CuO nanoparticles was studied. The CuO nanoparticles were used as the catalysts for the production of biodiesel from coconut oil. An aqueous extract of Centella Asiatica leaves was used as a bio-reducing agent for the synthesis of CuO nanoparticles. This biocatalyst was characterized by using different techniques (FTIR, UV-Vis spectroscopy, XRD, FESEM with EDX which were confirmed the formation of CuO nanoparticles. Further, the presences of FAME (Fatty Acid Methyl Ester groups at the produced biodiesel were confirmed using both the GC-MS and FTIR analysis. From this work, it has been concluded that the plant extract mediated synthesis of CuO nanoparticles is quite simple, cost-effective and environmentally friendly. The produced biodiesel from coconut oil is considered to be a potential source for alternative conventional fuel.

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

Science.gov (United States)

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.

Synthesis and characterization of "1"3C_3-tristearin

International Nuclear Information System (INIS)

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)

A facile soft template synthesis and characterization of PbHAsO4 nanocrystals

International Nuclear Information System (INIS)

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

Iodine-catalyzed diazo activation to access radical reactivity.

Science.gov (United States)

Li, Pan; Zhao, Jingjing; Shi, Lijun; Wang, Jin; Shi, Xiaodong; Li, Fuwei

2018-05-17

Transition-metal-catalyzed diazo activation is a classical way to generate metal carbene, which are valuable intermediates in synthetic organic chemistry. An alternative iodine-catalyzed diazo activation is disclosed herein under either photo-initiated or thermal-initiated conditions, which represents an approach to enable carbene radical reactivity. This metal-free diazo activation strategy were successfully applied into olefin cyclopropanation and epoxidation, and applying this method to pyrrole synthesis under thermal-initiated conditions further demonstrates the unique reactivity using this method over typical metal-catalyzed conditions.

Prediction of the Chapman-Jouguet chemical equilibrium state in a detonation wave from first principles based reactive molecular dynamics.

Science.gov (United States)

Guo, Dezhou; Zybin, Sergey V; An, Qi; Goddard, William A; Huang, Fenglei

2016-01-21

The combustion or detonation of reacting materials at high temperature and pressure can be characterized by the Chapman-Jouguet (CJ) state that describes the chemical equilibrium of the products at the end of the reaction zone of the detonation wave for sustained detonation. This provides the critical properties and product kinetics for input to macroscale continuum simulations of energetic materials. We propose the ReaxFF Reactive Dynamics to CJ point protocol (Rx2CJ) for predicting the CJ state parameters, providing the means to predict the performance of new materials prior to synthesis and characterization, allowing the simulation based design to be done in silico. Our Rx2CJ method is based on atomistic reactive molecular dynamics (RMD) using the QM-derived ReaxFF force field. We validate this method here by predicting the CJ point and detonation products for three typical energetic materials. We find good agreement between the predicted and experimental detonation velocities, indicating that this method can reliably predict the CJ state using modest levels of computation.

Synthesis and Characterization of Hydroxyapatite/Fullerenol Nanocomposites.

Science.gov (United States)

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.

[Changes of vascular reactivity and reactive oxygen species in conditions of varying duration of permanent stay in the alienation zone in mice].

Science.gov (United States)

Tkachenko, M M; Kotsiuruba, A V; Baziliuk, O V; Horot', I V; Sahach, V F

2010-01-01

Peculiarities of changes in the vascular reactivity and in the content of reactive forms of oxygen and stable metabolites of nitric oxide (NO) were studied in the aorta preparations of C57BL/6 and BALB/c mice of the two age groups (6 and 18 mo.), which were born and permanently kept in the Chernobyl alienation zone. The results obtained showed a disturbance of acetylcholine-induced endothelium-dependent reactions of relaxation of smooth muscles of the thoracic aorta. A lower level of NO synthesis and lower level of oxidative arginase metabolism of arginine corresponded to a higher degree of damage of endothelium-dependent reactions of relaxation of the thoracic aorta smooth muscles. A decrease of NO synthesis in conditions of permanent effects of low doses of radiation was conditioned by an increase of generation of reactive forms of oxygen, namely, superoxide and hydroxyl radicals, which might be formed in mitochondria. In conditions of permanent effects of low doses of radiation a lesser level of protein nitrosothilation, same as lesser one of generation of OH-radical, corresponded to a higher level of damage of endothelium-dependent reactions.

Synthesis, Characterization and Applications of One-Dimensional Metal Oxide Nanostructures

Science.gov (United States)

Santulli, Alexander

Nanomaterials have been of keen research interest, owing to their exciting and unique properties (e.g. optical, magnetic, electronic, and mechanical). These properties allow nanomaterials to have many applications in areas of medicine, alternative energy, catalysis, and information storage. In particular, one-dimensional (1D) nanomaterials are highly advantageous, owing to the inherent anisotropic nature, which allows for effective transport and study of properties on the nanoscale. More specifically, 1D metal oxide nanomaterials are of particular interest, owing to their high thermal and chemical stability, as well as their intriguing optical, electronic, and magnetic properties. Herein, we will investigate the synthesis and characterization of vanadium oxide, lithium niobate and chromium oxide. We will explore the methodologies utilized for the synthesis of these materials, as well as the overall properties of these unique nanomaterials. Furthermore, we will explore the application of titanium dioxide nanomaterials as the electron transport layer in dye sensitized solar cells (DSSCs), with an emphasis on the effect of the nanoscale morphology on the overall device efficiency.

β-galactosidase-catalyzed synthesis of galactosyl chlorphenesin and its characterization.

Science.gov (United States)

Lee, Sang-Eun; Jo, Tae-Min; Lee, Hyang-Yeol; Lee, Jongsung; Jung, Kyung-Hwan

2013-11-01

We synthesized galactosyl chlorphenesin (CPN-G) using β-gal-containing Escherichia coli (E. coli) cells in which the conversion yield of chlorphenesin (CPN) to CPN-G reached about 64 % during 12 h. CPN-G was identified and characterized using high-performance liquid chromatography, liquid chromatography-mass spectrometry, Fourier transform-infrared spectrometry, and nuclear magnetic resonance analysis ((1)H and (13)C). We verified that a galactose was covalently bound to a CPN alcohol group during CPN-G synthesis throughout these analyses. In particular, by the hydrolysis of CPN-G using β-gal, it was confirmed that a galactose was bound to CPN. The minimal inhibitory concentration (MIC) results showed that the CPN-G MICs were fairly similar to those of CPN. HACAT cell viability was significantly higher in CPN-G-treated cells than in CPN-treated cells at concentrations of 0.0-20.0 mM. Finally, we accomplished the synthesis of less toxic CPN-G, compared with CPN, using β-gal-containing E. coli cells as whole cells without changes in the MICs against microorganisms.

SYNTHESIS, CHARACTERIZATION AND ANTIBACTERIAL ...

African Journals Online (AJOL)

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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), ...

Surface Reactivity of Li2MnO3: First-Principles and Experimental Study.

Science.gov (United States)

Quesne-Turin, Ambroise; Flahaut, Delphine; Croguennec, Laurence; Vallverdu, Germain; Allouche, Joachim; Charles-Blin, Youn; Chotard, Jean-Noël; Ménétrier, Michel; Baraille, Isabelle

2017-12-20

This article deals with the surface reactivity of (001)-oriented Li 2 MnO 3 crystals investigated from a multitechnique approach combining material synthesis, X-ray photoemission spectroscopy (XPS), scanning electron microscopy, Auger electron spectroscopy, and first-principles calculations. Li 2 MnO 3 is considered as a model compound suitable to go further in the understanding of the role of tetravalent manganese atoms in the surface reactivity of layered lithium oxides. The knowledge of the surface properties of such materials is essential to understand the mechanisms involved in parasitic phenomena responsible for early aging or poor storage performances of lithium-ion batteries. The surface reactivity was probed through the adsorption of SO 2 gas molecules on large Li 2 MnO 3 crystals to be able to focus the XPS beam on the top of the (001) surface. A chemical mapping and XPS characterization of the material before and after SO 2 adsorption show in particular that the adsorption is homogeneous at the micro- and nanoscale and involves Mn reduction, whereas first-principles calculations on a slab model of the surface allow us to conclude that the most energetically favorable species formed is a sulfate with charge transfer implying reduction of Mn.

Synthesis, purification and physico-chemical characterization of the deuterized chloroform

International Nuclear Information System (INIS)

Mihaila, V.; Olteanu-Chiper, D.

1999-01-01

This work refers to deuterized chloroform synthesis and purification methods. Three methods for obtaining deuterized chloroform are presented. 1. The direct chlorination of methane, in presence of light and in oxygen-free atmosphere: CH 4 + 3 Cl 2 + ℎν→ CHCl 3 + 3 HCl. The method's drawback is that the product obtained is impure, as other chlorinated compounds such as CH 3 Cl, CH 2 Cl 2 , CCl 4 also result. 2. Chlorination of acetaldehyde or acetone, in basic catalysis and in halogen excess (α substitution with direct synthesis of trihalogen compound), followed by a haloform reaction (hydrolytic splitting) in presence of chlorinated lime: CH 3 CHO (Cl 2 /HO - )/(-HCl)Cl 3 C-CHO (CaCl 2 /HOH)/(-(HCOO) 2 Ca) CHCl 3 and CH 3 -CO-CH 3 (Cl 2 /HO)/(-HCl) Cl 3 C-CO-CH 3 (NaOH)/(-CH 3 COONa) CHCl 3 . 3. Decarboxylizing of trichloroacetate acid (as sodium salt): Cl 3 C-COONa (t deg C)/(H 2 O) Cl 3 CH + NaHCO 3 . This method is the most suitable for the deuterized chloroform synthesis since the reaction takes place in absence of other hydrogen atoms (protons) and in deuterized water 99,87% purity, according to the following reaction: Cl 3 C-COONa (t deg C)/(D 2 O) Cl 3 CD + NaDCO 3 . Another advantage is that this method avoids the synthesis of secondary products which could entail additional purifications (distillations, rectifications, a.s.o.). The deuterized chloroform is separated from the deuterized sodium bicarbonate aqueous solution by washing with deuterized water, in a liquid-to-liquid separating funnel. After separation, the deuterized chloroform is dried in nitrogen atmosphere. The characterization of the final product is carried out through Nuclear Magnetic Resonance Spectrometry. (authors)

Synthesis and characterization of homogeneous interstitial solutions of nitrogen and carbon in iron-based lattices

DEFF Research Database (Denmark)

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...

Linking new information to a reactivated memory requires consolidation and not reconsolidation mechanisms.

Directory of Open Access Journals (Sweden)

2005-09-01

Full Text Available A new memory is initially labile and becomes stabilized through a process of consolidation, which depends on gene expression. Stable memories, however, can again become labile if reactivated by recall and require another phase of protein synthesis in order to be maintained. This process is known as reconsolidation. The functional significance of the labile phase of reconsolidation is unknown; one hypothesis proposes that it is required to link new information with reactivated memories. Reconsolidation is distinct from the initial consolidation, and one distinction is that the requirement for specific proteins or general protein synthesis during the two processes occurs in different brain areas. Here, we identified an anatomically distinctive molecular requirement that doubly dissociates consolidation from reconsolidation of an inhibitory avoidance memory. We then used this requirement to investigate whether reconsolidation and consolidation are involved in linking new information with reactivated memories. In contrast to what the hypothesis predicted, we found that reconsolidation does not contribute to the formation of an association between new and reactivated information. Instead, it recruits mechanisms similar to those underlying consolidation of a new memory. Thus, linking new information to a reactivated memory is mediated by consolidation and not reconsolidation mechanisms.

Refined Synthesis and Characterization of Controlled Diameter, Narrow Size Distribution Microparticles for Aerospace Research Applications

Science.gov (United States)

Tiemsin, Pacita I.; Wohl, Christopher J.

2012-01-01

Flow visualization using polystyrene microspheres (PSL)s has enabled researchers to learn a tremendous amount of information via particle based diagnostic techniques. To better accommodate wind tunnel researchers needs, PSL synthesis via dispersion polymerization has been carried out at NASA Langley Research Center since the late 1980s. When utilizing seed material for flow visualization, size and size distribution are of paramount importance. Therefore, the work described here focused on further refinement of PSL synthesis and characterization. Through controlled variation of synthetic conditions (chemical concentrations, solution stirring speed, temperature, etc.) a robust, controllable procedure was developed. The relationship between particle size and salt concentration, MgSO4, was identified enabling the determination of PSL diameters a priori. Suggestions of future topics related to PSL synthesis, stability, and size variation are also described.

Synthesis and characterization of Al-TON zeolite using a dialkylimizadolium as structure-directing agent

Energy Technology Data Exchange (ETDEWEB)

Lopes, Christian Wittee; Pergher, Sibele Berenice Castella, E-mail: chriswittee@gmail.com [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil); Villarroel-Rocha, Jhonny [Laboratorio de Solidos Porosos, Instituto de Fisica Aplicada, Universidad Nacional de San Luis, Chacabuco, San Luis (Argentina); Silva, Bernardo Araldi Da; Mignoni, Marcelo Luis [Universidade Regional Integrada, Erechim, RS (Brazil)

2016-11-15

In this work, the synthesis of zeolites using 1-butyl-3-methylimidazolium chloride [C{sub 4}MI]Cl as a structure-directing agent was investigated. The organic cation shows effectiveness and selectivity for the syntheses of TON zeolites under different reaction conditions compared to the traditional structure directing agent, 1,8-diaminooctane. The 1-butyl-3-methylimidazolium cation lead to highly crystalline materials and its role as OSDA in our synthesis conditions has been confirmed by characterization techniques. ICP-OES confirms the presence of Al in the samples and {sup 27}Al MAS NMR analysis indicated that aluminum atoms were incorporated in tetrahedral coordination. Scanning electron microscopy indicated that changing the crystallization condition (static or stirring), zeolites with different crystal size were obtained, which consequently affects the textural properties of the zeolites. Moreover, varying some synthesis parameters MFI zeolite can also be obtained. (author)

Antibacterial gold nanoparticles-biomass assisted synthesis and characterization.

Science.gov (United States)

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.

Synthesis and characterization of waterborne polyurethane acrylate copolymers

International Nuclear Information System (INIS)

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

Synthesis, characterization and behaviour to gamma radiation of the bis-L-alaninato-copper (II)

International Nuclear Information System (INIS)

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.)

Synthesis and characterization of low-valence actinide phosphide tellurides and ternary selenium-halide iridium complexes; Synthese und Charakterisierung niedervalenter Actinoidphosphidtelluride und ternaerer Selen-Halogenid-Komplexe des Iridiums

Energy Technology Data Exchange (ETDEWEB)

Stolze, Karoline

2016-04-07

The thesis on the synthesis and characterization of low-valence actinide phosphide tellurides and ternary selenium-halide iridium complexes includes two parts: a description of the experimental synthesis of UPTe and U2PTe2O and ThPTe and the synthesis of selenium-chloride iridium complexes and selenium-bromide iridium complexes. The characterization included X-ray diffraction and phase studies.

Synthesis and characterization of KY3F10 and KY3F10:Yb:Nd:Tm crystals for optical applications

International Nuclear Information System (INIS)

Linhares, Horacio Marconi da Silva Dantas

2009-01-01

In this work, crystals of KY 3 F 10 pure and doped with Yb, Nd and Tm were grown aiming at the attainment of blue emission via Tm 3+ ions up conversion. It was established the best conditions to synthesis and purification of KY 3 F 10 . Crystals doped with 1.3 mol% Nd, 0.5 mol% Tm and some concentrations of Yb (5, 10, 20, 30 and 40 mol%) were obtained by slow cooling of the charge from the melt, using an usual conventional synthesis system and in a reactive HF atmosphere. It was taken into account parameters as cooling rate and different configurations of boats to conditioning the materials. The limit of Yb concentration to obtain a unique cubic phase was determined as 30mol%, for the cooling rates used in this work. The physical and chemical characterizations of the samples were performed by X-ray diffraction, differential thermal analysis, inductively coupled plasma-optical emission spectroscopy (ICP-OES), scanning electron microscopy, optical absorption and emission. An initial spectroscopic study was performed to verify the effect of the Yb 3+ concentration regarding the blue emission efficiency in the KY 3 F 10 :Yb:Nd:Tm. When the Nd 3+ is pumped at 797 nm, it was determined that the suitable Yb concentrations are between 10 and 20 mol% to obtain blue emission at 480 nm, and between 20 and 30 mol% to obtain emission at 450 nm. It was observed that two emissions bands in the UV (350 and 360nm) enhanced proportionally with the Yb 3+ concentration. (author)

Synthesis and characterization of carboxylic acid functionalized silicon nanoparticles

Science.gov (United States)

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

Synthesis and Characterization of EDTA Complexes Useful for Trace Elements Supplementation

Directory of Open Access Journals (Sweden)

Baran Enrique J.

2002-01-01

Full Text Available The synthesis of two heterobimetallic EDTA complexes, MgCu(EDTA.6H2O and ZnCu(EDTA.6H2O, is described. They were characterized by means of vibrational (infrared and Raman and electronic (reflectance spectroscopy. Several dissolution tests in 0.1 N HCl and simulated gastric juice were also performed. The results support the potential usefulness of these complexes for copper supplementation in human and veterinary medicine and to the simultaneous reinforcement of Mg(II and Zn(II levels.

Chevrel phases superconductive and ultrafine powders synthesis and characterization; Synthese et caracterisation de poudres ultrafines supraconductrices de phases de Chevrel

Energy Technology Data Exchange (ETDEWEB)

Even-Boudjada, S

1994-12-01

This work deals with the Chevrel phases superconductive and ultrafine powders synthesis and characterization. The first part of this study presents some new way of synthesis (precipitation, coprecipitation) of Chevrel phases precursors powders (PbS, SnS, MoS{sub 2}) and their characterizations (X-ray fluorescence analysis, ICP mass spectroscopy, scanning electron microscopy, transmission electron microscopy and laser granulometry). These new synthesis methods lead to quasi spherical morphology grains and very weak size grains (0.2 to 0.5 {mu}m) whereas the chemical preparation from the solid state elements gives very different morphology grains (small plates) with a size of 1 to 20 {mu}m. In the second part is shown the interest of the binary Mo{sub 6} S{sub 8} as precursor in the synthesis of ternary superconductive phases (Li, Ni, Cu, Pb). The last part presents the formation reaction of the phase PbMo{sub 6} S{sub 8} and its main chemical and physical properties. Thus some calorimetric measures associated with X-ray diffraction analysis have been realized and have allowed to understand the different reactions occurring during the PbMo{sub 6}S{sub 8} synthesis. (O.L.). 100 refs., figs., tabs.

On-Surface Synthesis and Characterization of Honeycombene Oligophenylene Macrocycles.

Science.gov (United States)

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.

Design, synthesis, and characterization of 0-D, 1-D, and 2-D Zinc–Adeninate coordination assemblies

Energy Technology Data Exchange (ETDEWEB)

An, Ji Hyun [Dept. of Chemistry Education, Seoul National University, Seoul (Korea, Republic of); Geib, Steven J. [Dept. of Chemistry, University of Pittsburgh, Pittsburgh (United States); Kim, Myung Gil [Dept. of Chemistry, Chungang University, Seoul (Korea, Republic of)

2015-08-15

In this study, we demonstrate the synthesis and characterization of zinc– adeninate coordination polymers with 0-D, 1-D, and 2-D structures. We describe methods for controlling the structure of these materials by applying different synthetic conditions and discuss their structural relationships. 0-D, 1-D, and 2-D zinc–adeninate coordination polymers with the same metal–adeninate coordination mode were synthesized and characterized. By controlling the temperature, a material with 0-D macrocycle or 1-D chain coordination polymer was prepared. A replacement of pyridine with bipyridine formed 2-D sheet structure by connecting 1-D chains with each other. They exhibited an interesting relationship between synthetic methods and structures. Further study of metal–adeninate coordination chemistry will render a precise control of the structure in synthesis and will open a new venue to new materials with fascinating properties.

Graphitic carbon nitride: Synthesis, characterization and photocatalytic decomposition of nitrous oxide

International Nuclear Information System (INIS)

Praus, Petr; Svoboda, Ladislav; Ritz, Michal; Troppová, Ivana; Šihor, Marcel; Kočí, Kamila

2017-01-01

Graphitic carbon nitride (g-C_3N_4) was synthetized by condensation of melamine at the temperatures of 400–700 °C in air for 2 h and resulting products were characterized and finally tested for the photocatalytic decomposition of nitrous oxide. The characterization methods were elemental analysis, UV–Vis diffuse reflectance spectroscopy (DRS), photoluminescence (PL), Fourier transform infrared (FTIR) and Raman spectroscopy, measurement of specific surface area (SSA), X-ray powder diffraction (XRD), scanning (SEM) and transmission (TEM) electron microscopy. The XRD patterns, FTIR and Raman spectra proved the presence of g-C_3N_4 at above 550 °C but the optimal synthesis temperature of 600–650 °C was found. Under these conditions graphitic carbon nitride of the overall empirical composition of C_6N_9H_2 was formed. At lower temperatures g-C_3N_4 with a higher content of hydrogen was formed but at higher temperatures g-C_3N_4 was decomposed. At the temperatures above 650 °C, its exfoliation was observed. The photocatalytic experiments showed that the activity of all the samples synthetized at 400–700 °C was very similar, that is, within the range of experimental error (5 %). The total conversion of N_2O reached about 43 % after 14 h. - Highlights: • Graphitic carbon nitride (g-C_3N_4) was thermally synthetized from melamine in the range of 400–700 °C. • The optimal temperature was determined at 600–650 °C. • All synthesis products were properly characterized by physico-chemical methods. • Exfoliation of g-C_3N_4 at above 600 °C was observed. • g-C_3N_4 was used for the photocatalytic decomposition of N_2O.

Characterization of PDMS samples with variation of its synthesis parameters for tunable optics applications

Science.gov (United States)

Marquez-Garcia, Josimar; Cruz-Félix, Angel S.; Santiago-Alvarado, Agustin; González-García, Jorge

2017-09-01

Nowadays the elastomer known as polydimethylsiloxane (PDMS, Sylgard 184), due to its physical properties, low cost and easy handle, have become a frequently used material for the elaboration of optical components such as: variable focal length liquid lenses, optical waveguides, solid elastic lenses, etc. In recent years, we have been working in the characterization of this material for applications in visual sciences; in this work, we describe the elaboration of PDMSmade samples, also, we present physical and optical properties of the samples by varying its synthesis parameters such as base: curing agent ratio, and both, curing time and temperature. In the case of mechanical properties, tensile and compression tests were carried out through a universal testing machine to obtain the respective stress-strain curves, and to obtain information regarding its optical properties, UV-vis spectroscopy is applied to the samples to obtain transmittance and absorbance curves. Index of refraction variation was obtained through an Abbe refractometer. Results from the characterization will determine the proper synthesis parameters for the elaboration of tunable refractive surfaces for potential applications in robotics.

Synthesis and characterization of the Cu2ZnSnS4 system for photovoltaic applications

Science.gov (United States)

Sánchez Pinzón, D. L.; Soracá Perez, G. Y.; Gómez Cuaspud, J. A.; López, E. Vera

2017-01-01

This paper focuses on the synthesis and characterization of a ceramic material based on the Cu2ZnSnS4 system, through the implementation of a hydrothermal route. For this purpose, we started from nitrate dissolutions in a 1.0mol L-1 concentration, which were mixed and treated in a teflon lined vessel steel at 280°C for 48h. The Physicochemical characterization of the solid was evaluated by means of ultraviolet visible spectroscopy (UV-VIS), X-ray diffraction (XRD), Raman spectroscopy, scanning and transmission electron microscopy (SEM-TEM) and solid state impedance spectroscopy (IS). The initial characterization through UV measurements confirms a Band-gap around 1.46eV obtained by the Kubelka-Munk method, which demonstrates the effectiveness of the synthesis method in the obtaining of a semiconductor material. The XRD results confirm the obtaining of a crystalline material of pure phase with tetragonal geometry and I-42m space group. The preferential crystalline orientation was achieved along (2 2 0) facet, with crystallite sizes of nanometric order (6.0nm). The morphological aspects evaluated by means electron microscopy, confirmed the homogeneity of the material, showing specifically a series of textural and surface properties of relevant importance. Finally, the electrical characterizations allow to validate the semiconductor behaviour of CZTS system for development of photovoltaic technologies.

Synthesis and characterization of reactions by nanoferrites Co2Fe2O4 combustion

International Nuclear Information System (INIS)

Santos, P.T.A.; Dantas, B.B.; Costa, A.C.F.M.; Araujo, P.M.A.G.

2012-01-01

In this work CoFe 2 O 4 of magnetic nanoparticles were synthesized by combustion reaction and the structural and morphological characteristics of the synthesized samples as well as the parameters of synthesis temperature and reaction time were investigated in order to assess the reproducibility of the synthesis. The maximum temperature and time of the combustion flame were obtained with pyrometer coupled to a computer with online measurement and a stopwatch. The resulting samples were characterized by X-ray diffraction (XRD), infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The maximum temperature achieved during synthesis for all reactions ranged from 623 deg C and 755 deg C. The combustion flame time varied between 18 and 23 seconds. The XRD showed the formation of only CoFe 2 O 4 inverse spinel phase, with crystallite size 28 nm and crystallinity 78%, with typical morphology of the formation of agglomerates of uniform size, brittle and comprising nanoparticles together by weak forces. (author)

Synthesis and Characterization of Stimuli Responsive Block Copolymers, Self-Assembly Behavior and Applications

Energy Technology Data Exchange (ETDEWEB)

Determan, Michael Duane [Iowa State Univ., Ames, IA (United States)

2005-12-17

The central theme of this thesis work is to develop new block copolymer materials for biomedical applications. While there are many reports of stimuli-responsive amphiphilic [19-21] and crosslinked hydrogel materials [22], the development of an in situ gel forming, pH responsive pentablock copolymer is a novel contribution to the field, Figure 1.1 is a sketch of an ABCBA pentablock copolymer. The A blocks are cationic tertiary amine methacrylates blocked to a central Pluronic F127 triblock copolymer. In addition to the prerequisite synthetic and macromolecular characterization of these new materials, the self-assembled supramolecular structures formed by the pentablock were experimentally evaluated. This synthesis and characterization process serves to elucidate the important structure property relationships of these novel materials, The pH and temperature responsive behavior of the pentablock copolymer were explored especially with consideration towards injectable drug delivery applications. Future synthesis work will focus on enhancing and tuning the cell specific targeting of DNA/pentablock copolymer polyplexes. The specific goals of this research are: (1) Develop a synthetic route for gel forming pentablock block copolymers with pH and temperature sensitive properties. Synthesis of these novel copolymers is accomplished with ATRP, yielding low polydispersity and control of the block copolymer architecture. Well defined macromolecular characteristics are required to tailor the phase behavior of these materials. (2) Characterize relationship between the size and shape of pentablock copolymer micelles and gel structure and the pH and temperature of the copolymer solutions with SAXS, SANS and CryoTEM. (3) Evaluate the temperature and pH induced phase separation and macroscopic self-assembly phenomenon of the pentablock copolymer. (4) Utilize the knowledge gained from first three goals to design and formulate drug delivery formulations based on the multi

Synthesis and characterization of lanthanide-based luminescent nanoparticles: toward new bio-labels

International Nuclear Information System (INIS)

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

Synthesis, characterization, and subcellular localization studies of amino acid-substituted porphyrinic pigments

Science.gov (United States)

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

Synthesis and characterization of nanostructured powders of hydroxyapatite and β-calcium phosphate

Energy Technology Data Exchange (ETDEWEB)

Prants, W.T.; Muller, D.T.; Orzechowski, L.G.; Feit, G.; Delima, S.A.; Camargo, N.H.A.; Gemelli, E., E-mail: w_prants@hotmail.com, E-mail: danielt_muller@yahoo.com.br, E-mail: sarahamindelima@hotmail.com, E-mail: dem2nhac@joinville.udesc.br, E-mail: gemelli@joinville.udesc.br [Universidade do Estado de Santa Catarina (UDESC), Joinville, SC (Brazil). Campus Universitario Prof. Avelino Marcante

2009-07-01

Biphasic calcium phosphate (BCP) bioceramics are composed in a general manner from a mixture between hydroxyapatite (HA), and β-calcium phosphate. In the recent years, the BCP bioceramics are pointed out in researches from regeneration and reconstitution in osseous tissue, in reason of their similar mineralogical characteristics of the human bone structure, as great biodegradation, absorption and formation of precocious osseous tissue. The biphasic materials (BCP) are detached for use in medical and dental application, as filling bone cavities, maxillofacial treatment, medicaments discharge for treatment cancerous osteomyelitis and antibiotics discharge related with orthopedic injuries reparation. The aim of this work focused in synthesis and characterization of hydroxyapatite and β-calcium phosphate. The presented results are related with the mineralogical characterization with X-ray diffraction, thermal behavior with Differential Scanning Calorimetry and Dilatometer. The Scanning Electronic Microscopy (SEM) was used to help in the morphological characterization of the nanostructured powders. (author)

Synthesis and characterization of nanostructured powders of hydroxyapatite and β-calcium phosphate

International Nuclear Information System (INIS)

Prants, W.T.; Muller, D.T.; Orzechowski, L.G.; Feit, G.; Delima, S.A.; Camargo, N.H.A.; Gemelli, E.

2009-01-01

Biphasic calcium phosphate (BCP) bioceramics are composed in a general manner from a mixture between hydroxyapatite (HA), and β-calcium phosphate. In the recent years, the BCP bioceramics are pointed out in researches from regeneration and reconstitution in osseous tissue, in reason of their similar mineralogical characteristics of the human bone structure, as great biodegradation, absorption and formation of precocious osseous tissue. The biphasic materials (BCP) are detached for use in medical and dental application, as filling bone cavities, maxillofacial treatment, medicaments discharge for treatment cancerous osteomyelitis and antibiotics discharge related with orthopedic injuries reparation. The aim of this work focused in synthesis and characterization of hydroxyapatite and β-calcium phosphate. The presented results are related with the mineralogical characterization with X-ray diffraction, thermal behavior with Differential Scanning Calorimetry and Dilatometer. The Scanning Electronic Microscopy (SEM) was used to help in the morphological characterization of the nanostructured powders. (author)

Ionic Liquids: Radiation Chemistry, Solvation Dynamics and Reactivity Patterns

International Nuclear Information System (INIS)

Wishart, J.F.

2011-01-01

Ionic liquids (ILs) are a rapidly expanding family of condensed-phase media with important applications in energy production, nuclear fuel and waste processing, improving the efficiency and safety of industrial chemical processes, and pollution prevention. ILs generally have low volatilities and are combustion-resistant, highly conductive, recyclable and capable of dissolving a wide variety of materials. They are finding new uses in chemical synthesis, catalysis, separations chemistry, electrochemistry and other areas. Ionic liquids have dramatically different properties compared to conventional molecular solvents, and they provide a new and unusual environment to test our theoretical understanding of primary radiation chemistry, charge transfer and other reactions. We are interested in how IL properties influence physical and dynamical processes that determine the stability and lifetimes of reactive intermediates and thereby affect the courses of reactions and product distributions. We study these issues by characterization of primary radiolysis products and measurements of their yields and reactivity, quantification of electron solvation dynamics and scavenging of electrons in different states of solvation. From this knowledge we wish to learn how to predict radiolytic mechanisms and control them or mitigate their effects on the properties of materials used in nuclear fuel processing, for example, and to apply IL radiation chemistry to answer questions about general chemical reactivity in ionic liquids that will aid in the development of applications listed above. Very early in our radiolysis studies it became evident that the slow solvation dynamics of the excess electron in ILs (which vary over a wide viscosity range) increase the importance of pre-solvated electron reactivity and consequently alter product distributions and subsequent chemistry. This difference from conventional solvents has profound effects on predicting and controlling radiolytic yields

Polypyrrole-silver Nanocomposite: Synthesis and Characterization

Directory of Open Access Journals (Sweden)

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.

Synthesis and characterization of titanium oxide/bismuth sulfide nanorods for solar cells applications

International Nuclear Information System (INIS)

Solis, M.; Rincon, M. E.

2008-01-01

In the present work is showed the synthesis and characterization of titanium oxide/bismuth sulfide nanowires hetero-junctions for solar cells applications. Conductive glass substrates (Corning 25 x 75 mm) were coated with a thin layer of sol-gel TiO2 and used as substrates for the subsequent deposition of bismuth sulfide nanorods (BN). TiO2 films (∼400 nm) were deposited with a semiautomatic immersion system with controlled immersion/withdraw velocity, using titanium isopropoxide as the titania precursor [1]. For BN synthesis and deposition, the solvo-thermal method was used, introducing air annealed TiO2-substrates in the autoclave. The typical bilayer TiO2/BN hetero-junction was 600 nm thick. The synthesized materials (powders and films) were characterized by X-Ray Diffraction, Scanning Electron Microscopy, and UV-Visible Spectroscopy. Anatase was the crystalline phase of TiO2, while bismuth sulfide nanotubes show a diffraction pattern characteristic of bismuthinite distorted by the preferential growth of some planes [2-4]. The optoelectronic characterization of TiO2/NB hetero-junctions was compared with hetero-junctions obtained by sensitizing TiO2 with chemically deposited bismuth sulfide films. Bismuth sulfide nanowires are 2µm long and 70nm wide (aspect ratio L/D = 43), while chemically deposited bismuth sulfide have L/D = 1, therefore the effect of particle size evaluation and geometry in the photosensitization phenomena will be discussed in the context of new materials for solar-cells applications. (Full text)

Synthesis, characterization, and photocatalytic properties of core/shell mesoporous silica nanospheres supporting nanocrystalline titania

International Nuclear Information System (INIS)

Cendrowski, K.; Chen, X.; Zielinska, B.; Kalenczuk, R. J.; Rümmeli, M. H.; Büchner, B.; Klingeler, R.; Borowiak-Palen, E.

2011-01-01

The facile bulk synthesis of silica nanospheres makes them an attractive support for the transport of chemical compounds such as nanocrystalline titanium dioxide. In this contribution we present a promising route for the synthesis of mesoporous silica nanospheres (m-SiO 2 ) with diameter in range 200 nm, which are ideal supports for nanocrystalline titanium dioxide (TiO 2 ). The detailed microscopic and spectroscopic characterizations of core/shell structure (m-SiO 2 /TiO 2 ) were conducted. Moreover, the photocatalytic potential of the nanostructures was investigated via phenol decomposition and hydrogen generation. A clear enhancement of photoactivity in both reactions as compared to commercial TiO 2 -Degussa P25 catalyst is detected.

Synthesis, characterization, and photocatalytic properties of core/shell mesoporous silica nanospheres supporting nanocrystalline titania

Science.gov (United States)

Cendrowski, K.; Chen, X.; Zielinska, B.; Kalenczuk, R. J.; Rümmeli, M. H.; Büchner, B.; Klingeler, R.; Borowiak-Palen, E.

2011-11-01

The facile bulk synthesis of silica nanospheres makes them an attractive support for the transport of chemical compounds such as nanocrystalline titanium dioxide. In this contribution we present a promising route for the synthesis of mesoporous silica nanospheres (m-SiO2) with diameter in range 200 nm, which are ideal supports for nanocrystalline titanium dioxide (TiO2). The detailed microscopic and spectroscopic characterizations of core/shell structure (m-SiO2/TiO2) were conducted. Moreover, the photocatalytic potential of the nanostructures was investigated via phenol decomposition and hydrogen generation. A clear enhancement of photoactivity in both reactions as compared to commercial TiO2-Degussa P25 catalyst is detected.

Synthesis and characterization of rhodium sulfide nanoparticles and thin films

International Nuclear Information System (INIS)

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

Synthesis and characterization of rhodium sulfide nanoparticles and thin films

Energy Technology Data Exchange (ETDEWEB)

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.

Nanoscale Synthesis and Characterization Laboratory Annual Report 2005

Energy Technology Data Exchange (ETDEWEB)

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.

Features of Onset and Clinical Course of Reactive Arthritis in Children

Directory of Open Access Journals (Sweden)

I.S. Lebets

2013-09-01

Results. Reactive arthritis of chlamydial etiology is characterized by lesion of large and medium-sized joints of the lower limbs, which is often accompanied by short-term morning stiffness and rapid onset of transient hypomyatrophy. Reiter’s disease may develop rarely. Mycoplasma-induced reactive arthritis is characterized by debut with arthritis of knee, ankle, wrist and small joints of the hand, the development of bursitis and hypomyatrophy. Feature of Ureaplasma arthritis is the formation of bursitis in the heel and tendinitis. Reactive arthritis associated with elevated titers to antistreptolysin O differs with polymorphism of articular syndrome manifestations and, to some extent, of similarity with juvenile rheumatoid arthritis. Unspecified reactive arthritis has a number of the general features with others reactive arthritis and it is characterized by rather benign clinical course, long preservation of joints function and low laboratory activity. Relapse rate of reactive arthritis increases with an increase of duration of illness.

Synthesis, characterization and properties

Indian Academy of Sciences (India)

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.

Synthesis And Characterization Of Mebrofenin For Hepatobiliary Imaging

International Nuclear Information System (INIS)

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%

Synthesis and characterization of poly aniline/wood and poly aniline/carbon composites

International Nuclear Information System (INIS)

Kanwal, F.; Siddiqi, S.A.; Tasleem, S.

2009-01-01

Conducting polymers have shown many applications in the field of nano science, nano technology and nuclear science. Poly aniline (PAN I) is the most studied conducting polymer due to its environmental stability, easy availability of its raw materials, and simple synthesis. We have synthesized poly aniline and two of its conducting composites i.e., poly aniline-carbon and poly aniline-wood in acidic medium (HCI) using K/sub 2/Cr/sub 2/O/sub 7/ as oxidizing agent. All samples were characterized by FTIR and four-probe d.c. conductivity methods The synthesis was carried out at two different temperatures (0 degree C and -5 degree C) and it was found that the yield and conductivity were maximum at lower temperature (-5 degree C). The poly aniline-carbon composites showed enhanced conductivity whereas poly aniline-wood composites showed reduced conductivity when compared with the conductivity of pure poly aniline. (author)

Synthesis, structure characterization and catalytic activity of nickel tungstate nanoparticles

Science.gov (United States)

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

2012-12-01

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

Quantitative reactive modeling and verification.

Science.gov (United States)

Henzinger, Thomas A

Formal verification aims to improve the quality of software by detecting errors before they do harm. At the basis of formal verification is the logical notion of correctness , which purports to capture whether or not a program behaves as desired. We suggest that the boolean partition of software into correct and incorrect programs falls short of the practical need to assess the behavior of software in a more nuanced fashion against multiple criteria. We therefore propose to introduce quantitative fitness measures for programs, specifically for measuring the function, performance, and robustness of reactive programs such as concurrent processes. This article describes the goals of the ERC Advanced Investigator Project QUAREM. The project aims to build and evaluate a theory of quantitative fitness measures for reactive models. Such a theory must strive to obtain quantitative generalizations of the paradigms that have been success stories in qualitative reactive modeling, such as compositionality, property-preserving abstraction and abstraction refinement, model checking, and synthesis. The theory will be evaluated not only in the context of software and hardware engineering, but also in the context of systems biology. In particular, we will use the quantitative reactive models and fitness measures developed in this project for testing hypotheses about the mechanisms behind data from biological experiments.

Synthesis and characterization of iron nano particles for the arsenic removal in water

International Nuclear Information System (INIS)

Gutierrez M, O. E.

2011-01-01

The synthesis of iron nanoparticles for the removal of metallic ions in polluted waters has been during the last years study topic for different world organizations. This work presents a synthesis method of conditioned coal with iron nanoparticles starting from the use of leaves of pineapple crown, with the purpose of using it in arsenic removal processes in aqueous phase. For the synthesis of this material, the leaves of the pineapple crown were used like supports structure of the iron nanoparticles. First, the pyrolysis appropriate temperature was determined. For the preparation of the support material, this had contact with a ferric nitrate and hexamine solution, because the preparation of the material and the coal synthesis were realized during the pyrolysis process, where the hexamine molecules and the ferric nitrate react, causing the reduction of the iron particles and their dispersion on the support material, obtaining as product a conditioned coal with iron nanoparticles. For the characterization of the materials were used techniques as: Scanning electron microscopy, Transmission electron microscopy, X-Rays Diffraction), X-Ray photoelectron spectroscopy and Moessbauer spectroscopy; moreover was determined the isoelectric point and the density of surface sites. The arsenic sorption capacity of the materials was evaluated by means of the methodology type lots where was determined the sorption kinetics and isotherms in terms of arsenic concentration and mass. (Author)

Development and optimisation of synthesis, characterisation and physical properties of solid materials for strip conductors; purpose oriented synthesis of novel systems. Final report

International Nuclear Information System (INIS)

Guenther, W.; Schoellhorn, R.

1995-06-01

The project reported is part of studies into the performance of HTSC, and was responsible for the following essential tasks: synthesis, characterisation, and optimisation of oxocuprates of the type (RE)Ba 2 Cu 3 O 7 , examination of the relevant corrosion processes and reactivity of the phases, and synthesis of novel systems guided by special model concepts, applying kinetics-controlled low-temperature synthesis. (orig./MM) [de

Synthesis and characterization of the natural and burned hydrotalcite

International Nuclear Information System (INIS)

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)

Synthesis and Characterization Pectin-Carboxymethyl Chitosan crosslinked PEGDE as biosorbent of Pb(II) ion

Science.gov (United States)

Hastuti, Budi; Siswanta, Dwi; Mudasir; Triyono

2018-01-01

Pectin and chitosan are biodegradable polymers, potentially applied as a heavy metal adsorbents. Unfortunately both biosorbents pectin and chitosan have a weakness in acidic media. For this purpose required modified pectin and chitosan. The modified adsorben is intended to obtain a stable adsorbent and resistance under acid. The research was done by experimental method in laboratory. The stages of this research are the synthesis of carboxymethyl chitosan (CMC), synthesis of Pec-CMC-PEGDE film adsorbent, stabily test under acid, the characterization of active group using FTIR, stability characterization of Pec-CMC-PEGDE powder adsorbent using XRD, termo stability using DTA-TGA. The results of the research have shown that: pectin and CMC can be cross-linked using PEGDE crosslinking agent, the film adsorbent was stable under HCl 1 M, the film adsorbent have active group comprise of carboxylate and amine groups. The result of characterization using XRD, shows that the adsorbent is semi-crystalline. Base on termo stability, the film adsorbent Pec-CMC-PEGDE stable up to 600°C. The film can be applied as an adsobent of Pb (II) ion remediation. The optimum pH of pec-CMC-PEGDE in adsorbed of Pb(II) was reached at pH 5 with 99.99% absorbent adsorbed and of and adsorption capacity was 46.11 mg/g.

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

African Journals Online (AJOL)

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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, ...

Synthesis and structural characterization of piperazino-modified DNA that favours hybridization towards DNA over RNA

DEFF Research Database (Denmark)

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...

Reactivity and Synthetic Applications of 4,5-Dicyanopyridazine: An Overview

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Donatella Giomi

2010-03-01

Full Text Available Despite the poor reputation of electron-deficient pyridazines in intermolecular Hetero Diels-Alder (HDA reactions, 4,5-dicyanopyridazine (DCP showed a surprising reactivity as a heterocyclic azadiene in inverse electron-demand HDA processes with different dienophiles. The use of alkenes, alkynes and enamines as 2p electron counterparts afforded dicyanocyclohexa-1,3-dienes and substituted phthalonitriles, respectively, while the use of suitable bis-dienophiles provides a general strategy for the one-pot synthesis of polycyclic carbo- and hetero-cage systemsthrough pericyclic three-step homodomino processes. HDA reactions with heterocyclic dienophiles allowed direct benzoannelation: in particular, pyrrole and indole derivatives were converted to dicyano-indoles and -carbazoles. In addition an unprecedented reactivity of DCP as a very reactive heterocyclic electrophile at the C-4 carbon was also evidenced: by changing the experimental conditions, cyanopyrrolyl- and cyanoindolyl-pyridazines were obtained through reactions of pyrrole and indole systems as carbon nucleophiles in formal SNAr2 processes where a CN group of DCP acts as leaving group. Thus, careful control of the reaction conditions allows exploitation of both pathways for the synthesis of different classes of heterocyclic derivatives.

Hydrothermal synthesis of silica rich zeolites and microporous martials

International Nuclear Information System (INIS)

Durrani, S.K.; Chughtai, N.A.; Akhtar, J.; Arif, M.; Ahmed, M.

1999-01-01

A fast crystallization method for synthesis of silica rich aluminosilicate and ferro silicate zeotype materials has been reported. The method also permits for the complete crystallization of silico alumino phosphate microporous materials. Aluminosilicate and ferro silicate silica rich zeotype materials and silico alumino phosphate microporous materials have been synthesized from the reaction mixture of colloidal silica sol, reactive aluminum, ferrous and phosphorous salts, and the essential organic templates at 373-473 K and were characterized by TG/DTA/DSC, X-ray diffraction, scanning electron microscopy and other analytical techniques. Crystallinity and unit cell parameters of the synthesized materials were found to be the function of Al and Fe content of zeolites. (author)

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

International Nuclear Information System (INIS)

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

Surface decoration through electrostatic interaction leading to enhanced reactivity: Low temperature synthesis of nanostructured chromium borides (CrB and CrB2)

International Nuclear Information System (INIS)

Menaka,; Kumar, Bharat; Kumar, Sandeep; Ganguli, A.K.

2013-01-01

The present study describes a novel low temperature route at ambient pressure for the synthesis of nanocrystalline chromium borides (CrB and CrB 2 ) without using any flux or additives. The favorable and intimate mixing of nanoparticles of chromium acetate (Cr source) and boron forms an active chromium–boron precursor which decomposes at much lower temperature (400 °C) to form CrB (which is ∼1000 °C less than the known ambient pressure synthesis). The chromium acetate nanoparticles (∼5 nm) decorate the larger boron particles (150–200 nm) due to electrostatic interactions resulting from opposing surface charges of boron (zeta potential:+48.101 mV) and chromium acetate (zeta potential:−4.021 mV) in ethanolic medium and is evident in the TEM micrographs. The above method leads to the formation of pure CrB film like structure at 400 °C and nanospheres (40–60 nm) at 600 °C. Also, chromium diboride (CrB 2 ) nanoparticles (25 nm) could be obtained at 1000 °C. - Graphical abstract: Variation of surface charge of reactants, precursor and the products, chromium borides (CrB and CrB 2 ). Highlights: ► Novel borothermal reduction process for synthesis of chromium boride. ► Significant lowering of reaction temperature to obtain nanocrystalline chromium boride. ► Enhanced reactivity due to appropriate surface interactions

Synthesis and Characterization of Pine Needles Reinforced RF Matrix Based Biocomposites

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A. S. Singha

2008-01-01

Full Text Available Synthesis and characterization of pine needles reinforced thermosetting resin (Resorcinol-Formaldehyde which is most suitable as composite matrix has been reported. The polycondensation reaction between resorcinol and formaldehyde (RF in different molar ratios has been applied to the synthesis of RF polymer matrix. A thermosetting resin based composite, containing approximately 10, 20, 30 and 40% of natural fiber by weight, has been obtained by adding pine needles to the Resorcinol-Formaldehyde (RF resin. The mechanical properties of randomly oriented intimately mixed particle reinforced (Pine needles composites were determined. Effect of fiber loading in terms of weight % on mechanical properties such as tensile, compressive, and flexural and wear properties have also been evaluated. The reinforcing of the resin with Pine needles was accomplished in particle size of 200 micron by employing optimized resin. Present work reveals that mechanical properties of the RF resin increases to extensive extent when reinforced with Pine needles. Thermal (TGA/DTA and morphological studies (SEM of the resin, fiber and polymer composites thus synthesized have also been carried out.

Copper nanoparticles mediated by chitosan: synthesis and characterization via chemical methods.

Science.gov (United States)

Usman, Muhammad Sani; Ibrahim, Nor Azowa; Shameli, Kamyar; Zainuddin, Norhazlin; Yunus, Wan Md Zin Wan

2012-12-14

Herein we report a synthesis of copper nanoparticles (Cu-NPs) in chitosan (Cts) media via a chemical reaction method. The nanoparticles were synthesized in an aqueous solution in the presence of Cts as stabilizer and CuSO(4)·5H(2)O precursor. The synthesis proceeded with addition of NaOH as pH moderator, ascorbic acid as antioxidant and hydrazine( )as the reducing agent. The characterization of the prepared NPs was done using ultraviolet-visible spectroscopy, which showed a 593 nm copper band. The Field Emission Scanning Electron Microscope (FESEM) images were also observed, and found to be in agreement with the UV-Vis result, confirming the formation of metallic Cu-NPs. The mean size of the Cu-NPs was estimated to be in the range of 35-75 nm using X-ray diffraction. XRD was also used in analysis of the crystal structure of the NPs. The interaction between the chitosan and the synthesized NPs was studied using Fourier transform infrared (FT-IR) spectroscopy, which showed the capping of the NPs by Cts.

Novel Green Synthesis and Characterization of Nanopolymer ...

African Journals Online (AJOL)

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 ...

Synthesis and antibacterial characterization of sustainable nanosilver using naturally-derived macromolecules

Energy Technology Data Exchange (ETDEWEB)

Osonga, Francis J.; Kariuki, Victor M.; Yazgan, Idris; Jimenez, Apryl; Luther, David; Schulte, Jürgen; Sadik, Omowunmi A., E-mail: osadik@binghamton.edu

2016-09-01

Greener nanosynthesis utilizes fewer amounts of materials, water, and energy; while reducing or replacing the need for organic solvents. A novel approach is presented using naturally-derived flavonoids including Quercetin pentaphosphate (QPP), Quercetin sulfonic acid (QSA) and Apigenin Triphosphate (ATRP). These water soluble, phosphorylated flavonoids were utilized both as reducing agent and stabilizer. The synthesis was achieved at room temperature using water as a solvent and it requires no capping agents. The efficiency of the resulting silver nanoparticle synthesis was compared with naturally-occurring flavonoid such as Quercetin (QCR). Results show that QCR reduced Ag{sup +} faster followed by QPP, QSA and ATRP respectively. This is the first evidence of direct utilization of QCR for synthesis of silver nanoparticles (AgNPs) in water. The percentage conversion of Ag{sup +} to Ag{sup 0} was determined to be 96% after 35 min. The synthesized nanoparticles were characterized using Transmission electron microscopy (TEM), Energy dispersive absorption spectroscopy (EDS), UV–vis spectroscopy, High resolution TEM (HR-TEM) with selected area electron diffraction (SAED). The particle sizes ranged from 2 to 80 nm with an average size of 22 nm and in the case of ATRP, the nanoparticle shapes varied from spherical to hexagonal with dispersed particle size ranging from 2 to 30 nm. Crystallinity was confirmed by XRD and the SAED of (111), (200), and the fringes observed in HRTEM images. Results were in agreement with the UV resonance peaks of 369–440 nm. The particles also exhibit excellent antibacterial activity against Staphylococcus epidermidis, Escherichia coli and Citrobacter freundii in water. - Highlights: • Greener nanosilver prepared using flavonoid derivatives • Synthesized nanosilver exhibits exhibit antibacterial activity. • Approach suitable for industrial synthesis.

Structural and photocarrier radiometric characterization of Cux(CdTe)yOz thin films growth by reactive sputtering

International Nuclear Information System (INIS)

Velazquez-Hernandez, R.; Rojas-Rodriguez, I.; Carmona-Rodriguez, J.; Jimenez-Sandoval, S.; Rodriguez-Garcia, M.E.

2011-01-01

This research presents a structural and photocarrier radiometric (PCR) characterization of Cu x (CdTe) y O z thin films grown using reactive radiofrequency co-sputtering. Electronic distribution induced by variations in dopant concentration as a function of the position was studied using photocarrier radiometric images. Optical and structural characterization of these thin films was carried out by using micro Raman spectroscopy and X-ray diffraction. Due to its nondestructive and noncontact characteristics, the PCR is an excellent technique that permits one to obtain details of lateral electronic distribution across the sample. It was found that Cu target power influences the electronic distribution and produces different phases such as Cu 2 Te and CdO.

SYNTHESIS, CHARACTERIZATION AND DENSITY FUNCTIONAL ...

African Journals Online (AJOL)

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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 ...

Using Spectrophotometric Titrations To Characterize Humic Acid Reactivity at Environmental Concentrations

International Nuclear Information System (INIS)

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)

Using Spectrophotometric Titrations To Characterize Humic Acid Reactivity at Environmental Concentrations

Energy Technology Data Exchange (ETDEWEB)

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)

Self-organised synthesis of Rh nanostructures with tunable chemical reactivity

Directory of Open Access Journals (Sweden)

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.

Polar red-emitting rhodamine dyes with reactive groups: synthesis, photophysical properties, and two-color STED nanoscopy applications.

Science.gov (United States)

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 �

Chemical and mineralogical characterization of highly and less reactive coal from Northern Natal and Venda-Pafuri coalfields in South Africa

Science.gov (United States)

Kataka, M. O.; Matiane, A. R.; Odhiambo, B. D. O.

2018-01-01

Spontaneous combustion of coal is a major hazard associated with the coal mining industry over centuries. It also a major cause of underground fires in South African collieries and in opencast operations, spoil heaps and stockpiles. Spontaneous combustion incidents are manifested in all major aspects of coal mining namely, underground mining, surface mining, including during sea-borne transportation, storage and waste disposal. Previous studies indicate that there are various factors (both intrinsic and extrinsic) that influence the spontaneous combustion of coals. This paper characterizes highly reactive coal from the Vryheid coalfields and less reactive coal from at Venda-Pafuri coalfield, to identify and delineate some intrinsic coal parameters that are considered to be most critical in terms of heat 'generation' and relationships between the two coals types by tracing their similarities and differences in their spontaneous combustion parameters. Various tests were carried out to characterize these coals in terms of their intrinsic properties, namely: ultimate, proximate, petrographic analysis and Glasser spontaneous tests. The ultimate and proximate analysis showed that spontaneous coal has high contents of carbon, oxygen, and volatile matter as compared to non-spontaneous coal, making it more susceptible to spontaneous combustion. Non-spontaneous coal has higher ash content than the spontaneous coal. Furthermore, the petrographic analysis showed that spontaneous coal has high total reactivity compared to the non-spontaneous coal. Results from Glasser spontaneous test indicate that spontaneous coal absorbs more oxygen than non-spontaneous coal, which explains why spontaneous coal is more susceptible to spontaneous combustion. High reactive coal has low values of critical self-heating temperature (CSHT), indicating that this coal has potential of spontaneous ignition.

Experimental investigation of aminoacetonitrile formation through the Strecker synthesis in astrophysical-like conditions: reactivity of methanimine (CH2NH), ammonia (NH3), and hydrogen cyanide (HCN)

Science.gov (United States)

Danger, G.; Borget, F.; Chomat, M.; Duvernay, F.; Theulé, P.; Guillemin, J.-C.; Le Sergeant D'Hendecourt, L.; Chiavassa, T.

2011-11-01

Context. Studing chemical reactivity in astrophysical environments is an important means for improving our understanding of the origin of the organic matter in molecular clouds, in protoplanetary disks, and possibly, as a final destination, in our solar system. Laboratory simulations of the reactivity of ice analogs provide important insight into the reactivity in these environments. Here, we use these experimental simulations to investigate the Strecker synthesis leading to the formation of aminoacetonitrile in astrophysical-like conditions. The aminoacetonitrile is an interesting compound because it was detected in SgrB2, hence could be a precursor of the smallest amino acid molecule, glycine, in astrophysical environments. Aims: We present the first experimental investigation of the formation of aminoacetonitrile NH2CH2CN from the thermal processing of ices including methanimine (CH2NH), ammonia (NH3), and hydrogen cyanide (HCN) in interstellar-like conditions without VUV photons or particules. Methods: We use Fourier Transform InfraRed (FTIR) spectroscopy to monitor the ice evolution during its warming. Infrared spectroscopy and mass spectroscopy are then used to identify the aminoacetonitrile formation. Results: We demonstrate that methanimine can react with -CN during the warming of ice analogs containing at 20 K methanimine, ammonia, and [NH4+ -CN] salt. During the ice warming, this reaction leads to the formation of poly(methylene-imine) polymers. The polymer length depend on the initial ratio of mass contained in methanimine to that in the [NH4+ -CN] salt. In a methanimine excess, long polymers are formed. As the methanimine is progressively diluted in the [NH4+ -CN] salt, the polymer length decreases until the aminoacetonitrile formation at 135 K. Therefore, these results demonstrate that aminoacetonitrile can be formed through the second step of the Strecker synthesis in astrophysical-like conditions.

Tuned apatitic materials: Synthesis, characterization and potential antimicrobial applications

Science.gov (United States)

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.

SYNTHESIS AND CHARACTERIZATION OF FUNCTIONALIZED ...

African Journals Online (AJOL)

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.

Photoluminescent silicon nanocrystals with chlorosilane surfaces - synthesis and reactivity

Science.gov (United States)

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

Synthesis and characterization of functional magnetic nanocomposites

Science.gov (United States)

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.

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

Energy Technology Data Exchange (ETDEWEB)

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)

Synthesis and characterization of an additive type super plasticizers obtained from plastics cups of polystyrene

International Nuclear Information System (INIS)

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

Synthesis and characterization of surfactant assisted Mn2+ doped ZnO nanocrystals

Directory of Open Access Journals (Sweden)

N. Shanmugam

2016-09-01

Full Text Available We report the synthesis and characterization of Mn doped ZnO nanocrystals, both in the free standing and PVP capped particle forms. The nanocrystals size could be controlled by capping them with polyvinylpyrollidone and was estimated by X-ray diffraction and transmission electron microscopy. The chemical compositions of the products were characterized by FT-IR spectroscopy. UV–Vis absorption spectroscopy measurements reveal that the capping of ZnO leads to blue shift due to quantum confinement effect. The morphology of the particles was evaluated by Scanning Electron Microscopy (SEM and Transmission Electron Microscopy (TEM. Both the Thermo Gravimetric Analysis (TGA and Differential Thermal Analysis (DTA curves of the ZnO show no further weight loss and thermal effect at a temperature above 510 °C.

Synthesis of an oxo trialkyl tungsten fluoride complex and its dual reactivity with silica dehydroxylated at high temperature

KAUST Repository

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.

Synthesis of an oxo trialkyl tungsten fluoride complex and its dual reactivity with silica dehydroxylated at high temperature

KAUST Repository

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.

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

DEFF Research Database (Denmark)

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....

Synthesis of SnO2 nanoparticles through the controlled precipitation route

International Nuclear Information System (INIS)

Ibarguen, C. Ararat; Mosquera, A.; Parra, R.; Castro, M.S.; Rodriguez-Paez, J.E.

2007-01-01

The controlled precipitation method allowed to the synthesis of SnO 2 with advantageous specific properties, such as size and shape employing an aqueous SnCl 2 .2H 2 O solution as precursor. Through XRD analyses, the optimum pH value of the solution that yielded the desired product was found to be 6.25. After a thermal treatment at 600 deg. C, the final powder presented an average particle size below 50 nm with a surface area of 19 m 2 g -1 and a large reactivity. The evolution of the most important functional groups during the steps involved in this synthesis route is explained in view of the results obtained with FTIR and XRD. A thorough discussion on the different intermediates involved in the whole process is presented on the basis of hydrolysis and condensation reactions. The conclusions are supported with a complete characterization through differential and gravimetric thermal analysis (DTA/TGA), electron microscopies (SEM/TEM) and surface area determinations (BET)

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

Science.gov (United States)

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.

Synthesis and characterization of oxovanadium (IV) dithiocarbamates with pyridine

Energy Technology Data Exchange (ETDEWEB)

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)

ROLE OF STEM CELL FACTOR IN THE REACTIVATION OF HUMAN FETAL HEMOGLOBIN

Directory of Open Access Journals (Sweden)

Marco Gabbianelli

2009-11-01

In vitro and in vivo models have led to the identification of several chemical compounds able to reactivate HbF synthesis in adult erythroid cells. Although the impact of these HbF inducers, including hypomethylating agents, histone deacetylase inhibitors and hydroxyurea, was clear on the natural history of sickle cell anemia, the benefit on the clinical course of -thalassemia was only limited: particularly, the toxicity and the modest increase in γ-globin reactivation indicated the need for improved agents able to induce higher levels of HbF. In the present review we describe the biologic properties of Stem Cell Factor (SCF, a cytokine sustaining the survival and proliferation of erythroid cells, that at pharmacological doses acts as a potent stimulator of HbF synthesis in adult erythroid cells.

Synthesis and characterization of catalysts for the selective transformation of biomass-derived materials

Science.gov (United States)

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

Synthesis and characterization of monodispersed orthorhombic manganese oxide nanoparticles produced by Bacillus sp. cells simultaneous to its bioremediation

Energy Technology Data Exchange (ETDEWEB)

Sinha, Arvind [Enzyme and Microbial Biochemistry Laboratory, Department of Chemistry, Indian Institute of Technology, Delhi, Hauz Khas, New Delhi 110 016 (India); Singh, Vidya Nand; Mehta, Bodh Raj [Thin Film Laboratory, Department of Physics, Indian Institute of Technology, Delhi Hauz Khas, New Delhi 110016 (India); Khare, Sunil Kumar, E-mail: skhare@rocketmail.com [Enzyme and Microbial Biochemistry Laboratory, Department of Chemistry, Indian Institute of Technology, Delhi, Hauz Khas, New Delhi 110 016 (India)

2011-08-30

Highlights: {yields} An efficient process wherein remediated manganese is synthesized into nanoparticles. {yields} A microbial process for manganese nanoparticle synthesis from metal waste streams. {yields} Nanoparticles characterized as monodispersed, spherical and 4.62 {+-} 0.14 nm sized MnO{sub 2}. -- Abstract: A heavy metal resistant strain of Bacillus sp. (MTCC10650) is reported. The strain exhibited the property of bioaccumulating manganese, simultaneous to its remediation. The nanoparticles thus formed were characterized and identified using energy dispersive X-ray analysis (EDAX), high resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), powder X-ray diffraction (PXRD) and atomic force microscopy (AFM). When the cells were challenged with manganese, the cells effectively synthesized nanoparticles of average size 4.62 {+-} 0.14 nm. These were mostly spherical and monodispersed. The ex situ enzymatically synthesized nanoparticles exhibited an absorbance maximum at 329 nm. These were more discrete, small and uniform, than the manganese oxide nanoparticles recovered after cell sonication. The use of Bacillus sp. cells seems promising and advantageous approach. Since, it serves dual purposes of (i) remediation and (ii) nanoparticle synthesis. Considering the increasing demand of developing environmental friendly and cost effective technologies for nanoparticle synthesis, these cells can be exploited for the remediation of manganese from the environment in conjunction with development of a greener process for the controlled synthesis of manganese oxide nanoparticles.

Synthesis and characterization of monodispersed orthorhombic manganese oxide nanoparticles produced by Bacillus sp. cells simultaneous to its bioremediation

International Nuclear Information System (INIS)

Sinha, Arvind; Singh, Vidya Nand; Mehta, Bodh Raj; Khare, Sunil Kumar

2011-01-01

Highlights: → An efficient process wherein remediated manganese is synthesized into nanoparticles. → A microbial process for manganese nanoparticle synthesis from metal waste streams. → Nanoparticles characterized as monodispersed, spherical and 4.62 ± 0.14 nm sized MnO 2 . -- Abstract: A heavy metal resistant strain of Bacillus sp. (MTCC10650) is reported. The strain exhibited the property of bioaccumulating manganese, simultaneous to its remediation. The nanoparticles thus formed were characterized and identified using energy dispersive X-ray analysis (EDAX), high resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), powder X-ray diffraction (PXRD) and atomic force microscopy (AFM). When the cells were challenged with manganese, the cells effectively synthesized nanoparticles of average size 4.62 ± 0.14 nm. These were mostly spherical and monodispersed. The ex situ enzymatically synthesized nanoparticles exhibited an absorbance maximum at 329 nm. These were more discrete, small and uniform, than the manganese oxide nanoparticles recovered after cell sonication. The use of Bacillus sp. cells seems promising and advantageous approach. Since, it serves dual purposes of (i) remediation and (ii) nanoparticle synthesis. Considering the increasing demand of developing environmental friendly and cost effective technologies for nanoparticle synthesis, these cells can be exploited for the remediation of manganese from the environment in conjunction with development of a greener process for the controlled synthesis of manganese oxide nanoparticles.

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

Directory of Open Access Journals (Sweden)

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.

Biogenic Synthesis, Characterization and Evaluation of Silver Nanoparticles from Aspergillus niger JX556221 Against Human Colon Cancer Cell Line HT-29.

Science.gov (United States)

Chengzheng, Wang; Jiazhi, Wen; Shuangjiang, Chen; Swamy, Mallappa Kumara; Sinniah, Uma Rani; Akhtar, Mohd Sayeed; Umar, Ahmad

2018-05-01

Nanobiotechnology has emerged as a promising technology to develop new therapeutically active nanomaterials. The present study was aimed to biosynthesize AgNPs extracellularly using Aspergillus niger JX556221 fungal extract and to evaluate their anticancer potential against colon cancer cell line, HT-29. UV-visible spectral characterization of the synthesized AgNPs showed higher absorption peak at 440 nm wavelength. Transmission Electron Microscopy (TEM) analysis revealed the monodispersed nature of synthesized AgNPs occurring in spherical shape with a size in the range of 20-25 nm. Further, characterization using Energy Dispersive Spectroscopy (EDX) confirmed the face-centred cubic crystalline structure of metallic AgNPs. FTIR data revealed the occurrence of various phytochemicals in the cell free fungal extract which substantiated the fungal extract mediated AgNPs synthesis. The cytotoxic effect of AgNPs was studied by using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The results evidenced the cytotoxic effect of AgNPs on HT-29 cell lines in a dose dependent manner. The highest activity was found at 100 μg/ml concentration after 24 h of incubation. Use of propidium iodide staining examination method confirmed the cytotoxic effect of AgNPs through inducing cell apoptosis. AgNPs cytotoxicity was found to be through elevating reactive oxygen species (ROS), and caspase-3 activation resulting in induced apoptosis. Therefore, this research finding provides an insight towards the development of novel anticancer agents using biological sources.

Synthesis and transport characterization of electrochemically deposited CdTe nanowires

Science.gov (United States)

Kaur, Jaskiran; Kaur, Harmanmeet; Singh, R. C.

2018-04-01

This paper reports the synthesis and characterization of CdTe nanowires. A thin polymeric films were irradiated with 80MeV Ag ions at a fluence of 8E7 ions/cm2, followed by UV irradiation and chemically etching in aqueous NaOH. Nanosizes go-through pores so formed were filled using a specially designed cell via electrodeposition. Nanowires so formed were further studied using SEM, I-V, UV and XRD analysis. SEM images show very smooth and uniform CdTe nanowires freely standing on the substrate. The in-situ I-V characteristics of nano-/micro structures was carried out at room temperature by leaving the structures embedded in the insulating template membrane itself.

Synthesis and characterization of PMMA/clay nanocomposites prepared by in situ polymerization assisted by sonication

International Nuclear Information System (INIS)

Prado, Bruna R.; Bartoli, Julio R.; Ito, Edson N.

2015-01-01

In this work is presented the synthesis of nanocomposites of poly(methyl methacrylate), PMMA, with organically montmorillonite (OMMT) modified clays by in situ polymerization assisted by sonication. A statistically designed experiment was used, central composing design (CCD), to study the effect of synthesis variables on the dispersion of nanoparticles in PMMA matrix. The processing and formulation factors studied were: energy of sonication and Flory-Huggins interaction parameter between PMMA and organoclay. The structural (XRD) and morphological (TEM) characterizations of the PMMA/OMMT nanocomposites are compared with the literature. It was observed significant exfoliation of OMMT modified with hydroxyl groups in the nanocomposites of PMMA, mainly at the low ultrasonic energy level (90 and 105 kJ) studied. (author)

Graphitic carbon nitride: Synthesis, characterization and photocatalytic decomposition of nitrous oxide

Energy Technology Data Exchange (ETDEWEB)

Praus, Petr, E-mail: petr.praus@vsb.cz [Institute of Environmental Technology, VŠB-Technical University of Ostrava, 17. Listopadu 15/2172, Ostrava 708 33 (Czech Republic); Department of Chemistry, Faculty of Metallurgy and Materials Engineering, VŠB-Technical University of Ostrava, 17. Listopadu 15/2172, Ostrava 708 33 (Czech Republic); Svoboda, Ladislav [Institute of Environmental Technology, VŠB-Technical University of Ostrava, 17. Listopadu 15/2172, Ostrava 708 33 (Czech Republic); Department of Chemistry, Faculty of Metallurgy and Materials Engineering, VŠB-Technical University of Ostrava, 17. Listopadu 15/2172, Ostrava 708 33 (Czech Republic); Ritz, Michal [Department of Chemistry, Faculty of Metallurgy and Materials Engineering, VŠB-Technical University of Ostrava, 17. Listopadu 15/2172, Ostrava 708 33 (Czech Republic); Troppová, Ivana; Šihor, Marcel; Kočí, Kamila [Institute of Environmental Technology, VŠB-Technical University of Ostrava, 17. Listopadu 15/2172, Ostrava 708 33 (Czech Republic)

2017-06-01

Graphitic carbon nitride (g-C{sub 3}N{sub 4}) was synthetized by condensation of melamine at the temperatures of 400–700 °C in air for 2 h and resulting products were characterized and finally tested for the photocatalytic decomposition of nitrous oxide. The characterization methods were elemental analysis, UV–Vis diffuse reflectance spectroscopy (DRS), photoluminescence (PL), Fourier transform infrared (FTIR) and Raman spectroscopy, measurement of specific surface area (SSA), X-ray powder diffraction (XRD), scanning (SEM) and transmission (TEM) electron microscopy. The XRD patterns, FTIR and Raman spectra proved the presence of g-C{sub 3}N{sub 4} at above 550 °C but the optimal synthesis temperature of 600–650 °C was found. Under these conditions graphitic carbon nitride of the overall empirical composition of C{sub 6}N{sub 9}H{sub 2} was formed. At lower temperatures g-C{sub 3}N{sub 4} with a higher content of hydrogen was formed but at higher temperatures g-C{sub 3}N{sub 4} was decomposed. At the temperatures above 650 °C, its exfoliation was observed. The photocatalytic experiments showed that the activity of all the samples synthetized at 400–700 °C was very similar, that is, within the range of experimental error (5 %). The total conversion of N{sub 2}O reached about 43 % after 14 h. - Highlights: • Graphitic carbon nitride (g-C{sub 3}N{sub 4}) was thermally synthetized from melamine in the range of 400–700 °C. • The optimal temperature was determined at 600–650 °C. • All synthesis products were properly characterized by physico-chemical methods. • Exfoliation of g-C{sub 3}N{sub 4} at above 600 °C was observed. • g-C{sub 3}N{sub 4} was used for the photocatalytic decomposition of N{sub 2}O.

Synthesis and characterization of MgO nanocrystals for biosensing applications

Energy Technology Data Exchange (ETDEWEB)

Li, Hongji [Tianjin Key Laboratory of Organic Solar Cells and Photochemical Conversion, School of Chemistry & Chemical Engineering, Tianjin University of Technology, Tianjin 300384 (China); Li, Mingji, E-mail: limingji@163.com [Tianjin Key Laboratory of Film Electronic and Communication Devices, School of Electronics Information Engineering, Tianjin University of Technology, Tianjin 300384 (China); Qiu, Guojun [Tianjin Key Laboratory of Organic Solar Cells and Photochemical Conversion, School of Chemistry & Chemical Engineering, Tianjin University of Technology, Tianjin 300384 (China); Li, Cuiping; Qu, Changqing; Yang, Baohe [Tianjin Key Laboratory of Film Electronic and Communication Devices, School of Electronics Information Engineering, Tianjin University of Technology, Tianjin 300384 (China)

2015-05-25

Highlights: • MgO nanocrystals were prepared using DC arc plasma jet CVD method. • The growth time does not exceed 10 min in process of the synthesis. • The samples were found to consist of cubic MgO nanobelts and nanosheets. • Nanocrystals contain contacts, rough edges, vacancies, and doping defects. • The samples exhibited excellent electrochemical biosensing properties. - Abstract: MgO nanocrystals were prepared using a simple direct current arc plasma jet chemical vapor deposition method. Magnesium nitrate was used as source material and Mo film was used as a substrate and catalyst. The high-temperature plasma produced ensured rapid synthesis of the MgO nanocrystals. The as-prepared nanocrystals were characterized by field-emission scanning electron microscopy, high-resolution transmission electron microscopy, X-ray diffraction, energy-dispersive spectroscopy, Fourier transform infrared spectrometry, ultraviolet–visible spectrophotometry, and photoluminescence measurements. The as-synthesized samples were found to consist of cubic MgO nanobelts and nanosheets with large surface areas and low coordination oxide ions, and contained numerous contacts, rough edges, vacancies, and doping defects. The nanostructures exhibited excellent electrochemical sensing properties with high-sensing sensitivity toward ascorbic acid. Their high electrocatalytic activity was attributed to the effect of defects and the surface electron transfer ability of the one-dimensional MgO nanobelts.

Stereodivergent synthesis with a programmable molecular machine

Science.gov (United States)

Kassem, Salma; Lee, Alan T. L.; Leigh, David A.; Marcos, Vanesa; Palmer, Leoni I.; Pisano, Simone

2017-09-01

It has been convincingly argued that molecular machines that manipulate individual atoms, or highly reactive clusters of atoms, with Ångström precision are unlikely to be realized. However, biological molecular machines routinely position rather less reactive substrates in order to direct chemical reaction sequences, from sequence-specific synthesis by the ribosome to polyketide synthases, where tethered molecules are passed from active site to active site in multi-enzyme complexes. Artificial molecular machines have been developed for tasks that include sequence-specific oligomer synthesis and the switching of product chirality, a photo-responsive host molecule has been described that is able to mechanically twist a bound molecular guest, and molecular fragments have been selectively transported in either direction between sites on a molecular platform through a ratchet mechanism. Here we detail an artificial molecular machine that moves a substrate between different activating sites to achieve different product outcomes from chemical synthesis. This molecular robot can be programmed to stereoselectively produce, in a sequential one-pot operation, an excess of any one of four possible diastereoisomers from the addition of a thiol and an alkene to an α,β-unsaturated aldehyde in a tandem reaction process. The stereodivergent synthesis includes diastereoisomers that cannot be selectively synthesized through conventional iminium-enamine organocatalysis. We anticipate that future generations of programmable molecular machines may have significant roles in chemical synthesis and molecular manufacturing.

Synthesis, characterization, spectroscopic properties and DFT study of a new pyridazinone family

Science.gov (United States)

Arrue, Lily; Rey, Marina; Rubilar-Hernandez, Carlos; Correa, Sebastian; Molins, Elies; Norambuena, Lorena; Zarate, Ximena; Schott, Eduardo

2017-11-01

Nitrogen compounds are widely investigated due to their pharmacological properties such as antihypertensive, antinociceptive, antibacterial, antifungal, analgesic, anticancer and inhibition activities and lately even as pesticide. In this context, we present the synthesis of new compounds: (E)-6-(3,4-dimethoxyphenyl)-3-(3-(3,4-dimethoxyphenyl)acryloyl)-1-(4-R-phenyl)- 5,6-dihydropyridazin-4(1H)-one (with R = sbnd H(1), -Cl(2), -Br(3), sbnd I(4) and sbnd COOH(5)) that was carried out by reaction of (1E, 6E)-1,7-bis(3,4-dimethoxyphenyl)hepta-1,6-diene-3,5-dione with a substituted phenylamine with general formula p-R-C6H4sbnd NH2 (R = sbnd H (1), sbnd Cl (2), -Br(3), sbnd I(4) and sbnd COOH(5)). This is the first synthesis report of a pyridazinone using as precursors a curcuminoid derivative and a diazonium salt formed in situ. All compounds were characterized by EA, FT-IR, UV-Vis, Emission,1H- and13C-NMR spectroscopy and the crystalline and molecular structure of 4 was solved by X-rays diffraction method. DFT and TD-DFT quantum chemical calculations were also employed to characterize the compounds and provide a rational explanation to the spectroscopic properties. To assess the biological activity of the systems, we focused on pesticide tests on compound 2, which showed an inhibitory effect in plant growth of Agrostis tenuis Higland.

Synthesis and characterization of photoswitchable fluorescent silica nanoparticles

NARCIS (Netherlands)

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

Hydrothermal synthesis and characterization of zirconia based catalysts

Science.gov (United States)

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.

Synthesis and Reactivity of Tripodal Complexes Containing Pendant Bases

Energy Technology Data Exchange (ETDEWEB)

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.

Synthesis and characterization of new ionic liquids; Sintese e caracterizacao de novos liquidos ionicos

Energy Technology Data Exchange (ETDEWEB)

Oliveira, L.M.C. de; Mattedi, S.; Boaventura, J.S., E-mail: luanaufrn@hotmail.co [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Escola Politecnica. Programa de Pos-Graduacao em Engenharia Quimica; Iglesias, M. [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Escola Politecnica. Programa de Pos-Graduacao em Engenharia Quimica; Universidad de Santiago de Compostela (Spain). Escuela Tecnica Superior de Ingenieria. Dept. de Ingenieria Quimica

2010-07-01

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)

Synthesis, characterization and electrospinning of corn cob cellulose-graft-polyacrylonitrile and their clay nanocomposites.

Science.gov (United States)

Kalaoğlu, Özlem I; Ünlü, Cüneyt H; Galioğlu Atıcı, Oya

2016-08-20

This study aims at evaluation of cellulose recovered from agricultural waste (corn cob) in terms of synthesis of graft copolymers, polymer/clay nanocomposites, and nanofibers. The copolymers and nanocomposites were synthesized in aqueous solution using Ce(4+) initiator. Conditions (concentrations of the components, reaction temperature, and period) were determined first for copolymer synthesis to obtain the highest conversion ratio. Then found parameters were used to synthesize nanocomposites adding clay mineral to reaction medium. Although there was a decrease in conversion in nanocomposites syntheses, thermal and rheologic measurements indicated enhancements compared to pristine copolymer. Obtained polymeric materials have been successfully electrospun into nanofibers and characterized. Average diameter of the nanofibers was about 650nm and was strongly influenced by NaMMT amount in the nanocomposite sample. Copyright © 2016 Elsevier Ltd. All rights reserved.

Synthesis and Characterization of New Polyamides from 1,2-Bis hydrazine Derivatives

International Nuclear Information System (INIS)

Salaha, A.; Abdel-Bary, E.M.; Kandilea, N.G.

2005-01-01

Preparation of polyamides having different chemical structures allows obtaining new materials with different mechanical and physical properties. The difference in the chemical structure depends mainly on the starting reactants used in condensation polymerization of polyamides. In this paper the synthesis of new polyamides based on the condensation polymerization of 1,2- Bis(3-carboxyacryloyl or carboxybenzoyl) hydrazine derivatives and various diamines has been described. The polymers obtained were characterized using spectroscopic and X-ray analysis. Besides thermal stability and electrical conductivity have been evaluated and correlated with the chemical structure of the polyamides obtained

Synthesis and characterization of platinum supported on alumina doped with cerium catalyst

International Nuclear Information System (INIS)

Yusof Abdullah; Abd Fatah Awang Mat; Mohd Ali Sufi; Sarimah Mahat; Razali Kassim; Nurhaslinda Abdullah.

1996-03-01

The synthesis and characterization of gamma-alumina doped with cerium as platinum support for the automobile exhaust catalyst are described. Platinum/alumina/ceria catalyst were prepared by impregnation of hexachloroplatinic acid and sintered at 500 degree Celsius to obtain metal dispersions of 1.0 wt%. Catalyst distribution inside the powder and the effects of the addition of cerium to alumina were analyzed by the scanning electron microscopy (SEM) and x-ray fluorescence spectroscopy (XRF). The results showed that the alumina - supported catalysts contained well dispersion of the noble metal

Synthesis of Cyclic Polymers and Characterization of Their Diffusive Motion in the Melt State at the Single Molecule Level

KAUST Repository

Habuchi, Satoshi

2016-09-26

We demonstrate a method for the synthesis of cyclic polymers and a protocol for characterizing their diffusive motion in a melt state at the single molecule level. An electrostatic self-assembly and covalent fixation (ESA-CF) process is used for the synthesis of the cyclic poly(tetrahydrofuran) (poly(THF)). The diffusive motion of individual cyclic polymer chains in a melt state is visualized using single molecule fluorescence imaging by incorporating a fluorophore unit in the cyclic chains. The diffusive motion of the chains is quantitatively characterized by means of a combination of mean-squared displacement (MSD) analysis and a cumulative distribution function (CDF) analysis. The cyclic polymer exhibits multiple-mode diffusion which is distinct from its linear counterpart. The results demonstrate that the diffusional heterogeneity of polymers that is often hidden behind ensemble averaging can be revealed by the efficient synthesis of the cyclic polymers using the ESA-CF process and the quantitative analysis of the diffusive motion at the single molecule level using the MSD and CDF analyses.

Carbazole Containing Copolymers: Synthesis, Characterization, and Applications in Reversible Holographic Recording

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Bénédicte Mailhot-Jensen

2010-01-01

Full Text Available Carbazolic copolymers have been developed to be used in reversible holographic recording. This paper describes a complete analysis, from synthesis of the material to its applications, together with the corresponding characterizations. The investigated materials were photosensitive copolymers obtained from carbazolylalkylmethacrylates (CEM and octylmethacrylate (OMA. A detailed investigation was undertaken involving infrared spectroscopy and NMR techniques, 1H, 13C, COSY, and HSQC, in order to establish the chemical structure and the composition of the copolymers. Holographic recording characteristics were investigated with one- and two-layer photothermoplastic carriers. The two-layer carrier contains separate photosensitive and thermoplastic layers and gives the best holographic response. The surface of microstructured samples has been characterized by atomic force microscopy analysis. It is shown that via a photothermoplastic recording process, it is possible to record and read holograms practically in real time (~3 s with a diffraction efficiency of 10% and a spatial resolution higher than 1000 mm−1.

Production and characterization of activated carbon prepared from safflower seed cake biochar and its ability to absorb reactive dyestuff

Energy Technology Data Exchange (ETDEWEB)

Angın, Dilek, E-mail: angin@sakarya.edu.tr [Department of Food Engineering, Faculty of Engineering, Sakarya University, Sakarya (Turkey); Köse, T. Ennil, E-mail: ennilb@ogu.edu.tr [Department of Chemical Engineering, Faculty of Engineering and Architecture, Eskisehir Osmangazi University, 26480 Meselik-Eskisehir (Turkey); Selengil, Uğur, E-mail: uselen@ogu.edu.tr [Department of Chemical Engineering, Faculty of Engineering and Architecture, Eskisehir Osmangazi University, 26480 Meselik-Eskisehir (Turkey)

2013-09-01

The use of activated carbon obtained from biochar for the removal of reactive dyestuff from aqueous solutions at various contact times, pHs and temperatures was investigated. The biochar was chemically modified with potassium hydroxide. The surface area and micropore volume of activated carbon was 1277 m{sup 2}/g and 0.4952 cm{sup 3}/g, respectively. The surface characterization of both biochar and activated carbon was undertaken using by Fourier transform infrared spectroscopy and scanning electron microscopy. The experimental data indicated that the adsorption isotherms are well described by the Dubinin–Radushkevich (DR) isotherm equation. The adsorption kinetics of reactive dyestuff obeys the pseudo second-order kinetic model. The thermodynamic parameters such as ΔG{sup o}, ΔH{sup o} and ΔS{sup o} were calculated to estimate the nature of adsorption. The activation energy of the system was calculated as 1.12 kJ/mol. According to these results, prepared activated carbon could be used as a low-cost adsorbent to compare with the commercial activated carbon for the removal reactive dyestuff from waste water.

Ion beams provided by small accelerators for material synthesis and characterization

Science.gov (United States)

Mackova, Anna; Havranek, Vladimir

2017-06-01

The compact, multipurpose electrostatic tandem accelerators are extensively used for production of ion beams with energies in the range from 400 keV to 24 MeV of almost all elements of the periodic system for the trace element analysis by means of nuclear analytical methods. The ion beams produced by small accelerators have a broad application, mainly for material characterization (Rutherford Back-Scattering spectrometry, Particle Induced X ray Emission analysis, Nuclear Reaction Analysis and Ion-Microprobe with 1 μm lateral resolution among others) and for high-energy implantation. Material research belongs to traditionally progressive fields of technology. Due to the continuous miniaturization, the underlying structures are far beyond the analytical limits of the most conventional methods. Ion Beam Analysis (IBA) techniques provide this possibility as they use probes of similar or much smaller dimensions (particles, radiation). Ion beams can be used for the synthesis of new progressive functional nanomaterials for optics, electronics and other applications. Ion beams are extensively used in studies of the fundamental energetic ion interaction with matter as well as in the novel nanostructure synthesis using ion beam irradiation in various amorphous and crystalline materials in order to get structures with extraordinary functional properties. IBA methods serve for investigation of materials coming from material research, industry, micro- and nano-technology, electronics, optics and laser technology, chemical, biological and environmental investigation in general. Main research directions in laboratories employing small accelerators are also the preparation and characterization of micro- and nano-structured materials which are of interest for basic and oriented research in material science, and various studies of biological, geological, environmental and cultural heritage artefacts are provided too.

Synthesis, characterization and application of nanozeolite NaX from Vietnamese kaolin

International Nuclear Information System (INIS)

Ngoc, Don Ta; Pham, Thanh Huyen; Hong Nguyen, Khanh Dieu

2013-01-01

This paper presents the results of synthesis of nanozeolite NaX from Vietnamese kaolin. Influence factors on the control of crystal sizes and application of synthesized materials as adsorbent for organic compound are discussed. The results show that there are several factors that influence the synthesis. When water content in gel increases, crystal size of NaX increases sharply. The increase of alkaline and silica contents increases the crystallinity and decreases the particle size of nano NaX, and the particle size reaches the minimum at Na 2 O/Al 2 O 3 = 5.0 and SiO 2 /Al 2 O 3 = 4.0. Crystal sizes formed at low crystallizing temperature are smaller than those formed at higher temperature. Ageing time and crystallizing time strongly influence the crystallinity and crystal size, which is related to the number of crystal seeds formed during ageing period, the growth of seed and the partial solubility of crystal at maximum formation. Nano NaX was characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer–Emmett–Teller (BET) adsorption, Fourier transform infrared (FTIR) and simultaneous thermogravimetry–differential scanning calorimetry (TG/DSC). At optimized synthesis conditions, nano NaX has surface area of 573 m 2 g −1 with external surface area of 92 m 2 g −1 , pore size distribution at 0.81 and 10.8 nm, average crystal size of 25 nm and thermal stability up to 789 °C. This material can adsorb cumene rapidly with high adsorption capacity and stability. (paper)

Synthesis and dosimetric characterization of LiF-MgF2, doped with Lu

International Nuclear Information System (INIS)

Gonzalez, Pedro R.; Nieto, Ana L.; Cruz-Zaragoza, Epifanio; Furetta, Claudio

2013-01-01

The results of the synthesis and characterization of dosimetric thermoluminescent material based on the composition LiF-MgF 2 1:1 (Z eff = 9.7) doped Lu 3+ ions, developed at the National Institute of Nuclear Research, Mexico are presented. The TL material synthesis was carried out using the technique of casting solid substances, preparations were made with dopant concentrations of 0.25, 0.83, 1.00 and 2.00 mol%, the 1 mol% resulted in increased sensitivity to radiation. Its brightness curve has the TL peak intensity at 330 deg C when irradiated to 1000 Gy, whereas when irradiated greater than 2500 Gy, occurs at 230 ° C, also has a peak of smaller maximum intensity at 140 ° C. Microstructural characterization of the obtained material was performed using the techniques of scanning electron microscopy and X-ray diffraction Kinetic parameters of the curves of brightness of the material is performed by the deconvolution method using the sequential quadratic programming algorithm, developed in the same institute. This new TL material complies fully with international standards to be used as dosimetry system in medical physics, research and industry, as its TL response (total integrated under the curve) to 60 Co gamma radiation, presents linearity between 1 and 5000 Gy , while the response of commercial TLD dosimeter-100 used as a reference, is only linear up to 10 Gy

Electrospun V2O5 composite fibers: Synthesis, characterization and ammonia sensing properties

International Nuclear Information System (INIS)

Modafferi, V.; Trocino, S.; Donato, A.; Panzera, G.; Neri, G.

2013-01-01

In the present work, vanadium oxide (V 2 O 5 ) fibers have been investigated for monitoring ammonia (NH 3 ) at ppb levels in air. A simple sol gel-based electrospinning process has been applied for the synthesis of vanadium oxide/polyvinyl acetate (PVAc) and vanadium oxide/polyvinylpyrrolidone (PVP) composite fibers. Composite fibers doped with platinum (Pt) have been also prepared. The pure and Pt-doped metal oxide phase has been subsequently obtained by removing the polymer binder at high temperature in air. The samples have been widely studied to characterize their morphological and microstructural properties by X-Ray Diffraction, Fourier Transform InfraRed spectroscopy, X-ray Photoelectron Spectroscopy, and Scanning Electron Microscopy investigations. The application of the produced fibers in highly sensitive ammonia resistive sensors has been demonstrated. The influence of the nature of polymer binder and platinum addition on the sensing performances of the V 2 O 5 fibers has been investigated and discussed.V 2 O 5 fibers produced by using PVP as a polymer binder have shown higher sensitivity toward ammonia at ppb concentrations than fibers obtained with PVAc. Pt-doped samples have shown a lower response compared to un-doped samples. - Highlights: • Synthesis of vanadium oxide composite fibers by electrospinning • Physical and chemical characterization of prepared samples • Investigation of the sensing properties to ppb concentrations of ammonia in air

Reactive oxygen species in the paraventricular nucleus of the hypothalamus alter sympathetic activity during metabolic syndrome.

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JOSIANE CAMPOS CRUZ

2015-12-01

Full Text Available The paraventricular nucleus of the hypothalamus (PVN contains heterogeneous populations of neurons involved in autonomic and neuroendocrine regulation. The PVN plays an important role in the sympathoexcitatory response to increasing circulating levels of angiotensin II (Ang-II, which activates AT1 receptors in the circumventricular organs (OCVs, mainly in the subfornical organ (SFO. Circulating Ang-II induces a de novo synthesis of Ang-II in SFO neurons projecting to pre-autonomic PVN neurons. Activation of AT1 receptors induces intracellular increases in reactive oxygen species (ROS, leading to increases in sympathetic nerve activity (SNA. Chronic sympathetic nerve activation promotes a series of metabolic disorders that characterizes the metabolic syndrome (MetS: dyslipidemia, hyperinsulinemia, glucose intolerance, hyperleptinemia and elevated plasma hormone levels, such as noradrenaline, glucocorticoids, leptin, insulin and Ang-II. This review will discuss the contribution of our laboratory and others regarding the sympathoexcitation caused by peripheral Ang-II-induced reactive oxygen species along the subfornical organ and paraventricular nucleus of the hypothalamus. We hypothesize that this mechanism could be involved in metabolic disorders underlying MetS.

Synthesis and thermoluminescent characterization of LiF doped with Ag; Sintesis y caracterizacion termoluminiscente de LiF dopado con Ag

Energy Technology Data Exchange (ETDEWEB)

Encarnacion, E. K.; Reyes, J.; Guerrero, Z. [Universidad Autonoma de Santo Domingo, Facultad de Ciencias, Ciudad Universitaria, Santo Domingo (Dominican Republic); Sosa, M. A.; Vallejo, M. A.; Rivera P, E., E-mail: emma.kee@gmail.com [Universidad de Guanajuato, Campus Leon, Division de Ciencias e Ingenierias, Loma del Bosque 103, Col. Lomas del Campestre, 37150 Leon, Guanajuato (Mexico)

2015-10-15

Full text: In this paper the synthesis and characterization of lithium fluoride (LiF) crystals pure and activated with silver (Ag) is reported. The synthesis was carried out by the method of co-precipitation; three samples were obtained one of pure LiF and two were activated with 0.02 and 0.04% of Ag. All samples were subjected to X-ray emission and the results were analyzed. The synthesized samples were characterized by X-ray diffraction, thermoluminescence and X-ray fluorescence. The XRD results show complete crystal structures. The radiation dosimetry responses are discussed. These are the first results of a research conducted at the Universidad Autonoma de Santo Domingo in collaboration with the Universidad de Guanajuato. (Author)

Synthesis and characterization of TiO2 nanoparticles by the method Pechini

International Nuclear Information System (INIS)

Zoccal, Joao Victor Marques; Arouca, Fabio de Oliveira; Goncalves, Jose Antonio Silveira

2009-01-01

In recent years, scientific research showed an increasing interest in the field of nanotechnology, resulting in several techniques for the production of nanoparticles, such as methods of chemical synthesis. Among the various existing methods, the Pechini method has been used to obtain nanoparticles of titanium dioxide (TiO 2 ). Thus, this work aims to synthesize and characterize nanoparticles of TiO 2 obtained by this method. The technique constitutes in the reaction between citric acid with titanium isopropoxide, resulting as the product the titanium citrate. With the addition of the ethylene glycol polymerization occurs, resulting in a polymeric resin. At the end of the process, the resin is calcined to remove organic matter, creating nanoparticles of TiO 2 . The resulting powders were characterized by thermogravimetric analysis (TGA) and thermal differential analysis (DTA), X-ray diffraction, absorption spectrophotometry in the infrared, method of adsorption nitrogen / helium (BET method) and scanning electron microscopy. The results obtained in the characterization techniques showed that the Pechini method is promising in obtaining nanosized TiO 2 . (author)

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

International Nuclear Information System (INIS)

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

2014-01-01

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

Synthesis and characterization of organic-inorganic hybrids formed between conducting polymers and crystalline antimonic acid

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Beleze Fábio A.

2001-01-01

Full Text Available In this paper we report the synthesis and characterization of novel organic-inorganic hybrid materials between the crystalline antimonic acid (CAA and two conductive polymers: polypyrrole and polyaniline. The hybrids were obtained by in situ oxidative polymerization of monomers by the Sb(V present in the pyrochlore-like CAA structure. The materials were characterized by infrared and Raman spectroscopy, X-ray diffraction, cyclic voltammetry, CHN elemental analysis and electronic paramagnetic resonance spectroscopy. The results showed that both polymers were formed in their oxidized form, with the CAA structure acting as a counter anion.

Synthesis, characterization and antimicrobial activity of important heterocyclic acrylic copolymers

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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.

Synthesis, characterization and wound healing imitation of Fe3O4 magnetic nanoparticle grafted by natural products

Science.gov (United States)

Pala, Sravan Kumar

This research focused on the study of the core-shelled magnetic nanomaterials derived from a colloidal chemistry. The goals are four-fold: (1) synthesis of Fe3O4MNMs using colloidal chemistry. The Fe 3O4 MNMs were then grafted with extracts derived from natural products, namely Olecraceavar italica (broccoli), Boletus edulis (mushroom)and Solanum lycopersicum (tomato);(2)characterization of natural products by chromatography and mass spectrometry;(3) characterization of MNMs to determine their crystallinity, morphological and elemental composition by the state-of-the-art instruments; and (4) biological evaluation using Gram-negative and Gram-positive bacteria. The approach provides advantages to precisely control the composition and homogeneity. The second advantage of the colloidal chemistry is its user friendliness and feasibility. Due to the nature of the natural products, the compatibility of MNM is anticipated to be enhanced.In this chapter, the nanomaterials will be discussed from four perspectives,§1.1 Nanotechnology (§1.1), §1.2 Synthesis of nanomaterials; §1.3 The natural product extract,; §1.4 Characterization of nanomaterials; and §1.5Biological application of nanomaterials.Fig. 1 summarized the overarching goals of this study.

Bio-assisted synthesis and characterization of nanostructured bismuth (III) sulphide using Clostridium acetobutylicum

International Nuclear Information System (INIS)

Kamaraj, Sathish Kumar; Venkatachalam, Ganesh; Arumugam, Palaniappan; Berchmans, Sheela

2014-01-01

Nanostructured bismuth (III) sulphide is synthesized at room temperature using a hydrogen sulphide producing microorganism namely Clostridium acetobutylicum. On contrary to chemical routes involving both the high and room temperature methods, the present experimental procedure involves a bio-assisted approach. This method is free from the usage of toxic and hazardous chemicals making it an environment friendly route. The synthesized bismuth sulphide is characterized using transmission electron microscope (TEM), powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and cyclic voltammetry (CV). From our experiments we find that bismuth sulphide produced using this bio-assisted approach exhibits a hexagonal shaped plate-like structures and is stabilized by the extracellular proteins present in the culture medium. - Graphical abstract: A green chemistry approach towards the synthesis of bismuth (III) sulphide nanostructures at room temperature using a hydrogen sulphide producing microorganism namely, Clostridium acetobutylicum is demonstrated. - Highlights: • Environmentally benign (greener) route towards synthesis of Bi 2 S 3 nanostructures. • Bio-assisted synthesis of Bi 2 S 3 at room temperature using Clostridium acetobutylicum. • Extracellular proteins in H 2 S producing microorganism as stabilizer for Bi 2 S 3 NPs. • Hexagonal platelets of Bi 2 S 3 possessing an orthorhombic crystalline structure

Novel synthesis and characterization of a collagen-based biopolymer initiated by hydroxyapatite nanoparticles.

Science.gov (United States)

Bhuiyan, D; Jablonsky, M J; Kolesov, I; Middleton, J; Wick, T M; Tannenbaum, R

2015-03-01

In this study, we developed a novel synthesis method to create a complex collagen-based biopolymer that promises to possess the necessary material properties for a bone graft substitute. The synthesis was carried out in several steps. In the first step, a ring-opening polymerization reaction initiated by hydroxyapatite nanoparticles was used to polymerize d,l-lactide and glycolide monomers to form poly(lactide-co-glycolide) co-polymer. In the second step, the polymerization product was coupled with succinic anhydride, and subsequently was reacted with N-hydroxysuccinimide in the presence of dicyclohexylcarbodiimide as the cross-linking agent, in order to activate the co-polymer for collagen attachment. In the third and final step, the activated co-polymer was attached to calf skin collagen type I, in hydrochloric acid/phosphate buffer solution and the precipitated co-polymer with attached collagen was isolated. The synthesis was monitored by proton nuclear magnetic resonance, infrared and Raman spectroscopies, and the products after each step were characterized by thermal and mechanical analysis. Calculations of the relative amounts of the various components, coupled with initial dynamic mechanical analysis testing of the resulting biopolymer, afforded a preliminary assessment of the structure of the complex biomaterial formed by this novel polymerization process. Copyright © 2015. Published by Elsevier Ltd.

‘Umpolung’ Reactivity in Semiaqueous Amide and Peptide Synthesis

Science.gov (United States)

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

The iodine reactivity

International Nuclear Information System (INIS)

2003-01-01

The iodine is an important element because it has long life isotopes (such as iodine 129) and a great mobility in natural media. Iodine presents a complex chemistry because of its volatility and its strong redox reactivity. The S.E.C.R. works to better understand the reactivity of this element in different natural, industrial or biological environments. It plays a part in thermochemical sites as a possible way of hydrogen formation. This seminar gives some aspects relative to the chemical reactivity of iodine, since its thermochemistry in the I/S cycles to produce hydrogen to its reactivity in the natural medium and its potential radiological impact. This document includes 4 presentations transparencies) dealing with: the 129 I cycle rejected in the low radioactive gaseous and liquid effluents of the La Hague reprocessing plant (C. Frechou); a bibliographic review of iodine retention in soils (F. Bazer-Bachi); the hydrogen production and the iodine/sulfur thermochemical cycle (role of iodine in the process); and the direct characterization by electro-spray ionization mass spectroscopy of iodine fixation by fulvic acids (P. Reiller, B. Amekraz, C. Moulin, V. Moulin)

Selective synthesis and characterization of chlorins as sensitizers for photodynamic therapy

Science.gov (United States)

Montforts, Franz-Peter; Kusch, Dirk; Hoper, Frank; Braun, Stefan; Gerlach, Benjamin; Brauer, Hans-Dieter; Schermann, Guido; Moser, Joerg G.

1996-04-01

Chlorin type sensitizers have ideal photophysical properties for an application in PDT. The basic chlorin framework of these sensitizers has to be modified by attachment of lipophilic and hydrophilic residues to achieve a good cell uptake and tumor enrichment. In the present study we describe the selective synthesis of amphiphilic chlorins starting from the readily accessible red blood pigment heme. The photophysical properties of the well defined synthetic chlorins are characterized by photophysical investigations. The kinetic of cell uptake, the localization in the cell and the photodynamic behavior of the amphiphilic sensitizers are demonstrated by incubation of A 375 cancer cell lines with structurally different chlorins.

Synthesis and characterization of semi-IPNs based on PVP and PLLA

International Nuclear Information System (INIS)

Camilo, A.P.R.; Mano, V.; Felisberti, M.I.

2010-01-01

The specific interest in the synthesis of semi-IPNs based on PLLA and PVP homopolymers due to the fact these are biodegradable and biocompatible, which allows us to infer applications in the medical field as sutures, implants, matrices for controlled release of drugs etc. The objective was to prepare a multicomponent material amphiphile in the form of semi-interpenetrating polymer networks, based on poly (L-lactide), PLLA, hydrophobic homopolymer, and poly (vinylpyrrolidone), PVP, hydrophilic component. The preparation of semi-IPN combined the polymerization and crosslinking of N-vinylpyrrolidone in the presence of poly (L-lactide). The products were characterized by spectroscopic and thermal methods. (author)

Synthesis and processing of composites by reactive metal penetration

Energy Technology Data Exchange (ETDEWEB)

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.

Reduced Reactivity of Amines against Nucleophilic Substitution via Reversible Reaction with Carbon Dioxide

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Fiaz S. Mohammed

2015-12-01

Full Text Available The reversible reaction of carbon dioxide (CO2 with primary amines to form alkyl-ammonium carbamates is demonstrated in this work to reduce amine reactivity against nucleophilic substitution reactions with benzophenone and phenyl isocyanate. The reversible formation of carbamates has been recently exploited for a number of unique applications including the formation of reversible ionic liquids and surfactants. For these applications, reduced reactivity of the carbamate is imperative, particularly for applications in reactions and separations. In this work, carbamate formation resulted in a 67% reduction in yield for urea synthesis and 55% reduction for imine synthesis. Furthermore, the amine reactivity can be recovered upon reversal of the carbamate reaction, demonstrating reversibility. The strong nucleophilic properties of amines often require protection/de-protection schemes during bi-functional coupling reactions. This typically requires three separate reaction steps to achieve a single transformation, which is the motivation behind Green Chemistry Principle #8: Reduce Derivatives. Based upon the reduced reactivity, there is potential to employ the reversible carbamate reaction as an alternative method for amine protection in the presence of competing reactions. For the context of this work, CO2 is envisioned as a green protecting agent to suppress formation of n-phenyl benzophenoneimine and various n-phenyl–n-alky ureas.

Exploring the Fundamentals of Microreactor Technology with Multidisciplinary Lab Experiments Combining the Synthesis and Characterization of Inorganic Nanoparticles

Science.gov (United States)

Emmanuel, Noemie; Emonds-Alt, Gauthier; Lismont, Marjorie; Eppe, Gauthier; Monbaliu, Jean-Christophe M.

2017-01-01

Multidisciplinary lab experiments combining microfluidics, nanoparticle synthesis, and characterization are presented. These experiments rely on the implementation of affordable yet efficient microfluidic setups based on perfluoroalkoxyalkane (PFA) capillary coils and standard HPLC connectors in upper undergraduate chemistry laboratories.…

A Model-Based Methodology for Integrated Design and Operation of Reactive Distillation Processes

DEFF Research Database (Denmark)

Mansouri, Seyed Soheil; Sales-Cruz, Mauricio; Huusom, Jakob Kjøbsted

2015-01-01

and resolved. A new approach isto tackle process intensification and controllability issues in an integrated manner, in the early stages of process design. This integrated and simultaneous synthesis approach provides optimal operation and moreefficient control of complex intensified systems that suffice...... calculation of reactive bubble points. For an energy-efficient design, the driving-forc eapproach (to determine the optimal feed location) for a reactive system has been employed. For both thereactive McCabe-Thiele and driving force method, vapor-liquid equilibrium data are based on elements. Thereactive...... system of compounds (methanol, isobutene and MTBE) to a binary system ofelements (elements A and B). For a binary element system, a simple reactive McCabe-Thiele-type method (to determine the number of reactive stages) has been used. The reactive equilibrium curve is constructed through sequential...

Synthesis, characterization and applications of graphene architectures

Science.gov (United States)

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

SYNTHESIS AND CHARACTERIZATION OF NEW STABILIZERS WITH OPTIMAL MOLECULAR WEIGHT

Institute of Scientific and Technical Information of China (English)

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.``

Synthesis and Characterization of High-Dielectric-Constant Nanographite-Polyurethane Composite

Science.gov (United States)

Mishra, Praveen; Bhat, Badekai Ramachandra; Bhattacharya, B.; Mehra, R. M.

2018-05-01

In the face of ever-growing demand for capacitors and energy storage devices, development of high-dielectric-constant materials is of paramount importance. Among various dielectric materials available, polymer dielectrics are preferred for their good processability. We report herein synthesis and characterization of nanographite-polyurethane composite with high dielectric constant. Nanographite showed good dispersibility in the polyurethane matrix. The thermosetting nature of polyurethane gives the composite the ability to withstand higher temperature without melting. The resultant composite was studied for its dielectric constant (ɛ) as a function of frequency. The composite exhibited logarithmic variation of ɛ from 3000 at 100 Hz to 225 at 60 kHz. The material also exhibited stable dissipation factor (tan δ) across the applied frequencies, suggesting its ability to resist current leakage.

Photodegradation of Reactive Golden Yellow R Dye Catalyzed by Effective Titania (TiO2)

International Nuclear Information System (INIS)

Bedurus, E.A.; Marinah Mohd Ariffin; Mohd Hasmizam Razali

2015-01-01

In the present research, Microwave Assisted Synthesis (MAS) method was applied to synthesize titania (TiO 2 ) at 150 degree Celsius in a range of 2-6 hours heating time. Each prepared TiO 2 were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and nitrogen gas (N 2 ) sorption analysis (Brunaeur-Emmett-Teller (BET) and Barrett-Joyner-Halenda (BJH) calculation) techniques. The TiO 2 prepared by MAS 150 degree Celsius (4 hours) has emerged with the highest photo catalytic activity. Within 4 hours, the TiO 2 managed to catalyze the degradation of Reactive Golden Yellow R dye up to 98.51 %. This is because of the TiO 2 possessed high crystallinity of anatase phase, small crystallite size and high pore volume compared to other prepared TiO 2 . (author)

Synthesis, stability range and characterization of Pr2Cu2O5

Science.gov (United States)

Fernández-Sanjulián, Javier; Morán, Emilio; Ángel Alario-Franco, Miguel

2010-03-01

A novel Pr2Cu2O5 phase has been prepared under high-pressure and high-temperature conditions (P ∼6 GPa and T ∼1673 K) in a Belt-type apparatus and characterized by X-ray diffraction and electron microscopy. The crystal structure appears to be an orthorhombic "oxygen-deficient perovskite" (M.T. Anderson, J.T. Vaughey, and K.R. Poeppelmeier, Structural similarities among oxygen-deficient perovskites, Chem. Mater. 5 (1993), pp. 151-165) isostructural with La2Cu2O5 (J.F. Bringley, B.A. Scott, S.J. La Placa, R.F. Boheme, T.M. Shaw, M.W. McElfresh, S.S. Trail, and D.E. Cox, Synthesis of the defect perovskite series LaCuO 3-δ with copper valence varying from 2+to 3+, Nature 347 (1990), pp. 263-265) and Nd2Cu2O5 (B.-H. Chen, D. Walker, E. Suard, B.A. Scott, B. Mercey, M. Hervieu, and B. Raveau, High pressure synthesis of NdCuO3-δ perovskites (0≤δ≤0.5). Inorg. Chem. 34 (1995), pp. 2077-2083).

Synthesis and characterization of bulk Cu2ZnSnX4 (X: S, Se) via thermodynamically supported mechano-chemical process

International Nuclear Information System (INIS)

Pareek, Devendra; Balasubramaniam, K.R.; Sharma, Pratibha

2015-01-01

Materials with the general formula, Cu 2 ZnSnX 4 (CZTX; X: Group 16 elements), with X being S/Se, have been receiving considerable attention due to their utility as an absorber layer in solar photovoltaics (PV). This paper reports on the synthesis of CZTSe and CZTS nanocrystalline powders at low temperatures, starting from elemental metal and chalcogen powders, via the low cost, scalable technique of ball milling. The prepared samples were well characterized using the different characterization tools. XRD, Raman, SEM and TEM studies confirm the formation of single-phase, stoichiometric, nano-crystalline kesterite CZTS and CZTSe powders. The low temperature phase selection of the complex quaternary compound in this system is seen as a direct consequence of the thermodynamic facilitation, coupled with the capability of mechano-chemical synthesis to aid in overcoming kinetic constraints. The optical bandgap of the various samples of CZTS was observed in the range of 1.4–1.6 eV and corresponding values for CZTSe was observed to be in the range of 1.08–1.18 eV. Our work provides a pathway for developing cheap, scalable, and ink-based techniques for low cost solar PV. - Graphical abstract: Display Omitted - Highlights: • A scalable route for synthesis of near phase pure CZTS/Se nano-crystals has been demonstrated. • Stoichiometric CZTS and CZTSe were synthesized via mechano-chemical synthesis route. • Synthesis at near room temperature is supported by thermodynamic calculations

Synthesis and characterization of poly iodine anilines by plasma

International Nuclear Information System (INIS)

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

Synthesis of Fluoroolefins via Julia-Kocienski Olefination

OpenAIRE

Zajc, Barbara; Kumar, Rakesh

2010-01-01

The Julia-Kocienski olefination provides a versatile platform for the synthesis of fluorovinyl compounds. This review describes our efforts as well as those of others in the synthesis of various fluorinated aryl and heteroaryl sulfones and their utility as olefination reagents for the modular assembly of fluoroalkenes. Where data is available, the influence of the fluorine atom on the reactivity of the olefination reagents and the stereochemical outcome of the olefination are described.

Synthesis of Fluoroolefins via Julia-Kocienski Olefination.

Science.gov (United States)

Zajc, Barbara; Kumar, Rakesh

2010-01-01

The Julia-Kocienski olefination provides a versatile platform for the synthesis of fluorovinyl compounds. This review describes our efforts as well as those of others in the synthesis of various fluorinated aryl and heteroaryl sulfones and their utility as olefination reagents for the modular assembly of fluoroalkenes. Where data is available, the influence of the fluorine atom on the reactivity of the olefination reagents and the stereochemical outcome of the olefination are described.

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

NARCIS (Netherlands)

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

Synthesis and characterization of novel nanothermometers

Energy Technology Data Exchange (ETDEWEB)

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.

Synthesis, characterization, and application of novel biodegradable self-assembled 2-(N-phthalimido) ethyl-palmitate nanoparticles for cancer therapy

Science.gov (United States)

Kasoju, Naresh; Bora, Debajeet K.; Bhonde, Ramesh R.; Bora, Utpal

2010-03-01

We report the synthesis of novel biodegradable nanoparticles (NPs) which can kill the cancer cells without any additional drug loading. The NP was a self-assembled form of a phthalimide based conjugate, in which the phthalimide moiety was responsible for the anticancer activity. We describe the synthesis of a novel 2-(N-phthalimido) ethyl palmitate (PHEP-Pal) conjugate and subsequent preparation of NPs by a simple self assembly process. The successful synthesis of conjugate was confirmed by various characterization studies including nuclear magnetic resonance spectroscope, Fourier transform infrared spectroscope, TOF-liquid chromatography mass spectroscope, differential scanning calorimetry, and X-ray diffraction unit. The synthesis, shape, size, and size distribution of PHEP-Pal NPs were determined by transmission electron microscope, atomic force microscope, and dynamic light scattering technique. Finally, cell culture studies using A549 and HeLa cells were done to evaluate the anticancer effect of PHEP-Pal NPs, which demonstrated the potency of these NPs for use in cancer chemotherapy.

Synthesis and characterization of nano hydroxyapatite using reverse micro emulsions as nano reactors

International Nuclear Information System (INIS)

Amin, S.; Siddique, T.

2015-01-01

In the present work reverse micro emulsion has been employed as nano reactors to synthesize nano crystalline Hydroxyapatite (HA). Two precursors; calcium and phosphate with different counter ions of each were used for the synthesis of HA at two different temperatures. To maintain the emulsified nano reactor, cyclohexane, TX-100 and 1-butanol including phosphate precursor was the continuous phase while aqueous Ca precursor solution was taken as the dispersed phase. Nano crystalline particles thus produced were evaluated on the basis of synthesis route, counter ions and temperature. It has been shown that emulsified nano reactors control the morphology, particle size and minimize phase transformation of HA. Characterizations of nano powder of HA are carried out using x-ray diffraction (XRD), Fourier transform infra-red spectroscopy (FTIR), and scanning electron microscopy (SEM). HA crystallite size was found to be in the range of 20-25 nm whereas the morphology of nano particles changed from spheres to rods. (author)

Synthesis and Photophysical Characterizations of Thermal -Stable Naphthalene Benzimidazoles

OpenAIRE

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 ...

Borylnitrenes: electrophilic reactive intermediates with high reactivity towards C-H bonds.

Science.gov (United States)

Bettinger, Holger F; Filthaus, Matthias

2010-12-21

Borylnitrenes (catBN 3a and pinBN 3b; cat = catecholato, pin = pinacolato) are reactive intermediates that show high tendency towards insertion into the C-H bonds of unactivated hydrocarbons. The present article summarizes the matrix isolation investigations that were aimed at identifying, characterizing and investigating the chemical behaviour of 3a by spectroscopic means, and of the experiments in solution and in the gas phase that were performed with 3b. Comparison with the reactivity reported for difluorovinylidene 1a in solid argon indicates that 3a shows by and large similar reactivity, but only after photochemical excitation. The derivative 3b inserts into the C-H bonds of hydrocarbon solvents in high yields and thus allows the formation of primary amines, secondary amines, or amides from "unreactive" hydrocarbons. It can also be used for generation of methylamine or methylamide from methane in the gas phase at room temperature. Remaining challenges in the chemistry of borylnitrenes are briefly summarized.

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

International Nuclear Information System (INIS)

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

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

Science.gov (United States)

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

Synthesis and characterization of a new complex binuclear of binuclear of Pd(II) containing the antibiotic oxy tetracycline

International Nuclear Information System (INIS)

Guerra, Wendell; Fontes, Ana Paula Soares; Pereira-Maia, Elene Cristina

2010-01-01

This article reports the synthesis and characterization of a new binuclear complex of palladium (II) containing the antibiotic oxytetracycline. The complex was characterized by the usual techniques of analysis. With respect to sites of coordination, the IR spectral data suggests the involvement the oxygen of the amide group and the oxygen of the neighbor hydroxyl group at ring A and to the carbonyl oxygen at C11 and the hydroxyl group at C12. (author)

“Synthesis-on” and “synthesis-off” modes of carbon arc operation during synthesis of carbon nanotubes

International Nuclear Information System (INIS)

Yatom, Shurik; Selinsky, Rachel S.

2017-01-01

Arc discharge synthesis of single-walled carbon nanotubes (SWCNTs) remains largely uncontrollable, due to incomplete understanding of the synthetic process itself. Here, we show that synthesis of SWCNTs by a carbon arc may not constitute a single continuous process, but may instead consist of two distinct modes. One of these, a “synthesis-on” mode, produces the majority of the nanomaterials. During the synthesis-on mode, proportionally more carbon nanotubes are collected than in another mode, a “synthesis-off” mode. Both synthesis-on and synthesis-off modes for a typical arc configuration, employing a hollow anode filled with a mixture of powdered metal catalyst and graphite, were characterized by using in situ electrical, imaging, and spectroscopic diagnostics, along with ex situ imaging and spectroscopy. The synthesis-on mode duration is rare compared to the total arc run-time, helping to explain the poor selectivity found in the final collected products, a known inadequacy of arc synthesis. Finally, the rarity of the synthesis on mode occurence may be due to the synthesis off mode being more favorable energetically.

Incorporation of the zosteric sodium salt in silica nanocapsules: synthesis and characterization of new fillers for antifouling coatings

Science.gov (United States)

Ruggiero, Ludovica; Crociani, Laura; Zendri, Elisabetta; El Habra, Naida; Guerriero, Paolo

2018-05-01

In the last decade many commercial biocides were gradually banned for toxicity. This work reports, for the first time, the synthesis and characterization of silica nanocontainers loaded with a natural product antifoulant (NPA), the zosteric sodium salt which is a non-commercial and environmentally friendly product with natural origin. The synthesis approach is a single step dynamic self-assembly with tetraethoxysilane (TEOS) as silica precursor. Unlike conventional mesoporous silica nanoparticles, the structure of these silica nanocontainers provides loading capacity and allows prolonged release of biocide species. The obtained nanocapsules have been characterized morphologically by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The encapsulation was checked by FTIR ATR spectroscopy and thermogravimetric analyses. The results of the release studies show the great potential of the here presented newly developed nanofillers in all applications where a controlled release of non-toxic and environmentally friendly biocides is required.

Synthesis and characterization of composites HoMn_1_-_x(Ni,Co)_xO_3

International Nuclear Information System (INIS)

Santos, Cassio Morilla dos

2011-01-01

In this work was accomplished the synthesis process and structural and magnetic characterization of HoMn_1_-_X(Ni,Co)_XO_3 compounds of perovskite structure. The samples synthesis were performed through modified polymeric precursor method. After synthesis and solvent removal, the polymer resin formed was treated at 350 deg C/4h for organic constituents removal, followed by heating treatment at 500 deg C/4h and 900 deg C/20h to obtain the crystalline phase. For structural characterization, it was used D10B-XPD beam line of Laboratorio Nacional de Luz Sincrotron (LNLS), where X-rays wavelengths below cobalt, manganese and nickel absorption edge, were used. The formation of HoNi_0_._5_0Mn_0_._5_0O_3, HoCo_0_._5_0Mn_0_._5_0O_3 and HoNi_0_._2_5Co_0_._2_5Mn_0_._5_0O_3 phases were observed by X-ray diffraction technique. By Rietveld refinement method for sample HoNi_0_._2_5Co_0_._2_5Mn_0_._5_0O_3, it was determined that cobalt and nickel had similar occupations at the top and bottom of unit cell, while the manganese preferentially occupied plan 002. The magnetic response of samples was studied through magnetization curves according to the temperature function and the applied magnetic field. The ZFC curves showed a paramagnetic response associated to holmium magnetic moment, and ferromagnetism, antiferromagnetism and ferrimagnetism coexistence, due to sublattices formed by transition metals. The FC curves evidenced the spin reversal phenomenon, associated to the interaction between the sublattice formed by transition metals with sublattices formed by rare-earth, considering a mechanism of antiferromagnetic exchange interaction. (author)

Synthesis and characterization of ferrous phosphate (vivianite) and its behavior in aqueous media

International Nuclear Information System (INIS)

Diaz F, J.C.

2003-01-01

The synthesis and characterization of materials that can be useful in Environmental Chemistry is very important because their characteristics are exposed and its behavior in chemical phenomena as the sorption in aqueous media is understand to use it in the human being benefit. With the object of using, in a future, the octa hydrated ferrous phosphate (vivianite) as a potential candidate for matrix confinement in contention walls for the storage of radioactive waste of long half life, it was synthesized and it characterized physico chemically and their properties of surface of this compound were evaluated. Presently work was carried out the synthesis and structural characterization of the iron phosphate II by infrared spectroscopy with having Fourier transform, high vacuum scanning electron microscopy, X-ray diffraction, thermal gravimetric analysis, the BET multipoint surface area and Moessbauer spectroscopy; as well as, the determination between aqueous media of the isoelectric point and the density of sites of surface of the compound. The octa hydrated ferrous phosphate was obtained pure. The results indicate that the product corresponds to the prospective mineral, the vivianite. The thermal gravimetric analysis demonstrated that the ferrous phosphate is a stable salt after the lost of water. The isoelectric point is since an important parameter because allows to know the behavior of the surface of the material in aqueous systems, in this case the isoelectric point, of the octa hydrated ferrous phosphate, in distilled water is of pH 4.20 and in solution of potassium nitrate 0.5 M is of pH = 3.75. This indicates that the material has an amphoteric surface depending on the pH. On the other hand, the density of active sites of surface obtained by titrations acid-base is of 20 sites by nm 2 . (Author)

A roadmap for OH reactivity research

Science.gov (United States)

Williams, Jonathan; Brune, William

2015-04-01

A fundamental property of the atmosphere is the frequency of gas-phase reactions with the OH radical, the atmosphere's primary oxidizing agent. This reaction frequency is called the OH reactivity and is the inverse the lifetime of the OH radical itself, which varies from a few seconds in the clean upper troposphere to below 10 ms in forests and polluted city environments. Ever since the discovery of the OH radical's importance to tropospheric chemistry, the characterization of its overall loss rate (OH reactivity) has remained a key question. At first, this property was assessed by summing the reactivity contributions of individually measured compounds; however, as improving analytical technology revealed ever more reactive species in ambient air, it became clear that this approach could provide only a lower limit. Approximately 15 years ago, the direct measurement of total OH reactivity was conceived independently by two groups. The first publications demonstrated direct OH reactivity measurements in the laboratory (Calpini et al., 1999) based on LIDAR and in the ambient air (Kovacs and Brune, 2001) based on in situ laser induced fluorescence detection of OH.

Synthesis and characterization of nanostructured titanium carbide for fuel cell applications

Energy Technology Data Exchange (ETDEWEB)

Singh, Paviter; Singh, Harwinder; Singh, Bikramjeet; Kaur, Manpreet; Kaur, Gurpreet; Kumar, Akshay, E-mail: akshaykumar.tiet@gmail.com [Advanced Functional Material Laboratory, Department of Nanotechnology,, Sri Guru Granth Sahib World University, Fatehgarh Sahib-140 406 Punjab (India); Kumar, Manjeet [Department of Materials Engineering, Defense Institute of Advanced Technology (DU), Pune-411 025 (India); Bala, Rajni [Department of Mathematics Punjabi University Patiala-147 002 Punjab (India)

2016-04-13

Titanium carbide (TiC) nanoparticles have been successfully synthesized by carbo-thermic reaction of titanium and acetone at 800 °C. This method is relatively low temperature synthesis route. It can be used for large scale production of TiC. The synthesized nanoparticles have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and differential thermal analyzer (DTA) techniques. XRD analysis confirmed the formation of single phase TiC. XRD analysis confirmed that the particles are spherical in shape with an average particle size of 13 nm. DTA analysis shows that the phase is stable upto 900 °C and the material can be used for high temperature applications.

Synthesis and Characterization of Calcium Phosphate Powders for Biomedical Applications by Plasma Spray Coating

OpenAIRE

Sasidharan Pillai, Rahul

2015-01-01

This PhD work mainly focus on the synthesis and characterization of calcium phosphate powders for plasma spray coating. The preparation of high temperature phase stabilized βTCP and HA/βTCP powders for plasma spray coating applications has been the topic of investigation. Nowadays plasma sprayed coatings are widely used for biomedical applications especially in the dental and orthopaedic implantation field. Previously Ti based alloys were widely used for the orthopaedic and dental implant ap...

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

Directory of Open Access Journals (Sweden)

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.

Modified Polyacrylic Acid-Zinc Composites: Synthesis, Characterization and Biological Activity

Directory of Open Access Journals (Sweden)

Mohammed Rafi Shaik

2016-02-01

Full Text Available Polyacrylic acid (PAA is an important industrial chemical, which has been extensively applied in various fields, including for several biomedical purposes. In this study, we report the synthesis and modification of this polymer with various phenol imides, such as succinimide, phthalimide and 1,8-naphthalimide. The as-synthesized derivatives were used to prepare polymer metal composites by the reaction with Zn+2. These composites were characterized by using various techniques, including NMR, FT-IR, TGA, SEM and DSC. The as-prepared PAA-based composites were further evaluated for their anti-microbial properties against various pathogens, which include both Gram-positive and Gram-negative bacteria and different fungal strains. The synthesized composites have displayed considerable biocidal properties, ranging from mild to moderate activities against different strains tested.

CsPb2Br5 Single Crystals: Synthesis and Characterization

KAUST Repository

Dursun, Ibrahim

2017-08-02

CsPb2Br5 is a ternary halogen-plumbate material with close characteristics to well-reported halide perovskites. Due to its unconventional two-dimensional structure, CsPb2Br5 is being looked at broadly for potential applications in optoelectronics. CsPb2Br5 investigations are currently limited to nanostructures and powder forms of the material, which present unclear and conflicting optical properties. In this study, we present the synthesis and characterization of CsPb2Br5 bulk single crystals, which enabled us to finally clarify the material\\'s optical features. Our CsPb2Br5 crystal has a two-dimensional structure with Pb2Br5- layers spaced by Cs+ cations, and exhibits a ~3.1 eV indirect bandgap with no emission in the visible spectrum.

Synthesis and characterization of acrylate copolymer containing fluorescein functional group

International Nuclear Information System (INIS)

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

Synthesis, characterization and antibacterial property of ZnO:Mg nanoparticles

Science.gov (United States)

Kompany, A.; Madahi, P.; Shahtahmasbi, N.; Mashreghi, M.

2012-09-01

Sol-gel method was successfully used for the synthesis of ZnO nanoparticles (NPs) doped with different concentrations of Mg and the structural, optical and antibacterial properties of the nanoparticles were studied. The synthesized ZnO:Mg powders were characterized using x-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transformation Infrared (FTIR) and UV-Vis spectroscopy. It was revealed that the samples have hexagonal Wurtzite structure, and the phase segregation takes place for 15% Mg content. TEM images show that the average size of the particles is about 50 nm. Also, the antibacterial activities of the nanoparticles were tested against Escherichia coli (Gram negative) cultures. ZnO:Mg nanofluid showed good antibacterial activity which increases with the increase of NPs concentration, and decreases slightly with the amount of Mg.

Green synthesis, characterization and antibacterial efficacy of palladium nanoparticles synthesized using Filicium decipiens leaf extract

Science.gov (United States)

Sharmila, G.; Farzana Fathima, M.; Haries, S.; Geetha, S.; Manoj Kumar, N.; Muthukumaran, C.

2017-06-01

Synthesis of metal nanoparticles through green chemistry route is an emerging eco-friendly approach in the present days. An eco-friendly, biogenic synthesis of palladium nanoparticles (PdNPs) using Filicium decipiens leaf extract was reported in the present study. The synthesized PdNPs were characterized by UV-visible spectroscopy, Transmission electron microscopy (TEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The PdNPs formation was confirmed by UV-visible spectrophotometer and spherical shaped PdNPs with size range of 2-22 nm was observed in TEM analysis. Energy dispersive X-ray spectroscopy (EDS) analysis confirmed the presence of palladium in the synthesized nanoparticles. The crystalline nature of PdNPs was confirmed by XRD pattern and compared with the standard. The phytochemicals and proteins were identified by their functional groups in FT-IR spectrum and revealed the amide, amine groups present in F. decipiens may have involved in the bio-reduction reaction for PdNPs synthesis. Prepared PdNPs showed potential antibacterial activity against both Gram-positive and Gram-negative bacteria. F. decipiens leaf extract based PdNPs showed high bactericidal activity against Escherichia coli, Pseudomonas aeruginosa as compared to Staphylococcus aureus and Bacillus subtilis Results showed that phytochemicals rich F. decipiens leaf extract may be utilized as an effective non-toxic reducing agent for PdNPs synthesis and prepared PdNPs may useful in biomedical applications.

Ultrafiltration membranes from waste polyethylene terephthalate and additives: synthesis and characterization

Directory of Open Access Journals (Sweden)

Smitha Rajesh

2014-01-01

Full Text Available The synthesis and characterization of asymmetric ultrafiltration membranes from recycled polyethylene terephthalate (PET and polyvinylpyrrolidone (PVP is reported. PET is currently used in many applications, including the manufacture of bottles and tableware. Monomer extraction from waste PET is expensive, and this process has not yet been successfully demonstrated on a viable scale. Hence, any method to recycle or regenerate PET once it has been used is of significant importance from scientific and environmental research viewpoints. Such a process would be a green alternative due to reduced raw monomer consumption and the additional benefit of reduced manufacturing costs. The membranes described here were prepared by a phase-inversion process, which involved casting a solution containing PET, m-cresol as solvent, and polyethylene glycol (PEG of different molecular weights as additives. The membranes were characterized in terms of pure water permeability (PWP, molecular weight cut-off (MWCO, and flux and membrane morphology. The results show that the addition of PEG with high molecular weights leads to membranes with higher PWP. The presence of additives affects surface roughness and membrane morphology.

REDUCTIVE DEHALOGENATION OF HALOMETHANES IN IRON- AND SULFATE-REDUCING SEDIMENTS. 1. REACTIVITY PATTERN ANALYSIS

Science.gov (United States)

The incorporation of reductive transformations into environmental fate models requires the characterization of natural reductants in well-characterized sediments and aquifer materials. For this purpose, reactivity patterns (i.e., the range and relative order of reactivity) for a...

Low Temperature Solid-State Synthesis and Characterization of LaBO3

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Azmi Seyhun KIPÇAK

2016-11-01

Full Text Available Rare earth (lanthanide series borates, possess high vacuum ultraviolet (VUV transparency, large electronic band gaps, chemical and environmental stability and exceptionally large optical damage thresholds and used in the development of plasma display panels (PDPs. In this study the synthesis of lanthanum borates via solid-state method is studied. For this purpose, lanthanum oxide (La2O3 and boric acid (H3BO3 are used for as lanthanum and boron sources, respectively. Different elemental molar ratios of La to B (between 3:1 to 1:6 as La2O3:H3BO3 were reacted by solid-state method at the reaction temperatures between 500°C - 700°C with the constant reaction time of 4 h. Following the synthesis, characterizations of the synthesized products are conducted by X-ray diffraction (XRD, Fourier transform infrared spectroscopy (FT-IR, Raman spectroscopy and scanning electron microscope (SEM. From the results of the experiments, three types of lanthanum borates of; La3BO6, LaBO3 and La(BO23 were observed at different reaction parameters. Among these three types of lanthanum borates LaBO3 phase were obtained as a major phase.

Synthesis, characterization and antibacterial study on the chitosan-functionalized Ag nanoparticles.

Science.gov (United States)

Biao, Linhai; Tan, Shengnan; Wang, Yuanlin; Guo, Ximin; Fu, Yujie; Xu, Fengjie; Zu, Yuangang; Liu, Zhiguo

2017-07-01

This study provided a facile, one-step hydrothermal method to synthesize stable Ag colloid in aqueous solution by utilizing chitosan as both reductant and stabilizer. The formation of chitosan-functionalized Ag nanoparticles was verified by UV-Vis, FTIR, TEM, AFM and XRD measurements. FTIR results revealed that the primary amine groups and amide groups of chitosan have specific interactions with the surface of Ag nanoparticles. The average diameter of the Ag nanoparticles is 10.0±5.4nm as determined by TEM. Ag nanoparticles are highly crystalline as revealed by HR-TEM and XRD measurements. The size and shape of Ag nanoparticles are also found to depend on the pH condition in the synthesis. Ag nanoparticles were the main products at pH5.0 whereas large Ag nanotriangle and truncated triangular nanoplate were dominant at pH4.0 in the synthesis. Due to its monodispersity and good stability, the chitosan-functionalized Ag colloid synthesized at pH5.0 was further tested for its antibacterial activities against gram-positive bacteria, gram-negative bacteria and fungus. The results of zone of inhibition, inhibition ratio and SEM characterization revealed that chitosan-functionalized Ag nanoparticles have great bactericidal efficiency against both bacteria and fungus. Copyright © 2017 Elsevier B.V. All rights reserved.

W-reactivation of phage lambda in X-irradiated mutants of Escherichia coli K-12

Energy Technology Data Exchange (ETDEWEB)

Martignoni, K D; Haselbacher, I [Muenchen Univ. (Germany, F.R.). Strahlenbiologisches Inst.

1980-07-01

The survival of UV irradiated phage lambda was increased on X-irradiated E.coli K-12 host cells over that on unirradiated cells. The frequency of c mutants among the surviving phages was increased to a similar extent by the X-ray exposure of the host cells as by UV light. This W-reactivation of phage lambda occurred in uvrA, polA, and recB mutants besides the wild type at about equal X-ray doses, but at a reduced reactivation efficiency compared with the wild type. W-reactivation was undetectable in recA mutants. While maximal UV induced W-reactivation occured 30 min after irradiation, the maximal X-ray induced reactivation was found immediately after irradiation. Chloramphenicol (100 ..mu..g/ml) and nitrofurantoin (50 ..mu..g/ml) inhibited W-reactivation of phage lambda if added before irradiation of the host cells, indicating the necessity of protein synthesis for W-reactivation.

Synthesis and characterization of zirconium molybdates of 99 Mo/99m Tc generators

International Nuclear Information System (INIS)

Contreras R, A.; Monroy G, F.; Diaz A, L.V.

2002-01-01

The zirconium molybdates are gels which are used as cation exchangers in the production of 99 Mo/ 99m Tc generators. The synthesis method and the characterization of these gels by thermogravimetry, infrared spectroscopy and X-ray diffraction is presented with the purpose of finding which the factors are that influence in the efficiency of the 99m Tc production. The results show that the quantity of molecular water contained in gel, is possibly the cause of variations of the efficiencies of the 99 Mo/ 99m Tc generator. (Author)

Measurements of total OH reactivity during PROPHET-AMOS 2016

Science.gov (United States)

Rickly, P.; Sakowski, J.; Bottorff, B.; Lew, M.; Stevens, P. S.; Sklaveniti, S.; Locoge, N.; Dusanter, S.

2017-12-01

As one of the main oxidant in the atmosphere, the hydroxyl radical (OH) initiates the oxidation of volatile organic compounds that can lead to the formation of ozone and secondary organic aerosols. Understanding both the sources and sinks of OH is therefore important to address issues related to air quality and climate change. Measurements of total OH reactivity can provide an important test of our understanding of the OH radical budget. Recent measurements of total reactivity in many environments have been greater than calculated based on the measured concentration of VOCs, suggesting that important OH sinks in these environments are not well characterized. Measurements of total OH reactivity were performed in a forested environment during the PROPHET - AMOS field campaign (Program for Research on Oxidants: PHotochemisty, Emissions, and Transport - Atmospheric Measurements of Oxidants in Summer) using the Comparative Reactivity Method (CRM) and the Total OH Loss Rate Method (TOHLM). The site is characterized by large emissions of isoprene and monoterpenes and low anthropogenic influence. Measurements of total OH reactivity using these two techniques agree to within their respective uncertainties, giving confidence in the measured OH reactivity. In addition, measurements of trace gases (VOCs, NOx, O3) were used to perform a comprehensive apportionment of OH sinks. These measurements are used in a chemical model using the Master Chemical Mechanism to calculate the expected OH reactivity. The results will be compared to previous measurements of total OH reactivity at this site.

Synthesis of Cyclic Polymers and Characterization of Their Diffusive Motion in the Melt State at the Single Molecule Level

KAUST Repository

Habuchi, Satoshi; Yamamoto, Takuya; Tezuka, Yasuyuki

2016-01-01

We demonstrate a method for the synthesis of cyclic polymers and a protocol for characterizing their diffusive motion in a melt state at the single molecule level. An electrostatic self-assembly and covalent fixation (ESA-CF) process is used

Fully automated synthesis of (phosphopeptide arrays in microtiter plate wells provides efficient access to protein tyrosine kinase characterization

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Goldstein David J

2005-01-01

Full Text Available Abstract Background Synthetic peptides have played a useful role in studies of protein kinase substrates and interaction domains. Synthetic peptide arrays and libraries, in particular, have accelerated the process. Several factors have hindered or limited the applicability of various techniques, such as the need for deconvolution of combinatorial libraries, the inability or impracticality of achieving full automation using two-dimensional or pin solid phases, the lack of convenient interfacing with standard analytical platforms, or the difficulty of compartmentalization of a planar surface when contact between assay components needs to be avoided. This paper describes a process for synthesis of peptides and phosphopeptides on microtiter plate wells that overcomes previous limitations and demonstrates utility in determination of the epitope of an autophosphorylation site phospho-motif antibody and utility in substrate utilization assays of the protein tyrosine kinase, p60c-src. Results The overall reproducibility of phospho-peptide synthesis and multiplexed EGF receptor (EGFR autophosphorylation site (pY1173 antibody ELISA (9H2 was within 5.5 to 8.0%. Mass spectrometric analyses of the released (phosphopeptides showed homogeneous peaks of the expected molecular weights. An overlapping peptide array of the complete EGFR cytoplasmic sequence revealed a high redundancy of 9H2 reactive sites. The eight reactive phospopeptides were structurally related and interestingly, the most conserved antibody reactive peptide motif coincided with a subset of other known EGFR autophosphorylation and SH2 binding motifs and an EGFR optimal substrate motif. Finally, peptides based on known substrate specificities of c-src and related enzymes were synthesized in microtiter plate array format and were phosphorylated by c-Src with the predicted specificities. The level of phosphorylation was proportional to c-Src concentration with sensitivities below 0.1 Units of

Synthesis and characterization of cathode, anode and electrolyte materials for rechargeable lithium batteries

Science.gov (United States)

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

Synthesis and characterization of a binary oxide ZrO2–TiO2 and its ...

Indian Academy of Sciences (India)

Administrator

Synthesis and characterization of a binary oxide ZrO2–TiO2 and its application in ... Solar cells based on dye-sensitized TiO2 nanoparticles were first developed by Grätzel ... cells, resulting in high Jsc (short-circuit current density),. *Author for .... simple method to study dye sensitization of semiconduc- tors. It is found that the ...

Synthesis and characterization of optical and electrical composite hybrid PVAl/CdS

International Nuclear Information System (INIS)

Oliveira, M.S.; Aquino, H.A.

2010-01-01

Aiming to develop new hybrid nanocomposite materials that present the physical properties of both components which allows to be applied in a variety of areas of nanotechnology among them in photonics, optoelectronics and sensor. The hybrid organic / inorganic PVAl / CdS is compound of a polymer matrix the polyvinyl alcohol (PVAl) and phase second cadmium sulfide (CdS), the synthesis was to did using the 'hydrothermal method' with five different concentrations of CdS between 0.05 and 0.7% (w/w). The hybrid solution obtained is to put sth down on glass substrate by the method 'Casting' so we get films with thicknesses ranging from 20 and 150 μm. The morphology of the films was characterized by X ray diffraction (DRX) and ultraviolet-visible spectroscopy (UV-vis). And the influence of CdS on the dielectric behavior in the films of PVAl / CdS, as dielectric relaxation (relaxation frequencies) were characterized by impedance spectroscopy. (author)

Synthesis and characterization of cationic lipid coated magnetic nanoparticles using multiple emulsions as microreactors

Energy Technology Data Exchange (ETDEWEB)

Akbaba, Hasan; Karagöz, Uğur [Ege University, Faculty of Pharmacy, Department of Pharmaceutical Biotechnology, 35100 Izmir (Turkey); Selamet, Yusuf [Izmir Institute of Technology, Faculty of Science, Department of Physics, 35433 Izmir (Turkey); Kantarcı, A. Gülten, E-mail: gulten.kantarci@ege.edu.tr [Ege University, Faculty of Pharmacy, Department of Pharmaceutical Biotechnology, 35100 Izmir (Turkey)

2017-03-15

The aim of this study was to develop a novel iron oxide nanoparticle synthesis method with in-situ surface coating. For this purpose multiple emulsions were used as microreactors for the first time and magnetic iron oxide particles synthesized in the core of cationic solid lipid nanoparticles. DLS, SEM, TEM, VSM, Raman Spectrometer, XRD, and XPS techniques were performed for characterization of the magnetic nanoparticles. Obtained magnetic nanoparticles are superparamagnetic and no additional process was needed for surface adjustments. They are positively charged as a result of cationic lipid coating and has appropriate particle size (<30 nm) for drug or nucleic acid delivery. Structure analysis showed that magnetic core material is in the form of magnetite. Saturation magnetization value was measured as 15–17 emu g{sup −1} for lipid coated magnetic nanoparticles obtained by multiple emulsion method which is reasonably sufficient for magnetic targeting. - Highlights: • A novel iron oxide nanoparticle synthesis method with in-situ surface coating. • Combining advantages of microemulsions and multiple emulsion methods. • Multiple emulsions were used as microreactors for magnetic nanoparticle synthesis. • Superparamagnetic iron oxide particles synthesized in the core of cationic lipids. • Possible delivery systems for nucleic acids, oil soluble compounds or drugs.

Synthesis and reactivity of uranium (III) cyclopentadienyl complexes

International Nuclear Information System (INIS)

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

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

International Nuclear Information System (INIS)

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.)

Synthesis and Characterization of Processable Polyaniline Salts

International Nuclear Information System (INIS)

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.

Synthesis and characterization of magnetite nanoparticles encapsulated in a bovine hemoglobin microgel

Science.gov (United States)

Mody, Puja J.

This study shows the successful synthesis and characterization of a novel material that is composed of iron oxide particles within a protein gel. During the synthesis, bovine hemoglobin surrounds the forming Fe 3O4 nanoparticles, resulting in a biocompatible hydrogel, which has the potential to be used as a targeted drug delivery vehicle and as an MRI contrast agent. The structure, size, and thermal stability of these hydrogel complexes were analyzed using a range of techniques. Powder x-ray diffraction and infrared spectroscopy indicated the presence of Fe3O 4 and hemoglobin without significant interactions between particles in the solid state. Microscopy analysis determined the average size of these microgel complexes to be 4-9 mum2 in area (˜2-3 mum in diameter), and DSC analysis indicated that none of the microgels exhibited a denaturing or unfolding transition below 54°C regardless of the iron: hemoglobin ratio. Initial testing has been performed on the ability of these materials to act as magnetically activated drug delivery vehicles. Other pertinent tests (for magnetic properties and MRI applicability) are currently proceeding at external labs.

A comparison of serum amyloid A (SAA) synthesis with that of the pentraxins: Serum amyloid P (SAP) and C-reactive protein (CRP)

International Nuclear Information System (INIS)

Tatsuta, E.; Shirahama, T.; Sipe, J.D.; Skinner, M.

1986-01-01

Serum amyloid A (SAA) and serum amyloid P (SAP) were detected in cultures of hepatocytes which had been isolated from normal CBA/J mice by the collagenase perfusion technique. SAP production in 24 h cultures was more resistant than SAA and total protein synthesis to inhibition by actinomycin D, but was more sensitive to inhibition by 48 h. However, the production of SAP was more sensitive to cycloheximide than SAA and total protein throughout the 48 hr incubation period. SAP and SAA levels in the culture media were suppressed by treatment of liver cells with 10 -6 M of colchicine for 48 h. Inhibition of SAP production by colchicine was the same regardless of culture condition, but the effect of colchicine on SAA synthesis varied according to the presence of serum of monokine. These observations also support the concept that the two amyloid proteins are produced under different regulatory mechanisms. When C-reactive protein (CRP) was not detected in the sera of patients with severe chronic liver diseases, the SAA levels were very low. When CRP was detected, SAA values were within the normal range. Thus, in order to produce SAA, liver cells in these patients not only were viable but also maintained their specialized function

Synthesis and characterization ligand tris-(2-thiosalicylamidoethyl)amine and its iron complexes and indium

International Nuclear Information System (INIS)

Guerra-Garcia, Pedro Pablo; Valle Bourrouet, Grettel

2006-01-01

The synthesis of coordination chemistry ligand tris-(2-tiosalicilamidoetil)amine is presented within the framework of study of tripod ligands, the corresponding complexes of iron and indium. Also, its spectroscopic characterization by proton magnetic resonance is showed; so the influence of ligand on a redox active metal and an inactive is compared. Electrochemical methods have been used. The presence of sulfur atoms modifies the redox and magnetic behavior of iron ion (III), as has been found in other similar ligands [es

Synthesis and characterization of CdS/PVA nanocomposite films

Science.gov (United States)

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.

Synthesis and characterization of CdS/PVA nanocomposite films

International Nuclear Information System (INIS)

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

Synthesis and characterization of palm oil fuel ash (POFA) and metakaolin based geopolymer for possible application in nanocoating

Science.gov (United States)

Khan, Ihsan Ullah; Bhat, A. H.; Masset, Patrick J.; Khan, Farman Ullah; Rehman, Wajid Ur

2016-11-01

The main aim of this study was to synthesize and characterize highly amorphous geopolymer from palm oil fuel ash (POFA) and metakaolin, to be used as nanocoating. Geopolymers are man-made aluminosilicate materials that are amorphous analogues of zeolites. The geopolymers were made by condensing a mixture of raw materials metakaolin and palm oil fuel ash (POFA) with alkaline activator at a fixed ratio at room temperature. The kaolin type clay was calcined at 700 °C for 4hrs to transform it into amorphous metakaolin which is more reactive precursor for geopolymer formation. The characteristics of metakaolin and geopolymers (metakaolin and palm oil fuel ash based geopolymers) were analyzed by using x-ray fluorescence (XRF), Fourier transform infra-red spectrometry (FTIR), Thermogravimetric analysis (TG/DTA) and scanning electron microscopy with energy dispersive x-ray analysis (SEM-EDX). FTIR revealed the presence of Al-O and Si-O stretching vibrations of amorphous alumino-silicate structure for metakaolin, palm oil fuel ash and geopolymers. SEM-EDX images showed the presence of reaction product complementary to NASH (N = Na2O, A = Al2O3, S = SiO2, H = H2O) solid. The resulting geopolymers that were synthesized with NaOH/Na2SiO3 solution cured at 60 °C for 3 days. The results demonstrated the suitability of metakaolin and palm oil fuel ash (POFA) for synthesis of geopolymer at room temperatures.

Nanoparticle synthesis of zinc peroxide: structural and morphological characterization for bactericidal applications

International Nuclear Information System (INIS)

Colonia, Roberto; Martinez, Vanessa C.; Solis, Jose L.; Gomez, Monica M.

2013-01-01

Zinc peroxide (ZnO 2 ) nanoparticles were synthesized by sol-gel technique. The chemicals used for the synthesis were zinc acetate di-hydrate (Zn(CH 3 COO) 2. 2H 2 O) and hydrogen peroxide (H 2 O 2 ) at 30 % in an aqueous solution with sonication. The structure of the ZnO 2 nanoparticles was characterized by X-ray diffraction. While the morphology and the cluster size were determined using scanning and transmission electron microscopy. For a preliminary evaluation of the bactericidal properties of the ZnO 2 , the material was exposed to Staphylococcus aureus, Escherichia coli y Bacillus subtili, and the nanoparticles presented good bactericidal properties. (author)

Design, synthesis, and characterization of fluorine-free PAGs for 193-nm lithography

Science.gov (United States)

Liu, Sen; Glodde, Martin; Varanasi, Pushkara R.

2010-04-01

Photoacid generators (PAGs) are a key component in chemically amplified resists used in photolithography. Perfluorooctanesulfonates (PFOS) and other perfluoroalkylsulfonates (PFAS) have been well adopted as PAGs in 193 nm photoresist. Recently, concerns have been raised about their environmental impact due to their chemical persistency, bioaccumulation and toxicity. It is a general interest to find environmentally benign PAGs that are free of fluorine atoms. Here we describe the design, synthesis and characterization of a series of novel fluorine-free onium salts as PAGs for 193 nm photoresists. These PAGs demonstrated desirable physical and lithography properties when compared with PFAS-based PAGs for both dry and immersion exposures.

Synthesis, Characterization, and Computational Modeling of N-(1-Ethoxyvinylpyridinium Triflates, an Unusual Class of Pyridinium Salts

Directory of Open Access Journals (Sweden)

Jonathan D. Shapiro

2018-02-01

Full Text Available N-Substituted pyridinium salts constitute one of the most valuable reagent classes in organic synthesis, due to their versatility and ease of use. Herein we report a preliminary synthesis and detailed structural analysis of several N-(1-ethoxyvinylpyridinium triflates, an unusual class of pyridinium salts with potentially broad use as a reagent in organic synthesis. Treatment of pyridines with trifluoromethane sulfonic acid and ethoxyacetylene generates stable, isolable adducts which have been extensively characterized, due to their novelty. Three-dimensional structural stability is perpetuated by an array of C–H•••O hydrogen bonds involving oxygen atoms from the –SO3 groups of the triflate anion, and hydrogen atoms from the aromatic ring and vinyl group of the pyridinium cation. Predictions from density functional theory calculations of the energy landscape for rotation about the exocyclic C–N bond of 2-chloro-1-(1-ethoxyvinylpyridine-1-ium trifluoromethanesulfonate (7 and 1-(1-ethoxyvinylpyridine-1-ium trifluoromethanesulfonate (16 are also reported. Notably, the predicted global energy minimum of 7 was nearly identical to that found within the crystal structure.

Combinatorial Strategies for Synthesis and Characterization of Alloy Microstructures over Large Compositional Ranges.

Science.gov (United States)

Li, Yanglin; Jensen, Katharine E; Liu, Yanhui; Liu, Jingbei; Gong, Pan; Scanley, B Ellen; Broadbridge, Christine C; Schroers, Jan

2016-10-10

The exploration of new alloys with desirable properties has been a long-standing challenge in materials science because of the complex relationship between composition and microstructure. In this Research Article, we demonstrate a combinatorial strategy for the exploration of composition dependence of microstructure. This strategy is comprised of alloy library synthesis followed by high-throughput microstructure characterization. As an example, we synthesized a ternary Au-Cu-Si composition library containing over 1000 individual alloys using combinatorial sputtering. We subsequently melted and resolidified the entire library at controlled cooling rates. We used scanning optical microscopy and X-ray diffraction mapping to explore trends in phase formation and microstructural length scale with composition across the library. The integration of combinatorial synthesis with parallelizable analysis methods provides a efficient method for examining vast compositional ranges. The availability of microstructures from this vast composition space not only facilitates design of new alloys by controlling effects of composition on phase selection, phase sequence, length scale, and overall morphology, but also will be instrumental in understanding the complex process of microstructure formation in alloys.

Synthesis and characterization of carbon cryogel microspheres from lignin-furfural mixtures for biodiesel production.

Science.gov (United States)

Zainol, Muzakkir Mohammad; Amin, Nor Aishah Saidina; Asmadi, Mohd

2015-08-01

The aim of this work was to study the potential of biofuel and biomass processing industry side-products as acid catalyst. The synthesis of carbon cryogel from lignin-furfural mixture, prepared via sol-gel polycondensation at 90°C for 0.5h, has been investigated for biodiesel production. The effect of lignin to furfural (L/F) ratios, lignin to water (L/W) ratios and acid concentration on carbon cryogel synthesis was studied. The carbon cryogels were characterized and tested for oleic acid conversion. The thermally stable amorphous spherical carbon cryogel has a large total surface area with high acidity. Experimental results revealed the optimum FAME yield and oleic acid conversion of 91.3wt.% and 98.1wt.%, respectively were attained at 65°C for 5h with 5wt.% catalyst loading and 20:1 methanol to oleic acid molar ratio. Therefore, carbon cryogel is highly potential for heterogeneous esterification of free fatty acid to biodiesel. Copyright © 2015 Elsevier Ltd. All rights reserved.

Synthesis and characterization of novel silver nanoparticles using Chamaemelum nobile extract for antibacterial application

Science.gov (United States)

Erjaee, Hoda; Rajaian, Hamid; Nazifi, Saeed

2017-06-01

The present study reports green synthesis of silver nanoparticles (AgNPs) at room temperature using aqueous Chamaemelum nobile extract for the first time. The effect of silver nitrate concentration, quantity of the plant extract and the reaction time on particle size was optimized and studied by UV-Vis spectroscopy and dynamic light scattering. The appearance of brownish color with λ max of 422 nm confirmed the formation of AgNPs. Synthesized nanoparticles were further characterized by Fourier transform infrared spectroscopy, x-ray diffraction and transmission electron microscopy. In addition, antimicrobial activity of the AgNPs against Escherichia coli, Salmonella typhimurium, Staphylococcus aureus and Bacillus subtilis was evaluated based on the inhibition zone using the disc-diffusion assay and measurement of minimal inhibition concentration and minimal bactericidal concentration by standard microdilution method. In conclusion, synthesis of nanoparticle with aqueous Chamaemelum nobile extract is simple, rapid, environmentally benign and inexpensive. Moreover, these synthesized nanoparticles exhibit significant antibacterial activity.

Zinc acetylacetonate hydrate adducted with nitrogen donor ligands: Synthesis, spectroscopic characterization, and thermal analysis

Science.gov (United States)

Brahma, Sanjaya; Shivashankar, S. A.

2015-12-01

We report synthesis, spectroscopic characterization, and thermal analysis of zinc acetylacetonate complex adducted by nitrogen donor ligands, such as pyridine, bipyridine, and phenanthroline. The pyridine adducted complex crystallizes to monoclinic crystal structure, whereas other two adducted complexes have orthorhombic structure. Addition of nitrogen donor ligands enhances the thermal property of these complexes as that with parent metal-organic complex. Zinc acetylacetonate adducted with pyridine shows much higher volatility (106 °C), decomposition temperature (202 °C) as that with zinc acetylacetonate (136 °C, 220 °C), and other adducted complexes. All the adducted complexes are thermally stable, highly volatile and are considered to be suitable precursors for metal organic chemical vapor deposition. The formation of these complexes is confirmed by powder X-ray diffraction, Fourier transform infrared spectroscopy, mass spectroscopy, and elemental analysis. The complexes are widely used as starting precursor materials for the synthesis of ZnO nanostructures by microwave irradiation assisted coating process.

Synthesis and Characterization of Monometallic (Ag, Cu and Bimetallic Ag-Cu Particles for Antibacterial and Antifungal Applications

Directory of Open Access Journals (Sweden)

Marta Paszkiewicz

2016-01-01

Full Text Available In this paper, the experimental studies are concerned with the effect of the synthesis parameters on the formation of monometallic Ag and Cu nanoparticles (NPs. We consider the synthesis strategies verification for the bimetallic core-shell and alloy particles preparation. It was successfully obtained by chemical reduction method. The obtained colloidal solution is characterized by the transmission electron microscopy (TEM with energy-dispersive X-ray spectroscopy (EDX data, UV-Vis spectra, particle size distribution, and zeta potential. This work presents a comprehensive overview of experimental studies of the most stable colloidal solutions to impregnate fabrics that will exhibit a bactericidal and fungicidal activity against Candida albicans, Escherichia coli, and Staphylococcus aureus.

Hydrothermal Synthesis and Characterization of a Metal-Organic Framework by Thermogravimetric Analysis, Powder X-Ray Diffraction, and Infrared Spectroscopy: An Integrative Inorganic Chemistry Experiment

Science.gov (United States)

Crane, Johanna L.; Anderson, Kelly E.; Conway, Samantha G.

2015-01-01

This advanced undergraduate laboratory experiment involves the synthesis and characterization of a metal-organic framework with microporous channels that are held intact via hydrogen bonding of the coordinated water molecules. The hydrothermal synthesis of Co[subscript 3](BTC)[subscript 2]·12H[subscript 2]O (BTC = 1,3,5-benzene tricarboxylic acid)…

Synthesis and characterization of zeolite P using technical-grade materials

CERN Document Server

Aghabozorg, H R; Aghabozorg, H R; Sharif, M

2001-01-01

Research attempts on zeolites show structural and industrial importance of these inorganic compounds. In this regard, the synthesis of zeolites is of great importance, because their natural occurring counterparts are often impure. Zeolite Na-P with a silicon to aluminium ratio of one has a better ion exchange capacity than Na-A and can be used as a detergent builder. In this work, zeolite Na-P of high purity was successfully synthesized using commercial silica and alumina sources. parameters such as H sub 2 O:A1 sub 2 O sub 3 and SiO sub 2 :A1 sub 2 O sub 3 molar ratios and crystallization temperature and time were investigated. So that the optimum condition was obtained. X-ray powder diffraction, infrared, scanning electron microscopy and elemental analysis were utilized for the characterization of the product.

Metal-organic frameworks: structure, properties, methods of synthesis and characterization

International Nuclear Information System (INIS)

Butova, V V; Soldatov, M A; Guda, A A; Lomachenko, K A; Lamberti, C

2016-01-01

This review deals with key methods of synthesis and characterization of metal-organic frameworks (MOFs). The modular structure affords a wide variety of MOFs with different active metal sites and organic linkers. These compounds represent a new stage of development of porous materials in which the pore size and the active site structure can be modified within wide limits. The set of experimental methods considered in this review is sufficient for studying the short-range and long-range order of the MOF crystal structure, determining the morphology of samples and elucidating the processes that occur at the active metal site in the course of chemical reactions. The interest in metal-organic frameworks results, first of all, from their numerous possible applications, ranging from gas separation and storage to chemical reactions within the pores. The bibliography includes 362 references

Synthesis and characterization of acrylate copolymer containing fluorescein functional group

Energy Technology Data Exchange (ETDEWEB)

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.

Synthesis and characterization of NiO nanoparticles by Pechini method

International Nuclear Information System (INIS)

Nascimento, A.; Ribeiro, M.A.; Costa, A.C.F.M.; Gama, L.; Bernardi, M.I.B.

2009-01-01

In recent years, ultrafine magnetic particles of NiO have attracting the attention because of its unknown behavior, enormous scientific potential and technological application. Some of its more important properties are accented magnetic moments, double dynamic exchange, quantization of wave of spin and etc. In this context, this work has for objective to synthesize and to characterize nanoparticles of NiO for the Pechini method. The powder was analyzed by X-rays diffraction. The results of scanning electron microscopy, adsorption of nitrogen. The analysis of X-rays diffraction of the sample showed single-phase peaks of NiO, with crystallite size close to 38 nm. The surface area was 6.44 m 2 /g. The image from scanning electron microscopy shows soft homogeneous agglomerates. The Pechini synthesis was efficient in the production of powders of NiO nano metrics and single-phase. (author)

Ionic Liquids: Radiation Chemistry, Solvation Dynamics and Reactivity Patterns

International Nuclear Information System (INIS)

Wishart, J.F.

2008-01-01

Ionic liquids (ILs) are a rapidly expanding family of condensed-phase media with important applications in energy production, nuclear fuel and waste processing, improving the efficiency and safety of industrial chemical processes, and pollution prevention. ILs are generally nonvolatile, noncombustible, highly conductive, recyclable and capable of dissolving a wide variety of materials. They are finding new uses in chemical synthesis, catalysis, separations chemistry, electrochemistry and other areas. Ionic liquids have dramatically different properties compared to conventional molecular solvents, and they provide a new and unusual environment to test our theoretical understanding of charge transfer and other reactions. We are interested in how IL properties influence physical and dynamical processes that determine the stability and lifetimes of reactive intermediates and thereby affect the courses of chemical reactions and product distributions. Successful use of ionic liquids in radiation-filled environments, where their safety advantages could be significant, requires an understanding of ionic liquid radiation chemistry. For example, characterizing the primary steps of IL radiolysis will reveal radiolytic degradation pathways and suggest ways to prevent them or mitigate their effects on the properties of the material. An understanding of ionic liquid radiation chemistry will also facilitate pulse radiolysis studies of general chemical reactivity in ILs, which will aid in the development of applications listed above. Very early in our radiolysis studies it became evident that slow solvation dynamics of the excess electron in ILs (which vary over a wide viscosity range) increases the importance of pre-solvated electron reactivity and consequently alters product distributions. Parallel studies of IL solvation phenomena using coumarin-153 dynamic Stokes shifts and polarization anisotropy decay rates are done to compare with electron solvation studies and to evaluate

IONIC LIQUIDS: RADIATION CHEMISTRY, SOLVATION DYNAMICS AND REACTIVITY PATTERNS

International Nuclear Information System (INIS)

WISHART, J.F.

2007-01-01

energy production, nuclear fuel and waste processing, improving the efficiency and safety of industrial chemical processes, and pollution prevention. ILs are generally nonvolatile, noncombustible, highly conductive, recyclable and capable of dissolving a wide variety of materials. They are finding new uses in chemical synthesis, catalysis, separations chemistry, electrochemistry and other areas. Ionic liquids have dramatically different properties compared to conventional molecular solvents, and they provide a new and unusual environment to test our theoretical understanding of charge transfer and other reactions. We are interested in how IL properties influence physical and dynamical processes that determine the stability and lifetimes of reactive intermediates and thereby affect the courses of chemical reactions and product distributions. Successful use of ionic liquids in radiation-filled environments, where their safety advantages could be significant, requires an understanding of ionic liquid radiation chemistry. For example, characterizing the primary steps of IL radiolysis will reveal radiolytic degradation pathways and suggest ways to prevent them or mitigate their effects on the properties of the material. An understanding of ionic liquid radiation chemistry will also facilitate pulse radiolysis studies of general chemical reactivity in ILs, which will aid in the development of applications listed above. Very early in our radiolysis studies it became evident that slow solvation dynamics of the excess electron in ILs (which vary over a wide viscosity range) increases the importance of pre-solvated electron reactivity and consequently alters product distributions. Parallel studies of IL solvation phenomena using coumarin-153 dynamic Stokes shifts and polarization anisotropy decay rates are done to compare with electron solvation studies and to evaluate the influence of ILs on charge transport processes. Methods. Picosecond pulse radiolysis studies at BNL

Synthesis, Characterization and Optical Constants of Silicon Oxycarbide

Directory of Open Access Journals (Sweden)

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.

Synthesis, characterization and a.c. magnetic analysis of magnetite nanoparticles

International Nuclear Information System (INIS)

Riani, P.; Napoletano, M.; Canepa, F.

2011-01-01

In the last years, the study of Fe-based magnetic nanoparticles (MNP) has attracted increasing interest either for the physical properties shown by nanosized materials (electric and magnetic properties are strongly affected by dimension and surface effects) either for the different technological applications of these materials (catalysis, drug delivery, magnetic resonance imaging, contaminants removal from groundwater, new exchange coupled magnets, soft nanomagnets for high frequency applications, etc.). In this article, the results obtained in the synthesis and characterization of the Fe 3 O 4 MNP is reported. The magnetite nanoparticles were synthesized by a modified Massart method. Structural characterization was performed using X-ray diffraction analysis and a complete morphological and dimensional study was carried out by means of Transmission Electron Microscopy, and a.c. magnetic susceptibility measured as a function of the frequency of the applied magnetic field. Diameters of the superparamagnetic Fe 3 O 4 nanoparticles are ranging from 2 to 10 nm, as evidenced by all the techniques employed. The size distribution of the hydrated aggregates in solution has been obtained by quantitative analysis of the frequency dependence of the a.c. susceptibility. The mathematical approach adopted will be described and all the obtained results will be compared and discussed.

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

Science.gov (United States)

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

Radiation synthesis and characterization of zinc phthalocyanine composite based on 2-hydroxyethyl methacrylate/methyl methacrylate copolymer

International Nuclear Information System (INIS)

Abdel Ghaffar, A.M.; Youssef, Tamer E.; Mohamed, Hanan H.

2016-01-01

The synthesis and characterization of new 2-hydroxyethyl methacrylate-co-methyl methacrylate/zinc phthalocyanine composite Poly(HEMA/MMA/ZnPc) is described for the first time in this study. The aim of this research is to present possibility of radiation synthesis of the newly zinc phthalocyanine composites as potential candidates for wide range of applications. Gel (%) and swelling for Poly(hydroxyethyl methacrylate) Poly(HEMA) and the based Poly(hydroxyethyl methacrylate/methyl methacrylate) copolymer Poly(HEMA/MMA) with different composition 100/0, 95/5, 90/10 and 80/20 wt % were evaluated. It was found that Poly(HEMA/MMA) copolymer with composition 95/5 wt % characterized by its high swelling property at pH 7.4. The prepared composites I and II Poly(HEMA/MMA/ZnPc) with composition (95/5/1 wt%) and (95/5/1.5 wt%) respectively have been characterized by FTIR and TGA. The effect of gamma irradiation on the chemical properties of composite I was described. It is observed that the Zinc phthalocyanine with low concentration 1 wt % enhance chemical, thermal properties and stabilization against gamma radiation of the prepared composite I. - Highlights: • The preparation of Poly(HEMA/MMA/ZnPc) by radiation forming modified composites. • The low concentration of ZcPc (1 or 1.5 wt %) lead to form outstanding properties. • These composites are a potential candidate for wide range of applications.

Radiation synthesis and characterization of zinc phthalocyanine composite based on 2-hydroxyethyl methacrylate/methyl methacrylate copolymer

Energy Technology Data Exchange (ETDEWEB)

Abdel Ghaffar, A.M., E-mail: am_abdelghaffar@yahoo.com [Radiation Research of Polymer Chemistry Department, Industrial Irradiation Division, National Center for Radiation Research and Technology, Atomic Energy Authority P.O. Box 29, Nasr City, Cairo (Egypt); Youssef, Tamer E. [Applied Organic Chemistry Department, Chemical Industries Research Division, National Research Center, Dokki, Cairo, 12622 (Egypt); Chemical and Materials Engineering Department, Faculty of Engineering, King Abdulaziz University, P.O. Box 80204, Jeddah, 21589 (Saudi Arabia); Mohamed, Hanan H. [Chemistry Department, Faculty of Science, Helwan University, Ain Helwan, Cairo (Egypt)

2016-08-01

The synthesis and characterization of new 2-hydroxyethyl methacrylate-co-methyl methacrylate/zinc phthalocyanine composite Poly(HEMA/MMA/ZnPc) is described for the first time in this study. The aim of this research is to present possibility of radiation synthesis of the newly zinc phthalocyanine composites as potential candidates for wide range of applications. Gel (%) and swelling for Poly(hydroxyethyl methacrylate) Poly(HEMA) and the based Poly(hydroxyethyl methacrylate/methyl methacrylate) copolymer Poly(HEMA/MMA) with different composition 100/0, 95/5, 90/10 and 80/20 wt % were evaluated. It was found that Poly(HEMA/MMA) copolymer with composition 95/5 wt % characterized by its high swelling property at pH 7.4. The prepared composites I and II Poly(HEMA/MMA/ZnPc) with composition (95/5/1 wt%) and (95/5/1.5 wt%) respectively have been characterized by FTIR and TGA. The effect of gamma irradiation on the chemical properties of composite I was described. It is observed that the Zinc phthalocyanine with low concentration 1 wt % enhance chemical, thermal properties and stabilization against gamma radiation of the prepared composite I. - Highlights: • The preparation of Poly(HEMA/MMA/ZnPc) by radiation forming modified composites. • The low concentration of ZcPc (1 or 1.5 wt %) lead to form outstanding properties. • These composites are a potential candidate for wide range of applications.

Deposition and characterization of NbAIN thin films by reactive magnetron sputtering

International Nuclear Information System (INIS)

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)

Synthesis and Characterization of Highly Intercalated Graphite Bisulfate

OpenAIRE

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...

New functionalized mercaptoundecahydrododecaborate derivatives for potential application in boron neutron capture therapy: synthesis, characterization and dynamic visualization in cells.

Science.gov (United States)

Genady, Afaf R; Ioppolo, Joseph A; Azaam, Mohamed M; El-Zaria, Mohamed E

2015-03-26

A series of mercaptoundecahydrododecaborate (B12H11SH(2-), BSH) bearing mono- and dicarboxyalkyl derivatives was prepared, characterized, and their reactivity towards amidation and esterification in DMF was evaluated. Symmetrical alkylation of BSH was achieved by treatment with primary haloalkyl carboxylic acids in aqueous acetonitrile to produce S,S-bis(carboxyalkyl)sulfonium-undecahydro-closo-dodecaborate tetramethylammonium salts. Unsymmetrically substituted sulfonium salts were obtained through a similar treatment of cyanoethylthioether-undecahydro-closo-dodecaborate tetramethylammonium salt with haloalkyl carboxylic acid. Selective removal of the remaining cyanoethyl group upon treatment with tetramethylammonium hydroxide yielded S-carboxyalkyl-thioether-undecahydro-closo-dodecaborate ditetramethylammonium salts. N,N'-dicyclohexylcarbodiimide (DCC) activated amidation of S,S-bis(carboxyalkyl)sulfonium-undecahydro-closo-dodecaborate or S-carboxyalkyl-thioether-undecahydro-closo-dodecaborate tetramethylammonium salts with propargylamine provided the opportunity to install terminal acetylene groups for further conjugation. These compounds acted as powerful building blocks for the synthesis of a broad range of 1,4-disubstituted 1,2,3-triazole products in high yields, utilizing the Cu(I)-mediated click cycloaddition reaction. The synthesis of BSH-lipid with a two-tailed moiety was also achieved, by esterification of S,S-bis(carboxyethyl)sulfoniumundecahydro-closo-dodecaborate(1-) tetramethylammonium salt with 1,2-O-distearoyl-sn-3-glycerol, which may prove useful in the liposomal boron delivery system. The bio-compatibility of the azide-alkyne click reaction was then utilized by performing this reaction in cell culture. The distribution of BSH in HeLa cells could be visualized by treating the cells first with a BSH-alkyne compound and then with Alexa Fluor 488(®) azide dye. The BSH-dye conjugate, which did not wash out, revealed the distribution of boron in the He

Electrochemically Active Biofilms Assisted Nanomaterial Synthesis for Environmental Applications

KAUST Repository

Ahmed, Elaf

2017-01-01

Nanomaterials have a great potential for environmental applications due to their high surface areas and high reactivity. This dissertation investigated the use of electrochemically active biofilms (EABs) as a synthesis approach for the fabrication

Synthesis and characterization of carbon nano fibers for its application in the adsorption of toxic gases

International Nuclear Information System (INIS)

Juanico L, J.A.

2004-01-01

The production of carbon nano fibers (CNF's) by diverse techniques as the electric arc, laser ablation, or chemical deposition in vapor phase, among other, they have been so far used from final of the 90's. However, the synthesis method by discharge Glow arc of alternating current and high frequency developed by Pacheco and collaborators, is a once alternative for its obtaining. In the plasma Application Laboratory (LAP) of the National Institute of Nuclear Research (INlN) it was designed and manufactured a reactor of alternating current and high frequency that produces a Glow arc able to synthesize carbon nano fibers. Its were carried out nano fibers synthesis with different catalysts to different proportions and with distinct conditions of vacuum pressure and methane flow until obtaining the best nano fibers samples and for it, this nano structures were characterized by Scanning and Transmission Electron Microscopy, X-ray Diffraction, Raman spectrometry and EDS spectrometry. Once found the optimal conditions for the nano fibers production its were contaminated with NO 2 toxic gas and it was determined if they present adsorption, for it was used the thermal gravimetric analysis technique. This work is divided in three parts, in the first one, conformed by the chapters 1, at the 3, they are considered the foundations of the carbon nano fibers, their history, their characteristics, growth mechanisms, synthesis techniques, the thermal gravimetric analysis principles and the adsorption properties of the nano fibers. In the second part, consistent of the chapters 4 and 5, the methodology of synthesis and characterization of the nano fibers is provided. Finally, in third part its were carried out the activation energy calculation, the adsorption of the CNF's is analyzed and the conclusions are carried out. The present study evaluates the adsorption of environmental gas pollutants as the nitrogen oxides on carbon nano fibers at environmental or near conditions. Also

Synthesis and characterization of CuO flower-nanostructure processing by a domestic hydrothermal microwave

International Nuclear Information System (INIS)

Volanti, D.P.; Keyson, D.; Cavalcante, L.S.; Simoes, A.Z.; Joya, M.R.; Longo, E.; Varela, J.A.; Pizani, P.S.; Souza, A.G.

2008-01-01

The synthesis and characterization of CuO flower-nanostructure processed in domestic hydrothermal microwave oven was presented. Phase analysis was carried out using X-ray diffraction (XRD) and micro-Raman scattering (MRS) and the results confirmed the CuO flower-nanostructure as a single-phase. The field-emission scanning electron microscopy (FEG-SEM) was used to estimate the average spheres diameter while transmission electron microscope (TEM) to observe the thorn of the flower-nanostructures. The mechanism of CuO flower-nanostructures formation is proposed and explained

Synthesis and characterization of CuO flower-nanostructure processing by a domestic hydrothermal microwave

Energy Technology Data Exchange (ETDEWEB)

Volanti, D.P. [Laboratorio Interdisciplinar em Ceramica, Departamento de Fisico-Quimica, Instituto de Quimica, Universidade Estadual Paulista, P.O. Box 355, 14801-907 Araraquara, SP (Brazil); Keyson, D. [Laboratorio de Ensino de Ciencias e Laboratorio de Combustiveis e Materiais, Departamento de Quimica, Universidade Federal da Paraiba, 58051-900 Joao Pessoa, PB (Brazil); Cavalcante, L.S. [Laboratorio Interdisciplinar de Eletroquimica e Ceramica, Departamento de Quimica, Universidade Federal de Sao Carlos, P.O. Box 676, 13565-905 Sao Carlos, SP (Brazil)], E-mail: laeciosc@bol.com.br; Simoes, A.Z. [Laboratorio Interdisciplinar em Ceramica, Departamento de Fisico-Quimica, Instituto de Quimica, Universidade Estadual Paulista, P.O. Box 355, 14801-907 Araraquara, SP (Brazil); Joya, M.R. [Departamento de Fisica, Universidade Federal de Sao Carlos, P.O. Box 676, 13565-905 Sao Carlos, SP (Brazil); Longo, E.; Varela, J.A. [Laboratorio Interdisciplinar em Ceramica, Departamento de Fisico-Quimica, Instituto de Quimica, Universidade Estadual Paulista, P.O. Box 355, 14801-907 Araraquara, SP (Brazil); Pizani, P.S. [Departamento de Fisica, Universidade Federal de Sao Carlos, P.O. Box 676, 13565-905 Sao Carlos, SP (Brazil); Souza, A.G. [Laboratorio de Ensino de Ciencias e Laboratorio de Combustiveis e Materiais, Departamento de Quimica, Universidade Federal da Paraiba, 58051-900 Joao Pessoa, PB (Brazil)

2008-07-14

The synthesis and characterization of CuO flower-nanostructure processed in domestic hydrothermal microwave oven was presented. Phase analysis was carried out using X-ray diffraction (XRD) and micro-Raman scattering (MRS) and the results confirmed the CuO flower-nanostructure as a single-phase. The field-emission scanning electron microscopy (FEG-SEM) was used to estimate the average spheres diameter while transmission electron microscope (TEM) to observe the thorn of the flower-nanostructures. The mechanism of CuO flower-nanostructures formation is proposed and explained.

Towards room temperature, direct, solvent free synthesis of tetraborohydrides

International Nuclear Information System (INIS)

Remhof, A; Yan, Y; Friedrichs, O; Kim, J W; Mauron, Ph; Borgschulte, A; Züttel, A; Wallacher, D; Buchsteiner, A; Hoser, A; Oh, K H; Cho, Y W

2012-01-01

Due to their high hydrogen content, tetraborohydrides are discussed as potential synthetic energy carriers. On the example of lithium borohydride LiBH 4 , we discuss current approaches of direct, solvent free synthesis based on gas solid reactions of the elements or binary hydrides and/or borides with gaseous H 2 or B 2 H 6 . The direct synthesis from the elements requires high temperature and high pressure (700°C, 150bar D 2 ). Using LiB or AlB 2 as boron source reduces the required temperature by more than 300 K. Reactive milling of LiD with B 2 H 6 leads to the formation of LiBD 4 already at room temperature. The reactive milling technique can also be applied to synthesize other borohydrides from their respective metal hydrides.

Auto-combustion Synthesis, Characterization and Photovoltaic

African Journals Online (AJOL)

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 ...

Synthesis and characterization of LiFePO{sub 4} cathode preparation by low temperature method

Energy Technology Data Exchange (ETDEWEB)

Rajesh, Desapogu, E-mail: rajesh.desapogu@gmail.com; Srinivas Naik, V.; Sunandana, C.S., E-mail: sunandana@gmail.com

2015-05-01

We review in detail the physics and technology of the novel material LiFePO{sub 4}, a potential cathode material for Li-ion batteries. In the present work, nano crystalline LiFePO{sub 4} film has been synthesized in both powder and thin film forms from a non-aqueous sol–gel synthesis route based on oxalates of Li and Fe (II). Ferrous oxalate has been synthesized indigenously using a ferrous sulphate based chemical reaction and characterized. Nano powders and thin films of LiFePO{sub 4} have been fabricated and coated on stainless steel substrates with the aim of device development in future. The material has been characterized extensively by XRD for crystal structure, FESEM for microstructure, EDS for elemental analysis and FTIR for the internal modes of phosphate ion. Fe{sup 3+} impurity characterization has been done by using ESR.

Preparation and characterization of rare-earth bulks with controllable nanostructures

International Nuclear Information System (INIS)

Song Xiaoyan; Zhang Jiuxing; Li Erdong; Lu Nianduan; Yin Fuxing

2006-01-01

The preparation and characterization of pure rare-earth-metal bulks with controllable nanostructures are reported in this paper. A novel 'oxygen-free' in situ synthesis technique that combines inert-gas condensation with spark plasma sintering (SPS) technology is proposed. Taking into account the special mechanisms of SPS consolidation and the scale effects of nanoparticles, we introduced practical procedures for preparing rare-earth bulks of amorphous, mixed amorphous and nanocrystals, and nanocrystalline microstructures, respectively. Compared with the conventional polycrystalline bulk, these nanostructured bulks exhibit substantially improved physical and mechanical properties. This technique enables comprehensive studies on the microstructures and properties of a large variety of nanostructured metallic materials that are highly reactive in the air

Synthesis of mesoporous silica nanoparticles by sol–gel as nanocontainer for future drug delivery applications

Energy Technology Data Exchange (ETDEWEB)

Vazquez, N.I.; Gonzalez, Z.; Ferrari, B.; Castro, Y.

2017-07-01

Development of mesoporous silica nanoparticles as carriers for drug delivery systems has increased exponentially during the last decade. The present work is focused on the synthesis of silica carriers by sol–gel from tetraethyl orthosilicate (TEOS) as precursor of silica and cetyltrimethylammonium bromide (CTAB) as pore generating agent. The synthesis conditions were modified varying the molar ratio of water/TEOS, NH3/TEOS and amount of CTAB. The silica particles were characterized by scan electron microscopy techniques (FESEM), high resolution transmission electron microscopy (HR-TEM), N2 adsorption–desorption isotherms, Zeta-potential and Dynamic Light Scattering (DLS). The results show that the specific surface area and the porosity of silica particles were strongly affected by the addition of CTAB and the amount of H2O. The dispersion and stability of silica mesoporous particles is achieved in spite of the high surface reactivity. The synthesis formulation affects considerably to the particle morphology, which changes from spheres to rods when the molar ratio of H2O increases. A maximum specific surface area of 1480m2/g was obtained with pore sizes ranging 2.5–2.8nm. (Author)

Synthesis and thermal characterization of xylan-graft-polyacrylonitrile.

Science.gov (United States)

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.

Ultrafast Hydro-Micromechanical Synthesis of Calcium Zincate: Structural and Morphological Characterizations

Directory of Open Access Journals (Sweden)

Vincent Caldeira

2017-01-01

Full Text Available Calcium zincate is a compound with a large panel of application: mainly known as an advantageous replacement of zinc oxide in negative electrodes for air-zinc or nickel-zinc batteries, it is also used as precursor catalyst in biodiesel synthesis and as antifungal compound for the protection of limestone monuments. However, its synthesis is not optimized yet. In this study, it was elaborated using an ultrafast synthesis protocol: Hydro-Micromechanical Synthesis. Two other synthesis methods, Hydrochemical Synthesis and Hydrothermal Synthesis, were used for comparison. In all cases, the as-synthesized samples were analyzed by X-ray diffraction, scanning electron microscopy, and LASER diffraction particle size analysis. Rietveld method was used to refine various structural parameters and obtain an average crystallite size, on a Hydro-Micromechanical submicronic sample. X-ray single crystal structure determination was performed on a crystal obtained by Hydrochemical Synthesis. It has been shown that regardless of the synthesis protocol, the prepared samples always crystallize in the same crystal lattice, with P21/c space group and only differ from their macroscopic textural parameters. Nevertheless, only the Hydro-Micromechanical method is industrially scalable and enables a precise control of the textural parameters of the obtained calcium zincate.

Synthesis and characterization of polyphosphazene electrolytes including cyclic ether side groups

Science.gov (United States)

Fiedler, Carsten; Luerssen, Bjoern; Lucht, Brett; Janek, Juergen

2018-04-01

This paper presents the synthesis and detailed characterization of two polyphosphazene based polymers, including different cyclic ether side groups. The final polymers were obtained by a well-known method employing a living cationic polymerization and subsequent nucleophilic substitution. The synthesized polymers Poly [(1,3-dioxane-5-oxy) (1,3-dioxolane-4-methoxy)phosphazene] (DOPP) and Poly[bis(2-Tetrahydro-3-furanoxy)phosphazene] (THFPP) were mixed with varied amounts of lithium bis(trifluoromethane)sulfonamide (LiTFSI) and the interactions between the salt and the polymer chains were studied by Fourier transform infrared (FT-IR) and differential scanning calorimetry (DSC) measurements. Electrochemical characterization was performed by electrochemical impedance spectroscopy (EIS) and direct current polarization in the temperature range of 20-60 °C. These measurements were utilized to calculate the lithium transference number (t+), the lithium conductivity (σ) and its activation energy in order to elucidate the lithium transport behavior. Relatively high lithium transference numbers of 0.6 (DOPP) and 0.7 (THFPP) at 60 °C are found and reveal maximum lithium conductivities of 2.8·10-6 Sṡcm-1 and 9.0·10-7 Sṡcm-1 for DOPP and THFPP at 60 °C, respectively.

A chemical platform approach on cardanol oil: from the synthesis of building blocks to polymer synthesis

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Jaillet Fanny

2016-09-01

Full Text Available This review proposes a platform approach for the synthesis of various building blocks from cardanol oil in one or two-steps synthesis. Cardanol is a natural phenol issued from Cashew nutshell liquid (CNSL. CNSL is a non-edible renewable resource, co-produced from cashew industry in large commercial volumes. Cardanol is non-toxic and particularly suitable as an aromatic renewable resource for polymers and materials. Various routes were used for the synthesis of di- and poly-functional building blocks used thereafter in polymer syntheses. Phenolation was used to dimerize/oligomerize cardanol to propose increase functionality of cardanol. Thio-ene was used to synthesize new reactive amines. Epoxidation and (methacrylation were also used to insert oxirane or (methacrylate groups in order to synthesize polymers and materials.

Room temperature synthesis of biodiesel using sulfonated ...

Science.gov (United States)

Sulfonation of graphitic carbon nitride (g-CN) affords a polar and strongly acidic catalyst, Sg-CN, which displays unprecedented reactivity and selectivity in biodiesel synthesis and esterification reactions at room temperature. Prepared for submission to Royal Society of Chemistry (RSC) journal, Green Chemistry as a communication.

Synthesis of Fe–Ni bimetallic nanoparticles from pixel target ablation: plume dynamics and surface characterization

International Nuclear Information System (INIS)

Niu Xiaoxu; Murray, Paul T.; Sarangan, Andrew

2012-01-01

A novel Fe–Ni bimetallic nanoparticle synthesis technique, denoted pixel target ablation, is reported. The technique entails ablating a thin film target consisting of patterned Fe and Ni pixels with a selected ratio using a KrF excimer laser. The laser energy breaks a known amount of target materials into metal atoms, which then form nanoparticles by recombination in the gas phase. Due to the nature of thin-film ablation, splashing of large particles was eliminated with the added benefit of minimizing nanoparticle agglomeration. Plume dynamics and surface characterizations were carried out to exploit the formation of Fe–Ni nanoparticles more fully. The composition was readily controlled by varying the initial relative amount of Fe and Ni target pixels. Synthesis of multi-element nanoparticles by pixel target ablation should be possible with any element combination that can be prepared as a thin-film target.

Regioselective Synthesis of Cellulose Ester Homopolymers

Science.gov (United States)

Daiqiang Xu; Kristen Voiges; Thomas Elder; Petra Mischnick; Kevin J. Edgar

2012-01-01

Regioselective synthesis of cellulose esters is extremely difficult due to the small reactivity differences between cellulose hydroxyl groups, small differences in steric demand between acyl moieties of interest, and the difficulty of attaching and detaching many protecting groups in the presence of cellulose ester moieties without removing the ester groups. Yet the...

Synthesis and characterization of polycaprolactone for anterior cruciate ligament regeneration

Energy Technology Data Exchange (ETDEWEB)

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

Synthesis and characterization of polycaprolactone for anterior cruciate ligament regeneration

International Nuclear Information System (INIS)

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

Synthesis, characterization and catalytic application of silica supported tin oxide nanoparticles for synthesis of 2,4,5-tri and 1,2,4,5-tetrasubstituted imidazoles under solvent-free conditions

Directory of Open Access Journals (Sweden)

Ashok V. Borhade

2017-02-01

Full Text Available Highly efficient and eco-friendly, one pot synthesis of 1,2,4,5-tetra substituted imidazoles and 2,4,5-trisubstituted imidazoles was reported under solvent free conditions using nanocrystalline silica supported tin oxide (SiO2:SnO2 as a catalyst with excellent yield. The present methodology offers several advantages such as mild reaction conditions, short reaction time, good yield, high purity of product, recyclable catalyst without a noticeable decrease in catalytic activity and can be used for large scale synthesis. The synthesized SiO2:SnO2 nanocrystalline catalyst was characterized by XRD, BET surface area and TEM techniques.

Colloidal phytosterols: synthesis, characterization and bioaccessibility

NARCIS (Netherlands)

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

Synthesis, characterization and TG-DSC study of cadmium halides adducts with caffeine

Energy Technology Data Exchange (ETDEWEB)

Farias, Robson F. de; Silva, Ademir O. da; Silva, Umberto G. da

2003-11-28

The synthesis, characterization and TG-DSC study of the compounds CdX{sub 2}{center_dot}ncaff, for which X: Cl, Br and I; n=1 and 2 and caff: caffeine is reported. It is verified that caffeine is coordinated through more than one coordination site, despite the fact that the nitrogen of the imidazole ring is the main coordination site. The following thermal stability trend is observed: Cl>Br>I and monoadducts are more stable than bisadducts. The thermal degradation (td) enthalpies have the values (kJ mol{sup -1}): 58.2 and 71.5; 74.9 and 91.4; 31.1 and 47.5 for Cl, Br and I mono and bisadducts, respectively.

A short designed semi-aromatic organic nanotube – synthesis, chiroptical characterization, and host properties

DEFF Research Database (Denmark)

Wixe, Torbjörn; Christensen, Niels Johan; Lidin, Sven

2014-01-01

to molecular dynamics simulations in chloroform). The synthesis of the tube, a heptamer, is based on a series of Friedländer condensations and the use of pyrido[3,2-d]pyrimidine units as masked 2-amino aldehydes, as a general means to propagate organic tubular structures and the introduction of a methoxy group...... for modification toward solubility and functionalization are described. The electronic CD spectra of the tube and molecular intermediates are correlated with theoretical spectra calculated with time-dependent density functional theory to characterize the chirality of the tube. Both experimental (NMR...

Niobium-Doped Hydroxyapatite Bioceramics: Synthesis, Characterization and In Vitro Cytocompatibility

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Nádia S. V. Capanema

2015-07-01

Full Text Available Doping calcium phosphates with ionic species can play an important role in biological responses promoting alkaline phosphatase activity, and, therefore inducing the generation of new bone. Thus, in this study, the synthesis of niobium-doped hydroxyapatite (Nb-HA nanosize particles obtained by the precipitation process in aqueous media followed by thermal treatment is presented. The bioceramics were extensively characterized by X-ray diffraction, wavelength dispersive X-ray fluorescence spectrometry, Fourier transform infrared spectroscopy, scanning electron microscopy/energy dispersive X-ray spectroscopy analysis, transmission electron microscopy, atomic force microscopy and thermal analysis regarding their chemical composition, structure and morphology. The results showed that the precipitate dried at 110 °C was composed of amorphous calcium phosphate and HA, with polidisperse particles ranging from micro to nano dimensions. After the thermal treatment at 900 °C, the bioceramic system evolved predominantly to HA crystalline phase, with evident features of particle sintering and reduction of surface area. Moreover, the addition of 10 mol% of niobium salt precursor during the synthesis indicated the complete incorporation of the Nb(V species in the HA crystals with detectable changes in the original lattice parameters. Furthermore, the incorporation of Nb ions caused a significant refinement on the average particle size of HA. Finally, the preliminary cytocompatibility response of the biomaterials was accessed by human osteoblast cell culture using MTT and resazurin assays, which demonstrated no cytotoxicity of the Nb-alloyed hydroxyapatite. Thus, these findings seem promising for developing innovative Nb-doped calcium phosphates as artificial biomaterials for potential use in bone replacements and repair.